[release-branch.go1.21] go1.21.2

Change-Id: Ie06bc8d8e8e170f13ed938a33038931513eaf067
Reviewed-on: https://go-review.googlesource.com/c/go/+/533238
Auto-Submit: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

VERSION

@@ -0,0 +1,2 @@
+go1.21.2
+time 2023-09-28T20:21:36Z

api/go1.21.txt

@@ -60,7 +60,9 @@ pkg crypto/tls, method (*QUICConn) Close() error #44886
 pkg crypto/tls, method (*QUICConn) ConnectionState() ConnectionState #44886
 pkg crypto/tls, method (*QUICConn) HandleData(QUICEncryptionLevel, []uint8) error #44886
 pkg crypto/tls, method (*QUICConn) NextEvent() QUICEvent #44886
-pkg crypto/tls, method (*QUICConn) SendSessionTicket(bool) error #60107
+pkg crypto/tls, method (*QUICConn) SendSessionTicket(QUICSessionTicketOptions) error #60107
+pkg crypto/tls, type QUICSessionTicketOptions struct #60107
+pkg crypto/tls, type QUICSessionTicketOptions struct, EarlyData bool #60107
 pkg crypto/tls, method (*QUICConn) SetTransportParameters([]uint8) #44886
 pkg crypto/tls, method (*QUICConn) Start(context.Context) error #44886
 pkg crypto/tls, method (QUICEncryptionLevel) String() string #44886
@@ -219,18 +221,18 @@ pkg log/slog, func Any(string, interface{}) Attr #56345
 pkg log/slog, func AnyValue(interface{}) Value #56345
 pkg log/slog, func Bool(string, bool) Attr #56345
 pkg log/slog, func BoolValue(bool) Value #56345
-pkg log/slog, func DebugCtx(context.Context, string, ...interface{}) #56345
+pkg log/slog, func DebugContext(context.Context, string, ...interface{}) #61200
 pkg log/slog, func Debug(string, ...interface{}) #56345
 pkg log/slog, func Default() *Logger #56345
 pkg log/slog, func Duration(string, time.Duration) Attr #56345
 pkg log/slog, func DurationValue(time.Duration) Value #56345
-pkg log/slog, func ErrorCtx(context.Context, string, ...interface{}) #56345
+pkg log/slog, func ErrorContext(context.Context, string, ...interface{}) #61200
 pkg log/slog, func Error(string, ...interface{}) #56345
 pkg log/slog, func Float64(string, float64) Attr #56345
 pkg log/slog, func Float64Value(float64) Value #56345
 pkg log/slog, func Group(string, ...interface{}) Attr #59204
 pkg log/slog, func GroupValue(...Attr) Value #56345
-pkg log/slog, func InfoCtx(context.Context, string, ...interface{}) #56345
+pkg log/slog, func InfoContext(context.Context, string, ...interface{}) #61200
 pkg log/slog, func Info(string, ...interface{}) #56345
 pkg log/slog, func Int64(string, int64) Attr #56345
 pkg log/slog, func Int64Value(int64) Value #56345
@@ -250,7 +252,7 @@ pkg log/slog, func Time(string, time.Time) Attr #56345
 pkg log/slog, func TimeValue(time.Time) Value #56345
 pkg log/slog, func Uint64(string, uint64) Attr #56345
 pkg log/slog, func Uint64Value(uint64) Value #56345
-pkg log/slog, func WarnCtx(context.Context, string, ...interface{}) #56345
+pkg log/slog, func WarnContext(context.Context, string, ...interface{})  #61200
 pkg log/slog, func Warn(string, ...interface{}) #56345
 pkg log/slog, func With(...interface{}) *Logger #56345
 pkg log/slog, method (Attr) Equal(Attr) bool #56345
@@ -271,17 +273,17 @@ pkg log/slog, method (*LevelVar) MarshalText() ([]uint8, error) #56345
 pkg log/slog, method (*LevelVar) Set(Level) #56345
 pkg log/slog, method (*LevelVar) String() string #56345
 pkg log/slog, method (*LevelVar) UnmarshalText([]uint8) error #56345
-pkg log/slog, method (*Logger) DebugCtx(context.Context, string, ...interface{}) #56345
+pkg log/slog, method (*Logger) DebugContext(context.Context, string, ...interface{}) #61200
 pkg log/slog, method (*Logger) Debug(string, ...interface{}) #56345
 pkg log/slog, method (*Logger) Enabled(context.Context, Level) bool #56345
-pkg log/slog, method (*Logger) ErrorCtx(context.Context, string, ...interface{}) #56345
+pkg log/slog, method (*Logger) ErrorContext(context.Context, string, ...interface{}) #61200
 pkg log/slog, method (*Logger) Error(string, ...interface{}) #56345
 pkg log/slog, method (*Logger) Handler() Handler #56345
-pkg log/slog, method (*Logger) InfoCtx(context.Context, string, ...interface{}) #56345
+pkg log/slog, method (*Logger) InfoContext(context.Context, string, ...interface{}) #61200
 pkg log/slog, method (*Logger) Info(string, ...interface{}) #56345
 pkg log/slog, method (*Logger) LogAttrs(context.Context, Level, string, ...Attr) #56345
 pkg log/slog, method (*Logger) Log(context.Context, Level, string, ...interface{}) #56345
-pkg log/slog, method (*Logger) WarnCtx(context.Context, string, ...interface{}) #56345
+pkg log/slog, method (*Logger) WarnContext(context.Context, string, ...interface{}) #61200
 pkg log/slog, method (*Logger) Warn(string, ...interface{}) #56345
 pkg log/slog, method (*Logger) WithGroup(string) *Logger #56345
 pkg log/slog, method (*Logger) With(...interface{}) *Logger #56345
@@ -344,8 +346,6 @@ pkg maps, func Copy[$0 interface{ ~map[$2]$3 }, $1 interface{ ~map[$2]$3 }, $2 c
 pkg maps, func DeleteFunc[$0 interface{ ~map[$1]$2 }, $1 comparable, $2 interface{}]($0, func($1, $2) bool) #57436
 pkg maps, func Equal[$0 interface{ ~map[$2]$3 }, $1 interface{ ~map[$2]$3 }, $2 comparable, $3 comparable]($0, $1) bool #57436
 pkg maps, func EqualFunc[$0 interface{ ~map[$2]$3 }, $1 interface{ ~map[$2]$4 }, $2 comparable, $3 interface{}, $4 interface{}]($0, $1, func($3, $4) bool) bool #57436
-pkg maps, func Keys[$0 interface{ ~map[$1]$2 }, $1 comparable, $2 interface{}]($0) []$1 #57436
-pkg maps, func Values[$0 interface{ ~map[$1]$2 }, $1 comparable, $2 interface{}]($0) []$2 #57436
 pkg math/big, method (*Int) Float64() (float64, Accuracy) #56984
 pkg net/http, method (*ProtocolError) Is(error) bool #41198
 pkg net/http, method (*ResponseController) EnableFullDuplex() error #57786

codereview.cfg

@@ -1 +1,2 @@
-branch: master
+branch: release-branch.go1.21
+parent-branch: master

doc/go_spec.html

@@ -1,6 +1,6 @@
 <!--{
 	"Title": "The Go Programming Language Specification",
-	"Subtitle": "Version of June 14, 2023",
+	"Subtitle": "Version of Aug 2, 2023",
 	"Path": "/ref/spec"
 }-->
 
@@ -2511,7 +2511,7 @@ type (
 
 <p>
 A type definition creates a new, distinct type with the same
-<a href="#Types">underlying type</a> and operations as the given type
+<a href="#Underlying_types">underlying type</a> and operations as the given type
 and binds an identifier, the <i>type name</i>, to it.
 </p>
 
@@ -4343,7 +4343,7 @@ type parameter list    type arguments    after substitution
 When using a generic function, type arguments may be provided explicitly,
 or they may be partially or completely <a href="#Type_inference">inferred</a>
 from the context in which the function is used.
-Provided that they can be inferred, type arguments may be omitted entirely if the function is:
+Provided that they can be inferred, type argument lists may be omitted entirely if the function is:
 </p>
 
 <ul>
@@ -4351,7 +4351,7 @@ Provided that they can be inferred, type arguments may be omitted entirely if th
 	<a href="#Calls">called</a> with ordinary arguments,
 </li>
 <li>
-	<a href="#Assignment_statements">assigned</a> to a variable with an explicitly declared type,
+	<a href="#Assignment_statements">assigned</a> to a variable with a known type
 </li>
 <li>
 	<a href="#Calls">passed as an argument</a> to another function, or
@@ -4371,7 +4371,7 @@ must be inferrable from the context in which the function is used.
 // sum returns the sum (concatenation, for strings) of its arguments.
 func sum[T ~int | ~float64 | ~string](x... T) T { … }
 
-x := sum                       // illegal: sum must have a type argument (x is a variable without a declared type)
+x := sum                       // illegal: the type of x is unknown
 intSum := sum[int]             // intSum has type func(x... int) int
 a := intSum(2, 3)              // a has value 5 of type int
 b := sum[float64](2.0, 3)      // b has value 5.0 of type float64
@@ -4406,402 +4406,323 @@ For a generic type, all type arguments must always be provided explicitly.
 <h3 id="Type_inference">Type inference</h3>
 
 <p>
-<em>NOTE: This section is not yet up-to-date for Go 1.21.</em>
+A use of a generic function may omit some or all type arguments if they can be
+<i>inferred</i> from the context within which the function is used, including
+the constraints of the function's type parameters.
+Type inference succeeds if it can infer the missing type arguments
+and <a href="#Instantiations">instantiation</a> succeeds with the
+inferred type arguments.
+Otherwise, type inference fails and the program is invalid.
 </p>
 
 <p>
-Missing function type arguments may be <i>inferred</i> by a series of steps, described below.
-Each step attempts to use known information to infer additional type arguments.
-Type inference stops as soon as all type arguments are known.
-After type inference is complete, it is still necessary to substitute all type arguments
-for type parameters and verify that each type argument
-<a href="#Implementing_an_interface">implements</a> the relevant constraint;
-it is possible for an inferred type argument to fail to implement a constraint, in which
-case instantiation fails.
+Type inference uses the type relationships between pairs of types for inference:
+For instance, a function argument must be <a href="#Assignability">assignable</a>
+to its respective function parameter; this establishes a relationship between the
+type of the argument and the type of the parameter.
+If either of these two types contains type parameters, type inference looks for the
+type arguments to substitute the type parameters with such that the assignability
+relationship is satisfied.
+Similarly, type inference uses the fact that a type argument must
+<a href="#Satisfying_a_type_constraint">satisfy</a> the constraint of its respective
+type parameter.
 </p>
 
 <p>
-Type inference is based on
+Each such pair of matched types corresponds to a <i>type equation</i> containing
+one or multiple type parameters, from one or possibly multiple generic functions.
+Inferring the missing type arguments means solving the resulting set of type
+equations for the respective type parameters.
+</p>
+
+<p>
+For example, given
+</p>
+
+<pre>
+// dedup returns a copy of the argument slice with any duplicate entries removed.
+func dedup[S ~[]E, E comparable](S) S { … }
+
+type Slice []int
+var s Slice
+s = dedup(s)   // same as s = dedup[Slice, int](s)
+</pre>
+
+<p>
+the variable <code>s</code> of type <code>Slice</code> must be assignable to
+the function parameter type <code>S</code> for the program to be valid.
+To reduce complexity, type inference ignores the directionality of assignments,
+so the type relationship between <code>Slice</code> and <code>S</code> can be
+expressed via the (symmetric) type equation <code>Slice ≡<sub>A</sub> S</code>
+(or <code>S ≡<sub>A</sub> Slice</code> for that matter),
+where the <code><sub>A</sub></code> in <code>≡<sub>A</sub></code>
+indicates that the LHS and RHS types must match per assignability rules
+(see the section on <a href="#Type_unification">type unification</a> for
+details).
+Similarly, the type parameter <code>S</code> must satisfy its constraint
+<code>~[]E</code>. This can be expressed as <code>S ≡<sub>C</sub> ~[]E</code>
+where <code>X ≡<sub>C</sub> Y</code> stands for
+"<code>X</code> satisfies constraint <code>Y</code>".
+These observations lead to a set of two equations
+</p>
+
+<pre>
+	Slice ≡<sub>A</sub> S      (1)
+	S     ≡<sub>C</sub> ~[]E   (2)
+</pre>
+
+<p>
+which now can be solved for the type parameters <code>S</code> and <code>E</code>.
+From (1) a compiler can infer that the type argument for <code>S</code> is <code>Slice</code>.
+Similarly, because the underlying type of <code>Slice</code> is <code>[]int</code>
+and <code>[]int</code> must match <code>[]E</code> of the constraint,
+a compiler can infer that <code>E</code> must be <code>int</code>.
+Thus, for these two equations, type inference infers
+</p>
+
+<pre>
+	S ➞ Slice
+	E ➞ int
+</pre>
+
+<p>
+Given a set of type equations, the type parameters to solve for are
+the type parameters of the functions that need to be instantiated
+and for which no explicit type arguments is provided.
+These type parameters are called <i>bound</i> type parameters.
+For instance, in the <code>dedup</code> example above, the type parameters
+<code>P</code> and <code>E</code> are bound to <code>dedup</code>.
+An argument to a generic function call may be a generic function itself.
+The type parameters of that function are included in the set of bound
+type parameters.
+The types of function arguments may contain type parameters from other
+functions (such as a generic function enclosing a function call).
+Those type parameters may also appear in type equations but they are
+not bound in that context.
+Type equations are always solved for the bound type parameters only.
+</p>
+
+<p>
+Type inference supports calls of generic functions and assignments
+of generic functions to (explicitly function-typed) variables.
+This includes passing generic functions as arguments to other
+(possibly also generic) functions, and returning generic functions
+as results.
+Type inference operates on a set of equations specific to each of
+these cases.
+The equations are as follows (type argument lists are omitted for clarity):
 </p>
 
 <ul>
 <li>
-	a <a href="#Type_parameter_declarations">type parameter list</a>
+	<p>
+	For a function call <code>f(a<sub>0</sub>, a<sub>1</sub>, …)</code> where
+	<code>f</code> or a function argument <code>a<sub>i</sub></code> is
+	a generic function:
+	<br>
+	Each pair <code>(a<sub>i</sub>, p<sub>i</sub>)</code> of corresponding
+	function arguments and parameters where <code>a<sub>i</sub></code> is not an
+	<a href="#Constants">untyped constant</a> yields an equation
+	<code>typeof(p<sub>i</sub>) ≡<sub>A</sub> typeof(a<sub>i</sub>)</code>.
+	<br>
+	If <code>a<sub>i</sub></code> is an untyped constant <code>c<sub>j</sub></code>,
+	and <code>typeof(p<sub>i</sub>)</code> is a bound type parameter <code>P<sub>k</sub></code>,
+	the pair <code>(c<sub>j</sub>, P<sub>k</sub>)</code> is collected separately from
+	the type equations.
+	</p>
 </li>
 <li>
-	a substitution map <i>M</i> initialized with the known type arguments, if any
+	<p>
+	For an assignment <code>v = f</code> of a generic function <code>f</code> to a
+	(non-generic) variable <code>v</code> of function type:
+	<br>
+	<code>typeof(v) ≡<sub>A</sub> typeof(f)</code>.
+	</p>
 </li>
 <li>
-	a (possibly empty) list of ordinary function arguments (in case of a function call only)
+	<p>
+	For a return statement <code>return …, f, … </code> where <code>f</code> is a
+	generic function returned as a result to a (non-generic) result variable
+	<code>r</code> of function type:
+	<br>
+	<code>typeof(r) ≡<sub>A</sub> typeof(f)</code>.
+	</p>
 </li>
 </ul>
 
 <p>
-and then proceeds with the following steps:
+Additionally, each type parameter <code>P<sub>k</sub></code> and corresponding type constraint
+<code>C<sub>k</sub></code> yields the type equation
+<code>P<sub>k</sub> ≡<sub>C</sub> C<sub>k</sub></code>.
+</p>
+
+<p>
+Type inference gives precedence to type information obtained from typed operands
+before considering untyped constants.
+Therefore, inference proceeds in two phases:
 </p>
 
 <ol>
 <li>
-	apply <a href="#Function_argument_type_inference"><i>function argument type inference</i></a>
-	to all <i>typed</i> ordinary function arguments
+	<p>
+	The type equations are solved for the bound
+	type parameters using <a href="#Type_unification">type unification</a>.
+	If unification fails, type inference fails.
+	</p>
 </li>
 <li>
-	apply <a href="#Constraint_type_inference"><i>constraint type inference</i></a>
-</li>
-<li>
-	apply function argument type inference to all <i>untyped</i> ordinary function arguments
-	using the default type for each of the untyped function arguments
-</li>
-<li>
-	apply constraint type inference
+	<p>
+	For each bound type parameter <code>P<sub>k</sub></code> for which no type argument
+	has been inferred yet and for which one or more pairs
+	<code>(c<sub>j</sub>, P<sub>k</sub>)</code> with that same type parameter
+	were collected, determine the <a href="#Constant_expressions">constant kind</a>
+	of the constants <code>c<sub>j</sub></code> in all those pairs the same way as for
+	<a href="#Constant_expressions">constant expressions</a>.
+	The type argument for <code>P<sub>k</sub></code> is the
+	<a href="#Constants">default type</a> for the determined constant kind.
+	If a constant kind cannot be determined due to conflicting constant kinds,
+	type inference fails.
+	</p>
 </li>
 </ol>
 
 <p>
-If there are no ordinary or untyped function arguments, the respective steps are skipped.
-Constraint type inference is skipped if the previous step didn't infer any new type arguments,
-but it is run at least once if there are missing type arguments.
+If not all type arguments have been found after these two phases, type inference fails.
 </p>
 
 <p>
-The substitution map <i>M</i> is carried through all steps, and each step may add entries to <i>M</i>.
-The process stops as soon as <i>M</i> has a type argument for each type parameter or if an inference step fails.
-If an inference step fails, or if <i>M</i> is still missing type arguments after the last step, type inference fails.
+If the two phases are successful, type inference determined a type argument for each
+bound type parameter:
+</p>
+
+<pre>
+	P<sub>k</sub> ➞ A<sub>k</sub>
+</pre>
+
+<p>
+A type argument <code>A<sub>k</sub></code> may be a composite type,
+containing other bound type parameters <code>P<sub>k</sub></code> as element types
+(or even be just another bound type parameter).
+In a process of repeated simplification, the bound type parameters in each type
+argument are substituted with the respective type arguments for those type
+parameters until each type argument is free of bound type parameters.
+</p>
+
+<p>
+If type arguments contain cyclic references to themselves
+through bound type parameters, simplification and thus type
+inference fails.
+Otherwise, type inference succeeds.
 </p>
 
 <h4 id="Type_unification">Type unification</h4>
 
 <p>
-Type inference is based on <i>type unification</i>. A single unification step
-applies to a <a href="#Type_inference">substitution map</a> and two types, either
-or both of which may be or contain type parameters. The substitution map tracks
-the known (explicitly provided or already inferred) type arguments: the map
-contains an entry <code>P</code> &RightArrow; <code>A</code> for each type
-parameter <code>P</code> and corresponding known type argument <code>A</code>.
-During unification, known type arguments take the place of their corresponding type
-parameters when comparing types. Unification is the process of finding substitution
-map entries that make the two types equivalent.
+Type inference solves type equations through <i>type unification</i>.
+Type unification recursively compares the LHS and RHS types of an
+equation, where either or both types may be or contain bound type parameters,
+and looks for type arguments for those type parameters such that the LHS
+and RHS match (become identical or assignment-compatible, depending on
+context).
+To that effect, type inference maintains a map of bound type parameters
+to inferred type arguments; this map is consulted and updated during type unification.
+Initially, the bound type parameters are known but the map is empty.
+During type unification, if a new type argument <code>A</code> is inferred,
+the respective mapping <code>P ➞ A</code> from type parameter to argument
+is added to the map.
+Conversely, when comparing types, a known type argument
+(a type argument for which a map entry already exists)
+takes the place of its corresponding type parameter.
+As type inference progresses, the map is populated more and more
+until all equations have been considered, or until unification fails.
+Type inference succeeds if no unification step fails and the map has
+an entry for each type parameter.
 </p>
 
-<p>
-For unification, two types that don't contain any type parameters from the current type
-parameter list are <i>equivalent</i>
-if they are identical, or if they are channel types that are identical ignoring channel
-direction, or if their underlying types are equivalent.
-</p>
-
-<p>
-Unification works by comparing the structure of pairs of types: their structure
-disregarding type parameters must be identical, and types other than type parameters
-must be equivalent.
-A type parameter in one type may match any complete subtype in the other type;
-each successful match causes an entry to be added to the substitution map.
-If the structure differs, or types other than type parameters are not equivalent,
-unification fails.
-</p>
-
-<!--
-TODO(gri) Somewhere we need to describe the process of adding an entry to the
-          substitution map: if the entry is already present, the type argument
-	  values are themselves unified.
--->
-
-<p>
-For example, if <code>T1</code> and <code>T2</code> are type parameters,
-<code>[]map[int]bool</code> can be unified with any of the following:
+</pre>
+For example, given the type equation with the bound type parameter
+<code>P</code>
 </p>
 
 <pre>
-[]map[int]bool   // types are identical
-T1               // adds T1 &RightArrow; []map[int]bool to substitution map
-[]T1             // adds T1 &RightArrow; map[int]bool to substitution map
-[]map[T1]T2      // adds T1 &RightArrow; int and T2 &RightArrow; bool to substitution map
+	[10]struct{ elem P, list []P } ≡<sub>A</sub> [10]struct{ elem string; list []string }
 </pre>
 
 <p>
-On the other hand, <code>[]map[int]bool</code> cannot be unified with any of
-</p>
-
-<pre>
-int              // int is not a slice
-struct{}         // a struct is not a slice
-[]struct{}       // a struct is not a map
-[]map[T1]string  // map element types don't match
-</pre>
-
-<p>
-As an exception to this general rule, because a <a href="#Type_definitions">defined type</a>
-<code>D</code> and a type literal <code>L</code> are never equivalent,
-unification compares the underlying type of <code>D</code> with <code>L</code> instead.
-For example, given the defined type
-</p>
-
-<pre>
-type Vector []float64
-</pre>
-
-<p>
-and the type literal <code>[]E</code>, unification compares <code>[]float64</code> with
-<code>[]E</code> and adds an entry <code>E</code> &RightArrow; <code>float64</code> to
-the substitution map.
-</p>
-
-<h4 id="Function_argument_type_inference">Function argument type inference</h4>
-
-<!-- In this section and the section on constraint type inference we start with examples
-rather than have the examples follow the rules as is customary elsewhere in spec.
-Hopefully this helps building an intuition and makes the rules easier to follow. -->
-
-<p>
-Function argument type inference infers type arguments from function arguments:
-if a function parameter is declared with a type <code>T</code> that uses
-type parameters,
-<a href="#Type_unification">unifying</a> the type of the corresponding
-function argument with <code>T</code> may infer type arguments for the type
-parameters used by <code>T</code>.
+type inference starts with an empty map.
+Unification first compares the top-level structure of the LHS and RHS
+types.
+Both are arrays of the same length; they unify if the element types unify.
+Both element types are structs; they unify if they have
+the same number of fields with the same names and if the
+field types unify.
+The type argument for <code>P</code> is not known yet (there is no map entry),
+so unifying <code>P</code> with <code>string</code> adds
+the mapping <code>P ➞ string</code> to the map.
+Unifying the types of the <code>list</code> field requires
+unifying <code>[]P</code> and <code>[]string</code> and
+thus <code>P</code> and <code>string</code>.
+Since the type argument for <code>P</code> is known at this point
+(there is a map entry for <code>P</code>), its type argument
+<code>string</code> takes the place of <code>P</code>.
+And since <code>string</code> is identical to <code>string</code>,
+this unification step succeeds as well.
+Unification of the LHS and RHS of the equation is now finished.
+Type inference succeeds because there is only one type equation,
+no unification step failed, and the map is fully populated.
 </p>
 
 <p>
-For instance, given the generic function
-</p>
-
-<pre>
-func scale[Number ~int64|~float64|~complex128](v []Number, s Number) []Number
-</pre>
-
-<p>
-and the call
-</p>
-
-<pre>
-var vector []float64
-scaledVector := scale(vector, 42)
-</pre>
-
-<p>
-the type argument for <code>Number</code> can be inferred from the function argument
-<code>vector</code> by unifying the type of <code>vector</code> with the corresponding
-parameter type: <code>[]float64</code> and <code>[]Number</code>
-match in structure and <code>float64</code> matches with <code>Number</code>.
-This adds the entry <code>Number</code> &RightArrow; <code>float64</code> to the
-<a href="#Type_unification">substitution map</a>.
-Untyped arguments, such as the second function argument <code>42</code> here, are ignored
-in the first round of function argument type inference and only considered if there are
-unresolved type parameters left.
+Unification uses a combination of <i>exact</i> and <i>loose</i>
+unification depending on whether two types have to be
+<a href="#Type_identity">identical</a>,
+<a href="#Assignability">assignment-compatible</a>, or
+only structurally equal.
+The respective <a href="#Type_unification_rules">type unification rules</a>
+are spelled out in detail in the <a href="#Appendix">Appendix</a>.
 </p>
 
 <p>
-Inference happens in two separate phases; each phase operates on a specific list of
-(parameter, argument) pairs:
+For an equation of the form <code>X ≡<sub>A</sub> Y</code>,
+where <code>X</code> and <code>Y</code> are types involved
+in an assignment (including parameter passing and return statements),
+the top-level type structures may unify loosely but element types
+must unify exactly, matching the rules for assignments.
 </p>
 
-<ol>
+<p>
+For an equation of the form <code>P ≡<sub>C</sub> C</code>,
+where <code>P</code> is a type parameter and <code>C</code>
+its corresponding constraint, the unification rules are bit
+more complicated:
+</p>
+
+<ul>
 <li>
-	The list <i>Lt</i> contains all (parameter, argument) pairs where the parameter
-	type uses type parameters and where the function argument is <i>typed</i>.
+	If <code>C</code> has a <a href="#Core_types">core type</a>
+	<code>core(C)</code>
+	and <code>P</code> has a known type argument <code>A</code>,
+	<code>core(C)</code> and <code>A</code> must unify loosely.
+	If <code>P</code> does not have a known type argument
+	and <code>C</code> contains exactly one type term <code>T</code>
+	that is not an underlying (tilde) type, unification adds the
+	mapping <code>P ➞ T</code> to the map.
 </li>
 <li>
-	The list <i>Lu</i> contains all remaining pairs where the parameter type is a single
-	type parameter. In this list, the respective function arguments are untyped.
+	If <code>C</code> does not have a core type
+	and <code>P</code> has a known type argument <code>A</code>,
+	<code>A</code> must have all methods of <code>C</code>, if any,
+	and corresponding method types must unify exactly.
 </li>
-</ol>
+</ul>
 
 <p>
-Any other (parameter, argument) pair is ignored.
-</p>
-
-<p>
-By construction, the arguments of the pairs in <i>Lu</i> are <i>untyped</i> constants
-(or the untyped boolean result of a comparison). And because <a href="#Constants">default types</a>
-of untyped values are always predeclared non-composite types, they can never match against
-a composite type, so it is sufficient to only consider parameter types that are single type
-parameters.
-</p>
-
-<p>
-Each list is processed in a separate phase:
-</p>
-
-<ol>
-<li>
-	In the first phase, the parameter and argument types of each pair in <i>Lt</i>
-	are unified. If unification succeeds for a pair, it may yield new entries that
-	are added to the substitution map <i>M</i>. If unification fails, type inference
-	fails.
-</li>
-<li>
-	The second phase considers the entries of list <i>Lu</i>. Type parameters for
-	which the type argument has already been determined are ignored in this phase.
-	For each remaining pair, the parameter type (which is a single type parameter) and
-	the <a href="#Constants">default type</a> of the corresponding untyped argument is
-	unified. If unification fails, type inference fails.
-</li>
-</ol>
-
-<p>
-While unification is successful, processing of each list continues until all list elements
-are considered, even if all type arguments are inferred before the last list element has
-been processed.
-</p>
-
-<p>
-Example:
-</p>
-
-<pre>
-func min[T ~int|~float64](x, y T) T
-
-var x int
-min(x, 2.0)    // T is int, inferred from typed argument x; 2.0 is assignable to int
-min(1.0, 2.0)  // T is float64, inferred from default type for 1.0 and matches default type for 2.0
-min(1.0, 2)    // illegal: default type float64 (for 1.0) doesn't match default type int (for 2)
-</pre>
-
-<p>
-In the example <code>min(1.0, 2)</code>, processing the function argument <code>1.0</code>
-yields the substitution map entry <code>T</code> &RightArrow; <code>float64</code>. Because
-processing continues until all untyped arguments are considered, an error is reported. This
-ensures that type inference does not depend on the order of the untyped arguments.
-</p>
-
-<h4 id="Constraint_type_inference">Constraint type inference</h4>
-
-<p>
-Constraint type inference infers type arguments by considering type constraints.
-If a type parameter <code>P</code> has a constraint with a
-<a href="#Core_types">core type</a> <code>C</code>,
-<a href="#Type_unification">unifying</a> <code>P</code> with <code>C</code>
-may infer additional type arguments, either the type argument for <code>P</code>,
-or if that is already known, possibly the type arguments for type parameters
-used in <code>C</code>.
-</p>
-
-<p>
-For instance, consider the type parameter list with type parameters <code>List</code> and
-<code>Elem</code>:
-</p>
-
-<pre>
-[List ~[]Elem, Elem any]
-</pre>
-
-<p>
-Constraint type inference can deduce the type of <code>Elem</code> from the type argument
-for <code>List</code> because <code>Elem</code> is a type parameter in the core type
-<code>[]Elem</code> of <code>List</code>.
-If the type argument is <code>Bytes</code>:
-</p>
-
-<pre>
-type Bytes []byte
-</pre>
-
-<p>
-unifying the underlying type of <code>Bytes</code> with the core type means
-unifying <code>[]byte</code> with <code>[]Elem</code>. That unification succeeds and yields
-the <a href="#Type_unification">substitution map</a> entry
-<code>Elem</code> &RightArrow; <code>byte</code>.
-Thus, in this example, constraint type inference can infer the second type argument from the
-first one.
-</p>
-
-<p>
-Using the core type of a constraint may lose some information: In the (unlikely) case that
-the constraint's type set contains a single <a href="#Type_definitions">defined type</a>
-<code>N</code>, the corresponding core type is <code>N</code>'s underlying type rather than
-<code>N</code> itself. In this case, constraint type inference may succeed but instantiation
-will fail because the inferred type is not in the type set of the constraint.
-Thus, constraint type inference uses the <i>adjusted core type</i> of
-a constraint: if the type set contains a single type, use that type; otherwise use the
-constraint's core type.
-</p>
-
-<p>
-Generally, constraint type inference proceeds in two phases: Starting with a given
-substitution map <i>M</i>
-</p>
-
-<ol>
-<li>
-For all type parameters with an adjusted core type, unify the type parameter with that
-type. If any unification fails, constraint type inference fails.
-</li>
-
-<li>
-At this point, some entries in <i>M</i> may map type parameters to other
-type parameters or to types containing type parameters. For each entry
-<code>P</code> &RightArrow; <code>A</code> in <i>M</i> where <code>A</code> is or
-contains type parameters <code>Q</code> for which there exist entries
-<code>Q</code> &RightArrow; <code>B</code> in <i>M</i>, substitute those
-<code>Q</code> with the respective <code>B</code> in <code>A</code>.
-Stop when no further substitution is possible.
-</li>
-</ol>
-
-<p>
-The result of constraint type inference is the final substitution map <i>M</i> from type
-parameters <code>P</code> to type arguments <code>A</code> where no type parameter <code>P</code>
-appears in any of the <code>A</code>.
-</p>
-
-<p>
-For instance, given the type parameter list
-</p>
-
-<pre>
-[A any, B []C, C *A]
-</pre>
-
-<p>
-and the single provided type argument <code>int</code> for type parameter <code>A</code>,
-the initial substitution map <i>M</i> contains the entry <code>A</code> &RightArrow; <code>int</code>.
-</p>
-
-<p>
-In the first phase, the type parameters <code>B</code> and <code>C</code> are unified
-with the core type of their respective constraints. This adds the entries
-<code>B</code> &RightArrow; <code>[]C</code> and <code>C</code> &RightArrow; <code>*A</code>
-to <i>M</i>.
-
-<p>
-At this point there are two entries in <i>M</i> where the right-hand side
-is or contains type parameters for which there exists other entries in <i>M</i>:
-<code>[]C</code> and <code>*A</code>.
-In the second phase, these type parameters are replaced with their respective
-types. It doesn't matter in which order this happens. Starting with the state
-of <i>M</i> after the first phase:
-</p>
-
-<p>
-<code>A</code> &RightArrow; <code>int</code>,
-<code>B</code> &RightArrow; <code>[]C</code>,
-<code>C</code> &RightArrow; <code>*A</code>
-</p>
-
-<p>
-Replace <code>A</code> on the right-hand side of &RightArrow; with <code>int</code>:
-</p>
-
-<p>
-<code>A</code> &RightArrow; <code>int</code>,
-<code>B</code> &RightArrow; <code>[]C</code>,
-<code>C</code> &RightArrow; <code>*int</code>
-</p>
-
-<p>
-Replace <code>C</code> on the right-hand side of &RightArrow; with <code>*int</code>:
-</p>
-
-<p>
-<code>A</code> &RightArrow; <code>int</code>,
-<code>B</code> &RightArrow; <code>[]*int</code>,
-<code>C</code> &RightArrow; <code>*int</code>
-</p>
-
-<p>
-At this point no further substitution is possible and the map is full.
-Therefore, <code>M</code> represents the final map of type parameters
-to type arguments for the given type parameter list.
+When solving type equations from type constraints,
+solving one equation may infer additional type arguments,
+which in turn may enable solving other equations that depend
+on those type arguments.
+Type inference repeats type unification as long as new type
+arguments are inferred.
 </p>
 
 <h3 id="Operators">Operators</h3>
@@ -5479,7 +5400,7 @@ in any of these cases:
 	ignoring struct tags (see below),
 	<code>x</code>'s type and <code>T</code> are not
 	<a href="#Type_parameter_declarations">type parameters</a> but have
-	<a href="#Type_identity">identical</a> <a href="#Types">underlying types</a>.
+	<a href="#Type_identity">identical</a> <a href="#Underlying_types">underlying types</a>.
 	</li>
 	<li>
 	ignoring struct tags (see below),
@@ -7324,7 +7245,8 @@ clear(t)    type parameter    see below
 </pre>
 
 <p>
-If the argument type is a <a href="#Type_parameter_declarations">type parameter</a>,
+If the type of the argument to <code>clear</code> is a
+<a href="#Type_parameter_declarations">type parameter</a>,
 all types in its type set must be maps or slices, and <code>clear</code>
 performs the operation corresponding to the actual type argument.
 </p>
@@ -8290,7 +8212,7 @@ of if the general conversion rules take care of this.
 <p>
 A <code>Pointer</code> is a <a href="#Pointer_types">pointer type</a> but a <code>Pointer</code>
 value may not be <a href="#Address_operators">dereferenced</a>.
-Any pointer or value of <a href="#Types">underlying type</a> <code>uintptr</code> can be
+Any pointer or value of <a href="#Underlying_types">underlying type</a> <code>uintptr</code> can be
 <a href="#Conversions">converted</a> to a type of underlying type <code>Pointer</code> and vice versa.
 The effect of converting between <code>Pointer</code> and <code>uintptr</code> is implementation-defined.
 </p>
@@ -8438,3 +8360,145 @@ The following minimal alignment properties are guaranteed:
 <p>
 A struct or array type has size zero if it contains no fields (or elements, respectively) that have a size greater than zero. Two distinct zero-size variables may have the same address in memory.
 </p>
+
+<h2 id="Appendix">Appendix</h2>
+
+<h3 id="Type_unification_rules">Type unification rules</h3>
+
+<p>
+The type unification rules describe if and how two types unify.
+The precise details are relevant for Go implementations,
+affect the specifics of error messages (such as whether
+a compiler reports a type inference or other error),
+and may explain why type inference fails in unusual code situations.
+But by and large these rules can be ignored when writing Go code:
+type inference is designed to mostly "work as expected",
+and the unification rules are fine-tuned accordingly.
+</p>
+
+<p>
+Type unification is controlled by a <i>matching mode</i>, which may
+be <i>exact</i> or <i>loose</i>.
+As unification recursively descends a composite type structure,
+the matching mode used for elements of the type, the <i>element matching mode</i>,
+remains the same as the matching mode except when two types are unified for
+<a href="#Assignability">assignability</a> (<code>≡<sub>A</sub></code>):
+in this case, the matching mode is <i>loose</i> at the top level but
+then changes to <i>exact</i> for element types, reflecting the fact
+that types don't have to be identical to be assignable.
+</p>
+
+<p>
+Two types that are not bound type parameters unify exactly if any of
+following conditions is true:
+</p>
+
+<ul>
+<li>
+	Both types are <a href="#Type_identity">identical</a>.
+</li>
+<li>
+	Both types have identical structure and their element types
+	unify exactly.
+</li>
+<li>
+	Exactly one type is an <a href="#Type_inference">unbound</a>
+	type parameter with a <a href="#Core_types">core type</a>,
+	and that core type unifies with the other type per the
+	unification rules for <code>≡<sub>A</sub></code>
+	(loose unification at the top level and exact unification
+	for element types).
+</li>
+</ul>
+
+<p>
+If both types are bound type parameters, they unify per the given
+matching modes if:
+</p>
+
+<ul>
+<li>
+	Both type parameters are identical.
+</li>
+<li>
+	At most one of the type parameters has a known type argument.
+	In this case, the type parameters are <i>joined</i>:
+	they both stand for the same type argument.
+	If neither type parameter has a known type argument yet,
+	a future type argument inferred for one the type parameters
+	is simultaneously inferred for both of them.
+</li>
+<li>
+	Both type parameters have a known type argument
+	and the type arguments unify per the given matching modes.
+</li>
+</ul>
+
+<p>
+A single bound type parameter <code>P</code> and another type <code>T</code> unify
+per the given matching modes if:
+</p>
+
+<ul>
+<li>
+	<code>P</code> doesn't have a known type argument.
+	In this case, <code>T</code> is inferred as the type argument for <code>P</code>.
+</li>
+<li>
+	<code>P</code> does have a known type argument <code>A</code>,
+	<code>A</code> and <code>T</code> unify per the given matching modes,
+	and one of the following conditions is true:
+	<ul>
+	<li>
+		Both <code>A</code> and <code>T</code> are interface types:
+		In this case, if both <code>A</code> and <code>T</code> are
+		also <a href="#Type_definitions">defined</a> types,
+		they must be <a href="#Type_identity">identical</a>.
+		Otherwise, if neither of them is a defined type, they must
+		have the same number of methods
+		(unification of <code>A</code> and <code>T</code> already
+		established that the methods match).
+	</li>
+	<li>
+		Neither <code>A</code> nor <code>T</code> are interface types:
+		In this case, if <code>T</code> is a defined type, <code>T</code>
+		replaces <code>A</code> as the inferred type argument for <code>P</code>.
+	</li>
+	</ul>
+</li>
+</ul>
+
+<p>
+Finally, two types that are not bound type parameters unify loosely
+(and per the element matching mode) if:
+</p>
+
+<ul>
+<li>
+	Both types unify exactly.
+</li>
+<li>
+	One type is a <a href="#Type_definitions">defined type</a>,
+	the other type is a type literal, but not an interface,
+	and their underlying types unify per the element matching mode.
+</li>
+<li>
+	Both types are interfaces (but not type parameters) with
+	identical <a href="#Interface_types">type terms</a>,
+	both or neither embed the predeclared type
+	<a href="#Predeclared_identifiers">comparable</a>,
+	corresponding method types unify per the element matching mode,
+	and the method set of one of the interfaces is a subset of
+	the method set of the other interface.
+</li>
+<li>
+	Only one type is an interface (but not a type parameter),
+	corresponding methods of the two types unify per the element matching mode,
+	and the method set of the interface is a subset of
+	the method set of the other type.
+</li>
+<li>
+	Both types have the same structure and their element types
+	unify per the element matching mode.
+</li>
+</ul>

doc/godebug.md

@@ -126,6 +126,14 @@ for example,
 see the [runtime documentation](/pkg/runtime#hdr-Environment_Variables)
 and the [go command documentation](/cmd/go#hdr-Build_and_test_caching).
 
+### Go 1.22
+
+Go 1.22 adds a configurable limit to control the maximum acceptable RSA key size
+that can be used in TLS handshakes, controlled by the [`tlsmaxrsasize`setting](/pkg/crypto/tls#Conn.Handshake).
+The default is tlsmaxrsasize=8192, limiting RSA to 8192-bit keys. To avoid
+denial of service attacks, this setting and default was backported to Go
+1.19.13, Go 1.20.8, and Go 1.21.1.
+
 ### Go 1.21
 
 Go 1.21 made it a run-time error to call `panic` with a nil interface value,
@@ -142,6 +150,10 @@ forms, controlled by the
 respectively.
 This behavior was backported to Go 1.19.8+ and Go 1.20.3+.
 
+Go 1.21 adds the support of Multipath TCP but it is only used if the application
+explicitly asked for it. This behavior can be controlled by the
+[`multipathtcp` setting](/pkg/net#Dialer.SetMultipathTCP).
+
 There is no plan to remove any of these settings.
 
 ### Go 1.20

misc/wasm/go_wasip1_wasm_exec

@@ -10,12 +10,12 @@ case "$GOWASIRUNTIME" in
 	"wasmer")
 		exec wasmer run --dir=/ --env PWD="$PWD" --env PATH="$PATH" ${GOWASIRUNTIMEARGS:-} "$1" -- "${@:2}"
 		;;
-	"wasmtime")
-		exec wasmtime run --dir=/ --env PWD="$PWD" --env PATH="$PATH" --max-wasm-stack 1048576 ${GOWASIRUNTIMEARGS:-} "$1" -- "${@:2}"
-		;;
-	"wazero" | "")
+	"wazero")
 		exec wazero run -mount /:/ -env-inherit -cachedir "${TMPDIR:-/tmp}"/wazero ${GOWASIRUNTIMEARGS:-} "$1" "${@:2}"
 		;;
+	"wasmtime" | "")
+		exec wasmtime run --dir=/ --env PWD="$PWD" --env PATH="$PATH" --max-wasm-stack 1048576 ${GOWASIRUNTIMEARGS:-} "$1" -- "${@:2}"
+		;;
 	*)
 		echo "Unknown Go WASI runtime specified: $GOWASIRUNTIME"
 		exit 1

src/README.vendor

@@ -38,7 +38,7 @@ The vendor directory may be updated with 'go mod vendor'.
 A typical sequence might be:
 
     cd src
-    go get golang.org/x/net@latest
+    go get golang.org/x/net@master
     go mod tidy
     go mod vendor
 

src/bytes/compare_test.go

@@ -7,7 +7,6 @@ package bytes_test
 import (
 	. "bytes"
 	"fmt"
-	"internal/testenv"
 	"testing"
 )
 
@@ -73,7 +72,7 @@ func TestCompareBytes(t *testing.T) {
 	}
 	lengths = append(lengths, 256, 512, 1024, 1333, 4095, 4096, 4097)
 
-	if !testing.Short() || testenv.Builder() != "" {
+	if !testing.Short() {
 		lengths = append(lengths, 65535, 65536, 65537, 99999)
 	}
 

src/cmd/api/api_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package api
+package main
 
 import (
 	"flag"

src/cmd/api/boring_test.go

@@ -4,7 +4,7 @@
 
 //go:build boringcrypto
 
-package api
+package main
 
 import (
 	"fmt"

src/cmd/api/main_test.go

@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package api computes the exported API of a set of Go packages.
+// This package computes the exported API of a set of Go packages.
 // It is only a test, not a command, nor a usefully importable package.
-package api
+
+package main
 
 import (
 	"bufio"

src/cmd/asm/internal/asm/testdata/riscv64.s

@@ -183,28 +183,28 @@ start:
 	// 8.2: Load-Reserved/Store-Conditional
 	LRW	(X5), X6				// 2fa30214
 	LRD	(X5), X6				// 2fb30214
-	SCW	X5, (X6), X7				// af23531c
-	SCD	X5, (X6), X7				// af33531c
+	SCW	X5, (X6), X7				// af23531a
+	SCD	X5, (X6), X7				// af33531a
 
 	// 8.3: Atomic Memory Operations
-	AMOSWAPW	X5, (X6), X7			// af23530c
-	AMOSWAPD	X5, (X6), X7			// af33530c
-	AMOADDW		X5, (X6), X7			// af235304
-	AMOADDD		X5, (X6), X7			// af335304
-	AMOANDW		X5, (X6), X7			// af235364
-	AMOANDD		X5, (X6), X7			// af335364
-	AMOORW		X5, (X6), X7			// af235344
-	AMOORD		X5, (X6), X7			// af335344
-	AMOXORW		X5, (X6), X7			// af235324
-	AMOXORD		X5, (X6), X7			// af335324
-	AMOMAXW		X5, (X6), X7			// af2353a4
-	AMOMAXD		X5, (X6), X7			// af3353a4
-	AMOMAXUW	X5, (X6), X7			// af2353e4
-	AMOMAXUD	X5, (X6), X7			// af3353e4
-	AMOMINW		X5, (X6), X7			// af235384
-	AMOMIND		X5, (X6), X7			// af335384
-	AMOMINUW	X5, (X6), X7			// af2353c4
-	AMOMINUD	X5, (X6), X7			// af3353c4
+	AMOSWAPW	X5, (X6), X7			// af23530e
+	AMOSWAPD	X5, (X6), X7			// af33530e
+	AMOADDW		X5, (X6), X7			// af235306
+	AMOADDD		X5, (X6), X7			// af335306
+	AMOANDW		X5, (X6), X7			// af235366
+	AMOANDD		X5, (X6), X7			// af335366
+	AMOORW		X5, (X6), X7			// af235346
+	AMOORD		X5, (X6), X7			// af335346
+	AMOXORW		X5, (X6), X7			// af235326
+	AMOXORD		X5, (X6), X7			// af335326
+	AMOMAXW		X5, (X6), X7			// af2353a6
+	AMOMAXD		X5, (X6), X7			// af3353a6
+	AMOMAXUW	X5, (X6), X7			// af2353e6
+	AMOMAXUD	X5, (X6), X7			// af3353e6
+	AMOMINW		X5, (X6), X7			// af235386
+	AMOMIND		X5, (X6), X7			// af335386
+	AMOMINUW	X5, (X6), X7			// af2353c6
+	AMOMINUD	X5, (X6), X7			// af3353c6
 
 	// 10.1: Base Counters and Timers
 	RDCYCLE		X5				// f32200c0

src/cmd/cgo/internal/test/issue8756.go

@@ -1,7 +1,7 @@
 package cgotest
 
 /*
-#cgo LDFLAGS: -lm
+#cgo !darwin LDFLAGS: -lm
 #include <math.h>
 */
 import "C"

src/cmd/cgo/internal/test/issue8756/issue8756.go

@@ -1,7 +1,7 @@
 package issue8756
 
 /*
-#cgo LDFLAGS: -lm
+#cgo !darwin LDFLAGS: -lm
 #include <math.h>
 */
 import "C"

src/cmd/cgo/internal/test/test.go

@@ -23,7 +23,7 @@ package cgotest
 #include <unistd.h>
 #include <sys/stat.h>
 #include <errno.h>
-#cgo LDFLAGS: -lm
+#cgo !darwin LDFLAGS: -lm
 
 #ifndef WIN32
 #include <pthread.h>

src/cmd/cgo/internal/testerrors/errors_test.go

@@ -111,6 +111,7 @@ func TestReportsTypeErrors(t *testing.T) {
 	for _, file := range []string{
 		"err1.go",
 		"err2.go",
+		"err5.go",
 		"issue11097a.go",
 		"issue11097b.go",
 		"issue18452.go",

src/cmd/cgo/internal/testerrors/testdata/err5.go

@@ -0,0 +1,10 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+//line /tmp/_cgo_.go:1
+//go:cgo_dynamic_linker "/elf/interp" // ERROR HERE: only allowed in cgo-generated code
+
+func main() {}

src/cmd/cgo/internal/testplugin/plugin_test.go

@@ -389,9 +389,18 @@ func TestForkExec(t *testing.T) {
 	}
 }
 
-func TestGeneric(t *testing.T) {
+func TestSymbolNameMangle(t *testing.T) {
 	// Issue 58800: generic function name may contain weird characters
 	// that confuse the external linker.
+	// Issue 62098: the name mangling code doesn't handle some string
+	// symbols correctly.
 	globalSkip(t)
-	goCmd(t, "build", "-buildmode=plugin", "-o", "generic.so", "./generic/plugin.go")
+	goCmd(t, "build", "-buildmode=plugin", "-o", "mangle.so", "./mangle/plugin.go")
+}
+
+func TestIssue62430(t *testing.T) {
+	globalSkip(t)
+	goCmd(t, "build", "-buildmode=plugin", "-o", "issue62430.so", "./issue62430/plugin.go")
+	goCmd(t, "build", "-o", "issue62430.exe", "./issue62430/main.go")
+	run(t, "./issue62430.exe")
 }

src/cmd/cgo/internal/testplugin/testdata/issue62430/main.go

@@ -0,0 +1,35 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Issue 62430: a program that uses plugins may appear
+// to have no references to an initialized global map variable defined
+// in some stdlib package (ex: unicode), however there
+// may be references to that map var from a plugin that
+// gets loaded.
+
+package main
+
+import (
+	"fmt"
+	"plugin"
+	"unicode"
+)
+
+func main() {
+	p, err := plugin.Open("issue62430.so")
+	if err != nil {
+		panic(err)
+	}
+	s, err := p.Lookup("F")
+	if err != nil {
+		panic(err)
+	}
+
+	f := s.(func(string) *unicode.RangeTable)
+	if f("C") == nil {
+		panic("unicode.Categories not properly initialized")
+	} else {
+		fmt.Println("unicode.Categories properly initialized")
+	}
+}

src/cmd/cgo/internal/testplugin/testdata/issue62430/plugin.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"unicode"
+)
+
+func F(s string) *unicode.RangeTable {
+	return unicode.Categories[s]
+}
+
+func main() {}

src/cmd/cgo/internal/testplugin/testdata/mangle/plugin.go

@@ -2,21 +2,37 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Instantiated function name may contain weird characters
-// that confuse the external linker, so it needs to be
-// mangled.
+// Test cases for symbol name mangling.
 
 package main
 
-//go:noinline
-func F[T any]() {}
+import (
+	"fmt"
+	"strings"
+)
 
+// Issue 58800:
+// Instantiated function name may contain weird characters
+// that confuse the external linker, so it needs to be
+// mangled.
 type S struct {
 	X int `parser:"|@@)"`
 }
 
+//go:noinline
+func F[T any]() {}
+
 func P() {
 	F[S]()
 }
 
+// Issue 62098: the name mangling code doesn't handle some string
+// symbols correctly.
+func G(id string) error {
+	if strings.ContainsAny(id, "&$@;/:+,?\\{^}%`]\">[~<#|") {
+		return fmt.Errorf("invalid")
+	}
+	return nil
+}
+
 func main() {}

src/cmd/compile/internal/noder/noder.go

@@ -333,8 +333,14 @@ func (p *noder) pragma(pos syntax.Pos, blankLine bool, text string, old syntax.P
 // contain cgo directives, and for security reasons
 // (primarily misuse of linker flags), other files are not.
 // See golang.org/issue/23672.
+// Note that cmd/go ignores files whose names start with underscore,
+// so the only _cgo_ files we will see from cmd/go are generated by cgo.
+// It's easy to bypass this check by calling the compiler directly;
+// we only protect against uses by cmd/go.
 func isCgoGeneratedFile(pos syntax.Pos) bool {
-	return strings.HasPrefix(filepath.Base(trimFilename(pos.Base())), "_cgo_")
+	// We need the absolute file, independent of //line directives,
+	// so we call pos.Base().Pos().
+	return strings.HasPrefix(filepath.Base(trimFilename(pos.Base().Pos().Base())), "_cgo_")
 }
 
 // safeArg reports whether arg is a "safe" command-line argument,

src/cmd/compile/internal/ssa/_gen/ARM64.rules

@@ -1552,33 +1552,27 @@
 (GreaterEqualU (FlagConstant [fc])) => (MOVDconst [b2i(fc.uge())])
 
 // absorb InvertFlags into boolean values
-(Equal         (InvertFlags x)) => (Equal x)
-(NotEqual      (InvertFlags x)) => (NotEqual x)
-(LessThan      (InvertFlags x)) => (GreaterThan x)
-(LessThanU     (InvertFlags x)) => (GreaterThanU x)
-(GreaterThan   (InvertFlags x)) => (LessThan x)
-(GreaterThanU  (InvertFlags x)) => (LessThanU x)
-(LessEqual     (InvertFlags x)) => (GreaterEqual x)
-(LessEqualU    (InvertFlags x)) => (GreaterEqualU x)
-(GreaterEqual  (InvertFlags x)) => (LessEqual x)
-(GreaterEqualU (InvertFlags x)) => (LessEqualU x)
-(LessThanF     (InvertFlags x)) => (GreaterThanF x)
-(LessEqualF    (InvertFlags x)) => (GreaterEqualF x)
-(GreaterThanF  (InvertFlags x)) => (LessThanF x)
-(GreaterEqualF (InvertFlags x)) => (LessEqualF x)
+(Equal            (InvertFlags x)) => (Equal x)
+(NotEqual         (InvertFlags x)) => (NotEqual x)
+(LessThan         (InvertFlags x)) => (GreaterThan x)
+(LessThanU        (InvertFlags x)) => (GreaterThanU x)
+(GreaterThan      (InvertFlags x)) => (LessThan x)
+(GreaterThanU     (InvertFlags x)) => (LessThanU x)
+(LessEqual        (InvertFlags x)) => (GreaterEqual x)
+(LessEqualU       (InvertFlags x)) => (GreaterEqualU x)
+(GreaterEqual     (InvertFlags x)) => (LessEqual x)
+(GreaterEqualU    (InvertFlags x)) => (LessEqualU x)
+(LessThanF        (InvertFlags x)) => (GreaterThanF x)
+(LessEqualF       (InvertFlags x)) => (GreaterEqualF x)
+(GreaterThanF     (InvertFlags x)) => (LessThanF x)
+(GreaterEqualF    (InvertFlags x)) => (LessEqualF x)
+(LessThanNoov     (InvertFlags x)) => (BIC (GreaterEqualNoov <typ.Bool> x) (Equal <typ.Bool> x))
+(GreaterEqualNoov (InvertFlags x)) => (OR (LessThanNoov <typ.Bool> x) (Equal <typ.Bool> x))
 
 // Boolean-generating instructions (NOTE: NOT all boolean Values) always
 // zero upper bit of the register; no need to zero-extend
 (MOVBUreg x:((Equal|NotEqual|LessThan|LessThanU|LessThanF|LessEqual|LessEqualU|LessEqualF|GreaterThan|GreaterThanU|GreaterThanF|GreaterEqual|GreaterEqualU|GreaterEqualF) _)) => (MOVDreg x)
 
-// omit unsign extension
-(MOVWUreg x) && zeroUpper32Bits(x, 3) => x
-
-// omit sign extension
-(MOVWreg <t> (ANDconst x [c])) && uint64(c) & uint64(0xffffffff80000000) == 0 => (ANDconst <t> x [c])
-(MOVHreg <t> (ANDconst x [c])) && uint64(c) & uint64(0xffffffffffff8000) == 0 => (ANDconst <t> x [c])
-(MOVBreg <t> (ANDconst x [c])) && uint64(c) & uint64(0xffffffffffffff80) == 0 => (ANDconst <t> x [c])
-
 // absorb flag constants into conditional instructions
 (CSEL  [cc] x _ flag) && ccARM64Eval(cc, flag) > 0 => x
 (CSEL  [cc] _ y flag) && ccARM64Eval(cc, flag) < 0 => y

src/cmd/compile/internal/ssa/_gen/ARM64Ops.go

@@ -13,7 +13,6 @@ import "strings"
 //  - *const instructions may use a constant larger than the instruction can encode.
 //    In this case the assembler expands to multiple instructions and uses tmp
 //    register (R27).
-//  - All 32-bit Ops will zero the upper 32 bits of the destination register.
 
 // Suffixes encode the bit width of various instructions.
 // D (double word) = 64 bit

src/cmd/compile/internal/ssa/_gen/PPC64.rules

@@ -588,16 +588,16 @@
 
 // small and of zero-extend => either zero-extend or small and
 (Select0 (ANDCCconst [c] y:(MOVBZreg _))) && c&0xFF == 0xFF => y
-(Select0 (ANDCCconst [0xFF] y:(MOVBreg _))) => y
+(Select0 (ANDCCconst [0xFF] (MOVBreg x))) => (MOVBZreg x)
 (Select0 (ANDCCconst [c] y:(MOVHZreg _)))  && c&0xFFFF == 0xFFFF => y
-(Select0 (ANDCCconst [0xFFFF] y:(MOVHreg _))) => y
+(Select0 (ANDCCconst [0xFFFF] (MOVHreg x))) => (MOVHZreg x)
 
 (AND (MOVDconst [c]) y:(MOVWZreg _))  && c&0xFFFFFFFF == 0xFFFFFFFF => y
 (AND (MOVDconst [0xFFFFFFFF]) y:(MOVWreg x)) => (MOVWZreg x)
 // normal case
-(Select0 (ANDCCconst [c] (MOV(B|BZ)reg x))) => (Select0 (ANDCCconst [c&0xFF] x))
-(Select0 (ANDCCconst [c] (MOV(H|HZ)reg x))) => (Select0 (ANDCCconst [c&0xFFFF] x))
-(Select0 (ANDCCconst [c] (MOV(W|WZ)reg x))) => (Select0 (ANDCCconst [c&0xFFFFFFFF] x))
+(Select0 (ANDCCconst [c] (MOVBZreg x))) => (Select0 (ANDCCconst [c&0xFF] x))
+(Select0 (ANDCCconst [c] (MOVHZreg x))) => (Select0 (ANDCCconst [c&0xFFFF] x))
+(Select0 (ANDCCconst [c] (MOVWZreg x))) => (Select0 (ANDCCconst [c&0xFFFFFFFF] x))
 
 // Eliminate unnecessary sign/zero extend following right shift
 (MOV(B|H|W)Zreg (SRWconst [c] (MOVBZreg x))) => (SRWconst [c] (MOVBZreg x))

src/cmd/compile/internal/ssa/expand_calls.go

@@ -855,7 +855,7 @@ func storeOneArg(x *expandState, pos src.XPos, b *Block, locs []*LocalSlot, suff
 // storeOneLoad creates a decomposed (one step) load that is then stored.
 func storeOneLoad(x *expandState, pos src.XPos, b *Block, source, mem *Value, t *types.Type, offArg, offStore int64, loadRegOffset Abi1RO, storeRc registerCursor) *Value {
 	from := x.offsetFrom(source.Block, source.Args[0], offArg, types.NewPtr(t))
-	w := source.Block.NewValue2(source.Pos, OpLoad, t, from, mem)
+	w := b.NewValue2(source.Pos, OpLoad, t, from, mem)
 	return x.storeArgOrLoad(pos, b, w, mem, t, offStore, loadRegOffset, storeRc)
 }
 
@@ -962,7 +962,7 @@ func (x *expandState) storeArgOrLoad(pos src.XPos, b *Block, source, mem *Value,
 		eltRO := x.regWidth(elt)
 		source.Type = t
 		for i := int64(0); i < t.NumElem(); i++ {
-			sel := source.Block.NewValue1I(pos, OpArraySelect, elt, i, source)
+			sel := b.NewValue1I(pos, OpArraySelect, elt, i, source)
 			mem = x.storeArgOrLoad(pos, b, sel, mem, elt, storeOffset+i*elt.Size(), loadRegOffset, storeRc.at(t, 0))
 			loadRegOffset += eltRO
 			pos = pos.WithNotStmt()
@@ -997,7 +997,7 @@ func (x *expandState) storeArgOrLoad(pos src.XPos, b *Block, source, mem *Value,
 		source.Type = t
 		for i := 0; i < t.NumFields(); i++ {
 			fld := t.Field(i)
-			sel := source.Block.NewValue1I(pos, OpStructSelect, fld.Type, int64(i), source)
+			sel := b.NewValue1I(pos, OpStructSelect, fld.Type, int64(i), source)
 			mem = x.storeArgOrLoad(pos, b, sel, mem, fld.Type, storeOffset+fld.Offset, loadRegOffset, storeRc.next(fld.Type))
 			loadRegOffset += x.regWidth(fld.Type)
 			pos = pos.WithNotStmt()
@@ -1009,48 +1009,48 @@ func (x *expandState) storeArgOrLoad(pos src.XPos, b *Block, source, mem *Value,
 			break
 		}
 		tHi, tLo := x.intPairTypes(t.Kind())
-		sel := source.Block.NewValue1(pos, OpInt64Hi, tHi, source)
+		sel := b.NewValue1(pos, OpInt64Hi, tHi, source)
 		mem = x.storeArgOrLoad(pos, b, sel, mem, tHi, storeOffset+x.hiOffset, loadRegOffset+x.hiRo, storeRc.plus(x.hiRo))
 		pos = pos.WithNotStmt()
-		sel = source.Block.NewValue1(pos, OpInt64Lo, tLo, source)
+		sel = b.NewValue1(pos, OpInt64Lo, tLo, source)
 		return x.storeArgOrLoad(pos, b, sel, mem, tLo, storeOffset+x.lowOffset, loadRegOffset+x.loRo, storeRc.plus(x.hiRo))
 
 	case types.TINTER:
-		sel := source.Block.NewValue1(pos, OpITab, x.typs.BytePtr, source)
+		sel := b.NewValue1(pos, OpITab, x.typs.BytePtr, source)
 		mem = x.storeArgOrLoad(pos, b, sel, mem, x.typs.BytePtr, storeOffset, loadRegOffset, storeRc.next(x.typs.BytePtr))
 		pos = pos.WithNotStmt()
-		sel = source.Block.NewValue1(pos, OpIData, x.typs.BytePtr, source)
+		sel = b.NewValue1(pos, OpIData, x.typs.BytePtr, source)
 		return x.storeArgOrLoad(pos, b, sel, mem, x.typs.BytePtr, storeOffset+x.ptrSize, loadRegOffset+RO_iface_data, storeRc)
 
 	case types.TSTRING:
-		sel := source.Block.NewValue1(pos, OpStringPtr, x.typs.BytePtr, source)
+		sel := b.NewValue1(pos, OpStringPtr, x.typs.BytePtr, source)
 		mem = x.storeArgOrLoad(pos, b, sel, mem, x.typs.BytePtr, storeOffset, loadRegOffset, storeRc.next(x.typs.BytePtr))
 		pos = pos.WithNotStmt()
-		sel = source.Block.NewValue1(pos, OpStringLen, x.typs.Int, source)
+		sel = b.NewValue1(pos, OpStringLen, x.typs.Int, source)
 		return x.storeArgOrLoad(pos, b, sel, mem, x.typs.Int, storeOffset+x.ptrSize, loadRegOffset+RO_string_len, storeRc)
 
 	case types.TSLICE:
 		et := types.NewPtr(t.Elem())
-		sel := source.Block.NewValue1(pos, OpSlicePtr, et, source)
+		sel := b.NewValue1(pos, OpSlicePtr, et, source)
 		mem = x.storeArgOrLoad(pos, b, sel, mem, et, storeOffset, loadRegOffset, storeRc.next(et))
 		pos = pos.WithNotStmt()
-		sel = source.Block.NewValue1(pos, OpSliceLen, x.typs.Int, source)
+		sel = b.NewValue1(pos, OpSliceLen, x.typs.Int, source)
 		mem = x.storeArgOrLoad(pos, b, sel, mem, x.typs.Int, storeOffset+x.ptrSize, loadRegOffset+RO_slice_len, storeRc.next(x.typs.Int))
-		sel = source.Block.NewValue1(pos, OpSliceCap, x.typs.Int, source)
+		sel = b.NewValue1(pos, OpSliceCap, x.typs.Int, source)
 		return x.storeArgOrLoad(pos, b, sel, mem, x.typs.Int, storeOffset+2*x.ptrSize, loadRegOffset+RO_slice_cap, storeRc)
 
 	case types.TCOMPLEX64:
-		sel := source.Block.NewValue1(pos, OpComplexReal, x.typs.Float32, source)
+		sel := b.NewValue1(pos, OpComplexReal, x.typs.Float32, source)
 		mem = x.storeArgOrLoad(pos, b, sel, mem, x.typs.Float32, storeOffset, loadRegOffset, storeRc.next(x.typs.Float32))
 		pos = pos.WithNotStmt()
-		sel = source.Block.NewValue1(pos, OpComplexImag, x.typs.Float32, source)
+		sel = b.NewValue1(pos, OpComplexImag, x.typs.Float32, source)
 		return x.storeArgOrLoad(pos, b, sel, mem, x.typs.Float32, storeOffset+4, loadRegOffset+RO_complex_imag, storeRc)
 
 	case types.TCOMPLEX128:
-		sel := source.Block.NewValue1(pos, OpComplexReal, x.typs.Float64, source)
+		sel := b.NewValue1(pos, OpComplexReal, x.typs.Float64, source)
 		mem = x.storeArgOrLoad(pos, b, sel, mem, x.typs.Float64, storeOffset, loadRegOffset, storeRc.next(x.typs.Float64))
 		pos = pos.WithNotStmt()
-		sel = source.Block.NewValue1(pos, OpComplexImag, x.typs.Float64, source)
+		sel = b.NewValue1(pos, OpComplexImag, x.typs.Float64, source)
 		return x.storeArgOrLoad(pos, b, sel, mem, x.typs.Float64, storeOffset+8, loadRegOffset+RO_complex_imag, storeRc)
 	}
 
@@ -1113,6 +1113,9 @@ func (x *expandState) rewriteArgs(v *Value, firstArg int) {
 					}
 				}
 			}
+			if x.debug > 1 {
+				x.Printf("...storeArg %s, %v, %d\n", a.LongString(), aType, aOffset)
+			}
 			// "Dereference" of addressed (probably not-SSA-eligible) value becomes Move
 			// TODO(register args) this will be more complicated with registers in the picture.
 			mem = x.rewriteDereference(v.Block, sp, a, mem, aOffset, aux.SizeOfArg(auxI), aType, v.Pos)

src/cmd/compile/internal/ssa/memcombine.go

@@ -41,6 +41,7 @@ func memcombineLoads(f *Func) {
 		}
 	}
 	for _, b := range f.Blocks {
+		order = order[:0]
 		for _, v := range b.Values {
 			if v.Op != OpOr16 && v.Op != OpOr32 && v.Op != OpOr64 {
 				continue

src/cmd/compile/internal/ssa/rewrite.go

@@ -1281,10 +1281,6 @@ func zeroUpper32Bits(x *Value, depth int) bool {
 		OpAMD64SHRL, OpAMD64SHRLconst, OpAMD64SARL, OpAMD64SARLconst,
 		OpAMD64SHLL, OpAMD64SHLLconst:
 		return true
-	case OpARM64REV16W, OpARM64REVW, OpARM64RBITW, OpARM64CLZW, OpARM64EXTRWconst,
-		OpARM64MULW, OpARM64MNEGW, OpARM64UDIVW, OpARM64DIVW, OpARM64UMODW,
-		OpARM64MADDW, OpARM64MSUBW, OpARM64RORW, OpARM64RORWconst:
-		return true
 	case OpArg:
 		return x.Type.Size() == 4
 	case OpPhi, OpSelect0, OpSelect1:

src/cmd/compile/internal/ssa/rewriteARM64.go

@@ -154,6 +154,8 @@ func rewriteValueARM64(v *Value) bool {
 		return rewriteValueARM64_OpARM64GreaterEqual(v)
 	case OpARM64GreaterEqualF:
 		return rewriteValueARM64_OpARM64GreaterEqualF(v)
+	case OpARM64GreaterEqualNoov:
+		return rewriteValueARM64_OpARM64GreaterEqualNoov(v)
 	case OpARM64GreaterEqualU:
 		return rewriteValueARM64_OpARM64GreaterEqualU(v)
 	case OpARM64GreaterThan:
@@ -174,6 +176,8 @@ func rewriteValueARM64(v *Value) bool {
 		return rewriteValueARM64_OpARM64LessThan(v)
 	case OpARM64LessThanF:
 		return rewriteValueARM64_OpARM64LessThanF(v)
+	case OpARM64LessThanNoov:
+		return rewriteValueARM64_OpARM64LessThanNoov(v)
 	case OpARM64LessThanU:
 		return rewriteValueARM64_OpARM64LessThanU(v)
 	case OpARM64MADD:
@@ -5953,6 +5957,27 @@ func rewriteValueARM64_OpARM64GreaterEqualF(v *Value) bool {
 	}
 	return false
 }
+func rewriteValueARM64_OpARM64GreaterEqualNoov(v *Value) bool {
+	v_0 := v.Args[0]
+	b := v.Block
+	typ := &b.Func.Config.Types
+	// match: (GreaterEqualNoov (InvertFlags x))
+	// result: (OR (LessThanNoov <typ.Bool> x) (Equal <typ.Bool> x))
+	for {
+		if v_0.Op != OpARM64InvertFlags {
+			break
+		}
+		x := v_0.Args[0]
+		v.reset(OpARM64OR)
+		v0 := b.NewValue0(v.Pos, OpARM64LessThanNoov, typ.Bool)
+		v0.AddArg(x)
+		v1 := b.NewValue0(v.Pos, OpARM64Equal, typ.Bool)
+		v1.AddArg(x)
+		v.AddArg2(v0, v1)
+		return true
+	}
+	return false
+}
 func rewriteValueARM64_OpARM64GreaterEqualU(v *Value) bool {
 	v_0 := v.Args[0]
 	// match: (GreaterEqualU (FlagConstant [fc]))
@@ -6667,6 +6692,27 @@ func rewriteValueARM64_OpARM64LessThanF(v *Value) bool {
 	}
 	return false
 }
+func rewriteValueARM64_OpARM64LessThanNoov(v *Value) bool {
+	v_0 := v.Args[0]
+	b := v.Block
+	typ := &b.Func.Config.Types
+	// match: (LessThanNoov (InvertFlags x))
+	// result: (BIC (GreaterEqualNoov <typ.Bool> x) (Equal <typ.Bool> x))
+	for {
+		if v_0.Op != OpARM64InvertFlags {
+			break
+		}
+		x := v_0.Args[0]
+		v.reset(OpARM64BIC)
+		v0 := b.NewValue0(v.Pos, OpARM64GreaterEqualNoov, typ.Bool)
+		v0.AddArg(x)
+		v1 := b.NewValue0(v.Pos, OpARM64Equal, typ.Bool)
+		v1.AddArg(x)
+		v.AddArg2(v0, v1)
+		return true
+	}
+	return false
+}
 func rewriteValueARM64_OpARM64LessThanU(v *Value) bool {
 	v_0 := v.Args[0]
 	// match: (LessThanU (FlagConstant [fc]))
@@ -8668,25 +8714,6 @@ func rewriteValueARM64_OpARM64MOVBreg(v *Value) bool {
 		v.AuxInt = int64ToAuxInt(int64(int8(c)))
 		return true
 	}
-	// match: (MOVBreg <t> (ANDconst x [c]))
-	// cond: uint64(c) & uint64(0xffffffffffffff80) == 0
-	// result: (ANDconst <t> x [c])
-	for {
-		t := v.Type
-		if v_0.Op != OpARM64ANDconst {
-			break
-		}
-		c := auxIntToInt64(v_0.AuxInt)
-		x := v_0.Args[0]
-		if !(uint64(c)&uint64(0xffffffffffffff80) == 0) {
-			break
-		}
-		v.reset(OpARM64ANDconst)
-		v.Type = t
-		v.AuxInt = int64ToAuxInt(c)
-		v.AddArg(x)
-		return true
-	}
 	// match: (MOVBreg (SLLconst [lc] x))
 	// cond: lc < 8
 	// result: (SBFIZ [armBFAuxInt(lc, 8-lc)] x)
@@ -10765,25 +10792,6 @@ func rewriteValueARM64_OpARM64MOVHreg(v *Value) bool {
 		v.AuxInt = int64ToAuxInt(int64(int16(c)))
 		return true
 	}
-	// match: (MOVHreg <t> (ANDconst x [c]))
-	// cond: uint64(c) & uint64(0xffffffffffff8000) == 0
-	// result: (ANDconst <t> x [c])
-	for {
-		t := v.Type
-		if v_0.Op != OpARM64ANDconst {
-			break
-		}
-		c := auxIntToInt64(v_0.AuxInt)
-		x := v_0.Args[0]
-		if !(uint64(c)&uint64(0xffffffffffff8000) == 0) {
-			break
-		}
-		v.reset(OpARM64ANDconst)
-		v.Type = t
-		v.AuxInt = int64ToAuxInt(c)
-		v.AddArg(x)
-		return true
-	}
 	// match: (MOVHreg (SLLconst [lc] x))
 	// cond: lc < 16
 	// result: (SBFIZ [armBFAuxInt(lc, 16-lc)] x)
@@ -11943,17 +11951,6 @@ func rewriteValueARM64_OpARM64MOVWUreg(v *Value) bool {
 		v.AuxInt = int64ToAuxInt(int64(uint32(c)))
 		return true
 	}
-	// match: (MOVWUreg x)
-	// cond: zeroUpper32Bits(x, 3)
-	// result: x
-	for {
-		x := v_0
-		if !(zeroUpper32Bits(x, 3)) {
-			break
-		}
-		v.copyOf(x)
-		return true
-	}
 	// match: (MOVWUreg (SLLconst [lc] x))
 	// cond: lc >= 32
 	// result: (MOVDconst [0])
@@ -12458,25 +12455,6 @@ func rewriteValueARM64_OpARM64MOVWreg(v *Value) bool {
 		v.AuxInt = int64ToAuxInt(int64(int32(c)))
 		return true
 	}
-	// match: (MOVWreg <t> (ANDconst x [c]))
-	// cond: uint64(c) & uint64(0xffffffff80000000) == 0
-	// result: (ANDconst <t> x [c])
-	for {
-		t := v.Type
-		if v_0.Op != OpARM64ANDconst {
-			break
-		}
-		c := auxIntToInt64(v_0.AuxInt)
-		x := v_0.Args[0]
-		if !(uint64(c)&uint64(0xffffffff80000000) == 0) {
-			break
-		}
-		v.reset(OpARM64ANDconst)
-		v.Type = t
-		v.AuxInt = int64ToAuxInt(c)
-		v.AddArg(x)
-		return true
-	}
 	// match: (MOVWreg (SLLconst [lc] x))
 	// cond: lc < 32
 	// result: (SBFIZ [armBFAuxInt(lc, 32-lc)] x)

src/cmd/compile/internal/ssa/rewritePPC64.go

@@ -14410,17 +14410,19 @@ func rewriteValuePPC64_OpSelect0(v *Value) bool {
 		v.copyOf(y)
 		return true
 	}
-	// match: (Select0 (ANDCCconst [0xFF] y:(MOVBreg _)))
-	// result: y
+	// match: (Select0 (ANDCCconst [0xFF] (MOVBreg x)))
+	// result: (MOVBZreg x)
 	for {
 		if v_0.Op != OpPPC64ANDCCconst || auxIntToInt64(v_0.AuxInt) != 0xFF {
 			break
 		}
-		y := v_0.Args[0]
-		if y.Op != OpPPC64MOVBreg {
+		v_0_0 := v_0.Args[0]
+		if v_0_0.Op != OpPPC64MOVBreg {
 			break
 		}
-		v.copyOf(y)
+		x := v_0_0.Args[0]
+		v.reset(OpPPC64MOVBZreg)
+		v.AddArg(x)
 		return true
 	}
 	// match: (Select0 (ANDCCconst [c] y:(MOVHZreg _)))
@@ -14438,36 +14440,19 @@ func rewriteValuePPC64_OpSelect0(v *Value) bool {
 		v.copyOf(y)
 		return true
 	}
-	// match: (Select0 (ANDCCconst [0xFFFF] y:(MOVHreg _)))
-	// result: y
+	// match: (Select0 (ANDCCconst [0xFFFF] (MOVHreg x)))
+	// result: (MOVHZreg x)
 	for {
 		if v_0.Op != OpPPC64ANDCCconst || auxIntToInt64(v_0.AuxInt) != 0xFFFF {
 			break
 		}
-		y := v_0.Args[0]
-		if y.Op != OpPPC64MOVHreg {
-			break
-		}
-		v.copyOf(y)
-		return true
-	}
-	// match: (Select0 (ANDCCconst [c] (MOVBreg x)))
-	// result: (Select0 (ANDCCconst [c&0xFF] x))
-	for {
-		if v_0.Op != OpPPC64ANDCCconst {
-			break
-		}
-		c := auxIntToInt64(v_0.AuxInt)
 		v_0_0 := v_0.Args[0]
-		if v_0_0.Op != OpPPC64MOVBreg {
+		if v_0_0.Op != OpPPC64MOVHreg {
 			break
 		}
 		x := v_0_0.Args[0]
-		v.reset(OpSelect0)
-		v0 := b.NewValue0(v.Pos, OpPPC64ANDCCconst, types.NewTuple(typ.Int, types.TypeFlags))
-		v0.AuxInt = int64ToAuxInt(c & 0xFF)
-		v0.AddArg(x)
-		v.AddArg(v0)
+		v.reset(OpPPC64MOVHZreg)
+		v.AddArg(x)
 		return true
 	}
 	// match: (Select0 (ANDCCconst [c] (MOVBZreg x)))
@@ -14489,25 +14474,6 @@ func rewriteValuePPC64_OpSelect0(v *Value) bool {
 		v.AddArg(v0)
 		return true
 	}
-	// match: (Select0 (ANDCCconst [c] (MOVHreg x)))
-	// result: (Select0 (ANDCCconst [c&0xFFFF] x))
-	for {
-		if v_0.Op != OpPPC64ANDCCconst {
-			break
-		}
-		c := auxIntToInt64(v_0.AuxInt)
-		v_0_0 := v_0.Args[0]
-		if v_0_0.Op != OpPPC64MOVHreg {
-			break
-		}
-		x := v_0_0.Args[0]
-		v.reset(OpSelect0)
-		v0 := b.NewValue0(v.Pos, OpPPC64ANDCCconst, types.NewTuple(typ.Int, types.TypeFlags))
-		v0.AuxInt = int64ToAuxInt(c & 0xFFFF)
-		v0.AddArg(x)
-		v.AddArg(v0)
-		return true
-	}
 	// match: (Select0 (ANDCCconst [c] (MOVHZreg x)))
 	// result: (Select0 (ANDCCconst [c&0xFFFF] x))
 	for {
@@ -14527,25 +14493,6 @@ func rewriteValuePPC64_OpSelect0(v *Value) bool {
 		v.AddArg(v0)
 		return true
 	}
-	// match: (Select0 (ANDCCconst [c] (MOVWreg x)))
-	// result: (Select0 (ANDCCconst [c&0xFFFFFFFF] x))
-	for {
-		if v_0.Op != OpPPC64ANDCCconst {
-			break
-		}
-		c := auxIntToInt64(v_0.AuxInt)
-		v_0_0 := v_0.Args[0]
-		if v_0_0.Op != OpPPC64MOVWreg {
-			break
-		}
-		x := v_0_0.Args[0]
-		v.reset(OpSelect0)
-		v0 := b.NewValue0(v.Pos, OpPPC64ANDCCconst, types.NewTuple(typ.Int, types.TypeFlags))
-		v0.AuxInt = int64ToAuxInt(c & 0xFFFFFFFF)
-		v0.AddArg(x)
-		v.AddArg(v0)
-		return true
-	}
 	// match: (Select0 (ANDCCconst [c] (MOVWZreg x)))
 	// result: (Select0 (ANDCCconst [c&0xFFFFFFFF] x))
 	for {

src/cmd/compile/internal/ssa/writebarrier.go

@@ -53,7 +53,10 @@ func mightContainHeapPointer(ptr *Value, size int64, mem *Value, zeroes map[ID]Z
 	}
 
 	ptrSize := ptr.Block.Func.Config.PtrSize
-	if off%ptrSize != 0 || size%ptrSize != 0 {
+	if off%ptrSize != 0 {
+		return true // see issue 61187
+	}
+	if size%ptrSize != 0 {
 		ptr.Fatalf("unaligned pointer write")
 	}
 	if off < 0 || off+size > 64*ptrSize {
@@ -130,7 +133,7 @@ func needWBdst(ptr, mem *Value, zeroes map[ID]ZeroRegion) bool {
 	}
 	ptrSize := ptr.Block.Func.Config.PtrSize
 	if off%ptrSize != 0 {
-		ptr.Fatalf("unaligned pointer write")
+		return true // see issue 61187
 	}
 	if off < 0 || off >= 64*ptrSize {
 		// write goes off end of tracked offsets

src/cmd/compile/internal/ssagen/ssa.go

@@ -7083,8 +7083,21 @@ func genssa(f *ssa.Func, pp *objw.Progs) {
 		// for an empty block this will be used for its control
 		// instruction. We won't use the actual liveness map on a
 		// control instruction. Just mark it something that is
-		// preemptible, unless this function is "all unsafe".
-		s.pp.NextLive = objw.LivenessIndex{StackMapIndex: -1, IsUnsafePoint: liveness.IsUnsafe(f)}
+		// preemptible, unless this function is "all unsafe", or
+		// the empty block is in a write barrier.
+		unsafe := liveness.IsUnsafe(f)
+		if b.Kind == ssa.BlockPlain {
+			// Empty blocks that are part of write barriers need
+			// to have their control instructions marked unsafe.
+			c := b.Succs[0].Block()
+			for _, v := range c.Values {
+				if v.Op == ssa.OpWBend {
+					unsafe = true
+					break
+				}
+			}
+		}
+		s.pp.NextLive = objw.LivenessIndex{StackMapIndex: -1, IsUnsafePoint: unsafe}
 
 		if idx, ok := argLiveBlockMap[b.ID]; ok && idx != argLiveIdx {
 			argLiveIdx = idx

src/cmd/compile/internal/types2/api.go

@@ -110,11 +110,11 @@ type Config struct {
 	// type checker will initialize this field with a newly created context.
 	Context *Context
 
-	// GoVersion describes the accepted Go language version. The string
-	// must follow the format "go%d.%d" (e.g. "go1.12") or ist must be
-	// empty; an empty string disables Go language version checks.
-	// If the format is invalid, invoking the type checker will cause a
-	// panic.
+	// GoVersion describes the accepted Go language version. The string must
+	// start with a prefix of the form "go%d.%d" (e.g. "go1.20", "go1.21rc1", or
+	// "go1.21.0") or it must be empty; an empty string disables Go language
+	// version checks. If the format is invalid, invoking the type checker will
+	// result in an error.
 	GoVersion string
 
 	// If IgnoreFuncBodies is set, function bodies are not

src/cmd/compile/internal/types2/api_test.go

@@ -2070,6 +2070,29 @@ func TestIdenticalUnions(t *testing.T) {
 	}
 }
 
+func TestIssue61737(t *testing.T) {
+	// This test verifies that it is possible to construct invalid interfaces
+	// containing duplicate methods using the go/types API.
+	//
+	// It must be possible for importers to construct such invalid interfaces.
+	// Previously, this panicked.
+
+	sig1 := NewSignatureType(nil, nil, nil, NewTuple(NewParam(nopos, nil, "", Typ[Int])), nil, false)
+	sig2 := NewSignatureType(nil, nil, nil, NewTuple(NewParam(nopos, nil, "", Typ[String])), nil, false)
+
+	methods := []*Func{
+		NewFunc(nopos, nil, "M", sig1),
+		NewFunc(nopos, nil, "M", sig2),
+	}
+
+	embeddedMethods := []*Func{
+		NewFunc(nopos, nil, "M", sig2),
+	}
+	embedded := NewInterfaceType(embeddedMethods, nil)
+	iface := NewInterfaceType(methods, []Type{embedded})
+	iface.NumMethods() // unlike go/types, there is no Complete() method, so we complete implicitly
+}
+
 func TestIssue15305(t *testing.T) {
 	const src = "package p; func f() int16; var _ = f(undef)"
 	f := mustParse(src)

src/cmd/compile/internal/types2/builtins.go

@@ -576,6 +576,11 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 		// If nargs == 1, make sure x.mode is either a value or a constant.
 		if x.mode != constant_ {
 			x.mode = value
+			// A value must not be untyped.
+			check.assignment(x, &emptyInterface, "argument to "+bin.name)
+			if x.mode == invalid {
+				return
+			}
 		}
 
 		// Use the final type computed above for all arguments.

src/cmd/compile/internal/types2/call.go

@@ -610,20 +610,17 @@ func (check *Checker) arguments(call *syntax.CallExpr, sig *Signature, targs []T
 			return // error already reported
 		}
 
-		// compute result signature: instantiate if needed
-		rsig = sig
+		// update result signature: instantiate if needed
 		if n > 0 {
 			rsig = check.instantiateSignature(call.Pos(), call.Fun, sig, targs[:n], xlist)
-		}
-
-		// Optimization: Only if the callee's parameter list was adjusted do we need to
-		// compute it from the adjusted list; otherwise we can simply use the result
-		// signature's parameter list. We only need the n type parameters and arguments
-		// of the callee.
-		if n > 0 && adjusted {
-			sigParams = check.subst(call.Pos(), sigParams, makeSubstMap(tparams[:n], targs[:n]), nil, check.context()).(*Tuple)
-		} else {
-			sigParams = rsig.params
+			// If the callee's parameter list was adjusted we need to update (instantiate)
+			// it separately. Otherwise we can simply use the result signature's parameter
+			// list.
+			if adjusted {
+				sigParams = check.subst(call.Pos(), sigParams, makeSubstMap(tparams[:n], targs[:n]), nil, check.context()).(*Tuple)
+			} else {
+				sigParams = rsig.params
+			}
 		}
 
 		// compute argument signatures: instantiate if needed

src/cmd/compile/internal/types2/const.go

@@ -73,7 +73,6 @@ func representableConst(x constant.Value, check *Checker, typ *Basic, rounded *c
 
 	sizeof := func(T Type) int64 {
 		s := conf.sizeof(T)
-		assert(s == 4 || s == 8)
 		return s
 	}
 

src/cmd/compile/internal/types2/infer.go

@@ -96,7 +96,7 @@ func (check *Checker) infer(pos syntax.Pos, tparams []*TypeParam, targs []Type,
 	// Unify parameter and argument types for generic parameters with typed arguments
 	// and collect the indices of generic parameters with untyped arguments.
 	// Terminology: generic parameter = function parameter with a type-parameterized type
-	u := newUnifier(tparams, targs)
+	u := newUnifier(tparams, targs, check.allowVersion(check.pkg, pos, go1_21))
 
 	errorf := func(kind string, tpar, targ Type, arg *operand) {
 		// provide a better error message if we can

src/cmd/compile/internal/types2/issues_test.go

@@ -900,3 +900,23 @@ func _cgoCheckResult(interface{})
 		*boolFieldAddr(cfg, "go115UsesCgo") = true
 	})
 }
+
+func TestIssue61931(t *testing.T) {
+	const src = `
+package p
+
+func A(func(any), ...any) {}
+func B[T any](T)          {}
+
+func _() {
+	A(B, nil // syntax error: missing ',' before newline in argument list
+}
+`
+	f, err := syntax.Parse(syntax.NewFileBase(pkgName(src)), strings.NewReader(src), func(error) {}, nil, 0)
+	if err == nil {
+		t.Fatal("expected syntax error")
+	}
+
+	var conf Config
+	conf.Check(f.PkgName.Value, []*syntax.File{f}, nil) // must not panic
+}

src/cmd/compile/internal/types2/typeset.go

@@ -6,7 +6,6 @@ package types2
 
 import (
 	"cmd/compile/internal/syntax"
-	"fmt"
 	. "internal/types/errors"
 	"sort"
 	"strings"
@@ -212,7 +211,6 @@ func computeInterfaceTypeSet(check *Checker, pos syntax.Pos, ityp *Interface) *_
 	// we can get rid of the mpos map below and simply use the cloned method's
 	// position.
 
-	var todo []*Func
 	var seen objset
 	var allMethods []*Func
 	mpos := make(map[*Func]syntax.Pos) // method specification or method embedding position, for good error messages
@@ -222,36 +220,30 @@ func computeInterfaceTypeSet(check *Checker, pos syntax.Pos, ityp *Interface) *_
 			allMethods = append(allMethods, m)
 			mpos[m] = pos
 		case explicit:
-			if check == nil {
-				panic(fmt.Sprintf("%s: duplicate method %s", m.pos, m.name))
+			if check != nil {
+				var err error_
+				err.code = DuplicateDecl
+				err.errorf(pos, "duplicate method %s", m.name)
+				err.errorf(mpos[other.(*Func)], "other declaration of %s", m.name)
+				check.report(&err)
 			}
-			// check != nil
-			var err error_
-			err.code = DuplicateDecl
-			err.errorf(pos, "duplicate method %s", m.name)
-			err.errorf(mpos[other.(*Func)], "other declaration of %s", m.name)
-			check.report(&err)
 		default:
 			// We have a duplicate method name in an embedded (not explicitly declared) method.
 			// Check method signatures after all types are computed (go.dev/issue/33656).
 			// If we're pre-go1.14 (overlapping embeddings are not permitted), report that
 			// error here as well (even though we could do it eagerly) because it's the same
 			// error message.
-			if check == nil {
-				// check method signatures after all locally embedded interfaces are computed
-				todo = append(todo, m, other.(*Func))
-				break
+			if check != nil {
+				check.later(func() {
+					if !check.allowVersion(m.pkg, pos, go1_14) || !Identical(m.typ, other.Type()) {
+						var err error_
+						err.code = DuplicateDecl
+						err.errorf(pos, "duplicate method %s", m.name)
+						err.errorf(mpos[other.(*Func)], "other declaration of %s", m.name)
+						check.report(&err)
+					}
+				}).describef(pos, "duplicate method check for %s", m.name)
 			}
-			// check != nil
-			check.later(func() {
-				if !check.allowVersion(m.pkg, pos, go1_14) || !Identical(m.typ, other.Type()) {
-					var err error_
-					err.code = DuplicateDecl
-					err.errorf(pos, "duplicate method %s", m.name)
-					err.errorf(mpos[other.(*Func)], "other declaration of %s", m.name)
-					check.report(&err)
-				}
-			}).describef(pos, "duplicate method check for %s", m.name)
 		}
 	}
 
@@ -314,15 +306,6 @@ func computeInterfaceTypeSet(check *Checker, pos syntax.Pos, ityp *Interface) *_
 	}
 	ityp.embedPos = nil // not needed anymore (errors have been reported)
 
-	// process todo's (this only happens if check == nil)
-	for i := 0; i < len(todo); i += 2 {
-		m := todo[i]
-		other := todo[i+1]
-		if !Identical(m.typ, other.typ) {
-			panic(fmt.Sprintf("%s: duplicate method %s", m.pos, m.name))
-		}
-	}
-
 	ityp.tset.comparable = allComparable
 	if len(allMethods) != 0 {
 		sortMethods(allMethods)

src/cmd/compile/internal/types2/unify.go

@@ -53,11 +53,6 @@ const (
 	// the core types, if any, of non-local (unbound) type parameters.
 	enableCoreTypeUnification = true
 
-	// If enableInterfaceInference is set, type inference uses
-	// shared methods for improved type inference involving
-	// interfaces.
-	enableInterfaceInference = true
-
 	// If traceInference is set, unification will print a trace of its operation.
 	// Interpretation of trace:
 	//   x ≡ y    attempt to unify types x and y
@@ -81,15 +76,16 @@ type unifier struct {
 	// that inferring the type for a given type parameter P will
 	// automatically infer the same type for all other parameters
 	// unified (joined) with P.
-	handles map[*TypeParam]*Type
-	depth   int // recursion depth during unification
+	handles                  map[*TypeParam]*Type
+	depth                    int  // recursion depth during unification
+	enableInterfaceInference bool // use shared methods for better inference
 }
 
 // newUnifier returns a new unifier initialized with the given type parameter
 // and corresponding type argument lists. The type argument list may be shorter
 // than the type parameter list, and it may contain nil types. Matching type
 // parameters and arguments must have the same index.
-func newUnifier(tparams []*TypeParam, targs []Type) *unifier {
+func newUnifier(tparams []*TypeParam, targs []Type, enableInterfaceInference bool) *unifier {
 	assert(len(tparams) >= len(targs))
 	handles := make(map[*TypeParam]*Type, len(tparams))
 	// Allocate all handles up-front: in a correct program, all type parameters
@@ -103,7 +99,7 @@ func newUnifier(tparams []*TypeParam, targs []Type) *unifier {
 		}
 		handles[x] = &t
 	}
-	return &unifier{handles, 0}
+	return &unifier{handles, 0, enableInterfaceInference}
 }
 
 // unifyMode controls the behavior of the unifier.
@@ -339,7 +335,7 @@ func (u *unifier) nify(x, y Type, mode unifyMode, p *ifacePair) (result bool) {
 	// we will fail at function instantiation or argument assignment time.
 	//
 	// If we have at least one defined type, there is one in y.
-	if ny, _ := y.(*Named); mode&exact == 0 && ny != nil && isTypeLit(x) && !(enableInterfaceInference && IsInterface(x)) {
+	if ny, _ := y.(*Named); mode&exact == 0 && ny != nil && isTypeLit(x) && !(u.enableInterfaceInference && IsInterface(x)) {
 		if traceInference {
 			u.tracef("%s ≡ under %s", x, ny)
 		}
@@ -405,18 +401,40 @@ func (u *unifier) nify(x, y Type, mode unifyMode, p *ifacePair) (result bool) {
 					// Therefore, we must fail unification (go.dev/issue/60933).
 					return false
 				}
-				// If y is a defined type, make sure we record that type
-				// for type parameter x, which may have until now only
-				// recorded an underlying type (go.dev/issue/43056).
-				// Either both types are interfaces, or neither type is.
-				// If both are interfaces, they have the same methods.
+				// If we have inexact unification and one of x or y is a defined type, select the
+				// defined type. This ensures that in a series of types, all matching against the
+				// same type parameter, we infer a defined type if there is one, independent of
+				// order. Type inference or assignment may fail, which is ok.
+				// Selecting a defined type, if any, ensures that we don't lose the type name;
+				// and since we have inexact unification, a value of equally named or matching
+				// undefined type remains assignable (go.dev/issue/43056).
 				//
-				// Note: Changing the recorded type for a type parameter to
-				// a defined type is only ok when unification is inexact.
-				// But in exact unification, if we have a match, x and y must
-				// be identical, so changing the recorded type for x is a no-op.
-				if yn {
-					u.set(px, y)
+				// Similarly, if we have inexact unification and there are no defined types but
+				// channel types, select a directed channel, if any. This ensures that in a series
+				// of unnamed types, all matching against the same type parameter, we infer the
+				// directed channel if there is one, independent of order.
+				// Selecting a directional channel, if any, ensures that a value of another
+				// inexactly unifying channel type remains assignable (go.dev/issue/62157).
+				//
+				// If we have multiple defined channel types, they are either identical or we
+				// have assignment conflicts, so we can ignore directionality in this case.
+				//
+				// If we have defined and literal channel types, a defined type wins to avoid
+				// order dependencies.
+				if mode&exact == 0 {
+					switch {
+					case xn:
+						// x is a defined type: nothing to do.
+					case yn:
+						// x is not a defined type and y is a defined type: select y.
+						u.set(px, y)
+					default:
+						// Neither x nor y are defined types.
+						if yc, _ := under(y).(*Chan); yc != nil && yc.dir != SendRecv {
+							// y is a directed channel type: select y.
+							u.set(px, y)
+						}
+					}
 				}
 				return true
 			}
@@ -437,12 +455,12 @@ func (u *unifier) nify(x, y Type, mode unifyMode, p *ifacePair) (result bool) {
 		emode |= exact
 	}
 
-	// If EnableInterfaceInference is set and we don't require exact unification,
+	// If u.EnableInterfaceInference is set and we don't require exact unification,
 	// if both types are interfaces, one interface must have a subset of the
 	// methods of the other and corresponding method signatures must unify.
 	// If only one type is an interface, all its methods must be present in the
 	// other type and corresponding method signatures must unify.
-	if enableInterfaceInference && mode&exact == 0 {
+	if u.enableInterfaceInference && mode&exact == 0 {
 		// One or both interfaces may be defined types.
 		// Look under the name, but not under type parameters (go.dev/issue/60564).
 		xi := asInterface(x)
@@ -505,7 +523,7 @@ func (u *unifier) nify(x, y Type, mode unifyMode, p *ifacePair) (result bool) {
 			}
 			// All xmethods must exist in ymethods and corresponding signatures must unify.
 			for _, xm := range xmethods {
-				if ym := ymap[xm.Id()]; ym == nil || !u.nify(xm.typ, ym.typ, emode, p) {
+				if ym := ymap[xm.Id()]; ym == nil || !u.nify(xm.typ, ym.typ, exact, p) {
 					return false
 				}
 			}
@@ -526,7 +544,7 @@ func (u *unifier) nify(x, y Type, mode unifyMode, p *ifacePair) (result bool) {
 			xmethods := xi.typeSet().methods
 			for _, xm := range xmethods {
 				obj, _, _ := LookupFieldOrMethod(y, false, xm.pkg, xm.name)
-				if ym, _ := obj.(*Func); ym == nil || !u.nify(xm.typ, ym.typ, emode, p) {
+				if ym, _ := obj.(*Func); ym == nil || !u.nify(xm.typ, ym.typ, exact, p) {
 					return false
 				}
 			}
@@ -632,7 +650,7 @@ func (u *unifier) nify(x, y Type, mode unifyMode, p *ifacePair) (result bool) {
 		}
 
 	case *Interface:
-		assert(!enableInterfaceInference || mode&exact != 0) // handled before this switch
+		assert(!u.enableInterfaceInference || mode&exact != 0) // handled before this switch
 
 		// Two interface types unify if they have the same set of methods with
 		// the same names, and corresponding function types unify.
@@ -685,7 +703,7 @@ func (u *unifier) nify(x, y Type, mode unifyMode, p *ifacePair) (result bool) {
 				}
 				for i, f := range a {
 					g := b[i]
-					if f.Id() != g.Id() || !u.nify(f.typ, g.typ, emode, q) {
+					if f.Id() != g.Id() || !u.nify(f.typ, g.typ, exact, q) {
 						return false
 					}
 				}

src/cmd/compile/internal/walk/builtin.go

@@ -135,7 +135,11 @@ func walkClear(n *ir.UnaryExpr) ir.Node {
 	typ := n.X.Type()
 	switch {
 	case typ.IsSlice():
-		return arrayClear(n.X.Pos(), n.X, nil)
+		if n := arrayClear(n.X.Pos(), n.X, nil); n != nil {
+			return n
+		}
+		// If n == nil, we are clearing an array which takes zero memory, do nothing.
+		return ir.NewBlockStmt(n.Pos(), nil)
 	case typ.IsMap():
 		return mapClear(n.X, reflectdata.TypePtrAt(n.X.Pos(), n.X.Type()))
 	}
@@ -251,7 +255,10 @@ func walkLenCap(n *ir.UnaryExpr, init *ir.Nodes) ir.Node {
 		return mkcall("countrunes", n.Type(), init, typecheck.Conv(n.X.(*ir.ConvExpr).X, types.Types[types.TSTRING]))
 	}
 	if isByteCount(n) {
-		_, len := backingArrayPtrLen(cheapExpr(n.X.(*ir.ConvExpr).X, init))
+		conv := n.X.(*ir.ConvExpr)
+		walkStmtList(conv.Init())
+		init.Append(ir.TakeInit(conv)...)
+		_, len := backingArrayPtrLen(cheapExpr(conv.X, init))
 		return len
 	}
 

src/cmd/compile/internal/walk/walk.go

@@ -278,8 +278,10 @@ func backingArrayPtrLen(n ir.Node) (ptr, length ir.Node) {
 	} else {
 		ptr.SetType(n.Type().Elem().PtrTo())
 	}
+	ptr.SetTypecheck(1)
 	length = ir.NewUnaryExpr(base.Pos, ir.OLEN, n)
 	length.SetType(types.Types[types.TINT])
+	length.SetTypecheck(1)
 	return ptr, length
 }
 

src/cmd/covdata/doc.go

@@ -3,82 +3,78 @@
 // license that can be found in the LICENSE file.
 
 /*
-//
-// Covdata is a program for manipulating and generating reports
-// from 2nd-generation coverage testing output files, those produced
-// from running applications or integration tests. E.g.
-//
-//		$ mkdir ./profiledir
-//		$ go build -cover -o myapp.exe .
-//		$ GOCOVERDIR=./profiledir ./myapp.exe <arguments>
-//		$ ls ./profiledir
-//		covcounters.cce1b350af34b6d0fb59cc1725f0ee27.821598.1663006712821344241
-//		covmeta.cce1b350af34b6d0fb59cc1725f0ee27
-//		$
-//
-// Run covdata via "go tool covdata <mode>", where 'mode' is a subcommand
-// selecting a specific reporting, merging, or data manipulation operation.
-// Descriptions on the various modes (run "go tool cover <mode> -help" for
-// specifics on usage of a given mode:
-//
-// 1. Report percent of statements covered in each profiled package
-//
-//		$ go tool covdata percent -i=profiledir
-//		cov-example/p	coverage: 41.1% of statements
-//		main	coverage: 87.5% of statements
-//      $
-//
-//
-// 2. Report import paths of packages profiled
-//
-//		$ go tool covdata pkglist -i=profiledir
-//		cov-example/p
-//		main
-//      $
-//
-// 3. Report percent statements covered by function:
-//
-//		$ go tool covdata func -i=profiledir
-//		cov-example/p/p.go:12:		emptyFn			0.0%
-//		cov-example/p/p.go:32:		Small			100.0%
-//		cov-example/p/p.go:47:		Medium			90.9%
-//      ...
-//      $
-//
-// 4. Convert coverage data to legacy textual format:
-//
-//		$ go tool covdata textfmt -i=profiledir -o=cov.txt
-//      $ head cov.txt
-//      mode: set
-//      cov-example/p/p.go:12.22,13.2 0 0
-//      cov-example/p/p.go:15.31,16.2 1 0
-//      cov-example/p/p.go:16.3,18.3 0 0
-//      cov-example/p/p.go:19.3,21.3 0 0
-//      ...
-//      $ go tool cover -html=cov.txt
-//      $
-//
-// 5. Merge profiles together:
-//
-//		$ go tool covdata merge -i=indir1,indir2 -o=outdir -modpaths=github.com/go-delve/delve
-//      $
-//
-// 6. Subtract one profile from another
-//
-//		$ go tool covdata subtract -i=indir1,indir2 -o=outdir
-//      $
-//
-// 7. Intersect profiles
-//
-//		$ go tool covdata intersect -i=indir1,indir2 -o=outdir
-//      $
-//
-// 8. Dump a profile for debugging purposes.
-//
-//		$ go tool covdata debugdump -i=indir
-//      <human readable output>
-//      $
-//
-*/
+Covdata is a program for manipulating and generating reports
+from 2nd-generation coverage testing output files, those produced
+from running applications or integration tests. E.g.
 
+	$ mkdir ./profiledir
+	$ go build -cover -o myapp.exe .
+	$ GOCOVERDIR=./profiledir ./myapp.exe <arguments>
+	$ ls ./profiledir
+	covcounters.cce1b350af34b6d0fb59cc1725f0ee27.821598.1663006712821344241
+	covmeta.cce1b350af34b6d0fb59cc1725f0ee27
+	$
+
+Run covdata via "go tool covdata <mode>", where 'mode' is a subcommand
+selecting a specific reporting, merging, or data manipulation operation.
+Descriptions on the various modes (run "go tool cover <mode> -help" for
+specifics on usage of a given mode:
+
+1. Report percent of statements covered in each profiled package
+
+	$ go tool covdata percent -i=profiledir
+	cov-example/p	coverage: 41.1% of statements
+	main	coverage: 87.5% of statements
+	$
+
+2. Report import paths of packages profiled
+
+	$ go tool covdata pkglist -i=profiledir
+	cov-example/p
+	main
+	$
+
+3. Report percent statements covered by function:
+
+	$ go tool covdata func -i=profiledir
+	cov-example/p/p.go:12:		emptyFn			0.0%
+	cov-example/p/p.go:32:		Small			100.0%
+	cov-example/p/p.go:47:		Medium			90.9%
+	...
+	$
+
+4. Convert coverage data to legacy textual format:
+
+	$ go tool covdata textfmt -i=profiledir -o=cov.txt
+	$ head cov.txt
+	mode: set
+	cov-example/p/p.go:12.22,13.2 0 0
+	cov-example/p/p.go:15.31,16.2 1 0
+	cov-example/p/p.go:16.3,18.3 0 0
+	cov-example/p/p.go:19.3,21.3 0 0
+	...
+	$ go tool cover -html=cov.txt
+	$
+
+5. Merge profiles together:
+
+	$ go tool covdata merge -i=indir1,indir2 -o=outdir -modpaths=github.com/go-delve/delve
+	$
+
+6. Subtract one profile from another
+
+	$ go tool covdata subtract -i=indir1,indir2 -o=outdir
+	$
+
+7. Intersect profiles
+
+	$ go tool covdata intersect -i=indir1,indir2 -o=outdir
+	$
+
+8. Dump a profile for debugging purposes.
+
+	$ go tool covdata debugdump -i=indir
+	<human readable output>
+	$
+*/
 package main

src/cmd/dist/test.go

@@ -91,6 +91,29 @@ type work struct {
 	end   chan bool
 }
 
+// printSkip prints a skip message for all of work.
+func (w *work) printSkip(t *tester, msg string) {
+	if t.json {
+		type event struct {
+			Time    time.Time
+			Action  string
+			Package string
+			Output  string `json:",omitempty"`
+		}
+		enc := json.NewEncoder(&w.out)
+		ev := event{Time: time.Now(), Package: w.dt.name, Action: "start"}
+		enc.Encode(ev)
+		ev.Action = "output"
+		ev.Output = msg
+		enc.Encode(ev)
+		ev.Action = "skip"
+		ev.Output = ""
+		enc.Encode(ev)
+		return
+	}
+	fmt.Fprintln(&w.out, msg)
+}
+
 // A distTest is a test run by dist test.
 // Each test has a unique name and belongs to a group (heading)
 type distTest struct {
@@ -405,6 +428,9 @@ func (opts *goTest) buildArgs(t *tester) (build, run, pkgs, testFlags []string,
 	if opts.timeout != 0 {
 		d := opts.timeout * time.Duration(t.timeoutScale)
 		run = append(run, "-timeout="+d.String())
+	} else if t.timeoutScale != 1 {
+		const goTestDefaultTimeout = 10 * time.Minute // Default value of go test -timeout flag.
+		run = append(run, "-timeout="+(goTestDefaultTimeout*time.Duration(t.timeoutScale)).String())
 	}
 	if opts.short || t.short {
 		run = append(run, "-short")
@@ -1235,7 +1261,7 @@ func (t *tester) runPending(nextTest *distTest) {
 		go func(w *work) {
 			if !<-w.start {
 				timelog("skip", w.dt.name)
-				w.out.WriteString("skipped due to earlier error\n")
+				w.printSkip(t, "skipped due to earlier error")
 			} else {
 				timelog("start", w.dt.name)
 				w.err = w.cmd.Run()
@@ -1246,7 +1272,7 @@ func (t *tester) runPending(nextTest *distTest) {
 					if isUnsupportedVMASize(w) {
 						timelog("skip", w.dt.name)
 						w.out.Reset()
-						w.out.WriteString("skipped due to unsupported VMA\n")
+						w.printSkip(t, "skipped due to unsupported VMA")
 						w.err = nil
 					}
 				}

src/cmd/distpack/archive.go

@@ -44,7 +44,7 @@ type fileInfo struct {
 func (i fileInfo) Name() string       { return path.Base(i.f.Name) }
 func (i fileInfo) ModTime() time.Time { return i.f.Time }
 func (i fileInfo) Mode() fs.FileMode  { return i.f.Mode }
-func (i fileInfo) IsDir() bool        { return false }
+func (i fileInfo) IsDir() bool        { return i.f.Mode&fs.ModeDir != 0 }
 func (i fileInfo) Size() int64        { return i.f.Size }
 func (i fileInfo) Sys() any           { return nil }
 

src/cmd/distpack/pack.go

@@ -329,8 +329,47 @@ func writeTgz(name string, a *Archive) {
 
 	zw := check(gzip.NewWriterLevel(out, gzip.BestCompression))
 	tw := tar.NewWriter(zw)
+
+	// Find the mode and mtime to use for directory entries,
+	// based on the mode and mtime of the first file we see.
+	// We know that modes and mtimes are uniform across the archive.
+	var dirMode fs.FileMode
+	var mtime time.Time
+	for _, f := range a.Files {
+		dirMode = fs.ModeDir | f.Mode | (f.Mode&0444)>>2 // copy r bits down to x bits
+		mtime = f.Time
+		break
+	}
+
+	// mkdirAll ensures that the tar file contains directory
+	// entries for dir and all its parents. Some programs reading
+	// these tar files expect that. See go.dev/issue/61862.
+	haveDir := map[string]bool{".": true}
+	var mkdirAll func(string)
+	mkdirAll = func(dir string) {
+		if dir == "/" {
+			panic("mkdirAll /")
+		}
+		if haveDir[dir] {
+			return
+		}
+		haveDir[dir] = true
+		mkdirAll(path.Dir(dir))
+		df := &File{
+			Name: dir + "/",
+			Time: mtime,
+			Mode: dirMode,
+		}
+		h := check(tar.FileInfoHeader(df.Info(), ""))
+		h.Name = dir + "/"
+		if err := tw.WriteHeader(h); err != nil {
+			panic(err)
+		}
+	}
+
 	for _, f = range a.Files {
 		h := check(tar.FileInfoHeader(f.Info(), ""))
+		mkdirAll(path.Dir(f.Name))
 		h.Name = f.Name
 		if err := tw.WriteHeader(h); err != nil {
 			panic(err)

src/cmd/go.mod

@@ -4,12 +4,12 @@ go 1.21
 
 require (
 	github.com/google/pprof v0.0.0-20221118152302-e6195bd50e26
-	golang.org/x/arch v0.3.0
-	golang.org/x/mod v0.10.1-0.20230606122920-62c7e578f1a7
-	golang.org/x/sync v0.2.1-0.20230601203510-93782cc822b6
-	golang.org/x/sys v0.9.0
-	golang.org/x/term v0.9.0
-	golang.org/x/tools v0.9.4-0.20230613194514-c6c983054920
+	golang.org/x/arch v0.4.0
+	golang.org/x/mod v0.12.0
+	golang.org/x/sync v0.3.0
+	golang.org/x/sys v0.10.0
+	golang.org/x/term v0.10.0
+	golang.org/x/tools v0.11.1-0.20230712164437-1ca21856af7b
 )
 
 require github.com/ianlancetaylor/demangle v0.0.0-20220319035150-800ac71e25c2 // indirect

src/cmd/go.sum

@@ -2,15 +2,15 @@ github.com/google/pprof v0.0.0-20221118152302-e6195bd50e26 h1:Xim43kblpZXfIBQsbu
 github.com/google/pprof v0.0.0-20221118152302-e6195bd50e26/go.mod h1:dDKJzRmX4S37WGHujM7tX//fmj1uioxKzKxz3lo4HJo=
 github.com/ianlancetaylor/demangle v0.0.0-20220319035150-800ac71e25c2 h1:rcanfLhLDA8nozr/K289V1zcntHr3V+SHlXwzz1ZI2g=
 github.com/ianlancetaylor/demangle v0.0.0-20220319035150-800ac71e25c2/go.mod h1:aYm2/VgdVmcIU8iMfdMvDMsRAQjcfZSKFby6HOFvi/w=
-golang.org/x/arch v0.3.0 h1:02VY4/ZcO/gBOH6PUaoiptASxtXU10jazRCP865E97k=
-golang.org/x/arch v0.3.0/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
-golang.org/x/mod v0.10.1-0.20230606122920-62c7e578f1a7 h1:OSEstGpBW1+G0wiXI0bBgOnI8nRJQKX3GCNxF75VR1s=
-golang.org/x/mod v0.10.1-0.20230606122920-62c7e578f1a7/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
-golang.org/x/sync v0.2.1-0.20230601203510-93782cc822b6 h1:kiysxTbHE5FVnrNyc9BC/yeJi3DTUBHIJtNbC9uvXk4=
-golang.org/x/sync v0.2.1-0.20230601203510-93782cc822b6/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
-golang.org/x/sys v0.9.0 h1:KS/R3tvhPqvJvwcKfnBHJwwthS11LRhmM5D59eEXa0s=
-golang.org/x/sys v0.9.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/term v0.9.0 h1:GRRCnKYhdQrD8kfRAdQ6Zcw1P0OcELxGLKJvtjVMZ28=
-golang.org/x/term v0.9.0/go.mod h1:M6DEAAIenWoTxdKrOltXcmDY3rSplQUkrvaDU5FcQyo=
-golang.org/x/tools v0.9.4-0.20230613194514-c6c983054920 h1:FJIPEU9owLOeJgghpx63YhobtkWkORJ3O5ZnbFr8Bzs=
-golang.org/x/tools v0.9.4-0.20230613194514-c6c983054920/go.mod h1:owI94Op576fPu3cIGQeHs3joujW/2Oc6MtlxbF5dfNc=
+golang.org/x/arch v0.4.0 h1:A8WCeEWhLwPBKNbFi5Wv5UTCBx5zzubnXDlMOFAzFMc=
+golang.org/x/arch v0.4.0/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
+golang.org/x/mod v0.12.0 h1:rmsUpXtvNzj340zd98LZ4KntptpfRHwpFOHG188oHXc=
+golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
+golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
+golang.org/x/sys v0.10.0 h1:SqMFp9UcQJZa+pmYuAKjd9xq1f0j5rLcDIk0mj4qAsA=
+golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.10.0 h1:3R7pNqamzBraeqj/Tj8qt1aQ2HpmlC+Cx/qL/7hn4/c=
+golang.org/x/term v0.10.0/go.mod h1:lpqdcUyK/oCiQxvxVrppt5ggO2KCZ5QblwqPnfZ6d5o=
+golang.org/x/tools v0.11.1-0.20230712164437-1ca21856af7b h1:KIZCni6lCdxd4gxHx49Zp9mhckTFRbI/ZPDbR3jKu90=
+golang.org/x/tools v0.11.1-0.20230712164437-1ca21856af7b/go.mod h1:anzJrxPjNtfgiYQYirP2CPGzGLxrH2u2QBhn6Bf3qY8=

src/cmd/go/internal/cfg/cfg.go

@@ -490,25 +490,43 @@ func findGOROOT(env string) string {
 		// depend on the executable's location.
 		return def
 	}
+
+	// canonical returns a directory path that represents
+	// the same directory as dir,
+	// preferring the spelling in def if the two are the same.
+	canonical := func(dir string) string {
+		if isSameDir(def, dir) {
+			return def
+		}
+		return dir
+	}
+
 	exe, err := os.Executable()
 	if err == nil {
 		exe, err = filepath.Abs(exe)
 		if err == nil {
+			// cmd/go may be installed in GOROOT/bin or GOROOT/bin/GOOS_GOARCH,
+			// depending on whether it was cross-compiled with a different
+			// GOHOSTOS (see https://go.dev/issue/62119). Try both.
 			if dir := filepath.Join(exe, "../.."); isGOROOT(dir) {
-				// If def (runtime.GOROOT()) and dir are the same
-				// directory, prefer the spelling used in def.
-				if isSameDir(def, dir) {
-					return def
-				}
-				return dir
+				return canonical(dir)
 			}
+			if dir := filepath.Join(exe, "../../.."); isGOROOT(dir) {
+				return canonical(dir)
+			}
+
+			// Depending on what was passed on the command line, it is possible
+			// that os.Executable is a symlink (like /usr/local/bin/go) referring
+			// to a binary installed in a real GOROOT elsewhere
+			// (like /usr/lib/go/bin/go).
+			// Try to find that GOROOT by resolving the symlinks.
 			exe, err = filepath.EvalSymlinks(exe)
 			if err == nil {
 				if dir := filepath.Join(exe, "../.."); isGOROOT(dir) {
-					if isSameDir(def, dir) {
-						return def
-					}
-					return dir
+					return canonical(dir)
+				}
+				if dir := filepath.Join(exe, "../../.."); isGOROOT(dir) {
+					return canonical(dir)
 				}
 			}
 		}

src/cmd/go/internal/gover/gover.go

@@ -179,6 +179,9 @@ func parse(x string) version {
 	// Parse prerelease.
 	i := 0
 	for i < len(x) && (x[i] < '0' || '9' < x[i]) {
+		if x[i] < 'a' || 'z' < x[i] {
+			return version{}
+		}
 		i++
 	}
 	if i == 0 {

src/cmd/go/internal/gover/gover_test.go

@@ -95,6 +95,25 @@ var prevTests = []testCase1[string, string]{
 	{"1.40000000000000000", "1.39999999999999999"},
 }
 
+func TestIsValid(t *testing.T) { test1(t, isValidTests, "IsValid", IsValid) }
+
+var isValidTests = []testCase1[string, bool]{
+	{"1.2rc3", true},
+	{"1.2.3", true},
+	{"1.999testmod", true},
+	{"1.600+auto", false},
+	{"1.22", true},
+	{"1.21.0", true},
+	{"1.21rc2", true},
+	{"1.21", true},
+	{"1.20.0", true},
+	{"1.20", true},
+	{"1.19", true},
+	{"1.3", true},
+	{"1.2", true},
+	{"1", true},
+}
+
 type testCase1[In, Out any] struct {
 	in  In
 	out Out

src/cmd/go/internal/gover/toolchain.go

@@ -15,13 +15,20 @@ import (
 // FromToolchain returns the Go version for the named toolchain,
 // derived from the name itself (not by running the toolchain).
 // A toolchain is named "goVERSION".
-// A suffix after the VERSION introduced by a +, -, space, or tab is removed.
+// A suffix after the VERSION introduced by a -, space, or tab is removed.
 // Examples:
 //
 //	FromToolchain("go1.2.3") == "1.2.3"
 //	FromToolchain("go1.2.3-bigcorp") == "1.2.3"
 //	FromToolchain("invalid") == ""
 func FromToolchain(name string) string {
+	if strings.ContainsAny(name, "\\/") {
+		// The suffix must not include a path separator, since that would cause
+		// exec.LookPath to resolve it from a relative directory instead of from
+		// $PATH.
+		return ""
+	}
+
 	var v string
 	if strings.HasPrefix(name, "go") {
 		v = name[2:]

src/cmd/go/internal/list/list.go

@@ -959,7 +959,10 @@ func collectDepsErrors(p *load.Package) {
 			if len(stkj) != 0 {
 				return true
 			}
+
 			return p.DepsErrors[i].Err.Error() < p.DepsErrors[j].Err.Error()
+		} else if len(stkj) == 0 {
+			return false
 		}
 		pathi, pathj := stki[len(stki)-1], stkj[len(stkj)-1]
 		return pathi < pathj

src/cmd/go/internal/load/test.go

@@ -473,6 +473,7 @@ func recompileForTest(pmain, preal, ptest, pxtest *Package) *PackageError {
 			p.Target = ""
 			p.Internal.BuildInfo = nil
 			p.Internal.ForceLibrary = true
+			p.Internal.PGOProfile = preal.Internal.PGOProfile
 		}
 
 		// Update p.Internal.Imports to use test copies.
@@ -496,6 +497,11 @@ func recompileForTest(pmain, preal, ptest, pxtest *Package) *PackageError {
 		if p.Name == "main" && p != pmain && p != ptest {
 			split()
 		}
+		// Split and attach PGO information to test dependencies if preal
+		// is built with PGO.
+		if preal.Internal.PGOProfile != "" && p.Internal.PGOProfile == "" {
+			split()
+		}
 	}
 
 	// Do search to find cycle.

src/cmd/go/internal/modfetch/toolchain.go

@@ -60,6 +60,15 @@ func (r *toolchainRepo) Versions(ctx context.Context, prefix string) (*Versions,
 		}
 	}
 
+	// Always include our own version.
+	// This means that the development branch of Go 1.21 (say) will allow 'go get go@1.21'
+	// even though there are no Go 1.21 releases yet.
+	// Once there is a release, 1.21 will be treated as a query matching the latest available release.
+	// Before then, 1.21 will be treated as a query that resolves to this entry we are adding (1.21).
+	if v := gover.Local(); !have[v] {
+		list = append(list, goPrefix+v)
+	}
+
 	if r.path == "go" {
 		sort.Slice(list, func(i, j int) bool {
 			return gover.Compare(list[i], list[j]) < 0
@@ -74,21 +83,38 @@ func (r *toolchainRepo) Versions(ctx context.Context, prefix string) (*Versions,
 }
 
 func (r *toolchainRepo) Stat(ctx context.Context, rev string) (*RevInfo, error) {
-	// If we're asking about "go" (not "toolchain"), pretend to have
-	// all earlier Go versions available without network access:
-	// we will provide those ourselves, at least in GOTOOLCHAIN=auto mode.
-	if r.path == "go" && gover.Compare(rev, gover.Local()) <= 0 {
-		return &RevInfo{Version: rev}, nil
-	}
-
 	// Convert rev to DL version and stat that to make sure it exists.
+	// In theory the go@ versions should be like 1.21.0
+	// and the toolchain@ versions should be like go1.21.0
+	// but people will type the wrong one, and so we accept
+	// both and silently correct it to the standard form.
 	prefix := ""
 	v := rev
 	v = strings.TrimPrefix(v, "go")
 	if r.path == "toolchain" {
 		prefix = "go"
 	}
+
+	if !gover.IsValid(v) {
+		return nil, fmt.Errorf("invalid %s version %s", r.path, rev)
+	}
+
+	// If we're asking about "go" (not "toolchain"), pretend to have
+	// all earlier Go versions available without network access:
+	// we will provide those ourselves, at least in GOTOOLCHAIN=auto mode.
+	if r.path == "go" && gover.Compare(v, gover.Local()) <= 0 {
+		return &RevInfo{Version: prefix + v}, nil
+	}
+
+	// Similarly, if we're asking about *exactly* the current toolchain,
+	// we don't need to access the network to know that it exists.
+	if r.path == "toolchain" && v == gover.Local() {
+		return &RevInfo{Version: prefix + v}, nil
+	}
+
 	if gover.IsLang(v) {
+		// We can only use a language (development) version if the current toolchain
+		// implements that version, and the two checks above have ruled that out.
 		return nil, fmt.Errorf("go language version %s is not a toolchain version", rev)
 	}
 

src/cmd/go/internal/modget/query.go

@@ -239,10 +239,13 @@ func (q *query) matchesPath(path string) bool {
 // canMatchInModule reports whether the given module path can potentially
 // contain q.pattern.
 func (q *query) canMatchInModule(mPath string) bool {
+	if gover.IsToolchain(mPath) {
+		return false
+	}
 	if q.canMatchWildcardInModule != nil {
 		return q.canMatchWildcardInModule(mPath)
 	}
-	return str.HasPathPrefix(q.pattern, mPath) && !gover.IsToolchain(mPath)
+	return str.HasPathPrefix(q.pattern, mPath)
 }
 
 // pathOnce invokes f to generate the pathSet for the given path,

src/cmd/go/internal/modload/list.go

@@ -110,7 +110,13 @@ func ListModules(ctx context.Context, args []string, mode ListMode, reuseFile st
 
 	if err == nil {
 		requirements = rs
-		if !ExplicitWriteGoMod {
+		// TODO(#61605): The extra ListU clause fixes a problem with Go 1.21rc3
+		// where "go mod tidy" and "go list -m -u all" fight over whether the go.sum
+		// should be considered up-to-date. The fix for now is to always treat the
+		// go.sum as up-to-date during list -m -u. Probably the right fix is more targeted,
+		// but in general list -u is looking up other checksums in the checksum database
+		// that won't be necessary later, so it makes sense not to write the go.sum back out.
+		if !ExplicitWriteGoMod && mode&ListU == 0 {
 			err = commitRequirements(ctx, WriteOpts{})
 		}
 	}

src/cmd/go/internal/modload/query.go

@@ -473,7 +473,11 @@ func newQueryMatcher(path string, query, current string, allowed AllowedFunc) (*
 // AllowedFunc of qm.
 func (qm *queryMatcher) allowsVersion(ctx context.Context, v string) bool {
 	if qm.prefix != "" && !strings.HasPrefix(v, qm.prefix) {
-		return false
+		if gover.IsToolchain(qm.path) && strings.TrimSuffix(qm.prefix, ".") == v {
+			// Allow 1.21 to match "1.21." prefix.
+		} else {
+			return false
+		}
 	}
 	if qm.filter != nil && !qm.filter(v) {
 		return false

src/cmd/go/internal/test/test.go

@@ -1363,65 +1363,87 @@ func (r *runTestActor) Act(b *work.Builder, ctx context.Context, a *work.Action)
 	ctx, cancel := context.WithTimeout(ctx, testKillTimeout)
 	defer cancel()
 
-	cmd := exec.CommandContext(ctx, args[0], args[1:]...)
-	cmd.Dir = a.Package.Dir
-
-	env := slices.Clip(cfg.OrigEnv)
-	env = base.AppendPATH(env)
-	env = base.AppendPWD(env, cmd.Dir)
-	cmd.Env = env
-	if addToEnv != "" {
-		cmd.Env = append(cmd.Env, addToEnv)
-	}
-
-	cmd.Stdout = stdout
-	cmd.Stderr = stdout
-
-	// If there are any local SWIG dependencies, we want to load
-	// the shared library from the build directory.
-	if a.Package.UsesSwig() {
-		env := cmd.Env
-		found := false
-		prefix := "LD_LIBRARY_PATH="
-		for i, v := range env {
-			if strings.HasPrefix(v, prefix) {
-				env[i] = v + ":."
-				found = true
-				break
-			}
-		}
-		if !found {
-			env = append(env, "LD_LIBRARY_PATH=.")
-		}
-		cmd.Env = env
-	}
+	// Now we're ready to actually run the command.
+	//
+	// If the -o flag is set, or if at some point we change cmd/go to start
+	// copying test executables into the build cache, we may run into spurious
+	// ETXTBSY errors on Unix platforms (see https://go.dev/issue/22315).
+	//
+	// Since we know what causes those, and we know that they should resolve
+	// quickly (the ETXTBSY error will resolve as soon as the subprocess
+	// holding the descriptor open reaches its 'exec' call), we retry them
+	// in a loop.
 
 	var (
+		cmd            *exec.Cmd
+		t0             time.Time
 		cancelKilled   = false
 		cancelSignaled = false
 	)
-	cmd.Cancel = func() error {
-		if base.SignalTrace == nil {
-			err := cmd.Process.Kill()
+	for {
+		cmd = exec.CommandContext(ctx, args[0], args[1:]...)
+		cmd.Dir = a.Package.Dir
+
+		env := slices.Clip(cfg.OrigEnv)
+		env = base.AppendPATH(env)
+		env = base.AppendPWD(env, cmd.Dir)
+		cmd.Env = env
+		if addToEnv != "" {
+			cmd.Env = append(cmd.Env, addToEnv)
+		}
+
+		cmd.Stdout = stdout
+		cmd.Stderr = stdout
+
+		// If there are any local SWIG dependencies, we want to load
+		// the shared library from the build directory.
+		if a.Package.UsesSwig() {
+			env := cmd.Env
+			found := false
+			prefix := "LD_LIBRARY_PATH="
+			for i, v := range env {
+				if strings.HasPrefix(v, prefix) {
+					env[i] = v + ":."
+					found = true
+					break
+				}
+			}
+			if !found {
+				env = append(env, "LD_LIBRARY_PATH=.")
+			}
+			cmd.Env = env
+		}
+
+		cmd.Cancel = func() error {
+			if base.SignalTrace == nil {
+				err := cmd.Process.Kill()
+				if err == nil {
+					cancelKilled = true
+				}
+				return err
+			}
+
+			// Send a quit signal in the hope that the program will print
+			// a stack trace and exit.
+			err := cmd.Process.Signal(base.SignalTrace)
 			if err == nil {
-				cancelKilled = true
+				cancelSignaled = true
 			}
 			return err
 		}
+		cmd.WaitDelay = testWaitDelay
 
-		// Send a quit signal in the hope that the program will print
-		// a stack trace and exit.
-		err := cmd.Process.Signal(base.SignalTrace)
-		if err == nil {
-			cancelSignaled = true
+		base.StartSigHandlers()
+		t0 = time.Now()
+		err = cmd.Run()
+
+		if !isETXTBSY(err) {
+			// We didn't hit the race in #22315, so there is no reason to retry the
+			// command.
+			break
 		}
-		return err
 	}
-	cmd.WaitDelay = testWaitDelay
 
-	base.StartSigHandlers()
-	t0 := time.Now()
-	err = cmd.Run()
 	out := buf.Bytes()
 	a.TestOutput = &buf
 	t := fmt.Sprintf("%.3fs", time.Since(t0).Seconds())

src/cmd/go/internal/test/test_nonunix.go

@@ -0,0 +1,12 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !unix
+
+package test
+
+func isETXTBSY(err error) bool {
+	// syscall.ETXTBSY is only meaningful on Unix platforms.
+	return false
+}

src/cmd/go/internal/test/test_unix.go

@@ -0,0 +1,16 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix
+
+package test
+
+import (
+	"errors"
+	"syscall"
+)
+
+func isETXTBSY(err error) bool {
+	return errors.Is(err, syscall.ETXTBSY)
+}

src/cmd/go/internal/test/testflag.go

@@ -61,7 +61,7 @@ func init() {
 	cf.String("run", "", "")
 	cf.Bool("short", false, "")
 	cf.String("skip", "", "")
-	cf.DurationVar(&testTimeout, "timeout", 10*time.Minute, "")
+	cf.DurationVar(&testTimeout, "timeout", 10*time.Minute, "") // known to cmd/dist
 	cf.String("fuzztime", "", "")
 	cf.String("fuzzminimizetime", "", "")
 	cf.StringVar(&testTrace, "trace", "", "")

src/cmd/go/internal/toolchain/select.go

@@ -131,7 +131,7 @@ func Select() {
 	} else {
 		min, suffix, plus := strings.Cut(gotoolchain, "+") // go1.2.3+auto
 		if min != "local" {
-			v := gover.FromToolchain(gotoolchain)
+			v := gover.FromToolchain(min)
 			if v == "" {
 				if plus {
 					base.Fatalf("invalid GOTOOLCHAIN %q: invalid minimum toolchain %q", gotoolchain, min)

src/cmd/go/internal/web/http.go

@@ -212,16 +212,22 @@ func get(security SecurityMode, url *urlpkg.URL) (*Response, error) {
 			}
 		}
 
-		if res == nil || res.Body == nil {
+		if err != nil {
+			// Per the docs for [net/http.Client.Do], “On error, any Response can be
+			// ignored. A non-nil Response with a non-nil error only occurs when
+			// CheckRedirect fails, and even then the returned Response.Body is
+			// already closed.”
 			release()
-		} else {
-			body := res.Body
-			res.Body = hookCloser{
-				ReadCloser: body,
-				afterClose: release,
-			}
+			return nil, nil, err
 		}
 
+		// “If the returned error is nil, the Response will contain a non-nil Body
+		// which the user is expected to close.”
+		body := res.Body
+		res.Body = hookCloser{
+			ReadCloser: body,
+			afterClose: release,
+		}
 		return url, res, err
 	}
 

src/cmd/go/main.go

@@ -175,7 +175,11 @@ func main() {
 		if used > 0 {
 			helpArg += " " + strings.Join(args[:used], " ")
 		}
-		fmt.Fprintf(os.Stderr, "go %s: unknown command\nRun 'go help%s' for usage.\n", cfg.CmdName, helpArg)
+		cmdName := cfg.CmdName
+		if cmdName == "" {
+			cmdName = args[0]
+		}
+		fmt.Fprintf(os.Stderr, "go %s: unknown command\nRun 'go help%s' for usage.\n", cmdName, helpArg)
 		base.SetExitStatus(2)
 		base.Exit()
 	}

src/cmd/go/scriptconds_test.go

@@ -49,6 +49,7 @@ func scriptConditions() map[string]script.Cond {
 	add("git", lazyBool("the 'git' executable exists and provides the standard CLI", hasWorkingGit))
 	add("GODEBUG", script.PrefixCondition("GODEBUG contains <suffix>", hasGodebug))
 	add("GOEXPERIMENT", script.PrefixCondition("GOEXPERIMENT <suffix> is enabled", hasGoexperiment))
+	add("go-builder", script.BoolCondition("GO_BUILDER_NAME is non-empty", testenv.Builder() != ""))
 	add("link", lazyBool("testenv.HasLink()", testenv.HasLink))
 	add("mismatched-goroot", script.Condition("test's GOROOT_FINAL does not match the real GOROOT", isMismatchedGoroot))
 	add("msan", sysCondition("-msan", platform.MSanSupported, true))

src/cmd/go/testdata/script/README

@@ -398,6 +398,8 @@ The available conditions are:
 	GOOS/GOARCH supports -fuzz with instrumentation
 [git]
 	the 'git' executable exists and provides the standard CLI
+[go-builder]
+	GO_BUILDER_NAME is non-empty
 [link]
 	testenv.HasLink()
 [mismatched-goroot]

src/cmd/go/testdata/script/build_pgo_auto_multi.txt

@@ -45,6 +45,12 @@ stderr 'compile.*-pgoprofile=.*b(/|\\\\)default\.pgo.*b(/|\\\\)b_test\.go'
 stderr 'compile.*-pgoprofile=.*b(/|\\\\)default\.pgo.*dep(/|\\\\)dep\.go'
 ! stderr 'compile.*-pgoprofile=.*nopgo(/|\\\\)nopgo_test\.go'
 
+# test-only dependencies also have profiles attached
+stderr 'compile.*-pgoprofile=.*a(/|\\\\)default\.pgo.*testdep(/|\\\\)testdep\.go'
+stderr 'compile.*-pgoprofile=.*b(/|\\\\)default\.pgo.*testdep(/|\\\\)testdep\.go'
+stderr 'compile.*-pgoprofile=.*a(/|\\\\)default\.pgo.*testdep2(/|\\\\)testdep2\.go'
+stderr 'compile.*-pgoprofile=.*b(/|\\\\)default\.pgo.*testdep2(/|\\\\)testdep2\.go'
+
 # go list -deps prints packages built multiple times.
 go list -pgo=auto -deps ./a ./b ./nopgo
 stdout 'test/dep \[test/a\]'
@@ -66,6 +72,7 @@ func main() {}
 -- a/a_test.go --
 package main
 import "testing"
+import _ "test/testdep"
 func TestA(*testing.T) {}
 -- a/default.pgo --
 -- b/b.go --
@@ -76,6 +83,7 @@ func main() {}
 -- b/b_test.go --
 package main
 import "testing"
+import _ "test/testdep"
 func TestB(*testing.T) {}
 -- b/default.pgo --
 -- nopgo/nopgo.go --
@@ -94,3 +102,8 @@ import _ "test/dep3"
 package dep2
 -- dep3/dep3.go --
 package dep3
+-- testdep/testdep.go --
+package testdep
+import _ "test/testdep2"
+-- testdep2/testdep2.go --
+package testdep2

src/cmd/go/testdata/script/go_badcmd.txt

@@ -0,0 +1,2 @@
+! go asdf
+stderr '^go asdf: unknown command'

src/cmd/go/testdata/script/goroot_executable.txt

@@ -1,4 +1,5 @@
 [compiler:gccgo] skip
+[short] skip 'builds and links another cmd/go'
 
 mkdir $WORK/new/bin
 
@@ -9,15 +10,18 @@ mkdir $WORK/new/bin
 # new cmd/go is built.
 env GOROOT_FINAL=
 
+# $GOROOT/bin/go is whatever the user has already installed
+# (using make.bash or similar). We can't make assumptions about what
+# options it may have been built with, such as -trimpath or GOROOT_FINAL.
+# Instead, we build a fresh copy of the binary with known settings.
 go build -o $WORK/new/bin/go$GOEXE cmd/go &
-go build -o $WORK/bin/check$GOEXE check.go &
+go build -trimpath -o $WORK/bin/check$GOEXE check.go &
 wait
 
 env TESTGOROOT=$GOROOT
 env GOROOT=
 
 # Relocated Executable
-# cp $TESTGOROOT/bin/go$GOEXE $WORK/new/bin/go$GOEXE
 exec $WORK/bin/check$GOEXE $WORK/new/bin/go$GOEXE $TESTGOROOT
 
 # Relocated Tree:

src/cmd/go/testdata/script/goroot_executable_trimpath.txt

@@ -0,0 +1,91 @@
+# Regression test for https://go.dev/issue/62119:
+# A 'go' command cross-compiled with a different GOHOSTOS
+# should be able to locate its GOROOT using os.Executable.
+#
+# (This also tests a 'go' command built with -trimpath
+# that is not cross-compiled, since we need to build that
+# configuration for the test anyway.)
+
+[short] skip 'builds and links another cmd/go'
+
+mkdir $WORK/new/bin
+mkdir $WORK/new/bin/${GOOS}_${GOARCH}
+
+# In this test, we are specifically checking the logic for deriving
+# the value of GOROOT from os.Executable when runtime.GOROOT is
+# trimmed away.
+# GOROOT_FINAL changes the default behavior of runtime.GOROOT,
+# so we explicitly clear it to remove it as a confounding variable.
+env GOROOT_FINAL=
+
+# $GOROOT/bin/go is whatever the user has already installed
+# (using make.bash or similar). We can't make assumptions about what
+# options it may have been built with, such as -trimpath or GOROOT_FINAL.
+# Instead, we build a fresh copy of the binary with known settings.
+go build -trimpath -o $WORK/new/bin/go$GOEXE cmd/go &
+go build -trimpath -o $WORK/bin/check$GOEXE check.go &
+wait
+
+env TESTGOROOT=$GOROOT
+env GOROOT=
+
+# Relocated Executable
+# Since we built with -trimpath and the binary isn't installed in a
+# normal-looking GOROOT, this command should fail.
+
+! exec $WORK/new/bin/go$GOEXE env GOROOT
+stderr '^go: cannot find GOROOT directory: ''go'' binary is trimmed and GOROOT is not set$'
+
+# Cross-compiled binaries in cmd are installed to a ${GOOS}_${GOARCH} subdirectory,
+# so we also want to try a copy there.
+# (Note that the script engine's 'exec' engine already works around
+# https://go.dev/issue/22315, so we don't have to do that explicitly in the
+# 'check' program we use later.)
+cp $WORK/new/bin/go$GOEXE $WORK/new/bin/${GOOS}_${GOARCH}/go$GOEXE
+! exec $WORK/new/bin/${GOOS}_${GOARCH}/go$GOEXE env GOROOT
+stderr '^go: cannot find GOROOT directory: ''go'' binary is trimmed and GOROOT is not set$'
+
+# Relocated Tree:
+# If the binary is sitting in a bin dir next to ../pkg/tool, that counts as a GOROOT,
+# so it should find the new tree.
+mkdir $WORK/new/pkg/tool
+exec $WORK/bin/check$GOEXE $WORK/new/bin/go$GOEXE $WORK/new
+exec $WORK/bin/check$GOEXE $WORK/new/bin/${GOOS}_${GOARCH}/go$GOEXE $WORK/new
+
+-- check.go --
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+func main() {
+	exe := os.Args[1]
+	want := os.Args[2]
+	cmd := exec.Command(exe, "env", "GOROOT")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%s env GOROOT: %v, %s\n", exe, err, out)
+		os.Exit(1)
+	}
+	goroot, err := filepath.EvalSymlinks(strings.TrimSpace(string(out)))
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+	want, err = filepath.EvalSymlinks(want)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+	if !strings.EqualFold(goroot, want) {
+		fmt.Fprintf(os.Stderr, "go env GOROOT:\nhave %s\nwant %s\n", goroot, want)
+		os.Exit(1)
+	}
+	fmt.Fprintf(os.Stderr, "go env GOROOT: %s\n", goroot)
+
+}

src/cmd/go/testdata/script/gotoolchain_local.txt

@@ -34,9 +34,9 @@ env GOTOOLCHAIN=go1.600+auto
 go version
 stdout go1.600
 
-env GOTOOLCHAIN=go1.400+auto
+env GOTOOLCHAIN=go1.400.0+auto
 go version
-stdout go1.400
+stdout go1.400.0
 
 # GOTOOLCHAIN=version+path sets a minimum too.
 env GOTOOLCHAIN=go1.600+path

src/cmd/go/testdata/script/gotoolchain_net.txt

@@ -43,11 +43,13 @@ env GOSUMDB=$oldsumdb
 # Test a real GOTOOLCHAIN
 [short] skip
 [!net:golang.org] skip
+[!net:sum.golang.org] skip
 [!GOOS:darwin] [!GOOS:windows] [!GOOS:linux] skip
 [!GOARCH:amd64] [!GOARCH:arm64] skip
 
 env GOPROXY=
-env GOSUMDB=
+[go-builder] env GOSUMDB=
+[!go-builder] env GOSUMDB=sum.golang.org  # Set explicitly in case GOROOT/go.env is modified.
 env GOTOOLCHAIN=go1.20.1
 
 	# Avoid resolving a "go1.20.1" from the user's real $PATH.

src/cmd/go/testdata/script/gotoolchain_path.txt

@@ -8,11 +8,12 @@ env TESTGO_VERSION=go1.21pre3
 # Compile a fake toolchain to put in the path under various names.
 env GOTOOLCHAIN=
 mkdir $WORK/bin
-[!GOOS:plan9] env PATH=$WORK/bin${:}$PATH
-[GOOS:plan9] env path=$WORK/bin${:}$path
 go build -o $WORK/bin/ ./fakego.go  # adds .exe extension implicitly on Windows
 cp $WORK/bin/fakego$GOEXE $WORK/bin/go1.50.0$GOEXE
 
+[!GOOS:plan9] env PATH=$WORK/bin
+[GOOS:plan9] env path=$WORK/bin
+
 go version
 stdout go1.21pre3
 

src/cmd/go/testdata/script/gotoolchain_version.txt

@@ -1,6 +1,15 @@
-[!net:golang.org] skip
+[!net:proxy.golang.org] skip
 
-env GOPROXY=
+	# In the Go project's official release GOPROXY defaults to proxy.golang.org,
+	# but it may be changed in GOROOT/go.env (such as in third-party
+	# distributions).
+	#
+	# Make sure it is in use here, because the server for releases not served
+	# through the proxy (https://golang.org/toolchain?go-get=1) currently only
+	# serves the latest patch release for each of the supported stable releases.
+
+[go-builder] env GOPROXY=
+[!go-builder] env GOPROXY=https://proxy.golang.org
 
 go list -m -versions go
 stdout 1.20.1 # among others

src/cmd/go/testdata/script/list_issue_59905.txt

@@ -1,8 +1,13 @@
 # Expect no panic
 go list -f '{{if .DepsErrors}}{{.DepsErrors}}{{end}}' -export -e -deps
-cmpenv stdout wanterr
+cmpenv stdout wanterr_59905
 
--- wanterr --
+# Expect no panic (Issue 61816)
+cp level1b_61816.txt level1b/pkg.go
+go list -f '{{if .DepsErrors}}{{.DepsErrors}}{{end}}' -export -e -deps
+cmpenv stdout wanterr_61816
+
+-- wanterr_59905 --
 [# test/main/level1a
 level1a${/}pkg.go:5:2: level2x redeclared in this block
 	level1a${/}pkg.go:4:2: other declaration of level2x
@@ -14,6 +19,23 @@ level1b${/}pkg.go:5:2: level2x redeclared in this block
 level1b${/}pkg.go:5:2: "test/main/level1b/level2y" imported as level2x and not used
 level1b${/}pkg.go:8:39: undefined: level2y
 ]
+-- wanterr_61816 --
+[level1b${/}pkg.go:4:2: package foo is not in std ($GOROOT${/}src${/}foo)]
+[# test/main/level1a
+level1a${/}pkg.go:5:2: level2x redeclared in this block
+	level1a${/}pkg.go:4:2: other declaration of level2x
+level1a${/}pkg.go:5:2: "test/main/level1a/level2y" imported as level2x and not used
+level1a${/}pkg.go:8:39: undefined: level2y
+ level1b${/}pkg.go:4:2: package foo is not in std ($GOROOT${/}src${/}foo)]
+-- level1b_61816.txt --
+package level1b
+
+import (
+	"foo"
+)
+
+func Print() { println(level2x.Value, level2y.Value) }
+
 -- go.mod --
 module test/main
 

src/cmd/go/testdata/script/mod_get_insecure_redirect.txt

@@ -0,0 +1,19 @@
+# golang.org/issue/29591: 'go get' was following plain-HTTP redirects even without -insecure (now replaced by GOINSECURE).
+# golang.org/issue/61877: 'go get' would panic in case of an insecure redirect in module mode
+
+[!git] skip
+
+env GOPRIVATE=vcs-test.golang.org
+
+! go get -d vcs-test.golang.org/insecure/go/insecure
+stderr 'redirected .* to insecure URL'
+
+[short] stop 'builds a git repo'
+
+env GOINSECURE=vcs-test.golang.org/insecure/go/insecure
+go get -d vcs-test.golang.org/insecure/go/insecure
+
+-- go.mod --
+module example
+go 1.21
+

src/cmd/go/testdata/script/mod_get_toolchain.txt

@@ -1,5 +1,5 @@
 # setup
-env TESTGO_VERSION=go1.99.0
+env TESTGO_VERSION=go1.99rc1
 env TESTGO_VERSION_SWITCH=switch
 
 # go get go should use the latest Go 1.23
@@ -7,28 +7,28 @@ cp go.mod.orig go.mod
 go get go
 stderr '^go: upgraded go 1.21 => 1.23.9$'
 grep 'go 1.23.9' go.mod
-grep 'toolchain go1.99.0' go.mod
+grep 'toolchain go1.99rc1' go.mod
 
 # go get go@1.23 should use the latest Go 1.23
 cp go.mod.orig go.mod
 go get go@1.23
 stderr '^go: upgraded go 1.21 => 1.23.9$'
 grep 'go 1.23.9' go.mod
-grep 'toolchain go1.99.0' go.mod
+grep 'toolchain go1.99rc1' go.mod
 
 # go get go@1.22 should use the latest Go 1.22
 cp go.mod.orig go.mod
 go get go@1.22
 stderr '^go: upgraded go 1.21 => 1.22.9$'
 grep 'go 1.22.9' go.mod
-grep 'toolchain go1.99.0' go.mod
+grep 'toolchain go1.99rc1' go.mod
 
 # go get go@patch should use the latest patch release
 go get go@1.22.1
 go get go@patch
 stderr '^go: upgraded go 1.22.1 => 1.22.9$'
 grep 'go 1.22.9' go.mod
-grep 'toolchain go1.99.0' go.mod
+grep 'toolchain go1.99rc1' go.mod
 
 # go get go@1.24 does NOT find the release candidate
 cp go.mod.orig go.mod
@@ -40,20 +40,20 @@ cp go.mod.orig go.mod
 go get go@1.24rc1
 stderr '^go: upgraded go 1.21 => 1.24rc1$'
 grep 'go 1.24rc1' go.mod
-grep 'toolchain go1.99.0' go.mod
+grep 'toolchain go1.99rc1' go.mod
 
 # go get go@latest finds the latest Go 1.23
 cp go.mod.orig go.mod
 go get go@latest
 stderr '^go: upgraded go 1.21 => 1.23.9$'
 grep 'go 1.23.9' go.mod
-grep 'toolchain go1.99.0' go.mod
+grep 'toolchain go1.99rc1' go.mod
 
 # Again, with toolchains.
 
 # go get toolchain should find go1.999testmod.
 go get toolchain
-stderr '^go: upgraded toolchain go1.99.0 => go1.999testmod$'
+stderr '^go: upgraded toolchain go1.99rc1 => go1.999testmod$'
 grep 'go 1.23.9' go.mod
 grep 'toolchain go1.999testmod' go.mod
 
@@ -96,6 +96,33 @@ stderr '^go: added toolchain go1.999testmod$'
 grep 'go 1.21' go.mod
 grep 'toolchain go1.999testmod' go.mod
 
+# Bug fixes.
+
+# go get go@garbage should fail but not crash
+! go get go@garbage
+! stderr panic
+stderr '^go: invalid go version garbage$'
+
+# go get go@go1.21.0 is OK - we silently correct to 1.21.0
+go get go@1.19
+go get go@go1.21.0
+stderr '^go: upgraded go 1.19 => 1.21.0'
+
+# go get toolchain@1.24rc1 is OK too.
+go get toolchain@1.24rc1
+stderr '^go: downgraded toolchain go1.999testmod => go1.24rc1$'
+
+# go get go@1.21 should work if we are the Go 1.21 language version,
+# even though there's no toolchain for it.
+# (Older versions resolve to the latest release in that version, so for example
+# go get go@1.20 might resolve to 1.20.9, but if we're the devel copy of
+# Go 1.21, there's no release yet to resolve to, so we resolve to ourselves.)
+env TESTGO_VERSION=go1.21
+go get go@1.19 toolchain@none
+go get go@1.21
+grep 'go 1.21$' go.mod
+! grep toolchain go.mod
+
 -- go.mod.orig --
 module m
 

src/cmd/go/testdata/script/mod_prefer_compatible.txt

@@ -10,9 +10,9 @@ env GOPROXY=
 env GOSUMDB=
 
 # github.com/russross/blackfriday v2.0.0+incompatible exists,
-# and should be resolved if we ask for v2.0 explicitly.
+# and should be resolved if we ask for it explicitly.
 
-go list -m github.com/russross/blackfriday@v2.0
+go list -m github.com/russross/blackfriday@v2.0.0+incompatible
 stdout '^github.com/russross/blackfriday v2\.0\.0\+incompatible$'
 
 # blackfriday v1.5.2 has a go.mod file, so v1.5.2 should be preferred over
@@ -27,6 +27,7 @@ stdout '^github.com/russross/blackfriday v1\.'
 ! go list -m github.com/russross/blackfriday@patch
 stderr '^go: github.com/russross/blackfriday@patch: can''t query version "patch" of module github.com/russross/blackfriday: no existing version is required$'
 
+
 # If we're fetching directly from version control, ignored +incompatible
 # versions should also be omitted by 'go list'.
 
@@ -38,10 +39,23 @@ stderr '^go: github.com/russross/blackfriday@patch: can''t query version "patch"
 [!git] stop
 env GOPROXY=direct
 
-go list -versions -m github.com/russross/blackfriday github.com/russross/blackfriday
+go list -versions -m github.com/russross/blackfriday
 stdout '^github.com/russross/blackfriday v1\.5\.1 v1\.5\.2' # and possibly others
 ! stdout ' v2\.'
 
+# For this module, v2.1.0 exists and has a go.mod file.
+# 'go list -m github.com/russross/blackfriday@v2.0' will check
+# the latest v2.0 tag, discover that it isn't the right module, and stop there
+# (instead of spending the time to check O(N) previous tags).
+
+! go list -m github.com/russross/blackfriday@v2.0
+stderr '^go: module github.com/russross/blackfriday: no matching versions for query "v2\.0\"'
+
+# (But asking for exactly v2.0.0+incompatible should still succeed.)
+go list -m github.com/russross/blackfriday@v2.0.0+incompatible
+stdout '^github.com/russross/blackfriday v2\.0\.0\+incompatible$'
+
+
 # However, if the latest compatible version does not include a go.mod file,
 # +incompatible versions should still be listed, as they may still reflect the
 # intent of the module author.

src/cmd/go/testdata/script/mod_sumdb_file_path.txt

@@ -1,7 +1,9 @@
 [!net:proxy.golang.org] skip
+[!net:sum.golang.org] skip
 
 env GO111MODULE=on
-env GOSUMDB=
+[go-builder] env GOSUMDB=
+[!go-builder] env GOSUMDB=sum.golang.org  # Set explicitly in case GOROOT/go.env is modified.
 env GOPATH=$WORK/gopath1
 
 # With a file-based proxy with an empty checksum directory,

src/cmd/go/testdata/script/mod_sumdb_golang.txt

@@ -1,13 +1,13 @@
 # Test default GOPROXY and GOSUMDB
-env GOPROXY=
-env GOSUMDB=
-go env GOPROXY
-stdout '^https://proxy.golang.org,direct$'
-go env GOSUMDB
-stdout '^sum.golang.org$'
-env GOPROXY=https://proxy.golang.org
-go env GOSUMDB
-stdout '^sum.golang.org$'
+[go-builder] env GOPROXY=
+[go-builder] env GOSUMDB=
+[go-builder] go env GOPROXY
+[go-builder] stdout '^https://proxy.golang.org,direct$'
+[go-builder] go env GOSUMDB
+[go-builder] stdout '^sum.golang.org$'
+[go-builder] env GOPROXY=https://proxy.golang.org
+[go-builder] go env GOSUMDB
+[go-builder] stdout '^sum.golang.org$'
 
 # Download direct from github.
 
@@ -26,8 +26,8 @@ cp go.sum saved.sum
 # files not listed in go.sum.
 
 go clean -modcache
-env GOSUMDB=
-env GOPROXY=
+env GOSUMDB=sum.golang.org
+env GOPROXY=https://proxy.golang.org,direct
 
 go list -x -m all  # Download go.mod files.
 ! stderr github

src/cmd/go/testdata/script/mod_toolchain_slash.txt

@@ -0,0 +1,32 @@
+[!exec:/bin/sh] skip
+
+chmod 0777 go1.999999-/run.sh
+chmod 0777 run.sh
+
+! go list all
+! stdout 'RAN SCRIPT'
+
+cd subdir
+! go list all
+! stdout 'RAN SCRIPT'
+
+-- go.mod --
+module exploit
+
+go 1.21
+toolchain go1.999999-/run.sh
+-- go1.999999-/run.sh --
+#!/bin/sh
+printf 'RAN SCRIPT\n'
+exit 1
+-- run.sh --
+#!/bin/sh
+printf 'RAN SCRIPT\n'
+exit 1
+-- subdir/go.mod --
+module exploit
+
+go 1.21
+toolchain go1.999999-/../../run.sh
+-- subdir/go1.999999-/README.txt --
+heh heh heh

src/cmd/go/testdata/script/test_compile_multi_pkg.txt

@@ -2,6 +2,10 @@
 
 # Verify test -c can output multiple executables to a directory.
 
+# This test also serves as a regression test for https://go.dev/issue/62221:
+# prior to the fix for that issue, it occasionally failed with ETXTBSY when
+# run on Unix platforms.
+
 go test -c -o $WORK/some/nonexisting/directory/ ./pkg/...
 exists -exec $WORK/some/nonexisting/directory/pkg1.test$GOEXE
 exists -exec $WORK/some/nonexisting/directory/pkg2.test$GOEXE
@@ -43,4 +47,4 @@ package pkg1
 package pkg2
 
 -- anotherpkg/pkg1/pkg1_test.go --
-package pkg1
+package pkg1

src/cmd/internal/obj/riscv/obj.go

@@ -2067,17 +2067,22 @@ func instructionsForProg(p *obj.Prog) []*instruction {
 		return instructionsForStore(p, ins.as, p.To.Reg)
 
 	case ALRW, ALRD:
-		// Set aq to use acquire access ordering, which matches Go's memory requirements.
+		// Set aq to use acquire access ordering
 		ins.funct7 = 2
 		ins.rs1, ins.rs2 = uint32(p.From.Reg), REG_ZERO
 
 	case AADDI, AANDI, AORI, AXORI:
 		inss = instructionsForOpImmediate(p, ins.as, p.Reg)
 
-	case ASCW, ASCD, AAMOSWAPW, AAMOSWAPD, AAMOADDW, AAMOADDD, AAMOANDW, AAMOANDD, AAMOORW, AAMOORD,
+	case ASCW, ASCD:
+		// Set release access ordering
+		ins.funct7 = 1
+		ins.rd, ins.rs1, ins.rs2 = uint32(p.RegTo2), uint32(p.To.Reg), uint32(p.From.Reg)
+
+	case AAMOSWAPW, AAMOSWAPD, AAMOADDW, AAMOADDD, AAMOANDW, AAMOANDD, AAMOORW, AAMOORD,
 		AAMOXORW, AAMOXORD, AAMOMINW, AAMOMIND, AAMOMINUW, AAMOMINUD, AAMOMAXW, AAMOMAXD, AAMOMAXUW, AAMOMAXUD:
-		// Set aq to use acquire access ordering, which matches Go's memory requirements.
-		ins.funct7 = 2
+		// Set aqrl to use acquire & release access ordering
+		ins.funct7 = 3
 		ins.rd, ins.rs1, ins.rs2 = uint32(p.RegTo2), uint32(p.To.Reg), uint32(p.From.Reg)
 
 	case AECALL, AEBREAK, ARDCYCLE, ARDTIME, ARDINSTRET:

src/cmd/link/internal/amd64/asm.go

@@ -446,7 +446,7 @@ func machoreloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sy
 	rs := r.Xsym
 	rt := r.Type
 
-	if ldr.SymType(rs) == sym.SHOSTOBJ || rt == objabi.R_PCREL || rt == objabi.R_GOTPCREL || rt == objabi.R_CALL {
+	if rt == objabi.R_PCREL || rt == objabi.R_GOTPCREL || rt == objabi.R_CALL || ldr.SymType(rs) == sym.SHOSTOBJ || ldr.SymType(s) == sym.SINITARR {
 		if ldr.SymDynid(rs) < 0 {
 			ldr.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", rt, sym.RelocName(arch, rt), ldr.SymName(rs), ldr.SymType(rs), ldr.SymType(rs))
 			return false

src/cmd/link/internal/arm64/asm.go

@@ -545,10 +545,11 @@ func machoreloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sy
 		}
 	}
 
-	if ldr.SymType(rs) == sym.SHOSTOBJ || rt == objabi.R_CALLARM64 ||
+	if rt == objabi.R_CALLARM64 ||
 		rt == objabi.R_ARM64_PCREL_LDST8 || rt == objabi.R_ARM64_PCREL_LDST16 ||
 		rt == objabi.R_ARM64_PCREL_LDST32 || rt == objabi.R_ARM64_PCREL_LDST64 ||
-		rt == objabi.R_ADDRARM64 || rt == objabi.R_ARM64_GOTPCREL {
+		rt == objabi.R_ADDRARM64 || rt == objabi.R_ARM64_GOTPCREL ||
+		ldr.SymType(rs) == sym.SHOSTOBJ || ldr.SymType(s) == sym.SINITARR {
 		if ldr.SymDynid(rs) < 0 {
 			ldr.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", rt, sym.RelocName(arch, rt), ldr.SymName(rs), ldr.SymType(rs), ldr.SymType(rs))
 			return false

src/cmd/link/internal/ld/data.go

@@ -368,7 +368,9 @@ func (st *relocSymState) relocsym(s loader.Sym, P []byte) {
 						o = 0
 					}
 				} else if target.IsDarwin() {
-					if ldr.SymType(rs) != sym.SHOSTOBJ {
+					if ldr.SymType(rs) != sym.SHOSTOBJ && ldr.SymType(s) != sym.SINITARR {
+						// ld-prime drops the offset in data for SINITARR. We need to use
+						// symbol-targeted relocation. See also machoreloc1.
 						o += ldr.SymValue(rs)
 					}
 				} else if target.IsWindows() {

src/cmd/link/internal/ld/deadcode.go

@@ -141,10 +141,26 @@ func (d *deadcodePass) flood() {
 		methods = methods[:0]
 		for i := 0; i < relocs.Count(); i++ {
 			r := relocs.At(i)
-			// When build with "-linkshared", we can't tell if the interface
-			// method in itab will be used or not. Ignore the weak attribute.
-			if r.Weak() && !(d.ctxt.linkShared && d.ldr.IsItab(symIdx)) {
-				continue
+			if r.Weak() {
+				convertWeakToStrong := false
+				// When build with "-linkshared", we can't tell if the
+				// interface method in itab will be used or not.
+				// Ignore the weak attribute.
+				if d.ctxt.linkShared && d.ldr.IsItab(symIdx) {
+					convertWeakToStrong = true
+				}
+				// If the program uses plugins, we can no longer treat
+				// relocs from pkg init functions to outlined map init
+				// fragments as weak, since doing so can cause package
+				// init clashes between the main program and the
+				// plugin. See #62430 for more details.
+				if d.ctxt.canUsePlugins && r.Type().IsDirectCall() {
+					convertWeakToStrong = true
+				}
+				if !convertWeakToStrong {
+					// skip this reloc
+					continue
+				}
 			}
 			t := r.Type()
 			switch t {

src/cmd/link/internal/ld/lib.go

@@ -992,6 +992,11 @@ func typeSymbolMangle(name string) string {
 	if strings.HasPrefix(name, "type:runtime.") {
 		return name
 	}
+	if strings.HasPrefix(name, "go:string.") {
+		// String symbols will be grouped to a single go:string.* symbol.
+		// No need to mangle individual symbol names.
+		return name
+	}
 	if len(name) <= 14 && !strings.Contains(name, "@") { // Issue 19529
 		return name
 	}
@@ -1006,7 +1011,7 @@ func typeSymbolMangle(name string) string {
 	// instantiated symbol, replace type name in []
 	i := strings.IndexByte(name, '[')
 	j := strings.LastIndexByte(name, ']')
-	if j == -1 {
+	if j == -1 || j <= i {
 		j = len(name)
 	}
 	hash := notsha256.Sum256([]byte(name[i+1 : j]))
@@ -1413,6 +1418,10 @@ func (ctxt *Link) hostlink() {
 			// resolving a lazy binding. See issue 38824.
 			// Force eager resolution to work around.
 			argv = append(argv, "-Wl,-flat_namespace", "-Wl,-bind_at_load")
+			if linkerFlagSupported(ctxt.Arch, argv[0], "", "-Wl,-ld_classic") {
+				// Force old linker to work around a bug in Apple's new linker.
+				argv = append(argv, "-Wl,-ld_classic")
+			}
 		}
 		if !combineDwarf {
 			argv = append(argv, "-Wl,-S") // suppress STAB (symbolic debugging) symbols
@@ -1893,6 +1902,16 @@ func (ctxt *Link) hostlink() {
 				out = append(out[:i], out[i+len(noPieWarning):]...)
 			}
 		}
+		if ctxt.IsDarwin() {
+			const bindAtLoadWarning = "ld: warning: -bind_at_load is deprecated on macOS\n"
+			if i := bytes.Index(out, []byte(bindAtLoadWarning)); i >= 0 {
+				// -bind_at_load is deprecated with ld-prime, but needed for
+				// correctness with older versions of ld64. Swallow the warning.
+				// TODO: maybe pass -bind_at_load conditionally based on C
+				// linker version.
+				out = append(out[:i], out[i+len(bindAtLoadWarning):]...)
+			}
+		}
 		ctxt.Logf("%s", out)
 	}
 

src/cmd/link/internal/ld/macho.go

@@ -833,9 +833,9 @@ func asmbMacho(ctxt *Link) {
 		ml.data[2] = uint32(linkoff + s1 + s2 + s3 + s4 + s5) /* stroff */
 		ml.data[3] = uint32(s6)                               /* strsize */
 
-		machodysymtab(ctxt, linkoff+s1+s2)
-
 		if ctxt.LinkMode != LinkExternal {
+			machodysymtab(ctxt, linkoff+s1+s2)
+
 			ml := newMachoLoad(ctxt.Arch, LC_LOAD_DYLINKER, 6)
 			ml.data[0] = 12 /* offset to string */
 			stringtouint32(ml.data[1:], "/usr/lib/dyld")

src/cmd/link/internal/ld/main.go

@@ -197,6 +197,10 @@ func Main(arch *sys.Arch, theArch Arch) {
 
 	checkStrictDups = *FlagStrictDups
 
+	if ctxt.IsDarwin() && ctxt.BuildMode == BuildModeCShared {
+		*FlagW = true // default to -w in c-shared mode on darwin, see #61229
+	}
+
 	if !buildcfg.Experiment.RegabiWrappers {
 		abiInternalVer = 0
 	}

src/cmd/link/internal/loadpe/ldpe.go

@@ -222,7 +222,7 @@ type peLoaderState struct {
 var comdatDefinitions = make(map[string]int64)
 
 // Load loads the PE file pn from input.
-// Symbols from the object file are created via the loader 'l', and
+// Symbols from the object file are created via the loader 'l',
 // and a slice of the text symbols is returned.
 // If an .rsrc section or set of .rsrc$xx sections is found, its symbols are
 // returned as rsrc.

src/cmd/vendor/golang.org/x/arch/x86/x86asm/plan9x.go

@@ -83,6 +83,12 @@ func GoSyntax(inst Inst, pc uint64, symname SymLookup) string {
 		}
 	}
 
+	if inst.Op == CMP {
+		// Use reads-left-to-right ordering for comparisons.
+		// See issue 60920.
+		args[0], args[1] = args[1], args[0]
+	}
+
 	if args != nil {
 		op += " " + strings.Join(args, ", ")
 	}

src/cmd/vendor/golang.org/x/mod/internal/lazyregexp/lazyre.go

@@ -13,7 +13,7 @@ import (
 	"sync"
 )
 
-// Regexp is a wrapper around regexp.Regexp, where the underlying regexp will be
+// Regexp is a wrapper around [regexp.Regexp], where the underlying regexp will be
 // compiled the first time it is needed.
 type Regexp struct {
 	str  string

src/cmd/vendor/golang.org/x/mod/modfile/read.go

@@ -65,7 +65,7 @@ type Comments struct {
 }
 
 // Comment returns the receiver. This isn't useful by itself, but
-// a Comments struct is embedded into all the expression
+// a [Comments] struct is embedded into all the expression
 // implementation types, and this gives each of those a Comment
 // method to satisfy the Expr interface.
 func (c *Comments) Comment() *Comments {

src/cmd/vendor/golang.org/x/mod/modfile/rule.go

@@ -5,17 +5,17 @@
 // Package modfile implements a parser and formatter for go.mod files.
 //
 // The go.mod syntax is described in
-// https://golang.org/cmd/go/#hdr-The_go_mod_file.
+// https://pkg.go.dev/cmd/go/#hdr-The_go_mod_file.
 //
-// The Parse and ParseLax functions both parse a go.mod file and return an
+// The [Parse] and [ParseLax] functions both parse a go.mod file and return an
 // abstract syntax tree. ParseLax ignores unknown statements and may be used to
 // parse go.mod files that may have been developed with newer versions of Go.
 //
-// The File struct returned by Parse and ParseLax represent an abstract
-// go.mod file. File has several methods like AddNewRequire and DropReplace
-// that can be used to programmatically edit a file.
+// The [File] struct returned by Parse and ParseLax represent an abstract
+// go.mod file. File has several methods like [File.AddNewRequire] and
+// [File.DropReplace] that can be used to programmatically edit a file.
 //
-// The Format function formats a File back to a byte slice which can be
+// The [Format] function formats a File back to a byte slice which can be
 // written to a file.
 package modfile
 
@@ -226,7 +226,7 @@ var dontFixRetract VersionFixer = func(_, vers string) (string, error) {
 // data is the content of the file.
 //
 // fix is an optional function that canonicalizes module versions.
-// If fix is nil, all module versions must be canonical (module.CanonicalVersion
+// If fix is nil, all module versions must be canonical ([module.CanonicalVersion]
 // must return the same string).
 func Parse(file string, data []byte, fix VersionFixer) (*File, error) {
 	return parseToFile(file, data, fix, true)
@@ -923,7 +923,7 @@ func (f *File) Format() ([]byte, error) {
 }
 
 // Cleanup cleans up the file f after any edit operations.
-// To avoid quadratic behavior, modifications like DropRequire
+// To avoid quadratic behavior, modifications like [File.DropRequire]
 // clear the entry but do not remove it from the slice.
 // Cleanup cleans out all the cleared entries.
 func (f *File) Cleanup() {
@@ -1075,8 +1075,8 @@ func (f *File) AddNewRequire(path, vers string, indirect bool) {
 // The requirements in req must specify at most one distinct version for each
 // module path.
 //
-// If any existing requirements may be removed, the caller should call Cleanup
-// after all edits are complete.
+// If any existing requirements may be removed, the caller should call
+// [File.Cleanup] after all edits are complete.
 func (f *File) SetRequire(req []*Require) {
 	type elem struct {
 		version  string

src/cmd/vendor/golang.org/x/mod/modfile/work.go

@@ -34,7 +34,7 @@ type Use struct {
 // data is the content of the file.
 //
 // fix is an optional function that canonicalizes module versions.
-// If fix is nil, all module versions must be canonical (module.CanonicalVersion
+// If fix is nil, all module versions must be canonical ([module.CanonicalVersion]
 // must return the same string).
 func ParseWork(file string, data []byte, fix VersionFixer) (*WorkFile, error) {
 	fs, err := parse(file, data)
@@ -83,7 +83,7 @@ func ParseWork(file string, data []byte, fix VersionFixer) (*WorkFile, error) {
 }
 
 // Cleanup cleans up the file f after any edit operations.
-// To avoid quadratic behavior, modifications like DropRequire
+// To avoid quadratic behavior, modifications like [WorkFile.DropRequire]
 // clear the entry but do not remove it from the slice.
 // Cleanup cleans out all the cleared entries.
 func (f *WorkFile) Cleanup() {

src/cmd/vendor/golang.org/x/mod/module/module.go

@@ -4,7 +4,7 @@
 
 // Package module defines the module.Version type along with support code.
 //
-// The module.Version type is a simple Path, Version pair:
+// The [module.Version] type is a simple Path, Version pair:
 //
 //	type Version struct {
 //		Path string
@@ -12,7 +12,7 @@
 //	}
 //
 // There are no restrictions imposed directly by use of this structure,
-// but additional checking functions, most notably Check, verify that
+// but additional checking functions, most notably [Check], verify that
 // a particular path, version pair is valid.
 //
 // # Escaped Paths
@@ -140,7 +140,7 @@ type ModuleError struct {
 	Err     error
 }
 
-// VersionError returns a ModuleError derived from a Version and error,
+// VersionError returns a [ModuleError] derived from a [Version] and error,
 // or err itself if it is already such an error.
 func VersionError(v Version, err error) error {
 	var mErr *ModuleError
@@ -169,7 +169,7 @@ func (e *ModuleError) Unwrap() error { return e.Err }
 // An InvalidVersionError indicates an error specific to a version, with the
 // module path unknown or specified externally.
 //
-// A ModuleError may wrap an InvalidVersionError, but an InvalidVersionError
+// A [ModuleError] may wrap an InvalidVersionError, but an InvalidVersionError
 // must not wrap a ModuleError.
 type InvalidVersionError struct {
 	Version string
@@ -193,8 +193,8 @@ func (e *InvalidVersionError) Error() string {
 func (e *InvalidVersionError) Unwrap() error { return e.Err }
 
 // An InvalidPathError indicates a module, import, or file path doesn't
-// satisfy all naming constraints. See CheckPath, CheckImportPath,
-// and CheckFilePath for specific restrictions.
+// satisfy all naming constraints. See [CheckPath], [CheckImportPath],
+// and [CheckFilePath] for specific restrictions.
 type InvalidPathError struct {
 	Kind string // "module", "import", or "file"
 	Path string
@@ -294,7 +294,7 @@ func fileNameOK(r rune) bool {
 }
 
 // CheckPath checks that a module path is valid.
-// A valid module path is a valid import path, as checked by CheckImportPath,
+// A valid module path is a valid import path, as checked by [CheckImportPath],
 // with three additional constraints.
 // First, the leading path element (up to the first slash, if any),
 // by convention a domain name, must contain only lower-case ASCII letters,
@@ -380,7 +380,7 @@ const (
 // checkPath returns an error describing why the path is not valid.
 // Because these checks apply to module, import, and file paths,
 // and because other checks may be applied, the caller is expected to wrap
-// this error with InvalidPathError.
+// this error with [InvalidPathError].
 func checkPath(path string, kind pathKind) error {
 	if !utf8.ValidString(path) {
 		return fmt.Errorf("invalid UTF-8")
@@ -532,7 +532,7 @@ var badWindowsNames = []string{
 // they require ".vN" instead of "/vN", and for all N, not just N >= 2.
 // SplitPathVersion returns with ok = false when presented with
 // a path whose last path element does not satisfy the constraints
-// applied by CheckPath, such as "example.com/pkg/v1" or "example.com/pkg/v1.2".
+// applied by [CheckPath], such as "example.com/pkg/v1" or "example.com/pkg/v1.2".
 func SplitPathVersion(path string) (prefix, pathMajor string, ok bool) {
 	if strings.HasPrefix(path, "gopkg.in/") {
 		return splitGopkgIn(path)
@@ -582,7 +582,7 @@ func splitGopkgIn(path string) (prefix, pathMajor string, ok bool) {
 // MatchPathMajor reports whether the semantic version v
 // matches the path major version pathMajor.
 //
-// MatchPathMajor returns true if and only if CheckPathMajor returns nil.
+// MatchPathMajor returns true if and only if [CheckPathMajor] returns nil.
 func MatchPathMajor(v, pathMajor string) bool {
 	return CheckPathMajor(v, pathMajor) == nil
 }
@@ -622,7 +622,7 @@ func CheckPathMajor(v, pathMajor string) error {
 // PathMajorPrefix returns the major-version tag prefix implied by pathMajor.
 // An empty PathMajorPrefix allows either v0 or v1.
 //
-// Note that MatchPathMajor may accept some versions that do not actually begin
+// Note that [MatchPathMajor] may accept some versions that do not actually begin
 // with this prefix: namely, it accepts a 'v0.0.0-' prefix for a '.v1'
 // pathMajor, even though that pathMajor implies 'v1' tagging.
 func PathMajorPrefix(pathMajor string) string {
@@ -643,7 +643,7 @@ func PathMajorPrefix(pathMajor string) string {
 }
 
 // CanonicalVersion returns the canonical form of the version string v.
-// It is the same as semver.Canonical(v) except that it preserves the special build suffix "+incompatible".
+// It is the same as [semver.Canonical] except that it preserves the special build suffix "+incompatible".
 func CanonicalVersion(v string) string {
 	cv := semver.Canonical(v)
 	if semver.Build(v) == "+incompatible" {
@@ -652,8 +652,8 @@ func CanonicalVersion(v string) string {
 	return cv
 }
 
-// Sort sorts the list by Path, breaking ties by comparing Version fields.
-// The Version fields are interpreted as semantic versions (using semver.Compare)
+// Sort sorts the list by Path, breaking ties by comparing [Version] fields.
+// The Version fields are interpreted as semantic versions (using [semver.Compare])
 // optionally followed by a tie-breaking suffix introduced by a slash character,
 // like in "v0.0.1/go.mod".
 func Sort(list []Version) {
@@ -793,7 +793,7 @@ func unescapeString(escaped string) (string, bool) {
 }
 
 // MatchPrefixPatterns reports whether any path prefix of target matches one of
-// the glob patterns (as defined by path.Match) in the comma-separated globs
+// the glob patterns (as defined by [path.Match]) in the comma-separated globs
 // list. This implements the algorithm used when matching a module path to the
 // GOPRIVATE environment variable, as described by 'go help module-private'.
 //