[release-branch.go1.21] go1.21.0

Change-Id: Iffac2ce43cd3a48ba420594adc3eab5aa9bcf113
Reviewed-on: https://go-review.googlesource.com/c/go/+/517055
Auto-Submit: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Gopher Robot <gobot@golang.org>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>

VERSION

@@ -0,0 +1,2 @@
+go1.21.0
+time 2023-08-04T20:14:06Z

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
@@ -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>

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/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/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/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/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/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/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/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/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/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/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/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/crypto/tls/handshake_client.go

@@ -936,6 +936,10 @@ func (hs *clientHandshakeState) sendFinished(out []byte) error {
 	return nil
 }
 
+// maxRSAKeySize is the maximum RSA key size in bits that we are willing
+// to verify the signatures of during a TLS handshake.
+const maxRSAKeySize = 8192
+
 // verifyServerCertificate parses and verifies the provided chain, setting
 // c.verifiedChains and c.peerCertificates or sending the appropriate alert.
 func (c *Conn) verifyServerCertificate(certificates [][]byte) error {
@@ -947,6 +951,10 @@ func (c *Conn) verifyServerCertificate(certificates [][]byte) error {
 			c.sendAlert(alertBadCertificate)
 			return errors.New("tls: failed to parse certificate from server: " + err.Error())
 		}
+		if cert.cert.PublicKeyAlgorithm == x509.RSA && cert.cert.PublicKey.(*rsa.PublicKey).N.BitLen() > maxRSAKeySize {
+			c.sendAlert(alertBadCertificate)
+			return fmt.Errorf("tls: server sent certificate containing RSA key larger than %d bits", maxRSAKeySize)
+		}
 		activeHandles[i] = cert
 		certs[i] = cert.cert
 	}

src/crypto/tls/handshake_client_test.go

@@ -2721,3 +2721,81 @@ func testTLS13OnlyClientHelloCipherSuite(t *testing.T, ciphers []uint16) {
 		t.Fatalf("handshake failed: %s", err)
 	}
 }
+
+// discardConn wraps a net.Conn but discards all writes, but reports that they happened.
+type discardConn struct {
+	net.Conn
+}
+
+func (dc *discardConn) Write(data []byte) (int, error) {
+	return len(data), nil
+}
+
+// largeRSAKeyCertPEM contains a 8193 bit RSA key
+const largeRSAKeyCertPEM = `-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----`
+
+func TestHandshakeRSATooBig(t *testing.T) {
+	testCert, _ := pem.Decode([]byte(largeRSAKeyCertPEM))
+
+	c := &Conn{conn: &discardConn{}, config: testConfig.Clone()}
+
+	expectedErr := "tls: server sent certificate containing RSA key larger than 8192 bits"
+	err := c.verifyServerCertificate([][]byte{testCert.Bytes})
+	if err == nil || err.Error() != expectedErr {
+		t.Errorf("Conn.verifyServerCertificate unexpected error: want %q, got %q", expectedErr, err)
+	}
+
+	expectedErr = "tls: client sent certificate containing RSA key larger than 8192 bits"
+	err = c.processCertsFromClient(Certificate{Certificate: [][]byte{testCert.Bytes}})
+	if err == nil || err.Error() != expectedErr {
+		t.Errorf("Conn.processCertsFromClient unexpected error: want %q, got %q", expectedErr, err)
+	}
+}

src/crypto/tls/handshake_server.go

@@ -864,6 +864,10 @@ func (c *Conn) processCertsFromClient(certificate Certificate) error {
 			c.sendAlert(alertBadCertificate)
 			return errors.New("tls: failed to parse client certificate: " + err.Error())
 		}
+		if certs[i].PublicKeyAlgorithm == x509.RSA && certs[i].PublicKey.(*rsa.PublicKey).N.BitLen() > maxRSAKeySize {
+			c.sendAlert(alertBadCertificate)
+			return fmt.Errorf("tls: client sent certificate containing RSA key larger than %d bits", maxRSAKeySize)
+		}
 	}
 
 	if len(certs) == 0 && requiresClientCert(c.config.ClientAuth) {

src/crypto/tls/quic.go

@@ -246,10 +246,15 @@ func (q *QUICConn) HandleData(level QUICEncryptionLevel, data []byte) error {
 	return nil
 }
 
+type QUICSessionTicketOptions struct {
+	// EarlyData specifies whether the ticket may be used for 0-RTT.
+	EarlyData bool
+}
+
 // SendSessionTicket sends a session ticket to the client.
 // It produces connection events, which may be read with NextEvent.
 // Currently, it can only be called once.
-func (q *QUICConn) SendSessionTicket(earlyData bool) error {
+func (q *QUICConn) SendSessionTicket(opts QUICSessionTicketOptions) error {
 	c := q.conn
 	if !c.isHandshakeComplete.Load() {
 		return quicError(errors.New("tls: SendSessionTicket called before handshake completed"))
@@ -261,7 +266,7 @@ func (q *QUICConn) SendSessionTicket(earlyData bool) error {
 		return quicError(errors.New("tls: SendSessionTicket called multiple times"))
 	}
 	q.sessionTicketSent = true
-	return quicError(c.sendSessionTicket(earlyData))
+	return quicError(c.sendSessionTicket(opts.EarlyData))
 }
 
 // ConnectionState returns basic TLS details about the connection.

src/crypto/tls/quic_test.go

@@ -125,7 +125,8 @@ func runTestQUICConnection(ctx context.Context, cli, srv *testQUICConn, onHandle
 		case QUICHandshakeDone:
 			a.complete = true
 			if a == srv {
-				if err := srv.conn.SendSessionTicket(false); err != nil {
+				opts := QUICSessionTicketOptions{}
+				if err := srv.conn.SendSessionTicket(opts); err != nil {
 					return err
 				}
 			}

src/go/types/api.go

@@ -114,11 +114,11 @@ 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 it 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/go/types/builtins.go

@@ -575,6 +575,11 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 		// 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/internal/types/testdata/fixedbugs/issue61486.go

@@ -0,0 +1,9 @@
+// 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 p
+
+func _(s uint) {
+	_ = min(1 << s)
+}

src/log/slog/level.go

@@ -23,7 +23,6 @@ type Level int
 // First, we wanted the default level to be Info, Since Levels are ints, Info is
 // the default value for int, zero.
 //
-
 // Second, we wanted to make it easy to use levels to specify logger verbosity.
 // Since a larger level means a more severe event, a logger that accepts events
 // with smaller (or more negative) level means a more verbose logger. Logger

src/maps/maps.go

@@ -5,34 +5,6 @@
 // Package maps defines various functions useful with maps of any type.
 package maps
 
-import "unsafe"
-
-// keys is implemented in the runtime package.
-//
-//go:noescape
-func keys(m any, slice unsafe.Pointer)
-
-// Keys returns the keys of the map m.
-// The keys will be in an indeterminate order.
-func Keys[M ~map[K]V, K comparable, V any](m M) []K {
-	r := make([]K, 0, len(m))
-	keys(m, unsafe.Pointer(&r))
-	return r
-}
-
-// values is implemented in the runtime package.
-//
-//go:noescape
-func values(m any, slice unsafe.Pointer)
-
-// Values returns the values of the map m.
-// The values will be in an indeterminate order.
-func Values[M ~map[K]V, K comparable, V any](m M) []V {
-	r := make([]V, 0, len(m))
-	values(m, unsafe.Pointer(&r))
-	return r
-}
-
 // Equal reports whether two maps contain the same key/value pairs.
 // Values are compared using ==.
 func Equal[M1, M2 ~map[K]V, K, V comparable](m1 M1, m2 M2) bool {

src/maps/maps_test.go

@@ -6,87 +6,13 @@ package maps
 
 import (
 	"math"
-	"slices"
-	"sort"
 	"strconv"
 	"testing"
-	"unsafe"
 )
 
 var m1 = map[int]int{1: 2, 2: 4, 4: 8, 8: 16}
 var m2 = map[int]string{1: "2", 2: "4", 4: "8", 8: "16"}
 
-func keysForBenchmarking[M ~map[K]V, K comparable, V any](m M, s []K) {
-	keys(m, unsafe.Pointer(&s))
-}
-
-func TestKeys(t *testing.T) {
-	want := []int{1, 2, 4, 8}
-
-	got1 := Keys(m1)
-	sort.Ints(got1)
-	if !slices.Equal(got1, want) {
-		t.Errorf("Keys(%v) = %v, want %v", m1, got1, want)
-	}
-
-	got2 := Keys(m2)
-	sort.Ints(got2)
-	if !slices.Equal(got2, want) {
-		t.Errorf("Keys(%v) = %v, want %v", m2, got2, want)
-	}
-
-	// test for oldbucket code path
-	// We grow from 128 to 256 buckets at size 832 (6.5 * 128).
-	// Then we have to evacuate 128 buckets, which means we'll be done evacuation at 832+128=960 elements inserted.
-	// so 840 is a good number to test for oldbucket code path.
-	var want3 []int
-	var m = make(map[int]int)
-	for i := 0; i < 840; i++ {
-		want3 = append(want3, i)
-		m[i] = i * i
-	}
-
-	got3 := Keys(m)
-	sort.Ints(got3)
-	if !slices.Equal(got3, want3) {
-		t.Errorf("Keys(%v) = %v, want %v", m, got3, want3)
-	}
-}
-
-func valuesForBenchmarking[M ~map[K]V, K comparable, V any](m M, s []V) {
-	values(m, unsafe.Pointer(&s))
-}
-
-func TestValues(t *testing.T) {
-	got1 := Values(m1)
-	want1 := []int{2, 4, 8, 16}
-	sort.Ints(got1)
-	if !slices.Equal(got1, want1) {
-		t.Errorf("Values(%v) = %v, want %v", m1, got1, want1)
-	}
-
-	got2 := Values(m2)
-	want2 := []string{"16", "2", "4", "8"}
-	sort.Strings(got2)
-	if !slices.Equal(got2, want2) {
-		t.Errorf("Values(%v) = %v, want %v", m2, got2, want2)
-	}
-
-	//test for oldbucket code path
-	var want3 []int
-	var m = make(map[int]int)
-	for i := 0; i < 840; i++ {
-		want3 = append(want3, i*i)
-		m[i] = i * i
-	}
-
-	got3 := Values(m)
-	sort.Ints(got3)
-	if !slices.Equal(got3, want3) {
-		t.Errorf("Values(%v) = %v, want %v", m, got3, want3)
-	}
-}
-
 func TestEqual(t *testing.T) {
 	if !Equal(m1, m1) {
 		t.Errorf("Equal(%v, %v) = false, want true", m1, m1)
@@ -256,29 +182,3 @@ func TestCloneWithMapAssign(t *testing.T) {
 		}
 	}
 }
-
-func BenchmarkKeys(b *testing.B) {
-	m := make(map[int]int, 1000000)
-	for i := 0; i < 1000000; i++ {
-		m[i] = i
-	}
-	b.ResetTimer()
-
-	slice := make([]int, 0, len(m))
-	for i := 0; i < b.N; i++ {
-		keysForBenchmarking(m, slice)
-	}
-}
-
-func BenchmarkValues(b *testing.B) {
-	m := make(map[int]int, 1000000)
-	for i := 0; i < 1000000; i++ {
-		m[i] = i
-	}
-	b.ResetTimer()
-
-	slice := make([]int, 0, len(m))
-	for i := 0; i < b.N; i++ {
-		valuesForBenchmarking(m, slice)
-	}
-}

src/net/http/fs.go

@@ -349,13 +349,8 @@ func serveContent(w ResponseWriter, r *Request, name string, modtime time.Time,
 
 	w.WriteHeader(code)
 
-	if r.Method != MethodHead {
-		if sendSize == size {
-			// use Copy in the non-range case to make use of WriterTo if available
-			io.Copy(w, sendContent)
-		} else {
-			io.CopyN(w, sendContent, sendSize)
-		}
+	if r.Method != "HEAD" {
+		io.CopyN(w, sendContent, sendSize)
 	}
 }
 

src/net/http/fs_test.go

@@ -924,7 +924,6 @@ func testServeContent(t *testing.T, mode testMode) {
 		wantContentType  string
 		wantContentRange string
 		wantStatus       int
-		wantContent      []byte
 	}
 	htmlModTime := mustStat(t, "testdata/index.html").ModTime()
 	tests := map[string]testCase{
@@ -1140,24 +1139,6 @@ func testServeContent(t *testing.T, mode testMode) {
 			wantStatus:  412,
 			wantLastMod: htmlModTime.UTC().Format(TimeFormat),
 		},
-		"uses_writeTo_if_available_and_non-range": {
-			content:          &panicOnNonWriterTo{seekWriterTo: strings.NewReader("foobar")},
-			serveContentType: "text/plain; charset=utf-8",
-			wantContentType:  "text/plain; charset=utf-8",
-			wantStatus:       StatusOK,
-			wantContent:      []byte("foobar"),
-		},
-		"do_not_use_writeTo_for_range_requests": {
-			content:          &panicOnWriterTo{ReadSeeker: strings.NewReader("foobar")},
-			serveContentType: "text/plain; charset=utf-8",
-			reqHeader: map[string]string{
-				"Range": "bytes=0-4",
-			},
-			wantContentType:  "text/plain; charset=utf-8",
-			wantContentRange: "bytes 0-4/6",
-			wantStatus:       StatusPartialContent,
-			wantContent:      []byte("fooba"),
-		},
 	}
 	for testName, tt := range tests {
 		var content io.ReadSeeker
@@ -1171,8 +1152,7 @@ func testServeContent(t *testing.T, mode testMode) {
 		} else {
 			content = tt.content
 		}
-		contentOut := &strings.Builder{}
-		for _, method := range []string{MethodGet, MethodHead} {
+		for _, method := range []string{"GET", "HEAD"} {
 			//restore content in case it is consumed by previous method
 			if content, ok := content.(*strings.Reader); ok {
 				content.Seek(0, io.SeekStart)
@@ -1198,8 +1178,7 @@ func testServeContent(t *testing.T, mode testMode) {
 			if err != nil {
 				t.Fatal(err)
 			}
-			contentOut.Reset()
-			io.Copy(contentOut, res.Body)
+			io.Copy(io.Discard, res.Body)
 			res.Body.Close()
 			if res.StatusCode != tt.wantStatus {
 				t.Errorf("test %q using %q: got status = %d; want %d", testName, method, res.StatusCode, tt.wantStatus)
@@ -1213,28 +1192,10 @@ func testServeContent(t *testing.T, mode testMode) {
 			if g, e := res.Header.Get("Last-Modified"), tt.wantLastMod; g != e {
 				t.Errorf("test %q using %q: got last-modified = %q, want %q", testName, method, g, e)
 			}
-			if g, e := contentOut.String(), tt.wantContent; e != nil && method == MethodGet && g != string(e) {
-				t.Errorf("test %q using %q: got unexpected content %q, want %q", testName, method, g, e)
-			}
 		}
 	}
 }
 
-type seekWriterTo interface {
-	io.Seeker
-	io.WriterTo
-}
-
-type panicOnNonWriterTo struct {
-	io.Reader
-	seekWriterTo
-}
-
-type panicOnWriterTo struct {
-	io.ReadSeeker
-	io.WriterTo
-}
-
 // Issue 12991
 func TestServerFileStatError(t *testing.T) {
 	rec := httptest.NewRecorder()

src/net/interface_unix_test.go

@@ -193,6 +193,9 @@ func TestInterfaceArrivalAndDepartureZoneCache(t *testing.T) {
 		t.Skipf("test requires external command: %v", err)
 	}
 	if err := ti.setup(); err != nil {
+		if e := err.Error(); strings.Contains(e, "Permission denied") {
+			t.Skipf("permission denied, skipping test: %v", e)
+		}
 		t.Fatal(err)
 	}
 	defer ti.teardown()

src/runtime/internal/wasitest/tcpecho_test.go

@@ -44,9 +44,9 @@ func TestTCPEcho(t *testing.T) {
 	subProcess.Env = append(os.Environ(), "GOOS=wasip1", "GOARCH=wasm")
 
 	switch os.Getenv("GOWASIRUNTIME") {
-	case "wazero", "":
+	case "wazero":
 		subProcess.Env = append(subProcess.Env, "GOWASIRUNTIMEARGS=--listen="+host)
-	case "wasmtime":
+	case "wasmtime", "":
 		subProcess.Env = append(subProcess.Env, "GOWASIRUNTIMEARGS=--tcplisten="+host)
 	default:
 		t.Skip("WASI runtime does not support sockets")

src/runtime/rt0_windows_amd64.s

@@ -16,12 +16,17 @@ TEXT _rt0_amd64_windows(SB),NOSPLIT|NOFRAME,$-8
 // phase.
 // Leave space for four pointers on the stack as required
 // by the Windows amd64 calling convention.
-TEXT _rt0_amd64_windows_lib(SB),NOSPLIT|NOFRAME,$0x20
+TEXT _rt0_amd64_windows_lib(SB),NOSPLIT|NOFRAME,$40
 	// Create a new thread to do the runtime initialization and return.
+	MOVQ	BX, 32(SP) // callee-saved, preserved across the CALL
+	MOVQ	SP, BX
+	ANDQ	$~15, SP // alignment as per Windows requirement
 	MOVQ	_cgo_sys_thread_create(SB), AX
 	MOVQ	$_rt0_amd64_windows_lib_go(SB), CX
 	MOVQ	$0, DX
 	CALL	AX
+	MOVQ	BX, SP
+	MOVQ	32(SP), BX
 	RET
 
 TEXT _rt0_amd64_windows_lib_go(SB),NOSPLIT|NOFRAME,$0