[release-branch.r58] reflect: disallow Interface method on Value obtained via unexported name

Also remove exp/datafmt that depends on the broken reflect behavior.

««« CL 5267049 / eeca0d4a91a3
reflect: disallow Interface method on Value obtained via unexported name

Had been allowing it for use by fmt, but it is too hard to lock down.
Fix other packages not to depend on it.

R=r, r
CC=golang-dev
https://golang.org/cl/5266054
»»»

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/5297042

doc/devel/release.html

@@ -14,6 +14,86 @@ hg pull
 hg update release.r<i>NN</i>
 </pre>
 
+<h2 id="r58">r58 (released 2011/06/29)</h2>
+
+<p>
+The r58 release corresponds to 
+<code><a href="weekly.html#2011-06-09">weekly.2011-06-09</a></code>
+with additional bug fixes.
+This section highlights the most significant changes in this release.
+For a more detailed summary, see the
+<a href="weekly.html#2011-06-09">weekly release notes</a>.
+For complete information, see the
+<a href="http://code.google.com/p/go/source/list?r=release-branch.r58">Mercurial change list</a>.
+</p>
+
+<h3 id="r58.lang">Language</h3>
+
+<p>
+This release fixes a <a href="http://code.google.com/p/go/source/detail?r=b720749486e1">use of uninitialized memory in programs that misuse <code>goto</code></a>.
+</p>
+
+<h3 id="r58.pkg">Packages</h3>
+
+<p>
+As usual, <a href="/cmd/gofix/">gofix</a> will handle the bulk of the rewrites
+necessary for these changes to package APIs.
+</p>
+
+<p>
+<a href="/pkg/http/">Package http</a> drops the <code>finalURL</code> return
+value from the <a href="/pkg/http/#Client.Get">Client.Get</a> method. The value
+is now available via the new <code>Request</code> field on <a
+href="/pkg/http/#Response">http.Response</a>.
+Most instances of the type map[string][]string in have been
+replaced with the new <a href="/pkg/http/#Values">Values</a> type.
+</p>
+
+<p>
+<a href="/pkg/exec/">Package exec</a> has been redesigned with a more
+convenient and succinct API.
+</p>
+
+<p>
+<a href="/pkg/strconv/">Package strconv</a>'s <a href="/pkg/strconv/#Quote">Quote</a>
+function now escapes only those Unicode code points not classified as printable
+by <a href="/pkg/unicode/#IsPrint">unicode.IsPrint</a>.
+Previously Quote would escape all non-ASCII characters.
+This also affects the <a href="/pkg/fmt/">fmt</a> package's <code>"%q"</code>
+formatting directive. The previous quoting behavior is still available via
+strconv's new <a href="/pkg/strconv/#QuoteToASCII">QuoteToASCII</a> function.   
+</p>
+
+<p>
+<a href="/pkg/os/signal/">Package os/signal</a>'s
+<a href="/pkg/os/#Signal">Signal</a> and 
+<a href="/pkg/os/#UnixSignal">UnixSignal</a> types have been moved to the
+<a href="/pkg/os/">os</a> package.
+</p>
+
+<p>
+<a href="/pkg/image/draw/">Package image/draw</a> is the new name for
+<code>exp/draw</code>. The GUI-related code from <code>exp/draw</code> is now
+located in the <a href="/pkg/exp/gui/">exp/gui</a> package.
+</p>
+
+<h3 id="r58.cmd">Tools</h3>
+
+<p>
+<a href="/cmd/goinstall/">Goinstall</a> now observes the GOPATH environment
+variable to build and install your own code and external libraries outside of
+the Go tree (and avoid writing Makefiles).
+</p>
+
+
+<h3 id="r58.minor">Minor revisions</h3>
+
+<p>r58.1 adds 
+<a href="http://code.google.com/p/go/source/detail?r=293c25943586">build</a> and
+<a href="http://code.google.com/p/go/source/detail?r=bf17e96b6582">runtime</a>
+changes to make Go run on OS X 10.7 Lion.
+</p>
+
 <h2 id="r57">r57 (released 2011/05/03)</h2>
 
 <p>
@@ -162,6 +242,7 @@ For other uses, see the <a href="/pkg/runtime/pprof/">runtime/pprof</a> document
 <h3 id="r57.minor">Minor revisions</h3>
 
 <p>r57.1 fixes a <a href="http://code.google.com/p/go/source/detail?r=ff2bc62726e7145eb2ecc1e0f076998e4a8f86f0">nil pointer dereference in http.FormFile</a>.</p>
+<p>r57.2 fixes a <a href="http://code.google.com/p/go/source/detail?r=063b0ff67d8277df03c956208abc068076818dae">use of uninitialized memory in programs that misuse <code>goto</code></a>.</p>
 
 <h2 id="r56">r56 (released 2011/03/16)</h2>
 

doc/devel/weekly.html

@@ -14,7 +14,7 @@ hg pull
 hg update weekly.<i>YYYY-MM-DD</i>
 </pre>
 
-<h2 id="2011-06-09">2011-06-09</h2>
+<h2 id="2011-06-09">2011-06-09 (<a href="release.html#r58">base for r58</a>)</h2>
 
 <pre>
 This release includes changes to the strconv, http, and exp/draw packages.

doc/docs.html

@@ -23,6 +23,17 @@ concepts: syntax, types, allocation, constants, I/O, sorting, printing,
 goroutines, and channels.
 </p>
 
+<h3 id="course_notes">Course Notes</h3>
+<p>
+Slides from a 3-day course about the Go programming language.
+A more thorough introduction than the tutorial.
+</p>
+<ul>
+<li><a href="GoCourseDay1.pdf">Day 1: Basics</a> <small>[270KB PDF]</small>
+<li><a href="GoCourseDay2.pdf">Day 2: Types, Methods, Interfaces</a> <small>[270KB PDF]</small>
+<li><a href="GoCourseDay3.pdf">Day 3: Concurrency and Communication</a> <small>[180KB PDF]</small>
+</ul>
+
 <h3 id="effective_go"><a href="effective_go.html">Effective Go</a></h3>
 <p>
 A document that gives tips for writing clear, idiomatic Go code.
@@ -209,7 +220,7 @@ from Hoare’s 1978 paper to Go provides insight into how and why Go works as it
 does.
 </i></p>
 
-<h3 id="emerging_go"><a href="talks/gofrontend-gcc-summit-2010.pdf">The Go frontend for GCC</a></h3>
+<h3 id="go_frontend_gcc"><a href="talks/gofrontend-gcc-summit-2010.pdf">The Go frontend for GCC</a></h3>
 <p>
 A description of the Go language frontend for gcc.
 Ian Lance Taylor's paper delivered at the GCC Summit 2010.

doc/go_faq.html

@@ -183,16 +183,6 @@ easier to understand what happens when things combine.
 
 <h2 id="Usage">Usage</h2>
 
-<h3 id="Who_should_use_the_language">
-Who should use the language?</h3>
-
-<p>
-Go is an experiment. We hope adventurous users will give it a try and see
-if they enjoy it. Not every programmer
-will, but we hope enough will find satisfaction in the approach it
-offers to justify further development.
-</p>
-
 <h3 id="Is_Google_using_go_internally"> Is Google using Go internally?</h3>
 
 <p>
@@ -598,6 +588,24 @@ the interface idea. Sometimes, though, they're necessary to resolve ambiguities
 among similar interfaces.
 </p>
 
+<h3 id="convert_slice_of_interface">
+Can I convert a []T to an []interface{}?</h3>
+
+<p>
+Not directly because they do not have the same representation in memory.
+It is necessary to copy the elements individually to the destination
+slice. This example converts a slice of <code>int</code> to a slice of
+<code>interface{}</code>:
+</p>
+
+<pre>
+t := []int{1, 2, 3, 4}
+s := make([]interface{}, len(t))
+for i, v := range t {
+	s[i] = v
+}
+</pre>
+
 <h2 id="values">Values</h2>
 
 <h3 id="conversions">

doc/go_tutorial.html

@@ -10,8 +10,7 @@ After you've read this tutorial, you should look at
 which digs deeper into how the language is used and
 talks about the style and idioms of programming in Go.
 Also, slides from a 3-day course about Go are available.
-Although they're badly out of date, they provide some
-background and a lot of examples:
+They provide some background and a lot of examples:
 <a href='/doc/GoCourseDay1.pdf'>Day 1</a>,
 <a href='/doc/GoCourseDay2.pdf'>Day 2</a>,
 <a href='/doc/GoCourseDay3.pdf'>Day 3</a>.

doc/go_tutorial.txt

@@ -11,8 +11,7 @@ After you've read this tutorial, you should look at
 which digs deeper into how the language is used and
 talks about the style and idioms of programming in Go.
 Also, slides from a 3-day course about Go are available.
-Although they're badly out of date, they provide some
-background and a lot of examples:
+They provide some background and a lot of examples:
 <a href='/doc/GoCourseDay1.pdf'>Day 1</a>,
 <a href='/doc/GoCourseDay2.pdf'>Day 2</a>,
 <a href='/doc/GoCourseDay3.pdf'>Day 3</a>.

src/cmd/5g/gsubr.c

@@ -124,6 +124,64 @@ newplist(void)
 	return pl;
 }
 
+void
+clearstk(void)
+{
+	Plist *pl;
+	Prog *p, *p1, *p2, *p3;
+	Node dst, end, zero, con;
+
+	if(plast->firstpc->to.offset <= 0)
+		return;
+
+	// reestablish context for inserting code
+	// at beginning of function.
+	pl = plast;
+	p1 = pl->firstpc;
+	p2 = p1->link;
+	pc = mal(sizeof(*pc));
+	clearp(pc);
+	p1->link = pc;
+	
+	// zero stack frame
+
+	// MOVW $4(SP), R1
+	nodreg(&dst, types[tptr], 1);
+	p = gins(AMOVW, N, &dst);
+	p->from.type = D_CONST;
+	p->from.reg = REGSP;
+	p->from.offset = 4;
+
+	// MOVW $n(R1), R2
+	nodreg(&end, types[tptr], 2);
+	p = gins(AMOVW, N, &end);
+	p->from.type = D_CONST;
+	p->from.reg = 1;
+	p->from.offset = p1->to.offset;
+	
+	// MOVW $0, R3
+	nodreg(&zero, types[TUINT32], 3);
+	nodconst(&con, types[TUINT32], 0);
+	gmove(&con, &zero);
+
+	// L:
+	//	MOVW.P R3, 0(R1) +4
+	//	CMP R1, R2
+	//	BNE L
+	p = gins(AMOVW, &zero, &dst);
+	p->to.type = D_OREG;
+	p->to.offset = 4;
+	p->scond |= C_PBIT;
+	p3 = p;
+	p = gins(ACMP, &dst, N);
+	raddr(&end, p);
+	patch(gbranch(ABNE, T), p3);
+
+	// continue with original code.
+	gins(ANOP, N, N)->link = p2;
+	pc = P;
+}	
+
 void
 gused(Node *n)
 {

src/cmd/6g/gsubr.c

@@ -120,6 +120,44 @@ newplist(void)
 	return pl;
 }
 
+void
+clearstk(void)
+{
+	Plist *pl;
+	Prog *p1, *p2;
+	Node sp, di, cx, con, ax;
+
+	if((uint32)plast->firstpc->to.offset <= 0)
+		return;
+
+	// reestablish context for inserting code
+	// at beginning of function.
+	pl = plast;
+	p1 = pl->firstpc;
+	p2 = p1->link;
+	pc = mal(sizeof(*pc));
+	clearp(pc);
+	p1->link = pc;
+	
+	// zero stack frame
+	nodreg(&sp, types[tptr], D_SP);
+	nodreg(&di, types[tptr], D_DI);
+	nodreg(&cx, types[TUINT64], D_CX);
+	nodconst(&con, types[TUINT64], (uint32)p1->to.offset / widthptr);
+	gins(ACLD, N, N);
+	gins(AMOVQ, &sp, &di);
+	gins(AMOVQ, &con, &cx);
+	nodconst(&con, types[TUINT64], 0);
+	nodreg(&ax, types[TUINT64], D_AX);
+	gins(AMOVQ, &con, &ax);
+	gins(AREP, N, N);
+	gins(ASTOSQ, N, N);
+
+	// continue with original code.
+	gins(ANOP, N, N)->link = p2;
+	pc = P;
+}	
+
 void
 gused(Node *n)
 {

src/cmd/8g/gsubr.c

@@ -122,6 +122,44 @@ newplist(void)
 	return pl;
 }
 
+void
+clearstk(void)
+{
+	Plist *pl;
+	Prog *p1, *p2;
+	Node sp, di, cx, con, ax;
+
+	if(plast->firstpc->to.offset <= 0)
+		return;
+
+	// reestablish context for inserting code
+	// at beginning of function.
+	pl = plast;
+	p1 = pl->firstpc;
+	p2 = p1->link;
+	pc = mal(sizeof(*pc));
+	clearp(pc);
+	p1->link = pc;
+	
+	// zero stack frame
+	nodreg(&sp, types[tptr], D_SP);
+	nodreg(&di, types[tptr], D_DI);
+	nodreg(&cx, types[TUINT32], D_CX);
+	nodconst(&con, types[TUINT32], p1->to.offset / widthptr);
+	gins(ACLD, N, N);
+	gins(AMOVL, &sp, &di);
+	gins(AMOVL, &con, &cx);
+	nodconst(&con, types[TUINT32], 0);
+	nodreg(&ax, types[TUINT32], D_AX);
+	gins(AMOVL, &con, &ax);
+	gins(AREP, N, N);
+	gins(ASTOSL, N, N);
+
+	// continue with original code.
+	gins(ANOP, N, N)->link = p2;
+	pc = P;
+}	
+
 void
 gused(Node *n)
 {

src/cmd/cgo/gcc.go

@@ -13,6 +13,7 @@ import (
 	"debug/elf"
 	"debug/macho"
 	"debug/pe"
+	"encoding/binary"
 	"flag"
 	"fmt"
 	"go/ast"
@@ -477,7 +478,27 @@ func (p *Package) loadDWARF(f *File, names []*Name) {
 			fmt.Fprintf(&b, "enum { __cgo_enum__%d = %s };\n", i, n.C)
 		}
 	}
-	d := p.gccDebug(b.Bytes())
+
+	// Apple's LLVM-based gcc does not include the enumeration
+	// names and values in its DWARF debug output.  In case we're
+	// using such a gcc, create a data block initialized with the values.
+	// We can read them out of the object file.
+	fmt.Fprintf(&b, "long long __cgodebug_data[] = {\n")
+	for _, n := range names {
+		if n.Kind == "const" {
+			fmt.Fprintf(&b, "\t%s,\n", n.C)
+		} else {
+			fmt.Fprintf(&b, "\t0,\n")
+		}
+	}
+	fmt.Fprintf(&b, "\t0\n")
+	fmt.Fprintf(&b, "};\n")
+
+	d, bo, debugData := p.gccDebug(b.Bytes())
+	enumVal := make([]int64, len(debugData)/8)
+	for i := range enumVal {
+		enumVal[i] = int64(bo.Uint64(debugData[i*8:]))
+	}
 
 	// Scan DWARF info for top-level TagVariable entries with AttrName __cgo__i.
 	types := make([]dwarf.Type, len(names))
@@ -569,9 +590,12 @@ func (p *Package) loadDWARF(f *File, names []*Name) {
 				// Remove injected enum to ensure the value will deep-compare
 				// equally in future loads of the same constant.
 				n.Type.EnumValues[k] = 0, false
+			} else if n.Kind == "const" && i < len(enumVal) {
+				n.Const = strconv.Itoa64(enumVal[i])
 			}
 		}
 	}
+
 }
 
 // rewriteRef rewrites all the C.xxx references in f.AST to refer to the
@@ -593,6 +617,9 @@ func (p *Package) rewriteRef(f *File) {
 	// are trying to do a ,err call.  Also check that
 	// functions are only used in calls.
 	for _, r := range f.Ref {
+		if r.Name.Kind == "const" && r.Name.Const == "" {
+			error(r.Pos(), "unable to find value of constant C.%s", r.Name.Go)
+		}
 		var expr ast.Expr = ast.NewIdent(r.Name.Mangle) // default
 		switch r.Context {
 		case "call", "call2":
@@ -692,29 +719,57 @@ func (p *Package) gccCmd() []string {
 }
 
 // gccDebug runs gcc -gdwarf-2 over the C program stdin and
-// returns the corresponding DWARF data and any messages
-// printed to standard error.
-func (p *Package) gccDebug(stdin []byte) *dwarf.Data {
+// returns the corresponding DWARF data and, if present, debug data block.
+func (p *Package) gccDebug(stdin []byte) (*dwarf.Data, binary.ByteOrder, []byte) {
 	runGcc(stdin, p.gccCmd())
 
-	// Try to parse f as ELF and Mach-O and hope one works.
-	var f interface {
-		DWARF() (*dwarf.Data, os.Error)
-	}
-	var err os.Error
-	if f, err = elf.Open(gccTmp); err != nil {
-		if f, err = macho.Open(gccTmp); err != nil {
-			if f, err = pe.Open(gccTmp); err != nil {
-				fatalf("cannot parse gcc output %s as ELF or Mach-O or PE object", gccTmp)
+	if f, err := macho.Open(gccTmp); err == nil {
+		d, err := f.DWARF()
+		if err != nil {
+			fatalf("cannot load DWARF output from %s: %v", gccTmp, err)
+		}
+		var data []byte
+		if f.Symtab != nil {
+			for i := range f.Symtab.Syms {
+				s := &f.Symtab.Syms[i]
+				// Mach-O still uses a leading _ to denote non-assembly symbols.
+				if s.Name == "_"+"__cgodebug_data" {
+					// Found it.  Now find data section.
+					if i := int(s.Sect) - 1; 0 <= i && i < len(f.Sections) {
+						sect := f.Sections[i]
+						if sect.Addr <= s.Value && s.Value < sect.Addr+sect.Size {
+							if sdat, err := sect.Data(); err == nil {
+								data = sdat[s.Value-sect.Addr:]
+							}
+						}
+					}
+				}
 			}
 		}
+		return d, f.ByteOrder, data
 	}
 
-	d, err := f.DWARF()
-	if err != nil {
-		fatalf("cannot load DWARF debug information from %s: %s", gccTmp, err)
+	// Can skip debug data block in ELF and PE for now.
+	// The DWARF information is complete.
+
+	if f, err := elf.Open(gccTmp); err == nil {
+		d, err := f.DWARF()
+		if err != nil {
+			fatalf("cannot load DWARF output from %s: %v", gccTmp, err)
+		}
+		return d, f.ByteOrder, nil
 	}
-	return d
+
+	if f, err := pe.Open(gccTmp); err == nil {
+		d, err := f.DWARF()
+		if err != nil {
+			fatalf("cannot load DWARF output from %s: %v", gccTmp, err)
+		}
+		return d, binary.LittleEndian, nil
+	}
+
+	fatalf("cannot parse gcc output %s as ELF, Mach-O, PE object", gccTmp)
+	panic("not reached")
 }
 
 // gccDefines runs gcc -E -dM -xc - over the C program stdin

src/cmd/gc/dcl.c

@@ -1241,9 +1241,14 @@ funccompile(Node *n, int isclosure)
 	stksize = 0;
 	dclcontext = PAUTO;
 	funcdepth = n->funcdepth + 1;
+	hasgoto = 0;
 	compile(n);
+	if(hasgoto)
+		clearstk();
 	curfn = nil;
 	funcdepth = 0;
 	dclcontext = PEXTERN;
 }
 
+
+

src/cmd/gc/gen.c

@@ -209,6 +209,7 @@ gen(Node *n)
 		break;
 
 	case OGOTO:
+		hasgoto = 1;
 		newlab(OGOTO, n, N);
 		gjmp(P);
 		break;

src/cmd/gc/go.h

@@ -1255,3 +1255,6 @@ void	zhist(Biobuf *b, int line, vlong offset);
 void	zname(Biobuf *b, Sym *s, int t);
 void	data(void);
 void	text(void);
+
+EXTERN	int	hasgoto;
+void	clearstk(void);

src/cmd/gofix/Makefile

@@ -14,6 +14,7 @@ GOFILES=\
 	httpserver.go\
 	procattr.go\
 	reflect.go\
+	signal.go\
 	typecheck.go\
 
 include ../../Make.cmd

src/cmd/gofix/fix.go

@@ -10,6 +10,7 @@ import (
 	"go/token"
 	"os"
 	"strconv"
+	"strings"
 )
 
 type fix struct {
@@ -258,13 +259,28 @@ func walkBeforeAfter(x interface{}, before, after func(interface{})) {
 
 // imports returns true if f imports path.
 func imports(f *ast.File, path string) bool {
+	return importSpec(f, path) != nil
+}
+
+// importSpec returns the import spec if f imports path,
+// or nil otherwise.
+func importSpec(f *ast.File, path string) *ast.ImportSpec {
 	for _, s := range f.Imports {
-		t, err := strconv.Unquote(s.Path.Value)
-		if err == nil && t == path {
-			return true
+		if importPath(s) == path {
+			return s
 		}
 	}
-	return false
+	return nil
+}
+
+// importPath returns the unquoted import path of s,
+// or "" if the path is not properly quoted.
+func importPath(s *ast.ImportSpec) string {
+	t, err := strconv.Unquote(s.Path.Value)
+	if err == nil {
+		return t
+	}
+	return ""
 }
 
 // isPkgDot returns true if t is the expression "pkg.name"
@@ -420,3 +436,138 @@ func newPkgDot(pos token.Pos, pkg, name string) ast.Expr {
 		},
 	}
 }
+
+// addImport adds the import path to the file f, if absent.
+func addImport(f *ast.File, path string) {
+	if imports(f, path) {
+		return
+	}
+
+	newImport := &ast.ImportSpec{
+		Path: &ast.BasicLit{
+			Kind:  token.STRING,
+			Value: strconv.Quote(path),
+		},
+	}
+
+	var impdecl *ast.GenDecl
+
+	// Find an import decl to add to.
+	for _, decl := range f.Decls {
+		gen, ok := decl.(*ast.GenDecl)
+
+		if ok && gen.Tok == token.IMPORT {
+			impdecl = gen
+			break
+		}
+	}
+
+	// No import decl found.  Add one.
+	if impdecl == nil {
+		impdecl = &ast.GenDecl{
+			Tok: token.IMPORT,
+		}
+		f.Decls = append(f.Decls, nil)
+		copy(f.Decls[1:], f.Decls)
+		f.Decls[0] = impdecl
+	}
+
+	// Ensure the import decl has parentheses, if needed.
+	if len(impdecl.Specs) > 0 && !impdecl.Lparen.IsValid() {
+		impdecl.Lparen = impdecl.Pos()
+	}
+
+	// Assume the import paths are alphabetically ordered.
+	// If they are not, the result is ugly, but legal.
+	insertAt := len(impdecl.Specs) // default to end of specs
+	for i, spec := range impdecl.Specs {
+		impspec := spec.(*ast.ImportSpec)
+		if importPath(impspec) > path {
+			insertAt = i
+			break
+		}
+	}
+
+	impdecl.Specs = append(impdecl.Specs, nil)
+	copy(impdecl.Specs[insertAt+1:], impdecl.Specs[insertAt:])
+	impdecl.Specs[insertAt] = newImport
+
+	f.Imports = append(f.Imports, newImport)
+}
+
+// deleteImport deletes the import path from the file f, if present.
+func deleteImport(f *ast.File, path string) {
+	oldImport := importSpec(f, path)
+
+	// Find the import node that imports path, if any.
+	for i, decl := range f.Decls {
+		gen, ok := decl.(*ast.GenDecl)
+		if !ok || gen.Tok != token.IMPORT {
+			continue
+		}
+		for j, spec := range gen.Specs {
+			impspec := spec.(*ast.ImportSpec)
+
+			if oldImport != impspec {
+				continue
+			}
+
+			// We found an import spec that imports path.
+			// Delete it.
+			copy(gen.Specs[j:], gen.Specs[j+1:])
+			gen.Specs = gen.Specs[:len(gen.Specs)-1]
+
+			// If this was the last import spec in this decl,
+			// delete the decl, too.
+			if len(gen.Specs) == 0 {
+				copy(f.Decls[i:], f.Decls[i+1:])
+				f.Decls = f.Decls[:len(f.Decls)-1]
+			} else if len(gen.Specs) == 1 {
+				gen.Lparen = token.NoPos // drop parens
+			}
+
+			break
+		}
+	}
+
+	// Delete it from f.Imports.
+	for i, imp := range f.Imports {
+		if imp == oldImport {
+			copy(f.Imports[i:], f.Imports[i+1:])
+			f.Imports = f.Imports[:len(f.Imports)-1]
+			break
+		}
+	}
+}
+
+func usesImport(f *ast.File, path string) (used bool) {
+	spec := importSpec(f, path)
+	if spec == nil {
+		return
+	}
+
+	name := spec.Name.String()
+	switch name {
+	case "<nil>":
+		// If the package name is not explicitly specified,
+		// make an educated guess. This is not guaranteed to be correct.
+		lastSlash := strings.LastIndex(path, "/")
+		if lastSlash == -1 {
+			name = path
+		} else {
+			name = path[lastSlash+1:]
+		}
+	case "_", ".":
+		// Not sure if this import is used - err on the side of caution.
+		return true
+	}
+
+	walk(f, func(n interface{}) {
+		sel, ok := n.(*ast.SelectorExpr)
+		if ok && isTopName(sel.X, name) {
+			used = true
+		}
+	})
+
+	return
+}

src/cmd/gofix/signal.go

@@ -0,0 +1,49 @@
+// Copyright 2011 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
+
+import (
+	"go/ast"
+	"strings"
+)
+
+func init() {
+	register(fix{
+		"signal",
+		signal,
+		`Adapt code to types moved from os/signal to signal.
+
+http://codereview.appspot.com/4437091
+`,
+	})
+}
+
+func signal(f *ast.File) (fixed bool) {
+	if !imports(f, "os/signal") {
+		return
+	}
+
+	walk(f, func(n interface{}) {
+		s, ok := n.(*ast.SelectorExpr)
+
+		if !ok || !isTopName(s.X, "signal") {
+			return
+		}
+
+		sel := s.Sel.String()
+		if sel == "Signal" || sel == "UnixSignal" || strings.HasPrefix(sel, "SIG") {
+			s.X = &ast.Ident{Name: "os"}
+			fixed = true
+		}
+	})
+
+	if fixed {
+		addImport(f, "os")
+		if !usesImport(f, "os/signal") {
+			deleteImport(f, "os/signal")
+		}
+	}
+	return
+}

src/cmd/gofix/signal_test.go

@@ -0,0 +1,96 @@
+// Copyright 2011 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
+
+func init() {
+	addTestCases(signalTests)
+}
+
+var signalTests = []testCase{
+	{
+		Name: "signal.0",
+		In: `package main
+
+import (
+	_ "a"
+	"os/signal"
+	_ "z"
+)
+
+type T1 signal.UnixSignal
+type T2 signal.Signal
+
+func f() {
+	_ = signal.SIGHUP
+	_ = signal.Incoming
+}
+`,
+		Out: `package main
+
+import (
+	_ "a"
+	"os"
+	"os/signal"
+	_ "z"
+)
+
+type T1 os.UnixSignal
+type T2 os.Signal
+
+func f() {
+	_ = os.SIGHUP
+	_ = signal.Incoming
+}
+`,
+	},
+	{
+		Name: "signal.1",
+		In: `package main
+
+import (
+	"os"
+	"os/signal"
+)
+
+func f() {
+	var _ os.Error
+	_ = signal.SIGHUP
+}
+`,
+		Out: `package main
+
+import "os"
+
+
+func f() {
+	var _ os.Error
+	_ = os.SIGHUP
+}
+`,
+	},
+	{
+		Name: "signal.2",
+		In: `package main
+
+import "os"
+import "os/signal"
+
+func f() {
+	var _ os.Error
+	_ = signal.SIGHUP
+}
+`,
+		Out: `package main
+
+import "os"
+
+
+func f() {
+	var _ os.Error
+	_ = os.SIGHUP
+}
+`,
+	},
+}

src/cmd/ld/dwarf.c

@@ -1804,7 +1804,7 @@ mkvarname(char* name, int da)
 
 // flush previous compilation unit.
 static void
-flushunit(DWDie *dwinfo, vlong pc, vlong unitstart)
+flushunit(DWDie *dwinfo, vlong pc, vlong unitstart, int32 header_length)
 {
 	vlong here;
 
@@ -1820,7 +1820,9 @@ flushunit(DWDie *dwinfo, vlong pc, vlong unitstart)
 
 		here = cpos();
 		seek(cout, unitstart, 0);
-		LPUT(here - unitstart - sizeof(int32));
+		LPUT(here - unitstart - sizeof(int32));	 // unit_length
+		WPUT(3);  // dwarf version
+		LPUT(header_length); // header lenght starting here
 		cflush();
 		seek(cout, here, 0);
 	}
@@ -1832,7 +1834,7 @@ writelines(void)
 	Prog *q;
 	Sym *s;
 	Auto *a;
-	vlong unitstart, offs;
+	vlong unitstart, headerend, offs;
 	vlong pc, epc, lc, llc, lline;
 	int currfile;
 	int i, lang, da, dt;
@@ -1842,6 +1844,7 @@ writelines(void)
 	char *n, *nn;
 
 	unitstart = -1;
+	headerend = -1;
 	pc = 0;
 	epc = 0;
 	lc = 1;
@@ -1859,7 +1862,7 @@ writelines(void)
 		// we're entering a new compilation unit
 
 		if (inithist(s->autom)) {
-			flushunit(dwinfo, epc, unitstart);
+			flushunit(dwinfo, epc, unitstart, headerend - unitstart - 10);
 			unitstart = cpos();
 
 			if(debug['v'] > 1) {
@@ -1880,10 +1883,10 @@ writelines(void)
 
 			// Write .debug_line Line Number Program Header (sec 6.2.4)
 			// Fields marked with (*) must be changed for 64-bit dwarf
-			LPUT(0);   // unit_length (*), will be filled in later.
+			LPUT(0);   // unit_length (*), will be filled in by flushunit.
 			WPUT(3);   // dwarf version (appendix F)
-			LPUT(11);  // header_length (*), starting here.
-
+			LPUT(0);   // header_length (*), filled in by flushunit.
+			// cpos == unitstart + 4 + 2 + 4
 			cput(1);   // minimum_instruction_length
 			cput(1);   // default_is_stmt
 			cput(LINE_BASE);     // line_base
@@ -1894,17 +1897,15 @@ writelines(void)
 			cput(1);   // standard_opcode_lengths[3]
 			cput(1);   // standard_opcode_lengths[4]
 			cput(0);   // include_directories  (empty)
-			cput(0);   // file_names (empty) (emitted by DW_LNE's below)
-			// header_length ends here.
 
 			for (i=1; i < histfilesize; i++) {
-				cput(0);  // start extended opcode
-				uleb128put(1 + strlen(histfile[i]) + 4);
-				cput(DW_LNE_define_file);
 				strnput(histfile[i], strlen(histfile[i]) + 4);
 				// 4 zeros: the string termination + 3 fields.
 			}
 
+			cput(0);   // terminate file_names.
+			headerend = cpos();
+
 			pc = s->text->pc;
 			epc = pc;
 			currfile = 1;
@@ -2009,7 +2010,7 @@ writelines(void)
 		dwfunc->hash = nil;
 	}
 
-	flushunit(dwinfo, epc, unitstart);
+	flushunit(dwinfo, epc, unitstart, headerend - unitstart - 10);
 	linesize = cpos() - lineo;
 }
 

src/cmd/prof/gopprof

@@ -150,7 +150,8 @@ pprof [options] <profile>
    The /<service> can be $HEAP_PAGE, $PROFILE_PAGE, /pprof/pmuprofile,
                          $GROWTH_PAGE, $CONTENTION_PAGE, /pprof/wall,
                          or /pprof/filteredprofile.
-   For instance: "pprof http://myserver.com:80$HEAP_PAGE".
+   For instance:
+     pprof http://myserver.com:80$HEAP_PAGE
    If /<service> is omitted, the service defaults to $PROFILE_PAGE (cpu profiling).
 pprof --symbols <program>
    Maps addresses to symbol names.  In this mode, stdin should be a
@@ -532,7 +533,7 @@ sub Init() {
     ConfigureObjTools($main::prog)
   }
 
-  # Break the opt_list_prefix into the prefix_list array
+  # Break the opt_lib_prefix into the prefix_list array
   @prefix_list = split (',', $main::opt_lib_prefix);
 
   # Remove trailing / from the prefixes, in the list to prevent
@@ -626,7 +627,7 @@ sub Main() {
     if ($main::opt_disasm) {
       PrintDisassembly($libs, $flat, $cumulative, $main::opt_disasm, $total);
     } elsif ($main::opt_list) {
-      PrintListing($libs, $flat, $cumulative, $main::opt_list);
+      PrintListing($total, $libs, $flat, $cumulative, $main::opt_list, 0);
     } elsif ($main::opt_text) {
       # Make sure the output is empty when have nothing to report
       # (only matters when --heapcheck is given but we must be
@@ -814,7 +815,7 @@ sub InteractiveCommand {
     my $ignore;
     ($routine, $ignore) = ParseInteractiveArgs($3);
 
-    my $profile = ProcessProfile($orig_profile, $symbols, "", $ignore);
+    my $profile = ProcessProfile($total, $orig_profile, $symbols, "", $ignore);
     my $reduced = ReduceProfile($symbols, $profile);
 
     # Get derived profiles
@@ -841,21 +842,22 @@ sub InteractiveCommand {
 
     return 1;
   }
-  if (m/^\s*list\s*(.+)/) {
+  if (m/^\s*(web)?list\s*(.+)/) {
+    my $html = (defined($1) && ($1 eq "web"));
     $main::opt_list = 1;
 
     my $routine;
     my $ignore;
-    ($routine, $ignore) = ParseInteractiveArgs($1);
+    ($routine, $ignore) = ParseInteractiveArgs($2);
 
-    my $profile = ProcessProfile($orig_profile, $symbols, "", $ignore);
+    my $profile = ProcessProfile($total, $orig_profile, $symbols, "", $ignore);
     my $reduced = ReduceProfile($symbols, $profile);
 
     # Get derived profiles
     my $flat = FlatProfile($reduced);
     my $cumulative = CumulativeProfile($reduced);
 
-    PrintListing($libs, $flat, $cumulative, $routine);
+    PrintListing($total, $libs, $flat, $cumulative, $routine, $html);
     return 1;
   }
   if (m/^\s*disasm\s*(.+)/) {
@@ -866,7 +868,7 @@ sub InteractiveCommand {
     ($routine, $ignore) = ParseInteractiveArgs($1);
 
     # Process current profile to account for various settings
-    my $profile = ProcessProfile($orig_profile, $symbols, "", $ignore);
+    my $profile = ProcessProfile($total, $orig_profile, $symbols, "", $ignore);
     my $reduced = ReduceProfile($symbols, $profile);
 
     # Get derived profiles
@@ -890,7 +892,7 @@ sub InteractiveCommand {
     ($focus, $ignore) = ParseInteractiveArgs($2);
 
     # Process current profile to account for various settings
-    my $profile = ProcessProfile($orig_profile, $symbols, $focus, $ignore);
+    my $profile = ProcessProfile($total, $orig_profile, $symbols, $focus, $ignore);
     my $reduced = ReduceProfile($symbols, $profile);
 
     # Get derived profiles
@@ -916,6 +918,7 @@ sub InteractiveCommand {
 
 
 sub ProcessProfile {
+  my $total_count = shift;
   my $orig_profile = shift;
   my $symbols = shift;
   my $focus = shift;
@@ -923,7 +926,6 @@ sub ProcessProfile {
 
   # Process current profile to account for various settings
   my $profile = $orig_profile;
-  my $total_count = TotalProfile($profile);
   printf("Total: %s %s\n", Unparse($total_count), Units());
   if ($focus ne '') {
     $profile = FocusProfile($symbols, $profile, $focus);
@@ -970,6 +972,11 @@ Commands:
   list [routine_regexp] [-ignore1] [-ignore2]
       Show source listing of routines whose names match "routine_regexp"
 
+  weblist [routine_regexp] [-ignore1] [-ignore2]
+      Displays a source listing of routines whose names match "routine_regexp"
+      in a web browser.  You can click on source lines to view the
+      corresponding disassembly.
+
   top [--cum] [-ignore1] [-ignore2]
   top20 [--cum] [-ignore1] [-ignore2]
   top37 [--cum] [-ignore1] [-ignore2]
@@ -1144,7 +1151,7 @@ sub PrintText {
              $sym);
     }
     $lines++;
-    last if ($line_limit >= 0 && $lines > $line_limit);
+    last if ($line_limit >= 0 && $lines >= $line_limit);
   }
 }
 
@@ -1291,11 +1298,32 @@ sub ByName {
 
 # Print source-listing for all all routines that match $main::opt_list
 sub PrintListing {
+  my $total = shift;
   my $libs = shift;
   my $flat = shift;
   my $cumulative = shift;
   my $list_opts = shift;
+  my $html = shift;
+  
+  my $output = \*STDOUT;
+  my $fname = "";
+  
 
+  if ($html) {
+    # Arrange to write the output to a temporary file
+    $fname = TempName($main::next_tmpfile, "html");
+    $main::next_tmpfile++;
+    if (!open(TEMP, ">$fname")) {
+      print STDERR "$fname: $!\n";
+      return;
+    }
+    $output = \*TEMP;
+    print $output HtmlListingHeader();
+    printf $output ("<div class=\"legend\">%s<br>Total: %s %s</div>\n",
+                    $main::prog, Unparse($total), Units());
+  }
+ 
+  my $listed = 0;
   foreach my $lib (@{$libs}) {
     my $symbol_table = GetProcedureBoundaries($lib->[0], $list_opts);
     my $offset = AddressSub($lib->[1], $lib->[3]);
@@ -1307,15 +1335,98 @@ sub PrintListing {
       my $addr = AddressAdd($start_addr, $offset);
       for (my $i = 0; $i < $length; $i++) {
         if (defined($cumulative->{$addr})) {
-          PrintSource($lib->[0], $offset,
-                      $routine, $flat, $cumulative,
-                      $start_addr, $end_addr);
+          $listed += PrintSource(
+            $lib->[0], $offset,
+            $routine, $flat, $cumulative,
+            $start_addr, $end_addr,
+            $html,
+            $output);
           last;
         }
         $addr = AddressInc($addr);
       }
     }
   }
+
+  if ($html) {
+    if ($listed > 0) {
+      print $output HtmlListingFooter();
+      close($output);
+      RunWeb($fname);
+    } else {
+      close($output);
+      unlink($fname);
+    }
+  }
+}
+
+sub HtmlListingHeader {
+  return <<'EOF';
+<DOCTYPE html>
+<html>
+<head>
+<title>Pprof listing</title>
+<style type="text/css">
+body {
+  font-family: sans-serif;
+}
+h1 {
+  font-size: 1.5em;
+  margin-bottom: 4px;
+}
+.legend {
+  font-size: 1.25em;
+}
+.line {
+  color: #aaaaaa;
+}
+.livesrc {
+  color: #0000ff;
+  cursor: pointer;
+}
+.livesrc:hover {
+  background-color: #cccccc;
+}
+.asm {
+  color: #888888;
+  display: none;
+}
+</style>
+<script type="text/javascript">
+function pprof_toggle_asm(e) {
+  var target;
+  if (!e) e = window.event;
+  if (e.target) target = e.target;
+  else if (e.srcElement) target = e.srcElement;
+
+  if (target && target.className == "livesrc") {
+    var asm = target.nextSibling;
+    if (asm && asm.className == "asm") {
+      asm.style.display = (asm.style.display == "block" ? "none" : "block");
+      e.preventDefault();
+      return false;
+    }
+  }
+}
+</script>
+</head>
+<body>
+EOF
+}
+
+sub HtmlListingFooter {
+  return <<'EOF';
+</body>
+</html>
+EOF
+}
+
+sub HtmlEscape {
+  my $text = shift;
+  $text =~ s/&/&amp;/g;
+  $text =~ s/</&lt;/g;
+  $text =~ s/>/&gt;/g;
+  return $text;
 }
 
 # Returns the indentation of the line, if it has any non-whitespace
@@ -1338,6 +1449,8 @@ sub PrintSource {
   my $cumulative = shift;
   my $start_addr = shift;
   my $end_addr = shift;
+  my $html = shift;
+  my $output = shift;
 
   # Disassemble all instructions (just to get line numbers)
   my @instructions = Disassemble($prog, $offset, $start_addr, $end_addr);
@@ -1353,7 +1466,7 @@ sub PrintSource {
   }
   if (!defined($filename)) {
     print STDERR "no filename found in $routine\n";
-    return;
+    return 0;
   }
 
   # Hack 2: assume that the largest line number from $filename is the
@@ -1386,7 +1499,7 @@ sub PrintSource {
   {
     if (!open(FILE, "<$filename")) {
       print STDERR "$filename: $!\n";
-      return;
+      return 0;
     }
     my $l = 0;
     my $first_indentation = -1;
@@ -1414,12 +1527,21 @@ sub PrintSource {
   # Assign all samples to the range $firstline,$lastline,
   # Hack 4: If an instruction does not occur in the range, its samples
   # are moved to the next instruction that occurs in the range.
-  my $samples1 = {};
-  my $samples2 = {};
-  my $running1 = 0;     # Unassigned flat counts
-  my $running2 = 0;     # Unassigned cumulative counts
-  my $total1 = 0;       # Total flat counts
-  my $total2 = 0;       # Total cumulative counts
+  my $samples1 = {};        # Map from line number to flat count
+  my $samples2 = {};        # Map from line number to cumulative count
+  my $running1 = 0;         # Unassigned flat counts
+  my $running2 = 0;         # Unassigned cumulative counts
+  my $total1 = 0;           # Total flat counts
+  my $total2 = 0;           # Total cumulative counts
+  my %disasm = ();          # Map from line number to disassembly
+  my $running_disasm = "";  # Unassigned disassembly
+  my $skip_marker = "---\n";
+  if ($html) {
+    $skip_marker = "";
+    for (my $l = $firstline; $l <= $lastline; $l++) {
+      $disasm{$l} = "";
+    }
+  }
   foreach my $e (@instructions) {
     # Add up counts for all address that fall inside this instruction
     my $c1 = 0;
@@ -1428,6 +1550,15 @@ sub PrintSource {
       $c1 += GetEntry($flat, $a);
       $c2 += GetEntry($cumulative, $a);
     }
+
+    if ($html) {
+      $running_disasm .= sprintf("      %6s %6s \t\t%8s: %s\n",
+                                 HtmlPrintNumber($c1),
+                                 HtmlPrintNumber($c2),
+                                 $e->[0],
+                                 CleanDisassembly($e->[3]));
+    }
+
     $running1 += $c1;
     $running2 += $c2;
     $total1 += $c1;
@@ -1442,6 +1573,10 @@ sub PrintSource {
       AddEntry($samples2, $line, $running2);
       $running1 = 0;
       $running2 = 0;
+      if ($html) {
+        $disasm{$line} .= $running_disasm;
+        $running_disasm = '';
+      }
     }
   }
 
@@ -1449,16 +1584,28 @@ sub PrintSource {
   AddEntry($samples1, $lastline, $running1);
   AddEntry($samples2, $lastline, $running2);
 
-  printf("ROUTINE ====================== %s in %s\n" .
-         "%6s %6s Total %s (flat / cumulative)\n",
-         ShortFunctionName($routine),
-         $filename,
-         Units(),
-         Unparse($total1),
-         Unparse($total2));
+  if ($html) {
+    printf $output (
+      "<h1>%s</h1>%s\n<pre onClick=\"pprof_toggle_asm()\">\n" .
+      "Total:%6s %6s (flat / cumulative %s)\n",
+      HtmlEscape(ShortFunctionName($routine)),
+      HtmlEscape($filename),
+      Unparse($total1),
+      Unparse($total2),
+      Units());
+  } else {
+    printf $output (
+      "ROUTINE ====================== %s in %s\n" .
+      "%6s %6s Total %s (flat / cumulative)\n",
+      ShortFunctionName($routine),
+      $filename,
+      Unparse($total1),
+      Unparse($total2),
+      Units());
+  }
   if (!open(FILE, "<$filename")) {
     print STDERR "$filename: $!\n";
-    return;
+    return 0;
   }
   my $l = 0;
   while (<FILE>) {
@@ -1468,16 +1615,47 @@ sub PrintSource {
         (($l <= $oldlastline + 5) || ($l <= $lastline))) {
       chop;
       my $text = $_;
-      if ($l == $firstline) { printf("---\n"); }
-      printf("%6s %6s %4d: %s\n",
-             UnparseAlt(GetEntry($samples1, $l)),
-             UnparseAlt(GetEntry($samples2, $l)),
-             $l,
-             $text);
-      if ($l == $lastline)  { printf("---\n"); }
+      if ($l == $firstline) { print $output $skip_marker; }
+      my $n1 = GetEntry($samples1, $l);
+      my $n2 = GetEntry($samples2, $l);
+      if ($html) {
+        my $dis = $disasm{$l};
+        if (!defined($dis) || $n1 + $n2 == 0) {
+          # No samples/disassembly for this source line
+          printf $output (
+            "<span class=\"line\">%5d</span> " .
+            "<span class=\"deadsrc\">%6s %6s %s</span>\n",
+            $l,
+            HtmlPrintNumber($n1),
+            HtmlPrintNumber($n2),
+            HtmlEscape($text));
+        } else {
+          printf $output (
+            "<span class=\"line\">%5d</span> " .
+            "<span class=\"livesrc\">%6s %6s %s</span>" .
+            "<span class=\"asm\">%s</span>\n",
+            $l,
+            HtmlPrintNumber($n1),
+            HtmlPrintNumber($n2),
+            HtmlEscape($text),
+            HtmlEscape($dis));
+        }
+      } else {
+        printf $output(
+          "%6s %6s %4d: %s\n",
+          UnparseAlt($n1),
+          UnparseAlt($n2),
+          $l,
+          $text);
+      }
+      if ($l == $lastline)  { print $output $skip_marker; }
     };
   }
   close(FILE);
+  if ($html) {
+    print $output "</pre>\n";
+  }
+  return 1;
 }
 
 # Return the source line for the specified file/linenumber.
@@ -1625,16 +1803,11 @@ sub PrintDisassembledFunction {
       $address =~ s/^0x//;
       $address =~ s/^0*//;
 
-      # Trim symbols
-      my $d = $e->[3];
-      while ($d =~ s/\([^()%]*\)(\s*const)?//g) { } # Argument types, not (%rax)
-      while ($d =~ s/(\w+)<[^<>]*>/$1/g)  { }       # Remove template arguments
-
       printf("%6s %6s    %8s: %6s\n",
              UnparseAlt($flat_count[$x]),
              UnparseAlt($cum_count[$x]),
              $address,
-             $d);
+             CleanDisassembly($e->[3]));
     }
   }
 }
@@ -2254,6 +2427,16 @@ sub UnparseAlt {
   }
 }
 
+# Alternate pretty-printed form: 0 maps to ""
+sub HtmlPrintNumber {
+  my $num = shift;
+  if ($num == 0) {
+    return "";
+  } else {
+    return Unparse($num);
+  }
+}
+
 # Return output units
 sub Units {
   if ($main::profile_type eq 'heap' || $main::profile_type eq 'growth') {
@@ -2415,6 +2598,8 @@ sub RemoveUninterestingFrames {
                       'copyin',
                       'gostring',
                       'gostringsize',
+                      'growslice1',
+                      'appendslice1',
                       'hash_init',
                       'hash_subtable_new',
                       'hash_conv',
@@ -2422,6 +2607,8 @@ sub RemoveUninterestingFrames {
                       'hash_insert_internal',
                       'hash_insert',
                       'mapassign',
+                      'runtime.mapassign',
+                      'runtime.appendslice',
                       'runtime.mapassign1',
                       'makechan',
                       'makemap',
@@ -2433,11 +2620,13 @@ sub RemoveUninterestingFrames {
                       'unsafe.New',
                       'runtime.mallocgc',
                       'runtime.catstring',
+                      'runtime.growslice',
                       'runtime.ifaceT2E',
                       'runtime.ifaceT2I',
                       'runtime.makechan',
                       'runtime.makechan_c',
                       'runtime.makemap',
+                      'runtime.makemap_c',
                       'runtime.makeslice',
                       'runtime.mal',
                       'runtime.slicebytetostring',
@@ -4302,6 +4491,14 @@ sub ShortFunctionName {
   return $function;
 }
 
+# Trim overly long symbols found in disassembler output
+sub CleanDisassembly {
+  my $d = shift;
+  while ($d =~ s/\([^()%]*\)(\s*const)?//g) { } # Argument types, not (%rax)
+  while ($d =~ s/(\w+)<[^<>]*>/$1/g)  { }       # Remove template arguments
+  return $d;
+}
+
 ##### Miscellaneous #####
 
 # Find the right versions of the above object tools to use.  The

src/pkg/Makefile

@@ -76,7 +76,6 @@ DIRS=\
 	encoding/hex\
 	encoding/pem\
 	exec\
-	exp/datafmt\
 	exp/eval\
 	exp/gui\
 	exp/gui/x11\

src/pkg/debug/dwarf/type.go

@@ -352,8 +352,8 @@ func (d *Data) Type(off Offset) (Type, os.Error) {
 			}
 		}
 		if ndim == 0 {
-			err = DecodeError{"info", e.Offset, "missing dimension for array"}
-			goto Error
+			// LLVM generates this for x[].
+			t.Count = -1
 		}
 
 	case TagBaseType:

src/pkg/debug/elf/file.go

@@ -546,6 +546,12 @@ func (f *File) DWARF() (*dwarf.Data, os.Error) {
 	return dwarf.New(abbrev, nil, nil, info, nil, nil, nil, str)
 }
 
+// Symbols returns the symbol table for f.
+func (f *File) Symbols() ([]Symbol, os.Error) {
+	sym, _, err := f.getSymbols(SHT_SYMTAB)
+	return sym, err
+}
+
 type ImportedSymbol struct {
 	Name    string
 	Version string

src/pkg/deps.bash

@@ -15,7 +15,13 @@ fi
 
 # Get list of directories from Makefile
 dirs=$(gomake --no-print-directory echo-dirs)
-dirpat=$(echo $dirs C | sed 's/ /|/g; s/.*/^(&)$/')
+dirpat=$(echo $dirs C | awk '{
+	for(i=1;i<=NF;i++){ 
+		x=$i
+		gsub("/", "\\/", x)
+		printf("/^(%s)$/\n", x)
+	}
+}')
 
 for dir in $dirs; do (
 	cd $dir || exit 1
@@ -30,7 +36,7 @@ for dir in $dirs; do (
 	deps=$(
 		sed -n '/^import.*"/p; /^import[ \t]*(/,/^)/p' $sources /dev/null |
 		cut -d '"' -f2 |
-		egrep "$dirpat" |
+		awk "$dirpat" |
 		grep -v "^$dir\$" |
 		sed 's/$/.install/' |
 		sed 's;^C\.install;runtime/cgo.install;' |

src/pkg/exp/datafmt/Makefile

@@ -1,12 +0,0 @@
-# Copyright 2009 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.
-
-include ../../../Make.inc
-
-TARG=exp/datafmt
-GOFILES=\
-	datafmt.go\
-	parser.go\
-
-include ../../../Make.pkg

src/pkg/exp/datafmt/datafmt.go

@@ -1,731 +0,0 @@
-// Copyright 2009 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 datafmt implements syntax-directed, type-driven formatting
-	of arbitrary data structures. Formatting a data structure consists of
-	two phases: first, a parser reads a format specification and builds a
-	"compiled" format. Then, the format can be applied repeatedly to
-	arbitrary values. Applying a format to a value evaluates to a []byte
-	containing the formatted value bytes, or nil.
-
-	A format specification is a set of package declarations and format rules:
-
-		Format      = [ Entry { ";" Entry } [ ";" ] ] .
-		Entry       = PackageDecl | FormatRule .
-
-	(The syntax of a format specification is presented in the same EBNF
-	notation as used in the Go language specification. The syntax of white
-	space, comments, identifiers, and string literals is the same as in Go.)
-
-	A package declaration binds a package name (such as 'ast') to a
-	package import path (such as '"go/ast"'). Each package used (in
-	a type name, see below) must be declared once before use.
-
-		PackageDecl = PackageName ImportPath .
-		PackageName = identifier .
-		ImportPath  = string .
-
-	A format rule binds a rule name to a format expression. A rule name
-	may be a type name or one of the special names 'default' or '/'.
-	A type name may be the name of a predeclared type (for example, 'int',
-	'float32', etc.), the package-qualified name of a user-defined type
-	(for example, 'ast.MapType'), or an identifier indicating the structure
-	of unnamed composite types ('array', 'chan', 'func', 'interface', 'map',
-	or 'ptr'). Each rule must have a unique name; rules can be declared in
-	any order.
-
-		FormatRule  = RuleName "=" Expression .
-		RuleName    = TypeName | "default" | "/" .
-		TypeName    = [ PackageName "." ] identifier .
-
-	To format a value, the value's type name is used to select the format rule
-	(there is an override mechanism, see below). The format expression of the
-	selected rule specifies how the value is formatted. Each format expression,
-	when applied to a value, evaluates to a byte sequence or nil.
-
-	In its most general form, a format expression is a list of alternatives,
-	each of which is a sequence of operands:
-
-		Expression  = [ Sequence ] { "|" [ Sequence ] } .
-		Sequence    = Operand { Operand } .
-
-	The formatted result produced by an expression is the result of the first
-	alternative sequence that evaluates to a non-nil result; if there is no
-	such alternative, the expression evaluates to nil. The result produced by
-	an operand sequence is the concatenation of the results of its operands.
-	If any operand in the sequence evaluates to nil, the entire sequence
-	evaluates to nil.
-
-	There are five kinds of operands:
-
-		Operand     = Literal | Field | Group | Option | Repetition .
-
-	Literals evaluate to themselves, with two substitutions. First,
-	%-formats expand in the manner of fmt.Printf, with the current value
-	passed as the parameter. Second, the current indentation (see below)
-	is inserted after every newline or form feed character.
-
-		Literal     = string .
-
-	This table shows string literals applied to the value 42 and the
-	corresponding formatted result:
-
-		"foo"       foo
-		"%x"        2a
-		"x = %d"    x = 42
-		"%#x = %d"  0x2a = 42
-
-	A field operand is a field name optionally followed by an alternate
-	rule name. The field name may be an identifier or one of the special
-	names @ or *.
-
-		Field       = FieldName [ ":" RuleName ] .
-		FieldName   = identifier | "@" | "*" .
-
-	If the field name is an identifier, the current value must be a struct,
-	and there must be a field with that name in the struct. The same lookup
-	rules apply as in the Go language (for instance, the name of an anonymous
-	field is the unqualified type name). The field name denotes the field
-	value in the struct. If the field is not found, formatting is aborted
-	and an error message is returned. (TODO consider changing the semantics
-	such that if a field is not found, it evaluates to nil).
-
-	The special name '@' denotes the current value.
-
-	The meaning of the special name '*' depends on the type of the current
-	value:
-
-		array, slice types   array, slice element (inside {} only, see below)
-		interfaces           value stored in interface
-		pointers             value pointed to by pointer
-
-	(Implementation restriction: channel, function and map types are not
-	supported due to missing reflection support).
-
-	Fields are evaluated as follows: If the field value is nil, or an array
-	or slice element does not exist, the result is nil (see below for details
-	on array/slice elements). If the value is not nil the field value is
-	formatted (recursively) using the rule corresponding to its type name,
-	or the alternate rule name, if given.
-
-	The following example shows a complete format specification for a
-	struct 'myPackage.Point'. Assume the package
-
-		package myPackage  // in directory myDir/myPackage
-		type Point struct {
-			name string;
-			x, y int;
-		}
-
-	Applying the format specification
-
-		myPackage "myDir/myPackage";
-		int = "%d";
-		hexInt = "0x%x";
-		string = "---%s---";
-		myPackage.Point = name "{" x ", " y:hexInt "}";
-
-	to the value myPackage.Point{"foo", 3, 15} results in
-
-		---foo---{3, 0xf}
-
-	Finally, an operand may be a grouped, optional, or repeated expression.
-	A grouped expression ("group") groups a more complex expression (body)
-	so that it can be used in place of a single operand:
-
-		Group       = "(" [ Indentation ">>" ] Body ")" .
-		Indentation = Expression .
-		Body        = Expression .
-
-	A group body may be prefixed by an indentation expression followed by '>>'.
-	The indentation expression is applied to the current value like any other
-	expression and the result, if not nil, is appended to the current indentation
-	during the evaluation of the body (see also formatting state, below).
-
-	An optional expression ("option") is enclosed in '[]' brackets.
-
-		Option      = "[" Body "]" .
-
-	An option evaluates to its body, except that if the body evaluates to nil,
-	the option expression evaluates to an empty []byte. Thus an option's purpose
-	is to protect the expression containing the option from a nil operand.
-
-	A repeated expression ("repetition") is enclosed in '{}' braces.
-
-		Repetition  = "{" Body [ "/" Separator ] "}" .
-		Separator   = Expression .
-
-	A repeated expression is evaluated as follows: The body is evaluated
-	repeatedly and its results are concatenated until the body evaluates
-	to nil. The result of the repetition is the (possibly empty) concatenation,
-	but it is never nil. An implicit index is supplied for the evaluation of
-	the body: that index is used to address elements of arrays or slices. If
-	the corresponding elements do not exist, the field denoting the element
-	evaluates to nil (which in turn may terminate the repetition).
-
-	The body of a repetition may be followed by a '/' and a "separator"
-	expression. If the separator is present, it is invoked between repetitions
-	of the body.
-
-	The following example shows a complete format specification for formatting
-	a slice of unnamed type. Applying the specification
-
-		int = "%b";
-		array = { * / ", " };  // array is the type name for an unnamed slice
-
-	to the value '[]int{2, 3, 5, 7}' results in
-
-		10, 11, 101, 111
-
-	Default rule: If a format rule named 'default' is present, it is used for
-	formatting a value if no other rule was found. A common default rule is
-
-		default = "%v"
-
-	to provide default formatting for basic types without having to specify
-	a specific rule for each basic type.
-
-	Global separator rule: If a format rule named '/' is present, it is
-	invoked with the current value between literals. If the separator
-	expression evaluates to nil, it is ignored.
-
-	For instance, a global separator rule may be used to punctuate a sequence
-	of values with commas. The rules:
-
-		default = "%v";
-		/ = ", ";
-
-	will format an argument list by printing each one in its default format,
-	separated by a comma and a space.
-*/
-package datafmt
-
-import (
-	"bytes"
-	"fmt"
-	"go/token"
-	"io"
-	"os"
-	"reflect"
-	"runtime"
-)
-
-
-// ----------------------------------------------------------------------------
-// Format representation
-
-// Custom formatters implement the Formatter function type.
-// A formatter is invoked with the current formatting state, the
-// value to format, and the rule name under which the formatter
-// was installed (the same formatter function may be installed
-// under different names). The formatter may access the current state
-// to guide formatting and use State.Write to append to the state's
-// output.
-//
-// A formatter must return a boolean value indicating if it evaluated
-// to a non-nil value (true), or a nil value (false).
-//
-type Formatter func(state *State, value interface{}, ruleName string) bool
-
-
-// A FormatterMap is a set of custom formatters.
-// It maps a rule name to a formatter function.
-//
-type FormatterMap map[string]Formatter
-
-
-// A parsed format expression is built from the following nodes.
-//
-type (
-	expr interface{}
-
-	alternatives []expr // x | y | z
-
-	sequence []expr // x y z
-
-	literal [][]byte // a list of string segments, possibly starting with '%'
-
-	field struct {
-		fieldName string // including "@", "*"
-		ruleName  string // "" if no rule name specified
-	}
-
-	group struct {
-		indent, body expr // (indent >> body)
-	}
-
-	option struct {
-		body expr // [body]
-	}
-
-	repetition struct {
-		body, separator expr // {body / separator}
-	}
-
-	custom struct {
-		ruleName string
-		fun      Formatter
-	}
-)
-
-
-// A Format is the result of parsing a format specification.
-// The format may be applied repeatedly to format values.
-//
-type Format map[string]expr
-
-
-// ----------------------------------------------------------------------------
-// Formatting
-
-// An application-specific environment may be provided to Format.Apply;
-// the environment is available inside custom formatters via State.Env().
-// Environments must implement copying; the Copy method must return an
-// complete copy of the receiver. This is necessary so that the formatter
-// can save and restore an environment (in case of an absent expression).
-//
-// If the Environment doesn't change during formatting (this is under
-// control of the custom formatters), the Copy function can simply return
-// the receiver, and thus can be very light-weight.
-//
-type Environment interface {
-	Copy() Environment
-}
-
-
-// State represents the current formatting state.
-// It is provided as argument to custom formatters.
-//
-type State struct {
-	fmt       Format         // format in use
-	env       Environment    // user-supplied environment
-	errors    chan os.Error  // not chan *Error (errors <- nil would be wrong!)
-	hasOutput bool           // true after the first literal has been written
-	indent    bytes.Buffer   // current indentation
-	output    bytes.Buffer   // format output
-	linePos   token.Position // position of line beginning (Column == 0)
-	default_  expr           // possibly nil
-	separator expr           // possibly nil
-}
-
-
-func newState(fmt Format, env Environment, errors chan os.Error) *State {
-	s := new(State)
-	s.fmt = fmt
-	s.env = env
-	s.errors = errors
-	s.linePos = token.Position{Line: 1}
-
-	// if we have a default rule, cache it's expression for fast access
-	if x, found := fmt["default"]; found {
-		s.default_ = x
-	}
-
-	// if we have a global separator rule, cache it's expression for fast access
-	if x, found := fmt["/"]; found {
-		s.separator = x
-	}
-
-	return s
-}
-
-
-// Env returns the environment passed to Format.Apply.
-func (s *State) Env() interface{} { return s.env }
-
-
-// LinePos returns the position of the current line beginning
-// in the state's output buffer. Line numbers start at 1.
-//
-func (s *State) LinePos() token.Position { return s.linePos }
-
-
-// Pos returns the position of the next byte to be written to the
-// output buffer. Line numbers start at 1.
-//
-func (s *State) Pos() token.Position {
-	offs := s.output.Len()
-	return token.Position{Line: s.linePos.Line, Column: offs - s.linePos.Offset, Offset: offs}
-}
-
-
-// Write writes data to the output buffer, inserting the indentation
-// string after each newline or form feed character. It cannot return an error.
-//
-func (s *State) Write(data []byte) (int, os.Error) {
-	n := 0
-	i0 := 0
-	for i, ch := range data {
-		if ch == '\n' || ch == '\f' {
-			// write text segment and indentation
-			n1, _ := s.output.Write(data[i0 : i+1])
-			n2, _ := s.output.Write(s.indent.Bytes())
-			n += n1 + n2
-			i0 = i + 1
-			s.linePos.Offset = s.output.Len()
-			s.linePos.Line++
-		}
-	}
-	n3, _ := s.output.Write(data[i0:])
-	return n + n3, nil
-}
-
-
-type checkpoint struct {
-	env       Environment
-	hasOutput bool
-	outputLen int
-	linePos   token.Position
-}
-
-
-func (s *State) save() checkpoint {
-	saved := checkpoint{nil, s.hasOutput, s.output.Len(), s.linePos}
-	if s.env != nil {
-		saved.env = s.env.Copy()
-	}
-	return saved
-}
-
-
-func (s *State) restore(m checkpoint) {
-	s.env = m.env
-	s.output.Truncate(m.outputLen)
-}
-
-
-func (s *State) error(msg string) {
-	s.errors <- os.NewError(msg)
-	runtime.Goexit()
-}
-
-
-// TODO At the moment, unnamed types are simply mapped to the default
-//      names below. For instance, all unnamed arrays are mapped to
-//      'array' which is not really sufficient. Eventually one may want
-//      to be able to specify rules for say an unnamed slice of T.
-//
-
-func typename(typ reflect.Type) string {
-	switch typ.Kind() {
-	case reflect.Array:
-		return "array"
-	case reflect.Slice:
-		return "array"
-	case reflect.Chan:
-		return "chan"
-	case reflect.Func:
-		return "func"
-	case reflect.Interface:
-		return "interface"
-	case reflect.Map:
-		return "map"
-	case reflect.Ptr:
-		return "ptr"
-	}
-	return typ.String()
-}
-
-func (s *State) getFormat(name string) expr {
-	if fexpr, found := s.fmt[name]; found {
-		return fexpr
-	}
-
-	if s.default_ != nil {
-		return s.default_
-	}
-
-	s.error(fmt.Sprintf("no format rule for type: '%s'", name))
-	return nil
-}
-
-
-// eval applies a format expression fexpr to a value. If the expression
-// evaluates internally to a non-nil []byte, that slice is appended to
-// the state's output buffer and eval returns true. Otherwise, eval
-// returns false and the state remains unchanged.
-//
-func (s *State) eval(fexpr expr, value reflect.Value, index int) bool {
-	// an empty format expression always evaluates
-	// to a non-nil (but empty) []byte
-	if fexpr == nil {
-		return true
-	}
-
-	switch t := fexpr.(type) {
-	case alternatives:
-		// append the result of the first alternative that evaluates to
-		// a non-nil []byte to the state's output
-		mark := s.save()
-		for _, x := range t {
-			if s.eval(x, value, index) {
-				return true
-			}
-			s.restore(mark)
-		}
-		return false
-
-	case sequence:
-		// append the result of all operands to the state's output
-		// unless a nil result is encountered
-		mark := s.save()
-		for _, x := range t {
-			if !s.eval(x, value, index) {
-				s.restore(mark)
-				return false
-			}
-		}
-		return true
-
-	case literal:
-		// write separator, if any
-		if s.hasOutput {
-			// not the first literal
-			if s.separator != nil {
-				sep := s.separator // save current separator
-				s.separator = nil  // and disable it (avoid recursion)
-				mark := s.save()
-				if !s.eval(sep, value, index) {
-					s.restore(mark)
-				}
-				s.separator = sep // enable it again
-			}
-		}
-		s.hasOutput = true
-		// write literal segments
-		for _, lit := range t {
-			if len(lit) > 1 && lit[0] == '%' {
-				// segment contains a %-format at the beginning
-				if lit[1] == '%' {
-					// "%%" is printed as a single "%"
-					s.Write(lit[1:])
-				} else {
-					// use s instead of s.output to get indentation right
-					fmt.Fprintf(s, string(lit), value.Interface())
-				}
-			} else {
-				// segment contains no %-formats
-				s.Write(lit)
-			}
-		}
-		return true // a literal never evaluates to nil
-
-	case *field:
-		// determine field value
-		switch t.fieldName {
-		case "@":
-			// field value is current value
-
-		case "*":
-			// indirection: operation is type-specific
-			switch v := value; v.Kind() {
-			case reflect.Array:
-				if v.Len() <= index {
-					return false
-				}
-				value = v.Index(index)
-
-			case reflect.Slice:
-				if v.IsNil() || v.Len() <= index {
-					return false
-				}
-				value = v.Index(index)
-
-			case reflect.Map:
-				s.error("reflection support for maps incomplete")
-
-			case reflect.Ptr:
-				if v.IsNil() {
-					return false
-				}
-				value = v.Elem()
-
-			case reflect.Interface:
-				if v.IsNil() {
-					return false
-				}
-				value = v.Elem()
-
-			case reflect.Chan:
-				s.error("reflection support for chans incomplete")
-
-			case reflect.Func:
-				s.error("reflection support for funcs incomplete")
-
-			default:
-				s.error(fmt.Sprintf("error: * does not apply to `%s`", value.Type()))
-			}
-
-		default:
-			// value is value of named field
-			var field reflect.Value
-			if sval := value; sval.Kind() == reflect.Struct {
-				field = sval.FieldByName(t.fieldName)
-				if !field.IsValid() {
-					// TODO consider just returning false in this case
-					s.error(fmt.Sprintf("error: no field `%s` in `%s`", t.fieldName, value.Type()))
-				}
-			}
-			value = field
-		}
-
-		// determine rule
-		ruleName := t.ruleName
-		if ruleName == "" {
-			// no alternate rule name, value type determines rule
-			ruleName = typename(value.Type())
-		}
-		fexpr = s.getFormat(ruleName)
-
-		mark := s.save()
-		if !s.eval(fexpr, value, index) {
-			s.restore(mark)
-			return false
-		}
-		return true
-
-	case *group:
-		// remember current indentation
-		indentLen := s.indent.Len()
-
-		// update current indentation
-		mark := s.save()
-		s.eval(t.indent, value, index)
-		// if the indentation evaluates to nil, the state's output buffer
-		// didn't change - either way it's ok to append the difference to
-		// the current indentation
-		s.indent.Write(s.output.Bytes()[mark.outputLen:s.output.Len()])
-		s.restore(mark)
-
-		// format group body
-		mark = s.save()
-		b := true
-		if !s.eval(t.body, value, index) {
-			s.restore(mark)
-			b = false
-		}
-
-		// reset indentation
-		s.indent.Truncate(indentLen)
-		return b
-
-	case *option:
-		// evaluate the body and append the result to the state's output
-		// buffer unless the result is nil
-		mark := s.save()
-		if !s.eval(t.body, value, 0) { // TODO is 0 index correct?
-			s.restore(mark)
-		}
-		return true // an option never evaluates to nil
-
-	case *repetition:
-		// evaluate the body and append the result to the state's output
-		// buffer until a result is nil
-		for i := 0; ; i++ {
-			mark := s.save()
-			// write separator, if any
-			if i > 0 && t.separator != nil {
-				// nil result from separator is ignored
-				mark := s.save()
-				if !s.eval(t.separator, value, i) {
-					s.restore(mark)
-				}
-			}
-			if !s.eval(t.body, value, i) {
-				s.restore(mark)
-				break
-			}
-		}
-		return true // a repetition never evaluates to nil
-
-	case *custom:
-		// invoke the custom formatter to obtain the result
-		mark := s.save()
-		if !t.fun(s, value.Interface(), t.ruleName) {
-			s.restore(mark)
-			return false
-		}
-		return true
-	}
-
-	panic("unreachable")
-	return false
-}
-
-
-// Eval formats each argument according to the format
-// f and returns the resulting []byte and os.Error. If
-// an error occurred, the []byte contains the partially
-// formatted result. An environment env may be passed
-// in which is available in custom formatters through
-// the state parameter.
-//
-func (f Format) Eval(env Environment, args ...interface{}) ([]byte, os.Error) {
-	if f == nil {
-		return nil, os.NewError("format is nil")
-	}
-
-	errors := make(chan os.Error)
-	s := newState(f, env, errors)
-
-	go func() {
-		for _, v := range args {
-			fld := reflect.ValueOf(v)
-			if !fld.IsValid() {
-				errors <- os.NewError("nil argument")
-				return
-			}
-			mark := s.save()
-			if !s.eval(s.getFormat(typename(fld.Type())), fld, 0) { // TODO is 0 index correct?
-				s.restore(mark)
-			}
-		}
-		errors <- nil // no errors
-	}()
-
-	err := <-errors
-	return s.output.Bytes(), err
-}
-
-
-// ----------------------------------------------------------------------------
-// Convenience functions
-
-// Fprint formats each argument according to the format f
-// and writes to w. The result is the total number of bytes
-// written and an os.Error, if any.
-//
-func (f Format) Fprint(w io.Writer, env Environment, args ...interface{}) (int, os.Error) {
-	data, err := f.Eval(env, args...)
-	if err != nil {
-		// TODO should we print partial result in case of error?
-		return 0, err
-	}
-	return w.Write(data)
-}
-
-
-// Print formats each argument according to the format f
-// and writes to standard output. The result is the total
-// number of bytes written and an os.Error, if any.
-//
-func (f Format) Print(args ...interface{}) (int, os.Error) {
-	return f.Fprint(os.Stdout, nil, args...)
-}
-
-
-// Sprint formats each argument according to the format f
-// and returns the resulting string. If an error occurs
-// during formatting, the result string contains the
-// partially formatted result followed by an error message.
-//
-func (f Format) Sprint(args ...interface{}) string {
-	var buf bytes.Buffer
-	_, err := f.Fprint(&buf, nil, args...)
-	if err != nil {
-		var i interface{} = args
-		fmt.Fprintf(&buf, "--- Sprint(%s) failed: %v", fmt.Sprint(i), err)
-	}
-	return buf.String()
-}

src/pkg/exp/datafmt/datafmt_test.go

@@ -1,351 +0,0 @@
-// Copyright 2009 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 datafmt
-
-import (
-	"fmt"
-	"testing"
-	"go/token"
-)
-
-
-var fset = token.NewFileSet()
-
-
-func parse(t *testing.T, form string, fmap FormatterMap) Format {
-	f, err := Parse(fset, "", []byte(form), fmap)
-	if err != nil {
-		t.Errorf("Parse(%s): %v", form, err)
-		return nil
-	}
-	return f
-}
-
-
-func verify(t *testing.T, f Format, expected string, args ...interface{}) {
-	if f == nil {
-		return // allow other tests to run
-	}
-	result := f.Sprint(args...)
-	if result != expected {
-		t.Errorf(
-			"result  : `%s`\nexpected: `%s`\n\n",
-			result, expected)
-	}
-}
-
-
-func formatter(s *State, value interface{}, rule_name string) bool {
-	switch rule_name {
-	case "/":
-		fmt.Fprintf(s, "%d %d %d", s.Pos().Line, s.LinePos().Column, s.Pos().Column)
-		return true
-	case "blank":
-		s.Write([]byte{' '})
-		return true
-	case "int":
-		if value.(int)&1 == 0 {
-			fmt.Fprint(s, "even ")
-		} else {
-			fmt.Fprint(s, "odd ")
-		}
-		return true
-	case "nil":
-		return false
-	case "testing.T":
-		s.Write([]byte("testing.T"))
-		return true
-	}
-	panic("unreachable")
-	return false
-}
-
-
-func TestCustomFormatters(t *testing.T) {
-	fmap0 := FormatterMap{"/": formatter}
-	fmap1 := FormatterMap{"int": formatter, "blank": formatter, "nil": formatter}
-	fmap2 := FormatterMap{"testing.T": formatter}
-
-	f := parse(t, `int=`, fmap0)
-	verify(t, f, ``, 1, 2, 3)
-
-	f = parse(t, `int="#"`, nil)
-	verify(t, f, `###`, 1, 2, 3)
-
-	f = parse(t, `int="#";string="%s"`, fmap0)
-	verify(t, f, "#1 0 1#1 0 7#1 0 13\n2 0 0foo2 0 8\n", 1, 2, 3, "\n", "foo", "\n")
-
-	f = parse(t, ``, fmap1)
-	verify(t, f, `even odd even odd `, 0, 1, 2, 3)
-
-	f = parse(t, `/ =@:blank; float64="#"`, fmap1)
-	verify(t, f, `# # #`, 0.0, 1.0, 2.0)
-
-	f = parse(t, `float64=@:nil`, fmap1)
-	verify(t, f, ``, 0.0, 1.0, 2.0)
-
-	f = parse(t, `testing "testing"; ptr=*`, fmap2)
-	verify(t, f, `testing.T`, t)
-
-	// TODO needs more tests
-}
-
-
-// ----------------------------------------------------------------------------
-// Formatting of basic and simple composite types
-
-func check(t *testing.T, form, expected string, args ...interface{}) {
-	f := parse(t, form, nil)
-	if f == nil {
-		return // allow other tests to run
-	}
-	result := f.Sprint(args...)
-	if result != expected {
-		t.Errorf(
-			"format  : %s\nresult  : `%s`\nexpected: `%s`\n\n",
-			form, result, expected)
-	}
-}
-
-
-func TestBasicTypes(t *testing.T) {
-	check(t, ``, ``)
-	check(t, `bool=":%v"`, `:true:false`, true, false)
-	check(t, `int="%b %d %o 0x%x"`, `101010 42 52 0x2a`, 42)
-
-	check(t, `int="%"`, `%`, 42)
-	check(t, `int="%%"`, `%`, 42)
-	check(t, `int="**%%**"`, `**%**`, 42)
-	check(t, `int="%%%%%%"`, `%%%`, 42)
-	check(t, `int="%%%d%%"`, `%42%`, 42)
-
-	const i = -42
-	const is = `-42`
-	check(t, `int  ="%d"`, is, i)
-	check(t, `int8 ="%d"`, is, int8(i))
-	check(t, `int16="%d"`, is, int16(i))
-	check(t, `int32="%d"`, is, int32(i))
-	check(t, `int64="%d"`, is, int64(i))
-
-	const u = 42
-	const us = `42`
-	check(t, `uint  ="%d"`, us, uint(u))
-	check(t, `uint8 ="%d"`, us, uint8(u))
-	check(t, `uint16="%d"`, us, uint16(u))
-	check(t, `uint32="%d"`, us, uint32(u))
-	check(t, `uint64="%d"`, us, uint64(u))
-
-	const f = 3.141592
-	const fs = `3.141592`
-	check(t, `float64="%g"`, fs, f)
-	check(t, `float32="%g"`, fs, float32(f))
-	check(t, `float64="%g"`, fs, float64(f))
-}
-
-
-func TestArrayTypes(t *testing.T) {
-	var a0 [10]int
-	check(t, `array="array";`, `array`, a0)
-
-	a1 := [...]int{1, 2, 3}
-	check(t, `array="array";`, `array`, a1)
-	check(t, `array={*}; int="%d";`, `123`, a1)
-	check(t, `array={* / ", "}; int="%d";`, `1, 2, 3`, a1)
-	check(t, `array={* / *}; int="%d";`, `12233`, a1)
-
-	a2 := []interface{}{42, "foo", 3.14}
-	check(t, `array={* / ", "}; interface=*; string="bar"; default="%v";`, `42, bar, 3.14`, a2)
-}
-
-
-func TestChanTypes(t *testing.T) {
-	var c0 chan int
-	check(t, `chan="chan"`, `chan`, c0)
-
-	c1 := make(chan int)
-	go func() { c1 <- 42 }()
-	check(t, `chan="chan"`, `chan`, c1)
-	// check(t, `chan=*`, `42`, c1);  // reflection support for chans incomplete
-}
-
-
-func TestFuncTypes(t *testing.T) {
-	var f0 func() int
-	check(t, `func="func"`, `func`, f0)
-
-	f1 := func() int { return 42 }
-	check(t, `func="func"`, `func`, f1)
-	// check(t, `func=*`, `42`, f1);  // reflection support for funcs incomplete
-}
-
-
-func TestMapTypes(t *testing.T) {
-	var m0 map[string]int
-	check(t, `map="map"`, `map`, m0)
-
-	m1 := map[string]int{}
-	check(t, `map="map"`, `map`, m1)
-	// check(t, `map=*`, ``, m1);  // reflection support for maps incomplete
-}
-
-
-func TestPointerTypes(t *testing.T) {
-	var p0 *int
-	check(t, `ptr="ptr"`, `ptr`, p0)
-	check(t, `ptr=*`, ``, p0)
-	check(t, `ptr=*|"nil"`, `nil`, p0)
-
-	x := 99991
-	p1 := &x
-	check(t, `ptr="ptr"`, `ptr`, p1)
-	check(t, `ptr=*; int="%d"`, `99991`, p1)
-}
-
-
-func TestDefaultRule(t *testing.T) {
-	check(t, `default="%v"`, `42foo3.14`, 42, "foo", 3.14)
-	check(t, `default="%v"; int="%x"`, `abcdef`, 10, 11, 12, 13, 14, 15)
-	check(t, `default="%v"; int="%x"`, `ab**ef`, 10, 11, "**", 14, 15)
-	check(t, `default="%x"; int=@:default`, `abcdef`, 10, 11, 12, 13, 14, 15)
-}
-
-
-func TestGlobalSeparatorRule(t *testing.T) {
-	check(t, `int="%d"; / ="-"`, `1-2-3-4`, 1, 2, 3, 4)
-	check(t, `int="%x%x"; / ="*"`, `aa*aa`, 10, 10)
-}
-
-
-// ----------------------------------------------------------------------------
-// Formatting of a struct
-
-type T1 struct {
-	a int
-}
-
-const F1 = `datafmt "datafmt";` +
-	`int = "%d";` +
-	`datafmt.T1 = "<" a ">";`
-
-func TestStruct1(t *testing.T) { check(t, F1, "<42>", T1{42}) }
-
-
-// ----------------------------------------------------------------------------
-// Formatting of a struct with an optional field (ptr)
-
-type T2 struct {
-	s string
-	p *T1
-}
-
-const F2a = F1 +
-	`string = "%s";` +
-	`ptr = *;` +
-	`datafmt.T2 = s ["-" p "-"];`
-
-const F2b = F1 +
-	`string = "%s";` +
-	`ptr = *;` +
-	`datafmt.T2 = s ("-" p "-" | "empty");`
-
-func TestStruct2(t *testing.T) {
-	check(t, F2a, "foo", T2{"foo", nil})
-	check(t, F2a, "bar-<17>-", T2{"bar", &T1{17}})
-	check(t, F2b, "fooempty", T2{"foo", nil})
-}
-
-
-// ----------------------------------------------------------------------------
-// Formatting of a struct with a repetitive field (slice)
-
-type T3 struct {
-	s string
-	a []int
-}
-
-const F3a = `datafmt "datafmt";` +
-	`default = "%v";` +
-	`array = *;` +
-	`datafmt.T3 = s  {" " a a / ","};`
-
-const F3b = `datafmt "datafmt";` +
-	`int = "%d";` +
-	`string = "%s";` +
-	`array = *;` +
-	`nil = ;` +
-	`empty = *:nil;` +
-	`datafmt.T3 = s [a:empty ": " {a / "-"}]`
-
-func TestStruct3(t *testing.T) {
-	check(t, F3a, "foo", T3{"foo", nil})
-	check(t, F3a, "foo 00, 11, 22", T3{"foo", []int{0, 1, 2}})
-	check(t, F3b, "bar", T3{"bar", nil})
-	check(t, F3b, "bal: 2-3-5", T3{"bal", []int{2, 3, 5}})
-}
-
-
-// ----------------------------------------------------------------------------
-// Formatting of a struct with alternative field
-
-type T4 struct {
-	x *int
-	a []int
-}
-
-const F4a = `datafmt "datafmt";` +
-	`int = "%d";` +
-	`ptr = *;` +
-	`array = *;` +
-	`nil = ;` +
-	`empty = *:nil;` +
-	`datafmt.T4 = "<" (x:empty x | "-") ">" `
-
-const F4b = `datafmt "datafmt";` +
-	`int = "%d";` +
-	`ptr = *;` +
-	`array = *;` +
-	`nil = ;` +
-	`empty = *:nil;` +
-	`datafmt.T4 = "<" (a:empty {a / ", "} | "-") ">" `
-
-func TestStruct4(t *testing.T) {
-	x := 7
-	check(t, F4a, "<->", T4{nil, nil})
-	check(t, F4a, "<7>", T4{&x, nil})
-	check(t, F4b, "<->", T4{nil, nil})
-	check(t, F4b, "<2, 3, 7>", T4{nil, []int{2, 3, 7}})
-}
-
-
-// ----------------------------------------------------------------------------
-// Formatting a struct (documentation example)
-
-type Point struct {
-	name string
-	x, y int
-}
-
-const FPoint = `datafmt "datafmt";` +
-	`int = "%d";` +
-	`hexInt = "0x%x";` +
-	`string = "---%s---";` +
-	`datafmt.Point = name "{" x ", " y:hexInt "}";`
-
-func TestStructPoint(t *testing.T) {
-	p := Point{"foo", 3, 15}
-	check(t, FPoint, "---foo---{3, 0xf}", p)
-}
-
-
-// ----------------------------------------------------------------------------
-// Formatting a slice (documentation example)
-
-const FSlice = `int = "%b";` +
-	`array = { * / ", " }`
-
-func TestSlice(t *testing.T) { check(t, FSlice, "10, 11, 101, 111", []int{2, 3, 5, 7}) }
-
-
-// TODO add more tests

src/pkg/exp/datafmt/parser.go

@@ -1,386 +0,0 @@
-// Copyright 2009 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 datafmt
-
-import (
-	"container/vector"
-	"go/scanner"
-	"go/token"
-	"os"
-	"strconv"
-	"strings"
-)
-
-// ----------------------------------------------------------------------------
-// Parsing
-
-type parser struct {
-	scanner.ErrorVector
-	scanner scanner.Scanner
-	file    *token.File
-	pos     token.Pos   // token position
-	tok     token.Token // one token look-ahead
-	lit     string      // token literal
-
-	packs map[string]string // PackageName -> ImportPath
-	rules map[string]expr   // RuleName -> Expression
-}
-
-
-func (p *parser) next() {
-	p.pos, p.tok, p.lit = p.scanner.Scan()
-	switch p.tok {
-	case token.CHAN, token.FUNC, token.INTERFACE, token.MAP, token.STRUCT:
-		// Go keywords for composite types are type names
-		// returned by reflect. Accept them as identifiers.
-		p.tok = token.IDENT // p.lit is already set correctly
-	}
-}
-
-
-func (p *parser) init(fset *token.FileSet, filename string, src []byte) {
-	p.ErrorVector.Reset()
-	p.file = fset.AddFile(filename, fset.Base(), len(src))
-	p.scanner.Init(p.file, src, p, scanner.AllowIllegalChars) // return '@' as token.ILLEGAL w/o error message
-	p.next()                                                  // initializes pos, tok, lit
-	p.packs = make(map[string]string)
-	p.rules = make(map[string]expr)
-}
-
-
-func (p *parser) error(pos token.Pos, msg string) {
-	p.Error(p.file.Position(pos), msg)
-}
-
-
-func (p *parser) errorExpected(pos token.Pos, msg string) {
-	msg = "expected " + msg
-	if pos == p.pos {
-		// the error happened at the current position;
-		// make the error message more specific
-		msg += ", found '" + p.tok.String() + "'"
-		if p.tok.IsLiteral() {
-			msg += " " + p.lit
-		}
-	}
-	p.error(pos, msg)
-}
-
-
-func (p *parser) expect(tok token.Token) token.Pos {
-	pos := p.pos
-	if p.tok != tok {
-		p.errorExpected(pos, "'"+tok.String()+"'")
-	}
-	p.next() // make progress in any case
-	return pos
-}
-
-
-func (p *parser) parseIdentifier() string {
-	name := p.lit
-	p.expect(token.IDENT)
-	return name
-}
-
-
-func (p *parser) parseTypeName() (string, bool) {
-	pos := p.pos
-	name, isIdent := p.parseIdentifier(), true
-	if p.tok == token.PERIOD {
-		// got a package name, lookup package
-		if importPath, found := p.packs[name]; found {
-			name = importPath
-		} else {
-			p.error(pos, "package not declared: "+name)
-		}
-		p.next()
-		name, isIdent = name+"."+p.parseIdentifier(), false
-	}
-	return name, isIdent
-}
-
-
-// Parses a rule name and returns it. If the rule name is
-// a package-qualified type name, the package name is resolved.
-// The 2nd result value is true iff the rule name consists of a
-// single identifier only (and thus could be a package name).
-//
-func (p *parser) parseRuleName() (string, bool) {
-	name, isIdent := "", false
-	switch p.tok {
-	case token.IDENT:
-		name, isIdent = p.parseTypeName()
-	case token.DEFAULT:
-		name = "default"
-		p.next()
-	case token.QUO:
-		name = "/"
-		p.next()
-	default:
-		p.errorExpected(p.pos, "rule name")
-		p.next() // make progress in any case
-	}
-	return name, isIdent
-}
-
-
-func (p *parser) parseString() string {
-	s := ""
-	if p.tok == token.STRING {
-		s, _ = strconv.Unquote(p.lit)
-		// Unquote may fail with an error, but only if the scanner found
-		// an illegal string in the first place. In this case the error
-		// has already been reported.
-		p.next()
-		return s
-	} else {
-		p.expect(token.STRING)
-	}
-	return s
-}
-
-
-func (p *parser) parseLiteral() literal {
-	s := []byte(p.parseString())
-
-	// A string literal may contain %-format specifiers. To simplify
-	// and speed up printing of the literal, split it into segments
-	// that start with "%" possibly followed by a last segment that
-	// starts with some other character.
-	var list vector.Vector
-	i0 := 0
-	for i := 0; i < len(s); i++ {
-		if s[i] == '%' && i+1 < len(s) {
-			// the next segment starts with a % format
-			if i0 < i {
-				// the current segment is not empty, split it off
-				list.Push(s[i0:i])
-				i0 = i
-			}
-			i++ // skip %; let loop skip over char after %
-		}
-	}
-	// the final segment may start with any character
-	// (it is empty iff the string is empty)
-	list.Push(s[i0:])
-
-	// convert list into a literal
-	lit := make(literal, list.Len())
-	for i := 0; i < list.Len(); i++ {
-		lit[i] = list.At(i).([]byte)
-	}
-
-	return lit
-}
-
-
-func (p *parser) parseField() expr {
-	var fname string
-	switch p.tok {
-	case token.ILLEGAL:
-		if p.lit != "@" {
-			return nil
-		}
-		fname = "@"
-		p.next()
-	case token.MUL:
-		fname = "*"
-		p.next()
-	case token.IDENT:
-		fname = p.parseIdentifier()
-	default:
-		return nil
-	}
-
-	var ruleName string
-	if p.tok == token.COLON {
-		p.next()
-		ruleName, _ = p.parseRuleName()
-	}
-
-	return &field{fname, ruleName}
-}
-
-
-func (p *parser) parseOperand() (x expr) {
-	switch p.tok {
-	case token.STRING:
-		x = p.parseLiteral()
-
-	case token.LPAREN:
-		p.next()
-		x = p.parseExpression()
-		if p.tok == token.SHR {
-			p.next()
-			x = &group{x, p.parseExpression()}
-		}
-		p.expect(token.RPAREN)
-
-	case token.LBRACK:
-		p.next()
-		x = &option{p.parseExpression()}
-		p.expect(token.RBRACK)
-
-	case token.LBRACE:
-		p.next()
-		x = p.parseExpression()
-		var div expr
-		if p.tok == token.QUO {
-			p.next()
-			div = p.parseExpression()
-		}
-		x = &repetition{x, div}
-		p.expect(token.RBRACE)
-
-	default:
-		x = p.parseField() // may be nil
-	}
-
-	return x
-}
-
-
-func (p *parser) parseSequence() expr {
-	var list vector.Vector
-
-	for x := p.parseOperand(); x != nil; x = p.parseOperand() {
-		list.Push(x)
-	}
-
-	// no need for a sequence if list.Len() < 2
-	switch list.Len() {
-	case 0:
-		return nil
-	case 1:
-		return list.At(0).(expr)
-	}
-
-	// convert list into a sequence
-	seq := make(sequence, list.Len())
-	for i := 0; i < list.Len(); i++ {
-		seq[i] = list.At(i).(expr)
-	}
-	return seq
-}
-
-
-func (p *parser) parseExpression() expr {
-	var list vector.Vector
-
-	for {
-		x := p.parseSequence()
-		if x != nil {
-			list.Push(x)
-		}
-		if p.tok != token.OR {
-			break
-		}
-		p.next()
-	}
-
-	// no need for an alternatives if list.Len() < 2
-	switch list.Len() {
-	case 0:
-		return nil
-	case 1:
-		return list.At(0).(expr)
-	}
-
-	// convert list into a alternatives
-	alt := make(alternatives, list.Len())
-	for i := 0; i < list.Len(); i++ {
-		alt[i] = list.At(i).(expr)
-	}
-	return alt
-}
-
-
-func (p *parser) parseFormat() {
-	for p.tok != token.EOF {
-		pos := p.pos
-
-		name, isIdent := p.parseRuleName()
-		switch p.tok {
-		case token.STRING:
-			// package declaration
-			importPath := p.parseString()
-
-			// add package declaration
-			if !isIdent {
-				p.error(pos, "illegal package name: "+name)
-			} else if _, found := p.packs[name]; !found {
-				p.packs[name] = importPath
-			} else {
-				p.error(pos, "package already declared: "+name)
-			}
-
-		case token.ASSIGN:
-			// format rule
-			p.next()
-			x := p.parseExpression()
-
-			// add rule
-			if _, found := p.rules[name]; !found {
-				p.rules[name] = x
-			} else {
-				p.error(pos, "format rule already declared: "+name)
-			}
-
-		default:
-			p.errorExpected(p.pos, "package declaration or format rule")
-			p.next() // make progress in any case
-		}
-
-		if p.tok == token.SEMICOLON {
-			p.next()
-		} else {
-			break
-		}
-	}
-	p.expect(token.EOF)
-}
-
-
-func remap(p *parser, name string) string {
-	i := strings.Index(name, ".")
-	if i >= 0 {
-		packageName, suffix := name[0:i], name[i:]
-		// lookup package
-		if importPath, found := p.packs[packageName]; found {
-			name = importPath + suffix
-		} else {
-			var invalidPos token.Position
-			p.Error(invalidPos, "package not declared: "+packageName)
-		}
-	}
-	return name
-}
-
-
-// Parse parses a set of format productions from source src. Custom
-// formatters may be provided via a map of formatter functions. If
-// there are no errors, the result is a Format and the error is nil.
-// Otherwise the format is nil and a non-empty ErrorList is returned.
-//
-func Parse(fset *token.FileSet, filename string, src []byte, fmap FormatterMap) (Format, os.Error) {
-	// parse source
-	var p parser
-	p.init(fset, filename, src)
-	p.parseFormat()
-
-	// add custom formatters, if any
-	for name, form := range fmap {
-		name = remap(&p, name)
-		if _, found := p.rules[name]; !found {
-			p.rules[name] = &custom{name, form}
-		} else {
-			var invalidPos token.Position
-			p.Error(invalidPos, "formatter already declared: "+name)
-		}
-	}
-
-	return p.rules, p.GetError(scanner.NoMultiples)
-}

src/pkg/fmt/fmt_test.go

@@ -62,7 +62,7 @@ type I int
 func (i I) String() string { return Sprintf("<%d>", int(i)) }
 
 type B struct {
-	i I
+	I I
 	j int
 }
 
@@ -84,8 +84,8 @@ func (g G) GoString() string {
 }
 
 type S struct {
-	f F // a struct field that Formats
-	g G // a struct field that GoStrings
+	F F // a struct field that Formats
+	G G // a struct field that GoStrings
 }
 
 // A type with a String method with pointer receiver for testing %p
@@ -322,8 +322,8 @@ var fmttests = []struct {
 	{"%+v", A{1, 2, "a", []int{1, 2}}, `{i:1 j:2 s:a x:[1 2]}`},
 
 	// +v on structs with Stringable items
-	{"%+v", B{1, 2}, `{i:<1> j:2}`},
-	{"%+v", C{1, B{2, 3}}, `{i:1 B:{i:<2> j:3}}`},
+	{"%+v", B{1, 2}, `{I:<1> j:2}`},
+	{"%+v", C{1, B{2, 3}}, `{i:1 B:{I:<2> j:3}}`},
 
 	// q on Stringable items
 	{"%s", I(23), `<23>`},
@@ -339,7 +339,7 @@ var fmttests = []struct {
 	{"%#v", uint64(1<<64 - 1), "0xffffffffffffffff"},
 	{"%#v", 1000000000, "1000000000"},
 	{"%#v", map[string]int{"a": 1, "b": 2}, `map[string] int{"a":1, "b":2}`},
-	{"%#v", map[string]B{"a": {1, 2}, "b": {3, 4}}, `map[string] fmt_test.B{"a":fmt_test.B{i:1, j:2}, "b":fmt_test.B{i:3, j:4}}`},
+	{"%#v", map[string]B{"a": {1, 2}, "b": {3, 4}}, `map[string] fmt_test.B{"a":fmt_test.B{I:1, j:2}, "b":fmt_test.B{I:3, j:4}}`},
 	{"%#v", []string{"a", "b"}, `[]string{"a", "b"}`},
 
 	// slices with other formats
@@ -374,11 +374,11 @@ var fmttests = []struct {
 	// Formatter
 	{"%x", F(1), "<x=F(1)>"},
 	{"%x", G(2), "2"},
-	{"%+v", S{F(4), G(5)}, "{f:<v=F(4)> g:5}"},
+	{"%+v", S{F(4), G(5)}, "{F:<v=F(4)> G:5}"},
 
 	// GoStringer
 	{"%#v", G(6), "GoString(6)"},
-	{"%#v", S{F(7), G(8)}, "fmt_test.S{f:<v=F(7)>, g:GoString(8)}"},
+	{"%#v", S{F(7), G(8)}, "fmt_test.S{F:<v=F(7)>, G:GoString(8)}"},
 
 	// %T
 	{"%T", (4 - 3i), "complex128"},

src/pkg/fmt/print.go

@@ -259,10 +259,8 @@ func Sprintln(a ...interface{}) string {
 // the thing inside the interface, not the interface itself.
 func getField(v reflect.Value, i int) reflect.Value {
 	val := v.Field(i)
-	if i := val; i.Kind() == reflect.Interface {
-		if inter := i.Interface(); inter != nil {
-			return reflect.ValueOf(inter)
-		}
+	if val.Kind() == reflect.Interface && !val.IsNil() {
+		val = val.Elem()
 	}
 	return val
 }
@@ -289,27 +287,32 @@ func (p *pp) unknownType(v interface{}) {
 	p.buf.WriteByte('?')
 }
 
-func (p *pp) badVerb(verb int, val interface{}) {
+func (p *pp) badVerb(verb int, val interface{}, val1 reflect.Value) {
 	p.add('%')
 	p.add('!')
 	p.add(verb)
 	p.add('(')
-	if val == nil {
-		p.buf.Write(nilAngleBytes)
-	} else {
+	switch {
+	case val != nil:
 		p.buf.WriteString(reflect.TypeOf(val).String())
 		p.add('=')
 		p.printField(val, 'v', false, false, 0)
+	case val1.IsValid():
+		p.buf.WriteString(val1.Type().String())
+		p.add('=')
+		p.printValue(val1, 'v', false, false, 0)
+	default:
+		p.buf.Write(nilAngleBytes)
 	}
 	p.add(')')
 }
 
-func (p *pp) fmtBool(v bool, verb int, value interface{}) {
+func (p *pp) fmtBool(v bool, verb int, value interface{}, value1 reflect.Value) {
 	switch verb {
 	case 't', 'v':
 		p.fmt.fmt_boolean(v)
 	default:
-		p.badVerb(verb, value)
+		p.badVerb(verb, value, value1)
 	}
 }
 
@@ -323,7 +326,7 @@ func (p *pp) fmtC(c int64) {
 	p.fmt.pad(p.runeBuf[0:w])
 }
 
-func (p *pp) fmtInt64(v int64, verb int, value interface{}) {
+func (p *pp) fmtInt64(v int64, verb int, value interface{}, value1 reflect.Value) {
 	switch verb {
 	case 'b':
 		p.fmt.integer(v, 2, signed, ldigits)
@@ -337,7 +340,7 @@ func (p *pp) fmtInt64(v int64, verb int, value interface{}) {
 		if 0 <= v && v <= unicode.MaxRune {
 			p.fmt.fmt_qc(v)
 		} else {
-			p.badVerb(verb, value)
+			p.badVerb(verb, value, value1)
 		}
 	case 'x':
 		p.fmt.integer(v, 16, signed, ldigits)
@@ -346,7 +349,7 @@ func (p *pp) fmtInt64(v int64, verb int, value interface{}) {
 	case 'X':
 		p.fmt.integer(v, 16, signed, udigits)
 	default:
-		p.badVerb(verb, value)
+		p.badVerb(verb, value, value1)
 	}
 }
 
@@ -376,7 +379,7 @@ func (p *pp) fmtUnicode(v int64) {
 	p.fmt.precPresent = precPresent
 }
 
-func (p *pp) fmtUint64(v uint64, verb int, goSyntax bool, value interface{}) {
+func (p *pp) fmtUint64(v uint64, verb int, goSyntax bool, value interface{}, value1 reflect.Value) {
 	switch verb {
 	case 'b':
 		p.fmt.integer(int64(v), 2, unsigned, ldigits)
@@ -396,7 +399,7 @@ func (p *pp) fmtUint64(v uint64, verb int, goSyntax bool, value interface{}) {
 		if 0 <= v && v <= unicode.MaxRune {
 			p.fmt.fmt_qc(int64(v))
 		} else {
-			p.badVerb(verb, value)
+			p.badVerb(verb, value, value1)
 		}
 	case 'x':
 		p.fmt.integer(int64(v), 16, unsigned, ldigits)
@@ -405,11 +408,11 @@ func (p *pp) fmtUint64(v uint64, verb int, goSyntax bool, value interface{}) {
 	case 'U':
 		p.fmtUnicode(int64(v))
 	default:
-		p.badVerb(verb, value)
+		p.badVerb(verb, value, value1)
 	}
 }
 
-func (p *pp) fmtFloat32(v float32, verb int, value interface{}) {
+func (p *pp) fmtFloat32(v float32, verb int, value interface{}, value1 reflect.Value) {
 	switch verb {
 	case 'b':
 		p.fmt.fmt_fb32(v)
@@ -424,11 +427,11 @@ func (p *pp) fmtFloat32(v float32, verb int, value interface{}) {
 	case 'G':
 		p.fmt.fmt_G32(v)
 	default:
-		p.badVerb(verb, value)
+		p.badVerb(verb, value, value1)
 	}
 }
 
-func (p *pp) fmtFloat64(v float64, verb int, value interface{}) {
+func (p *pp) fmtFloat64(v float64, verb int, value interface{}, value1 reflect.Value) {
 	switch verb {
 	case 'b':
 		p.fmt.fmt_fb64(v)
@@ -443,33 +446,33 @@ func (p *pp) fmtFloat64(v float64, verb int, value interface{}) {
 	case 'G':
 		p.fmt.fmt_G64(v)
 	default:
-		p.badVerb(verb, value)
+		p.badVerb(verb, value, value1)
 	}
 }
 
-func (p *pp) fmtComplex64(v complex64, verb int, value interface{}) {
+func (p *pp) fmtComplex64(v complex64, verb int, value interface{}, value1 reflect.Value) {
 	switch verb {
 	case 'e', 'E', 'f', 'F', 'g', 'G':
 		p.fmt.fmt_c64(v, verb)
 	case 'v':
 		p.fmt.fmt_c64(v, 'g')
 	default:
-		p.badVerb(verb, value)
+		p.badVerb(verb, value, value1)
 	}
 }
 
-func (p *pp) fmtComplex128(v complex128, verb int, value interface{}) {
+func (p *pp) fmtComplex128(v complex128, verb int, value interface{}, value1 reflect.Value) {
 	switch verb {
 	case 'e', 'E', 'f', 'F', 'g', 'G':
 		p.fmt.fmt_c128(v, verb)
 	case 'v':
 		p.fmt.fmt_c128(v, 'g')
 	default:
-		p.badVerb(verb, value)
+		p.badVerb(verb, value, value1)
 	}
 }
 
-func (p *pp) fmtString(v string, verb int, goSyntax bool, value interface{}) {
+func (p *pp) fmtString(v string, verb int, goSyntax bool, value interface{}, value1 reflect.Value) {
 	switch verb {
 	case 'v':
 		if goSyntax {
@@ -486,11 +489,11 @@ func (p *pp) fmtString(v string, verb int, goSyntax bool, value interface{}) {
 	case 'q':
 		p.fmt.fmt_q(v)
 	default:
-		p.badVerb(verb, value)
+		p.badVerb(verb, value, value1)
 	}
 }
 
-func (p *pp) fmtBytes(v []byte, verb int, goSyntax bool, depth int, value interface{}) {
+func (p *pp) fmtBytes(v []byte, verb int, goSyntax bool, depth int, value interface{}, value1 reflect.Value) {
 	if verb == 'v' || verb == 'd' {
 		if goSyntax {
 			p.buf.Write(bytesBytes)
@@ -525,7 +528,7 @@ func (p *pp) fmtBytes(v []byte, verb int, goSyntax bool, depth int, value interf
 	case 'q':
 		p.fmt.fmt_q(s)
 	default:
-		p.badVerb(verb, value)
+		p.badVerb(verb, value, value1)
 	}
 }
 
@@ -535,12 +538,12 @@ func (p *pp) fmtPointer(field interface{}, value reflect.Value, verb int, goSynt
 	case reflect.Chan, reflect.Func, reflect.Map, reflect.Ptr, reflect.Slice, reflect.UnsafePointer:
 		u = value.Pointer()
 	default:
-		p.badVerb(verb, field)
+		p.badVerb(verb, field, value)
 		return
 	}
 	if goSyntax {
 		p.add('(')
-		p.buf.WriteString(reflect.TypeOf(field).String())
+		p.buf.WriteString(value.Type().String())
 		p.add(')')
 		p.add('(')
 		if u == 0 {
@@ -561,12 +564,48 @@ var (
 	uintptrBits = reflect.TypeOf(uintptr(0)).Bits()
 )
 
+func (p *pp) handleMethods(field interface{}, verb int, plus, goSyntax bool, depth int) (wasString, handled bool) {
+	// Is it a Formatter?
+	if formatter, ok := field.(Formatter); ok {
+		handled = true
+		wasString = false
+		formatter.Format(p, verb)
+		return
+	}
+	// Must not touch flags before Formatter looks at them.
+	if plus {
+		p.fmt.plus = false
+	}
+
+	// If we're doing Go syntax and the field knows how to supply it, take care of it now.
+	if goSyntax {
+		p.fmt.sharp = false
+		if stringer, ok := field.(GoStringer); ok {
+			wasString = false
+			handled = true
+			// Print the result of GoString unadorned.
+			p.fmtString(stringer.GoString(), 's', false, field, reflect.Value{})
+			return
+		}
+	} else {
+		// Is it a Stringer?
+		if stringer, ok := field.(Stringer); ok {
+			wasString = false
+			handled = true
+			p.printField(stringer.String(), verb, plus, false, depth)
+			return
+		}
+	}
+	handled = false
+	return
+}
+
 func (p *pp) printField(field interface{}, verb int, plus, goSyntax bool, depth int) (wasString bool) {
 	if field == nil {
 		if verb == 'T' || verb == 'v' {
 			p.buf.Write(nilAngleBytes)
 		} else {
-			p.badVerb(verb, field)
+			p.badVerb(verb, field, reflect.Value{})
 		}
 		return false
 	}
@@ -581,115 +620,133 @@ func (p *pp) printField(field interface{}, verb int, plus, goSyntax bool, depth
 		p.fmtPointer(field, reflect.ValueOf(field), verb, goSyntax)
 		return false
 	}
-	// Is it a Formatter?
-	if formatter, ok := field.(Formatter); ok {
-		formatter.Format(p, verb)
-		return false // this value is not a string
 
-	}
-	// Must not touch flags before Formatter looks at them.
-	if plus {
-		p.fmt.plus = false
-	}
-	// If we're doing Go syntax and the field knows how to supply it, take care of it now.
-	if goSyntax {
-		p.fmt.sharp = false
-		if stringer, ok := field.(GoStringer); ok {
-			// Print the result of GoString unadorned.
-			p.fmtString(stringer.GoString(), 's', false, field)
-			return false // this value is not a string
-		}
-	} else {
-		// Is it a Stringer?
-		if stringer, ok := field.(Stringer); ok {
-			p.printField(stringer.String(), verb, plus, false, depth)
-			return false // this value is not a string
-		}
+	if wasString, handled := p.handleMethods(field, verb, plus, goSyntax, depth); handled {
+		return wasString
 	}
 
 	// Some types can be done without reflection.
 	switch f := field.(type) {
 	case bool:
-		p.fmtBool(f, verb, field)
+		p.fmtBool(f, verb, field, reflect.Value{})
 		return false
 	case float32:
-		p.fmtFloat32(f, verb, field)
+		p.fmtFloat32(f, verb, field, reflect.Value{})
 		return false
 	case float64:
-		p.fmtFloat64(f, verb, field)
+		p.fmtFloat64(f, verb, field, reflect.Value{})
 		return false
 	case complex64:
-		p.fmtComplex64(complex64(f), verb, field)
+		p.fmtComplex64(complex64(f), verb, field, reflect.Value{})
 		return false
 	case complex128:
-		p.fmtComplex128(f, verb, field)
+		p.fmtComplex128(f, verb, field, reflect.Value{})
 		return false
 	case int:
-		p.fmtInt64(int64(f), verb, field)
+		p.fmtInt64(int64(f), verb, field, reflect.Value{})
 		return false
 	case int8:
-		p.fmtInt64(int64(f), verb, field)
+		p.fmtInt64(int64(f), verb, field, reflect.Value{})
 		return false
 	case int16:
-		p.fmtInt64(int64(f), verb, field)
+		p.fmtInt64(int64(f), verb, field, reflect.Value{})
 		return false
 	case int32:
-		p.fmtInt64(int64(f), verb, field)
+		p.fmtInt64(int64(f), verb, field, reflect.Value{})
 		return false
 	case int64:
-		p.fmtInt64(f, verb, field)
+		p.fmtInt64(f, verb, field, reflect.Value{})
 		return false
 	case uint:
-		p.fmtUint64(uint64(f), verb, goSyntax, field)
+		p.fmtUint64(uint64(f), verb, goSyntax, field, reflect.Value{})
 		return false
 	case uint8:
-		p.fmtUint64(uint64(f), verb, goSyntax, field)
+		p.fmtUint64(uint64(f), verb, goSyntax, field, reflect.Value{})
 		return false
 	case uint16:
-		p.fmtUint64(uint64(f), verb, goSyntax, field)
+		p.fmtUint64(uint64(f), verb, goSyntax, field, reflect.Value{})
 		return false
 	case uint32:
-		p.fmtUint64(uint64(f), verb, goSyntax, field)
+		p.fmtUint64(uint64(f), verb, goSyntax, field, reflect.Value{})
 		return false
 	case uint64:
-		p.fmtUint64(f, verb, goSyntax, field)
+		p.fmtUint64(f, verb, goSyntax, field, reflect.Value{})
 		return false
 	case uintptr:
-		p.fmtUint64(uint64(f), verb, goSyntax, field)
+		p.fmtUint64(uint64(f), verb, goSyntax, field, reflect.Value{})
 		return false
 	case string:
-		p.fmtString(f, verb, goSyntax, field)
+		p.fmtString(f, verb, goSyntax, field, reflect.Value{})
 		return verb == 's' || verb == 'v'
 	case []byte:
-		p.fmtBytes(f, verb, goSyntax, depth, field)
+		p.fmtBytes(f, verb, goSyntax, depth, field, reflect.Value{})
 		return verb == 's'
 	}
 
 	// Need to use reflection
-	value := reflect.ValueOf(field)
+	return p.printReflectValue(reflect.ValueOf(field), verb, plus, goSyntax, depth)
+}
 
+// printValue is like printField but starts with a reflect value, not an interface{} value.
+func (p *pp) printValue(value reflect.Value, verb int, plus, goSyntax bool, depth int) (wasString bool) {
+	if !value.IsValid() {
+		if verb == 'T' || verb == 'v' {
+			p.buf.Write(nilAngleBytes)
+		} else {
+			p.badVerb(verb, nil, value)
+		}
+		return false
+	}
+
+	// Special processing considerations.
+	// %T (the value's type) and %p (its address) are special; we always do them first.
+	switch verb {
+	case 'T':
+		p.printField(value.Type().String(), 's', false, false, 0)
+		return false
+	case 'p':
+		p.fmtPointer(nil, value, verb, goSyntax)
+		return false
+	}
+
+	// Handle values with special methods.
+	// Call always, even when field == nil, because handleMethods clears p.fmt.plus for us.
+	var field interface{}
+	if value.CanInterface() {
+		field = value.Interface()
+	}
+	if wasString, handled := p.handleMethods(field, verb, plus, goSyntax, depth); handled {
+		return wasString
+	}
+
+	return p.printReflectValue(value, verb, plus, goSyntax, depth)
+}
+
+// printReflectValue is the fallback for both printField and printValue.
+// It uses reflect to print the value.
+func (p *pp) printReflectValue(value reflect.Value, verb int, plus, goSyntax bool, depth int) (wasString bool) {
 BigSwitch:
 	switch f := value; f.Kind() {
 	case reflect.Bool:
-		p.fmtBool(f.Bool(), verb, field)
+		p.fmtBool(f.Bool(), verb, nil, value)
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		p.fmtInt64(f.Int(), verb, field)
+		p.fmtInt64(f.Int(), verb, nil, value)
 	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-		p.fmtUint64(uint64(f.Uint()), verb, goSyntax, field)
+		p.fmtUint64(uint64(f.Uint()), verb, goSyntax, nil, value)
 	case reflect.Float32, reflect.Float64:
 		if f.Type().Size() == 4 {
-			p.fmtFloat32(float32(f.Float()), verb, field)
+			p.fmtFloat32(float32(f.Float()), verb, nil, value)
 		} else {
-			p.fmtFloat64(float64(f.Float()), verb, field)
+			p.fmtFloat64(float64(f.Float()), verb, nil, value)
 		}
 	case reflect.Complex64, reflect.Complex128:
 		if f.Type().Size() == 8 {
-			p.fmtComplex64(complex64(f.Complex()), verb, field)
+			p.fmtComplex64(complex64(f.Complex()), verb, nil, value)
 		} else {
-			p.fmtComplex128(complex128(f.Complex()), verb, field)
+			p.fmtComplex128(complex128(f.Complex()), verb, nil, value)
 		}
 	case reflect.String:
-		p.fmtString(f.String(), verb, goSyntax, field)
+		p.fmtString(f.String(), verb, goSyntax, nil, value)
 	case reflect.Map:
 		if goSyntax {
 			p.buf.WriteString(f.Type().String())
@@ -706,9 +763,9 @@ BigSwitch:
 					p.buf.WriteByte(' ')
 				}
 			}
-			p.printField(key.Interface(), verb, plus, goSyntax, depth+1)
+			p.printValue(key, verb, plus, goSyntax, depth+1)
 			p.buf.WriteByte(':')
-			p.printField(f.MapIndex(key).Interface(), verb, plus, goSyntax, depth+1)
+			p.printValue(f.MapIndex(key), verb, plus, goSyntax, depth+1)
 		}
 		if goSyntax {
 			p.buf.WriteByte('}')
@@ -717,7 +774,7 @@ BigSwitch:
 		}
 	case reflect.Struct:
 		if goSyntax {
-			p.buf.WriteString(reflect.TypeOf(field).String())
+			p.buf.WriteString(value.Type().String())
 		}
 		p.add('{')
 		v := f
@@ -736,20 +793,20 @@ BigSwitch:
 					p.buf.WriteByte(':')
 				}
 			}
-			p.printField(getField(v, i).Interface(), verb, plus, goSyntax, depth+1)
+			p.printValue(getField(v, i), verb, plus, goSyntax, depth+1)
 		}
 		p.buf.WriteByte('}')
 	case reflect.Interface:
 		value := f.Elem()
 		if !value.IsValid() {
 			if goSyntax {
-				p.buf.WriteString(reflect.TypeOf(field).String())
+				p.buf.WriteString(value.Type().String())
 				p.buf.Write(nilParenBytes)
 			} else {
 				p.buf.Write(nilAngleBytes)
 			}
 		} else {
-			return p.printField(value.Interface(), verb, plus, goSyntax, depth+1)
+			return p.printValue(value, verb, plus, goSyntax, depth+1)
 		}
 	case reflect.Array, reflect.Slice:
 		// Byte slices are special.
@@ -765,11 +822,11 @@ BigSwitch:
 			for i := range bytes {
 				bytes[i] = byte(f.Index(i).Uint())
 			}
-			p.fmtBytes(bytes, verb, goSyntax, depth, field)
+			p.fmtBytes(bytes, verb, goSyntax, depth, nil, value)
 			return verb == 's'
 		}
 		if goSyntax {
-			p.buf.WriteString(reflect.TypeOf(field).String())
+			p.buf.WriteString(value.Type().String())
 			p.buf.WriteByte('{')
 		} else {
 			p.buf.WriteByte('[')
@@ -782,7 +839,7 @@ BigSwitch:
 					p.buf.WriteByte(' ')
 				}
 			}
-			p.printField(f.Index(i).Interface(), verb, plus, goSyntax, depth+1)
+			p.printValue(f.Index(i), verb, plus, goSyntax, depth+1)
 		}
 		if goSyntax {
 			p.buf.WriteByte('}')
@@ -797,17 +854,17 @@ BigSwitch:
 			switch a := f.Elem(); a.Kind() {
 			case reflect.Array, reflect.Slice:
 				p.buf.WriteByte('&')
-				p.printField(a.Interface(), verb, plus, goSyntax, depth+1)
+				p.printValue(a, verb, plus, goSyntax, depth+1)
 				break BigSwitch
 			case reflect.Struct:
 				p.buf.WriteByte('&')
-				p.printField(a.Interface(), verb, plus, goSyntax, depth+1)
+				p.printValue(a, verb, plus, goSyntax, depth+1)
 				break BigSwitch
 			}
 		}
 		if goSyntax {
 			p.buf.WriteByte('(')
-			p.buf.WriteString(reflect.TypeOf(field).String())
+			p.buf.WriteString(value.Type().String())
 			p.buf.WriteByte(')')
 			p.buf.WriteByte('(')
 			if v == 0 {
@@ -824,7 +881,7 @@ BigSwitch:
 		}
 		p.fmt0x64(uint64(v), true)
 	case reflect.Chan, reflect.Func, reflect.UnsafePointer:
-		p.fmtPointer(field, value, verb, goSyntax)
+		p.fmtPointer(nil, value, verb, goSyntax)
 	default:
 		p.unknownType(f)
 	}

src/pkg/reflect/all_test.go

@@ -855,13 +855,13 @@ func TestIsNil(t *testing.T) {
 
 func TestInterfaceExtraction(t *testing.T) {
 	var s struct {
-		w io.Writer
+		W io.Writer
 	}
 
-	s.w = os.Stdout
+	s.W = os.Stdout
 	v := Indirect(ValueOf(&s)).Field(0).Interface()
-	if v != s.w.(interface{}) {
-		t.Error("Interface() on interface: ", v, s.w)
+	if v != s.W.(interface{}) {
+		t.Error("Interface() on interface: ", v, s.W)
 	}
 }
 
@@ -1156,18 +1156,18 @@ type D2 struct {
 }
 
 type S0 struct {
-	a, b, c int
+	A, B, C int
 	D1
 	D2
 }
 
 type S1 struct {
-	b int
+	B int
 	S0
 }
 
 type S2 struct {
-	a int
+	A int
 	*S1
 }
 
@@ -1182,36 +1182,36 @@ type S1y struct {
 type S3 struct {
 	S1x
 	S2
-	d, e int
+	D, E int
 	*S1y
 }
 
 type S4 struct {
 	*S4
-	a int
+	A int
 }
 
 var fieldTests = []FTest{
 	{struct{}{}, "", nil, 0},
-	{struct{}{}, "foo", nil, 0},
-	{S0{a: 'a'}, "a", []int{0}, 'a'},
-	{S0{}, "d", nil, 0},
-	{S1{S0: S0{a: 'a'}}, "a", []int{1, 0}, 'a'},
-	{S1{b: 'b'}, "b", []int{0}, 'b'},
+	{struct{}{}, "Foo", nil, 0},
+	{S0{A: 'a'}, "A", []int{0}, 'a'},
+	{S0{}, "D", nil, 0},
+	{S1{S0: S0{A: 'a'}}, "A", []int{1, 0}, 'a'},
+	{S1{B: 'b'}, "B", []int{0}, 'b'},
 	{S1{}, "S0", []int{1}, 0},
-	{S1{S0: S0{c: 'c'}}, "c", []int{1, 2}, 'c'},
-	{S2{a: 'a'}, "a", []int{0}, 'a'},
+	{S1{S0: S0{C: 'c'}}, "C", []int{1, 2}, 'c'},
+	{S2{A: 'a'}, "A", []int{0}, 'a'},
 	{S2{}, "S1", []int{1}, 0},
-	{S2{S1: &S1{b: 'b'}}, "b", []int{1, 0}, 'b'},
-	{S2{S1: &S1{S0: S0{c: 'c'}}}, "c", []int{1, 1, 2}, 'c'},
-	{S2{}, "d", nil, 0},
+	{S2{S1: &S1{B: 'b'}}, "B", []int{1, 0}, 'b'},
+	{S2{S1: &S1{S0: S0{C: 'c'}}}, "C", []int{1, 1, 2}, 'c'},
+	{S2{}, "D", nil, 0},
 	{S3{}, "S1", nil, 0},
-	{S3{S2: S2{a: 'a'}}, "a", []int{1, 0}, 'a'},
-	{S3{}, "b", nil, 0},
-	{S3{d: 'd'}, "d", []int{2}, 0},
-	{S3{e: 'e'}, "e", []int{3}, 'e'},
-	{S4{a: 'a'}, "a", []int{1}, 'a'},
-	{S4{}, "b", nil, 0},
+	{S3{S2: S2{A: 'a'}}, "A", []int{1, 0}, 'a'},
+	{S3{}, "B", nil, 0},
+	{S3{D: 'd'}, "D", []int{2}, 0},
+	{S3{E: 'e'}, "E", []int{3}, 'e'},
+	{S4{A: 'a'}, "A", []int{1}, 'a'},
+	{S4{}, "B", nil, 0},
 }
 
 func TestFieldByIndex(t *testing.T) {
@@ -1508,3 +1508,68 @@ func TestVariadic(t *testing.T) {
 		t.Errorf("after Fprintf CallSlice: %q != %q", b.String(), "hello 42 world")
 	}
 }
+
+type Private struct {
+	x int
+	y **int
+}
+
+func (p *Private) m() {
+}
+
+type Public struct {
+	X int
+	Y **int
+}
+
+func (p *Public) M() {
+}
+
+func TestUnexported(t *testing.T) {
+	var pub Public
+	v := ValueOf(&pub)
+	isValid(v.Elem().Field(0))
+	isValid(v.Elem().Field(1))
+	isValid(v.Elem().FieldByName("X"))
+	isValid(v.Elem().FieldByName("Y"))
+	isValid(v.Type().Method(0).Func)
+	isNonNil(v.Elem().Field(0).Interface())
+	isNonNil(v.Elem().Field(1).Interface())
+	isNonNil(v.Elem().FieldByName("X").Interface())
+	isNonNil(v.Elem().FieldByName("Y").Interface())
+	isNonNil(v.Type().Method(0).Func.Interface())
+
+	var priv Private
+	v = ValueOf(&priv)
+	isValid(v.Elem().Field(0))
+	isValid(v.Elem().Field(1))
+	isValid(v.Elem().FieldByName("x"))
+	isValid(v.Elem().FieldByName("y"))
+	isValid(v.Type().Method(0).Func)
+	shouldPanic(func() { v.Elem().Field(0).Interface() })
+	shouldPanic(func() { v.Elem().Field(1).Interface() })
+	shouldPanic(func() { v.Elem().FieldByName("x").Interface() })
+	shouldPanic(func() { v.Elem().FieldByName("y").Interface() })
+	shouldPanic(func() { v.Type().Method(0).Func.Interface() })
+}
+
+func shouldPanic(f func()) {
+	defer func() {
+		if recover() == nil {
+			panic("did not panic")
+		}
+	}()
+	f()
+}
+
+func isNonNil(x interface{}) {
+	if x == nil {
+		panic("nil interface")
+	}
+}
+
+func isValid(v Value) {
+	if !v.IsValid() {
+		panic("zero Value")
+	}
+}

src/pkg/reflect/deepequal.go

@@ -104,7 +104,7 @@ func deepValueEqual(v1, v2 Value, visited map[uintptr]*visit, depth int) (b bool
 		return true
 	default:
 		// Normal equality suffices
-		return v1.Interface() == v2.Interface()
+		return valueInterface(v1, false) == valueInterface(v2, false)
 	}
 
 	panic("Not reached")

src/pkg/reflect/value.go

@@ -841,14 +841,7 @@ func (v Value) CanInterface() bool {
 	if iv.kind == Invalid {
 		panic(&ValueError{"reflect.Value.CanInterface", iv.kind})
 	}
-	// TODO(rsc): Check flagRO too.  Decide what to do about asking for
-	// interface for a value obtained via an unexported field.
-	// If the field were of a known type, say chan int or *sync.Mutex,
-	// the caller could interfere with the data after getting the
-	// interface.  But fmt.Print depends on being able to look.
-	// Now that reflect is more efficient the special cases in fmt
-	// might be less important.
-	return v.InternalMethod == 0
+	return v.InternalMethod == 0 && iv.flag&flagRO == 0
 }
 
 // Interface returns v's value as an interface{}.
@@ -856,19 +849,25 @@ func (v Value) CanInterface() bool {
 // (as opposed to Type.Method), Interface cannot return an
 // interface value, so it panics.
 func (v Value) Interface() interface{} {
-	return v.internal().Interface()
+	return valueInterface(v, true)
 }
 
-func (iv internalValue) Interface() interface{} {
+func valueInterface(v Value, safe bool) interface{} {
+	iv := v.internal()
+	return iv.valueInterface(safe)
+}
+
+func (iv internalValue) valueInterface(safe bool) interface{} {
 	if iv.method {
 		panic("reflect.Value.Interface: cannot create interface value for method with bound receiver")
 	}
-	/*
-		if v.flag()&noExport != 0 {
-			panic("reflect.Value.Interface: cannot return value obtained from unexported struct field")
-		}
-	*/
 
+	if safe && iv.flag&flagRO != 0 {
+		// Do not allow access to unexported values via Interface,
+		// because they might be pointers that should not be 
+		// writable or methods or function that should not be callable.
+		panic("reflect.Value.Interface: cannot return value obtained from unexported field or method")
+	}
 	if iv.kind == Interface {
 		// Special case: return the element inside the interface.
 		// Won't recurse further because an interface cannot contain an interface.
@@ -1669,7 +1668,7 @@ func convertForAssignment(what string, addr unsafe.Pointer, dst Type, iv interna
 		if addr == nil {
 			addr = unsafe.Pointer(new(interface{}))
 		}
-		x := iv.Interface()
+		x := iv.valueInterface(false)
 		if dst.NumMethod() == 0 {
 			*(*interface{})(addr) = x
 		} else {

src/pkg/runtime/cgo/darwin_386.c

@@ -8,11 +8,13 @@
 static void* threadentry(void*);
 static pthread_key_t k1, k2;
 
+#define magic1 (0x23581321U)
+
 static void
 inittls(void)
 {
 	uint32 x, y;
-	pthread_key_t tofree[16], k;
+	pthread_key_t tofree[128], k;
 	int i, ntofree;
 	int havek1, havek2;
 
@@ -35,9 +37,8 @@ inittls(void)
 	 * 0x48+4*0x108 = 0x468 and 0x48+4*0x109 = 0x46c.
 	 *
 	 * The linker and runtime hard-code these constant offsets
-	 * from %gs where we expect to find m and g.  The code
-	 * below verifies that the constants are correct once it has
-	 * obtained the keys.  Known to ../cmd/8l/obj.c:/468
+	 * from %gs where we expect to find m and g.
+	 * Known to ../cmd/8l/obj.c:/468
 	 * and to ../pkg/runtime/darwin/386/sys.s:/468
 	 *
 	 * This is truly disgusting and a bit fragile, but taking care
@@ -48,55 +49,54 @@ inittls(void)
 	 * require an extra instruction and memory reference in
 	 * every stack growth prolog and would also require
 	 * rewriting the code that 8c generates for extern registers.
+	 *
+	 * Things get more disgusting on OS X 10.7 Lion.
+	 * The 0x48 base mentioned above is the offset of the tsd
+	 * array within the per-thread structure on Leopard and Snow Leopard.
+	 * On Lion, the base moved a little, so while the math above
+	 * still applies, the base is different.  Thus, we cannot
+	 * look for specific key values if we want to build binaries
+	 * that run on both systems.  Instead, forget about the
+	 * specific key values and just allocate and initialize per-thread
+	 * storage until we find a key that writes to the memory location
+	 * we want.  Then keep that key.
 	 */
 	havek1 = 0;
 	havek2 = 0;
 	ntofree = 0;
 	while(!havek1 || !havek2) {
 		if(pthread_key_create(&k, nil) < 0) {
-			fprintf(stderr, "libcgo: pthread_key_create failed\n");
+			fprintf(stderr, "runtime/cgo: pthread_key_create failed\n");
 			abort();
 		}
-		if(k == 0x108) {
+		pthread_setspecific(k, (void*)magic1);
+		asm volatile("movl %%gs:0x468, %0" : "=r"(x));
+		asm volatile("movl %%gs:0x46c, %0" : "=r"(y));
+		if(x == magic1) {
 			havek1 = 1;
 			k1 = k;
-			continue;
-		}
-		if(k == 0x109) {
+		} else if(y == magic1) {
 			havek2 = 1;
 			k2 = k;
-			continue;
+		} else {
+			if(ntofree >= nelem(tofree)) {
+				fprintf(stderr, "runtime/cgo: could not obtain pthread_keys\n");
+				fprintf(stderr, "\ttried");
+				for(i=0; i<ntofree; i++)
+					fprintf(stderr, " %#x", (unsigned)tofree[i]);
+				fprintf(stderr, "\n");
+				abort();
+			}
+			tofree[ntofree++] = k;
 		}
-		if(ntofree >= nelem(tofree)) {
-			fprintf(stderr, "libcgo: could not obtain pthread_keys\n");
-			fprintf(stderr, "\twanted 0x108 and 0x109\n");
-			fprintf(stderr, "\tgot");
-			for(i=0; i<ntofree; i++)
-				fprintf(stderr, " %#lx", tofree[i]);
-			fprintf(stderr, "\n");
-			abort();
-		}
-		tofree[ntofree++] = k;
+		pthread_setspecific(k, 0);
 	}
 
-	for(i=0; i<ntofree; i++)
-		pthread_key_delete(tofree[i]);
-
 	/*
-	 * We got the keys we wanted.  Make sure that we observe
-	 * updates to k1 at 0x468, to verify that the TLS array
-	 * offset from %gs hasn't changed.
+	 * We got the keys we wanted.  Free the others.
 	 */
-	pthread_setspecific(k1, (void*)0x12345678);
-	asm volatile("movl %%gs:0x468, %0" : "=r"(x));
-
-	pthread_setspecific(k1, (void*)0x87654321);
-	asm volatile("movl %%gs:0x468, %0" : "=r"(y));
-
-	if(x != 0x12345678 || y != 0x87654321) {
-		printf("libcgo: thread-local storage %#lx not at %%gs:0x468 - x=%#x y=%#x\n", k1, x, y);
-		abort();
-	}
+	for(i=0; i<ntofree; i++)
+		pthread_key_delete(tofree[i]);
 }
 
 static void

src/pkg/runtime/cgo/darwin_amd64.c

@@ -8,24 +8,25 @@
 static void* threadentry(void*);
 static pthread_key_t k1, k2;
 
+#define magic1 (0x23581321345589ULL)
+
 static void
 inittls(void)
 {
 	uint64 x, y;
-	pthread_key_t tofree[16], k;
+	pthread_key_t tofree[128], k;
 	int i, ntofree;
 	int havek1, havek2;
 
 	/*
 	 * Same logic, code as darwin_386.c:/inittls, except that words
-	 * are 8 bytes long now, and the thread-local storage starts at 0x60.
-	 * So the offsets are
+	 * are 8 bytes long now, and the thread-local storage starts
+	 * at 0x60 on Leopard / Snow Leopard. So the offsets are
 	 * 0x60+8*0x108 = 0x8a0 and 0x60+8*0x109 = 0x8a8.
 	 *
 	 * The linker and runtime hard-code these constant offsets
-	 * from %gs where we expect to find m and g.  The code
-	 * below verifies that the constants are correct once it has
-	 * obtained the keys.  Known to ../cmd/6l/obj.c:/8a0
+	 * from %gs where we expect to find m and g.
+	 * Known to ../cmd/6l/obj.c:/8a0
 	 * and to ../pkg/runtime/darwin/amd64/sys.s:/8a0
 	 *
 	 * As disgusting as on the 386; same justification.
@@ -35,49 +36,37 @@ inittls(void)
 	ntofree = 0;
 	while(!havek1 || !havek2) {
 		if(pthread_key_create(&k, nil) < 0) {
-			fprintf(stderr, "libcgo: pthread_key_create failed\n");
+			fprintf(stderr, "runtime/cgo: pthread_key_create failed\n");
 			abort();
 		}
-		if(k == 0x108) {
+		pthread_setspecific(k, (void*)magic1);
+		asm volatile("movq %%gs:0x8a0, %0" : "=r"(x));
+		asm volatile("movq %%gs:0x8a8, %0" : "=r"(y));
+		if(x == magic1) {
 			havek1 = 1;
 			k1 = k;
-			continue;
-		}
-		if(k == 0x109) {
+		} else if(y == magic1) {
 			havek2 = 1;
 			k2 = k;
-			continue;
+		} else {
+			if(ntofree >= nelem(tofree)) {
+				fprintf(stderr, "runtime/cgo: could not obtain pthread_keys\n");
+				fprintf(stderr, "\ttried");
+				for(i=0; i<ntofree; i++)
+					fprintf(stderr, " %#x", (unsigned)tofree[i]);
+				fprintf(stderr, "\n");
+				abort();
+			}
+			tofree[ntofree++] = k;
 		}
-		if(ntofree >= nelem(tofree)) {
-			fprintf(stderr, "libcgo: could not obtain pthread_keys\n");
-			fprintf(stderr, "\twanted 0x108 and 0x109\n");
-			fprintf(stderr, "\tgot");
-			for(i=0; i<ntofree; i++)
-				fprintf(stderr, " %#x", (unsigned)tofree[i]);
-			fprintf(stderr, "\n");
-			abort();
-		}
-		tofree[ntofree++] = k;
+		pthread_setspecific(k, 0);
 	}
 
-	for(i=0; i<ntofree; i++)
-		pthread_key_delete(tofree[i]);
-
 	/*
-	 * We got the keys we wanted.  Make sure that we observe
-	 * updates to k1 at 0x8a0, to verify that the TLS array
-	 * offset from %gs hasn't changed.
+	 * We got the keys we wanted.  Free the others.
 	 */
-	pthread_setspecific(k1, (void*)0x123456789abcdef0ULL);
-	asm volatile("movq %%gs:0x8a0, %0" : "=r"(x));
-
-	pthread_setspecific(k2, (void*)0x0fedcba987654321);
-	asm volatile("movq %%gs:0x8a8, %0" : "=r"(y));
-
-	if(x != 0x123456789abcdef0ULL || y != 0x0fedcba987654321) {
-		printf("libcgo: thread-local storage %#x not at %%gs:0x8a0 - x=%#llx y=%#llx\n", (unsigned)k1, x, y);
-		abort();
-	}
+	for(i=0; i<ntofree; i++)
+		pthread_key_delete(tofree[i]);
 }
 
 void

src/pkg/runtime/cgo/nacl_386.c

@@ -1,19 +0,0 @@
-// Copyright 2010 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.
-
-#include "libcgo.h"
-
-static void
-xinitcgo(void)
-{
-}
-
-void (*initcgo)(void) = xinitcgo;
-
-void
-libcgo_sys_thread_start(ThreadStart *ts)
-{
-	// unimplemented
-	*(int*)0 = 0;
-}

src/pkg/runtime/cgo/util.c

@@ -40,7 +40,7 @@ xlibcgo_thread_start(ThreadStart *arg)
 	/* Make our own copy that can persist after we return. */
 	ts = malloc(sizeof *ts);
 	if(ts == nil) {
-		fprintf(stderr, "libcgo: out of memory in thread_start\n");
+		fprintf(stderr, "runtime/cgo: out of memory in thread_start\n");
 		abort();
 	}
 	*ts = *arg;

test/fixedbugs/bug344.go

@@ -0,0 +1,22 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out || echo BUG: bug344
+
+// Copyright 2011 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
+
+import "fmt"
+
+func main() {
+	// invalid use of goto.
+	// do whatever you like, just don't crash.
+	i := 42
+	a := []*int{&i, &i, &i, &i}
+	x := a[0]
+	goto start
+	for _, x = range a {
+	start:
+		fmt.Sprint(*x)
+	}
+}

test/interface/fake.go

@@ -12,20 +12,20 @@ package main
 import "reflect"
 
 type T struct {
-	f float32
-	g float32
+	F float32
+	G float32
 
-	s string
-	t string
+	S string
+	T string
 
-	u uint32
-	v uint32
+	U uint32
+	V uint32
 
-	w uint32
-	x uint32
+	W uint32
+	X uint32
 
-	y uint32
-	z uint32
+	Y uint32
+	Z uint32
 }
 
 func add(s, t string) string {
@@ -40,16 +40,16 @@ func assert(b bool) {
 
 func main() {
 	var x T
-	x.f = 1.0
-	x.g = x.f
-	x.s = add("abc", "def")
-	x.t = add("abc", "def")
-	x.u = 1
-	x.v = 2
-	x.w = 1 << 28
-	x.x = 2 << 28
-	x.y = 0x12345678
-	x.z = x.y
+	x.F = 1.0
+	x.G = x.F
+	x.S = add("abc", "def")
+	x.T = add("abc", "def")
+	x.U = 1
+	x.V = 2
+	x.W = 1 << 28
+	x.X = 2 << 28
+	x.Y = 0x12345678
+	x.Z = x.Y
 
 	// check mem and string
 	v := reflect.ValueOf(x)