runtime,runtime/pprof: clean up goroutine leak profile collection

api/next/73794.txt

@@ -0,0 +1 @@
+pkg bytes, method (*Buffer) Peek(int) ([]uint8, error) #73794

doc/next/6-stdlib/99-minor/bytes/73794.md

@@ -0,0 +1,2 @@
+The new [Buffer.Peek] method returns the next n bytes from the buffer without
+advancing it.

src/bytes/buffer.go

@@ -77,6 +77,18 @@ func (b *Buffer) String() string {
 	return string(b.buf[b.off:])
 }
 
+// Peek returns the next n bytes without advancing the buffer.
+// If Peek returns fewer than n bytes, it also returns [io.EOF].
+// The slice is only valid until the next call to a read or write method.
+// The slice aliases the buffer content at least until the next buffer modification,
+// so immediate changes to the slice will affect the result of future reads.
+func (b *Buffer) Peek(n int) ([]byte, error) {
+	if b.Len() < n {
+		return b.buf[b.off:], io.EOF
+	}
+	return b.buf[b.off:n], nil
+}
+
 // empty reports whether the unread portion of the buffer is empty.
 func (b *Buffer) empty() bool { return len(b.buf) <= b.off }
 

src/bytes/buffer_test.go

@@ -531,6 +531,34 @@ func TestReadString(t *testing.T) {
 	}
 }
 
+var peekTests = []struct {
+	buffer   string
+	n        int
+	expected string
+	err      error
+}{
+	{"", 0, "", nil},
+	{"aaa", 3, "aaa", nil},
+	{"foobar", 2, "fo", nil},
+	{"a", 2, "a", io.EOF},
+}
+
+func TestPeek(t *testing.T) {
+	for _, test := range peekTests {
+		buf := NewBufferString(test.buffer)
+		bytes, err := buf.Peek(test.n)
+		if string(bytes) != test.expected {
+			t.Errorf("expected %q, got %q", test.expected, bytes)
+		}
+		if err != test.err {
+			t.Errorf("expected error %v, got %v", test.err, err)
+		}
+		if buf.Len() != len(test.buffer) {
+			t.Errorf("bad length after peek: %d, want %d", buf.Len(), len(test.buffer))
+		}
+	}
+}
+
 func BenchmarkReadString(b *testing.B) {
 	const n = 32 << 10
 

src/bytes/bytes_test.go

@@ -1224,7 +1224,7 @@ func TestMap(t *testing.T) {
 	// Run a couple of awful growth/shrinkage tests
 	a := tenRunes('a')
 
-	// 1.  Grow. This triggers two reallocations in Map.
+	// 1. Grow. This triggers two reallocations in Map.
 	maxRune := func(r rune) rune { return unicode.MaxRune }
 	m := Map(maxRune, []byte(a))
 	expect := tenRunes(unicode.MaxRune)

src/cmd/asm/internal/asm/testdata/arm64.s

@@ -630,6 +630,8 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	FMOVS	F1, 0x44332211(R2)	// FMOVS	F1, 1144201745(R2)
 	FMOVD	F1, 0x1007000(R2)	// FMOVD	F1, 16805888(R2)
 	FMOVD	F1, 0x44332211(R2)	// FMOVD	F1, 1144201745(R2)
+	FMOVQ	F1, 0x1003000(R2)	// FMOVQ	F1, 16789504(R2)
+	FMOVQ	F1, 0x44332211(R2)	// FMOVQ	F1, 1144201745(R2)
 
 	MOVB	0x1000000(R1), R2	// MOVB		16777216(R1), R2
 	MOVB	0x44332211(R1), R2	// MOVB		1144201745(R1), R2
@@ -643,6 +645,8 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	FMOVS	0x44332211(R1), F2	// FMOVS	1144201745(R1), F2
 	FMOVD	0x1000000(R1), F2	// FMOVD	16777216(R1), F2
 	FMOVD	0x44332211(R1), F2	// FMOVD	1144201745(R1), F2
+	FMOVQ	0x1000000(R1), F2	// FMOVQ	16777216(R1), F2
+	FMOVQ	0x44332211(R1), F2	// FMOVQ	1144201745(R1), F2
 
 // shifted or extended register offset.
 	MOVD	(R2)(R6.SXTW), R4               // 44c866f8

src/cmd/asm/internal/asm/testdata/loong64enc1.s

@@ -533,12 +533,18 @@ lable2:
 	XVMOVQ		X28.V[3], X8    // 88ef0377
 	XVMOVQ		X27.V[0], X9    // 69e30377
 
-	//Move vector element to vector.
+	// Move vector element to vector.
 	VMOVQ		V1.B[3], V9.B16 // 298cf772
 	VMOVQ		V2.H[2], V8.H8  // 48c8f772
 	VMOVQ		V3.W[1], V7.W4  // 67e4f772
 	VMOVQ		V4.V[0], V6.V2  // 86f0f772
 
+	// Move vector register to vector register.
+	VMOVQ		V1, V9		// 29002d73
+	VMOVQ		V2, V8		// 48002d73
+	XVMOVQ		X3, X7		// 67002d77
+	XVMOVQ		X4, X6		// 86002d77
+
 	// Load data from memory and broadcast to each element of a vector register: VMOVQ    offset(Rj), <Vd>.<T>
 	VMOVQ		(R4), V0.B16	// 80008030
 	VMOVQ		1(R4), V0.B16	// 80048030
@@ -1017,6 +1023,12 @@ lable2:
 	XVSHUF4IV	$8, X1, X2	// 22209c77
 	XVSHUF4IV	$15, X1, X2	// 223c9c77
 
+	// VPERMIW, XVPERMI{W,V,Q} instructions
+	VPERMIW		$0x1B, V1, V2 	// VPERMIW	$27, V1, V2 // 226ce473
+	XVPERMIW	$0x2B, X1, X2 	// XVPERMIW	$43, X1, X2 // 22ace477
+	XVPERMIV	$0x3B, X1, X2 	// XVPERMIV	$59, X1, X2 // 22ece877
+	XVPERMIQ	$0x4B, X1, X2 	// XVPERMIQ	$75, X1, X2 // 222ced77
+
 	// [X]VSETEQZ.V, [X]VSETNEZ.V
 	VSETEQV		V1, FCC0	// 20989c72
 	VSETNEV		V1, FCC0	// 209c9c72

src/cmd/cgo/ast.go

@@ -363,7 +363,8 @@ func (f *File) walk(x interface{}, context astContext, visit func(*File, interfa
 
 	// everything else just recurs
 	default:
-		f.walkUnexpected(x, context, visit)
+		error_(token.NoPos, "unexpected type %T in walk", x)
+		panic("unexpected type")
 
 	case nil:
 
@@ -396,6 +397,9 @@ func (f *File) walk(x interface{}, context astContext, visit func(*File, interfa
 	case *ast.IndexExpr:
 		f.walk(&n.X, ctxExpr, visit)
 		f.walk(&n.Index, ctxExpr, visit)
+	case *ast.IndexListExpr:
+		f.walk(&n.X, ctxExpr, visit)
+		f.walk(n.Indices, ctxExpr, visit)
 	case *ast.SliceExpr:
 		f.walk(&n.X, ctxExpr, visit)
 		if n.Low != nil {
@@ -434,8 +438,8 @@ func (f *File) walk(x interface{}, context astContext, visit func(*File, interfa
 	case *ast.StructType:
 		f.walk(n.Fields, ctxField, visit)
 	case *ast.FuncType:
-		if tparams := funcTypeTypeParams(n); tparams != nil {
-			f.walk(tparams, ctxParam, visit)
+		if n.TypeParams != nil {
+			f.walk(n.TypeParams, ctxParam, visit)
 		}
 		f.walk(n.Params, ctxParam, visit)
 		if n.Results != nil {
@@ -524,8 +528,8 @@ func (f *File) walk(x interface{}, context astContext, visit func(*File, interfa
 			f.walk(n.Values, ctxExpr, visit)
 		}
 	case *ast.TypeSpec:
-		if tparams := typeSpecTypeParams(n); tparams != nil {
-			f.walk(tparams, ctxParam, visit)
+		if n.TypeParams != nil {
+			f.walk(n.TypeParams, ctxParam, visit)
 		}
 		f.walk(&n.Type, ctxType, visit)
 

src/cmd/cgo/doc.go

@@ -127,7 +127,7 @@ environment variable when running the go tool: set it to 1 to enable
 the use of cgo, and to 0 to disable it. The go tool will set the
 build constraint "cgo" if cgo is enabled. The special import "C"
 implies the "cgo" build constraint, as though the file also said
-"//go:build cgo".  Therefore, if cgo is disabled, files that import
+"//go:build cgo". Therefore, if cgo is disabled, files that import
 "C" will not be built by the go tool. (For more about build constraints
 see https://golang.org/pkg/go/build/#hdr-Build_Constraints).
 

src/cmd/cgo/gcc.go

@@ -1056,7 +1056,7 @@ func (p *Package) rewriteCall(f *File, call *Call) (string, bool) {
 func (p *Package) needsPointerCheck(f *File, t ast.Expr, arg ast.Expr) bool {
 	// An untyped nil does not need a pointer check, and when
 	// _cgoCheckPointer returns the untyped nil the type assertion we
-	// are going to insert will fail.  Easier to just skip nil arguments.
+	// are going to insert will fail. Easier to just skip nil arguments.
 	// TODO: Note that this fails if nil is shadowed.
 	if id, ok := arg.(*ast.Ident); ok && id.Name == "nil" {
 		return false
@@ -3010,7 +3010,7 @@ func (c *typeConv) FuncType(dtype *dwarf.FuncType, pos token.Pos) *FuncType {
 	for i, f := range dtype.ParamType {
 		// gcc's DWARF generator outputs a single DotDotDotType parameter for
 		// function pointers that specify no parameters (e.g. void
-		// (*__cgo_0)()).  Treat this special case as void. This case is
+		// (*__cgo_0)()). Treat this special case as void. This case is
 		// invalid according to ISO C anyway (i.e. void (*__cgo_1)(...) is not
 		// legal).
 		if _, ok := f.(*dwarf.DotDotDotType); ok && i == 0 {
@@ -3081,7 +3081,7 @@ func (c *typeConv) Struct(dt *dwarf.StructType, pos token.Pos) (expr *ast.Struct
 	off := int64(0)
 
 	// Rename struct fields that happen to be named Go keywords into
-	// _{keyword}.  Create a map from C ident -> Go ident. The Go ident will
+	// _{keyword}. Create a map from C ident -> Go ident. The Go ident will
 	// be mangled. Any existing identifier that already has the same name on
 	// the C-side will cause the Go-mangled version to be prefixed with _.
 	// (e.g. in a struct with fields '_type' and 'type', the latter would be
@@ -3309,7 +3309,7 @@ func godefsFields(fld []*ast.Field) {
 // fieldPrefix returns the prefix that should be removed from all the
 // field names when generating the C or Go code. For generated
 // C, we leave the names as is (tv_sec, tv_usec), since that's what
-// people are used to seeing in C.  For generated Go code, such as
+// people are used to seeing in C. For generated Go code, such as
 // package syscall's data structures, we drop a common prefix
 // (so sec, usec, which will get turned into Sec, Usec for exporting).
 func fieldPrefix(fld []*ast.Field) string {
@@ -3456,7 +3456,7 @@ func (c *typeConv) badCFType(dt *dwarf.TypedefType) bool {
 // Tagged pointer support
 // Low-bit set means tagged object, next 3 bits (currently)
 // define the tagged object class, next 4 bits are for type
-// information for the specific tagged object class.  Thus,
+// information for the specific tagged object class. Thus,
 // the low byte is for type info, and the rest of a pointer
 // (32 or 64-bit) is for payload, whatever the tagged class.
 //

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

@@ -4,9 +4,9 @@
 
 package cgotest
 
-// Test that we have no more than one build ID.  In the past we used
+// Test that we have no more than one build ID. In the past we used
 // to generate a separate build ID for each package using cgo, and the
-// linker concatenated them all.  We don't want that--we only want
+// linker concatenated them all. We don't want that--we only want
 // one.
 
 import (
@@ -42,7 +42,7 @@ sections:
 		for len(d) > 0 {
 
 			// ELF standards differ as to the sizes in
-			// note sections.  Both the GNU linker and
+			// note sections. Both the GNU linker and
 			// gold always generate 32-bit sizes, so that
 			// is what we assume here.
 

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

@@ -40,7 +40,7 @@ func nestedCall(f func()) {
 	callbackMutex.Unlock()
 
 	// Pass the address of i because the C function was written to
-	// take a pointer.  We could pass an int if we felt like
+	// take a pointer. We could pass an int if we felt like
 	// rewriting the C code.
 	C.callback(unsafe.Pointer(&i))
 

src/cmd/cgo/internal/test/gcc68255/a.go

@@ -3,7 +3,7 @@
 // license that can be found in the LICENSE file.
 
 // Test that it's OK to have C code that does nothing other than
-// initialize a global variable.  This used to fail with gccgo.
+// initialize a global variable. This used to fail with gccgo.
 
 package gcc68255
 

src/cmd/cgo/internal/teststdio/testdata/fib.go

@@ -5,7 +5,7 @@
 //go:build test_run
 
 // Compute Fibonacci numbers with two goroutines
-// that pass integers back and forth.  No actual
+// that pass integers back and forth. No actual
 // concurrency, just threads and synchronization
 // and foreign code on multiple pthreads.
 

src/cmd/cgo/main.go

@@ -72,8 +72,8 @@ type File struct {
 	ExpFunc     []*ExpFunc          // exported functions for this file
 	Name        map[string]*Name    // map from Go name to Name
 	NamePos     map[*Name]token.Pos // map from Name to position of the first reference
-	NoCallbacks map[string]bool     // C function names that with #cgo nocallback directive
-	NoEscapes   map[string]bool     // C function names that with #cgo noescape directive
+	NoCallbacks map[string]bool     // C function names with #cgo nocallback directive
+	NoEscapes   map[string]bool     // C function names with #cgo noescape directive
 	Edit        *edit.Buffer
 
 	debugs []*debug // debug data from iterations of gccDebug. Initialized by File.loadDebug.

src/cmd/cgo/out.go

@@ -1144,6 +1144,10 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) {
 					if !p.hasPointer(nil, atype, false) {
 						return
 					}
+
+					// Use the export'ed file/line in error messages.
+					pos := fset.Position(exp.Func.Pos())
+					fmt.Fprintf(fgo2, "//line %s:%d\n", pos.Filename, pos.Line)
 					fmt.Fprintf(fgo2, "\t_cgoCheckResult(a.r%d)\n", i)
 				})
 		}

src/cmd/compile/internal/ssa/_gen/RISCV64.rules

@@ -823,16 +823,16 @@
 (F(MADD|NMADD|MSUB|NMSUB)D x y neg:(FNEGD z)) && neg.Uses == 1 => (F(MSUB|NMSUB|MADD|NMADD)D x y z)
 
 // Test for -∞ (bit 0) using 64 bit classify instruction.
-(FLTD x (FMOVDconst [c])) && float64ExactBits(c, -math.MaxFloat64) => (ANDI [1] (FCLASSD x))
-(FLED (FMOVDconst [c]) x) && float64ExactBits(c, -math.MaxFloat64) => (SNEZ (ANDI <typ.Int64> [0xff &^ 1] (FCLASSD x)))
-(FEQD x (FMOVDconst [c])) && float64ExactBits(c, math.Inf(-1)) => (ANDI [1] (FCLASSD x))
-(FNED x (FMOVDconst [c])) && float64ExactBits(c, math.Inf(-1)) => (SEQZ (ANDI <typ.Int64> [1] (FCLASSD x)))
+(FLTD x (FMOVDconst [-math.MaxFloat64])) => (ANDI [0b00_0000_0001] (FCLASSD x))
+(FLED (FMOVDconst [-math.MaxFloat64]) x) => (SNEZ (ANDI <typ.Int64> [0b00_1111_1110] (FCLASSD x)))
+(FEQD x (FMOVDconst [math.Inf(-1)])) => (ANDI [0b00_0000_0001] (FCLASSD x))
+(FNED x (FMOVDconst [math.Inf(-1)])) => (SEQZ (ANDI <typ.Int64> [0b00_0000_0001] (FCLASSD x)))
 
 // Test for +∞ (bit 7) using 64 bit classify instruction.
-(FLTD (FMOVDconst [c]) x) && float64ExactBits(c, math.MaxFloat64) => (SNEZ (ANDI <typ.Int64> [1<<7] (FCLASSD x)))
-(FLED x (FMOVDconst [c])) && float64ExactBits(c, math.MaxFloat64) => (SNEZ (ANDI <typ.Int64> [0xff &^ (1<<7)] (FCLASSD x)))
-(FEQD x (FMOVDconst [c])) && float64ExactBits(c, math.Inf(1)) => (SNEZ (ANDI <typ.Int64> [1<<7] (FCLASSD x)))
-(FNED x (FMOVDconst [c])) && float64ExactBits(c, math.Inf(1)) => (SEQZ (ANDI <typ.Int64> [1<<7] (FCLASSD x)))
+(FLTD (FMOVDconst [math.MaxFloat64]) x) => (SNEZ (ANDI <typ.Int64> [0b00_1000_0000] (FCLASSD x)))
+(FLED x (FMOVDconst [math.MaxFloat64])) => (SNEZ (ANDI <typ.Int64> [0b00_0111_1111] (FCLASSD x)))
+(FEQD x (FMOVDconst [math.Inf(1)])) => (SNEZ (ANDI <typ.Int64> [0b00_1000_0000] (FCLASSD x)))
+(FNED x (FMOVDconst [math.Inf(1)])) => (SEQZ (ANDI <typ.Int64> [0b00_1000_0000] (FCLASSD x)))
 
 //
 // Optimisations for rva22u64 and above.