Merge branch 'golang:master' into master

Author: kevin-valerio

doc/next/6-stdlib/99-minor/os/73676.md

@@ -0,0 +1,4 @@
+On Windows, the [OpenFile] `flag` parameter can now contain any combination of
+Windows-specific file flags, such as `FILE_FLAG_OVERLAPPED` and
+`FILE_FLAG_SEQUENTIAL_SCAN`, for control of file or device caching behavior,
+access modes, and other special-purpose flags.

src/bytes/bytes.go

@@ -1117,41 +1117,34 @@ func trimRightUnicode(s []byte, cutset string) []byte {
 // TrimSpace returns a subslice of s by slicing off all leading and
 // trailing white space, as defined by Unicode.
 func TrimSpace(s []byte) []byte {
-	// Fast path for ASCII: look for the first ASCII non-space byte
-	start := 0
-	for ; start < len(s); start++ {
-		c := s[start]
+	// Fast path for ASCII: look for the first ASCII non-space byte.
+	for lo, c := range s {
 		if c >= utf8.RuneSelf {
 			// If we run into a non-ASCII byte, fall back to the
-			// slower unicode-aware method on the remaining bytes
-			return TrimFunc(s[start:], unicode.IsSpace)
-		}
-		if asciiSpace[c] == 0 {
-			break
+			// slower unicode-aware method on the remaining bytes.
+			return TrimFunc(s[lo:], unicode.IsSpace)
 		}
-	}
-
-	// Now look for the first ASCII non-space byte from the end
-	stop := len(s)
-	for ; stop > start; stop-- {
-		c := s[stop-1]
-		if c >= utf8.RuneSelf {
-			return TrimFunc(s[start:stop], unicode.IsSpace)
+		if asciiSpace[c] != 0 {
+			continue
 		}
-		if asciiSpace[c] == 0 {
-			break
+		s = s[lo:]
+		// Now look for the first ASCII non-space byte from the end.
+		for hi := len(s) - 1; hi >= 0; hi-- {
+			c := s[hi]
+			if c >= utf8.RuneSelf {
+				return TrimFunc(s[:hi+1], unicode.IsSpace)
+			}
+			if asciiSpace[c] == 0 {
+				// At this point, s[:hi+1] starts and ends with ASCII
+				// non-space bytes, so we're done. Non-ASCII cases have
+				// already been handled above.
+				return s[:hi+1]
+			}
 		}
 	}
-
-	// At this point s[start:stop] starts and ends with an ASCII
-	// non-space bytes, so we're done. Non-ASCII cases have already
-	// been handled above.
-	if start == stop {
-		// Special case to preserve previous TrimLeftFunc behavior,
-		// returning nil instead of empty slice if all spaces.
-		return nil
-	}
-	return s[start:stop]
+	// Special case to preserve previous TrimLeftFunc behavior,
+	// returning nil instead of empty slice if all spaces.
+	return nil
 }
 
 // Runes interprets s as a sequence of UTF-8-encoded code points.

src/cmd/cgo/gcc.go

@@ -27,6 +27,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"sync/atomic"
 	"unicode"
 	"unicode/utf8"
 
@@ -194,13 +195,12 @@ func (p *Package) Translate(f *File) {
 	var conv typeConv
 	conv.Init(p.PtrSize, p.IntSize)
 
-	p.typedefs = map[string]bool{}
-	p.typedefList = nil
+	ft := fileTypedefs{typedefs: make(map[string]bool)}
 	numTypedefs := -1
-	for len(p.typedefs) > numTypedefs {
-		numTypedefs = len(p.typedefs)
+	for len(ft.typedefs) > numTypedefs {
+		numTypedefs = len(ft.typedefs)
 		// Also ask about any typedefs we've seen so far.
-		for _, info := range p.typedefList {
+		for _, info := range ft.typedefList {
 			if f.Name[info.typedef] != nil {
 				continue
 			}
@@ -213,7 +213,8 @@ func (p *Package) Translate(f *File) {
 		}
 		needType := p.guessKinds(f)
 		if len(needType) > 0 {
-			p.loadDWARF(f, &conv, needType)
+			d := p.loadDWARF(f, &ft, needType)
+			p.recordTypes(f, d, &conv)
 		}
 
 		// In godefs mode we're OK with the typedefs, which
@@ -522,7 +523,7 @@ func (p *Package) guessKinds(f *File) []*Name {
 // loadDWARF parses the DWARF debug information generated
 // by gcc to learn the details of the constants, variables, and types
 // being referred to as C.xxx.
-func (p *Package) loadDWARF(f *File, conv *typeConv, names []*Name) {
+func (p *Package) loadDWARF(f *File, ft *fileTypedefs, names []*Name) *debug {
 	// Extract the types from the DWARF section of an object
 	// from a well-formed C program. Gcc only generates DWARF info
 	// for symbols in the object file, so it is not enough to print the
@@ -636,13 +637,28 @@ func (p *Package) loadDWARF(f *File, conv *typeConv, names []*Name) {
 				fatalf("malformed __cgo__ name: %s", name)
 			}
 			types[i] = t.Type
-			p.recordTypedefs(t.Type, f.NamePos[names[i]])
+			ft.recordTypedefs(t.Type, f.NamePos[names[i]])
 		}
 		if e.Tag != dwarf.TagCompileUnit {
 			r.SkipChildren()
 		}
 	}
 
+	return &debug{names, types, ints, floats, strs}
+}
+
+// debug is the data extracted by running an iteration of loadDWARF on a file.
+type debug struct {
+	names  []*Name
+	types  []dwarf.Type
+	ints   []int64
+	floats []float64
+	strs   []string
+}
+
+func (p *Package) recordTypes(f *File, data *debug, conv *typeConv) {
+	names, types, ints, floats, strs := data.names, data.types, data.ints, data.floats, data.strs
+
 	// Record types and typedef information.
 	for i, n := range names {
 		if strings.HasSuffix(n.Go, "GetTypeID") && types[i].String() == "func() CFTypeID" {
@@ -701,12 +717,17 @@ func (p *Package) loadDWARF(f *File, conv *typeConv, names []*Name) {
 	}
 }
 
-// recordTypedefs remembers in p.typedefs all the typedefs used in dtypes and its children.
-func (p *Package) recordTypedefs(dtype dwarf.Type, pos token.Pos) {
-	p.recordTypedefs1(dtype, pos, map[dwarf.Type]bool{})
+type fileTypedefs struct {
+	typedefs    map[string]bool // type names that appear in the types of the objects we're interested in
+	typedefList []typedefInfo
+}
+
+// recordTypedefs remembers in ft.typedefs all the typedefs used in dtypes and its children.
+func (ft *fileTypedefs) recordTypedefs(dtype dwarf.Type, pos token.Pos) {
+	ft.recordTypedefs1(dtype, pos, map[dwarf.Type]bool{})
 }
 
-func (p *Package) recordTypedefs1(dtype dwarf.Type, pos token.Pos, visited map[dwarf.Type]bool) {
+func (ft *fileTypedefs) recordTypedefs1(dtype dwarf.Type, pos token.Pos, visited map[dwarf.Type]bool) {
 	if dtype == nil {
 		return
 	}
@@ -720,25 +741,25 @@ func (p *Package) recordTypedefs1(dtype dwarf.Type, pos token.Pos, visited map[d
 			// Don't look inside builtin types. There be dragons.
 			return
 		}
-		if !p.typedefs[dt.Name] {
-			p.typedefs[dt.Name] = true
-			p.typedefList = append(p.typedefList, typedefInfo{dt.Name, pos})
-			p.recordTypedefs1(dt.Type, pos, visited)
+		if !ft.typedefs[dt.Name] {
+			ft.typedefs[dt.Name] = true
+			ft.typedefList = append(ft.typedefList, typedefInfo{dt.Name, pos})
+			ft.recordTypedefs1(dt.Type, pos, visited)
 		}
 	case *dwarf.PtrType:
-		p.recordTypedefs1(dt.Type, pos, visited)
+		ft.recordTypedefs1(dt.Type, pos, visited)
 	case *dwarf.ArrayType:
-		p.recordTypedefs1(dt.Type, pos, visited)
+		ft.recordTypedefs1(dt.Type, pos, visited)
 	case *dwarf.QualType:
-		p.recordTypedefs1(dt.Type, pos, visited)
+		ft.recordTypedefs1(dt.Type, pos, visited)
 	case *dwarf.FuncType:
-		p.recordTypedefs1(dt.ReturnType, pos, visited)
+		ft.recordTypedefs1(dt.ReturnType, pos, visited)
 		for _, a := range dt.ParamType {
-			p.recordTypedefs1(a, pos, visited)
+			ft.recordTypedefs1(a, pos, visited)
 		}
 	case *dwarf.StructType:
-		for _, f := range dt.Field {
-			p.recordTypedefs1(f.Type, pos, visited)
+		for _, l := range dt.Field {
+			ft.recordTypedefs1(l.Type, pos, visited)
 		}
 	}
 }
@@ -1756,20 +1777,23 @@ func gccMachine() []string {
 	return nil
 }
 
+var n atomic.Int64
+
 func gccTmp() string {
-	return *objDir + "_cgo_.o"
+	c := strconv.Itoa(int(n.Add(1)))
+	return *objDir + "_cgo_" + c + ".o"
 }
 
 // gccCmd returns the gcc command line to use for compiling
 // the input.
-func (p *Package) gccCmd() []string {
+func (p *Package) gccCmd(ofile string) []string {
 	c := append(gccBaseCmd,
-		"-w",          // no warnings
-		"-Wno-error",  // warnings are not errors
-		"-o"+gccTmp(), // write object to tmp
-		"-gdwarf-2",   // generate DWARF v2 debugging symbols
-		"-c",          // do not link
-		"-xc",         // input language is C
+		"-w",         // no warnings
+		"-Wno-error", // warnings are not errors
+		"-o"+ofile,   // write object to tmp
+		"-gdwarf-2",  // generate DWARF v2 debugging symbols
+		"-c",         // do not link
+		"-xc",        // input language is C
 	)
 	if p.GccIsClang {
 		c = append(c,
@@ -1806,7 +1830,8 @@ func (p *Package) gccCmd() []string {
 // gccDebug runs gcc -gdwarf-2 over the C program stdin and
 // returns the corresponding DWARF data and, if present, debug data block.
 func (p *Package) gccDebug(stdin []byte, nnames int) (d *dwarf.Data, ints []int64, floats []float64, strs []string) {
-	runGcc(stdin, p.gccCmd())
+	ofile := gccTmp()
+	runGcc(stdin, p.gccCmd(ofile))
 
 	isDebugInts := func(s string) bool {
 		// Some systems use leading _ to denote non-assembly symbols.
@@ -1856,11 +1881,11 @@ func (p *Package) gccDebug(stdin []byte, nnames int) (d *dwarf.Data, ints []int6
 		}
 	}
 
-	if f, err := macho.Open(gccTmp()); err == nil {
+	if f, err := macho.Open(ofile); err == nil {
 		defer f.Close()
 		d, err := f.DWARF()
 		if err != nil {
-			fatalf("cannot load DWARF output from %s: %v", gccTmp(), err)
+			fatalf("cannot load DWARF output from %s: %v", ofile, err)
 		}
 		bo := f.ByteOrder
 		if f.Symtab != nil {
@@ -1934,11 +1959,11 @@ func (p *Package) gccDebug(stdin []byte, nnames int) (d *dwarf.Data, ints []int6
 		return d, ints, floats, strs
 	}
 
-	if f, err := elf.Open(gccTmp()); err == nil {
+	if f, err := elf.Open(ofile); err == nil {
 		defer f.Close()
 		d, err := f.DWARF()
 		if err != nil {
-			fatalf("cannot load DWARF output from %s: %v", gccTmp(), err)
+			fatalf("cannot load DWARF output from %s: %v", ofile, err)
 		}
 		bo := f.ByteOrder
 		symtab, err := f.Symbols()
@@ -2034,11 +2059,11 @@ func (p *Package) gccDebug(stdin []byte, nnames int) (d *dwarf.Data, ints []int6
 		return d, ints, floats, strs
 	}
 
-	if f, err := pe.Open(gccTmp()); err == nil {
+	if f, err := pe.Open(ofile); err == nil {
 		defer f.Close()
 		d, err := f.DWARF()
 		if err != nil {
-			fatalf("cannot load DWARF output from %s: %v", gccTmp(), err)
+			fatalf("cannot load DWARF output from %s: %v", ofile, err)
 		}
 		bo := binary.LittleEndian
 		for _, s := range f.Symbols {
@@ -2106,11 +2131,11 @@ func (p *Package) gccDebug(stdin []byte, nnames int) (d *dwarf.Data, ints []int6
 		return d, ints, floats, strs
 	}
 
-	if f, err := xcoff.Open(gccTmp()); err == nil {
+	if f, err := xcoff.Open(ofile); err == nil {
 		defer f.Close()
 		d, err := f.DWARF()
 		if err != nil {
-			fatalf("cannot load DWARF output from %s: %v", gccTmp(), err)
+			fatalf("cannot load DWARF output from %s: %v", ofile, err)
 		}
 		bo := binary.BigEndian
 		for _, s := range f.Symbols {
@@ -2176,7 +2201,7 @@ func (p *Package) gccDebug(stdin []byte, nnames int) (d *dwarf.Data, ints []int6
 		buildStrings()
 		return d, ints, floats, strs
 	}
-	fatalf("cannot parse gcc output %s as ELF, Mach-O, PE, XCOFF object", gccTmp())
+	fatalf("cannot parse gcc output %s as ELF, Mach-O, PE, XCOFF object", ofile)
 	panic("not reached")
 }
 
@@ -2196,7 +2221,7 @@ func gccDefines(stdin []byte, gccOptions []string) string {
 // gcc to fail.
 func (p *Package) gccErrors(stdin []byte, extraArgs ...string) string {
 	// TODO(rsc): require failure
-	args := p.gccCmd()
+	args := p.gccCmd(gccTmp())
 
 	// Optimization options can confuse the error messages; remove them.
 	nargs := make([]string, 0, len(args)+len(extraArgs))

src/cmd/cgo/main.go

@@ -49,8 +49,6 @@ type Package struct {
 	GoFiles     []string        // list of Go files
 	GccFiles    []string        // list of gcc output files
 	Preamble    string          // collected preamble for _cgo_export.h
-	typedefs    map[string]bool // type names that appear in the types of the objects we're interested in
-	typedefList []typedefInfo
 	noCallbacks map[string]bool // C function names with #cgo nocallback directive
 	noEscapes   map[string]bool // C function names with #cgo noescape directive
 }

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

@@ -12,9 +12,7 @@
 (Mul64 ...) => (MUL  ...)
 (Mul64uhilo ...) => (LoweredMuluhilo ...)
 (Mul64uover ...) => (LoweredMuluover ...)
-(Mul32 ...) => (MULW ...)
-(Mul16 x y) => (MULW (SignExt16to32 x) (SignExt16to32 y))
-(Mul8 x y)  => (MULW (SignExt8to32 x)  (SignExt8to32 y))
+(Mul(32|16|8) ...) => (MULW ...)
 (Mul(64|32)F ...) => (FMUL(D|S) ...)
 
 (Div(64|32)F ...) => (FDIV(D|S) ...)

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

@@ -1896,22 +1896,10 @@
 (Neq(8|16|32|64) s:(Sub(8|16|32|64) x y) (Const(8|16|32|64) [0])) && s.Uses == 1 => (Neq(8|16|32|64) x y)
 
 // Optimize bitsets
-(Eq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [y])) && oneBit8(y)
-  => (Neq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [0]))
-(Eq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [y])) && oneBit16(y)
-  => (Neq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [0]))
-(Eq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [y])) && oneBit32(y)
-  => (Neq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [0]))
-(Eq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [y])) && oneBit64(y)
-  => (Neq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [0]))
-(Neq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [y])) && oneBit8(y)
-  => (Eq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [0]))
-(Neq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [y])) && oneBit16(y)
-  => (Eq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [0]))
-(Neq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [y])) && oneBit32(y)
-  => (Eq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [0]))
-(Neq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [y])) && oneBit64(y)
-  => (Eq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [0]))
+(Eq(8|16|32|64) (And(8|16|32|64) <t> x (Const(8|16|32|64) <t> [y])) (Const(8|16|32|64) <t> [y])) && oneBit(y)
+  => (Neq(8|16|32|64) (And(8|16|32|64) <t> x (Const(8|16|32|64) <t> [y])) (Const(8|16|32|64) <t> [0]))
+(Neq(8|16|32|64) (And(8|16|32|64) <t> x (Const(8|16|32|64) <t> [y])) (Const(8|16|32|64) <t> [y])) && oneBit(y)
+  => (Eq(8|16|32|64) (And(8|16|32|64) <t> x (Const(8|16|32|64) <t> [y])) (Const(8|16|32|64) <t> [0]))
 
 // Reassociate expressions involving
 // constants such that constants come first,

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

@@ -470,11 +470,10 @@ func ntz32(x int32) int { return bits.TrailingZeros32(uint32(x)) }
 func ntz16(x int16) int { return bits.TrailingZeros16(uint16(x)) }
 func ntz8(x int8) int   { return bits.TrailingZeros8(uint8(x)) }
 
-func oneBit(x int64) bool   { return x&(x-1) == 0 && x != 0 }
-func oneBit8(x int8) bool   { return x&(x-1) == 0 && x != 0 }
-func oneBit16(x int16) bool { return x&(x-1) == 0 && x != 0 }
-func oneBit32(x int32) bool { return x&(x-1) == 0 && x != 0 }
-func oneBit64(x int64) bool { return x&(x-1) == 0 && x != 0 }
+// oneBit reports whether x contains exactly one set bit.
+func oneBit[T int8 | int16 | int32 | int64](x T) bool {
+	return x&(x-1) == 0 && x != 0
+}
 
 // nto returns the number of trailing ones.
 func nto(x int64) int64 {