Adding upstream version 1.18.10.upstream/1.18.10upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 489 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/base/flag.go b/src/cmd/compile/internal/base/flag.go
new file mode 100644
index 0000000..d78f93b
--- /dev/null
+++ b/src/cmd/compile/internal/base/flag.go
@@ -0,0 +1,489 @@
+// 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 base
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"internal/buildcfg"
+	"io/ioutil"
+	"log"
+	"os"
+	"reflect"
+	"runtime"
+	"strings"
+
+	"cmd/internal/objabi"
+	"cmd/internal/sys"
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: compile [options] file.go...\n")
+	objabi.Flagprint(os.Stderr)
+	Exit(2)
+}
+
+// Flag holds the parsed command-line flags.
+// See ParseFlag for non-zero defaults.
+var Flag CmdFlags
+
+// A CountFlag is a counting integer flag.
+// It accepts -name=value to set the value directly,
+// but it also accepts -name with no =value to increment the count.
+type CountFlag int
+
+// CmdFlags defines the command-line flags (see var Flag).
+// Each struct field is a different flag, by default named for the lower-case of the field name.
+// If the flag name is a single letter, the default flag name is left upper-case.
+// If the flag name is "Lower" followed by a single letter, the default flag name is the lower-case of the last letter.
+//
+// If this default flag name can't be made right, the `flag` struct tag can be used to replace it,
+// but this should be done only in exceptional circumstances: it helps everyone if the flag name
+// is obvious from the field name when the flag is used elsewhere in the compiler sources.
+// The `flag:"-"` struct tag makes a field invisible to the flag logic and should also be used sparingly.
+//
+// Each field must have a `help` struct tag giving the flag help message.
+//
+// The allowed field types are bool, int, string, pointers to those (for values stored elsewhere),
+// CountFlag (for a counting flag), and func(string) (for a flag that uses special code for parsing).
+type CmdFlags struct {
+	// Single letters
+	B CountFlag    "help:\"disable bounds checking\""
+	C CountFlag    "help:\"disable printing of columns in error messages\""
+	D string       "help:\"set relative `path` for local imports\""
+	E CountFlag    "help:\"debug symbol export\""
+	G CountFlag    "help:\"accept generic code\""
+	I func(string) "help:\"add `directory` to import search path\""
+	K CountFlag    "help:\"debug missing line numbers\""
+	L CountFlag    "help:\"show full file names in error messages\""
+	N CountFlag    "help:\"disable optimizations\""
+	S CountFlag    "help:\"print assembly listing\""
+	// V is added by objabi.AddVersionFlag
+	W CountFlag "help:\"debug parse tree after type checking\""
+
+	LowerC int        "help:\"concurrency during compilation (1 means no concurrency)\""
+	LowerD flag.Value "help:\"enable debugging settings; try -d help\""
+	LowerE CountFlag  "help:\"no limit on number of errors reported\""
+	LowerH CountFlag  "help:\"halt on error\""
+	LowerJ CountFlag  "help:\"debug runtime-initialized variables\""
+	LowerL CountFlag  "help:\"disable inlining\""
+	LowerM CountFlag  "help:\"print optimization decisions\""
+	LowerO string     "help:\"write output to `file`\""
+	LowerP *string    "help:\"set expected package import `path`\"" // &Ctxt.Pkgpath, set below
+	LowerR CountFlag  "help:\"debug generated wrappers\""
+	LowerT bool       "help:\"enable tracing for debugging the compiler\""
+	LowerW CountFlag  "help:\"debug type checking\""
+	LowerV *bool      "help:\"increase debug verbosity\""
+
+	// Special characters
+	Percent          int  "flag:\"%\" help:\"debug non-static initializers\""
+	CompilingRuntime bool "flag:\"+\" help:\"compiling runtime\""
+
+	// Longer names
+	AsmHdr             string       "help:\"write assembly header to `file`\""
+	ASan               bool         "help:\"build code compatible with C/C++ address sanitizer\""
+	Bench              string       "help:\"append benchmark times to `file`\""
+	BlockProfile       string       "help:\"write block profile to `file`\""
+	BuildID            string       "help:\"record `id` as the build id in the export metadata\""
+	CPUProfile         string       "help:\"write cpu profile to `file`\""
+	Complete           bool         "help:\"compiling complete package (no C or assembly)\""
+	ClobberDead        bool         "help:\"clobber dead stack slots (for debugging)\""
+	ClobberDeadReg     bool         "help:\"clobber dead registers (for debugging)\""
+	Dwarf              bool         "help:\"generate DWARF symbols\""
+	DwarfBASEntries    *bool        "help:\"use base address selection entries in DWARF\""                        // &Ctxt.UseBASEntries, set below
+	DwarfLocationLists *bool        "help:\"add location lists to DWARF in optimized mode\""                      // &Ctxt.Flag_locationlists, set below
+	Dynlink            *bool        "help:\"support references to Go symbols defined in other shared libraries\"" // &Ctxt.Flag_dynlink, set below
+	EmbedCfg           func(string) "help:\"read go:embed configuration from `file`\""
+	GenDwarfInl        int          "help:\"generate DWARF inline info records\"" // 0=disabled, 1=funcs, 2=funcs+formals/locals
+	GoVersion          string       "help:\"required version of the runtime\""
+	ImportCfg          func(string) "help:\"read import configuration from `file`\""
+	ImportMap          func(string) "help:\"add `definition` of the form source=actual to import map\""
+	InstallSuffix      string       "help:\"set pkg directory `suffix`\""
+	JSON               string       "help:\"version,file for JSON compiler/optimizer detail output\""
+	Lang               string       "help:\"Go language version source code expects\""
+	LinkObj            string       "help:\"write linker-specific object to `file`\""
+	LinkShared         *bool        "help:\"generate code that will be linked against Go shared libraries\"" // &Ctxt.Flag_linkshared, set below
+	Live               CountFlag    "help:\"debug liveness analysis\""
+	MSan               bool         "help:\"build code compatible with C/C++ memory sanitizer\""
+	MemProfile         string       "help:\"write memory profile to `file`\""
+	MemProfileRate     int          "help:\"set runtime.MemProfileRate to `rate`\""
+	MutexProfile       string       "help:\"write mutex profile to `file`\""
+	NoLocalImports     bool         "help:\"reject local (relative) imports\""
+	Pack               bool         "help:\"write to file.a instead of file.o\""
+	Race               bool         "help:\"enable race detector\""
+	Shared             *bool        "help:\"generate code that can be linked into a shared library\"" // &Ctxt.Flag_shared, set below
+	SmallFrames        bool         "help:\"reduce the size limit for stack allocated objects\""      // small stacks, to diagnose GC latency; see golang.org/issue/27732
+	Spectre            string       "help:\"enable spectre mitigations in `list` (all, index, ret)\""
+	Std                bool         "help:\"compiling standard library\""
+	SymABIs            string       "help:\"read symbol ABIs from `file`\""
+	TraceProfile       string       "help:\"write an execution trace to `file`\""
+	TrimPath           string       "help:\"remove `prefix` from recorded source file paths\""
+	WB                 bool         "help:\"enable write barrier\"" // TODO: remove
+
+	// Configuration derived from flags; not a flag itself.
+	Cfg struct {
+		Embed struct { // set by -embedcfg
+			Patterns map[string][]string
+			Files    map[string]string
+		}
+		ImportDirs   []string          // appended to by -I
+		ImportMap    map[string]string // set by -importmap OR -importcfg
+		PackageFile  map[string]string // set by -importcfg; nil means not in use
+		SpectreIndex bool              // set by -spectre=index or -spectre=all
+		// Whether we are adding any sort of code instrumentation, such as
+		// when the race detector is enabled.
+		Instrumenting bool
+	}
+}
+
+// ParseFlags parses the command-line flags into Flag.
+func ParseFlags() {
+	Flag.G = 3
+	Flag.I = addImportDir
+
+	Flag.LowerC = 1
+	Flag.LowerD = objabi.NewDebugFlag(&Debug, DebugSSA)
+	Flag.LowerP = &Ctxt.Pkgpath
+	Flag.LowerV = &Ctxt.Debugvlog
+
+	Flag.Dwarf = buildcfg.GOARCH != "wasm"
+	Flag.DwarfBASEntries = &Ctxt.UseBASEntries
+	Flag.DwarfLocationLists = &Ctxt.Flag_locationlists
+	*Flag.DwarfLocationLists = true
+	Flag.Dynlink = &Ctxt.Flag_dynlink
+	Flag.EmbedCfg = readEmbedCfg
+	Flag.GenDwarfInl = 2
+	Flag.ImportCfg = readImportCfg
+	Flag.ImportMap = addImportMap
+	Flag.LinkShared = &Ctxt.Flag_linkshared
+	Flag.Shared = &Ctxt.Flag_shared
+	Flag.WB = true
+
+	Debug.InlFuncsWithClosures = 1
+	if buildcfg.Experiment.Unified {
+		Debug.Unified = 1
+	}
+
+	Debug.Checkptr = -1 // so we can tell whether it is set explicitly
+
+	Flag.Cfg.ImportMap = make(map[string]string)
+
+	objabi.AddVersionFlag() // -V
+	registerFlags()
+	objabi.Flagparse(usage)
+
+	if Flag.MSan && !sys.MSanSupported(buildcfg.GOOS, buildcfg.GOARCH) {
+		log.Fatalf("%s/%s does not support -msan", buildcfg.GOOS, buildcfg.GOARCH)
+	}
+	if Flag.ASan && !sys.ASanSupported(buildcfg.GOOS, buildcfg.GOARCH) {
+		log.Fatalf("%s/%s does not support -asan", buildcfg.GOOS, buildcfg.GOARCH)
+	}
+	if Flag.Race && !sys.RaceDetectorSupported(buildcfg.GOOS, buildcfg.GOARCH) {
+		log.Fatalf("%s/%s does not support -race", buildcfg.GOOS, buildcfg.GOARCH)
+	}
+	if (*Flag.Shared || *Flag.Dynlink || *Flag.LinkShared) && !Ctxt.Arch.InFamily(sys.AMD64, sys.ARM, sys.ARM64, sys.I386, sys.PPC64, sys.RISCV64, sys.S390X) {
+		log.Fatalf("%s/%s does not support -shared", buildcfg.GOOS, buildcfg.GOARCH)
+	}
+	parseSpectre(Flag.Spectre) // left as string for RecordFlags
+
+	Ctxt.Flag_shared = Ctxt.Flag_dynlink || Ctxt.Flag_shared
+	Ctxt.Flag_optimize = Flag.N == 0
+	Ctxt.Debugasm = int(Flag.S)
+	Ctxt.Flag_maymorestack = Debug.MayMoreStack
+
+	if flag.NArg() < 1 {
+		usage()
+	}
+
+	if Flag.GoVersion != "" && Flag.GoVersion != runtime.Version() {
+		fmt.Printf("compile: version %q does not match go tool version %q\n", runtime.Version(), Flag.GoVersion)
+		Exit(2)
+	}
+
+	if Flag.LowerO == "" {
+		p := flag.Arg(0)
+		if i := strings.LastIndex(p, "/"); i >= 0 {
+			p = p[i+1:]
+		}
+		if runtime.GOOS == "windows" {
+			if i := strings.LastIndex(p, `\`); i >= 0 {
+				p = p[i+1:]
+			}
+		}
+		if i := strings.LastIndex(p, "."); i >= 0 {
+			p = p[:i]
+		}
+		suffix := ".o"
+		if Flag.Pack {
+			suffix = ".a"
+		}
+		Flag.LowerO = p + suffix
+	}
+	switch {
+	case Flag.Race && Flag.MSan:
+		log.Fatal("cannot use both -race and -msan")
+	case Flag.Race && Flag.ASan:
+		log.Fatal("cannot use both -race and -asan")
+	case Flag.MSan && Flag.ASan:
+		log.Fatal("cannot use both -msan and -asan")
+	}
+	if Flag.Race || Flag.MSan || Flag.ASan {
+		// -race, -msan and -asan imply -d=checkptr for now.
+		if Debug.Checkptr == -1 { // if not set explicitly
+			Debug.Checkptr = 1
+		}
+	}
+
+	if Flag.CompilingRuntime && Flag.N != 0 {
+		log.Fatal("cannot disable optimizations while compiling runtime")
+	}
+	if Flag.LowerC < 1 {
+		log.Fatalf("-c must be at least 1, got %d", Flag.LowerC)
+	}
+	if Flag.LowerC > 1 && !concurrentBackendAllowed() {
+		log.Fatalf("cannot use concurrent backend compilation with provided flags; invoked as %v", os.Args)
+	}
+
+	if Flag.CompilingRuntime {
+		// Runtime can't use -d=checkptr, at least not yet.
+		Debug.Checkptr = 0
+
+		// Fuzzing the runtime isn't interesting either.
+		Debug.Libfuzzer = 0
+	}
+
+	if Debug.Checkptr == -1 { // if not set explicitly
+		Debug.Checkptr = 0
+	}
+
+	// set via a -d flag
+	Ctxt.Debugpcln = Debug.PCTab
+}
+
+// registerFlags adds flag registrations for all the fields in Flag.
+// See the comment on type CmdFlags for the rules.
+func registerFlags() {
+	var (
+		boolType      = reflect.TypeOf(bool(false))
+		intType       = reflect.TypeOf(int(0))
+		stringType    = reflect.TypeOf(string(""))
+		ptrBoolType   = reflect.TypeOf(new(bool))
+		ptrIntType    = reflect.TypeOf(new(int))
+		ptrStringType = reflect.TypeOf(new(string))
+		countType     = reflect.TypeOf(CountFlag(0))
+		funcType      = reflect.TypeOf((func(string))(nil))
+	)
+
+	v := reflect.ValueOf(&Flag).Elem()
+	t := v.Type()
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		if f.Name == "Cfg" {
+			continue
+		}
+
+		var name string
+		if len(f.Name) == 1 {
+			name = f.Name
+		} else if len(f.Name) == 6 && f.Name[:5] == "Lower" && 'A' <= f.Name[5] && f.Name[5] <= 'Z' {
+			name = string(rune(f.Name[5] + 'a' - 'A'))
+		} else {
+			name = strings.ToLower(f.Name)
+		}
+		if tag := f.Tag.Get("flag"); tag != "" {
+			name = tag
+		}
+
+		help := f.Tag.Get("help")
+		if help == "" {
+			panic(fmt.Sprintf("base.Flag.%s is missing help text", f.Name))
+		}
+
+		if k := f.Type.Kind(); (k == reflect.Ptr || k == reflect.Func) && v.Field(i).IsNil() {
+			panic(fmt.Sprintf("base.Flag.%s is uninitialized %v", f.Name, f.Type))
+		}
+
+		switch f.Type {
+		case boolType:
+			p := v.Field(i).Addr().Interface().(*bool)
+			flag.BoolVar(p, name, *p, help)
+		case intType:
+			p := v.Field(i).Addr().Interface().(*int)
+			flag.IntVar(p, name, *p, help)
+		case stringType:
+			p := v.Field(i).Addr().Interface().(*string)
+			flag.StringVar(p, name, *p, help)
+		case ptrBoolType:
+			p := v.Field(i).Interface().(*bool)
+			flag.BoolVar(p, name, *p, help)
+		case ptrIntType:
+			p := v.Field(i).Interface().(*int)
+			flag.IntVar(p, name, *p, help)
+		case ptrStringType:
+			p := v.Field(i).Interface().(*string)
+			flag.StringVar(p, name, *p, help)
+		case countType:
+			p := (*int)(v.Field(i).Addr().Interface().(*CountFlag))
+			objabi.Flagcount(name, help, p)
+		case funcType:
+			f := v.Field(i).Interface().(func(string))
+			objabi.Flagfn1(name, help, f)
+		default:
+			if val, ok := v.Field(i).Interface().(flag.Value); ok {
+				flag.Var(val, name, help)
+			} else {
+				panic(fmt.Sprintf("base.Flag.%s has unexpected type %s", f.Name, f.Type))
+			}
+		}
+	}
+}
+
+// concurrentFlagOk reports whether the current compiler flags
+// are compatible with concurrent compilation.
+func concurrentFlagOk() bool {
+	// TODO(rsc): Many of these are fine. Remove them.
+	return Flag.Percent == 0 &&
+		Flag.E == 0 &&
+		Flag.K == 0 &&
+		Flag.L == 0 &&
+		Flag.LowerH == 0 &&
+		Flag.LowerJ == 0 &&
+		Flag.LowerM == 0 &&
+		Flag.LowerR == 0
+}
+
+func concurrentBackendAllowed() bool {
+	if !concurrentFlagOk() {
+		return false
+	}
+
+	// Debug.S by itself is ok, because all printing occurs
+	// while writing the object file, and that is non-concurrent.
+	// Adding Debug_vlog, however, causes Debug.S to also print
+	// while flushing the plist, which happens concurrently.
+	if Ctxt.Debugvlog || Debug.Any || Flag.Live > 0 {
+		return false
+	}
+	// TODO: Test and delete this condition.
+	if buildcfg.Experiment.FieldTrack {
+		return false
+	}
+	// TODO: fix races and enable the following flags
+	if Ctxt.Flag_dynlink || Flag.Race {
+		return false
+	}
+	return true
+}
+
+func addImportDir(dir string) {
+	if dir != "" {
+		Flag.Cfg.ImportDirs = append(Flag.Cfg.ImportDirs, dir)
+	}
+}
+
+func addImportMap(s string) {
+	if Flag.Cfg.ImportMap == nil {
+		Flag.Cfg.ImportMap = make(map[string]string)
+	}
+	if strings.Count(s, "=") != 1 {
+		log.Fatal("-importmap argument must be of the form source=actual")
+	}
+	i := strings.Index(s, "=")
+	source, actual := s[:i], s[i+1:]
+	if source == "" || actual == "" {
+		log.Fatal("-importmap argument must be of the form source=actual; source and actual must be non-empty")
+	}
+	Flag.Cfg.ImportMap[source] = actual
+}
+
+func readImportCfg(file string) {
+	if Flag.Cfg.ImportMap == nil {
+		Flag.Cfg.ImportMap = make(map[string]string)
+	}
+	Flag.Cfg.PackageFile = map[string]string{}
+	data, err := ioutil.ReadFile(file)
+	if err != nil {
+		log.Fatalf("-importcfg: %v", err)
+	}
+
+	for lineNum, line := range strings.Split(string(data), "\n") {
+		lineNum++ // 1-based
+		line = strings.TrimSpace(line)
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+
+		var verb, args string
+		if i := strings.Index(line, " "); i < 0 {
+			verb = line
+		} else {
+			verb, args = line[:i], strings.TrimSpace(line[i+1:])
+		}
+		var before, after string
+		if i := strings.Index(args, "="); i >= 0 {
+			before, after = args[:i], args[i+1:]
+		}
+		switch verb {
+		default:
+			log.Fatalf("%s:%d: unknown directive %q", file, lineNum, verb)
+		case "importmap":
+			if before == "" || after == "" {
+				log.Fatalf(`%s:%d: invalid importmap: syntax is "importmap old=new"`, file, lineNum)
+			}
+			Flag.Cfg.ImportMap[before] = after
+		case "packagefile":
+			if before == "" || after == "" {
+				log.Fatalf(`%s:%d: invalid packagefile: syntax is "packagefile path=filename"`, file, lineNum)
+			}
+			Flag.Cfg.PackageFile[before] = after
+		}
+	}
+}
+
+func readEmbedCfg(file string) {
+	data, err := ioutil.ReadFile(file)
+	if err != nil {
+		log.Fatalf("-embedcfg: %v", err)
+	}
+	if err := json.Unmarshal(data, &Flag.Cfg.Embed); err != nil {
+		log.Fatalf("%s: %v", file, err)
+	}
+	if Flag.Cfg.Embed.Patterns == nil {
+		log.Fatalf("%s: invalid embedcfg: missing Patterns", file)
+	}
+	if Flag.Cfg.Embed.Files == nil {
+		log.Fatalf("%s: invalid embedcfg: missing Files", file)
+	}
+}
+
+// parseSpectre parses the spectre configuration from the string s.
+func parseSpectre(s string) {
+	for _, f := range strings.Split(s, ",") {
+		f = strings.TrimSpace(f)
+		switch f {
+		default:
+			log.Fatalf("unknown setting -spectre=%s", f)
+		case "":
+			// nothing
+		case "all":
+			Flag.Cfg.SpectreIndex = true
+			Ctxt.Retpoline = true
+		case "index":
+			Flag.Cfg.SpectreIndex = true
+		case "ret":
+			Ctxt.Retpoline = true
+		}
+	}
+
+	if Flag.Cfg.SpectreIndex {
+		switch buildcfg.GOARCH {
+		case "amd64":
+			// ok
+		default:
+			log.Fatalf("GOARCH=%s does not support -spectre=index", buildcfg.GOARCH)
+		}
+	}
+}