diff options
Diffstat (limited to 'src/cmd/compile/internal/base/debug.go')
| -rw-r--r-- | src/cmd/compile/internal/base/debug.go | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/base/debug.go b/src/cmd/compile/internal/base/debug.go new file mode 100644 index 0000000000..164941bb26 --- /dev/null +++ b/src/cmd/compile/internal/base/debug.go @@ -0,0 +1,194 @@ +// 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. + +// Debug arguments, set by -d flag. + +package base + +import ( + "fmt" + "log" + "os" + "reflect" + "strconv" + "strings" + + "cmd/internal/objabi" +) + +// Debug holds the parsed debugging configuration values. +var Debug = DebugFlags{ + Fieldtrack: &objabi.Fieldtrack_enabled, +} + +// DebugFlags defines the debugging configuration values (see var Debug). +// Each struct field is a different value, named for the lower-case of the field name. +// Each field must be an int or string and must have a `help` struct tag. +// +// The -d option takes a comma-separated list of settings. +// Each setting is name=value; for ints, name is short for name=1. +type DebugFlags struct { + Append int `help:"print information about append compilation"` + Checkptr int `help:"instrument unsafe pointer conversions"` + Closure int `help:"print information about closure compilation"` + DclStack int `help:"run internal dclstack check"` + Defer int `help:"print information about defer compilation"` + DisableNil int `help:"disable nil checks"` + DumpPtrs int `help:"show Node pointers values in dump output"` + DwarfInl int `help:"print information about DWARF inlined function creation"` + Export int `help:"print export data"` + Fieldtrack *int `help:"enable field tracking"` + GCProg int `help:"print dump of GC programs"` + Libfuzzer int `help:"enable coverage instrumentation for libfuzzer"` + LocationLists int `help:"print information about DWARF location list creation"` + Nil int `help:"print information about nil checks"` + PCTab string `help:"print named pc-value table"` + Panic int `help:"show all compiler panics"` + Slice int `help:"print information about slice compilation"` + SoftFloat int `help:"force compiler to emit soft-float code"` + TypeAssert int `help:"print information about type assertion inlining"` + TypecheckInl int `help:"eager typechecking of inline function bodies"` + WB int `help:"print information about write barriers"` + ABIWrap int `help:"print information about ABI wrapper generation"` + + any bool // set when any of the values have been set +} + +// Any reports whether any of the debug flags have been set. +func (d *DebugFlags) Any() bool { return d.any } + +type debugField struct { + name string + help string + val interface{} // *int or *string +} + +var debugTab []debugField + +func init() { + v := reflect.ValueOf(&Debug).Elem() + t := v.Type() + for i := 0; i < t.NumField(); i++ { + f := t.Field(i) + if f.Name == "any" { + continue + } + name := strings.ToLower(f.Name) + help := f.Tag.Get("help") + if help == "" { + panic(fmt.Sprintf("base.Debug.%s is missing help text", f.Name)) + } + ptr := v.Field(i).Addr().Interface() + switch ptr.(type) { + default: + panic(fmt.Sprintf("base.Debug.%s has invalid type %v (must be int or string)", f.Name, f.Type)) + case *int, *string: + // ok + case **int: + ptr = *ptr.(**int) // record the *int itself + } + debugTab = append(debugTab, debugField{name, help, ptr}) + } +} + +// DebugSSA is called to set a -d ssa/... option. +// If nil, those options are reported as invalid options. +// If DebugSSA returns a non-empty string, that text is reported as a compiler error. +var DebugSSA func(phase, flag string, val int, valString string) string + +// parseDebug parses the -d debug string argument. +func parseDebug(debugstr string) { + // parse -d argument + if debugstr == "" { + return + } + Debug.any = true +Split: + for _, name := range strings.Split(debugstr, ",") { + if name == "" { + continue + } + // display help about the -d option itself and quit + if name == "help" { + fmt.Print(debugHelpHeader) + maxLen := len("ssa/help") + for _, t := range debugTab { + if len(t.name) > maxLen { + maxLen = len(t.name) + } + } + for _, t := range debugTab { + fmt.Printf("\t%-*s\t%s\n", maxLen, t.name, t.help) + } + // ssa options have their own help + fmt.Printf("\t%-*s\t%s\n", maxLen, "ssa/help", "print help about SSA debugging") + fmt.Print(debugHelpFooter) + os.Exit(0) + } + val, valstring, haveInt := 1, "", true + if i := strings.IndexAny(name, "=:"); i >= 0 { + var err error + name, valstring = name[:i], name[i+1:] + val, err = strconv.Atoi(valstring) + if err != nil { + val, haveInt = 1, false + } + } + for _, t := range debugTab { + if t.name != name { + continue + } + switch vp := t.val.(type) { + case nil: + // Ignore + case *string: + *vp = valstring + case *int: + if !haveInt { + log.Fatalf("invalid debug value %v", name) + } + *vp = val + default: + panic("bad debugtab type") + } + continue Split + } + // special case for ssa for now + if DebugSSA != nil && strings.HasPrefix(name, "ssa/") { + // expect form ssa/phase/flag + // e.g. -d=ssa/generic_cse/time + // _ in phase name also matches space + phase := name[4:] + flag := "debug" // default flag is debug + if i := strings.Index(phase, "/"); i >= 0 { + flag = phase[i+1:] + phase = phase[:i] + } + err := DebugSSA(phase, flag, val, valstring) + if err != "" { + log.Fatalf(err) + } + continue Split + } + log.Fatalf("unknown debug key -d %s\n", name) + } +} + +const debugHelpHeader = `usage: -d arg[,arg]* and arg is <key>[=<value>] + +<key> is one of: + +` + +const debugHelpFooter = ` +<value> is key-specific. + +Key "checkptr" supports values: + "0": instrumentation disabled + "1": conversions involving unsafe.Pointer are instrumented + "2": conversions to unsafe.Pointer force heap allocation + +Key "pctab" supports values: + "pctospadj", "pctofile", "pctoline", "pctoinline", "pctopcdata" +` |