diff --git a/api/go1.8.txt b/api/go1.8.txt index e9ddc28079..d93de98e1a 100644 --- a/api/go1.8.txt +++ b/api/go1.8.txt @@ -155,7 +155,6 @@ pkg database/sql, type IsolationLevel int pkg database/sql, type NamedArg struct pkg database/sql, type NamedArg struct, Name string pkg database/sql, type NamedArg struct, Value interface{} -pkg debug/gosym, func PCValue([]uint8, uint64, int) int pkg debug/pe, method (*COFFSymbol) FullName(StringTable) (string, error) pkg debug/pe, method (StringTable) String(uint32) (string, error) pkg debug/pe, type File struct, COFFSymbols []COFFSymbol diff --git a/src/cmd/internal/objfile/goobj.go b/src/cmd/internal/objfile/goobj.go index 230137e0f5..c04987cc82 100644 --- a/src/cmd/internal/objfile/goobj.go +++ b/src/cmd/internal/objfile/goobj.go @@ -114,14 +114,14 @@ func (f *goobjFile) PCToLine(pc uint64) (string, int, *gosym.Func) { if err != nil { return "", 0, nil } - fileID := gosym.PCValue(pcfile, pc-uint64(s.Data.Offset), arch.MinLC) + fileID := int(pcValue(pcfile, pc-uint64(s.Data.Offset), arch)) fileName := s.Func.File[fileID] pcline := make([]byte, s.Func.PCLine.Size) _, err = f.f.ReadAt(pcline, s.Func.PCLine.Offset) if err != nil { return "", 0, nil } - line := gosym.PCValue(pcline, pc-uint64(s.Data.Offset), arch.MinLC) + line := int(pcValue(pcline, pc-uint64(s.Data.Offset), arch)) // Note: we provide only the name in the Func structure. // We could provide more if needed. return fileName, line, &gosym.Func{Sym: &gosym.Sym{Name: s.Name}} @@ -129,6 +129,53 @@ func (f *goobjFile) PCToLine(pc uint64) (string, int, *gosym.Func) { return "", 0, nil } +// pcValue looks up the given PC in a pc value table. target is the +// offset of the pc from the entry point. +func pcValue(tab []byte, target uint64, arch *sys.Arch) int32 { + val := int32(-1) + var pc uint64 + for step(&tab, &pc, &val, pc == 0, arch) { + if target < pc { + return val + } + } + return -1 +} + +// step advances to the next pc, value pair in the encoded table. +func step(p *[]byte, pc *uint64, val *int32, first bool, arch *sys.Arch) bool { + uvdelta := readvarint(p) + if uvdelta == 0 && !first { + return false + } + if uvdelta&1 != 0 { + uvdelta = ^(uvdelta >> 1) + } else { + uvdelta >>= 1 + } + vdelta := int32(uvdelta) + pcdelta := readvarint(p) * uint32(arch.MinLC) + *pc += uint64(pcdelta) + *val += vdelta + return true +} + +// readvarint reads, removes, and returns a varint from *p. +func readvarint(p *[]byte) uint32 { + var v, shift uint32 + s := *p + for shift = 0; ; shift += 7 { + b := s[0] + s = s[1:] + v |= (uint32(b) & 0x7F) << shift + if b&0x80 == 0 { + break + } + } + *p = s + return v +} + // We treat the whole object file as the text section. func (f *goobjFile) text() (textStart uint64, text []byte, err error) { var info os.FileInfo diff --git a/src/debug/gosym/pclntab.go b/src/debug/gosym/pclntab.go index e94ed19d7d..ba1cf8b699 100644 --- a/src/debug/gosym/pclntab.go +++ b/src/debug/gosym/pclntab.go @@ -291,13 +291,6 @@ func (t *LineTable) step(p *[]byte, pc *uint64, val *int32, first bool) bool { return true } -// PCValue looks up the given PC in a pc value table. target is the -// offset of the pc from the entry point. -func PCValue(tab []byte, target uint64, quantum int) int { - t := LineTable{Data: tab, quantum: uint32(quantum)} - return int(t.pcvalue(0, 0, target)) -} - // pcvalue reports the value associated with the target pc. // off is the offset to the beginning of the pc-value table, // and entry is the start PC for the corresponding function.