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Commit d728be70 authored by Dave Cheney's avatar Dave Cheney
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cmd/link/internal/ld: remove C style gotos from ldelf 

ld.ldelf contained a mixture of normal and C style, goto bad, error
handling. The use of goto requires many variables to be declared well
before their use which inhibited further refactoring to this method.

This CL removes the gotos in this function. Future CLs will address
remainder of the C style function scoped declarations in this function.

Change-Id: Ib9def495209a2f8deb11dcf30ee954bca95390c6
Reviewed-on: https://go-review.googlesource.com/41172
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarIan Lance Taylor <iant@golang.org>
parent 1db0aae3
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Inline Side-by-side
Showing with 47 additions and 38 deletions
src/cmd/link/internal/ld/ldelf.go
View file @ d728be70
......@@ -453,7 +453,6 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
var add uint64
var e binary.ByteOrder
var elfobj *ElfObj
var err error
var flag int
var hdr *ElfHdrBytes
var hdrbuf [64]uint8
......@@ -472,12 +471,14 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
var sym ElfSym
var symbols []*Symbol
if _, err := io.ReadFull(f, hdrbuf[:]); err != nil {
goto bad
Errorf(nil, "%s: malformed elf file: %v", pn, err)
return
}
hdr = new(ElfHdrBytes)
binary.Read(bytes.NewReader(hdrbuf[:]), binary.BigEndian, hdr) // only byte arrays; byte order doesn't matter
if string(hdr.Ident[:4]) != "\x7FELF" {
goto bad
Errorf(nil, "%s: malformed elf file", pn)
return
}
switch hdr.Ident[5] {
case ElfDataLsb:
......@@ -487,7 +488,8 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
e = binary.BigEndian
default:
goto bad
Errorf(nil, "%s: malformed elf file", pn)
return
}
// read header
......@@ -534,8 +536,9 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
elfobj.is64 = is64
if uint32(hdr.Ident[6]) != elfobj.version {
goto bad
if v := uint32(hdr.Ident[6]); v != elfobj.version {
Errorf(nil, "%s: malformed elf version: got %d, want %d", pn, v, elfobj.version)
return
}
if e.Uint16(hdr.Type[:]) != ElfTypeRelocatable {
......@@ -603,14 +606,16 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
elfobj.nsect = uint(elfobj.shnum)
for i := 0; uint(i) < elfobj.nsect; i++ {
if f.Seek(int64(uint64(base)+elfobj.shoff+uint64(int64(i)*int64(elfobj.shentsize))), 0) < 0 {
goto bad
Errorf(nil, "%s: malformed elf file", pn)
return
}
sect = &elfobj.sect[i]
if is64 != 0 {
var b ElfSectBytes64
if err = binary.Read(f, e, &b); err != nil {
goto bad
if err := binary.Read(f, e, &b); err != nil {
Errorf(nil, "%s: malformed elf file: %v", pn, err)
return
}
sect.nameoff = e.Uint32(b.Name[:])
......@@ -626,8 +631,9 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
} else {
var b ElfSectBytes
if err = binary.Read(f, e, &b); err != nil {
goto bad
if err := binary.Read(f, e, &b); err != nil {
Errorf(nil, "%s: malformed elf file: %v", pn, err)
return
}
sect.nameoff = e.Uint32(b.Name[:])
......@@ -645,13 +651,14 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
// read section string table and translate names
if elfobj.shstrndx >= uint32(elfobj.nsect) {
err = fmt.Errorf("shstrndx out of range %d >= %d", elfobj.shstrndx, elfobj.nsect)
goto bad
Errorf(nil, "%s: malformed elf file: shstrndx out of range %d >= %d", pn, elfobj.shstrndx, elfobj.nsect)
return
}
sect = &elfobj.sect[elfobj.shstrndx]
if err = elfmap(elfobj, sect); err != nil {
goto bad
if err := elfmap(elfobj, sect); err != nil {
Errorf(nil, "%s: malformed elf file: %v", pn, err)
return
}
for i := 0; uint(i) < elfobj.nsect; i++ {
if elfobj.sect[i].nameoff != 0 {
......@@ -679,11 +686,13 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
elfobj.nsymtab = int(elfobj.symtab.size / ELF32SYMSIZE)
}
if err = elfmap(elfobj, elfobj.symtab); err != nil {
goto bad
if err := elfmap(elfobj, elfobj.symtab); err != nil {
Errorf(nil, "%s: malformed elf file: %v", pn, err)
return
}
if err = elfmap(elfobj, elfobj.symstr); err != nil {
goto bad
if err := elfmap(elfobj, elfobj.symstr); err != nil {
Errorf(nil, "%s: malformed elf file: %v", pn, err)
return
}
// load text and data segments into memory.
......@@ -695,8 +704,9 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
for i := 0; uint(i) < elfobj.nsect; i++ {
sect = &elfobj.sect[i]
if sect.type_ == SHT_ARM_ATTRIBUTES && sect.name == ".ARM.attributes" {
if err = elfmap(elfobj, sect); err != nil {
goto bad
if err := elfmap(elfobj, sect); err != nil {
Errorf(nil, "%s: malformed elf file: %v", pn, err)
return
}
parseArmAttributes(ctxt, e, sect.base[:sect.size])
}
......@@ -704,8 +714,9 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
continue
}
if sect.type_ != ElfSectNobits {
if err = elfmap(elfobj, sect); err != nil {
goto bad
if err := elfmap(elfobj, sect); err != nil {
Errorf(nil, "%s: malformed elf file: %v", pn, err)
return
}
}
......@@ -714,8 +725,8 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
switch int(sect.flags) & (ElfSectFlagAlloc | ElfSectFlagWrite | ElfSectFlagExec) {
default:
err = fmt.Errorf("unexpected flags for ELF section %s", sect.name)
goto bad
Errorf(nil, "%s: unexpected flags for ELF section %s", pn, sect.name)
return
case ElfSectFlagAlloc:
s.Type = objabi.SRODATA
......@@ -749,8 +760,9 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
symbols = make([]*Symbol, elfobj.nsymtab)
for i := 1; i < elfobj.nsymtab; i++ {
if err = readelfsym(ctxt, elfobj, i, &sym, 1, localSymVersion); err != nil {
goto bad
if err := readelfsym(ctxt, elfobj, i, &sym, 1, localSymVersion); err != nil {
Errorf(nil, "%s: malformed elf file: %v", pn, err)
return
}
symbols[i] = sym.sym
if sym.type_ != ElfSymTypeFunc && sym.type_ != ElfSymTypeObject && sym.type_ != ElfSymTypeNone && sym.type_ != ElfSymTypeCommon {
......@@ -864,8 +876,9 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
continue
}
sect = &elfobj.sect[rsect.info]
if err = elfmap(elfobj, rsect); err != nil {
goto bad
if err := elfmap(elfobj, rsect); err != nil {
Errorf(nil, "%s: malformed elf file: %v", pn, err)
return
}
rela = 0
if rsect.type_ == ElfSectRela {
......@@ -911,13 +924,14 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
if info>>32 == 0 { // absolute relocation, don't bother reading the null symbol
rp.Sym = nil
} else {
if err = readelfsym(ctxt, elfobj, int(info>>32), &sym, 0, 0); err != nil {
goto bad
if err := readelfsym(ctxt, elfobj, int(info>>32), &sym, 0, 0); err != nil {
Errorf(nil, "%s: malformed elf file: %v", pn, err)
return
}
sym.sym = symbols[info>>32]
if sym.sym == nil {
err = fmt.Errorf("%s#%d: reloc of invalid sym #%d %s shndx=%d type=%d", sect.sym.Name, j, int(info>>32), sym.name, sym.shndx, sym.type_)
goto bad
Errorf(nil, "%s: malformed elf file: %s#%d: reloc of invalid sym #%d %s shndx=%d type=%d", pn, sect.sym.Name, j, int(info>>32), sym.name, sym.shndx, sym.type_)
return
}
rp.Sym = sym.sym
......@@ -954,11 +968,6 @@ func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
s.R = r
s.R = s.R[:n]
}
return
bad:
Errorf(nil, "%s: malformed elf file: %v", pn, err)
}
func section(elfobj *ElfObj, name string) *ElfSect {
......
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