diff --git a/src/cmd/link/internal/amd64/asm.go b/src/cmd/link/internal/amd64/asm.go
index d26a9a234cc3fd081b45c93376b0baa1c47d3ab3..5c4ffe19c256591adeb43b820a4a6eaadf999df3 100644
--- a/src/cmd/link/internal/amd64/asm.go
+++ b/src/cmd/link/internal/amd64/asm.go
@@ -756,6 +756,7 @@ func asmb2(ctxt *ld.Link) {
if ctxt.IsELF {
ctxt.Out.SeekSet(symo)
ld.Asmelfsym(ctxt)
+ ctxt.Out.Flush()
ctxt.Out.Write(ld.Elfstrdat)
if ctxt.LinkMode == ld.LinkExternal {
@@ -765,11 +766,13 @@ func asmb2(ctxt *ld.Link) {
case objabi.Hplan9:
ld.Asmplan9sym(ctxt)
+ ctxt.Out.Flush()
sym := ctxt.Syms.Lookup("pclntab", 0)
if sym != nil {
ld.Lcsize = int32(len(sym.P))
ctxt.Out.Write(sym.P)
+ ctxt.Out.Flush()
}
case objabi.Hwindows:
@@ -814,6 +817,8 @@ func asmb2(ctxt *ld.Link) {
case objabi.Hwindows:
ld.Asmbpe(ctxt)
}
+
+ ctxt.Out.Flush()
}
func tlsIEtoLE(s *sym.Symbol, off, size int) {
diff --git a/src/cmd/link/internal/arm/asm.go b/src/cmd/link/internal/arm/asm.go
index e9eea5ce2c9ec1c8819092e1e2b30a62c4f68b41..f3d1262879a6edc876190254e7de6934a231b9f9 100644
--- a/src/cmd/link/internal/arm/asm.go
+++ b/src/cmd/link/internal/arm/asm.go
@@ -816,6 +816,7 @@ func asmb2(ctxt *ld.Link) {
default:
if ctxt.IsELF {
ld.Asmelfsym(ctxt)
+ ctxt.Out.Flush()
ctxt.Out.Write(ld.Elfstrdat)
if ctxt.LinkMode == ld.LinkExternal {
@@ -825,11 +826,13 @@ func asmb2(ctxt *ld.Link) {
case objabi.Hplan9:
ld.Asmplan9sym(ctxt)
+ ctxt.Out.Flush()
sym := ctxt.Syms.Lookup("pclntab", 0)
if sym != nil {
ld.Lcsize = int32(len(sym.P))
ctxt.Out.Write(sym.P)
+ ctxt.Out.Flush()
}
case objabi.Hwindows:
@@ -860,6 +863,7 @@ func asmb2(ctxt *ld.Link) {
ld.Asmbpe(ctxt)
}
+ ctxt.Out.Flush()
if *ld.FlagC {
fmt.Printf("textsize=%d\n", ld.Segtext.Filelen)
fmt.Printf("datsize=%d\n", ld.Segdata.Filelen)
diff --git a/src/cmd/link/internal/arm64/asm.go b/src/cmd/link/internal/arm64/asm.go
index 46bda74c4c5118b3d4c8c36c6e07871a6015257c..053b8d119d99b6ace1692a688b7a2a27374530fa 100644
--- a/src/cmd/link/internal/arm64/asm.go
+++ b/src/cmd/link/internal/arm64/asm.go
@@ -866,6 +866,7 @@ func asmb2(ctxt *ld.Link) {
default:
if ctxt.IsELF {
ld.Asmelfsym(ctxt)
+ ctxt.Out.Flush()
ctxt.Out.Write(ld.Elfstrdat)
if ctxt.LinkMode == ld.LinkExternal {
@@ -875,11 +876,13 @@ func asmb2(ctxt *ld.Link) {
case objabi.Hplan9:
ld.Asmplan9sym(ctxt)
+ ctxt.Out.Flush()
sym := ctxt.Syms.Lookup("pclntab", 0)
if sym != nil {
ld.Lcsize = int32(len(sym.P))
ctxt.Out.Write(sym.P)
+ ctxt.Out.Flush()
}
case objabi.Hdarwin:
@@ -912,6 +915,7 @@ func asmb2(ctxt *ld.Link) {
ld.Asmbmacho(ctxt)
}
+ ctxt.Out.Flush()
if *ld.FlagC {
fmt.Printf("textsize=%d\n", ld.Segtext.Filelen)
fmt.Printf("datsize=%d\n", ld.Segdata.Filelen)
diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go
index 36708ee5d1ebb16689f2185d8af085b38e042d6b..3979880cf4d7a7ad3e6ad69e75f3df3edc3e455c 100644
--- a/src/cmd/link/internal/ld/data.go
+++ b/src/cmd/link/internal/ld/data.go
@@ -32,6 +32,7 @@
package ld
import (
+ "bufio"
"bytes"
"cmd/internal/gcprog"
"cmd/internal/objabi"
@@ -957,10 +958,11 @@ func Datblk(ctxt *Link, out *OutBuf, addr, size int64) {
// Used only on Wasm for now.
func DatblkBytes(ctxt *Link, addr int64, size int64) []byte {
- buf := make([]byte, size)
- out := &OutBuf{heap: buf}
+ buf := bytes.NewBuffer(make([]byte, 0, size))
+ out := &OutBuf{w: bufio.NewWriter(buf)}
writeDatblkToOutBuf(ctxt, out, addr, size)
- return buf
+ out.Flush()
+ return buf.Bytes()
}
func writeDatblkToOutBuf(ctxt *Link, out *OutBuf, addr int64, size int64) {
diff --git a/src/cmd/link/internal/ld/main.go b/src/cmd/link/internal/ld/main.go
index ff9d1b51a3cf08d21893801eb48dbbf396238c17..dd089e6efa5ae19344f23b409f374d694923968b 100644
--- a/src/cmd/link/internal/ld/main.go
+++ b/src/cmd/link/internal/ld/main.go
@@ -319,25 +319,35 @@ func Main(arch *sys.Arch, theArch Arch) {
// for which we have computed the size and offset, in a
// mmap'd region. The second part writes more content, for
// which we don't know the size.
+ var outputMmapped bool
if ctxt.Arch.Family != sys.Wasm {
// Don't mmap if we're building for Wasm. Wasm file
// layout is very different so filesize is meaningless.
- if err := ctxt.Out.Mmap(filesize); err != nil {
- ctxt.Errorf(0, "error mapping file: %v", err)
- }
+ err := ctxt.Out.Mmap(filesize)
+ outputMmapped = err == nil
+ }
+ if outputMmapped {
+ // Asmb will redirect symbols to the output file mmap, and relocations
+ // will be applied directly there.
+ bench.Start("Asmb")
+ thearch.Asmb(ctxt)
+ bench.Start("reloc")
+ ctxt.reloc()
+ } else {
+ // If we don't mmap, we need to apply relocations before
+ // writing out.
+ bench.Start("reloc")
+ ctxt.reloc()
+ bench.Start("Asmb")
+ thearch.Asmb(ctxt)
}
-
- // Asmb will redirect symbols to the output file mmap, and relocations
- // will be applied directly there.
- bench.Start("Asmb")
- thearch.Asmb(ctxt)
- bench.Start("reloc")
- ctxt.reloc()
bench.Start("Asmb2")
thearch.Asmb2(ctxt)
- bench.Start("Munmap")
- ctxt.Out.Close() // Close handles Munmapping if necessary.
+ if outputMmapped {
+ bench.Start("Munmap")
+ ctxt.Out.Munmap()
+ }
bench.Start("undef")
ctxt.undef()
diff --git a/src/cmd/link/internal/ld/outbuf.go b/src/cmd/link/internal/ld/outbuf.go
index 490d9b5b7a96c54705a1323129303b5ecf644a7f..c36fc74a445dab6d811a8dbb889a5c8add57c5e3 100644
--- a/src/cmd/link/internal/ld/outbuf.go
+++ b/src/cmd/link/internal/ld/outbuf.go
@@ -5,6 +5,7 @@
package ld
import (
+ "bufio"
"cmd/internal/sys"
"cmd/link/internal/sym"
"encoding/binary"
@@ -60,6 +61,7 @@ type OutBuf struct {
buf []byte // backing store of mmap'd output file
heap []byte // backing store for non-mmapped data
+ w *bufio.Writer
name string
f *os.File
encbuf [8]byte // temp buffer used by WriteN methods
@@ -76,6 +78,7 @@ func (out *OutBuf) Open(name string) error {
}
out.off = 0
out.name = name
+ out.w = bufio.NewWriter(f)
out.f = f
return nil
}
@@ -107,17 +110,10 @@ func (out *OutBuf) Close() error {
if out.isView {
return viewCloseError
}
- if out.isMmapped() {
- return out.Munmap()
- }
+ out.Flush()
if out.f == nil {
return nil
}
- if len(out.heap) != 0 {
- if _, err := out.f.Write(out.heap); err != nil {
- return err
- }
- }
if err := out.f.Close(); err != nil {
return err
}
@@ -155,6 +151,10 @@ func (out *OutBuf) Munmap() error {
// writing. When the mmapped section is full, we switch over the heap memory
// for writing.
func (out *OutBuf) writeLoc(lenToWrite int64) (int64, []byte) {
+ if !out.isMmapped() {
+ panic("shouldn't happen")
+ }
+
// See if we have enough space in the mmaped area.
bufLen := int64(len(out.buf))
if out.off+lenToWrite <= bufLen {
@@ -178,6 +178,15 @@ func (out *OutBuf) writeLoc(lenToWrite int64) (int64, []byte) {
}
func (out *OutBuf) SeekSet(p int64) {
+ if p == out.off {
+ return
+ }
+ if !out.isMmapped() {
+ out.Flush()
+ if _, err := out.f.Seek(p, 0); err != nil {
+ Exitf("seeking to %d in %s: %v", p, out.name, err)
+ }
+ }
out.off = p
}
@@ -186,18 +195,33 @@ func (out *OutBuf) Offset() int64 {
}
// Write writes the contents of v to the buffer.
+//
+// As Write is backed by a bufio.Writer, callers do not have
+// to explicitly handle the returned error as long as Flush is
+// eventually called.
func (out *OutBuf) Write(v []byte) (int, error) {
- n := len(v)
- pos, buf := out.writeLoc(int64(n))
- copy(buf[pos:], v)
+ if out.isMmapped() {
+ n := len(v)
+ pos, buf := out.writeLoc(int64(n))
+ copy(buf[pos:], v)
+ out.off += int64(n)
+ return n, nil
+ }
+ n, err := out.w.Write(v)
out.off += int64(n)
- return n, nil
+ return n, err
}
func (out *OutBuf) Write8(v uint8) {
- pos, buf := out.writeLoc(1)
- buf[pos] = v
- out.off++
+ if out.isMmapped() {
+ pos, buf := out.writeLoc(1)
+ buf[pos] = v
+ out.off++
+ return
+ }
+ if err := out.w.WriteByte(v); err == nil {
+ out.off++
+ }
}
// WriteByte is an alias for Write8 to fulfill the io.ByteWriter interface.
@@ -232,11 +256,16 @@ func (out *OutBuf) Write64b(v uint64) {
}
func (out *OutBuf) WriteString(s string) {
- pos, buf := out.writeLoc(int64(len(s)))
- n := copy(buf[pos:], s)
- if n != len(s) {
- log.Fatalf("WriteString truncated. buffer size: %d, offset: %d, len(s)=%d", len(out.buf), out.off, len(s))
+ if out.isMmapped() {
+ pos, buf := out.writeLoc(int64(len(s)))
+ n := copy(buf[pos:], s)
+ if n != len(s) {
+ log.Fatalf("WriteString truncated. buffer size: %d, offset: %d, len(s)=%d", len(out.buf), out.off, len(s))
+ }
+ out.off += int64(n)
+ return
}
+ n, _ := out.w.WriteString(s)
out.off += int64(n)
}
@@ -268,10 +297,26 @@ func (out *OutBuf) WriteStringPad(s string, n int, pad []byte) {
// edit to the symbol content.
// If the output file is not Mmap'd, just writes the content.
func (out *OutBuf) WriteSym(s *sym.Symbol) {
- n := int64(len(s.P))
- pos, buf := out.writeLoc(n)
- copy(buf[pos:], s.P)
- out.off += n
- s.P = buf[pos : pos+n]
- s.Attr.Set(sym.AttrReadOnly, false)
+ // NB: We inline the Write call for speediness.
+ if out.isMmapped() {
+ n := int64(len(s.P))
+ pos, buf := out.writeLoc(n)
+ copy(buf[pos:], s.P)
+ out.off += n
+ s.P = buf[pos : pos+n]
+ s.Attr.Set(sym.AttrReadOnly, false)
+ } else {
+ n, _ := out.w.Write(s.P)
+ out.off += int64(n)
+ }
+}
+
+func (out *OutBuf) Flush() {
+ var err error
+ if out.w != nil {
+ err = out.w.Flush()
+ }
+ if err != nil {
+ Exitf("flushing %s: %v", out.name, err)
+ }
}
diff --git a/src/cmd/link/internal/ld/outbuf_test.go b/src/cmd/link/internal/ld/outbuf_test.go
index 58f9b10cfa46485ba6305c12f9d30ad44fe7ba71..aae206f511a824d7bde953a7caf98c7e14d830bf 100644
--- a/src/cmd/link/internal/ld/outbuf_test.go
+++ b/src/cmd/link/internal/ld/outbuf_test.go
@@ -50,7 +50,6 @@ func TestWriteLoc(t *testing.T) {
{100, 100, 0, 100, 100, 0, true},
{10, 10, 0, 100, 100, 0, true},
{10, 20, 10, 100, 110, 10, true},
- {0, 0, 0, 100, 100, 0, true},
}
for i, test := range tests {
diff --git a/src/cmd/link/internal/ld/xcoff.go b/src/cmd/link/internal/ld/xcoff.go
index 9fe3669eee2f32d997b3ddfd251011bc8818c9bc..4ff123e8cd6c591bb0afc825676e5374fc8e044d 100644
--- a/src/cmd/link/internal/ld/xcoff.go
+++ b/src/cmd/link/internal/ld/xcoff.go
@@ -1389,6 +1389,7 @@ func (f *xcoffFile) writeLdrScn(ctxt *Link, globalOff uint64) {
}
f.loaderSize = off + uint64(stlen)
+ ctxt.Out.Flush()
/* again for printing */
if !*flagA {
@@ -1558,6 +1559,8 @@ func Asmbxcoff(ctxt *Link, fileoff int64) {
// write string table
xfile.stringTable.write(ctxt.Out)
+ ctxt.Out.Flush()
+
// write headers
xcoffwrite(ctxt)
}
diff --git a/src/cmd/link/internal/mips/asm.go b/src/cmd/link/internal/mips/asm.go
index 21a57ccbb0d182345685c87985c74272813bc123..b50112ad750ffa83567d421af2ba2df86c054077 100644
--- a/src/cmd/link/internal/mips/asm.go
+++ b/src/cmd/link/internal/mips/asm.go
@@ -204,6 +204,7 @@ func asmb2(ctxt *ld.Link) {
ctxt.Out.SeekSet(int64(symo))
ld.Asmelfsym(ctxt)
+ ctxt.Out.Flush()
ctxt.Out.Write(ld.Elfstrdat)
if ctxt.LinkMode == ld.LinkExternal {
@@ -219,6 +220,7 @@ func asmb2(ctxt *ld.Link) {
ld.Asmbelf(ctxt, int64(symo))
}
+ ctxt.Out.Flush()
if *ld.FlagC {
fmt.Printf("textsize=%d\n", ld.Segtext.Filelen)
fmt.Printf("datsize=%d\n", ld.Segdata.Filelen)
diff --git a/src/cmd/link/internal/mips64/asm.go b/src/cmd/link/internal/mips64/asm.go
index 0a2a3c11f3eff41195fac9ef1b7c339957964853..1b2914eea398f5af4516360f062f6eb299201149 100644
--- a/src/cmd/link/internal/mips64/asm.go
+++ b/src/cmd/link/internal/mips64/asm.go
@@ -223,6 +223,7 @@ func asmb2(ctxt *ld.Link) {
default:
if ctxt.IsELF {
ld.Asmelfsym(ctxt)
+ ctxt.Out.Flush()
ctxt.Out.Write(ld.Elfstrdat)
if ctxt.LinkMode == ld.LinkExternal {
@@ -232,11 +233,13 @@ func asmb2(ctxt *ld.Link) {
case objabi.Hplan9:
ld.Asmplan9sym(ctxt)
+ ctxt.Out.Flush()
sym := ctxt.Syms.Lookup("pclntab", 0)
if sym != nil {
ld.Lcsize = int32(len(sym.P))
ctxt.Out.Write(sym.P)
+ ctxt.Out.Flush()
}
}
}
@@ -265,6 +268,7 @@ func asmb2(ctxt *ld.Link) {
ld.Asmbelf(ctxt, int64(symo))
}
+ ctxt.Out.Flush()
if *ld.FlagC {
fmt.Printf("textsize=%d\n", ld.Segtext.Filelen)
fmt.Printf("datsize=%d\n", ld.Segdata.Filelen)
diff --git a/src/cmd/link/internal/ppc64/asm.go b/src/cmd/link/internal/ppc64/asm.go
index 0e3a69143225754eff3ffa24d9c6aac762ae26ae..d86738538d9cdca71e03656a6d1093995d729094 100644
--- a/src/cmd/link/internal/ppc64/asm.go
+++ b/src/cmd/link/internal/ppc64/asm.go
@@ -1130,6 +1130,7 @@ func asmb2(ctxt *ld.Link) {
default:
if ctxt.IsELF {
ld.Asmelfsym(ctxt)
+ ctxt.Out.Flush()
ctxt.Out.Write(ld.Elfstrdat)
if ctxt.LinkMode == ld.LinkExternal {
@@ -1139,15 +1140,18 @@ func asmb2(ctxt *ld.Link) {
case objabi.Hplan9:
ld.Asmplan9sym(ctxt)
+ ctxt.Out.Flush()
sym := ctxt.Syms.Lookup("pclntab", 0)
if sym != nil {
ld.Lcsize = int32(len(sym.P))
ctxt.Out.Write(sym.P)
+ ctxt.Out.Flush()
}
case objabi.Haix:
// symtab must be added once sections have been created in ld.Asmbxcoff
+ ctxt.Out.Flush()
}
}
@@ -1176,6 +1180,7 @@ func asmb2(ctxt *ld.Link) {
ld.Asmbxcoff(ctxt, int64(fileoff))
}
+ ctxt.Out.Flush()
if *ld.FlagC {
fmt.Printf("textsize=%d\n", ld.Segtext.Filelen)
fmt.Printf("datsize=%d\n", ld.Segdata.Filelen)
diff --git a/src/cmd/link/internal/riscv64/asm.go b/src/cmd/link/internal/riscv64/asm.go
index 51cc5980c89a75a76a93fb4aab1251a2252fa685..db3b602b848af45aae392a07b7014435e1a363e9 100644
--- a/src/cmd/link/internal/riscv64/asm.go
+++ b/src/cmd/link/internal/riscv64/asm.go
@@ -142,6 +142,7 @@ func asmb2(ctxt *ld.Link) {
ctxt.Out.SeekSet(int64(symo))
ld.Asmelfsym(ctxt)
+ ctxt.Out.Flush()
ctxt.Out.Write(ld.Elfstrdat)
if ctxt.LinkMode == ld.LinkExternal {
@@ -156,6 +157,7 @@ func asmb2(ctxt *ld.Link) {
default:
ld.Errorf(nil, "unsupported operating system")
}
+ ctxt.Out.Flush()
if *ld.FlagC {
fmt.Printf("textsize=%d\n", ld.Segtext.Filelen)
diff --git a/src/cmd/link/internal/s390x/asm.go b/src/cmd/link/internal/s390x/asm.go
index 9b6be28421f144d554e53a48d2bf4daa49b90250..5d55a190726615e7489dcb78cd15bf47284a6145 100644
--- a/src/cmd/link/internal/s390x/asm.go
+++ b/src/cmd/link/internal/s390x/asm.go
@@ -515,6 +515,7 @@ func asmb2(ctxt *ld.Link) {
ctxt.Out.SeekSet(int64(symo))
ld.Asmelfsym(ctxt)
+ ctxt.Out.Flush()
ctxt.Out.Write(ld.Elfstrdat)
if ctxt.LinkMode == ld.LinkExternal {
@@ -530,6 +531,7 @@ func asmb2(ctxt *ld.Link) {
ld.Asmbelf(ctxt, int64(symo))
}
+ ctxt.Out.Flush()
if *ld.FlagC {
fmt.Printf("textsize=%d\n", ld.Segtext.Filelen)
fmt.Printf("datsize=%d\n", ld.Segdata.Filelen)
diff --git a/src/cmd/link/internal/wasm/asm.go b/src/cmd/link/internal/wasm/asm.go
index 7f8742d00823648701324e5eb06bb437db53c099..550ed5bc3c43276bd94380ad61e969e9dfcc5028 100644
--- a/src/cmd/link/internal/wasm/asm.go
+++ b/src/cmd/link/internal/wasm/asm.go
@@ -187,6 +187,8 @@ func asmb2(ctxt *ld.Link) {
if !*ld.FlagS {
writeNameSec(ctxt, len(hostImports), fns)
}
+
+ ctxt.Out.Flush()
}
func lookupType(sig *wasmFuncType, types *[]*wasmFuncType) uint32 {
diff --git a/src/cmd/link/internal/x86/asm.go b/src/cmd/link/internal/x86/asm.go
index 7dcdda0fa80d4539a605acf60ba7b8d67bb63a58..cbc79c987b9323654d180eb7c2f17c24c76ec868 100644
--- a/src/cmd/link/internal/x86/asm.go
+++ b/src/cmd/link/internal/x86/asm.go
@@ -646,6 +646,7 @@ func asmb2(ctxt *ld.Link) {
default:
if ctxt.IsELF {
ld.Asmelfsym(ctxt)
+ ctxt.Out.Flush()
ctxt.Out.Write(ld.Elfstrdat)
if ctxt.LinkMode == ld.LinkExternal {
@@ -655,11 +656,13 @@ func asmb2(ctxt *ld.Link) {
case objabi.Hplan9:
ld.Asmplan9sym(ctxt)
+ ctxt.Out.Flush()
sym := ctxt.Syms.Lookup("pclntab", 0)
if sym != nil {
ld.Lcsize = int32(len(sym.P))
ctxt.Out.Write(sym.P)
+ ctxt.Out.Flush()
}
case objabi.Hwindows:
@@ -699,4 +702,6 @@ func asmb2(ctxt *ld.Link) {
case objabi.Hwindows:
ld.Asmbpe(ctxt)
}
+
+ ctxt.Out.Flush()
}