cmd/link/internal/ld: move ld.Cpos to coutbuf.Offset

This change moves the ld.Cpos function to a method on coutbuf. This is
part of a larger change that makes ld.outbuf look more like a bio.Buf in
an effort to eventually replace the former with the latter.

Change-Id: I506f7131935a2aa903fa302a0fab0c5be50220fd
Reviewed-on: https://go-review.googlesource.com/27578
Run-TryBot: Dave Cheney <dave@cheney.net>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

src/cmd/link/internal/ld/data.go

@@ -746,7 +746,7 @@ func Codeblk(ctxt *Link, addr int64, size int64) {
 }
 func CodeblkPad(ctxt *Link, addr int64, size int64, pad []byte) {
 	if *flagA {
-		fmt.Fprintf(ctxt.Bso, "codeblk [%#x,%#x) at offset %#x\n", addr, addr+size, Cpos())
+		fmt.Fprintf(ctxt.Bso, "codeblk [%#x,%#x) at offset %#x\n", addr, addr+size, coutbuf.Offset())
 	}
 
 	blk(ctxt, ctxt.Textp, addr, size, pad)
@@ -857,7 +857,7 @@ func blk(ctxt *Link, syms []*Symbol, addr, size int64, pad []byte) {
 
 func Datblk(ctxt *Link, addr int64, size int64) {
 	if *flagA {
-		fmt.Fprintf(ctxt.Bso, "datblk [%#x,%#x) at offset %#x\n", addr, addr+size, Cpos())
+		fmt.Fprintf(ctxt.Bso, "datblk [%#x,%#x) at offset %#x\n", addr, addr+size, coutbuf.Offset())
 	}
 
 	blk(ctxt, datap, addr, size, zeros[:])
@@ -928,7 +928,7 @@ func Datblk(ctxt *Link, addr int64, size int64) {
 
 func Dwarfblk(ctxt *Link, addr int64, size int64) {
 	if *flagA {
-		fmt.Fprintf(ctxt.Bso, "dwarfblk [%#x,%#x) at offset %#x\n", addr, addr+size, Cpos())
+		fmt.Fprintf(ctxt.Bso, "dwarfblk [%#x,%#x) at offset %#x\n", addr, addr+size, coutbuf.Offset())
 	}
 
 	blk(ctxt, dwarfp, addr, size, zeros[:])

src/cmd/link/internal/ld/elf.go

@@ -1729,7 +1729,7 @@ func elfrelocsect(ctxt *Link, sect *Section, syms []*Symbol) {
 		return
 	}
 
-	sect.Reloff = uint64(Cpos())
+	sect.Reloff = uint64(coutbuf.Offset())
 	for i, s := range syms {
 		if !s.Attr.Reachable() {
 			continue
@@ -1768,11 +1768,11 @@ func elfrelocsect(ctxt *Link, sect *Section, syms []*Symbol) {
 		}
 	}
 
-	sect.Rellen = uint64(Cpos()) - sect.Reloff
+	sect.Rellen = uint64(coutbuf.Offset()) - sect.Reloff
 }
 
 func Elfemitreloc(ctxt *Link) {
-	for Cpos()&7 != 0 {
+	for coutbuf.Offset()&7 != 0 {
 		Cput(0)
 	}
 

src/cmd/link/internal/ld/lib.go

@@ -229,6 +229,10 @@ func (w *outBuf) WriteString(s string) (n int, err error) {
 	return n, err
 }
 
+func (w *outBuf) Offset() int64 {
+	return w.off
+}
+
 var coutbuf outBuf
 
 const pkgname = "__.PKGDEF"
@@ -1771,10 +1775,6 @@ func Cflush() {
 	}
 }
 
-func Cpos() int64 {
-	return coutbuf.off
-}
-
 func Cseek(p int64) {
 	if p == coutbuf.off {
 		return

src/cmd/link/internal/ld/macho.go

@@ -186,7 +186,7 @@ var dylib []string
 var linkoff int64
 
 func machowrite() int {
-	o1 := Cpos()
+	o1 := coutbuf.Offset()
 
 	loadsize := 4 * 4 * ndebug
 	for i := 0; i < len(load); i++ {
@@ -291,7 +291,7 @@ func machowrite() int {
 		}
 	}
 
-	return int(Cpos() - o1)
+	return int(coutbuf.Offset() - o1)
 }
 
 func (ctxt *Link) domacho() {
@@ -815,7 +815,7 @@ func machorelocsect(ctxt *Link, sect *Section, syms []*Symbol) {
 		return
 	}
 
-	sect.Reloff = uint64(Cpos())
+	sect.Reloff = uint64(coutbuf.Offset())
 	for i, s := range syms {
 		if !s.Attr.Reachable() {
 			continue
@@ -847,11 +847,11 @@ func machorelocsect(ctxt *Link, sect *Section, syms []*Symbol) {
 		}
 	}
 
-	sect.Rellen = uint64(Cpos()) - sect.Reloff
+	sect.Rellen = uint64(coutbuf.Offset()) - sect.Reloff
 }
 
 func Machoemitreloc(ctxt *Link) {
-	for Cpos()&7 != 0 {
+	for coutbuf.Offset()&7 != 0 {
 		Cput(0)
 	}
 

src/cmd/link/internal/ld/pe.go

@@ -570,7 +570,7 @@ func peimporteddlls() []string {
 }
 
 func addimports(ctxt *Link, datsect *IMAGE_SECTION_HEADER) {
-	startoff := Cpos()
+	startoff := coutbuf.Offset()
 	dynamic := Linklookup(ctxt, ".windynamic", 0)
 
 	// skip import descriptor table (will write it later)
@@ -583,7 +583,7 @@ func addimports(ctxt *Link, datsect *IMAGE_SECTION_HEADER) {
 
 	// write dll names
 	for d := dr; d != nil; d = d.next {
-		d.nameoff = uint64(Cpos()) - uint64(startoff)
+		d.nameoff = uint64(coutbuf.Offset()) - uint64(startoff)
 		strput(d.name)
 	}
 
@@ -591,18 +591,18 @@ func addimports(ctxt *Link, datsect *IMAGE_SECTION_HEADER) {
 	var m *Imp
 	for d := dr; d != nil; d = d.next {
 		for m = d.ms; m != nil; m = m.next {
-			m.off = uint64(nextsectoff) + uint64(Cpos()) - uint64(startoff)
+			m.off = uint64(nextsectoff) + uint64(coutbuf.Offset()) - uint64(startoff)
 			Wputl(0) // hint
 			strput(m.s.Extname)
 		}
 	}
 
 	// write OriginalFirstThunks
-	oftbase := uint64(Cpos()) - uint64(startoff)
+	oftbase := uint64(coutbuf.Offset()) - uint64(startoff)
 
-	n = uint64(Cpos())
+	n = uint64(coutbuf.Offset())
 	for d := dr; d != nil; d = d.next {
-		d.thunkoff = uint64(Cpos()) - n
+		d.thunkoff = uint64(coutbuf.Offset()) - n
 		for m = d.ms; m != nil; m = m.next {
 			if pe64 != 0 {
 				Vputl(m.off)
@@ -619,13 +619,13 @@ func addimports(ctxt *Link, datsect *IMAGE_SECTION_HEADER) {
 	}
 
 	// add pe section and pad it at the end
-	n = uint64(Cpos()) - uint64(startoff)
+	n = uint64(coutbuf.Offset()) - uint64(startoff)
 
 	isect := addpesection(ctxt, ".idata", int(n), int(n))
 	isect.Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE
 	chksectoff(ctxt, isect, startoff)
 	strnput("", int(uint64(isect.SizeOfRawData)-n))
-	endoff := Cpos()
+	endoff := coutbuf.Offset()
 
 	// write FirstThunks (allocated in .data section)
 	ftbase := uint64(dynamic.Value) - uint64(datsect.VirtualAddress) - PEBASE
@@ -666,7 +666,6 @@ func addimports(ctxt *Link, datsect *IMAGE_SECTION_HEADER) {
 
 	// update data directory
 	dd[IMAGE_DIRECTORY_ENTRY_IMPORT].VirtualAddress = isect.VirtualAddress
-
 	dd[IMAGE_DIRECTORY_ENTRY_IMPORT].Size = isect.VirtualSize
 	dd[IMAGE_DIRECTORY_ENTRY_IAT].VirtualAddress = uint32(dynamic.Value - PEBASE)
 	dd[IMAGE_DIRECTORY_ENTRY_IAT].Size = uint32(dynamic.Size)
@@ -712,7 +711,7 @@ func addexports(ctxt *Link) {
 
 	sect := addpesection(ctxt, ".edata", size, size)
 	sect.Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ
-	chksectoff(ctxt, sect, Cpos())
+	chksectoff(ctxt, sect, coutbuf.Offset())
 	va := int(sect.VirtualAddress)
 	dd[IMAGE_DIRECTORY_ENTRY_EXPORT].VirtualAddress = uint32(va)
 	dd[IMAGE_DIRECTORY_ENTRY_EXPORT].Size = sect.VirtualSize
@@ -772,7 +771,7 @@ func perelocsect(ctxt *Link, sect *Section, syms []*Symbol) int {
 
 	relocs := 0
 
-	sect.Reloff = uint64(Cpos())
+	sect.Reloff = uint64(coutbuf.Offset())
 	for i, s := range syms {
 		if !s.Attr.Reachable() {
 			continue
@@ -814,18 +813,18 @@ func perelocsect(ctxt *Link, sect *Section, syms []*Symbol) int {
 		}
 	}
 
-	sect.Rellen = uint64(Cpos()) - sect.Reloff
+	sect.Rellen = uint64(coutbuf.Offset()) - sect.Reloff
 
 	return relocs
 }
 
 // peemitreloc emits relocation entries for go.o in external linking.
 func peemitreloc(ctxt *Link, text, data, ctors *IMAGE_SECTION_HEADER) {
-	for Cpos()&7 != 0 {
+	for coutbuf.Offset()&7 != 0 {
 		Cput(0)
 	}
 
-	text.PointerToRelocations = uint32(Cpos())
+	text.PointerToRelocations = uint32(coutbuf.Offset())
 	// first entry: extended relocs
 	Lputl(0) // placeholder for number of relocation + 1
 	Lputl(0)
@@ -836,7 +835,7 @@ func peemitreloc(ctxt *Link, text, data, ctors *IMAGE_SECTION_HEADER) {
 		n += perelocsect(ctxt, sect, datap)
 	}
 
-	cpos := Cpos()
+	cpos := coutbuf.Offset()
 	Cseek(int64(text.PointerToRelocations))
 	Lputl(uint32(n))
 	Cseek(cpos)
@@ -859,7 +858,7 @@ func peemitreloc(ctxt *Link, text, data, ctors *IMAGE_SECTION_HEADER) {
 		n += perelocsect(ctxt, sect, datap)
 	}
 
-	cpos = Cpos()
+	cpos = coutbuf.Offset()
 	Cseek(int64(data.PointerToRelocations))
 	Lputl(uint32(n))
 	Cseek(cpos)
@@ -873,7 +872,7 @@ func peemitreloc(ctxt *Link, text, data, ctors *IMAGE_SECTION_HEADER) {
 
 	dottext := Linklookup(ctxt, ".text", 0)
 	ctors.NumberOfRelocations = 1
-	ctors.PointerToRelocations = uint32(Cpos())
+	ctors.PointerToRelocations = uint32(coutbuf.Offset())
 	sectoff := ctors.VirtualAddress
 	Lputl(sectoff)
 	Lputl(uint32(dottext.Dynid))
@@ -1017,7 +1016,7 @@ func writePESymTableRecords(ctxt *Link) int {
 }
 
 func addpesymtable(ctxt *Link) {
-	symtabStartPos := Cpos()
+	symtabStartPos := coutbuf.Offset()
 
 	// write COFF symbol table
 	var symcnt int
@@ -1063,7 +1062,7 @@ func addpersrc(ctxt *Link) {
 
 	h := addpesection(ctxt, ".rsrc", int(rsrcsym.Size), int(rsrcsym.Size))
 	h.Characteristics = IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE | IMAGE_SCN_CNT_INITIALIZED_DATA
-	chksectoff(ctxt, h, Cpos())
+	chksectoff(ctxt, h, coutbuf.Offset())
 
 	// relocation
 	var p []byte
@@ -1113,7 +1112,7 @@ func addinitarray(ctxt *Link) (c *IMAGE_SECTION_HEADER) {
 	c.SizeOfRawData = uint32(size)
 
 	Cseek(int64(c.PointerToRawData))
-	chksectoff(ctxt, c, Cpos())
+	chksectoff(ctxt, c, coutbuf.Offset())
 	init_entry := Linklookup(ctxt, *flagEntrySymbol, 0)
 	addr := uint64(init_entry.Value) - init_entry.Sect.Vaddr