cmd/link: introduce and use peFile.writeFileHeader

Change-Id: I1324b69ab9edb870589197fa601b5764634d42a4
Reviewed-on: https://go-review.googlesource.com/59427
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/src/cmd/link/internal/ld/pe.go b/src/cmd/link/internal/ld/pe.go
index 128f0c9319cd545192b85d6caf4dd82dacb46b04..06b3b0193cceaac2eae11009f550dcac9dc8aaba 100644 (file)
--- a/src/cmd/link/internal/ld/pe.go
+++ b/src/cmd/link/internal/ld/pe.go
@@ -15,16 +15,6 @@ import (
        "strings"
 )
 
-type IMAGE_FILE_HEADER struct {
-       Machine              uint16
-       NumberOfSections     uint16
-       TimeDateStamp        uint32
-       PointerToSymbolTable uint32
-       NumberOfSymbols      uint32
-       SizeOfOptionalHeader uint16
-       Characteristics      uint16
-}
-
 type IMAGE_DATA_DIRECTORY struct {
        VirtualAddress uint32
        Size           uint32
@@ -321,8 +311,6 @@ var PEFILEHEADR int32
 
 var pe64 int
 
-var fh IMAGE_FILE_HEADER
-
 var oh IMAGE_OPTIONAL_HEADER
 
 var oh64 PE64_IMAGE_OPTIONAL_HEADER
@@ -475,7 +463,8 @@ type peFile struct {
        ctorsSect      *peSection
        nextSectOffset uint32
        nextFileOffset uint32
-       symbolCount    int // number of symbol table records written
+       symtabOffset   int64 // offset to the start of symbol table
+       symbolCount    int   // number of symbol table records written
 }
 
 // addSection adds section to the COFF file f.
@@ -756,7 +745,7 @@ func (f *peFile) writeSymbols(ctxt *Link) {
 
 // writeSymbolTableAndStringTable writes out symbol and string tables for peFile f.
 func (f *peFile) writeSymbolTableAndStringTable(ctxt *Link) {
-       symtabStartPos := coutbuf.Offset()
+       f.symtabOffset = coutbuf.Offset()
 
        // write COFF symbol table
        if !*FlagS || Linkmode == LinkExternal {
@@ -771,10 +760,8 @@ func (f *peFile) writeSymbolTableAndStringTable(ctxt *Link) {
                // will also include it in the exe, and that will confuse windows.
                h = f.addSection(".symtab", size, size)
                h.Characteristics = IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_DISCARDABLE
-               h.checkOffset(symtabStartPos)
+               h.checkOffset(f.symtabOffset)
        }
-       fh.PointerToSymbolTable = uint32(symtabStartPos)
-       fh.NumberOfSymbols = uint32(f.symbolCount)
 
        // write COFF string table
        f.stringTable.write()
@@ -783,6 +770,44 @@ func (f *peFile) writeSymbolTableAndStringTable(ctxt *Link) {
        }
 }
 
+// writeFileHeader writes COFF file header for peFile f.
+func (f *peFile) writeFileHeader() {
+       var fh pe.FileHeader
+
+       switch SysArch.Family {
+       default:
+               Exitf("unknown PE architecture: %v", SysArch.Family)
+       case sys.AMD64:
+               fh.Machine = IMAGE_FILE_MACHINE_AMD64
+       case sys.I386:
+               fh.Machine = IMAGE_FILE_MACHINE_I386
+       }
+
+       fh.NumberOfSections = uint16(len(f.sections))
+
+       // Being able to produce identical output for identical input is
+       // much more beneficial than having build timestamp in the header.
+       fh.TimeDateStamp = 0
+
+       if Linkmode == LinkExternal {
+               fh.Characteristics = IMAGE_FILE_LINE_NUMS_STRIPPED
+       } else {
+               fh.Characteristics = IMAGE_FILE_RELOCS_STRIPPED | IMAGE_FILE_EXECUTABLE_IMAGE | IMAGE_FILE_DEBUG_STRIPPED
+       }
+       if pe64 != 0 {
+               fh.SizeOfOptionalHeader = uint16(binary.Size(&oh64))
+               fh.Characteristics |= IMAGE_FILE_LARGE_ADDRESS_AWARE
+       } else {
+               fh.SizeOfOptionalHeader = uint16(binary.Size(&oh))
+               fh.Characteristics |= IMAGE_FILE_32BIT_MACHINE
+       }
+
+       fh.PointerToSymbolTable = uint32(f.symtabOffset)
+       fh.NumberOfSymbols = uint32(f.symbolCount)
+
+       binary.Write(&coutbuf, binary.LittleEndian, &fh)
+}
+
 var pefile peFile
 
 func Peinit(ctxt *Link) {
@@ -809,6 +834,7 @@ func Peinit(ctxt *Link) {
        }
 
        var sh [16]pe.SectionHeader32
+       var fh pe.FileHeader
        PEFILEHEADR = int32(Rnd(int64(len(dosstub)+binary.Size(&fh)+l+binary.Size(&sh)), PEFILEALIGN))
        if Linkmode != LinkExternal {
                PESECTHEADR = int32(Rnd(int64(PEFILEHEADR), PESECTALIGN))
@@ -846,7 +872,7 @@ func pewrite() {
                strnput("PE", 4)
        }
 
-       binary.Write(&coutbuf, binary.LittleEndian, &fh)
+       pefile.writeFileHeader()
 
        if pe64 != 0 {
                binary.Write(&coutbuf, binary.LittleEndian, &oh64)
@@ -1214,10 +1240,7 @@ func Asmbpe(ctxt *Link) {
        switch SysArch.Family {
        default:
                Exitf("unknown PE architecture: %v", SysArch.Family)
-       case sys.AMD64:
-               fh.Machine = IMAGE_FILE_MACHINE_AMD64
-       case sys.I386:
-               fh.Machine = IMAGE_FILE_MACHINE_I386
+       case sys.AMD64, sys.I386:
        }
 
        t := pefile.addSection(".text", int(Segtext.Length), int(Segtext.Length))
@@ -1267,24 +1290,9 @@ func Asmbpe(ctxt *Link) {
                pefile.emitRelocations(ctxt)
        }
 
-       fh.NumberOfSections = uint16(len(pefile.sections))
-
-       // Being able to produce identical output for identical input is
-       // much more beneficial than having build timestamp in the header.
-       fh.TimeDateStamp = 0
-
-       if Linkmode == LinkExternal {
-               fh.Characteristics = IMAGE_FILE_LINE_NUMS_STRIPPED
-       } else {
-               fh.Characteristics = IMAGE_FILE_RELOCS_STRIPPED | IMAGE_FILE_EXECUTABLE_IMAGE | IMAGE_FILE_DEBUG_STRIPPED
-       }
        if pe64 != 0 {
-               fh.SizeOfOptionalHeader = uint16(binary.Size(&oh64))
-               fh.Characteristics |= IMAGE_FILE_LARGE_ADDRESS_AWARE
                oh64.Magic = 0x20b // PE32+
        } else {
-               fh.SizeOfOptionalHeader = uint16(binary.Size(&oh))
-               fh.Characteristics |= IMAGE_FILE_32BIT_MACHINE
                oh.Magic = 0x10b // PE32
                oh.BaseOfData = d.VirtualAddress
        }