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Diffstat (limited to 'src/cmd/link/internal/ld/ar.go')
| -rw-r--r-- | src/cmd/link/internal/ld/ar.go | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/src/cmd/link/internal/ld/ar.go b/src/cmd/link/internal/ld/ar.go new file mode 100644 index 0000000..e4fd591 --- /dev/null +++ b/src/cmd/link/internal/ld/ar.go @@ -0,0 +1,191 @@ +// Inferno utils/include/ar.h +// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/include/ar.h +// +// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. +// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net) +// Portions Copyright © 1997-1999 Vita Nuova Limited +// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com) +// Portions Copyright © 2004,2006 Bruce Ellis +// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net) +// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others +// Portions Copyright © 2009 The Go Authors. All rights reserved. +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in +// all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. + +package ld + +import ( + "cmd/internal/bio" + "cmd/internal/objabi" + "cmd/link/internal/sym" + "encoding/binary" + "fmt" + "io" + "os" +) + +const ( + SARMAG = 8 + SAR_HDR = 16 + 44 +) + +const ( + ARMAG = "!<arch>\n" +) + +type ArHdr struct { + name string + date string + uid string + gid string + mode string + size string + fmag string +} + +// hostArchive reads an archive file holding host objects and links in +// required objects. The general format is the same as a Go archive +// file, but it has an armap listing symbols and the objects that +// define them. This is used for the compiler support library +// libgcc.a. +func hostArchive(ctxt *Link, name string) { + f, err := bio.Open(name) + if err != nil { + if os.IsNotExist(err) { + // It's OK if we don't have a libgcc file at all. + if ctxt.Debugvlog != 0 { + ctxt.Logf("skipping libgcc file: %v\n", err) + } + return + } + Exitf("cannot open file %s: %v", name, err) + } + defer f.Close() + + var magbuf [len(ARMAG)]byte + if _, err := io.ReadFull(f, magbuf[:]); err != nil { + Exitf("file %s too short", name) + } + + if string(magbuf[:]) != ARMAG { + Exitf("%s is not an archive file", name) + } + + var arhdr ArHdr + l := nextar(f, f.Offset(), &arhdr) + if l <= 0 { + Exitf("%s missing armap", name) + } + + var armap archiveMap + if arhdr.name == "/" || arhdr.name == "/SYM64/" { + armap = readArmap(name, f, arhdr) + } else { + Exitf("%s missing armap", name) + } + + loaded := make(map[uint64]bool) + any := true + for any { + var load []uint64 + returnAllUndefs := -1 + undefs := ctxt.loader.UndefinedRelocTargets(returnAllUndefs) + for _, symIdx := range undefs { + name := ctxt.loader.SymName(symIdx) + if off := armap[name]; off != 0 && !loaded[off] { + load = append(load, off) + loaded[off] = true + } + } + + for _, off := range load { + l := nextar(f, int64(off), &arhdr) + if l <= 0 { + Exitf("%s missing archive entry at offset %d", name, off) + } + pname := fmt.Sprintf("%s(%s)", name, arhdr.name) + l = atolwhex(arhdr.size) + + libgcc := sym.Library{Pkg: "libgcc"} + h := ldobj(ctxt, f, &libgcc, l, pname, name) + f.MustSeek(h.off, 0) + h.ld(ctxt, f, h.pkg, h.length, h.pn) + } + + any = len(load) > 0 + } +} + +// archiveMap is an archive symbol map: a mapping from symbol name to +// offset within the archive file. +type archiveMap map[string]uint64 + +// readArmap reads the archive symbol map. +func readArmap(filename string, f *bio.Reader, arhdr ArHdr) archiveMap { + is64 := arhdr.name == "/SYM64/" + wordSize := 4 + if is64 { + wordSize = 8 + } + + contents := make([]byte, atolwhex(arhdr.size)) + if _, err := io.ReadFull(f, contents); err != nil { + Exitf("short read from %s", filename) + } + + var c uint64 + if is64 { + c = binary.BigEndian.Uint64(contents) + } else { + c = uint64(binary.BigEndian.Uint32(contents)) + } + contents = contents[wordSize:] + + ret := make(archiveMap) + + names := contents[c*uint64(wordSize):] + for i := uint64(0); i < c; i++ { + n := 0 + for names[n] != 0 { + n++ + } + name := string(names[:n]) + names = names[n+1:] + + // For Mach-O and PE/386 files we strip a leading + // underscore from the symbol name. + if objabi.GOOS == "darwin" || objabi.GOOS == "ios" || (objabi.GOOS == "windows" && objabi.GOARCH == "386") { + if name[0] == '_' && len(name) > 1 { + name = name[1:] + } + } + + var off uint64 + if is64 { + off = binary.BigEndian.Uint64(contents) + } else { + off = uint64(binary.BigEndian.Uint32(contents)) + } + contents = contents[wordSize:] + + ret[name] = off + } + + return ret +} |