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// Derived from Inferno utils/6l/l.h and related files.
// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/6l/l.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 (
"bufio"
"cmd/internal/objabi"
"cmd/internal/sys"
"cmd/link/internal/loader"
"cmd/link/internal/sym"
"debug/elf"
"fmt"
)
type Shlib struct {
Path string
Hash []byte
Deps []string
File *elf.File
}
// Link holds the context for writing object code from a compiler
// or for reading that input into the linker.
type Link struct {
Target
ErrorReporter
ArchSyms
outSem chan int // limits the number of output writers
Out *OutBuf
version int // current version number for static/file-local symbols
Debugvlog int
Bso *bufio.Writer
Loaded bool // set after all inputs have been loaded as symbols
compressDWARF bool
Libdir []string
Library []*sym.Library
LibraryByPkg map[string]*sym.Library
Shlibs []Shlib
Textp []loader.Sym
Moduledata loader.Sym
PackageFile map[string]string
PackageShlib map[string]string
tramps []loader.Sym // trampolines
compUnits []*sym.CompilationUnit // DWARF compilation units
runtimeCU *sym.CompilationUnit // One of the runtime CUs, the last one seen.
loader *loader.Loader
cgodata []cgodata // cgo directives to load, three strings are args for loadcgo
datap []loader.Sym
dynexp []loader.Sym
// Elf symtab variables.
numelfsym int // starts at 0, 1 is reserved
// These are symbols that created and written by the linker.
// Rather than creating a symbol, and writing all its data into the heap,
// you can create a symbol, and just a generation function will be called
// after the symbol's been created in the output mmap.
generatorSyms map[loader.Sym]generatorFunc
}
type cgodata struct {
file string
pkg string
directives [][]string
}
// The smallest possible offset from the hardware stack pointer to a local
// variable on the stack. Architectures that use a link register save its value
// on the stack in the function prologue and so always have a pointer between
// the hardware stack pointer and the local variable area.
func (ctxt *Link) FixedFrameSize() int64 {
switch ctxt.Arch.Family {
case sys.AMD64, sys.I386:
return 0
case sys.PPC64:
// PIC code on ppc64le requires 32 bytes of stack, and it's easier to
// just use that much stack always on ppc64x.
return int64(4 * ctxt.Arch.PtrSize)
default:
return int64(ctxt.Arch.PtrSize)
}
}
func (ctxt *Link) Logf(format string, args ...interface{}) {
fmt.Fprintf(ctxt.Bso, format, args...)
ctxt.Bso.Flush()
}
func addImports(ctxt *Link, l *sym.Library, pn string) {
pkg := objabi.PathToPrefix(l.Pkg)
for _, imp := range l.Autolib {
lib := addlib(ctxt, pkg, pn, imp.Pkg, imp.Fingerprint)
if lib != nil {
l.Imports = append(l.Imports, lib)
}
}
l.Autolib = nil
}
// Allocate a new version (i.e. symbol namespace).
func (ctxt *Link) IncVersion() int {
ctxt.version++
return ctxt.version - 1
}
// returns the maximum version number
func (ctxt *Link) MaxVersion() int {
return ctxt.version
}
// generatorFunc is a convenience type.
// Linker created symbols that are large, and shouldn't really live in the
// heap can define a generator function, and their bytes can be generated
// directly in the output mmap.
//
// Generator symbols shouldn't grow the symbol size, and might be called in
// parallel in the future.
//
// Generator Symbols have their Data set to the mmapped area when the
// generator is called.
type generatorFunc func(*Link, loader.Sym)
// createGeneratorSymbol is a convenience method for creating a generator
// symbol.
func (ctxt *Link) createGeneratorSymbol(name string, version int, t sym.SymKind, size int64, gen generatorFunc) loader.Sym {
ldr := ctxt.loader
s := ldr.LookupOrCreateSym(name, version)
ldr.SetIsGeneratedSym(s, true)
sb := ldr.MakeSymbolUpdater(s)
sb.SetType(t)
sb.SetSize(size)
ctxt.generatorSyms[s] = gen
return s
}
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