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// Derived from Inferno utils/6l/l.h and related files.
// https://bitbucket.org/inferno-os/inferno-os/src/default/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/obj"
"cmd/internal/sys"
"debug/elf"
"fmt"
)
// Symbol is an entry in the symbol table.
type Symbol struct {
Name string
Extname string
Type obj.SymKind
Version int16
Attr Attribute
Localentry uint8
Dynid int32
Plt int32
Got int32
Align int32
Elfsym int32
LocalElfsym int32
Value int64
Size int64
// ElfType is set for symbols read from shared libraries by ldshlibsyms. It
// is not set for symbols defined by the packages being linked or by symbols
// read by ldelf (and so is left as elf.STT_NOTYPE).
ElfType elf.SymType
Sub *Symbol
Outer *Symbol
Gotype *Symbol
Reachparent *Symbol
File string
Dynimplib string
Dynimpvers string
Sect *Section
FuncInfo *FuncInfo
// P contains the raw symbol data.
P []byte
R []Reloc
}
func (s *Symbol) String() string {
if s.Version == 0 {
return s.Name
}
return fmt.Sprintf("%s<%d>", s.Name, s.Version)
}
func (s *Symbol) ElfsymForReloc() int32 {
// If putelfsym created a local version of this symbol, use that in all
// relocations.
if s.LocalElfsym != 0 {
return s.LocalElfsym
} else {
return s.Elfsym
}
}
// Attribute is a set of common symbol attributes.
type Attribute int16
const (
AttrDuplicateOK Attribute = 1 << iota
AttrExternal
AttrNoSplit
AttrReachable
AttrCgoExportDynamic
AttrCgoExportStatic
AttrSpecial
AttrStackCheck
AttrHidden
AttrOnList
AttrLocal
AttrReflectMethod
AttrMakeTypelink
)
func (a Attribute) DuplicateOK() bool { return a&AttrDuplicateOK != 0 }
func (a Attribute) External() bool { return a&AttrExternal != 0 }
func (a Attribute) NoSplit() bool { return a&AttrNoSplit != 0 }
func (a Attribute) Reachable() bool { return a&AttrReachable != 0 }
func (a Attribute) CgoExportDynamic() bool { return a&AttrCgoExportDynamic != 0 }
func (a Attribute) CgoExportStatic() bool { return a&AttrCgoExportStatic != 0 }
func (a Attribute) Special() bool { return a&AttrSpecial != 0 }
func (a Attribute) StackCheck() bool { return a&AttrStackCheck != 0 }
func (a Attribute) Hidden() bool { return a&AttrHidden != 0 }
func (a Attribute) OnList() bool { return a&AttrOnList != 0 }
func (a Attribute) Local() bool { return a&AttrLocal != 0 }
func (a Attribute) ReflectMethod() bool { return a&AttrReflectMethod != 0 }
func (a Attribute) MakeTypelink() bool { return a&AttrMakeTypelink != 0 }
func (a Attribute) CgoExport() bool {
return a.CgoExportDynamic() || a.CgoExportStatic()
}
func (a *Attribute) Set(flag Attribute, value bool) {
if value {
*a |= flag
} else {
*a &^= flag
}
}
// Reloc is a relocation.
//
// The typical Reloc rewrites part of a symbol at offset Off to address Sym.
// A Reloc is stored in a slice on the Symbol it rewrites.
//
// Relocations are generated by the compiler as the type
// cmd/internal/obj.Reloc, which is encoded into the object file wire
// format and decoded by the linker into this type. A separate type is
// used to hold linker-specific state about the relocation.
//
// Some relocations are created by cmd/link.
type Reloc struct {
Off int32 // offset to rewrite
Siz uint8 // number of bytes to rewrite, 1, 2, or 4
Done uint8 // set to 1 when relocation is complete
Variant RelocVariant // variation on Type
Type obj.RelocType // the relocation type
Add int64 // addend
Xadd int64 // addend passed to external linker
Sym *Symbol // symbol the relocation addresses
Xsym *Symbol // symbol passed to external linker
}
type Auto struct {
Asym *Symbol
Gotype *Symbol
Aoffset int32
Name int16
}
type Shlib struct {
Path string
Hash []byte
Deps []string
File *elf.File
gcdataAddresses map[*Symbol]uint64
}
// Link holds the context for writing object code from a compiler
// or for reading that input into the linker.
type Link struct {
Syms *Symbols
Arch *sys.Arch
Debugvlog int
Bso *bufio.Writer
Loaded bool // set after all inputs have been loaded as symbols
Tlsg *Symbol
Libdir []string
Library []*Library
Shlibs []Shlib
Tlsoffset int
Textp []*Symbol
Filesyms []*Symbol
Moduledata *Symbol
tramps []*Symbol // trampolines
}
// 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 (l *Link) Logf(format string, args ...interface{}) {
fmt.Fprintf(l.Bso, format, args...)
l.Bso.Flush()
}
type Library struct {
Objref string
Srcref string
File string
Pkg string
Shlib string
hash []byte
imports []*Library
textp []*Symbol // text symbols defined in this library
dupTextSyms []*Symbol // dupok text symbols defined in this library
}
func (l Library) String() string {
return l.Pkg
}
type FuncInfo struct {
Args int32
Locals int32
Autom []Auto
Pcsp Pcdata
Pcfile Pcdata
Pcline Pcdata
Pcdata []Pcdata
Funcdata []*Symbol
Funcdataoff []int64
File []*Symbol
}
type Pcdata struct {
P []byte
}
type Pciter struct {
d Pcdata
p []byte
pc uint32
nextpc uint32
pcscale uint32
value int32
start int
done int
}
// RelocVariant is a linker-internal variation on a relocation.
type RelocVariant uint8
const (
RV_NONE RelocVariant = iota
RV_POWER_LO
RV_POWER_HI
RV_POWER_HA
RV_POWER_DS
// RV_390_DBL is a s390x-specific relocation variant that indicates that
// the value to be placed into the relocatable field should first be
// divided by 2.
RV_390_DBL
RV_CHECK_OVERFLOW RelocVariant = 1 << 7
RV_TYPE_MASK RelocVariant = RV_CHECK_OVERFLOW - 1
)
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