golang link 代码
文件路径：/src/cmd/internal/obj/link.go
/ 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 obj
import (
"bufio"
"cmd/internal/dwarf"
"cmd/internal/goobj"
"cmd/internal/objabi"
"cmd/internal/src"
"cmd/internal/sys"
"fmt"
"sync"
"sync/atomic"
)
/ An Addr is an argument to an instruction.
/ The general forms and their encodings are:
/
/ sym±offset(symkind)(reg)(index*scale)
/ Memory reference at address &sym(symkind) + offset + reg + index*scale.
/ Any of sym(symkind), ±offset, (reg), (index*scale), and *scale can be omitted.
/ If (reg) and *scale are both omitted, the resulting expression (index) is parsed as (reg).
/ To force a parsing as index*scale, write (index*1).
/ Encoding:
/ type = TYPE_MEM
/ name = symkind (NAME_AUTO, ...) or 0 (NAME_NONE)
/ sym = sym
/ offset = ±offset
/ reg = reg (REG_*)
/ index = index (REG_*)
/ scale = scale (1, 2, 4, 8)
/
/ $<mem>
/ Effective address of memory reference <mem>, defined above.
/ Encoding: same as memory reference, but type = TYPE_ADDR.
/
/ $<±integer value>
/ This is a special case of $<mem>, in which only ±offset is present.
/ It has a separate type for easy recognition.
/ Encoding:
/ type = TYPE_CONST
/ offset = ±integer value
/
/ *<mem>
/ Indirect reference through memory reference <mem>, defined above.
/ Only used on x86 for CALL/JMP *sym(SB), which calls/jumps to a function
/ pointer stored in the data word sym(SB), not a function named sym(SB).
/ Encoding: same as above, but type = TYPE_INDIR.
/
/ $*$<mem>
/ No longer used.
/ On machines with actual SB registers, $*$<mem> forced the
/ instruction encoding to use a full 32-bit constant, never a
/ reference relative to SB.
/
/ $<floating point literal>
/ Floating point constant value.
/ Encoding:
/ type = TYPE_FCONST
/ val = floating point value
/
/ $<string literal, up to 8 chars>
/ String literal value (raw bytes used for DATA instruction).
/ Encoding:
/ type = TYPE_SCONST
/ val = string
/
/ <symbolic constant name>
/ Special symbolic constants for ARM64, such as conditional flags, tlbi_op and so on.
/ Encoding:
/ type = TYPE_SPECIAL
/ offset = The constant value corresponding to this symbol
/
/ <register name>
/ Any register: integer, floating point, control, segment, and so on.
/ If looking for specific register kind, must check type and reg value range.
/ Encoding:
/ type = TYPE_REG
/ reg = reg (REG_*)
/
/ x(PC)
/ Encoding:
/ type = TYPE_BRANCH
/ val = Prog* reference OR ELSE offset = target pc (branch takes priority)
/
/ $±x-±y
/ Final argument to TEXT, specifying local frame size x and argument size y.
/ In this form, x and y are integer literals only, not arbitrary expressions.
/ This avoids parsing ambiguities due to the use of - as a separator.
/ The ± are optional.
/ If the final argument to TEXT omits the -±y, the encoding should still
/ use TYPE_TEXTSIZE (not TYPE_CONST), with u.argsize = ArgsSizeUnknown.
/ Encoding:
/ type = TYPE_TEXTSIZE
/ offset = x
/ val = int32(y)
/
/ reg<<shift, reg>>shift, reg->shift, reg@>shift
/ Shifted register value, for ARM and ARM64.
/ In this form, reg must be a register and shift can be a register or an integer constant.
/ Encoding:
/ type = TYPE_SHIFT
/ On ARM:
/ offset = (reg&15) | shifttype<<5 | count
/ shifttype = 0, 1, 2, 3 for <<, >>, ->, @>
/ count = (reg&15)<<8 | 1<<4 for a register shift count, (n&31)<<7 for an integer constant.
/ On ARM64:
/ offset = (reg&31)<<16 | shifttype<<22 | (count&63)<<10
/ shifttype = 0, 1, 2 for <<, >>, ->
/
/ (reg, reg)
/ A destination register pair. When used as the last argument of an instruction,
/ this form makes clear that both registers are destinations.
/ Encoding:
/ type = TYPE_REGREG
/ reg = first register
/ offset = second register
/
/ [reg, reg, reg-reg]
/ Register list for ARM, ARM64, 386/AMD64.
/ Encoding:
/ type = TYPE_REGLIST
/ On ARM:
/ offset = bit mask of registers in list; R0 is low bit.
/ On ARM64:
/ offset = register count (Q:size) | arrangement (opcode) | first register
/ On 386/AMD64:
/ reg = range low register
/ offset = 2 packed registers + kind tag (see x86.EncodeRegisterRange)
/
/ reg, reg
/ Register pair for ARM.
/ TYPE_REGREG2
/
/ (reg+reg)
/ Register pair for PPC64.
/ Encoding:
/ type = TYPE_MEM
/ reg = first register
/ index = second register
/ scale = 1
/
/ reg.[US]XT[BHWX]
/ Register extension for ARM64
/ Encoding:
/ type = TYPE_REG
/ reg = REG_[US]XT[BHWX] + register + shift amount
/ offset = ((reg&31) << 16) | (exttype << 13) | (amount<<10)
/
/ reg.<T>
/ Register arrangement for ARM64 SIMD register
/ e.g.: V1.S4, V2.S2, V7.D2, V2.H4, V6.B16
/ Encoding:
/ type = TYPE_REG
/ reg = REG_ARNG + register + arrangement
/
/ reg.<T>[index]
/ Register element for ARM64
/ Encoding:
/ type = TYPE_REG
/ reg = REG_ELEM + register + arrangement
/ index = element index
type Addr struct {
Reg int16
Index int16
Scale int16 / Sometimes holds a register.
Type AddrType
Name AddrName
Class int8
Offset int64
Sym *LSym
/ argument value:
/ for TYPE_SCONST, a string
/ for TYPE_FCONST, a float64
/ for TYPE_BRANCH, a *Prog (optional)
/ for TYPE_TEXTSIZE, an int32 (optional)
Val interface{}
}
type AddrName int8
const (
NAME_NONE AddrName = iota
NAME_EXTERN
NAME_STATIC
NAME_AUTO
NAME_PARAM
/ A reference to name@GOT(SB) is a reference to the entry in the global offset
/ table for 'name'.
NAME_GOTREF
/ Indicates that this is a reference to a TOC anchor.
NAME_TOCREF
)
/go:generate stringer -type AddrType
type AddrType uint8
const (
TYPE_NONE AddrType = iota
TYPE_BRANCH
TYPE_TEXTSIZE
TYPE_MEM
TYPE_CONST
TYPE_FCONST
TYPE_SCONST
TYPE_REG
TYPE_ADDR
TYPE_SHIFT
TYPE_REGREG
TYPE_REGREG2
TYPE_INDIR
TYPE_REGLIST
TYPE_SPECIAL
)
func (a *Addr) Target() *Prog {
if a.Type == TYPE_BRANCH && a.Val != nil {
return a.Val.(*Prog)
}
return nil
}
func (a *Addr) SetTarget(t *Prog) {
if a.Type != TYPE_BRANCH {
panic("setting branch target when type is not TYPE_BRANCH")
}
a.Val = t
}
func (a *Addr) SetConst(v int64) {
a.Sym = nil
a.Type = TYPE_CONST
a.Offset = v
}
/ Prog describes a single machine instruction.
/
/ The general instruction form is:
/
/ (1) As.Scond From [, ...RestArgs], To
/ (2) As.Scond From, Reg [, ...RestArgs], To, RegTo2
/
/ where As is an opcode and the others are arguments:
/ From, Reg are sources, and To, RegTo2 are destinations.
/ RestArgs can hold additional sources and destinations.
/ Usually, not all arguments are present.
/ For example, MOVL R1, R2 encodes using only As=MOVL, From=R1, To=R2.
/ The Scond field holds additional condition bits for systems (like arm)
/ that have generalized conditional execution.
/ (2) form is present for compatibility with older code,
/ to avoid too much changes in a single swing.
/ (1) scheme is enough to express any kind of operand combination.
/
/ Jump instructions use the To.Val field to point to the target *Prog,
/ which must be in the same linked list as the jump instruction.
/
/ The Progs for a given function are arranged in a list linked through the Link field.
/
/ Each Prog is charged to a specific source line in the debug information,
/ specified by Pos.Line().
/ Every Prog has a Ctxt field that defines its context.
/ For performance reasons, Progs are usually bulk allocated, cached, and reused;
/ those bulk allocators should always be used, rather than new(Prog).
/
/ The other fields not yet mentioned are for use by the back ends and should
/ be left zeroed by creators of Prog lists.
type Prog struct {
Ctxt *Link / linker context
Link *Prog / next Prog in linked list
From Addr / first source operand
RestArgs []AddrPos / can pack any operands that not fit into {Prog.From, Prog.To}
To Addr / destination operand (second is RegTo2 below)
Pool *Prog / constant pool entry, for arm,arm64 back ends
Forwd *Prog / for x86 back end
Rel *Prog / for x86, arm back ends
Pc int64 / for back ends or assembler: virtual or actual program counter, depending on phase
Pos src.XPos / source position of this instruction
Spadj int32 / effect of instruction on stack pointer (increment or decrement amount)
As As / assembler opcode
Reg int16 / 2nd source operand
RegTo2 int16 / 2nd destination operand
Mark uint16 / bitmask of arch-specific items
Optab uint16 / arch-specific opcode index
Scond uint8 / bits that describe instruction suffixes (e.g. ARM conditions)
Back uint8 / for x86 back end: backwards branch state
Ft uint8 / for x86 back end: type index of Prog.From
Tt uint8 / for x86 back end: type index of Prog.To
Isize uint8 / for x86 back end: size of the instruction in bytes
}
/ Pos indicates whether the oprand is the source or the destination.
type AddrPos struct {
Addr
Pos OperandPos
}
type OperandPos int8
const (
Source OperandPos = iota
Destination
)
/ From3Type returns p.GetFrom3().Type, or TYPE_NONE when
/ p.GetFrom3() returns nil.
/
/ Deprecated: for the same reasons as Prog.GetFrom3.
func (p *Prog) From3Type() AddrType {
if p.RestArgs == nil {
return TYPE_NONE
}
return p.RestArgs[0].Type
}
/ GetFrom3 returns second source operand (the first is Prog.From).
/ In combination with Prog.From and Prog.To it makes common 3 operand
/ case easier to use.
/
/ Should be used only when RestArgs is set with SetFrom3.
/
/ Deprecated: better use RestArgs directly or define backend-specific getters.
/ Introduced to simplify transition to []Addr.
/ Usage of this is discouraged due to fragility and lack of guarantees.
func (p *Prog) GetFrom3() *Addr {
if p.RestArgs == nil {
return nil
}
return &p.RestArgs[0].Addr
}
/ SetFrom3 assigns []Args{{a, 0}} to p.RestArgs.
/ In pair with Prog.GetFrom3 it can help in emulation of Prog.From3.
/
/ Deprecated: for the same reasons as Prog.GetFrom3.
func (p *Prog) SetFrom3(a Addr) {
p.RestArgs = []AddrPos{{a, Source}}
}
/ SetFrom3Reg calls p.SetFrom3 with a register Addr containing reg.
/
/ Deprecated: for the same reasons as Prog.GetFrom3.
func (p *Prog) SetFrom3Reg(reg int16) {
p.SetFrom3(Addr{Type: TYPE_REG, Reg: reg})
}
/ SetFrom3Const calls p.SetFrom3 with a const Addr containing x.
/
/ Deprecated: for the same reasons as Prog.GetFrom3.
func (p *Prog) SetFrom3Const(off int64) {
p.SetFrom3(Addr{Type: TYPE_CONST, Offset: off})
}
/ SetTo2 assigns []Args{{a, 1}} to p.RestArgs when the second destination
/ operand does not fit into prog.RegTo2.
func (p *Prog) SetTo2(a Addr) {
p.RestArgs = []AddrPos{{a, Destination}}
}
/ GetTo2 returns the second destination operand.
func (p *Prog) GetTo2() *Addr {
if p.RestArgs == nil {
return nil
}
return &p.RestArgs[0].Addr
}
/ SetRestArgs assigns more than one source operands to p.RestArgs.
func (p *Prog) SetRestArgs(args []Addr) {
for i := range args {
p.RestArgs = append(p.RestArgs, AddrPos{args[i], Source})
}
}
/ An As denotes an assembler opcode.
/ There are some portable opcodes, declared here in package obj,
/ that are common to all architectures.
/ However, the majority of opcodes are arch-specific
/ and are declared in their respective architecture's subpackage.
type As int16
/ These are the portable opcodes.
const (
AXXX As = iota
ACALL
ADUFFCOPY
ADUFFZERO
AEND
AFUNCDATA
AJMP
ANOP
APCALIGN
APCDATA
ARET
AGETCALLERPC
ATEXT
AUNDEF
A_ARCHSPECIFIC
)
/ Each architecture is allotted a distinct subspace of opcode values
/ for declaring its arch-specific opcodes.
/ Within this subspace, the first arch-specific opcode should be
/ at offset A_ARCHSPECIFIC.
/
/ Subspaces are aligned to a power of two so opcodes can be masked
/ with AMask and used as compact array indices.
const (
ABase386 = (1 + iota) << 11
ABaseARM
ABaseAMD64
ABasePPC64
ABaseARM64
ABaseMIPS
ABaseLoong64
ABaseRISCV
ABaseS390X
ABaseWasm
AllowedOpCodes = 1 << 11 / The number of opcodes available for any given architecture.
AMask = AllowedOpCodes - 1 / AND with this to use the opcode as an array index.
)
/ An LSym is the sort of symbol that is written to an object file.
/ It represents Go symbols in a flat pkg+"."+name namespace.
type LSym struct {
Name string
Type objabi.SymKind
Attribute
Size int64
Gotype *LSym
P []byte
R []Reloc
Extra *interface{} / *FuncInfo or *FileInfo, if present
Pkg string
PkgIdx int32
SymIdx int32
}
/ A FuncInfo contains extra fields for STEXT symbols.
type FuncInfo struct {
Args int32
Locals int32
Align int32
FuncID objabi.FuncID
FuncFlag objabi.FuncFlag
Text *Prog
Autot map[*LSym]struct{}
Pcln Pcln
InlMarks []InlMark
spills []RegSpill
dwarfInfoSym *LSym
dwarfLocSym *LSym
dwarfRangesSym *LSym
dwarfAbsFnSym *LSym
dwarfDebugLinesSym *LSym
GCArgs *LSym
GCLocals *LSym
StackObjects *LSym
OpenCodedDeferInfo *LSym
ArgInfo *LSym / argument info for traceback
ArgLiveInfo *LSym / argument liveness info for traceback
WrapInfo *LSym / for wrapper, info of wrapped function
JumpTables []JumpTable
FuncInfoSym *LSym
}
/ JumpTable represents a table used for implementing multi-way
/ computed branching, used typically for implementing switches.
/ Sym is the table itself, and Targets is a list of target
/ instructions to go to for the computed branch index.
type JumpTable struct {
Sym *LSym
Targets []*Prog
}
/ NewFuncInfo allocates and returns a FuncInfo for LSym.
func (s *LSym) NewFuncInfo() *FuncInfo {
if s.Extra != nil {
panic(fmt.Sprintf("invalid use of LSym - NewFuncInfo with Extra of type %T", *s.Extra))
}
f := new(FuncInfo)
s.Extra = new(interface{})
*s.Extra = f
return f
}
/ Func returns the *FuncInfo associated with s, or else nil.
func (s *LSym) Func() *FuncInfo {
if s.Extra == nil {
return nil
}
f, _ := (*s.Extra).(*FuncInfo)
return f
}
/ A FileInfo contains extra fields for SDATA symbols backed by files.
/ (If LSym.Extra is a *FileInfo, LSym.P == nil.)
type FileInfo struct {
Name string / name of file to read into object file
Size int64 / length of file
}
/ NewFileInfo allocates and returns a FileInfo for LSym.
func (s *LSym) NewFileInfo() *FileInfo {
if s.Extra != nil {
panic(fmt.Sprintf("invalid use of LSym - NewFileInfo with Extra of type %T", *s.Extra))
}
f := new(FileInfo)
s.Extra = new(interface{})
*s.Extra = f
return f
}
/ File returns the *FileInfo associated with s, or else nil.
func (s *LSym) File() *FileInfo {
if s.Extra == nil {
return nil
}
f, _ := (*s.Extra).(*FileInfo)
return f
}
type InlMark struct {
/ When unwinding from an instruction in an inlined body, mark
/ where we should unwind to.
/ id records the global inlining id of the inlined body.
/ p records the location of an instruction in the parent (inliner) frame.
p *Prog
id int32
}
/ Mark p as the instruction to set as the pc when
/ "unwinding" the inlining global frame id. Usually it should be
/ instruction with a file:line at the callsite, and occur
/ just before the body of the inlined function.
func (fi *FuncInfo) AddInlMark(p *Prog, id int32) {
fi.InlMarks = append(fi.InlMarks, InlMark{p: p, id: id})
}
/ AddSpill appends a spill record to the list for FuncInfo fi
func (fi *FuncInfo) AddSpill(s RegSpill) {
fi.spills = append(fi.spills, s)
}
/ Record the type symbol for an auto variable so that the linker
/ an emit DWARF type information for the type.
func (fi *FuncInfo) RecordAutoType(gotype *LSym) {
if fi.Autot == nil {
fi.Autot = make(map[*LSym]struct{})
}
fi.Autot[gotype] = struct{}{}
}
/go:generate stringer -type ABI
/ ABI is the calling convention of a text symbol.
type ABI uint8
const (
/ ABI0 is the stable stack-based ABI. It's important that the
/ value of this is "0": we can't distinguish between
/ references to data and ABI0 text symbols in assembly code,
/ and hence this doesn't distinguish between symbols without
/ an ABI and text symbols with ABI0.
ABI0 ABI = iota
/ ABIInternal is the internal ABI that may change between Go
/ versions. All Go functions use the internal ABI and the
/ compiler generates wrappers for calls to and from other
/ ABIs.
ABIInternal
ABICount
)
/ ParseABI converts from a string representation in 'abistr' to the
/ corresponding ABI value. Second return value is TRUE if the
/ abi string is recognized, FALSE otherwise.
func ParseABI(abistr string) (ABI, bool) {
switch abistr {
default:
return ABI0, false
case "ABI0":
return ABI0, true
case "ABIInternal":
return ABIInternal, true
}
}
/ ABISet is a bit set of ABI values.
type ABISet uint8
const (
/ ABISetCallable is the set of all ABIs any function could
/ potentially be called using.
ABISetCallable ABISet = (1 << ABI0) | (1 << ABIInternal)
)
/ Ensure ABISet is big enough to hold all ABIs.
var _ ABISet = 1 << (ABICount - 1)
func ABISetOf(abi ABI) ABISet {
return 1 << abi
}
func (a *ABISet) Set(abi ABI, value bool) {
if value {
*a |= 1 << abi
} else {
*a &^= 1 << abi
}
}
func (a *ABISet) Get(abi ABI) bool {
return (*a>>abi)&1 != 0
}
func (a ABISet) String() string {
s := "{"
for i := ABI(0); a != 0; i++ {
if a&(1<<i) != 0 {
if s != "{" {
s += ","
}
s += i.String()
a &^= 1 << i
}
}
return s + "}"
}
/ Attribute is a set of symbol attributes.
type Attribute uint32
const (
AttrDuplicateOK Attribute = 1 << iota
AttrCFunc
AttrNoSplit
AttrLeaf
AttrWrapper
AttrNeedCtxt
AttrNoFrame
AttrOnList
AttrStatic
/ MakeTypelink means that the type should have an entry in the typelink table.
AttrMakeTypelink
/ ReflectMethod means the function may call reflect.Type.Method or
/ reflect.Type.MethodByName. Matching is imprecise (as reflect.Type
/ can be used through a custom interface), so ReflectMethod may be
/ set in some cases when the reflect package is not called.
/
/ Used by the linker to determine what methods can be pruned.
AttrReflectMethod
/ Local means make the symbol local even when compiling Go code to reference Go
/ symbols in other shared libraries, as in this mode symbols are global by
/ default. "local" here means in the sense of the dynamic linker, i.e. not
/ visible outside of the module (shared library or executable) that contains its
/ definition. (When not compiling to support Go shared libraries, all symbols are
/ local in this sense unless there is a cgo_export_* directive).
AttrLocal
/ For function symbols; indicates that the specified function was the
/ target of an inline during compilation
AttrWasInlined
/ Indexed indicates this symbol has been assigned with an index (when using the
/ new object file format).
AttrIndexed
/ Only applied on type descriptor symbols, UsedInIface indicates this type is
/ converted to an interface.
/
/ Used by the linker to determine what methods can be pruned.
AttrUsedInIface
/ ContentAddressable indicates this is a content-addressable symbol.
AttrContentAddressable
/ ABI wrapper is set for compiler-generated text symbols that
/ convert between ABI0 and ABIInternal calling conventions.
AttrABIWrapper
/ IsPcdata indicates this is a pcdata symbol.
AttrPcdata
/ attrABIBase is the value at which the ABI is encoded in
/ Attribute. This must be last; all bits after this are
/ assumed to be an ABI value.
/
/ MUST BE LAST since all bits above this comprise the ABI.
attrABIBase
)
func (a *Attribute) load() Attribute { return Attribute(atomic.LoadUint32((*uint32)(a))) }
func (a *Attribute) DuplicateOK() bool { return a.load()&AttrDuplicateOK != 0 }
func (a *Attribute) MakeTypelink() bool { return a.load()&AttrMakeTypelink != 0 }
func (a *Attribute) CFunc() bool { return a.load()&AttrCFunc != 0 }
func (a *Attribute) NoSplit() bool { return a.load()&AttrNoSplit != 0 }
func (a *Attribute) Leaf() bool { return a.load()&AttrLeaf != 0 }
func (a *Attribute) OnList() bool { return a.load()&AttrOnList != 0 }
func (a *Attribute) ReflectMethod() bool { return a.load()&AttrReflectMethod != 0 }
func (a *Attribute) Local() bool { return a.load()&AttrLocal != 0 }
func (a *Attribute) Wrapper() bool { return a.load()&AttrWrapper != 0 }
func (a *Attribute) NeedCtxt() bool { return a.load()&AttrNeedCtxt != 0 }
func (a *Attribute) NoFrame() bool { return a.load()&AttrNoFrame != 0 }
func (a *Attribute) Static() bool { return a.load()&AttrStatic != 0 }
func (a *Attribute) WasInlined() bool { return a.load()&AttrWasInlined != 0 }
func (a *Attribute) Indexed() bool { return a.load()&AttrIndexed != 0 }
func (a *Attribute) UsedInIface() bool { return a.load()&AttrUsedInIface != 0 }
func (a *Attribute) ContentAddressable() bool { return a.load()&AttrContentAddressable != 0 }
func (a *Attribute) ABIWrapper() bool { return a.load()&AttrABIWrapper != 0 }
func (a *Attribute) IsPcdata() bool { return a.load()&AttrPcdata != 0 }
func (a *Attribute) Set(flag Attribute, value bool) {
for {
v0 := a.load()
v := v0
if value {
v |= flag
} else {
v &^= flag
}
if atomic.CompareAndSwapUint32((*uint32)(a), uint32(v0), uint32(v)) {
break
}
}
}
func (a *Attribute) ABI() ABI { return ABI(a.load() / attrABIBase) }
func (a *Attribute) SetABI(abi ABI) {
const mask = 1 / Only one ABI bit for now.
for {
v0 := a.load()
v := (v0 &^ (mask * attrABIBase)) | Attribute(abi)*attrABIBase
if atomic.CompareAndSwapUint32((*uint32)(a), uint32(v0), uint32(v)) {
break
}
}
}
var textAttrStrings = [...]struct {
bit Attribute
s string
}{
{bit: AttrDuplicateOK, s: "DUPOK"},
{bit: AttrMakeTypelink, s: ""},
{bit: AttrCFunc, s: "CFUNC"},
{bit: AttrNoSplit, s: "NOSPLIT"},
{bit: AttrLeaf, s: "LEAF"},
{bit: AttrOnList, s: ""},
{bit: AttrReflectMethod, s: "REFLECTMETHOD"},
{bit: AttrLocal, s: "LOCAL"},
{bit: AttrWrapper, s: "WRAPPER"},
{bit: AttrNeedCtxt, s: "NEEDCTXT"},
{bit: AttrNoFrame, s: "NOFRAME"},
{bit: AttrStatic, s: "STATIC"},
{bit: AttrWasInlined, s: ""},
{bit: AttrIndexed, s: ""},
{bit: AttrContentAddressable, s: ""},
{bit: AttrABIWrapper, s: "ABIWRAPPER"},
}
/ String formats a for printing in as part of a TEXT prog.
func (a Attribute) String() string {
var s string
for _, x := range textAttrStrings {
if a&x.bit != 0 {
if x.s != "" {
s += x.s + "|"
}
a &^= x.bit
}
}
switch a.ABI() {
case ABI0:
case ABIInternal:
s += "ABIInternal|"
a.SetABI(0) / Clear ABI so we don't print below.
}
if a != 0 {
s += fmt.Sprintf("UnknownAttribute(%d)|", a)
}
/ Chop off trailing |, if present.
if len(s) > 0 {
s = s[:len(s)-1]
}
return s
}
/ TextAttrString formats the symbol attributes for printing in as part of a TEXT prog.
func (s *LSym) TextAttrString() string {
attr := s.Attribute.String()
if s.Func().FuncFlag&objabi.FuncFlag_TOPFRAME != 0 {
if attr != "" {
attr += "|"
}
attr += "TOPFRAME"
}
return attr
}
func (s *LSym) String() string {
return s.Name
}
/ The compiler needs *LSym to be assignable to cmd/compile/internal/ssa.Sym.
func (*LSym) CanBeAnSSASym() {}
func (*LSym) CanBeAnSSAAux() {}
type Pcln struct {
/ Aux symbols for pcln
Pcsp *LSym
Pcfile *LSym
Pcline *LSym
Pcinline *LSym
Pcdata []*LSym
Funcdata []*LSym
UsedFiles map[goobj.CUFileIndex]struct{} / file indices used while generating pcfile
InlTree InlTree / per-function inlining tree extracted from the global tree
}
type Reloc struct {
Off int32
Siz uint8
Type objabi.RelocType
Add int64
Sym *LSym
}
type Auto struct {
Asym *LSym
Aoffset int32
Name AddrName
Gotype *LSym
}
/ RegSpill provides spill/fill information for a register-resident argument
/ to a function. These need spilling/filling in the safepoint/stackgrowth case.
/ At the time of fill/spill, the offset must be adjusted by the architecture-dependent
/ adjustment to hardware SP that occurs in a call instruction. E.g., for AMD64,
/ at Offset+8 because the return address was pushed.
type RegSpill struct {
Addr Addr
Reg int16
Spill, Unspill As
}
/ Link holds the context for writing object code from a compiler
/ to be linker input or for reading that input into the linker.
type Link struct {
Headtype objabi.HeadType
Arch *LinkArch
Debugasm int
Debugvlog bool
Debugpcln string
Flag_shared bool
Flag_dynlink bool
Flag_linkshared bool
Flag_optimize bool
Flag_locationlists bool
Flag_noRefName bool / do not include referenced symbol names in object file
Retpoline bool / emit use of retpoline stubs for indirect jmp/call
Flag_maymorestack string / If not "", call this function before stack checks
Bso *bufio.Writer
Pathname string
Pkgpath string / the current package's import path
hashmu sync.Mutex / protects hash, funchash
hash map[string]*LSym / name -> sym mapping
funchash map[string]*LSym / name -> sym mapping for ABIInternal syms
statichash map[string]*LSym / name -> sym mapping for static syms
PosTable src.PosTable
InlTree InlTree / global inlining tree used by gc/inl.go
DwFixups *DwarfFixupTable
Imports []goobj.ImportedPkg
DiagFunc func(string, ...interface{})
DiagFlush func()
DebugInfo func(fn *LSym, info *LSym, curfn interface{}) ([]dwarf.Scope, dwarf.InlCalls) / if non-nil, curfn is a *gc.Node
GenAbstractFunc func(fn *LSym)
Errors int
InParallel bool / parallel backend phase in effect
UseBASEntries bool / use Base Address Selection Entries in location lists and PC ranges
IsAsm bool / is the source assembly language, which may contain surprising idioms (e.g., call tables)
/ state for writing objects
Text []*LSym
Data []*LSym
/ Constant symbols (e.g. $i64.*) are data symbols created late
/ in the concurrent phase. To ensure a deterministic order, we
/ add them to a separate list, sort at the end, and append it
/ to Data.
constSyms []*LSym
/ pkgIdx maps package path to index. The index is used for
/ symbol reference in the object file.
pkgIdx map[string]int32
defs []*LSym / list of defined symbols in the current package
hashed64defs []*LSym / list of defined short (64-bit or less) hashed (content-addressable) symbols
hasheddefs []*LSym / list of defined hashed (content-addressable) symbols
nonpkgdefs []*LSym / list of defined non-package symbols
nonpkgrefs []*LSym / list of referenced non-package symbols
Fingerprint goobj.FingerprintType / fingerprint of symbol indices, to catch index mismatch
}
func (ctxt *Link) Diag(format string, args ...interface{}) {
ctxt.Errors++
ctxt.DiagFunc(format, args...)
}
func (ctxt *Link) Logf(format string, args ...interface{}) {
fmt.Fprintf(ctxt.Bso, format, args...)
ctxt.Bso.Flush()
}
/ SpillRegisterArgs emits the code to spill register args into whatever
/ locations the spill records specify.
func (fi *FuncInfo) SpillRegisterArgs(last *Prog, pa ProgAlloc) *Prog {
/ Spill register args.
for _, ra := range fi.spills {
spill := Appendp(last, pa)
spill.As = ra.Spill
spill.From.Type = TYPE_REG
spill.From.Reg = ra.Reg
spill.To = ra.Addr
last = spill
}
return last
}
/ UnspillRegisterArgs emits the code to restore register args from whatever
/ locations the spill records specify.
func (fi *FuncInfo) UnspillRegisterArgs(last *Prog, pa ProgAlloc) *Prog {
/ Unspill any spilled register args
for _, ra := range fi.spills {
unspill := Appendp(last, pa)
unspill.As = ra.Unspill
unspill.From = ra.Addr
unspill.To.Type = TYPE_REG
unspill.To.Reg = ra.Reg
last = unspill
}
return last
}
/ LinkArch is the definition of a single architecture.
type LinkArch struct {
*sys.Arch
Init func(*Link)
ErrorCheck func(*Link, *LSym)
Preprocess func(*Link, *LSym, ProgAlloc)
Assemble func(*Link, *LSym, ProgAlloc)
Progedit func(*Link, *Prog, ProgAlloc)
UnaryDst map[As]bool / Instruction takes one operand, a destination.
DWARFRegisters map[int16]int16
}