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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 obj
"cmd/internal/dwarf"
"cmd/internal/objabi"
"internal/abi"
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// 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
Cherry Zhang
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// 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
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// 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.
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// 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]
// Encoding:
// type = TYPE_REGLIST
// 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)
// 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
NAME_NONE AddrName = iota
NAME_EXTERN
NAME_STATIC
NAME_AUTO
NAME_PARAM
Michael Hudson-Doyle
committed
// 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,
Robert Griesemer
committed
// 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}, same kinds of operands are saved in order
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, RISCV Rounding Mode)
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
// AddrPos indicates whether the operand 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.
func (p *Prog) From3Type() AddrType {
from3 := p.GetFrom3()
if from3 == nil {
}
// GetFrom3 returns second source operand (the first is Prog.From).
// The same kinds of operands are saved in order so GetFrom3 actually
// return the first source operand in p.RestArgs.
// In combination with Prog.From and Prog.To it makes common 3 operand
// case easier to use.
func (p *Prog) GetFrom3() *Addr {
for i := range p.RestArgs {
if p.RestArgs[i].Pos == Source {
return &p.RestArgs[i].Addr
}
// AddRestSource assigns []Args{{a, Source}} to p.RestArgs.
func (p *Prog) AddRestSource(a Addr) {
p.RestArgs = append(p.RestArgs, AddrPos{a, Source})
// AddRestSourceReg calls p.AddRestSource with a register Addr containing reg.
func (p *Prog) AddRestSourceReg(reg int16) {
p.AddRestSource(Addr{Type: TYPE_REG, Reg: reg})
// AddRestSourceConst calls p.AddRestSource with a const Addr containing off.
func (p *Prog) AddRestSourceConst(off int64) {
p.AddRestSource(Addr{Type: TYPE_CONST, Offset: off})
// AddRestDest assigns []Args{{a, Destination}} to p.RestArgs when the second destination
// operand does not fit into prog.RegTo2.
func (p *Prog) AddRestDest(a Addr) {
p.RestArgs = append(p.RestArgs, AddrPos{a, Destination})
}
// GetTo2 returns the second destination operand.
// The same kinds of operands are saved in order so GetTo2 actually
// return the first destination operand in Prog.RestArgs[]
func (p *Prog) GetTo2() *Addr {
for i := range p.RestArgs {
if p.RestArgs[i].Pos == Destination {
return &p.RestArgs[i].Addr
}
// AddRestSourceArgs assigns more than one source operands to p.RestArgs.
func (p *Prog) AddRestSourceArgs(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.
ACALL
ADUFFCOPY
ADUFFZERO
AEND
AFUNCDATA
AJMP
ANOP
Lynn Boger
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APCALIGN
APCALIGNMAX // currently x86, amd64 and arm64
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
ABaseLoong64
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.
Michael Hudson-Doyle
committed
// 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, *VarInfo, *FileInfo, or *TypeInfo, if present
Pkg string
PkgIdx int32
}
// A FuncInfo contains extra fields for STEXT symbols.
type FuncInfo struct {
Args int32
Locals int32
Align int32
FuncID abi.FuncID
FuncFlag abi.FuncFlag
StartLine int32
Text *Prog
Autot map[*LSym]struct{}
Pcln Pcln
InlMarks []InlMark
spills []RegSpill
dwarfInfoSym *LSym
dwarfLocSym *LSym
dwarfRangesSym *LSym
dwarfAbsFnSym *LSym
dwarfDebugLinesSym *LSym
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committed
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
FuncInfoSym *LSym
WasmImport *WasmImport
sehUnwindInfoSym *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
}
type VarInfo struct {
dwarfInfoSym *LSym
}
// NewVarInfo allocates and returns a VarInfo for LSym.
func (s *LSym) NewVarInfo() *VarInfo {
if s.Extra != nil {
panic(fmt.Sprintf("invalid use of LSym - NewVarInfo with Extra of type %T", *s.Extra))
}
f := new(VarInfo)
s.Extra = new(interface{})
*s.Extra = f
return f
}
// VarInfo returns the *VarInfo associated with s, or else nil.
func (s *LSym) VarInfo() *VarInfo {
if s.Extra == nil {
return nil
}
f, _ := (*s.Extra).(*VarInfo)
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
}
// A TypeInfo contains information for a symbol
// that contains a runtime._type.
type TypeInfo struct {
Type interface{} // a *cmd/compile/internal/types.Type
}
func (s *LSym) NewTypeInfo() *TypeInfo {
if s.Extra != nil {
panic(fmt.Sprintf("invalid use of LSym - NewTypeInfo with Extra of type %T", *s.Extra))
}
t := new(TypeInfo)
s.Extra = new(interface{})
*s.Extra = t
return t
}
// WasmImport represents a WebAssembly (WASM) imported function with
// parameters and results translated into WASM types based on the Go function
// declaration.
type WasmImport struct {
// Module holds the WASM module name specified by the //go:wasmimport
// directive.
Module string
// Name holds the WASM imported function name specified by the
// //go:wasmimport directive.
Name string
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WasmFuncType // type of the imported function
// aux symbol to pass metadata to the linker, serialization of
// the fields above.
AuxSym *LSym
}
func (wi *WasmImport) CreateAuxSym() {
var b bytes.Buffer
wi.Write(&b)
p := b.Bytes()
wi.AuxSym = &LSym{
Type: objabi.SDATA, // doesn't really matter
P: append([]byte(nil), p...),
Size: int64(len(p)),
}
}
func (wi *WasmImport) Write(w *bytes.Buffer) {
var b [8]byte
writeUint32 := func(x uint32) {
binary.LittleEndian.PutUint32(b[:], x)
w.Write(b[:4])
}
writeString := func(s string) {
writeUint32(uint32(len(s)))
w.WriteString(s)
}
writeString(wi.Module)
writeString(wi.Name)
wi.WasmFuncType.Write(w)
}
func (wi *WasmImport) Read(b []byte) {
readUint32 := func() uint32 {
x := binary.LittleEndian.Uint32(b)
b = b[4:]
return x
}
readString := func() string {
n := readUint32()
s := string(b[:n])
b = b[n:]
return s
}
wi.Module = readString()
wi.Name = readString()
wi.WasmFuncType.Read(b)
}
// WasmFuncType represents a WebAssembly (WASM) function type with
// parameters and results translated into WASM types based on the Go function
// declaration.
type WasmFuncType struct {
// Params holds the imported function parameter fields.
Params []WasmField
// Results holds the imported function result fields.
Results []WasmField
}
func (ft *WasmFuncType) Write(w *bytes.Buffer) {
var b [8]byte
writeByte := func(x byte) {
}
writeUint32 := func(x uint32) {
binary.LittleEndian.PutUint32(b[:], x)
}
writeInt64 := func(x int64) {
binary.LittleEndian.PutUint64(b[:], uint64(x))
writeUint32(uint32(len(ft.Params)))
for _, f := range ft.Params {
writeByte(byte(f.Type))
writeInt64(f.Offset)
}
writeUint32(uint32(len(ft.Results)))
for _, f := range ft.Results {
writeByte(byte(f.Type))
writeInt64(f.Offset)
}
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func (ft *WasmFuncType) Read(b []byte) {
readByte := func() byte {
x := b[0]
b = b[1:]
return x
}
readUint32 := func() uint32 {
x := binary.LittleEndian.Uint32(b)
b = b[4:]
return x
}
readInt64 := func() int64 {
x := binary.LittleEndian.Uint64(b)
b = b[8:]
return int64(x)
}
ft.Params = make([]WasmField, readUint32())
for i := range ft.Params {
ft.Params[i].Type = WasmFieldType(readByte())
ft.Params[i].Offset = int64(readInt64())
}
ft.Results = make([]WasmField, readUint32())
for i := range ft.Results {
ft.Results[i].Type = WasmFieldType(readByte())
ft.Results[i].Offset = int64(readInt64())
}
}
type WasmField struct {
Type WasmFieldType
// Offset holds the frame-pointer-relative locations for Go's stack-based
// ABI. This is used by the src/cmd/internal/wasm package to map WASM
// import parameters to the Go stack in a wrapper function.
Offset int64
}
type WasmFieldType byte
const (
WasmI32 WasmFieldType = iota
WasmI64
WasmF32
WasmF64
WasmPtr
)
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
}
}
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// 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
// MakeTypelink means that the type should have an entry in the typelink table.
// 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.
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// 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).
// 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
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// 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
// PkgInit indicates this is a compiler-generated package init func.
AttrPkgInit
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// Linkname indicates this is a go:linkname'd symbol.
AttrLinkname
// 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) IsPkgInit() bool { return a.load()&AttrPkgInit != 0 }
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func (a *Attribute) IsLinkname() bool { return a.load()&AttrLinkname != 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"},
{bit: AttrPkgInit, s: "PKGINIT"},
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{bit: AttrLinkname, s: "LINKNAME"},
// String formats a for printing in as part of a TEXT prog.
func (a Attribute) String() string {