obj

package
v1.20.3 Latest Latest
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 Go to latest Published: Dec 23, 2023 License: BSD-3-Clause Imports: 23 Imported by: 0

Documentation

Index

Constants

View Source 
const (
	LINE_BASE   = -4
	LINE_RANGE  = 10
	PC_RANGE    = (255 - OPCODE_BASE) / LINE_RANGE
	OPCODE_BASE = 11
)

Generate a sequence of opcodes that is as short as possible. See section 6.2.5

View Source 
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.
)

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.

View Source 
const (
	// Don't profile the marked routine.
	//
	// Deprecated: Not implemented, do not use.
	NOPROF = 1

	// It is ok for the linker to get multiple of these symbols. It will
	// pick one of the duplicates to use.
	DUPOK = 2

	// Don't insert stack check preamble.
	NOSPLIT = 4

	// Put this data in a read-only section.
	RODATA = 8

	// This data contains no pointers.
	NOPTR = 16

	// This is a wrapper function and should not count as
	// disabling 'recover' or appear in tracebacks by default.
	WRAPPER = 32

	// This function uses its incoming context register.
	NEEDCTXT = 64

	// When passed to objw.Global, causes Local to be set to true on the LSym it creates.
	LOCAL = 128

	// Allocate a word of thread local storage and store the offset from the
	// thread local base to the thread local storage in this variable.
	TLSBSS = 256

	// Do not insert instructions to allocate a stack frame for this function.
	// Only valid on functions that declare a frame size of 0.
	// TODO(mwhudson): only implemented for ppc64x at present.
	NOFRAME = 512

	// Function can call reflect.Type.Method or reflect.Type.MethodByName.
	REFLECTMETHOD = 1024

	// Function is the outermost frame of the call stack. Call stack unwinders
	// should stop at this function.
	TOPFRAME = 2048

	// Function is an ABI wrapper.
	ABIWRAPPER = 4096
)
View Source 
const (
	C_SCOND     = (1 << 4) - 1
	C_SBIT      = 1 << 4
	C_PBIT      = 1 << 5
	C_WBIT      = 1 << 6
	C_FBIT      = 1 << 7
	C_UBIT      = 1 << 7
	C_SCOND_XOR = 14
)

ARM scond byte

View Source 
const (
	// Because of masking operations in the encodings, each register
	// space should start at 0 modulo some power of 2.
	RBase386     = 1 * 1024
	RBaseAMD64   = 2 * 1024
	RBaseARM     = 3 * 1024
	RBasePPC64   = 4 * 1024  // range [4k, 8k)
	RBaseARM64   = 8 * 1024  // range [8k, 13k)
	RBaseMIPS    = 13 * 1024 // range [13k, 14k)
	RBaseS390X   = 14 * 1024 // range [14k, 15k)
	RBaseRISCV   = 15 * 1024 // range [15k, 16k)
	RBaseWasm    = 16 * 1024
	RBaseLOONG64 = 17 * 1024
)
View Source 
const (
	RegListARMLo = 0
	RegListARMHi = 1 << 16

	// arm64 uses the 60th bit to differentiate from other archs
	RegListARM64Lo = 1 << 60
	RegListARM64Hi = 1<<61 - 1

	// x86 uses the 61th bit to differentiate from other archs
	RegListX86Lo = 1 << 61
	RegListX86Hi = 1<<62 - 1
)

Each architecture is allotted a distinct subspace: [Lo, Hi) for declaring its arch-specific register list numbers.

View Source 
const (
	LOG = 5
)
View Source 
const REG_NONE = 0
View Source 
const StaticNamePref = ".stmp_"

StaticNamePref is the prefix the front end applies to static temporary variables. When turned into LSyms, these can be tagged as static so as to avoid inserting them into the linker's name lookup tables.

View Source 
const UnlinkablePkg = "<unlinkable>" // invalid package path, used when compiled without -p flag

Variables

View Source 
var Anames = []string{
	"XXX",
	"CALL",
	"DUFFCOPY",
	"DUFFZERO",
	"END",
	"FUNCDATA",
	"JMP",
	"NOP",
	"PCALIGN",
	"PCDATA",
	"RET",
	"GETCALLERPC",
	"TEXT",
	"UNDEF",
}

Functions

func Bool2int 

func Bool2int(b bool) int

func CConv 

func CConv(s uint8) string

CConv formats opcode suffix bits (Prog.Scond).

func CConvARM 

func CConvARM(s uint8) string

CConvARM formats ARM opcode suffix bits (mostly condition codes).

func Dconv 

func Dconv(p *Prog, a *Addr) string

Dconv accepts an argument 'a' within a prog 'p' and returns a string with a formatted version of the argument.

func DconvWithABIDetail 

func DconvWithABIDetail(p *Prog, a *Addr) string

DconvWithABIDetail accepts an argument 'a' within a prog 'p' and returns a string with a formatted version of the argument, in which text symbols are rendered with explicit ABI selectors.

func Flushplist 

func Flushplist(ctxt *Link, plist *Plist, newprog ProgAlloc, myimportpath string)

func MarkUnsafePoints 

func MarkUnsafePoints(ctxt *Link, p0 *Prog, newprog ProgAlloc, isUnsafePoint, isRestartable func(*Prog) bool)

MarkUnsafePoints inserts PCDATAs to mark nonpreemptible and restartable instruction sequences, based on isUnsafePoint and isRestartable predicate. p0 is the start of the instruction stream. isUnsafePoint(p) returns true if p is not safe for async preemption. isRestartable(p) returns true if we can restart at the start of p (this Prog) upon async preemption. (Currently multi-Prog restartable sequence is not supported.) isRestartable can be nil. In this case it is treated as always returning false. If isUnsafePoint(p) and isRestartable(p) are both true, it is treated as an unsafe point.

func Nopout 

func Nopout(p *Prog)

func RLconv 

func RLconv(list int64) string

func Rconv 

func Rconv(reg int) string

func RegisterOpSuffix 

func RegisterOpSuffix(arch string, cconv func(uint8) string)

RegisterOpSuffix assigns cconv function for formatting opcode suffixes when compiling for GOARCH=arch.

cconv is never called with 0 argument.

func RegisterOpcode 

func RegisterOpcode(lo As, Anames []string)

RegisterOpcode binds a list of instruction names to a given instruction number range.

func RegisterRegister 

func RegisterRegister(lo, hi int, Rconv func(int) string)

RegisterRegister binds a pretty-printer (Rconv) for register numbers to a given register number range. Lo is inclusive, hi exclusive (valid registers are lo through hi-1).

func RegisterRegisterList 

func RegisterRegisterList(lo, hi int64, rlconv func(int64) string)

RegisterRegisterList binds a pretty-printer (RLconv) for register list numbers to a given register list number range. Lo is inclusive, hi exclusive (valid register list are lo through hi-1).

func RegisterSpecialOperands added in v1.19.1 

func RegisterSpecialOperands(lo, hi int64, rlconv func(int64) string)

RegisterSpecialOperands binds a pretty-printer (SPCconv) for special operand numbers to a given special operand number range. Lo is inclusive, hi is exclusive (valid special operands are lo through hi-1).

func SPCconv added in v1.19.1 

func SPCconv(spc int64) string

SPCconv returns the string representation of the special operand spc.

func WriteDconv 

func WriteDconv(w io.Writer, p *Prog, a *Addr)

WriteDconv accepts an argument 'a' within a prog 'p' and writes a formatted version of the arg to the writer.

func WriteObjFile 

func WriteObjFile(ctxt *Link, b *bio.Writer)

Entry point of writing new object file.

Types

type ABI 

type ABI uint8

ABI is the calling convention of a text symbol. 

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
)

func ParseABI 

func ParseABI(abistr string) (ABI, bool)

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 (ABI) String 

func (i ABI) String() string

type ABISet 

type ABISet uint8

ABISet is a bit set of ABI values. 

const (
	// ABISetCallable is the set of all ABIs any function could
	// potentially be called using.
	ABISetCallable ABISet = (1 << ABI0) | (1 << ABIInternal)
)

func ABISetOf 

func ABISetOf(abi ABI) ABISet

func (*ABISet) Get 

func (a *ABISet) Get(abi ABI) bool

func (*ABISet) Set 

func (a *ABISet) Set(abi ABI, value bool)

func (ABISet) String 

func (a ABISet) String() string

type Addr 

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{}
}

func (*Addr) SetConst 

func (a *Addr) SetConst(v int64)

func (*Addr) SetTarget 

func (a *Addr) SetTarget(t *Prog)

func (*Addr) Target 

func (a *Addr) Target() *Prog

func (*Addr) WriteNameTo 

func (a *Addr) WriteNameTo(w io.Writer)

type AddrName 

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
)

type AddrPos 

type AddrPos struct {
	Addr
	Pos OperandPos
}

AddrPos indicates whether the operand is the source or the destination.

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 (AddrType) String 

func (i AddrType) String() string

type As 

type As int16

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. 

const (
	AXXX As = iota
	ACALL
	ADUFFCOPY
	ADUFFZERO
	AEND
	AFUNCDATA
	AJMP
	ANOP
	APCALIGN
	APCDATA
	ARET
	AGETCALLERPC
	ATEXT
	AUNDEF
	A_ARCHSPECIFIC
)

These are the portable opcodes.

func (As) String 

func (a As) String() string

type Attribute 

type Attribute uint32

Attribute is a set of symbol attributes. 

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
)

func (*Attribute) ABI 

func (a *Attribute) ABI() ABI

func (*Attribute) ABIWrapper 

func (a *Attribute) ABIWrapper() bool

func (*Attribute) CFunc 

func (a *Attribute) CFunc() bool

func (*Attribute) ContentAddressable 

func (a *Attribute) ContentAddressable() bool

func (*Attribute) DuplicateOK 

func (a *Attribute) DuplicateOK() bool

func (*Attribute) Indexed 

func (a *Attribute) Indexed() bool

func (*Attribute) IsPcdata 

func (a *Attribute) IsPcdata() bool

func (*Attribute) Leaf 

func (a *Attribute) Leaf() bool

func (*Attribute) Local 

func (a *Attribute) Local() bool
func (a *Attribute) MakeTypelink() bool

func (*Attribute) NeedCtxt 

func (a *Attribute) NeedCtxt() bool

func (*Attribute) NoFrame 

func (a *Attribute) NoFrame() bool

func (*Attribute) NoSplit 

func (a *Attribute) NoSplit() bool

func (*Attribute) OnList 

func (a *Attribute) OnList() bool

func (*Attribute) ReflectMethod 

func (a *Attribute) ReflectMethod() bool

func (*Attribute) Set 

func (a *Attribute) Set(flag Attribute, value bool)

func (*Attribute) SetABI 

func (a *Attribute) SetABI(abi ABI)

func (*Attribute) Static 

func (a *Attribute) Static() bool

func (Attribute) String 

func (a Attribute) String() string

String formats a for printing in as part of a TEXT prog.

func (*Attribute) UsedInIface 

func (a *Attribute) UsedInIface() bool

func (*Attribute) WasInlined 

func (a *Attribute) WasInlined() bool

func (*Attribute) Wrapper 

func (a *Attribute) Wrapper() bool

type Auto 

type Auto struct {
	Asym    *LSym
	Aoffset int32
	Name    AddrName
	Gotype  *LSym
}

type BySymName 

type BySymName []*LSym

func (BySymName) Len 

func (s BySymName) Len() int

func (BySymName) Less 

func (s BySymName) Less(i, j int) bool

func (BySymName) Swap 

func (s BySymName) Swap(i, j int)

type DwarfFixupTable 

type DwarfFixupTable struct {
	// contains filtered or unexported fields
}

This table is designed to aid in the creation of references between DWARF subprogram DIEs.

In most cases when one DWARF DIE has to refer to another DWARF DIE, the target of the reference has an LSym, which makes it easy to use the existing relocation mechanism. For DWARF inlined routine DIEs, however, the subprogram DIE has to refer to a child parameter/variable DIE of the abstract subprogram. This child DIE doesn't have an LSym, and also of interest is the fact that when DWARF generation is happening for inlined function F within caller G, it's possible that DWARF generation hasn't happened yet for F, so there is no way to know the offset of a child DIE within F's abstract function. Making matters more complex, each inlined instance of F may refer to a subset of the original F's variables (depending on what happens with optimization, some vars may be eliminated).

The fixup table below helps overcome this hurdle. At the point where a parameter/variable reference is made (via a call to "ReferenceChildDIE"), a fixup record is generate that records the relocation that is targeting that child variable. At a later point when the abstract function DIE is emitted, there will be a call to "RegisterChildDIEOffsets", at which point the offsets needed to apply fixups are captured. Finally, once the parallel portion of the compilation is done, fixups can actually be applied during the "Finalize" method (this can't be done during the parallel portion of the compile due to the possibility of data races).

This table is also used to record the "precursor" function node for each function that is the target of an inline -- child DIE references have to be made with respect to the original pre-optimization version of the function (to allow for the fact that each inlined body may be optimized differently).

func NewDwarfFixupTable 

func NewDwarfFixupTable(ctxt *Link) *DwarfFixupTable

func (*DwarfFixupTable) AbsFuncDwarfSym 

func (ft *DwarfFixupTable) AbsFuncDwarfSym(fnsym *LSym) *LSym

return the LSym corresponding to the 'abstract subprogram' DWARF info entry for a function.

func (*DwarfFixupTable) Finalize 

func (ft *DwarfFixupTable) Finalize(myimportpath string, trace bool)

Called after all functions have been compiled; the main job of this function is to identify cases where there are outstanding fixups. This scenario crops up when we have references to variables of an inlined routine, but that routine is defined in some other package. This helper walks through and locate these fixups, then invokes a helper to create an abstract subprogram DIE for each one.

func (*DwarfFixupTable) GetPrecursorFunc 

func (ft *DwarfFixupTable) GetPrecursorFunc(s *LSym) interface{}

func (*DwarfFixupTable) ReferenceChildDIE 

func (ft *DwarfFixupTable) ReferenceChildDIE(s *LSym, ridx int, tgt *LSym, dclidx int, inlIndex int)

Make a note of a child DIE reference: relocation 'ridx' within symbol 's' is targeting child 'c' of DIE with symbol 'tgt'.

func (*DwarfFixupTable) RegisterChildDIEOffsets 

func (ft *DwarfFixupTable) RegisterChildDIEOffsets(s *LSym, vars []*dwarf.Var, coffsets []int32)

Called once DWARF generation is complete for a given abstract function, whose children might have been referenced via a call above. Stores the offsets for any child DIEs (vars, params) so that they can be consumed later in on DwarfFixupTable.Finalize, which applies any outstanding fixups.

func (*DwarfFixupTable) SetPrecursorFunc 

func (ft *DwarfFixupTable) SetPrecursorFunc(s *LSym, fn interface{})

type FileInfo 

type FileInfo struct {
	Name string // name of file to read into object file
	Size int64  // length of file
}

A FileInfo contains extra fields for SDATA symbols backed by files. (If LSym.Extra is a *FileInfo, LSym.P == nil.)

type FuncInfo 

type FuncInfo struct {
	Args      int32
	Locals    int32
	Align     int32
	FuncID    objabi.FuncID
	FuncFlag  objabi.FuncFlag
	StartLine int32
	Text      *Prog
	Autot     map[*LSym]struct{}
	Pcln      Pcln
	InlMarks  []InlMark

	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
	// contains filtered or unexported fields
}

A FuncInfo contains extra fields for STEXT symbols.

func (*FuncInfo) AddInlMark 

func (fi *FuncInfo) AddInlMark(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 (*FuncInfo) AddSpill 

func (fi *FuncInfo) AddSpill(s RegSpill)

AddSpill appends a spill record to the list for FuncInfo fi

func (*FuncInfo) RecordAutoType 

func (fi *FuncInfo) RecordAutoType(gotype *LSym)

Record the type symbol for an auto variable so that the linker an emit DWARF type information for the type.

func (*FuncInfo) SpillRegisterArgs 

func (fi *FuncInfo) SpillRegisterArgs(last *Prog, pa ProgAlloc) *Prog

SpillRegisterArgs emits the code to spill register args into whatever locations the spill records specify.

func (*FuncInfo) UnspillRegisterArgs 

func (fi *FuncInfo) UnspillRegisterArgs(last *Prog, pa ProgAlloc) *Prog

UnspillRegisterArgs emits the code to restore register args from whatever locations the spill records specify.

type InlMark 

type InlMark struct {
	// contains filtered or unexported fields
}

type InlTree 

type InlTree struct {
	// contains filtered or unexported fields
}

InlTree is a collection of inlined calls. The Parent field of an InlinedCall is the index of another InlinedCall in InlTree.

The compiler maintains a global inlining tree and adds a node to it every time a function is inlined. For example, suppose f() calls g() and g has two calls to h(), and that f, g, and h are inlineable: 

 1 func main() {
 2     f()
 3 }
 4 func f() {
 5     g()
 6 }
 7 func g() {
 8     h()
 9     h()
10 }
11 func h() {
12     println("H")
13 }

Assuming the global tree starts empty, inlining will produce the following tree: 

[]InlinedCall{
  {Parent: -1, Func: "f", Pos: <line 2>},
  {Parent:  0, Func: "g", Pos: <line 5>},
  {Parent:  1, Func: "h", Pos: <line 8>},
  {Parent:  1, Func: "h", Pos: <line 9>},
}

The nodes of h inlined into main will have inlining indexes 2 and 3.

Eventually, the compiler extracts a per-function inlining tree from the global inlining tree (see pcln.go).

func (*InlTree) Add 

func (tree *InlTree) Add(parent int, pos src.XPos, func_ *LSym) int

Add adds a new call to the tree, returning its index.

func (*InlTree) CallPos 

func (tree *InlTree) CallPos(inlIndex int) src.XPos

func (*InlTree) InlinedFunction 

func (tree *InlTree) InlinedFunction(inlIndex int) *LSym

func (*InlTree) Parent 

func (tree *InlTree) Parent(inlIndex int) int

type InlinedCall 

type InlinedCall struct {
	Parent   int      // index of the parent in the InlTree or < 0 if outermost call
	Pos      src.XPos // position of the inlined call
	Func     *LSym    // function that was inlined
	ParentPC int32    // PC of instruction just before inlined body. Only valid in local trees.
}

InlinedCall is a node in an InlTree.

type JumpTable added in v1.19.1 

type JumpTable struct {
	Sym     *LSym
	Targets []*Prog
}

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 LSym 

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
}

An LSym is the sort of symbol that is written to an object file. It represents Go symbols in a flat pkg+"."+name namespace.

func (*LSym) CanBeAnSSAAux 

func (*LSym) CanBeAnSSAAux()

func (*LSym) CanBeAnSSASym 

func (*LSym) CanBeAnSSASym()

The compiler needs *LSym to be assignable to cmd/compile/github.com/go-asm/go/ssa.Sym.

func (*LSym) File 

func (s *LSym) File() *FileInfo

File returns the *FileInfo associated with s, or else nil.

func (*LSym) Func 

func (s *LSym) Func() *FuncInfo

Func returns the *FuncInfo associated with s, or else nil.

func (*LSym) Grow 

func (s *LSym) Grow(lsiz int64)

Grow increases the length of s.P to lsiz.

func (*LSym) GrowCap 

func (s *LSym) GrowCap(c int64)

GrowCap increases the capacity of s.P to c.

func (*LSym) Length 

func (s *LSym) Length(dwarfContext interface{}) int64

func (*LSym) NewFileInfo 

func (s *LSym) NewFileInfo() *FileInfo

NewFileInfo allocates and returns a FileInfo for LSym.

func (*LSym) NewFuncInfo 

func (s *LSym) NewFuncInfo() *FuncInfo

NewFuncInfo allocates and returns a FuncInfo for LSym.

func (*LSym) String 

func (s *LSym) String() string

func (*LSym) TextAttrString 

func (s *LSym) TextAttrString() string

TextAttrString formats the symbol attributes for printing in as part of a TEXT prog.

func (*LSym) WriteAddr 

func (s *LSym) WriteAddr(ctxt *Link, off int64, siz int, rsym *LSym, roff int64)

WriteAddr writes an address of size siz into s at offset off. rsym and roff specify the relocation for the address.

func (*LSym) WriteBytes 

func (s *LSym) WriteBytes(ctxt *Link, off int64, b []byte) int64

WriteBytes writes a slice of bytes into s at offset off.

func (*LSym) WriteCURelativeAddr 

func (s *LSym) WriteCURelativeAddr(ctxt *Link, off int64, rsym *LSym, roff int64)

WriteCURelativeAddr writes a pointer-sized address into s at offset off. rsym and roff specify the relocation for the address which will be resolved by the linker to an offset from the DW_AT_low_pc attribute of the DWARF Compile Unit of rsym.

func (*LSym) WriteFloat32 

func (s *LSym) WriteFloat32(ctxt *Link, off int64, f float32)

WriteFloat32 writes f into s at offset off.

func (*LSym) WriteFloat64 

func (s *LSym) WriteFloat64(ctxt *Link, off int64, f float64)

WriteFloat64 writes f into s at offset off.

func (*LSym) WriteInt 

func (s *LSym) WriteInt(ctxt *Link, off int64, siz int, i int64)

WriteInt writes an integer i of size siz into s at offset off.

func (*LSym) WriteOff 

func (s *LSym) WriteOff(ctxt *Link, off int64, rsym *LSym, roff int64)

WriteOff writes a 4 byte offset to rsym+roff into s at offset off. After linking the 4 bytes stored at s+off will be rsym+roff-(start of section that s is in).

func (*LSym) WriteString 

func (s *LSym) WriteString(ctxt *Link, off int64, siz int, str string)

WriteString writes a string of size siz into s at offset off.

func (*LSym) WriteWeakAddr 

func (s *LSym) WriteWeakAddr(ctxt *Link, off int64, siz int, rsym *LSym, roff int64)

WriteWeakAddr writes an address of size siz into s at offset off. rsym and roff specify the relocation for the address. This is a weak reference.

func (*LSym) WriteWeakOff 

func (s *LSym) WriteWeakOff(ctxt *Link, off int64, rsym *LSym, roff int64)

WriteWeakOff writes a weak 4 byte offset to rsym+roff into s at offset off. After linking the 4 bytes stored at s+off will be rsym+roff-(start of section that s is in). 

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

	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

	Fingerprint goobj.FingerprintType // fingerprint of symbol indices, to catch index mismatch
	// contains filtered or unexported fields
}

Link holds the context for writing object code from a compiler to be linker input or for reading that input into the linker.

func Linknew 

func Linknew(arch *LinkArch) *Link

func (*Link) AddImport 

func (ctxt *Link) AddImport(pkg string, fingerprint goobj.FingerprintType)

AddImport adds a package to the list of imported packages.

func (*Link) AllPos 

func (ctxt *Link) AllPos(xpos src.XPos, result []src.Pos) []src.Pos

AllPos returns a slice of the positions inlined at xpos, from innermost (index zero) to outermost. To avoid allocation the input slice is truncated, and used for the result, extended as necessary.

func (*Link) CanReuseProgs 

func (ctxt *Link) CanReuseProgs() bool

func (*Link) Diag 

func (ctxt *Link) Diag(format string, args ...interface{})

func (*Link) DwarfAbstractFunc 

func (ctxt *Link) DwarfAbstractFunc(curfn interface{}, s *LSym, myimportpath string)

func (*Link) DwarfGlobal 

func (ctxt *Link) DwarfGlobal(myimportpath, typename string, varSym *LSym)

DwarfGlobal creates a link symbol containing a DWARF entry for a global variable.

func (*Link) DwarfIntConst 

func (ctxt *Link) DwarfIntConst(myimportpath, name, typename string, val int64)

DwarfIntConst creates a link symbol for an integer constant with the given name, type and value.

func (*Link) EmitEntryLiveness 

func (ctxt *Link) EmitEntryLiveness(s *LSym, p *Prog, newprog ProgAlloc) *Prog

EmitEntryLiveness generates PCDATA Progs after p to switch to the liveness map active at the entry of function s. It returns the last Prog generated.

func (*Link) EmitEntryStackMap 

func (ctxt *Link) EmitEntryStackMap(s *LSym, p *Prog, newprog ProgAlloc) *Prog

Similar to EmitEntryLiveness, but just emit stack map.

func (*Link) EmitEntryUnsafePoint 

func (ctxt *Link) EmitEntryUnsafePoint(s *LSym, p *Prog, newprog ProgAlloc) *Prog

Similar to EmitEntryLiveness, but just emit unsafe point map.

func (*Link) EndUnsafePoint 

func (ctxt *Link) EndUnsafePoint(p *Prog, newprog ProgAlloc, oldval int64) *Prog

EndUnsafePoint generates PCDATA Progs after p to mark the end of an unsafe point, restoring the register map index to oldval. The unsafe point ends right after p. It returns the last Prog generated.

func (*Link) Float32Sym 

func (ctxt *Link) Float32Sym(f float32) *LSym

func (*Link) Float64Sym 

func (ctxt *Link) Float64Sym(f float64) *LSym

func (*Link) GCLocalsSym 

func (ctxt *Link) GCLocalsSym(data []byte) *LSym

GCLocalsSym generates a content-addressable sym containing data.

func (*Link) Globl 

func (ctxt *Link) Globl(s *LSym, size int64, flag int)

func (*Link) GloblPos added in v1.20.1 

func (ctxt *Link) GloblPos(s *LSym, size int64, flag int, pos src.XPos)

func (*Link) InitTextSym 

func (ctxt *Link) InitTextSym(s *LSym, flag int, start src.XPos)

func (*Link) InnermostPos 

func (ctxt *Link) InnermostPos(xpos src.XPos) src.Pos

InnermostPos returns the innermost position corresponding to xpos, that is, the code that is inlined and that inlines nothing else. In the example for InlTree above, the code for println within h would have an innermost position with line number 12, whether h was not inlined, inlined into g, g-then-f, or g-then-f-then-main. This corresponds to what someone debugging main, f, g, or h might expect to see while single-stepping.

func (*Link) Int64Sym 

func (ctxt *Link) Int64Sym(i int64) *LSym

func (*Link) Logf 

func (ctxt *Link) Logf(format string, args ...interface{})

func (*Link) Lookup 

func (ctxt *Link) Lookup(name string) *LSym

Lookup looks up the symbol with name name. If it does not exist, it creates it.

func (*Link) LookupABI 

func (ctxt *Link) LookupABI(name string, abi ABI) *LSym

LookupABI looks up a symbol with the given ABI. If it does not exist, it creates it.

func (*Link) LookupABIInit 

func (ctxt *Link) LookupABIInit(name string, abi ABI, init func(s *LSym)) *LSym

LookupABI looks up a symbol with the given ABI. If it does not exist, it creates it and passes it to init for one-time initialization.

func (*Link) LookupDerived 

func (ctxt *Link) LookupDerived(s *LSym, name string) *LSym

LookupDerived looks up or creates the symbol with name derived from symbol s. The resulting symbol will be static iff s is.

func (*Link) LookupInit 

func (ctxt *Link) LookupInit(name string, init func(s *LSym)) *LSym

LookupInit looks up the symbol with name name. If it does not exist, it creates it and passes it to init for one-time initialization.

func (*Link) LookupStatic 

func (ctxt *Link) LookupStatic(name string) *LSym

LookupStatic looks up the static symbol with name name. If it does not exist, it creates it.

func (*Link) NewProg 

func (ctxt *Link) NewProg() *Prog

func (*Link) NumberSyms 

func (ctxt *Link) NumberSyms()

Assign index to symbols. asm is set to true if this is called by the assembler (i.e. not the compiler), in which case all the symbols are non-package (for now).

func (*Link) OutermostPos 

func (ctxt *Link) OutermostPos(xpos src.XPos) src.Pos

OutermostPos returns the outermost position corresponding to xpos, which is where xpos was ultimately inlined to. In the example for InlTree, main() contains inlined AST nodes from h(), but the outermost position for those nodes is line 2.

func (*Link) StartUnsafePoint 

func (ctxt *Link) StartUnsafePoint(p *Prog, newprog ProgAlloc) *Prog

StartUnsafePoint generates PCDATA Progs after p to mark the beginning of an unsafe point. The unsafe point starts immediately after p. It returns the last Prog generated.

type LinkArch 

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
}

LinkArch is the definition of a single architecture.

type OperandPos 

type OperandPos int8
const (
	Source OperandPos = iota
	Destination
)

type PCIter 

type PCIter struct {
	PC      uint32
	NextPC  uint32
	PCScale uint32
	Value   int32

	Done bool
	// contains filtered or unexported fields
}

PCIter iterates over encoded pcdata tables.

func NewPCIter 

func NewPCIter(pcScale uint32) *PCIter

NewPCIter creates a PCIter with a scale factor for the PC step size.

func (*PCIter) Init 

func (it *PCIter) Init(p []byte)

init prepares it to iterate over p, and advances it to the first pc.

func (*PCIter) Next 

func (it *PCIter) Next()

Next advances it to the Next pc.

type Pcln 

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 Plist 

type Plist struct {
	Firstpc *Prog
	Curfn   interface{} // holds a *gc.Node, if non-nil
}

type Prog 

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
}

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.

func Appendp 

func Appendp(q *Prog, newprog ProgAlloc) *Prog

func (*Prog) AllPos 

func (p *Prog) AllPos(result []src.Pos) []src.Pos

func (*Prog) From3Type deprecated 

func (p *Prog) From3Type() AddrType

From3Type returns p.GetFrom3().Type, or TYPE_NONE when p.GetFrom3() returns nil.

Deprecated: for the same reasons as Prog.GetFrom3.

func (*Prog) GetFrom3 deprecated 

func (p *Prog) GetFrom3() *Addr

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 (*Prog) GetTo2 

func (p *Prog) GetTo2() *Addr

GetTo2 returns the second destination operand.

func (*Prog) InnermostFilename 

func (p *Prog) InnermostFilename() string

InnermostFilename returns a string containing the innermost (in inlining) filename at p's position

func (*Prog) InnermostLine 

func (p *Prog) InnermostLine(w io.Writer)

func (*Prog) InnermostLineNumber 

func (p *Prog) InnermostLineNumber() string

InnermostLineNumber returns a string containing the line number for the innermost inlined function (if any inlining) at p's position

func (*Prog) InnermostLineNumberHTML 

func (p *Prog) InnermostLineNumberHTML() string

InnermostLineNumberHTML returns a string containing the line number for the innermost inlined function (if any inlining) at p's position

func (*Prog) InnermostString 

func (p *Prog) InnermostString(w io.Writer)

func (*Prog) InstructionString 

func (p *Prog) InstructionString() string

InstructionString returns a string representation of the instruction without preceding program counter or file and line number.

func (*Prog) Line 

func (p *Prog) Line() string

Line returns a string containing the filename and line number for p

func (*Prog) SetFrom3 deprecated 

func (p *Prog) SetFrom3(a 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 (*Prog) SetFrom3Const deprecated 

func (p *Prog) SetFrom3Const(off int64)

SetFrom3Const calls p.SetFrom3 with a const Addr containing x.

Deprecated: for the same reasons as Prog.GetFrom3.

func (*Prog) SetFrom3Reg deprecated 

func (p *Prog) SetFrom3Reg(reg int16)

SetFrom3Reg calls p.SetFrom3 with a register Addr containing reg.

Deprecated: for the same reasons as Prog.GetFrom3.

func (*Prog) SetRestArgs 

func (p *Prog) SetRestArgs(args []Addr)

SetRestArgs assigns more than one source operands to p.RestArgs.

func (*Prog) SetTo2 

func (p *Prog) SetTo2(a Addr)

SetTo2 assigns []Args{{a, 1}} to p.RestArgs when the second destination operand does not fit into prog.RegTo2.

func (*Prog) String 

func (p *Prog) String() string

func (*Prog) WriteInstructionString 

func (p *Prog) WriteInstructionString(w io.Writer)

WriteInstructionString writes a string representation of the instruction without preceding program counter or file and line number.

type ProgAlloc 

type ProgAlloc func() *Prog

ProgAlloc is a function that allocates Progs. It is used to provide access to cached/bulk-allocated Progs to the assemblers.

type RegSpill 

type RegSpill struct {
	Addr           Addr
	Reg            int16
	Spill, Unspill As
}

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 Reloc 

type Reloc struct {
	Off  int32
	Siz  uint8
	Type objabi.RelocType
	Add  int64
	Sym  *LSym
}

func Addrel 

func Addrel(s *LSym) *Reloc

Source Files

View all Source files

Directories

Path Synopsis
Package arm64 implements an ARM64 assembler.
 Package arm64 implements an ARM64 assembler.
Package ppc64 implements a PPC64 assembler that assembles Go asm into the corresponding PPC64 instructions as defined by the Power ISA 3.0B.
 Package ppc64 implements a PPC64 assembler that assembles Go asm into the corresponding PPC64 instructions as defined by the Power ISA 3.0B.

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