Documentation ¶
Index ¶
- Constants
- Variables
- func AbsFile(dir, file, rewrites string) string
- func ApplyRewrites(file, rewrites string) (string, bool)
- func HeaderString() string
- func IsRuntimePackagePath(pkgpath string) bool
- func PathToPrefix(s string) string
- func WorkingDir() string
- type FuncFlag
- type FuncID
- type HeadType
- type RelocType
- type SymKind
Constants ¶
const ( A_AUTO = 1 + iota A_PARAM A_DELETED_AUTO )
Auto.name
const ( PCDATA_UnsafePoint = 0 PCDATA_StackMapIndex = 1 PCDATA_InlTreeIndex = 2 PCDATA_ArgLiveIndex = 3 FUNCDATA_ArgsPointerMaps = 0 FUNCDATA_LocalsPointerMaps = 1 FUNCDATA_StackObjects = 2 FUNCDATA_InlTree = 3 FUNCDATA_OpenCodedDeferInfo = 4 FUNCDATA_ArgInfo = 5 FUNCDATA_ArgLiveInfo = 6 FUNCDATA_WrapInfo = 7 // ArgsSizeUnknown is set in Func.argsize to mark all functions // whose argument size is unknown (C vararg functions, and // assembly code without an explicit specification). // This value is generated by the compiler, assembler, or linker. ArgsSizeUnknown = -0x80000000 )
const ( // PCDATA_UnsafePoint values. PCDATA_UnsafePointSafe = -1 // Safe for async preemption PCDATA_UnsafePointUnsafe = -2 // Unsafe for async preemption // PCDATA_Restart1(2) apply on a sequence of instructions, within // which if an async preemption happens, we should back off the PC // to the start of the sequence when resuming. // We need two so we can distinguish the start/end of the sequence // in case that two sequences are next to each other. PCDATA_Restart1 = -3 PCDATA_Restart2 = -4 // Like PCDATA_Restart1, but back to function entry if async preempted. PCDATA_RestartAtEntry = -5 )
Special PCDATA values.
const ( FuncFlag_TOPFRAME = 1 << iota FuncFlag_SPWRITE FuncFlag_ASM )
Note: This list must match the list in runtime/symtab.go.
const ( STACKSYSTEM = 0 StackSystem = STACKSYSTEM StackBig = 4096 StackSmall = 128 )
const ( KindBool = 1 + iota KindInt KindInt8 KindInt16 KindInt32 KindInt64 KindUint KindUint8 KindUint16 KindUint32 KindUint64 KindUintptr KindFloat32 KindFloat64 KindComplex64 KindComplex128 KindArray KindChan KindFunc KindInterface KindMap KindPtr KindSlice KindString KindStruct KindUnsafePointer KindDirectIface = 1 << 5 KindGCProg = 1 << 6 KindMask = (1 << 5) - 1 )
const ( ElfRelocOffset = 256 MachoRelocOffset = 2048 // reserve enough space for ELF relocations GlobalDictPrefix = ".dict" // prefix for names of global dictionaries )
Variables ¶
var StackGuard = 928*stackGuardMultiplier() + StackSystem
Initialize StackGuard and StackLimit according to target system.
var StackLimit = StackGuard - StackSystem - StackSmall
Functions ¶
func AbsFile ¶
AbsFile returns the absolute filename for file in the given directory, as rewritten by the rewrites argument. For unrewritten paths, AbsFile rewrites a leading $GOROOT prefix to the literal "$GOROOT". If the resulting path is the empty string, the result is "??".
The rewrites argument is a ;-separated list of rewrites. Each rewrite is of the form "prefix" or "prefix=>replace", where prefix must match a leading sequence of path elements and is either removed entirely or replaced by the replacement.
func ApplyRewrites ¶
ApplyRewrites returns the filename for file in the given directory, as rewritten by the rewrites argument.
The rewrites argument is a ;-separated list of rewrites. Each rewrite is of the form "prefix" or "prefix=>replace", where prefix must match a leading sequence of path elements and is either removed entirely or replaced by the replacement.
func HeaderString ¶
func HeaderString() string
HeaderString returns the toolchain configuration string written in Go object headers. This string ensures we don't attempt to import or link object files that are incompatible with each other. This string always starts with "go object ".
func IsRuntimePackagePath ¶
IsRuntimePackagePath examines 'pkgpath' and returns TRUE if it belongs to the collection of "runtime-related" packages, including "runtime" itself, "reflect", "syscall", and the "runtime/internal/*" packages. The compiler and/or assembler in some cases need to be aware of when they are building such a package, for example to enable features such as ABI selectors in assembly sources.
Keep in sync with cmd/dist/build.go:IsRuntimePackagePath.
func PathToPrefix ¶
PathToPrefix converts raw string to the prefix that will be used in the symbol table. All control characters, space, '%' and '"', as well as non-7-bit clean bytes turn into %xx. The period needs escaping only in the last segment of the path, and it makes for happier users if we escape that as little as possible.
func WorkingDir ¶
func WorkingDir() string
WorkingDir returns the current working directory (or "/???" if the directory cannot be identified), with "/" as separator.
Types ¶
type FuncFlag ¶
type FuncFlag uint8
A FuncFlag records bits about a function, passed to the runtime.
type FuncID ¶
type FuncID uint8
A FuncID identifies particular functions that need to be treated specially by the runtime. Note that in some situations involving plugins, there may be multiple copies of a particular special runtime function.
const ( FuncID_normal FuncID = iota // not a special function FuncID_abort FuncID_asmcgocall FuncID_asyncPreempt FuncID_cgocallback FuncID_debugCallV2 FuncID_gcBgMarkWorker FuncID_goexit FuncID_gogo FuncID_gopanic FuncID_handleAsyncEvent FuncID_mcall FuncID_morestack FuncID_mstart FuncID_panicwrap FuncID_rt0_go FuncID_runfinq FuncID_runtime_main FuncID_sigpanic FuncID_systemstack FuncID_systemstack_switch FuncID_wrapper // any autogenerated code (hash/eq algorithms, method wrappers, etc.) )
Note: this list must match the list in runtime/symtab.go.
type RelocType ¶
type RelocType int16
const ( R_ADDR RelocType = 1 + iota // R_ADDRPOWER relocates a pair of "D-form" instructions (instructions with 16-bit // immediates in the low half of the instruction word), usually addis followed by // another add or a load, inserting the "high adjusted" 16 bits of the address of // the referenced symbol into the immediate field of the first instruction and the // low 16 bits into that of the second instruction. R_ADDRPOWER // R_ADDRARM64 relocates an adrp, add pair to compute the address of the // referenced symbol. R_ADDRARM64 // R_ADDRMIPS (only used on mips/mips64) resolves to the low 16 bits of an external // address, by encoding it into the instruction. R_ADDRMIPS // R_ADDROFF resolves to a 32-bit offset from the beginning of the section // holding the data being relocated to the referenced symbol. R_ADDROFF R_SIZE R_CALL R_CALLARM R_CALLARM64 R_CALLIND R_CALLPOWER // R_CALLMIPS (only used on mips64) resolves to non-PC-relative target address // of a CALL (JAL) instruction, by encoding the address into the instruction. R_CALLMIPS R_CONST R_PCREL // R_TLS_LE, used on 386, amd64, and ARM, resolves to the offset of the // thread-local symbol from the thread local base and is used to implement the // "local exec" model for tls access (r.Sym is not set on intel platforms but is // set to a TLS symbol -- runtime.tlsg -- in the linker when externally linking). R_TLS_LE // R_TLS_IE, used 386, amd64, and ARM resolves to the PC-relative offset to a GOT // slot containing the offset from the thread-local symbol from the thread local // base and is used to implemented the "initial exec" model for tls access (r.Sym // is not set on intel platforms but is set to a TLS symbol -- runtime.tlsg -- in // the linker when externally linking). R_TLS_IE R_GOTOFF R_PLT0 R_PLT1 R_PLT2 R_USEFIELD // R_USETYPE resolves to an *rtype, but no relocation is created. The // linker uses this as a signal that the pointed-to type information // should be linked into the final binary, even if there are no other // direct references. (This is used for types reachable by reflection.) R_USETYPE // R_USEIFACE marks a type is converted to an interface in the function this // relocation is applied to. The target is a type descriptor. // This is a marker relocation (0-sized), for the linker's reachabililty // analysis. R_USEIFACE // R_USEIFACEMETHOD marks an interface method that is used in the function // this relocation is applied to. The target is an interface type descriptor. // The addend is the offset of the method in the type descriptor. // This is a marker relocation (0-sized), for the linker's reachabililty // analysis. R_USEIFACEMETHOD // Similar to R_USEIFACEMETHOD, except instead of indicating a type + // method offset with Sym+Add, Sym points to a symbol containing the name // of the method being called. See the description in // cmd/compile/internal/reflectdata/reflect.go:MarkUsedIfaceMethod for details. R_USEGENERICIFACEMETHOD // R_METHODOFF resolves to a 32-bit offset from the beginning of the section // holding the data being relocated to the referenced symbol. // It is a variant of R_ADDROFF used when linking from the uncommonType of a // *rtype, and may be set to zero by the linker if it determines the method // text is unreachable by the linked program. R_METHODOFF // R_KEEP tells the linker to keep the referred-to symbol in the final binary // if the symbol containing the R_KEEP relocation is in the final binary. R_KEEP R_POWER_TOC R_GOTPCREL // R_JMPMIPS (only used on mips64) resolves to non-PC-relative target address // of a JMP instruction, by encoding the address into the instruction. // The stack nosplit check ignores this since it is not a function call. R_JMPMIPS // R_DWARFSECREF resolves to the offset of the symbol from its section. // Target of relocation must be size 4 (in current implementation). R_DWARFSECREF // R_DWARFFILEREF resolves to an index into the DWARF .debug_line // file table for the specified file symbol. Must be applied to an // attribute of form DW_FORM_data4. R_DWARFFILEREF // Set a MOV[NZ] immediate field to bits [15:0] of the offset from the thread // local base to the thread local variable defined by the referenced (thread // local) symbol. Error if the offset does not fit into 16 bits. R_ARM64_TLS_LE // Relocates an ADRP; LD64 instruction sequence to load the offset between // the thread local base and the thread local variable defined by the // referenced (thread local) symbol from the GOT. R_ARM64_TLS_IE // R_ARM64_GOTPCREL relocates an adrp, ld64 pair to compute the address of the GOT // slot of the referenced symbol. R_ARM64_GOTPCREL // R_ARM64_GOT resolves a GOT-relative instruction sequence, usually an adrp // followed by another ld instruction. R_ARM64_GOT // R_ARM64_PCREL resolves a PC-relative addresses instruction sequence, usually an // adrp followed by another add instruction. R_ARM64_PCREL // R_ARM64_LDST8 sets a LD/ST immediate value to bits [11:0] of a local address. R_ARM64_LDST8 // R_ARM64_LDST16 sets a LD/ST immediate value to bits [11:1] of a local address. R_ARM64_LDST16 // R_ARM64_LDST32 sets a LD/ST immediate value to bits [11:2] of a local address. R_ARM64_LDST32 // R_ARM64_LDST64 sets a LD/ST immediate value to bits [11:3] of a local address. R_ARM64_LDST64 // R_ARM64_LDST128 sets a LD/ST immediate value to bits [11:4] of a local address. R_ARM64_LDST128 // R_POWER_TLS_LE is used to implement the "local exec" model for tls // access. It resolves to the offset of the thread-local symbol from the // thread pointer (R13) and is split against a pair of instructions to // support a 32 bit displacement. R_POWER_TLS_LE // R_POWER_TLS_IE is used to implement the "initial exec" model for tls access. It // relocates a D-form, DS-form instruction sequence like R_ADDRPOWER_DS. It // inserts to the offset of GOT slot for the thread-local symbol from the TOC (the // GOT slot is filled by the dynamic linker with the offset of the thread-local // symbol from the thread pointer (R13)). R_POWER_TLS_IE // R_POWER_TLS marks an X-form instruction such as "ADD R3,R13,R4" as completing // a sequence of GOT-relative relocations to compute a TLS address. This can be // used by the system linker to to rewrite the GOT-relative TLS relocation into a // simpler thread-pointer relative relocation. See table 3.26 and 3.28 in the // ppc64 elfv2 1.4 ABI on this transformation. Likewise, the second argument // (usually called RB in X-form instructions) is assumed to be R13. R_POWER_TLS // R_ADDRPOWER_DS is similar to R_ADDRPOWER above, but assumes the second // instruction is a "DS-form" instruction, which has an immediate field occupying // bits [15:2] of the instruction word. Bits [15:2] of the address of the // relocated symbol are inserted into this field; it is an error if the last two // bits of the address are not 0. R_ADDRPOWER_DS // R_ADDRPOWER_PCREL relocates a D-form, DS-form instruction sequence like // R_ADDRPOWER_DS but inserts the offset of the GOT slot for the referenced symbol // from the TOC rather than the symbol's address. R_ADDRPOWER_GOT // R_ADDRPOWER_PCREL relocates two D-form instructions like R_ADDRPOWER, but // inserts the displacement from the place being relocated to the address of the // relocated symbol instead of just its address. R_ADDRPOWER_PCREL // R_ADDRPOWER_TOCREL relocates two D-form instructions like R_ADDRPOWER, but // inserts the offset from the TOC to the address of the relocated symbol // rather than the symbol's address. R_ADDRPOWER_TOCREL // R_ADDRPOWER_TOCREL relocates a D-form, DS-form instruction sequence like // R_ADDRPOWER_DS but inserts the offset from the TOC to the address of the // relocated symbol rather than the symbol's address. R_ADDRPOWER_TOCREL_DS // R_RISCV_CALL relocates a J-type instruction with a 21 bit PC-relative // address. R_RISCV_CALL // R_RISCV_CALL_TRAMP is the same as R_RISCV_CALL but denotes the use of a // trampoline, which we may be able to avoid during relocation. These are // only used by the linker and are not emitted by the compiler or assembler. R_RISCV_CALL_TRAMP // R_RISCV_PCREL_ITYPE resolves a 32-bit PC-relative address using an // AUIPC + I-type instruction pair. R_RISCV_PCREL_ITYPE // R_RISCV_PCREL_STYPE resolves a 32-bit PC-relative address using an // AUIPC + S-type instruction pair. R_RISCV_PCREL_STYPE // R_RISCV_TLS_IE_ITYPE resolves a 32-bit TLS initial-exec TOC offset // address using an AUIPC + I-type instruction pair. R_RISCV_TLS_IE_ITYPE // R_RISCV_TLS_IE_STYPE resolves a 32-bit TLS initial-exec TOC offset // address using an AUIPC + S-type instruction pair. R_RISCV_TLS_IE_STYPE // R_PCRELDBL relocates s390x 2-byte aligned PC-relative addresses. // TODO(mundaym): remove once variants can be serialized - see issue 14218. R_PCRELDBL // R_ADDRMIPSU (only used on mips/mips64) resolves to the sign-adjusted "upper" 16 // bits (bit 16-31) of an external address, by encoding it into the instruction. R_ADDRMIPSU // R_ADDRMIPSTLS (only used on mips64) resolves to the low 16 bits of a TLS // address (offset from thread pointer), by encoding it into the instruction. R_ADDRMIPSTLS // R_ADDRCUOFF resolves to a pointer-sized offset from the start of the // symbol's DWARF compile unit. R_ADDRCUOFF // R_WASMIMPORT resolves to the index of the WebAssembly function import. R_WASMIMPORT // R_XCOFFREF (only used on aix/ppc64) prevents garbage collection by ld // of a symbol. This isn't a real relocation, it can be placed in anywhere // in a symbol and target any symbols. R_XCOFFREF // R_WEAK marks the relocation as a weak reference. // A weak relocation does not make the symbol it refers to reachable, // and is only honored by the linker if the symbol is in some other way // reachable. R_WEAK = -1 << 15 R_WEAKADDR = R_WEAK | R_ADDR R_WEAKADDROFF = R_WEAK | R_ADDROFF )
func (RelocType) IsDirectCall ¶
IsDirectCall reports whether r is a relocation for a direct call. A direct call is a CALL instruction that takes the target address as an immediate. The address is embedded into the instruction, possibly with limited width. An indirect call is a CALL instruction that takes the target address in register or memory.
func (RelocType) IsDirectCallOrJump ¶
IsDirectCallOrJump reports whether r is a relocation for a direct call or a direct jump.
func (RelocType) IsDirectJump ¶
IsDirectJump reports whether r is a relocation for a direct jump. A direct jump is a JMP instruction that takes the target address as an immediate. The address is embedded into the instruction, possibly with limited width. An indirect jump is a JMP instruction that takes the target address in register or memory.
type SymKind ¶
type SymKind uint8
A SymKind describes the kind of memory represented by a symbol.
const ( // An otherwise invalid zero value for the type Sxxx SymKind = iota // Executable instructions STEXT // Read only static data SRODATA // Static data that does not contain any pointers SNOPTRDATA // Static data SDATA // Statically data that is initially all 0s SBSS // Statically data that is initially all 0s and does not contain pointers SNOPTRBSS // Thread-local data that is initially all 0s STLSBSS // Debugging data SDWARFCUINFO SDWARFCONST SDWARFFCN SDWARFABSFCN SDWARFTYPE SDWARFVAR SDWARFRANGE SDWARFLOC SDWARFLINES // Coverage instrumentation counter for libfuzzer. SLIBFUZZER_EXTRA_COUNTER )
Defined SymKind values. These are used to index into cmd/link/internal/sym/AbiSymKindToSymKind
TODO(rsc): Give idiomatic Go names.