golang reloctype 代码
文件路径：/src/cmd/internal/objabi/reloctype.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 objabi
type RelocType int16
/go:generate stringer -type=RelocType
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
/ Platform dependent relocations. Architectures with fixed width instructions
/ have the inherent issue that a 32-bit (or 64-bit!) displacement cannot be
/ stuffed into a 32-bit instruction, so an address needs to be spread across
/ several instructions, and in turn this requires a sequence of relocations, each
/ updating a part of an instruction. This leads to relocation codes that are
/ inherently processor specific.
/ Arm64.
/ 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
/ PPC64.
/ 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
/ RISC-V.
/ 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
/ Loong64.
/ R_ADDRLOONG64 resolves to the low 12 bits of an external address, by encoding
/ it into the instruction.
R_ADDRLOONG64
/ R_ADDRLOONG64U resolves to the sign-adjusted "upper" 20 bits (bit 5-24) of an
/ external address, by encoding it into the instruction.
R_ADDRLOONG64U
/ R_ADDRLOONG64TLS resolves to the low 12 bits of a TLS address (offset from
/ thread pointer), by encoding it into the instruction.
R_ADDRLOONG64TLS
/ R_ADDRLOONG64TLSU resolves to the high 20 bits of a TLS address (offset from
/ thread pointer), by encoding it into the instruction.
R_ADDRLOONG64TLSU
/ R_CALLLOONG64 resolves to non-PC-relative target address of a CALL (BL/JIRL)
/ instruction, by encoding the address into the instruction.
R_CALLLOONG64
/ R_JMPLOONG64 resolves to non-PC-relative target address of a JMP instruction,
/ by encoding the address into the instruction.
R_JMPLOONG64
/ 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
)
/ 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 (r RelocType) IsDirectCall() bool {
switch r {
case R_CALL, R_CALLARM, R_CALLARM64, R_CALLLOONG64, R_CALLMIPS, R_CALLPOWER, R_RISCV_CALL, R_RISCV_CALL_TRAMP:
return true
}
return false
}
/ 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.
func (r RelocType) IsDirectJump() bool {
switch r {
case R_JMPMIPS:
return true
case R_JMPLOONG64:
return true
}
return false
}
/ IsDirectCallOrJump reports whether r is a relocation for a direct
/ call or a direct jump.
func (r RelocType) IsDirectCallOrJump() bool {
return r.IsDirectCall() || r.IsDirectJump()
}