| //===- Relocations.h -------------------------------------------*- C++ -*-===// |
| // |
| // The LLVM Linker |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLD_ELF_RELOCATIONS_H |
| #define LLD_ELF_RELOCATIONS_H |
| |
| #include "lld/Core/LLVM.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include <map> |
| #include <vector> |
| |
| namespace lld { |
| namespace elf { |
| class SymbolBody; |
| class InputSection; |
| class InputSectionBase; |
| class OutputSection; |
| |
| // List of target-independent relocation types. Relocations read |
| // from files are converted to these types so that the main code |
| // doesn't have to know about architecture-specific details. |
| enum RelExpr { |
| R_ABS, |
| R_GOT, |
| R_GOTONLY_PC, |
| R_GOTONLY_PC_FROM_END, |
| R_GOTREL, |
| R_GOTREL_FROM_END, |
| R_GOT_FROM_END, |
| R_GOT_OFF, |
| R_GOT_PAGE_PC, |
| R_GOT_PC, |
| R_HINT, |
| R_MIPS_GOTREL, |
| R_MIPS_GOT_GP, |
| R_MIPS_GOT_GP_PC, |
| R_MIPS_GOT_LOCAL_PAGE, |
| R_MIPS_GOT_OFF, |
| R_MIPS_GOT_OFF32, |
| R_MIPS_TLSGD, |
| R_MIPS_TLSLD, |
| R_NEG_TLS, |
| R_NONE, |
| R_PAGE_PC, |
| R_PC, |
| R_PLT, |
| R_PLT_PAGE_PC, |
| R_PLT_PC, |
| R_PPC_OPD, |
| R_PPC_PLT_OPD, |
| R_PPC_TOC, |
| R_RELAX_GOT_PC, |
| R_RELAX_GOT_PC_NOPIC, |
| R_RELAX_TLS_GD_TO_IE, |
| R_RELAX_TLS_GD_TO_IE_ABS, |
| R_RELAX_TLS_GD_TO_IE_END, |
| R_RELAX_TLS_GD_TO_IE_PAGE_PC, |
| R_RELAX_TLS_GD_TO_LE, |
| R_RELAX_TLS_GD_TO_LE_NEG, |
| R_RELAX_TLS_IE_TO_LE, |
| R_RELAX_TLS_LD_TO_LE, |
| R_SIZE, |
| R_TLS, |
| R_TLSDESC, |
| R_TLSDESC_CALL, |
| R_TLSDESC_PAGE, |
| R_TLSGD, |
| R_TLSGD_PC, |
| R_TLSLD, |
| R_TLSLD_PC, |
| }; |
| |
| // Build a bitmask with one bit set for each RelExpr. |
| // |
| // Constexpr function arguments can't be used in static asserts, so we |
| // use template arguments to build the mask. |
| // But function template partial specializations don't exist (needed |
| // for base case of the recursion), so we need a dummy struct. |
| template <RelExpr... Exprs> struct RelExprMaskBuilder { |
| static inline uint64_t build() { return 0; } |
| }; |
| |
| // Specialization for recursive case. |
| template <RelExpr Head, RelExpr... Tail> |
| struct RelExprMaskBuilder<Head, Tail...> { |
| static inline uint64_t build() { |
| static_assert(0 <= Head && Head < 64, |
| "RelExpr is too large for 64-bit mask!"); |
| return (uint64_t(1) << Head) | RelExprMaskBuilder<Tail...>::build(); |
| } |
| }; |
| |
| // Return true if `Expr` is one of `Exprs`. |
| // There are fewer than 64 RelExpr's, so we can represent any set of |
| // RelExpr's as a constant bit mask and test for membership with a |
| // couple cheap bitwise operations. |
| template <RelExpr... Exprs> bool isRelExprOneOf(RelExpr Expr) { |
| assert(0 <= Expr && (int)Expr < 64 && "RelExpr is too large for 64-bit mask!"); |
| return (uint64_t(1) << Expr) & RelExprMaskBuilder<Exprs...>::build(); |
| } |
| |
| // Architecture-neutral representation of relocation. |
| struct Relocation { |
| RelExpr Expr; |
| uint32_t Type; |
| uint64_t Offset; |
| int64_t Addend; |
| SymbolBody *Sym; |
| }; |
| |
| template <class ELFT> void scanRelocations(InputSectionBase &); |
| |
| class ThunkSection; |
| class Thunk; |
| |
| template <class ELFT> class ThunkCreator { |
| public: |
| // Return true if Thunks have been added to OutputSections |
| bool createThunks(ArrayRef<OutputSection *> OutputSections); |
| |
| private: |
| void mergeThunks(OutputSection *OS, std::vector<ThunkSection *> &Thunks); |
| ThunkSection *getOSThunkSec(ThunkSection *&TS, OutputSection *OS); |
| ThunkSection *getISThunkSec(InputSection *IS, OutputSection *OS); |
| std::pair<Thunk *, bool> getThunk(SymbolBody &Body, uint32_t Type); |
| |
| // Track Symbols that already have a Thunk |
| llvm::DenseMap<SymbolBody *, Thunk *> ThunkedSymbols; |
| |
| // Track InputSections that have a ThunkSection placed in front |
| llvm::DenseMap<InputSection *, ThunkSection *> ThunkedSections; |
| |
| // Track the ThunksSections that need to be inserted into an OutputSection |
| std::map<OutputSection *, std::vector<ThunkSection *>> ThunkSections; |
| }; |
| |
| // Return a int64_t to make sure we get the sign extension out of the way as |
| // early as possible. |
| template <class ELFT> |
| static inline int64_t getAddend(const typename ELFT::Rel &Rel) { |
| return 0; |
| } |
| template <class ELFT> |
| static inline int64_t getAddend(const typename ELFT::Rela &Rel) { |
| return Rel.r_addend; |
| } |
| } |
| } |
| |
| #endif |