1 //===- Relocations.h -------------------------------------------*- C++ -*-===//
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLD_ELF_RELOCATIONS_H
11 #define LLD_ELF_RELOCATIONS_H
13 #include "lld/Core/LLVM.h"
14 #include "llvm/ADT/DenseMap.h"
22 class InputSectionBase;
25 // List of target-independent relocation types. Relocations read
26 // from files are converted to these types so that the main code
27 // doesn't have to know about architecture-specific details.
33 R_GOTONLY_PC_FROM_END,
44 R_MIPS_GOT_LOCAL_PAGE,
62 R_RELAX_TLS_GD_TO_IE_ABS,
63 R_RELAX_TLS_GD_TO_IE_END,
64 R_RELAX_TLS_GD_TO_IE_PAGE_PC,
66 R_RELAX_TLS_GD_TO_LE_NEG,
80 // Build a bitmask with one bit set for each RelExpr.
82 // Constexpr function arguments can't be used in static asserts, so we
83 // use template arguments to build the mask.
84 // But function template partial specializations don't exist (needed
85 // for base case of the recursion), so we need a dummy struct.
86 template <RelExpr... Exprs> struct RelExprMaskBuilder {
87 static inline uint64_t build() { return 0; }
90 // Specialization for recursive case.
91 template <RelExpr Head, RelExpr... Tail>
92 struct RelExprMaskBuilder<Head, Tail...> {
93 static inline uint64_t build() {
94 static_assert(0 <= Head && Head < 64,
95 "RelExpr is too large for 64-bit mask!");
96 return (uint64_t(1) << Head) | RelExprMaskBuilder<Tail...>::build();
100 // Return true if `Expr` is one of `Exprs`.
101 // There are fewer than 64 RelExpr's, so we can represent any set of
102 // RelExpr's as a constant bit mask and test for membership with a
103 // couple cheap bitwise operations.
104 template <RelExpr... Exprs> bool isRelExprOneOf(RelExpr Expr) {
105 assert(0 <= Expr && (int)Expr < 64 && "RelExpr is too large for 64-bit mask!");
106 return (uint64_t(1) << Expr) & RelExprMaskBuilder<Exprs...>::build();
109 // Architecture-neutral representation of relocation.
118 template <class ELFT> void scanRelocations(InputSectionBase &);
125 // Return true if Thunks have been added to OutputSections
126 bool createThunks(ArrayRef<OutputSection *> OutputSections);
129 void mergeThunks(OutputSection *OS, std::vector<ThunkSection *> &Thunks);
130 ThunkSection *getOSThunkSec(ThunkSection *&TS, OutputSection *OS);
131 ThunkSection *getISThunkSec(InputSection *IS, OutputSection *OS);
132 std::pair<Thunk *, bool> getThunk(SymbolBody &Body, uint32_t Type);
134 // Track Symbols that already have a Thunk
135 llvm::DenseMap<SymbolBody *, Thunk *> ThunkedSymbols;
137 // Track InputSections that have a ThunkSection placed in front
138 llvm::DenseMap<InputSection *, ThunkSection *> ThunkedSections;
140 // Track the ThunksSections that need to be inserted into an OutputSection
141 std::map<OutputSection *, std::vector<ThunkSection *>> ThunkSections;
144 // Return a int64_t to make sure we get the sign extension out of the way as
145 // early as possible.
146 template <class ELFT>
147 static inline int64_t getAddend(const typename ELFT::Rel &Rel) {
150 template <class ELFT>
151 static inline int64_t getAddend(const typename ELFT::Rela &Rel) {