157 lines
4.2 KiB
C++
157 lines
4.2 KiB
C++
//===- 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
|