mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2026-01-31 01:35:20 +01:00
a2b91c0b40
If a global object is listed in `@llvm.used`, place it in a unique section with the `SHF_GNU_RETAIN` flag. The section is a GC root under `ld --gc-sections` with LLD>=13 or GNU ld>=2.36. For front ends which do not expect to see multiple sections of the same name, consider emitting `@llvm.compiler.used` instead of `@llvm.used`. SHF_GNU_RETAIN is restricted to ELFOSABI_GNU and ELFOSABI_FREEBSD in binutils. We don't do the restriction - see the rationale in D95749. The integrated assembler has supported SHF_GNU_RETAIN since D95730. GNU as>=2.36 supports section flag 'R'. We don't need to worry about GNU ld support because older GNU ld just ignores the unknown SHF_GNU_RETAIN. With this change, `__attribute__((retain))` functions/variables emitted by clang will get the SHF_GNU_RETAIN flag. Differential Revision: https://reviews.llvm.org/D97448
289 lines
12 KiB
C++
289 lines
12 KiB
C++
//==- llvm/CodeGen/TargetLoweringObjectFileImpl.h - Object Info --*- C++ -*-==//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements classes used to handle lowerings specific to common
|
|
// object file formats.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_CODEGEN_TARGETLOWERINGOBJECTFILEIMPL_H
|
|
#define LLVM_CODEGEN_TARGETLOWERINGOBJECTFILEIMPL_H
|
|
|
|
#include "llvm/ADT/SmallPtrSet.h"
|
|
#include "llvm/BinaryFormat/XCOFF.h"
|
|
#include "llvm/Target/TargetLoweringObjectFile.h"
|
|
|
|
namespace llvm {
|
|
|
|
class GlobalValue;
|
|
class MachineModuleInfo;
|
|
class MachineFunction;
|
|
class MCContext;
|
|
class MCExpr;
|
|
class MCSection;
|
|
class MCSymbol;
|
|
class Module;
|
|
class TargetMachine;
|
|
|
|
class TargetLoweringObjectFileELF : public TargetLoweringObjectFile {
|
|
bool UseInitArray = false;
|
|
mutable unsigned NextUniqueID = 1; // ID 0 is reserved for execute-only sections
|
|
SmallPtrSet<GlobalObject *, 2> Used;
|
|
|
|
protected:
|
|
MCSymbolRefExpr::VariantKind PLTRelativeVariantKind =
|
|
MCSymbolRefExpr::VK_None;
|
|
|
|
public:
|
|
TargetLoweringObjectFileELF();
|
|
~TargetLoweringObjectFileELF() override = default;
|
|
|
|
void Initialize(MCContext &Ctx, const TargetMachine &TM) override;
|
|
|
|
void getModuleMetadata(Module &M) override;
|
|
|
|
/// Emit Obj-C garbage collection and linker options.
|
|
void emitModuleMetadata(MCStreamer &Streamer, Module &M) const override;
|
|
|
|
void emitPersonalityValue(MCStreamer &Streamer, const DataLayout &DL,
|
|
const MCSymbol *Sym) const override;
|
|
|
|
/// Given a constant with the SectionKind, return a section that it should be
|
|
/// placed in.
|
|
MCSection *getSectionForConstant(const DataLayout &DL, SectionKind Kind,
|
|
const Constant *C,
|
|
Align &Alignment) const override;
|
|
|
|
MCSection *getExplicitSectionGlobal(const GlobalObject *GO, SectionKind Kind,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *getSectionForJumpTable(const Function &F,
|
|
const TargetMachine &TM) const override;
|
|
MCSection *getSectionForLSDA(const Function &F, const MCSymbol &FnSym,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *
|
|
getSectionForMachineBasicBlock(const Function &F,
|
|
const MachineBasicBlock &MBB,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *
|
|
getUniqueSectionForFunction(const Function &F,
|
|
const TargetMachine &TM) const override;
|
|
|
|
bool shouldPutJumpTableInFunctionSection(bool UsesLabelDifference,
|
|
const Function &F) const override;
|
|
|
|
/// Return an MCExpr to use for a reference to the specified type info global
|
|
/// variable from exception handling information.
|
|
const MCExpr *getTTypeGlobalReference(const GlobalValue *GV,
|
|
unsigned Encoding,
|
|
const TargetMachine &TM,
|
|
MachineModuleInfo *MMI,
|
|
MCStreamer &Streamer) const override;
|
|
|
|
// The symbol that gets passed to .cfi_personality.
|
|
MCSymbol *getCFIPersonalitySymbol(const GlobalValue *GV,
|
|
const TargetMachine &TM,
|
|
MachineModuleInfo *MMI) const override;
|
|
|
|
void InitializeELF(bool UseInitArray_);
|
|
MCSection *getStaticCtorSection(unsigned Priority,
|
|
const MCSymbol *KeySym) const override;
|
|
MCSection *getStaticDtorSection(unsigned Priority,
|
|
const MCSymbol *KeySym) const override;
|
|
|
|
const MCExpr *lowerRelativeReference(const GlobalValue *LHS,
|
|
const GlobalValue *RHS,
|
|
const TargetMachine &TM) const override;
|
|
|
|
const MCExpr *lowerDSOLocalEquivalent(const DSOLocalEquivalent *Equiv,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *getSectionForCommandLines() const override;
|
|
};
|
|
|
|
class TargetLoweringObjectFileMachO : public TargetLoweringObjectFile {
|
|
public:
|
|
TargetLoweringObjectFileMachO();
|
|
~TargetLoweringObjectFileMachO() override = default;
|
|
|
|
void Initialize(MCContext &Ctx, const TargetMachine &TM) override;
|
|
|
|
/// Emit the module flags that specify the garbage collection information.
|
|
void emitModuleMetadata(MCStreamer &Streamer, Module &M) const override;
|
|
|
|
MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *getExplicitSectionGlobal(const GlobalObject *GO, SectionKind Kind,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *getSectionForConstant(const DataLayout &DL, SectionKind Kind,
|
|
const Constant *C,
|
|
Align &Alignment) const override;
|
|
|
|
/// The mach-o version of this method defaults to returning a stub reference.
|
|
const MCExpr *getTTypeGlobalReference(const GlobalValue *GV,
|
|
unsigned Encoding,
|
|
const TargetMachine &TM,
|
|
MachineModuleInfo *MMI,
|
|
MCStreamer &Streamer) const override;
|
|
|
|
// The symbol that gets passed to .cfi_personality.
|
|
MCSymbol *getCFIPersonalitySymbol(const GlobalValue *GV,
|
|
const TargetMachine &TM,
|
|
MachineModuleInfo *MMI) const override;
|
|
|
|
/// Get MachO PC relative GOT entry relocation
|
|
const MCExpr *getIndirectSymViaGOTPCRel(const GlobalValue *GV,
|
|
const MCSymbol *Sym,
|
|
const MCValue &MV, int64_t Offset,
|
|
MachineModuleInfo *MMI,
|
|
MCStreamer &Streamer) const override;
|
|
|
|
void getNameWithPrefix(SmallVectorImpl<char> &OutName, const GlobalValue *GV,
|
|
const TargetMachine &TM) const override;
|
|
};
|
|
|
|
class TargetLoweringObjectFileCOFF : public TargetLoweringObjectFile {
|
|
mutable unsigned NextUniqueID = 0;
|
|
const TargetMachine *TM = nullptr;
|
|
|
|
public:
|
|
~TargetLoweringObjectFileCOFF() override = default;
|
|
|
|
void Initialize(MCContext &Ctx, const TargetMachine &TM) override;
|
|
MCSection *getExplicitSectionGlobal(const GlobalObject *GO, SectionKind Kind,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind,
|
|
const TargetMachine &TM) const override;
|
|
|
|
void getNameWithPrefix(SmallVectorImpl<char> &OutName, const GlobalValue *GV,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *getSectionForJumpTable(const Function &F,
|
|
const TargetMachine &TM) const override;
|
|
|
|
/// Emit Obj-C garbage collection and linker options.
|
|
void emitModuleMetadata(MCStreamer &Streamer, Module &M) const override;
|
|
|
|
MCSection *getStaticCtorSection(unsigned Priority,
|
|
const MCSymbol *KeySym) const override;
|
|
MCSection *getStaticDtorSection(unsigned Priority,
|
|
const MCSymbol *KeySym) const override;
|
|
|
|
const MCExpr *lowerRelativeReference(const GlobalValue *LHS,
|
|
const GlobalValue *RHS,
|
|
const TargetMachine &TM) const override;
|
|
|
|
/// Given a mergeable constant with the specified size and relocation
|
|
/// information, return a section that it should be placed in.
|
|
MCSection *getSectionForConstant(const DataLayout &DL, SectionKind Kind,
|
|
const Constant *C,
|
|
Align &Alignment) const override;
|
|
|
|
private:
|
|
void emitLinkerDirectives(MCStreamer &Streamer, Module &M) const;
|
|
};
|
|
|
|
class TargetLoweringObjectFileWasm : public TargetLoweringObjectFile {
|
|
mutable unsigned NextUniqueID = 0;
|
|
|
|
public:
|
|
TargetLoweringObjectFileWasm() = default;
|
|
~TargetLoweringObjectFileWasm() override = default;
|
|
|
|
MCSection *getExplicitSectionGlobal(const GlobalObject *GO, SectionKind Kind,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind,
|
|
const TargetMachine &TM) const override;
|
|
|
|
bool shouldPutJumpTableInFunctionSection(bool UsesLabelDifference,
|
|
const Function &F) const override;
|
|
|
|
void InitializeWasm();
|
|
MCSection *getStaticCtorSection(unsigned Priority,
|
|
const MCSymbol *KeySym) const override;
|
|
MCSection *getStaticDtorSection(unsigned Priority,
|
|
const MCSymbol *KeySym) const override;
|
|
|
|
const MCExpr *lowerRelativeReference(const GlobalValue *LHS,
|
|
const GlobalValue *RHS,
|
|
const TargetMachine &TM) const override;
|
|
};
|
|
|
|
class TargetLoweringObjectFileXCOFF : public TargetLoweringObjectFile {
|
|
public:
|
|
TargetLoweringObjectFileXCOFF() = default;
|
|
~TargetLoweringObjectFileXCOFF() override = default;
|
|
|
|
static bool ShouldEmitEHBlock(const MachineFunction *MF);
|
|
|
|
static MCSymbol *getEHInfoTableSymbol(const MachineFunction *MF);
|
|
|
|
void Initialize(MCContext &Ctx, const TargetMachine &TM) override;
|
|
|
|
bool shouldPutJumpTableInFunctionSection(bool UsesLabelDifference,
|
|
const Function &F) const override;
|
|
|
|
MCSection *getExplicitSectionGlobal(const GlobalObject *GO, SectionKind Kind,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *getStaticCtorSection(unsigned Priority,
|
|
const MCSymbol *KeySym) const override;
|
|
MCSection *getStaticDtorSection(unsigned Priority,
|
|
const MCSymbol *KeySym) const override;
|
|
|
|
const MCExpr *lowerRelativeReference(const GlobalValue *LHS,
|
|
const GlobalValue *RHS,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSection *getSectionForJumpTable(const Function &F,
|
|
const TargetMachine &TM) const override;
|
|
|
|
/// Given a constant with the SectionKind, return a section that it should be
|
|
/// placed in.
|
|
MCSection *getSectionForConstant(const DataLayout &DL, SectionKind Kind,
|
|
const Constant *C,
|
|
Align &Alignment) const override;
|
|
|
|
static XCOFF::StorageClass getStorageClassForGlobal(const GlobalValue *GV);
|
|
|
|
MCSection *
|
|
getSectionForFunctionDescriptor(const Function *F,
|
|
const TargetMachine &TM) const override;
|
|
MCSection *getSectionForTOCEntry(const MCSymbol *Sym,
|
|
const TargetMachine &TM) const override;
|
|
|
|
/// For external functions, this will always return a function descriptor
|
|
/// csect.
|
|
MCSection *
|
|
getSectionForExternalReference(const GlobalObject *GO,
|
|
const TargetMachine &TM) const override;
|
|
|
|
/// For functions, this will always return a function descriptor symbol.
|
|
MCSymbol *getTargetSymbol(const GlobalValue *GV,
|
|
const TargetMachine &TM) const override;
|
|
|
|
MCSymbol *getFunctionEntryPointSymbol(const GlobalValue *Func,
|
|
const TargetMachine &TM) const override;
|
|
};
|
|
|
|
} // end namespace llvm
|
|
|
|
#endif // LLVM_CODEGEN_TARGETLOWERINGOBJECTFILEIMPL_H
|