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//===-- llvm/Target/TargetLoweringObjectFile.h - Object Info ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements classes used to handle lowerings specific to common
// object file formats.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TARGET_TARGETLOWERINGOBJECTFILE_H
#define LLVM_TARGET_TARGETLOWERINGOBJECTFILE_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/SectionKind.h"
namespace llvm {
class MachineModuleInfo;
class Mangler;
class MCContext;
class MCExpr;
class MCSection;
class MCSymbol;
class MCSymbolRefExpr;
class MCStreamer;
class ConstantExpr;
class GlobalValue;
class TargetMachine;
class TargetLoweringObjectFile : public MCObjectFileInfo {
MCContext *Ctx;
const DataLayout *DL;
TargetLoweringObjectFile(
const TargetLoweringObjectFile&) = delete;
void operator=(const TargetLoweringObjectFile&) = delete;
protected:
bool SupportIndirectSymViaGOTPCRel;
public:
MCContext &getContext() const { return *Ctx; }
TargetLoweringObjectFile() : MCObjectFileInfo(), Ctx(nullptr), DL(nullptr),
SupportIndirectSymViaGOTPCRel(false) {}
virtual ~TargetLoweringObjectFile();
/// This method must be called before any actual lowering is done. This
/// specifies the current context for codegen, and gives the lowering
/// implementations a chance to set up their default sections.
virtual void Initialize(MCContext &ctx, const TargetMachine &TM);
virtual void emitPersonalityValue(MCStreamer &Streamer,
const TargetMachine &TM,
const MCSymbol *Sym) const;
/// Extract the dependent library name from a linker option string. Returns
/// StringRef() if the option does not specify a library.
virtual StringRef getDepLibFromLinkerOpt(StringRef LinkerOption) const {
return StringRef();
}
/// Emit the module flags that the platform cares about.
virtual void emitModuleFlags(MCStreamer &Streamer,
ArrayRef<Module::ModuleFlagEntry> Flags,
Mangler &Mang, const TargetMachine &TM) const {}
/// Given a constant with the SectionKind, return a section that it should be
/// placed in.
virtual const MCSection *getSectionForConstant(SectionKind Kind,
const Constant *C) const;
/// Classify the specified global variable into a set of target independent
/// categories embodied in SectionKind.
static SectionKind getKindForGlobal(const GlobalValue *GV,
const TargetMachine &TM);
/// This method computes the appropriate section to emit the specified global
/// variable or function definition. This should not be passed external (or
/// available externally) globals.
const MCSection *SectionForGlobal(const GlobalValue *GV,
SectionKind Kind, Mangler &Mang,
const TargetMachine &TM) const;
/// This method computes the appropriate section to emit the specified global
/// variable or function definition. This should not be passed external (or
/// available externally) globals.
const MCSection *SectionForGlobal(const GlobalValue *GV,
Mangler &Mang,
const TargetMachine &TM) const {
return SectionForGlobal(GV, getKindForGlobal(GV, TM), Mang, TM);
}
virtual const MCSection *
getSectionForJumpTable(const Function &F, Mangler &Mang,
const TargetMachine &TM) const;
virtual bool shouldPutJumpTableInFunctionSection(bool UsesLabelDifference,
const Function &F) const;
/// Targets should implement this method to assign a section to globals with
/// an explicit section specfied. The implementation of this method can
/// assume that GV->hasSection() is true.
virtual const MCSection *
getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler &Mang, const TargetMachine &TM) const = 0;
/// Allow the target to completely override section assignment of a global.
virtual const MCSection *getSpecialCasedSectionGlobals(const GlobalValue *GV,
SectionKind Kind,
Mangler &Mang) const {
return nullptr;
}
/// Return an MCExpr to use for a reference to the specified global variable
/// from exception handling information.
virtual const MCExpr *
getTTypeGlobalReference(const GlobalValue *GV, unsigned Encoding,
Mangler &Mang, const TargetMachine &TM,
MachineModuleInfo *MMI, MCStreamer &Streamer) const;
/// Return the MCSymbol for a private symbol with global value name as its
/// base, with the specified suffix.
MCSymbol *getSymbolWithGlobalValueBase(const GlobalValue *GV,
StringRef Suffix, Mangler &Mang,
const TargetMachine &TM) const;
// The symbol that gets passed to .cfi_personality.
virtual MCSymbol *getCFIPersonalitySymbol(const GlobalValue *GV,
Mangler &Mang,
const TargetMachine &TM,
MachineModuleInfo *MMI) const;
const MCExpr *
getTTypeReference(const MCSymbolRefExpr *Sym, unsigned Encoding,
MCStreamer &Streamer) const;
virtual const MCSection *getStaticCtorSection(unsigned Priority,
const MCSymbol *KeySym) const {
return StaticCtorSection;
}
virtual const MCSection *getStaticDtorSection(unsigned Priority,
const MCSymbol *KeySym) const {
return StaticDtorSection;
}
/// \brief Create a symbol reference to describe the given TLS variable when
/// emitting the address in debug info.
virtual const MCExpr *getDebugThreadLocalSymbol(const MCSymbol *Sym) const;
virtual const MCExpr *
getExecutableRelativeSymbol(const ConstantExpr *CE, Mangler &Mang,
const TargetMachine &TM) const {
return nullptr;
}
/// \brief Target supports replacing a data "PC"-relative access to a symbol
/// through another symbol, by accessing the later via a GOT entry instead?
bool supportIndirectSymViaGOTPCRel() const {
return SupportIndirectSymViaGOTPCRel;
}
/// \brief Get the target specific PC relative GOT entry relocation
virtual const MCExpr *getIndirectSymViaGOTPCRel(const MCSymbol *Sym,
int64_t Offset) const {
return nullptr;
}
protected:
virtual const MCSection *
SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler &Mang, const TargetMachine &TM) const = 0;
};
} // end namespace llvm
#endif
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