llvm-6502/include/llvm/Target/TargetLoweringObjectFile.h
Chris Lattner aac138e84d Cleanup handling of .zerofill on darwin:
1. TargetLoweringObjectFileMachO should decide if something
   goes in zerofill instead of having every target do it.
2. TargetLoweringObjectFileMachO should assign said symbols to
   the right MCSection, the asmprinters should just emit to the
   right section.
3. Since all zerofill stuff goes through mcstreamer anymore,
   MAI can have a bool "haszerofill" instead of having the textual
   directive to emit.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93838 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-19 02:09:44 +00:00

369 lines
14 KiB
C++

//===-- 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/StringRef.h"
#include "llvm/MC/SectionKind.h"
namespace llvm {
class MachineModuleInfo;
class Mangler;
class MCAsmInfo;
class MCExpr;
class MCSection;
class MCSectionMachO;
class MCContext;
class GlobalValue;
class TargetMachine;
class TargetLoweringObjectFile {
MCContext *Ctx;
TargetLoweringObjectFile(const TargetLoweringObjectFile&); // DO NOT IMPLEMENT
void operator=(const TargetLoweringObjectFile&); // DO NOT IMPLEMENT
protected:
TargetLoweringObjectFile();
/// TextSection - Section directive for standard text.
///
const MCSection *TextSection;
/// DataSection - Section directive for standard data.
///
const MCSection *DataSection;
/// BSSSection - Section that is default initialized to zero.
const MCSection *BSSSection;
/// ReadOnlySection - Section that is readonly and can contain arbitrary
/// initialized data. Targets are not required to have a readonly section.
/// If they don't, various bits of code will fall back to using the data
/// section for constants.
const MCSection *ReadOnlySection;
/// StaticCtorSection - This section contains the static constructor pointer
/// list.
const MCSection *StaticCtorSection;
/// StaticDtorSection - This section contains the static destructor pointer
/// list.
const MCSection *StaticDtorSection;
/// LSDASection - If exception handling is supported by the target, this is
/// the section the Language Specific Data Area information is emitted to.
const MCSection *LSDASection;
/// EHFrameSection - If exception handling is supported by the target, this is
/// the section the EH Frame is emitted to.
const MCSection *EHFrameSection;
// Dwarf sections for debug info. If a target supports debug info, these must
// be set.
const MCSection *DwarfAbbrevSection;
const MCSection *DwarfInfoSection;
const MCSection *DwarfLineSection;
const MCSection *DwarfFrameSection;
const MCSection *DwarfPubNamesSection;
const MCSection *DwarfPubTypesSection;
const MCSection *DwarfDebugInlineSection;
const MCSection *DwarfStrSection;
const MCSection *DwarfLocSection;
const MCSection *DwarfARangesSection;
const MCSection *DwarfRangesSection;
const MCSection *DwarfMacroInfoSection;
public:
MCContext &getContext() const { return *Ctx; }
virtual ~TargetLoweringObjectFile();
/// Initialize - 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) {
Ctx = &ctx;
}
const MCSection *getTextSection() const { return TextSection; }
const MCSection *getDataSection() const { return DataSection; }
const MCSection *getBSSSection() const { return BSSSection; }
const MCSection *getStaticCtorSection() const { return StaticCtorSection; }
const MCSection *getStaticDtorSection() const { return StaticDtorSection; }
const MCSection *getLSDASection() const { return LSDASection; }
const MCSection *getEHFrameSection() const { return EHFrameSection; }
const MCSection *getDwarfAbbrevSection() const { return DwarfAbbrevSection; }
const MCSection *getDwarfInfoSection() const { return DwarfInfoSection; }
const MCSection *getDwarfLineSection() const { return DwarfLineSection; }
const MCSection *getDwarfFrameSection() const { return DwarfFrameSection; }
const MCSection *getDwarfPubNamesSection() const{return DwarfPubNamesSection;}
const MCSection *getDwarfPubTypesSection() const{return DwarfPubTypesSection;}
const MCSection *getDwarfDebugInlineSection() const {
return DwarfDebugInlineSection;
}
const MCSection *getDwarfStrSection() const { return DwarfStrSection; }
const MCSection *getDwarfLocSection() const { return DwarfLocSection; }
const MCSection *getDwarfARangesSection() const { return DwarfARangesSection;}
const MCSection *getDwarfRangesSection() const { return DwarfRangesSection; }
const MCSection *getDwarfMacroInfoSection() const {
return DwarfMacroInfoSection;
}
/// shouldEmitUsedDirectiveFor - This hook allows targets to selectively
/// decide not to emit the UsedDirective for some symbols in llvm.used.
/// FIXME: REMOVE this (rdar://7071300)
virtual bool shouldEmitUsedDirectiveFor(const GlobalValue *GV,
Mangler *) const {
return GV != 0;
}
/// getSectionForConstant - Given a constant with the SectionKind, return a
/// section that it should be placed in.
virtual const MCSection *getSectionForConstant(SectionKind Kind) const;
/// getKindForGlobal - Classify the specified global variable into a set of
/// target independent categories embodied in SectionKind.
static SectionKind getKindForGlobal(const GlobalValue *GV,
const TargetMachine &TM);
/// SectionForGlobal - 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;
/// SectionForGlobal - 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);
}
/// getExplicitSectionGlobal - 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;
/// getSpecialCasedSectionGlobals - Allow the target to completely override
/// section assignment of a global.
virtual const MCSection *
getSpecialCasedSectionGlobals(const GlobalValue *GV, Mangler *Mang,
SectionKind Kind) const {
return 0;
}
/// getSymbolForDwarfGlobalReference - Return an MCExpr to use for a
/// pc-relative reference to the specified global variable from exception
/// handling information. In addition to the symbol, this returns
/// by-reference:
///
/// IsIndirect - True if the returned symbol is actually a stub that contains
/// the address of the symbol, false if the symbol is the global itself.
///
/// IsPCRel - True if the symbol reference is already pc-relative, false if
/// the caller needs to subtract off the address of the reference from the
/// symbol.
///
virtual const MCExpr *
getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
MachineModuleInfo *MMI,
bool &IsIndirect, bool &IsPCRel) const;
protected:
virtual const MCSection *
SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler *Mang, const TargetMachine &TM) const;
};
class TargetLoweringObjectFileELF : public TargetLoweringObjectFile {
mutable void *UniquingMap;
protected:
/// TLSDataSection - Section directive for Thread Local data.
///
const MCSection *TLSDataSection; // Defaults to ".tdata".
/// TLSBSSSection - Section directive for Thread Local uninitialized data.
/// Null if this target doesn't support a BSS section.
///
const MCSection *TLSBSSSection; // Defaults to ".tbss".
const MCSection *DataRelSection;
const MCSection *DataRelLocalSection;
const MCSection *DataRelROSection;
const MCSection *DataRelROLocalSection;
const MCSection *MergeableConst4Section;
const MCSection *MergeableConst8Section;
const MCSection *MergeableConst16Section;
protected:
const MCSection *getELFSection(StringRef Section, unsigned Type,
unsigned Flags, SectionKind Kind,
bool IsExplicit = false) const;
public:
TargetLoweringObjectFileELF() : UniquingMap(0) {}
~TargetLoweringObjectFileELF();
virtual void Initialize(MCContext &Ctx, const TargetMachine &TM);
/// getSectionForConstant - Given a constant with the SectionKind, return a
/// section that it should be placed in.
virtual const MCSection *getSectionForConstant(SectionKind Kind) const;
virtual const MCSection *
getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler *Mang, const TargetMachine &TM) const;
virtual const MCSection *
SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler *Mang, const TargetMachine &TM) const;
};
class TargetLoweringObjectFileMachO : public TargetLoweringObjectFile {
mutable void *UniquingMap;
const MCSection *CStringSection;
const MCSection *UStringSection;
const MCSection *TextCoalSection;
const MCSection *ConstTextCoalSection;
const MCSection *ConstDataCoalSection;
const MCSection *ConstDataSection;
const MCSection *DataCoalSection;
const MCSection *DataCommonSection;
const MCSection *FourByteConstantSection;
const MCSection *EightByteConstantSection;
const MCSection *SixteenByteConstantSection;
const MCSection *LazySymbolPointerSection;
const MCSection *NonLazySymbolPointerSection;
public:
TargetLoweringObjectFileMachO() : UniquingMap(0) {}
~TargetLoweringObjectFileMachO();
virtual void Initialize(MCContext &Ctx, const TargetMachine &TM);
virtual const MCSection *
SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler *Mang, const TargetMachine &TM) const;
virtual const MCSection *
getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler *Mang, const TargetMachine &TM) const;
virtual const MCSection *getSectionForConstant(SectionKind Kind) const;
/// shouldEmitUsedDirectiveFor - This hook allows targets to selectively
/// decide not to emit the UsedDirective for some symbols in llvm.used.
/// FIXME: REMOVE this (rdar://7071300)
virtual bool shouldEmitUsedDirectiveFor(const GlobalValue *GV,
Mangler *) const;
/// getMachOSection - Return the MCSection for the specified mach-o section.
/// This requires the operands to be valid.
const MCSectionMachO *getMachOSection(StringRef Segment,
StringRef Section,
unsigned TypeAndAttributes,
SectionKind K) const {
return getMachOSection(Segment, Section, TypeAndAttributes, 0, K);
}
const MCSectionMachO *getMachOSection(StringRef Segment,
StringRef Section,
unsigned TypeAndAttributes,
unsigned Reserved2,
SectionKind K) const;
/// getTextCoalSection - Return the "__TEXT,__textcoal_nt" section we put weak
/// text symbols into.
const MCSection *getTextCoalSection() const {
return TextCoalSection;
}
/// getConstTextCoalSection - Return the "__TEXT,__const_coal" section
/// we put weak read-only symbols into.
const MCSection *getConstTextCoalSection() const {
return ConstTextCoalSection;
}
/// getDataCommonSection - Return the "__DATA,__common" section we put
/// zerofill (aka bss) data into.
const MCSection *getDataCommonSection() const {
return DataCommonSection;
}
/// getLazySymbolPointerSection - Return the section corresponding to
/// the .lazy_symbol_pointer directive.
const MCSection *getLazySymbolPointerSection() const {
return LazySymbolPointerSection;
}
/// getNonLazySymbolPointerSection - Return the section corresponding to
/// the .non_lazy_symbol_pointer directive.
const MCSection *getNonLazySymbolPointerSection() const {
return NonLazySymbolPointerSection;
}
/// getSymbolForDwarfGlobalReference - The mach-o version of this method
/// defaults to returning a stub reference.
virtual const MCExpr *
getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
MachineModuleInfo *MMI,
bool &IsIndirect, bool &IsPCRel) const;
};
class TargetLoweringObjectFileCOFF : public TargetLoweringObjectFile {
mutable void *UniquingMap;
public:
TargetLoweringObjectFileCOFF() : UniquingMap(0) {}
~TargetLoweringObjectFileCOFF();
virtual void Initialize(MCContext &Ctx, const TargetMachine &TM);
virtual const MCSection *
getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler *Mang, const TargetMachine &TM) const;
virtual const MCSection *
SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler *Mang, const TargetMachine &TM) const;
/// getCOFFSection - Return the MCSection for the specified COFF section.
/// FIXME: Switch this to a semantic view eventually.
const MCSection *getCOFFSection(StringRef Name, bool isDirective,
SectionKind K) const;
};
} // end namespace llvm
#endif