1 //===-- llvm/Target/TargetLoweringObjectFile.h - Object Info ----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements classes used to handle lowerings specific to common
11 // object file formats.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_TARGET_TARGETLOWERINGOBJECTFILE_H
16 #define LLVM_TARGET_TARGETLOWERINGOBJECTFILE_H
18 #include "llvm/ADT/ArrayRef.h"
19 #include "llvm/IR/Module.h"
20 #include "llvm/MC/MCObjectFileInfo.h"
21 #include "llvm/MC/SectionKind.h"
24 class MachineModuleInfo;
30 class MCSymbolRefExpr;
36 class TargetLoweringObjectFile : public MCObjectFileInfo {
40 TargetLoweringObjectFile(
41 const TargetLoweringObjectFile&) LLVM_DELETED_FUNCTION;
42 void operator=(const TargetLoweringObjectFile&) LLVM_DELETED_FUNCTION;
45 MCContext &getContext() const { return *Ctx; }
47 TargetLoweringObjectFile() : MCObjectFileInfo(), Ctx(0), DL(0) {}
49 virtual ~TargetLoweringObjectFile();
51 /// This method must be called before any actual lowering is done. This
52 /// specifies the current context for codegen, and gives the lowering
53 /// implementations a chance to set up their default sections.
54 virtual void Initialize(MCContext &ctx, const TargetMachine &TM);
56 virtual void emitPersonalityValue(MCStreamer &Streamer,
57 const TargetMachine &TM,
58 const MCSymbol *Sym) const;
60 /// Extract the dependent library name from a linker option string. Returns
61 /// StringRef() if the option does not specify a library.
62 virtual StringRef getDepLibFromLinkerOpt(StringRef LinkerOption) const {
66 /// Emit the module flags that the platform cares about.
67 virtual void emitModuleFlags(MCStreamer &Streamer,
68 ArrayRef<Module::ModuleFlagEntry> Flags,
69 Mangler &Mang, const TargetMachine &TM) const {}
71 /// This hook allows targets to selectively decide not to emit the
72 /// UsedDirective for some symbols in llvm.used.
73 /// FIXME: REMOVE this (rdar://7071300)
74 virtual bool shouldEmitUsedDirectiveFor(const GlobalValue *GV, Mangler &Mang,
75 TargetMachine &TM) const {
79 /// Given a constant with the SectionKind, return a section that it should be
81 virtual const MCSection *getSectionForConstant(SectionKind Kind) const;
83 /// Classify the specified global variable into a set of target independent
84 /// categories embodied in SectionKind.
85 static SectionKind getKindForGlobal(const GlobalValue *GV,
86 const TargetMachine &TM);
88 /// This method computes the appropriate section to emit the specified global
89 /// variable or function definition. This should not be passed external (or
90 /// available externally) globals.
91 const MCSection *SectionForGlobal(const GlobalValue *GV,
92 SectionKind Kind, Mangler &Mang,
93 const TargetMachine &TM) const;
95 /// This method computes the appropriate section to emit the specified global
96 /// variable or function definition. This should not be passed external (or
97 /// available externally) globals.
98 const MCSection *SectionForGlobal(const GlobalValue *GV,
100 const TargetMachine &TM) const {
101 return SectionForGlobal(GV, getKindForGlobal(GV, TM), Mang, TM);
104 /// Targets should implement this method to assign a section to globals with
105 /// an explicit section specfied. The implementation of this method can
106 /// assume that GV->hasSection() is true.
107 virtual const MCSection *
108 getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
109 Mangler &Mang, const TargetMachine &TM) const = 0;
111 /// Allow the target to completely override section assignment of a global.
112 virtual const MCSection *getSpecialCasedSectionGlobals(const GlobalValue *GV,
114 Mangler &Mang) const {
118 /// Return an MCExpr to use for a reference to the specified global variable
119 /// from exception handling information.
120 virtual const MCExpr *
121 getTTypeGlobalReference(const GlobalValue *GV, unsigned Encoding,
122 Mangler &Mang, const TargetMachine &TM,
123 MachineModuleInfo *MMI, MCStreamer &Streamer) const;
125 /// Return the MCSymbol for a private symbol with global value name as its
126 /// base, with the specified suffix.
127 MCSymbol *getSymbolWithGlobalValueBase(const GlobalValue *GV,
128 StringRef Suffix, Mangler &Mang,
129 const TargetMachine &TM) const;
131 // The symbol that gets passed to .cfi_personality.
132 virtual MCSymbol *getCFIPersonalitySymbol(const GlobalValue *GV,
134 const TargetMachine &TM,
135 MachineModuleInfo *MMI) const;
138 getTTypeReference(const MCSymbolRefExpr *Sym, unsigned Encoding,
139 MCStreamer &Streamer) const;
141 virtual const MCSection *
142 getStaticCtorSection(unsigned Priority = 65535) const {
144 return StaticCtorSection;
146 virtual const MCSection *
147 getStaticDtorSection(unsigned Priority = 65535) const {
149 return StaticDtorSection;
152 /// \brief Create a symbol reference to describe the given TLS variable when
153 /// emitting the address in debug info.
154 virtual const MCExpr *getDebugThreadLocalSymbol(const MCSymbol *Sym) const;
156 virtual const MCExpr *
157 getExecutableRelativeSymbol(const ConstantExpr *CE, Mangler &Mang,
158 const TargetMachine &TM) const {
162 /// \brief True if the section is atomized using the symbols in it.
163 /// This is false if the section is not atomized at all (most ELF sections) or
164 /// if it is atomized based on its contents (MachO' __TEXT,__cstring for
166 virtual bool isSectionAtomizableBySymbols(const MCSection &Section) const;
169 virtual const MCSection *
170 SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
171 Mangler &Mang, const TargetMachine &TM) const;
174 } // end namespace llvm