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(nullptr), DL(nullptr) {}
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 /// Given a constant with the SectionKind, return a section that it should be
73 virtual const MCSection *getSectionForConstant(SectionKind Kind,
74 const Constant *C) const;
76 /// Classify the specified global variable into a set of target independent
77 /// categories embodied in SectionKind.
78 static SectionKind getKindForGlobal(const GlobalValue *GV,
79 const TargetMachine &TM);
81 /// This method computes the appropriate section to emit the specified global
82 /// variable or function definition. This should not be passed external (or
83 /// available externally) globals.
84 const MCSection *SectionForGlobal(const GlobalValue *GV,
85 SectionKind Kind, Mangler &Mang,
86 const TargetMachine &TM) const;
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,
93 const TargetMachine &TM) const {
94 return SectionForGlobal(GV, getKindForGlobal(GV, TM), Mang, TM);
97 /// Targets should implement this method to assign a section to globals with
98 /// an explicit section specfied. The implementation of this method can
99 /// assume that GV->hasSection() is true.
100 virtual const MCSection *
101 getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
102 Mangler &Mang, const TargetMachine &TM) const = 0;
104 /// Allow the target to completely override section assignment of a global.
105 virtual const MCSection *getSpecialCasedSectionGlobals(const GlobalValue *GV,
107 Mangler &Mang) const {
111 /// Return an MCExpr to use for a reference to the specified global variable
112 /// from exception handling information.
113 virtual const MCExpr *
114 getTTypeGlobalReference(const GlobalValue *GV, unsigned Encoding,
115 Mangler &Mang, const TargetMachine &TM,
116 MachineModuleInfo *MMI, MCStreamer &Streamer) const;
118 /// Return the MCSymbol for a private symbol with global value name as its
119 /// base, with the specified suffix.
120 MCSymbol *getSymbolWithGlobalValueBase(const GlobalValue *GV,
121 StringRef Suffix, Mangler &Mang,
122 const TargetMachine &TM) const;
124 // The symbol that gets passed to .cfi_personality.
125 virtual MCSymbol *getCFIPersonalitySymbol(const GlobalValue *GV,
127 const TargetMachine &TM,
128 MachineModuleInfo *MMI) const;
131 getTTypeReference(const MCSymbolRefExpr *Sym, unsigned Encoding,
132 MCStreamer &Streamer) const;
134 virtual const MCSection *getStaticCtorSection(unsigned Priority,
135 const MCSymbol *KeySym) const {
136 return StaticCtorSection;
139 virtual const MCSection *getStaticDtorSection(unsigned Priority,
140 const MCSymbol *KeySym) const {
141 return StaticDtorSection;
144 /// \brief Create a symbol reference to describe the given TLS variable when
145 /// emitting the address in debug info.
146 virtual const MCExpr *getDebugThreadLocalSymbol(const MCSymbol *Sym) const;
148 virtual const MCExpr *
149 getExecutableRelativeSymbol(const ConstantExpr *CE, Mangler &Mang,
150 const TargetMachine &TM) const {
154 /// \brief True if the section is atomized using the symbols in it.
155 /// This is false if the section is not atomized at all (most ELF sections) or
156 /// if it is atomized based on its contents (MachO' __TEXT,__cstring for
158 virtual bool isSectionAtomizableBySymbols(const MCSection &Section) const;
161 virtual const MCSection *
162 SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
163 Mangler &Mang, const TargetMachine &TM) const = 0;
166 } // end namespace llvm