1 //===-LTOCodeGenerator.h - LLVM Link Time Optimizer -----------------------===//
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 declares the LTOCodeGenerator class.
12 // LTO compilation consists of three phases: Pre-IPO, IPO and Post-IPO.
14 // The Pre-IPO phase compiles source code into bitcode file. The resulting
15 // bitcode files, along with object files and libraries, will be fed to the
16 // linker to through the IPO and Post-IPO phases. By using obj-file extension,
17 // the resulting bitcode file disguises itself as an object file, and therefore
18 // obviates the need of writing a special set of the make-rules only for LTO
21 // The IPO phase perform inter-procedural analyses and optimizations, and
22 // the Post-IPO consists two sub-phases: intra-procedural scalar optimizations
23 // (SOPT), and intra-procedural target-dependent code generator (CG).
25 // As of this writing, we don't separate IPO and the Post-IPO SOPT. They
26 // are intermingled together, and are driven by a single pass manager (see
27 // PassManagerBuilder::populateLTOPassManager()).
29 // The "LTOCodeGenerator" is the driver for the IPO and Post-IPO stages.
30 // The "CodeGenerator" here is bit confusing. Don't confuse the "CodeGenerator"
31 // with the machine specific code generator.
33 //===----------------------------------------------------------------------===//
35 #ifndef LTO_CODE_GENERATOR_H
36 #define LTO_CODE_GENERATOR_H
38 #include "llvm-c/lto.h"
39 #include "llvm/ADT/ArrayRef.h"
40 #include "llvm/ADT/SmallPtrSet.h"
41 #include "llvm/ADT/StringMap.h"
42 #include "llvm/Linker.h"
43 #include "llvm/Target/TargetOptions.h"
53 class TargetLibraryInfo;
58 //===----------------------------------------------------------------------===//
59 /// LTOCodeGenerator - C++ class which implements the opaque lto_code_gen_t
62 struct LTOCodeGenerator {
63 static const char *getVersionString();
68 // Merge given module, return true on success.
69 bool addModule(struct LTOModule*, std::string &errMsg);
71 void setTargetOptions(llvm::TargetOptions options);
72 void setDebugInfo(lto_debug_model);
73 void setCodePICModel(lto_codegen_model);
74 void setInternalizeStrategy(lto_internalize_strategy);
76 void setCpu(const char *mCpu) { MCpu = mCpu; }
78 void addMustPreserveSymbol(const char *sym) { MustPreserveSymbols[sym] = 1; }
80 // To pass options to the driver and optimization passes. These options are
81 // not necessarily for debugging purpose (The function name is misleading).
82 // This function should be called before LTOCodeGenerator::compilexxx(),
83 // and LTOCodeGenerator::writeMergedModules().
84 void setCodeGenDebugOptions(const char *opts);
86 // Parse the options set in setCodeGenDebugOptions. Like
87 // setCodeGenDebugOptions, this must be called before
88 // LTOCodeGenerator::compilexxx() and LTOCodeGenerator::writeMergedModules()
89 void parseCodeGenDebugOptions();
91 // Write the merged module to the file specified by the given path.
92 // Return true on success.
93 bool writeMergedModules(const char *path, std::string &errMsg);
95 // Compile the merged module into a *single* object file; the path to object
96 // file is returned to the caller via argument "name". Return true on
99 // NOTE that it is up to the linker to remove the intermediate object file.
100 // Do not try to remove the object file in LTOCodeGenerator's destructor
101 // as we don't who (LTOCodeGenerator or the obj file) will last longer.
102 bool compile_to_file(const char **name,
105 bool disableGVNLoadPRE,
106 std::string &errMsg);
108 // As with compile_to_file(), this function compiles the merged module into
109 // single object file. Instead of returning the object-file-path to the caller
110 // (linker), it brings the object to a buffer, and return the buffer to the
111 // caller. This function should delete intermediate object file once its content
112 // is brought to memory. Return NULL if the compilation was not successful.
113 const void *compile(size_t *length,
116 bool disableGVNLoadPRE,
117 std::string &errMsg);
119 void setDiagnosticHandler(lto_diagnostic_handler_t, void *);
121 bool shouldInternalize() const {
122 return InternalizeStrategy != LTO_INTERNALIZE_NONE;
125 bool shouldOnlyInternalizeHidden() const {
126 return InternalizeStrategy == LTO_INTERNALIZE_HIDDEN;
130 void initializeLTOPasses();
132 bool generateObjectFile(llvm::raw_ostream &out,
135 bool disableGVNLoadPRE,
136 std::string &errMsg);
137 void applyScopeRestrictions();
138 void applyRestriction(llvm::GlobalValue &GV,
139 const llvm::ArrayRef<llvm::StringRef> &Libcalls,
140 std::vector<const char*> &MustPreserveList,
141 llvm::SmallPtrSet<llvm::GlobalValue*, 8> &AsmUsed,
142 llvm::Mangler &Mangler);
143 bool determineTarget(std::string &errMsg);
145 static void DiagnosticHandler(const llvm::DiagnosticInfo &DI, void *Context);
147 void DiagnosticHandler2(const llvm::DiagnosticInfo &DI);
149 typedef llvm::StringMap<uint8_t> StringSet;
151 llvm::LLVMContext &Context;
153 llvm::TargetMachine *TargetMach;
154 bool EmitDwarfDebugInfo;
155 bool ScopeRestrictionsDone;
156 lto_codegen_model CodeModel;
157 lto_internalize_strategy InternalizeStrategy;
158 StringSet MustPreserveSymbols;
159 StringSet AsmUndefinedRefs;
160 llvm::MemoryBuffer *NativeObjectFile;
161 std::vector<char *> CodegenOptions;
163 std::string NativeObjectPath;
164 llvm::TargetOptions Options;
165 lto_diagnostic_handler_t DiagHandler;
169 #endif // LTO_CODE_GENERATOR_H