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/Linker.h"
43 #include "llvm/Target/TargetOptions.h"
53 class TargetLibraryInfo;
57 //===----------------------------------------------------------------------===//
58 /// C++ class which implements the opaque lto_code_gen_t type.
60 struct LTOCodeGenerator {
61 static const char *getVersionString();
66 // Merge given module, return true on success.
67 bool addModule(struct LTOModule*, std::string &errMsg);
69 void setTargetOptions(TargetOptions options);
70 void setDebugInfo(lto_debug_model);
71 void setCodePICModel(lto_codegen_model);
73 void setCpu(const char *mCpu) { MCpu = mCpu; }
74 void setAttr(const char *mAttr) { MAttr = mAttr; }
76 void addMustPreserveSymbol(const char *sym) { MustPreserveSymbols[sym] = 1; }
78 // To pass options to the driver and optimization passes. These options are
79 // not necessarily for debugging purpose (The function name is misleading).
80 // This function should be called before LTOCodeGenerator::compilexxx(),
81 // and LTOCodeGenerator::writeMergedModules().
82 void setCodeGenDebugOptions(const char *opts);
84 // Parse the options set in setCodeGenDebugOptions. Like
85 // setCodeGenDebugOptions, this must be called before
86 // LTOCodeGenerator::compilexxx() and LTOCodeGenerator::writeMergedModules()
87 void parseCodeGenDebugOptions();
89 // Write the merged module to the file specified by the given path.
90 // Return true on success.
91 bool writeMergedModules(const char *path, std::string &errMsg);
93 // Compile the merged module into a *single* object file; the path to object
94 // file is returned to the caller via argument "name". Return true on
97 // NOTE that it is up to the linker to remove the intermediate object file.
98 // Do not try to remove the object file in LTOCodeGenerator's destructor
99 // as we don't who (LTOCodeGenerator or the obj file) will last longer.
100 bool compile_to_file(const char **name,
103 bool disableGVNLoadPRE,
104 std::string &errMsg);
106 // As with compile_to_file(), this function compiles the merged module into
107 // single object file. Instead of returning the object-file-path to the caller
108 // (linker), it brings the object to a buffer, and return the buffer to the
109 // caller. This function should delete intermediate object file once its content
110 // is brought to memory. Return NULL if the compilation was not successful.
111 const void *compile(size_t *length,
114 bool disableGVNLoadPRE,
115 std::string &errMsg);
117 void setDiagnosticHandler(lto_diagnostic_handler_t, void *);
120 void initializeLTOPasses();
122 bool generateObjectFile(raw_ostream &out, bool disableOpt, bool disableInline,
123 bool disableGVNLoadPRE, std::string &errMsg);
124 void applyScopeRestrictions();
125 void applyRestriction(GlobalValue &GV, const ArrayRef<StringRef> &Libcalls,
126 std::vector<const char *> &MustPreserveList,
127 SmallPtrSet<GlobalValue *, 8> &AsmUsed,
129 bool determineTarget(std::string &errMsg);
131 static void DiagnosticHandler(const DiagnosticInfo &DI, void *Context);
133 void DiagnosticHandler2(const DiagnosticInfo &DI);
135 typedef StringMap<uint8_t> StringSet;
137 LLVMContext &Context;
139 TargetMachine *TargetMach;
140 bool EmitDwarfDebugInfo;
141 bool ScopeRestrictionsDone;
142 lto_codegen_model CodeModel;
143 StringSet MustPreserveSymbols;
144 StringSet AsmUndefinedRefs;
145 MemoryBuffer *NativeObjectFile;
146 std::vector<char *> CodegenOptions;
149 std::string NativeObjectPath;
150 TargetOptions Options;
151 lto_diagnostic_handler_t DiagHandler;
155 #endif // LTO_CODE_GENERATOR_H