1 //===-- llc.cpp - Implement the LLVM Native Code Generator ----------------===//
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 is the llc code generator driver. It provides a convenient
11 // command-line interface for generating native assembly-language code
12 // or C code, given LLVM bitcode.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/Bitcode/ReaderWriter.h"
17 #include "llvm/CodeGen/FileWriters.h"
18 #include "llvm/CodeGen/LinkAllCodegenComponents.h"
19 #include "llvm/CodeGen/LinkAllAsmWriterComponents.h"
20 #include "llvm/Target/SubtargetFeature.h"
21 #include "llvm/Target/TargetData.h"
22 #include "llvm/Target/TargetMachine.h"
23 #include "llvm/Target/TargetMachineRegistry.h"
24 #include "llvm/Transforms/Scalar.h"
25 #include "llvm/Module.h"
26 #include "llvm/ModuleProvider.h"
27 #include "llvm/PassManager.h"
28 #include "llvm/Pass.h"
29 #include "llvm/Support/CommandLine.h"
30 #include "llvm/Support/FileUtilities.h"
31 #include "llvm/Support/ManagedStatic.h"
32 #include "llvm/Support/MemoryBuffer.h"
33 #include "llvm/Support/PluginLoader.h"
34 #include "llvm/Support/PrettyStackTrace.h"
35 #include "llvm/Support/RegistryParser.h"
36 #include "llvm/Support/raw_ostream.h"
37 #include "llvm/Analysis/Verifier.h"
38 #include "llvm/System/Signals.h"
39 #include "llvm/Config/config.h"
40 #include "llvm/LinkAllVMCore.h"
41 #include "llvm/Target/TargetSelect.h"
47 // General options for llc. Other pass-specific options are specified
48 // within the corresponding llc passes, and target-specific options
49 // and back-end code generation options are specified with the target machine.
51 static cl::opt<std::string>
52 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
54 static cl::opt<std::string>
55 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
57 static cl::opt<bool> Force("f", cl::desc("Overwrite output files"));
59 // Determine optimization level.
62 cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
68 static cl::opt<std::string>
69 TargetTriple("mtriple", cl::desc("Override target triple for module"));
71 static cl::opt<const TargetMachineRegistry::entry*, false,
72 RegistryParser<TargetMachine> >
73 MArch("march", cl::desc("Architecture to generate code for:"));
75 static cl::opt<std::string>
77 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
78 cl::value_desc("cpu-name"),
81 static cl::list<std::string>
84 cl::desc("Target specific attributes (-mattr=help for details)"),
85 cl::value_desc("a1,+a2,-a3,..."));
87 cl::opt<TargetMachine::CodeGenFileType>
88 FileType("filetype", cl::init(TargetMachine::AssemblyFile),
89 cl::desc("Choose a file type (not all types are supported by all targets):"),
91 clEnumValN(TargetMachine::AssemblyFile, "asm",
92 "Emit an assembly ('.s') file"),
93 clEnumValN(TargetMachine::ObjectFile, "obj",
94 "Emit a native object ('.o') file [experimental]"),
95 clEnumValN(TargetMachine::DynamicLibrary, "dynlib",
96 "Emit a native dynamic library ('.so') file"
100 cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
101 cl::desc("Do not verify input module"));
105 DisableRedZone("disable-red-zone",
106 cl::desc("Do not emit code that uses the red zone."),
110 NoImplicitFloats("no-implicit-float",
111 cl::desc("Don't generate implicit floating point instructions (x86-only)"),
114 // GetFileNameRoot - Helper function to get the basename of a filename.
115 static inline std::string
116 GetFileNameRoot(const std::string &InputFilename) {
117 std::string IFN = InputFilename;
118 std::string outputFilename;
119 int Len = IFN.length();
121 IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
122 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
124 outputFilename = IFN;
126 return outputFilename;
129 static raw_ostream *GetOutputStream(const char *ProgName) {
130 if (OutputFilename != "") {
131 if (OutputFilename == "-")
134 // Specified an output filename?
135 if (!Force && std::ifstream(OutputFilename.c_str())) {
136 // If force is not specified, make sure not to overwrite a file!
137 std::cerr << ProgName << ": error opening '" << OutputFilename
138 << "': file exists!\n"
139 << "Use -f command line argument to force output\n";
142 // Make sure that the Out file gets unlinked from the disk if we get a
144 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
147 raw_ostream *Out = new raw_fd_ostream(OutputFilename.c_str(), true, error);
148 if (!error.empty()) {
149 std::cerr << error << '\n';
157 if (InputFilename == "-") {
158 OutputFilename = "-";
162 OutputFilename = GetFileNameRoot(InputFilename);
166 case TargetMachine::AssemblyFile:
167 if (MArch->Name[0] == 'c') {
168 if (MArch->Name[1] == 0)
169 OutputFilename += ".cbe.c";
170 else if (MArch->Name[1] == 'p' && MArch->Name[2] == 'p')
171 OutputFilename += ".cpp";
173 OutputFilename += ".s";
175 OutputFilename += ".s";
177 case TargetMachine::ObjectFile:
178 OutputFilename += ".o";
181 case TargetMachine::DynamicLibrary:
182 OutputFilename += LTDL_SHLIB_EXT;
187 if (!Force && std::ifstream(OutputFilename.c_str())) {
188 // If force is not specified, make sure not to overwrite a file!
189 std::cerr << ProgName << ": error opening '" << OutputFilename
190 << "': file exists!\n"
191 << "Use -f command line argument to force output\n";
195 // Make sure that the Out file gets unlinked from the disk if we get a
197 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
200 raw_ostream *Out = new raw_fd_ostream(OutputFilename.c_str(), Binary, error);
201 if (!error.empty()) {
202 std::cerr << error << '\n';
210 // main - Entry point for the llc compiler.
212 int main(int argc, char **argv) {
213 sys::PrintStackTraceOnErrorSignal();
214 PrettyStackTraceProgram X(argc, argv);
215 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
216 cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
218 InitializeAllTargets();
219 InitializeAllAsmPrinters();
221 // Load the module to be compiled...
222 std::string ErrorMessage;
223 std::auto_ptr<Module> M;
225 std::auto_ptr<MemoryBuffer> Buffer(
226 MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage));
228 M.reset(ParseBitcodeFile(Buffer.get(), &ErrorMessage));
230 std::cerr << argv[0] << ": bitcode didn't read correctly.\n";
231 std::cerr << "Reason: " << ErrorMessage << "\n";
234 Module &mod = *M.get();
236 // If we are supposed to override the target triple, do so now.
237 if (!TargetTriple.empty())
238 mod.setTargetTriple(TargetTriple);
240 // Allocate target machine. First, check whether the user has
241 // explicitly specified an architecture to compile for.
244 MArch = TargetMachineRegistry::getClosestStaticTargetForModule(mod, Err);
246 std::cerr << argv[0] << ": error auto-selecting target for module '"
247 << Err << "'. Please use the -march option to explicitly "
248 << "pick a target.\n";
253 // Package up features to be passed to target/subtarget
254 std::string FeaturesStr;
255 if (MCPU.size() || MAttrs.size()) {
256 SubtargetFeatures Features;
257 Features.setCPU(MCPU);
258 for (unsigned i = 0; i != MAttrs.size(); ++i)
259 Features.AddFeature(MAttrs[i]);
260 FeaturesStr = Features.getString();
263 std::auto_ptr<TargetMachine> target(MArch->CtorFn(mod, FeaturesStr));
264 assert(target.get() && "Could not allocate target machine!");
265 TargetMachine &Target = *target.get();
267 // Figure out where we are going to send the output...
268 raw_ostream *Out = GetOutputStream(argv[0]);
269 if (Out == 0) return 1;
271 CodeGenOpt::Level OLvl = CodeGenOpt::Default;
274 std::cerr << argv[0] << ": invalid optimization level.\n";
277 case '0': OLvl = CodeGenOpt::None; break;
279 case '2': OLvl = CodeGenOpt::Default; break;
280 case '3': OLvl = CodeGenOpt::Aggressive; break;
283 // If this target requires addPassesToEmitWholeFile, do it now. This is
284 // used by strange things like the C backend.
285 if (Target.WantsWholeFile()) {
287 PM.add(new TargetData(*Target.getTargetData()));
289 PM.add(createVerifierPass());
291 // Ask the target to add backend passes as necessary.
292 if (Target.addPassesToEmitWholeFile(PM, *Out, FileType, OLvl)) {
293 std::cerr << argv[0] << ": target does not support generation of this"
295 if (Out != &outs()) delete Out;
296 // And the Out file is empty and useless, so remove it now.
297 sys::Path(OutputFilename).eraseFromDisk();
302 // Build up all of the passes that we want to do to the module.
303 ExistingModuleProvider Provider(M.release());
304 FunctionPassManager Passes(&Provider);
305 Passes.add(new TargetData(*Target.getTargetData()));
309 Passes.add(createVerifierPass());
312 // Ask the target to add backend passes as necessary.
313 MachineCodeEmitter *MCE = 0;
315 // Override default to generate verbose assembly.
316 Target.setAsmVerbosityDefault(true);
318 switch (Target.addPassesToEmitFile(Passes, *Out, FileType, OLvl)) {
320 assert(0 && "Invalid file model!");
322 case FileModel::Error:
323 std::cerr << argv[0] << ": target does not support generation of this"
325 if (Out != &outs()) delete Out;
326 // And the Out file is empty and useless, so remove it now.
327 sys::Path(OutputFilename).eraseFromDisk();
329 case FileModel::AsmFile:
331 case FileModel::MachOFile:
332 MCE = AddMachOWriter(Passes, *Out, Target);
334 case FileModel::ElfFile:
335 MCE = AddELFWriter(Passes, *Out, Target);
339 if (Target.addPassesToEmitFileFinish(Passes, MCE, OLvl)) {
340 std::cerr << argv[0] << ": target does not support generation of this"
342 if (Out != &outs()) delete Out;
343 // And the Out file is empty and useless, so remove it now.
344 sys::Path(OutputFilename).eraseFromDisk();
348 Passes.doInitialization();
350 // Run our queue of passes all at once now, efficiently.
351 // TODO: this could lazily stream functions out of the module.
352 for (Module::iterator I = mod.begin(), E = mod.end(); I != E; ++I)
353 if (!I->isDeclaration()) {
355 I->addFnAttr(Attribute::NoRedZone);
356 if (NoImplicitFloats)
357 I->addFnAttr(Attribute::NoImplicitFloat);
361 Passes.doFinalization();
364 // Delete the ostream if it's not a stdout stream
365 if (Out != &outs()) delete Out;