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/ManagedStatic.h"
31 #include "llvm/Support/MemoryBuffer.h"
32 #include "llvm/Support/PluginLoader.h"
33 #include "llvm/Support/FileUtilities.h"
34 #include "llvm/Support/raw_ostream.h"
35 #include "llvm/Analysis/Verifier.h"
36 #include "llvm/System/Signals.h"
37 #include "llvm/Config/config.h"
38 #include "llvm/LinkAllVMCore.h"
44 // General options for llc. Other pass-specific options are specified
45 // within the corresponding llc passes, and target-specific options
46 // and back-end code generation options are specified with the target machine.
48 static cl::opt<std::string>
49 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
51 static cl::opt<std::string>
52 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
54 static cl::opt<bool> Force("f", cl::desc("Overwrite output files"));
56 static cl::opt<bool> Fast("fast",
57 cl::desc("Generate code quickly, potentially sacrificing code quality"));
59 static cl::opt<std::string>
60 TargetTriple("mtriple", cl::desc("Override target triple for module"));
62 static cl::opt<const TargetMachineRegistry::entry*, false,
63 TargetMachineRegistry::Parser>
64 MArch("march", cl::desc("Architecture to generate code for:"));
66 static cl::opt<std::string>
68 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
69 cl::value_desc("cpu-name"),
72 static cl::list<std::string>
75 cl::desc("Target specific attributes (-mattr=help for details)"),
76 cl::value_desc("a1,+a2,-a3,..."));
78 cl::opt<TargetMachine::CodeGenFileType>
79 FileType("filetype", cl::init(TargetMachine::AssemblyFile),
80 cl::desc("Choose a file type (not all types are supported by all targets):"),
82 clEnumValN(TargetMachine::AssemblyFile, "asm",
83 " Emit an assembly ('.s') file"),
84 clEnumValN(TargetMachine::ObjectFile, "obj",
85 " Emit a native object ('.o') file [experimental]"),
86 clEnumValN(TargetMachine::DynamicLibrary, "dynlib",
87 " Emit a native dynamic library ('.so') file"
91 cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
92 cl::desc("Do not verify input module"));
95 // GetFileNameRoot - Helper function to get the basename of a filename.
96 static inline std::string
97 GetFileNameRoot(const std::string &InputFilename) {
98 std::string IFN = InputFilename;
99 std::string outputFilename;
100 int Len = IFN.length();
102 IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
103 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
105 outputFilename = IFN;
107 return outputFilename;
110 static raw_ostream *GetOutputStream(const char *ProgName) {
111 if (OutputFilename != "") {
112 if (OutputFilename == "-")
115 // Specified an output filename?
116 if (!Force && std::ifstream(OutputFilename.c_str())) {
117 // If force is not specified, make sure not to overwrite a file!
118 std::cerr << ProgName << ": error opening '" << OutputFilename
119 << "': file exists!\n"
120 << "Use -f command line argument to force output\n";
123 // Make sure that the Out file gets unlinked from the disk if we get a
125 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
128 return new raw_fd_ostream(OutputFilename.c_str(), error);
131 if (InputFilename == "-") {
132 OutputFilename = "-";
136 OutputFilename = GetFileNameRoot(InputFilename);
139 case TargetMachine::AssemblyFile:
140 if (MArch->Name[0] == 'c') {
141 if (MArch->Name[1] == 0)
142 OutputFilename += ".cbe.c";
143 else if (MArch->Name[1] == 'p' && MArch->Name[2] == 'p')
144 OutputFilename += ".cpp";
146 OutputFilename += ".s";
148 OutputFilename += ".s";
150 case TargetMachine::ObjectFile:
151 OutputFilename += ".o";
153 case TargetMachine::DynamicLibrary:
154 OutputFilename += LTDL_SHLIB_EXT;
158 if (!Force && std::ifstream(OutputFilename.c_str())) {
159 // If force is not specified, make sure not to overwrite a file!
160 std::cerr << ProgName << ": error opening '" << OutputFilename
161 << "': file exists!\n"
162 << "Use -f command line argument to force output\n";
166 // Make sure that the Out file gets unlinked from the disk if we get a
168 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
171 raw_ostream *Out = new raw_fd_ostream(OutputFilename.c_str(), error);
172 if (!error.empty()) {
181 // main - Entry point for the llc compiler.
183 int main(int argc, char **argv) {
184 llvm_shutdown_obj X; // Call llvm_shutdown() on exit.
185 cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
186 sys::PrintStackTraceOnErrorSignal();
188 // Load the module to be compiled...
189 std::string ErrorMessage;
190 std::auto_ptr<Module> M;
192 std::auto_ptr<MemoryBuffer> Buffer(
193 MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage));
195 M.reset(ParseBitcodeFile(Buffer.get(), &ErrorMessage));
197 std::cerr << argv[0] << ": bitcode didn't read correctly.\n";
198 std::cerr << "Reason: " << ErrorMessage << "\n";
201 Module &mod = *M.get();
203 // If we are supposed to override the target triple, do so now.
204 if (!TargetTriple.empty())
205 mod.setTargetTriple(TargetTriple);
207 // Allocate target machine. First, check whether the user has
208 // explicitly specified an architecture to compile for.
211 MArch = TargetMachineRegistry::getClosestStaticTargetForModule(mod, Err);
213 std::cerr << argv[0] << ": error auto-selecting target for module '"
214 << Err << "'. Please use the -march option to explicitly "
215 << "pick a target.\n";
220 // Package up features to be passed to target/subtarget
221 std::string FeaturesStr;
222 if (MCPU.size() || MAttrs.size()) {
223 SubtargetFeatures Features;
224 Features.setCPU(MCPU);
225 for (unsigned i = 0; i != MAttrs.size(); ++i)
226 Features.AddFeature(MAttrs[i]);
227 FeaturesStr = Features.getString();
230 std::auto_ptr<TargetMachine> target(MArch->CtorFn(mod, FeaturesStr));
231 assert(target.get() && "Could not allocate target machine!");
232 TargetMachine &Target = *target.get();
234 // Figure out where we are going to send the output...
235 raw_ostream *Out = GetOutputStream(argv[0]);
236 if (Out == 0) return 1;
238 // If this target requires addPassesToEmitWholeFile, do it now. This is
239 // used by strange things like the C backend.
240 if (Target.WantsWholeFile()) {
242 PM.add(new TargetData(*Target.getTargetData()));
244 PM.add(createVerifierPass());
246 // Ask the target to add backend passes as necessary.
247 if (Target.addPassesToEmitWholeFile(PM, *Out, FileType, Fast)) {
248 std::cerr << argv[0] << ": target does not support generation of this"
250 if (Out != &outs()) delete Out;
251 // And the Out file is empty and useless, so remove it now.
252 sys::Path(OutputFilename).eraseFromDisk();
257 // Build up all of the passes that we want to do to the module.
258 ExistingModuleProvider Provider(M.release());
259 FunctionPassManager Passes(&Provider);
260 Passes.add(new TargetData(*Target.getTargetData()));
264 Passes.add(createVerifierPass());
267 // Ask the target to add backend passes as necessary.
268 MachineCodeEmitter *MCE = 0;
270 switch (Target.addPassesToEmitFile(Passes, *Out, FileType, Fast)) {
272 assert(0 && "Invalid file model!");
274 case FileModel::Error:
275 std::cerr << argv[0] << ": target does not support generation of this"
277 if (Out != &outs()) delete Out;
278 // And the Out file is empty and useless, so remove it now.
279 sys::Path(OutputFilename).eraseFromDisk();
281 case FileModel::AsmFile:
283 case FileModel::MachOFile:
284 MCE = AddMachOWriter(Passes, *Out, Target);
286 case FileModel::ElfFile:
287 MCE = AddELFWriter(Passes, *Out, Target);
291 if (Target.addPassesToEmitFileFinish(Passes, MCE, Fast)) {
292 std::cerr << argv[0] << ": target does not support generation of this"
294 if (Out != &outs()) delete Out;
295 // And the Out file is empty and useless, so remove it now.
296 sys::Path(OutputFilename).eraseFromDisk();
300 Passes.doInitialization();
302 // Run our queue of passes all at once now, efficiently.
303 // TODO: this could lazily stream functions out of the module.
304 for (Module::iterator I = mod.begin(), E = mod.end(); I != E; ++I)
305 if (!I->isDeclaration())
308 Passes.doFinalization();
311 // Delete the ostream if it's not a stdout stream
312 if (Out != &outs()) delete Out;