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/Target/SubtargetFeature.h"
20 #include "llvm/Target/TargetData.h"
21 #include "llvm/Target/TargetMachine.h"
22 #include "llvm/Target/TargetMachineRegistry.h"
23 #include "llvm/Transforms/Scalar.h"
24 #include "llvm/Module.h"
25 #include "llvm/ModuleProvider.h"
26 #include "llvm/PassManager.h"
27 #include "llvm/Pass.h"
28 #include "llvm/Support/CommandLine.h"
29 #include "llvm/Support/ManagedStatic.h"
30 #include "llvm/Support/MemoryBuffer.h"
31 #include "llvm/Support/PluginLoader.h"
32 #include "llvm/Support/FileUtilities.h"
33 #include "llvm/Analysis/Verifier.h"
34 #include "llvm/System/Signals.h"
35 #include "llvm/Config/config.h"
36 #include "llvm/LinkAllVMCore.h"
42 // General options for llc. Other pass-specific options are specified
43 // within the corresponding llc passes, and target-specific options
44 // and back-end code generation options are specified with the target machine.
46 static cl::opt<std::string>
47 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
49 static cl::opt<std::string>
50 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
52 static cl::opt<bool> Force("f", cl::desc("Overwrite output files"));
54 static cl::opt<bool> Fast("fast",
55 cl::desc("Generate code quickly, potentially sacrificing code quality"));
57 static cl::opt<std::string>
58 TargetTriple("mtriple", cl::desc("Override target triple for module"));
60 static cl::opt<const TargetMachineRegistry::entry*, false,
61 TargetMachineRegistry::Parser>
62 MArch("march", cl::desc("Architecture to generate code for:"));
64 static cl::opt<std::string>
66 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
67 cl::value_desc("cpu-name"),
70 static cl::list<std::string>
73 cl::desc("Target specific attributes (-mattr=help for details)"),
74 cl::value_desc("a1,+a2,-a3,..."));
76 cl::opt<TargetMachine::CodeGenFileType>
77 FileType("filetype", cl::init(TargetMachine::AssemblyFile),
78 cl::desc("Choose a file type (not all types are supported by all targets):"),
80 clEnumValN(TargetMachine::AssemblyFile, "asm",
81 " Emit an assembly ('.s') file"),
82 clEnumValN(TargetMachine::ObjectFile, "obj",
83 " Emit a native object ('.o') file [experimental]"),
84 clEnumValN(TargetMachine::DynamicLibrary, "dynlib",
85 " Emit a native dynamic library ('.so') file"
89 cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
90 cl::desc("Do not verify input module"));
93 // GetFileNameRoot - Helper function to get the basename of a filename.
94 static inline std::string
95 GetFileNameRoot(const std::string &InputFilename) {
96 std::string IFN = InputFilename;
97 std::string outputFilename;
98 int Len = IFN.length();
100 IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
101 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
103 outputFilename = IFN;
105 return outputFilename;
108 static std::ostream *GetOutputStream(const char *ProgName) {
109 if (OutputFilename != "") {
110 if (OutputFilename == "-")
113 // Specified an output filename?
114 if (!Force && std::ifstream(OutputFilename.c_str())) {
115 // If force is not specified, make sure not to overwrite a file!
116 std::cerr << ProgName << ": error opening '" << OutputFilename
117 << "': file exists!\n"
118 << "Use -f command line argument to force output\n";
121 // Make sure that the Out file gets unlinked from the disk if we get a
123 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
125 return new std::ofstream(OutputFilename.c_str());
128 if (InputFilename == "-") {
129 OutputFilename = "-";
133 OutputFilename = GetFileNameRoot(InputFilename);
136 case TargetMachine::AssemblyFile:
137 if (MArch->Name[0] == 'c') {
138 if (MArch->Name[1] == 0)
139 OutputFilename += ".cbe.c";
140 else if (MArch->Name[1] == 'p' && MArch->Name[2] == 'p')
141 OutputFilename += ".cpp";
143 OutputFilename += ".s";
145 OutputFilename += ".s";
147 case TargetMachine::ObjectFile:
148 OutputFilename += ".o";
150 case TargetMachine::DynamicLibrary:
151 OutputFilename += LTDL_SHLIB_EXT;
155 if (!Force && std::ifstream(OutputFilename.c_str())) {
156 // If force is not specified, make sure not to overwrite a file!
157 std::cerr << ProgName << ": error opening '" << OutputFilename
158 << "': file exists!\n"
159 << "Use -f command line argument to force output\n";
163 // Make sure that the Out file gets unlinked from the disk if we get a
165 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
167 std::ostream *Out = new std::ofstream(OutputFilename.c_str());
169 std::cerr << ProgName << ": error opening " << OutputFilename << "!\n";
177 // main - Entry point for the llc compiler.
179 int main(int argc, char **argv) {
180 llvm_shutdown_obj X; // Call llvm_shutdown() on exit.
181 cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
182 sys::PrintStackTraceOnErrorSignal();
184 // Load the module to be compiled...
185 std::string ErrorMessage;
186 std::auto_ptr<Module> M;
188 std::auto_ptr<MemoryBuffer> Buffer(
189 MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage));
191 M.reset(ParseBitcodeFile(Buffer.get(), &ErrorMessage));
193 std::cerr << argv[0] << ": bitcode didn't read correctly.\n";
194 std::cerr << "Reason: " << ErrorMessage << "\n";
197 Module &mod = *M.get();
199 // If we are supposed to override the target triple, do so now.
200 if (!TargetTriple.empty())
201 mod.setTargetTriple(TargetTriple);
203 // Allocate target machine. First, check whether the user has
204 // explicitly specified an architecture to compile for.
207 MArch = TargetMachineRegistry::getClosestStaticTargetForModule(mod, Err);
209 std::cerr << argv[0] << ": error auto-selecting target for module '"
210 << Err << "'. Please use the -march option to explicitly "
211 << "pick a target.\n";
216 // Package up features to be passed to target/subtarget
217 std::string FeaturesStr;
218 if (MCPU.size() || MAttrs.size()) {
219 SubtargetFeatures Features;
220 Features.setCPU(MCPU);
221 for (unsigned i = 0; i != MAttrs.size(); ++i)
222 Features.AddFeature(MAttrs[i]);
223 FeaturesStr = Features.getString();
226 std::auto_ptr<TargetMachine> target(MArch->CtorFn(mod, FeaturesStr));
227 assert(target.get() && "Could not allocate target machine!");
228 TargetMachine &Target = *target.get();
230 // Figure out where we are going to send the output...
231 std::ostream *Out = GetOutputStream(argv[0]);
232 if (Out == 0) return 1;
234 // If this target requires addPassesToEmitWholeFile, do it now. This is
235 // used by strange things like the C backend.
236 if (Target.WantsWholeFile()) {
238 PM.add(new TargetData(*Target.getTargetData()));
240 PM.add(createVerifierPass());
242 // Ask the target to add backend passes as necessary.
243 if (Target.addPassesToEmitWholeFile(PM, *Out, FileType, Fast)) {
244 std::cerr << argv[0] << ": target does not support generation of this"
246 if (Out != &std::cout) delete Out;
247 // And the Out file is empty and useless, so remove it now.
248 sys::Path(OutputFilename).eraseFromDisk();
253 // Build up all of the passes that we want to do to the module.
254 ExistingModuleProvider Provider(M.release());
255 FunctionPassManager Passes(&Provider);
256 Passes.add(new TargetData(*Target.getTargetData()));
260 Passes.add(createVerifierPass());
263 // Ask the target to add backend passes as necessary.
264 MachineCodeEmitter *MCE = 0;
266 switch (Target.addPassesToEmitFile(Passes, *Out, FileType, Fast)) {
268 assert(0 && "Invalid file model!");
270 case FileModel::Error:
271 std::cerr << argv[0] << ": target does not support generation of this"
273 if (Out != &std::cout) delete Out;
274 // And the Out file is empty and useless, so remove it now.
275 sys::Path(OutputFilename).eraseFromDisk();
277 case FileModel::AsmFile:
279 case FileModel::MachOFile:
280 MCE = AddMachOWriter(Passes, *Out, Target);
282 case FileModel::ElfFile:
283 MCE = AddELFWriter(Passes, *Out, Target);
287 if (Target.addPassesToEmitFileFinish(Passes, MCE, Fast)) {
288 std::cerr << argv[0] << ": target does not support generation of this"
290 if (Out != &std::cout) delete Out;
291 // And the Out file is empty and useless, so remove it now.
292 sys::Path(OutputFilename).eraseFromDisk();
296 Passes.doInitialization();
298 // Run our queue of passes all at once now, efficiently.
299 // TODO: this could lazily stream functions out of the module.
300 for (Module::iterator I = mod.begin(), E = mod.end(); I != E; ++I)
301 if (!I->isDeclaration())
304 Passes.doFinalization();
307 // Delete the ostream if it's not a stdout stream
308 if (Out != &std::cout) delete Out;