1 //===-- llc.cpp - Implement the LLVM Native Code Generator ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source 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, TargetNameParser>
61 MArch("march", cl::desc("Architecture to generate code for:"));
63 static cl::opt<std::string>
65 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
66 cl::value_desc("cpu-name"),
69 static cl::list<std::string>
72 cl::desc("Target specific attributes (-mattr=help for details)"),
73 cl::value_desc("a1,+a2,-a3,..."));
75 cl::opt<TargetMachine::CodeGenFileType>
76 FileType("filetype", cl::init(TargetMachine::AssemblyFile),
77 cl::desc("Choose a file type (not all types are supported by all targets):"),
79 clEnumValN(TargetMachine::AssemblyFile, "asm",
80 " Emit an assembly ('.s') file"),
81 clEnumValN(TargetMachine::ObjectFile, "obj",
82 " Emit a native object ('.o') file [experimental]"),
83 clEnumValN(TargetMachine::DynamicLibrary, "dynlib",
84 " Emit a native dynamic library ('.so') file"
88 cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
89 cl::desc("Do not verify input module"));
92 // GetFileNameRoot - Helper function to get the basename of a filename.
93 static inline std::string
94 GetFileNameRoot(const std::string &InputFilename) {
95 std::string IFN = InputFilename;
96 std::string outputFilename;
97 int Len = IFN.length();
99 IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
100 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
102 outputFilename = IFN;
104 return outputFilename;
107 static std::ostream *GetOutputStream(const char *ProgName) {
108 if (OutputFilename != "") {
109 if (OutputFilename == "-")
112 // Specified an output filename?
113 if (!Force && std::ifstream(OutputFilename.c_str())) {
114 // If force is not specified, make sure not to overwrite a file!
115 std::cerr << ProgName << ": error opening '" << OutputFilename
116 << "': file exists!\n"
117 << "Use -f command line argument to force output\n";
120 // Make sure that the Out file gets unlinked from the disk if we get a
122 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
124 return new std::ofstream(OutputFilename.c_str());
127 if (InputFilename == "-") {
128 OutputFilename = "-";
132 OutputFilename = GetFileNameRoot(InputFilename);
135 case TargetMachine::AssemblyFile:
136 if (MArch->Name[0] != 'c' || MArch->Name[1] != 0) // not CBE
137 OutputFilename += ".s";
139 OutputFilename += ".cbe.c";
141 case TargetMachine::ObjectFile:
142 OutputFilename += ".o";
144 case TargetMachine::DynamicLibrary:
145 OutputFilename += LTDL_SHLIB_EXT;
149 if (!Force && std::ifstream(OutputFilename.c_str())) {
150 // If force is not specified, make sure not to overwrite a file!
151 std::cerr << ProgName << ": error opening '" << OutputFilename
152 << "': file exists!\n"
153 << "Use -f command line argument to force output\n";
157 // Make sure that the Out file gets unlinked from the disk if we get a
159 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
161 std::ostream *Out = new std::ofstream(OutputFilename.c_str());
163 std::cerr << ProgName << ": error opening " << OutputFilename << "!\n";
171 // main - Entry point for the llc compiler.
173 int main(int argc, char **argv) {
174 llvm_shutdown_obj X; // Call llvm_shutdown() on exit.
175 cl::ParseCommandLineOptions(argc, argv, " llvm system compiler\n");
176 sys::PrintStackTraceOnErrorSignal();
178 // Load the module to be compiled...
179 std::string ErrorMessage;
180 std::auto_ptr<Module> M;
182 std::auto_ptr<MemoryBuffer> Buffer(
183 MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage));
185 M.reset(ParseBitcodeFile(Buffer.get(), &ErrorMessage));
187 std::cerr << argv[0] << ": bitcode didn't read correctly.\n";
188 std::cerr << "Reason: " << ErrorMessage << "\n";
191 Module &mod = *M.get();
193 // If we are supposed to override the target triple, do so now.
194 if (!TargetTriple.empty())
195 mod.setTargetTriple(TargetTriple);
197 // Allocate target machine. First, check whether the user has
198 // explicitly specified an architecture to compile for.
201 MArch = TargetMachineRegistry::getClosestStaticTargetForModule(mod, Err);
203 std::cerr << argv[0] << ": error auto-selecting target for module '"
204 << Err << "'. Please use the -march option to explicitly "
205 << "pick a target.\n";
210 // Package up features to be passed to target/subtarget
211 std::string FeaturesStr;
212 if (MCPU.size() || MAttrs.size()) {
213 SubtargetFeatures Features;
214 Features.setCPU(MCPU);
215 for (unsigned i = 0; i != MAttrs.size(); ++i)
216 Features.AddFeature(MAttrs[i]);
217 FeaturesStr = Features.getString();
220 std::auto_ptr<TargetMachine> target(MArch->CtorFn(mod, FeaturesStr));
221 assert(target.get() && "Could not allocate target machine!");
222 TargetMachine &Target = *target.get();
224 // Figure out where we are going to send the output...
225 std::ostream *Out = GetOutputStream(argv[0]);
226 if (Out == 0) return 1;
228 // If this target requires addPassesToEmitWholeFile, do it now. This is
229 // used by strange things like the C backend.
230 if (Target.WantsWholeFile()) {
232 PM.add(new TargetData(*Target.getTargetData()));
234 PM.add(createVerifierPass());
236 // Ask the target to add backend passes as necessary.
237 if (Target.addPassesToEmitWholeFile(PM, *Out, FileType, Fast)) {
238 std::cerr << argv[0] << ": target does not support generation of this"
240 if (Out != &std::cout) delete Out;
241 // And the Out file is empty and useless, so remove it now.
242 sys::Path(OutputFilename).eraseFromDisk();
247 // Build up all of the passes that we want to do to the module.
248 FunctionPassManager Passes(new ExistingModuleProvider(M.get()));
249 Passes.add(new TargetData(*Target.getTargetData()));
253 Passes.add(createVerifierPass());
256 // Ask the target to add backend passes as necessary.
257 MachineCodeEmitter *MCE = 0;
259 switch (Target.addPassesToEmitFile(Passes, *Out, FileType, Fast)) {
261 assert(0 && "Invalid file model!");
263 case FileModel::Error:
264 std::cerr << argv[0] << ": target does not support generation of this"
266 if (Out != &std::cout) delete Out;
267 // And the Out file is empty and useless, so remove it now.
268 sys::Path(OutputFilename).eraseFromDisk();
270 case FileModel::AsmFile:
272 case FileModel::MachOFile:
273 MCE = AddMachOWriter(Passes, *Out, Target);
275 case FileModel::ElfFile:
276 MCE = AddELFWriter(Passes, *Out, Target);
280 if (Target.addPassesToEmitFileFinish(Passes, MCE, Fast)) {
281 std::cerr << argv[0] << ": target does not support generation of this"
283 if (Out != &std::cout) delete Out;
284 // And the Out file is empty and useless, so remove it now.
285 sys::Path(OutputFilename).eraseFromDisk();
289 Passes.doInitialization();
291 // Run our queue of passes all at once now, efficiently.
292 // TODO: this could lazily stream functions out of the module.
293 for (Module::iterator I = mod.begin(), E = mod.end(); I != E; ++I)
294 if (!I->isDeclaration())
297 Passes.doFinalization();
300 // Delete the ostream if it's not a stdout stream
301 if (Out != &std::cout) delete Out;