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 bytecode.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/Bytecode/Reader.h"
17 #include "llvm/Target/SubtargetFeature.h"
18 #include "llvm/Target/TargetMachine.h"
19 #include "llvm/Target/TargetMachineRegistry.h"
20 #include "llvm/Transforms/Scalar.h"
21 #include "llvm/Module.h"
22 #include "llvm/PassManager.h"
23 #include "llvm/Pass.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/PluginLoader.h"
26 #include "llvm/Support/PassNameParser.h"
27 #include "llvm/Analysis/Verifier.h"
28 #include "llvm/System/Signals.h"
29 #include "llvm/Config/config.h"
36 // General options for llc. Other pass-specific options are specified
37 // within the corresponding llc passes, and target-specific options
38 // and back-end code generation options are specified with the target machine.
40 static cl::opt<std::string>
41 InputFilename(cl::Positional, cl::desc("<input bytecode>"), cl::init("-"));
43 static cl::opt<std::string>
44 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
46 static cl::opt<bool> Force("f", cl::desc("Overwrite output files"));
48 static cl::opt<bool> Fast("fast",
49 cl::desc("Generate code quickly, potentially sacrificing code quality"));
51 static cl::opt<std::string>
52 TargetTriple("triple", cl::desc("Override target triple for module"));
54 static cl::opt<const TargetMachineRegistry::Entry*, false, TargetNameParser>
55 MArch("march", cl::desc("Architecture to generate code for:"));
57 static cl::opt<std::string>
59 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
60 cl::value_desc("cpu-name"),
63 static cl::list<std::string>
66 cl::desc("Target specific attributes (-mattr=help for details)"),
67 cl::value_desc("a1,+a2,-a3,..."));
69 cl::opt<TargetMachine::CodeGenFileType>
70 FileType("filetype", cl::init(TargetMachine::AssemblyFile),
71 cl::desc("Choose a file type (not all types are supported by all targets):"),
73 clEnumValN(TargetMachine::AssemblyFile, "asm",
74 " Emit an assembly ('.s') file"),
75 clEnumValN(TargetMachine::ObjectFile, "obj",
76 " Emit a native object ('.o') file [experimental]"),
77 clEnumValN(TargetMachine::DynamicLibrary, "dynlib",
78 " Emit a native dynamic library ('.so') file"),
81 // The LLCPassList is populated with passes that were registered using
82 // PassInfo::LLC by the FilteredPassNameParser:
83 cl::list<const PassInfo*, bool, FilteredPassNameParser<PassInfo::LLC> >
84 LLCPassList(cl::desc("Passes Available"));
86 cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
87 cl::desc("Do not verify input module"));
90 // GetFileNameRoot - Helper function to get the basename of a filename.
91 static inline std::string
92 GetFileNameRoot(const std::string &InputFilename) {
93 std::string IFN = InputFilename;
94 std::string outputFilename;
95 int Len = IFN.length();
97 IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
98 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
100 outputFilename = IFN;
102 return outputFilename;
106 // main - Entry point for the llc compiler.
108 int main(int argc, char **argv) {
110 cl::ParseCommandLineOptions(argc, argv, " llvm system compiler\n");
111 sys::PrintStackTraceOnErrorSignal();
113 // Load the module to be compiled...
114 std::auto_ptr<Module> M(ParseBytecodeFile(InputFilename));
116 std::cerr << argv[0] << ": bytecode didn't read correctly.\n";
119 Module &mod = *M.get();
121 // If we are supposed to override the target triple, do so now.
122 if (!TargetTriple.empty())
123 mod.setTargetTriple(TargetTriple);
125 // Allocate target machine. First, check whether the user has
126 // explicitly specified an architecture to compile for.
127 TargetMachine* (*TargetMachineAllocator)(const Module&,
128 IntrinsicLowering *) = 0;
131 MArch = TargetMachineRegistry::getClosestStaticTargetForModule(mod, Err);
133 std::cerr << argv[0] << ": error auto-selecting target for module '"
134 << Err << "'. Please use the -march option to explicitly "
135 << "pick a target.\n";
140 // Package up features to be passed to target/subtarget
141 std::string FeaturesStr;
142 if (MCPU.size() || MAttrs.size()) {
143 SubtargetFeatures Features;
144 Features.setCPU(MCPU);
145 for (unsigned i = 0; i != MAttrs.size(); ++i)
146 Features.AddFeature(MAttrs[i]);
147 FeaturesStr = Features.getString();
150 std::auto_ptr<TargetMachine> target(MArch->CtorFn(mod, 0, FeaturesStr));
151 assert(target.get() && "Could not allocate target machine!");
152 TargetMachine &Target = *target.get();
153 const TargetData &TD = Target.getTargetData();
155 // Build up all of the passes that we want to do to the module...
157 Passes.add(new TargetData(TD));
159 // Create a new pass for each one specified on the command line
160 for (unsigned i = 0; i < LLCPassList.size(); ++i) {
161 const PassInfo *aPass = LLCPassList[i];
163 if (aPass->getNormalCtor()) {
164 Pass *P = aPass->getNormalCtor()();
167 std::cerr << argv[0] << ": cannot create pass: "
168 << aPass->getPassName() << "\n";
174 Passes.add(createVerifierPass());
177 // Figure out where we are going to send the output...
178 std::ostream *Out = 0;
179 if (OutputFilename != "") {
180 if (OutputFilename != "-") {
181 // Specified an output filename?
182 if (!Force && std::ifstream(OutputFilename.c_str())) {
183 // If force is not specified, make sure not to overwrite a file!
184 std::cerr << argv[0] << ": error opening '" << OutputFilename
185 << "': file exists!\n"
186 << "Use -f command line argument to force output\n";
189 Out = new std::ofstream(OutputFilename.c_str());
191 // Make sure that the Out file gets unlinked from the disk if we get a
193 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
198 if (InputFilename == "-") {
199 OutputFilename = "-";
202 OutputFilename = GetFileNameRoot(InputFilename);
205 case TargetMachine::AssemblyFile:
206 if (MArch->Name[0] != 'c' || MArch->Name[1] != 0) // not CBE
207 OutputFilename += ".s";
209 OutputFilename += ".cbe.c";
211 case TargetMachine::ObjectFile:
212 OutputFilename += ".o";
214 case TargetMachine::DynamicLibrary:
215 OutputFilename += LTDL_SHLIB_EXT;
219 if (!Force && std::ifstream(OutputFilename.c_str())) {
220 // If force is not specified, make sure not to overwrite a file!
221 std::cerr << argv[0] << ": error opening '" << OutputFilename
222 << "': file exists!\n"
223 << "Use -f command line argument to force output\n";
227 Out = new std::ofstream(OutputFilename.c_str());
229 std::cerr << argv[0] << ": error opening " << OutputFilename << "!\n";
234 // Make sure that the Out file gets unlinked from the disk if we get a
236 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
240 // Ask the target to add backend passes as necessary.
241 if (Target.addPassesToEmitFile(Passes, *Out, FileType, Fast)) {
242 std::cerr << argv[0] << ": target '" << Target.getName()
243 << "' does not support generation of this file type!\n";
244 if (Out != &std::cout) delete Out;
245 // And the Out file is empty and useless, so remove it now.
246 std::remove(OutputFilename.c_str());
249 // Run our queue of passes all at once now, efficiently.
250 Passes.run(*M.get());
253 // Delete the ostream if it's not a stdout stream
254 if (Out != &std::cout) delete Out;
257 } catch (const std::string& msg) {
258 std::cerr << argv[0] << ": " << msg << "\n";
260 std::cerr << argv[0] << ": Unexpected unknown exception occurred.\n";