1 //===- llvm-extract.cpp - LLVM function extraction utility ----------------===//
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 utility changes the input module to only contain a single function,
11 // which is primarily used for debugging transformations.
13 //===----------------------------------------------------------------------===//
15 #include "llvm/Module.h"
16 #include "llvm/PassManager.h"
17 #include "llvm/Bitcode/ReaderWriter.h"
18 #include "llvm/Transforms/IPO.h"
19 #include "llvm/Target/TargetData.h"
20 #include "llvm/Support/CommandLine.h"
21 #include "llvm/Support/ManagedStatic.h"
22 #include "llvm/Support/MemoryBuffer.h"
23 #include "llvm/System/Signals.h"
29 // InputFilename - The filename to read from.
30 static cl::opt<std::string>
31 InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
32 cl::init("-"), cl::value_desc("filename"));
34 static cl::opt<std::string>
35 OutputFilename("o", cl::desc("Specify output filename"),
36 cl::value_desc("filename"), cl::init("-"));
39 Force("f", cl::desc("Overwrite output files"));
42 DeleteFn("delete", cl::desc("Delete specified function from Module"));
46 cl::desc("Turn external linkage for callees of function to delete"));
48 // ExtractFunc - The function to extract from the module... defaults to main.
49 static cl::opt<std::string>
50 ExtractFunc("func", cl::desc("Specify function to extract"), cl::init("main"),
51 cl::value_desc("function"));
53 int main(int argc, char **argv) {
54 llvm_shutdown_obj X; // Call llvm_shutdown() on exit.
55 cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");
56 sys::PrintStackTraceOnErrorSignal();
58 std::auto_ptr<Module> M;
60 MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(InputFilename);
62 cerr << argv[0] << ": Error reading file '" + InputFilename + "'\n";
65 M.reset(ParseBitcodeFile(Buffer));
70 cerr << argv[0] << ": bitcode didn't read correctly.\n";
74 // Figure out which function we should extract
75 Function *F = M.get()->getFunction(ExtractFunc);
77 cerr << argv[0] << ": program doesn't contain function named '"
78 << ExtractFunc << "'!\n";
82 // In addition to deleting all other functions, we also want to spiff it
83 // up a little bit. Do this now.
85 Passes.add(new TargetData(M.get())); // Use correct TargetData
86 // Either isolate the function or delete it from the Module
87 Passes.add(createFunctionExtractionPass(F, DeleteFn, Relink));
89 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
90 Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
91 Passes.add(createStripDeadPrototypesPass()); // Remove dead func decls
93 std::ostream *Out = 0;
95 if (OutputFilename != "-") { // Not stdout?
96 if (!Force && std::ifstream(OutputFilename.c_str())) {
97 // If force is not specified, make sure not to overwrite a file!
98 cerr << argv[0] << ": error opening '" << OutputFilename
99 << "': file exists!\n"
100 << "Use -f command line argument to force output\n";
103 std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
105 Out = new std::ofstream(OutputFilename.c_str(), io_mode);
106 } else { // Specified stdout
107 // FIXME: cout is not binary!
111 Passes.add(CreateBitcodeWriterPass(*Out));
112 Passes.run(*M.get());
114 if (Out != &std::cout)