1 //===- llvm-extract.cpp - LLVM function extraction utility ----------------===//
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 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/Bytecode/Reader.h"
19 #include "llvm/Bytecode/WriteBytecodePass.h"
20 #include "llvm/Transforms/IPO.h"
21 #include "llvm/Target/TargetData.h"
22 #include "llvm/Support/CommandLine.h"
23 #include "llvm/Support/Compressor.h"
24 #include "llvm/Support/ManagedStatic.h"
25 #include "llvm/Support/MemoryBuffer.h"
26 #include "llvm/Support/Streams.h"
27 #include "llvm/System/Signals.h"
33 cl::opt<bool> Bitcode("bitcode");
35 // InputFilename - The filename to read from.
36 static cl::opt<std::string>
37 InputFilename(cl::Positional, cl::desc("<input bytecode file>"),
38 cl::init("-"), cl::value_desc("filename"));
40 static cl::opt<std::string>
41 OutputFilename("o", cl::desc("Specify output filename"),
42 cl::value_desc("filename"), cl::init("-"));
45 Force("f", cl::desc("Overwrite output files"));
48 DeleteFn("delete", cl::desc("Delete specified function from Module"));
52 cl::desc("Turn external linkage for callees of function to delete"));
54 // ExtractFunc - The function to extract from the module... defaults to main.
55 static cl::opt<std::string>
56 ExtractFunc("func", cl::desc("Specify function to extract"), cl::init("main"),
57 cl::value_desc("function"));
59 int main(int argc, char **argv) {
60 llvm_shutdown_obj X; // Call llvm_shutdown() on exit.
61 cl::ParseCommandLineOptions(argc, argv, " llvm extractor\n");
62 sys::PrintStackTraceOnErrorSignal();
64 std::auto_ptr<Module> M;
67 MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(&InputFilename[0],
68 InputFilename.size());
70 cerr << "Error reading file '" + InputFilename + "'";
73 M.reset(ParseBitcodeFile(Buffer));
77 M.reset(ParseBytecodeFile(InputFilename,
78 Compressor::decompressToNewBuffer));
82 cerr << argv[0] << ": bytecode didn't read correctly.\n";
86 // Figure out which function we should extract
87 Function *F = M.get()->getFunction(ExtractFunc);
89 cerr << argv[0] << ": program doesn't contain function named '"
90 << ExtractFunc << "'!\n";
94 // In addition to deleting all other functions, we also want to spiff it
95 // up a little bit. Do this now.
97 Passes.add(new TargetData(M.get())); // Use correct TargetData
98 // Either isolate the function or delete it from the Module
99 Passes.add(createFunctionExtractionPass(F, DeleteFn, Relink));
101 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
102 Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
103 Passes.add(createStripDeadPrototypesPass()); // Remove dead func decls
105 std::ostream *Out = 0;
107 if (OutputFilename != "-") { // Not stdout?
108 if (!Force && std::ifstream(OutputFilename.c_str())) {
109 // If force is not specified, make sure not to overwrite a file!
110 cerr << argv[0] << ": error opening '" << OutputFilename
111 << "': file exists!\n"
112 << "Use -f command line argument to force output\n";
115 std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
117 Out = new std::ofstream(OutputFilename.c_str(), io_mode);
118 } else { // Specified stdout
119 // FIXME: cout is not binary!
125 Passes.add(CreateBitcodeWriterPass(*Out));
127 Passes.add(new WriteBytecodePass(&L)); // Write bytecode to file...
128 Passes.run(*M.get());
130 if (Out != &std::cout)