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 Globals from Module"));
46 cl::desc("Turn external linkage for callees of function to delete"));
48 // ExtractFunc - The function to extract from the module...
49 static cl::opt<std::string>
50 ExtractFunc("func", cl::desc("Specify function to extract"), cl::init(""),
51 cl::value_desc("function"));
53 // ExtractGlobal - The global to extract from the module...
54 static cl::opt<std::string>
55 ExtractGlobal("glob", cl::desc("Specify global to extract"), cl::init(""),
56 cl::value_desc("global"));
58 int main(int argc, char **argv) {
59 llvm_shutdown_obj X; // Call llvm_shutdown() on exit.
60 cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");
61 sys::PrintStackTraceOnErrorSignal();
63 std::auto_ptr<Module> M;
65 MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(InputFilename);
67 cerr << argv[0] << ": Error reading file '" + InputFilename + "'\n";
70 M.reset(ParseBitcodeFile(Buffer));
75 cerr << argv[0] << ": bitcode didn't read correctly.\n";
79 // Figure out which function we should extract
80 GlobalVariable *G = ExtractGlobal.size() ?
81 M.get()->getNamedGlobal(ExtractGlobal) : 0;
83 // Figure out which function we should extract
84 if (!ExtractFunc.size() && !ExtractGlobal.size()) ExtractFunc = "main";
85 Function *F = M.get()->getFunction(ExtractFunc);
87 if (F == 0 && G == 0) {
88 cerr << argv[0] << ": program doesn't contain function named '"
89 << ExtractFunc << "' or a global named '" << ExtractGlobal << "'!\n";
93 // In addition to deleting all other functions, we also want to spiff it
94 // up a little bit. Do this now.
96 Passes.add(new TargetData(M.get())); // Use correct TargetData
97 // Either isolate the function or delete it from the Module
98 std::vector<GlobalValue*> GVs;
99 if (F) GVs.push_back(F);
100 if (G) GVs.push_back(G);
102 Passes.add(createGVExtractionPass(GVs, DeleteFn, Relink));
104 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
105 Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
106 Passes.add(createStripDeadPrototypesPass()); // Remove dead func decls
108 std::ostream *Out = 0;
110 if (OutputFilename != "-") { // Not stdout?
111 if (!Force && std::ifstream(OutputFilename.c_str())) {
112 // If force is not specified, make sure not to overwrite a file!
113 cerr << argv[0] << ": error opening '" << OutputFilename
114 << "': file exists!\n"
115 << "Use -f command line argument to force output\n";
118 std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
120 Out = new std::ofstream(OutputFilename.c_str(), io_mode);
121 } else { // Specified stdout
122 // FIXME: cout is not binary!
126 Passes.add(CreateBitcodeWriterPass(*Out));
127 Passes.run(*M.get());
129 if (Out != &std::cout)