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/LLVMContext.h"
16 #include "llvm/Module.h"
17 #include "llvm/PassManager.h"
18 #include "llvm/Bitcode/ReaderWriter.h"
19 #include "llvm/Transforms/IPO.h"
20 #include "llvm/Target/TargetData.h"
21 #include "llvm/Support/CommandLine.h"
22 #include "llvm/Support/ManagedStatic.h"
23 #include "llvm/Support/MemoryBuffer.h"
24 #include "llvm/Support/PrettyStackTrace.h"
25 #include "llvm/System/Signals.h"
31 // InputFilename - The filename to read from.
32 static cl::opt<std::string>
33 InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
34 cl::init("-"), cl::value_desc("filename"));
36 static cl::opt<std::string>
37 OutputFilename("o", cl::desc("Specify output filename"),
38 cl::value_desc("filename"), cl::init("-"));
41 Force("f", cl::desc("Overwrite output files"));
44 DeleteFn("delete", cl::desc("Delete specified Globals from Module"));
48 cl::desc("Turn external linkage for callees of function to delete"));
50 // ExtractFunc - The function to extract from the module...
51 static cl::opt<std::string>
52 ExtractFunc("func", cl::desc("Specify function to extract"), cl::init(""),
53 cl::value_desc("function"));
55 // ExtractGlobal - The global to extract from the module...
56 static cl::opt<std::string>
57 ExtractGlobal("glob", cl::desc("Specify global to extract"), cl::init(""),
58 cl::value_desc("global"));
60 int main(int argc, char **argv) {
61 // Print a stack trace if we signal out.
62 sys::PrintStackTraceOnErrorSignal();
63 PrettyStackTraceProgram X(argc, argv);
66 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
67 cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");
69 std::auto_ptr<Module> M;
71 MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(InputFilename);
73 cerr << argv[0] << ": Error reading file '" + InputFilename + "'\n";
76 M.reset(ParseBitcodeFile(Buffer, &Context));
81 cerr << argv[0] << ": bitcode didn't read correctly.\n";
85 // Figure out which function we should extract
86 GlobalVariable *G = !ExtractGlobal.empty() ?
87 M.get()->getNamedGlobal(ExtractGlobal) : 0;
89 // Figure out which function we should extract
90 if (ExtractFunc.empty() && ExtractGlobal.empty()) ExtractFunc = "main";
91 Function *F = M.get()->getFunction(ExtractFunc);
93 if (F == 0 && G == 0) {
94 cerr << argv[0] << ": program doesn't contain function named '"
95 << ExtractFunc << "' or a global named '" << ExtractGlobal << "'!\n";
99 // In addition to deleting all other functions, we also want to spiff it
100 // up a little bit. Do this now.
102 Passes.add(new TargetData(M.get())); // Use correct TargetData
103 // Either isolate the function or delete it from the Module
104 std::vector<GlobalValue*> GVs;
105 if (F) GVs.push_back(F);
106 if (G) GVs.push_back(G);
108 Passes.add(createGVExtractionPass(GVs, DeleteFn, Relink));
110 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
111 Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
112 Passes.add(createStripDeadPrototypesPass()); // Remove dead func decls
114 std::ostream *Out = 0;
116 if (OutputFilename != "-") { // Not stdout?
117 if (!Force && std::ifstream(OutputFilename.c_str())) {
118 // If force is not specified, make sure not to overwrite a file!
119 cerr << argv[0] << ": error opening '" << OutputFilename
120 << "': file exists!\n"
121 << "Use -f command line argument to force output\n";
124 std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
126 Out = new std::ofstream(OutputFilename.c_str(), io_mode);
127 } else { // Specified stdout
128 // FIXME: cout is not binary!
132 Passes.add(CreateBitcodeWriterPass(*Out));
133 Passes.run(*M.get());
135 if (Out != &std::cout)