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/Bytecode/Reader.h"
18 #include "llvm/Bytecode/WriteBytecodePass.h"
19 #include "llvm/Transforms/IPO.h"
20 #include "llvm/Target/TargetData.h"
21 #include "llvm/Support/CommandLine.h"
22 #include "llvm/Support/Compressor.h"
23 #include "llvm/Support/ManagedStatic.h"
24 #include "llvm/Support/Streams.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 bytecode 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 function from Module"));
48 cl::desc("Turn external linkage for callees of function to delete"));
50 // ExtractFunc - The function to extract from the module... defaults to main.
51 static cl::opt<std::string>
52 ExtractFunc("func", cl::desc("Specify function to extract"), cl::init("main"),
53 cl::value_desc("function"));
55 int main(int argc, char **argv) {
56 llvm_shutdown_obj X; // Call llvm_shutdown() on exit.
58 cl::ParseCommandLineOptions(argc, argv, " llvm extractor\n");
59 sys::PrintStackTraceOnErrorSignal();
61 std::auto_ptr<Module> M(ParseBytecodeFile(InputFilename,
62 Compressor::decompressToNewBuffer));
64 cerr << argv[0] << ": bytecode didn't read correctly.\n";
68 // Figure out which function we should extract
69 Function *F = M.get()->getFunction(ExtractFunc);
71 cerr << argv[0] << ": program doesn't contain function named '"
72 << ExtractFunc << "'!\n";
76 // In addition to deleting all other functions, we also want to spiff it
77 // up a little bit. Do this now.
79 Passes.add(new TargetData(M.get())); // Use correct TargetData
80 // Either isolate the function or delete it from the Module
81 Passes.add(createFunctionExtractionPass(F, DeleteFn, Relink));
83 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
84 Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
85 Passes.add(createStripDeadPrototypesPass()); // Remove dead func decls
87 std::ostream *Out = 0;
89 if (OutputFilename != "-") { // Not stdout?
90 if (!Force && std::ifstream(OutputFilename.c_str())) {
91 // If force is not specified, make sure not to overwrite a file!
92 cerr << argv[0] << ": error opening '" << OutputFilename
93 << "': file exists!\n"
94 << "Use -f command line argument to force output\n";
97 std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
99 Out = new std::ofstream(OutputFilename.c_str(), io_mode);
100 } else { // Specified stdout
101 // FIXME: cout is not binary!
106 Passes.add(new WriteBytecodePass(&L)); // Write bytecode to file...
107 Passes.run(*M.get());
109 if (Out != &std::cout)
112 } catch (const std::string& msg) {
113 cerr << argv[0] << ": " << msg << "\n";
115 cerr << argv[0] << ": Unexpected unknown exception occurred.\n";