1 //===- 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 "Support/CommandLine.h"
22 #include "Support/Signals.h"
27 // InputFilename - The filename to read from.
28 static cl::opt<std::string>
29 InputFilename(cl::Positional, cl::desc("<input bytecode file>"),
30 cl::init("-"), cl::value_desc("filename"));
32 static cl::opt<std::string>
33 OutputFilename("o", cl::desc("Specify output filename"),
34 cl::value_desc("filename"), cl::init("-"));
37 Force("f", cl::desc("Overwrite output files"));
39 // ExtractFunc - The function to extract from the module... defaults to main.
40 static cl::opt<std::string>
41 ExtractFunc("func", cl::desc("Specify function to extract"), cl::init("main"),
42 cl::value_desc("function"));
44 int main(int argc, char **argv) {
45 cl::ParseCommandLineOptions(argc, argv, " llvm extractor\n");
46 PrintStackTraceOnErrorSignal();
48 std::auto_ptr<Module> M(ParseBytecodeFile(InputFilename));
50 std::cerr << argv[0] << ": bytecode didn't read correctly.\n";
54 // Figure out which function we should extract
55 Function *F = M.get()->getNamedFunction(ExtractFunc);
57 std::cerr << argv[0] << ": program doesn't contain function named '"
58 << ExtractFunc << "'!\n";
62 // In addition to deleting all other functions, we also want to spiff it up a
63 // little bit. Do this now.
66 Passes.add(new TargetData("extract", M.get())); // Use correct TargetData
67 Passes.add(createFunctionExtractionPass(F)); // Extract the function
68 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
69 Passes.add(createFunctionResolvingPass()); // Delete prototypes
70 Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
72 std::ostream *Out = 0;
74 if (OutputFilename != "-") { // Not stdout?
75 if (!Force && std::ifstream(OutputFilename.c_str())) {
76 // If force is not specified, make sure not to overwrite a file!
77 std::cerr << argv[0] << ": error opening '" << OutputFilename
78 << "': file exists!\n"
79 << "Use -f command line argument to force output\n";
82 Out = new std::ofstream(OutputFilename.c_str());
83 } else { // Specified stdout
87 Passes.add(new WriteBytecodePass(Out)); // Write bytecode to file...
90 if (Out != &std::cout)