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"
26 // InputFilename - The filename to read from.
27 static cl::opt<std::string>
28 InputFilename(cl::Positional, cl::desc("<input bytecode file>"),
29 cl::init("-"), cl::value_desc("filename"));
31 static cl::opt<std::string>
32 OutputFilename("o", cl::desc("Specify output filename"),
33 cl::value_desc("filename"), cl::init("-"));
36 Force("f", cl::desc("Overwrite output files"));
38 // ExtractFunc - The function to extract from the module... defaults to main.
39 static cl::opt<std::string>
40 ExtractFunc("func", cl::desc("Specify function to extract"), cl::init("main"),
41 cl::value_desc("function"));
43 int main(int argc, char **argv) {
44 cl::ParseCommandLineOptions(argc, argv, " llvm extractor\n");
46 std::auto_ptr<Module> M(ParseBytecodeFile(InputFilename));
48 std::cerr << argv[0] << ": bytecode didn't read correctly.\n";
52 // Figure out which function we should extract
53 Function *F = M.get()->getNamedFunction(ExtractFunc);
55 std::cerr << argv[0] << ": program doesn't contain function named '"
56 << ExtractFunc << "'!\n";
60 // In addition to deleting all other functions, we also want to spiff it up a
61 // little bit. Do this now.
64 Passes.add(new TargetData("extract", M.get())); // Use correct TargetData
65 Passes.add(createFunctionExtractionPass(F)); // Extract the function
66 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
67 Passes.add(createFunctionResolvingPass()); // Delete prototypes
68 Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
70 std::ostream *Out = 0;
72 if (OutputFilename != "-") { // Not stdout?
73 if (!Force && std::ifstream(OutputFilename.c_str())) {
74 // If force is not specified, make sure not to overwrite a file!
75 std::cerr << argv[0] << ": error opening '" << OutputFilename
76 << "': file exists!\n"
77 << "Use -f command line argument to force output\n";
80 Out = new std::ofstream(OutputFilename.c_str());
81 } else { // Specified stdout
85 Passes.add(new WriteBytecodePass(Out)); // Write bytecode to file...
88 if (Out != &std::cout)