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 "llvm/System/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"));
40 DeleteFn("delete", cl::desc("Delete specified function from Module"));
42 // ExtractFunc - The function to extract from the module... defaults to main.
43 static cl::opt<std::string>
44 ExtractFunc("func", cl::desc("Specify function to extract"), cl::init("main"),
45 cl::value_desc("function"));
47 int main(int argc, char **argv) {
48 cl::ParseCommandLineOptions(argc, argv, " llvm extractor\n");
49 PrintStackTraceOnErrorSignal();
51 std::auto_ptr<Module> M(ParseBytecodeFile(InputFilename));
53 std::cerr << argv[0] << ": bytecode didn't read correctly.\n";
57 // Figure out which function we should extract
58 Function *F = M.get()->getNamedFunction(ExtractFunc);
60 std::cerr << argv[0] << ": program doesn't contain function named '"
61 << ExtractFunc << "'!\n";
65 // In addition to deleting all other functions, we also want to spiff it up a
66 // little bit. Do this now.
69 Passes.add(new TargetData("extract", M.get())); // Use correct TargetData
70 // Either isolate the function or delete it from the Module
71 Passes.add(createFunctionExtractionPass(F, DeleteFn));
72 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
73 Passes.add(createFunctionResolvingPass()); // Delete prototypes
74 Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
76 std::ostream *Out = 0;
78 if (OutputFilename != "-") { // Not stdout?
79 if (!Force && std::ifstream(OutputFilename.c_str())) {
80 // If force is not specified, make sure not to overwrite a file!
81 std::cerr << argv[0] << ": error opening '" << OutputFilename
82 << "': file exists!\n"
83 << "Use -f command line argument to force output\n";
86 Out = new std::ofstream(OutputFilename.c_str());
87 } else { // Specified stdout
91 Passes.add(new WriteBytecodePass(Out)); // Write bytecode to file...
94 if (Out != &std::cout)