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/ManagedStatic.h"
23 #include "llvm/Support/Streams.h"
24 #include "llvm/System/Signals.h"
30 // InputFilename - The filename to read from.
31 static cl::opt<std::string>
32 InputFilename(cl::Positional, cl::desc("<input bytecode file>"),
33 cl::init("-"), cl::value_desc("filename"));
35 static cl::opt<std::string>
36 OutputFilename("o", cl::desc("Specify output filename"),
37 cl::value_desc("filename"), cl::init("-"));
40 Force("f", cl::desc("Overwrite output files"));
43 DeleteFn("delete", cl::desc("Delete specified function from Module"));
47 cl::desc("Turn external linkage for callees of function to delete"));
49 // ExtractFunc - The function to extract from the module... defaults to main.
50 static cl::opt<std::string>
51 ExtractFunc("func", cl::desc("Specify function to extract"), cl::init("main"),
52 cl::value_desc("function"));
54 int main(int argc, char **argv) {
55 llvm_shutdown_obj X; // Call llvm_shutdown() on exit.
57 cl::ParseCommandLineOptions(argc, argv, " llvm extractor\n");
58 sys::PrintStackTraceOnErrorSignal();
60 std::auto_ptr<Module> M(ParseBytecodeFile(InputFilename));
62 cerr << argv[0] << ": bytecode didn't read correctly.\n";
66 // Figure out which function we should extract
67 Function *F = M.get()->getNamedFunction(ExtractFunc);
69 cerr << argv[0] << ": program doesn't contain function named '"
70 << ExtractFunc << "'!\n";
74 // In addition to deleting all other functions, we also want to spiff it
75 // up a little bit. Do this now.
77 Passes.add(new TargetData(M.get())); // Use correct TargetData
78 // Either isolate the function or delete it from the Module
79 Passes.add(createFunctionExtractionPass(F, DeleteFn, Relink));
81 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
82 Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
84 std::ostream *Out = 0;
86 if (OutputFilename != "-") { // Not stdout?
87 if (!Force && std::ifstream(OutputFilename.c_str())) {
88 // If force is not specified, make sure not to overwrite a file!
89 cerr << argv[0] << ": error opening '" << OutputFilename
90 << "': file exists!\n"
91 << "Use -f command line argument to force output\n";
94 std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
96 Out = new std::ofstream(OutputFilename.c_str(), io_mode);
97 } else { // Specified stdout
98 // FIXME: cout is not binary!
103 Passes.add(new WriteBytecodePass(&L)); // Write bytecode to file...
104 Passes.run(*M.get());
106 if (Out != &std::cout)
109 } catch (const std::string& msg) {
110 cerr << argv[0] << ": " << msg << "\n";
112 cerr << argv[0] << ": Unexpected unknown exception occurred.\n";