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/Streams.h"
23 #include "llvm/System/Signals.h"
29 // InputFilename - The filename to read from.
30 static cl::opt<std::string>
31 InputFilename(cl::Positional, cl::desc("<input bytecode file>"),
32 cl::init("-"), cl::value_desc("filename"));
34 static cl::opt<std::string>
35 OutputFilename("o", cl::desc("Specify output filename"),
36 cl::value_desc("filename"), cl::init("-"));
39 Force("f", cl::desc("Overwrite output files"));
42 DeleteFn("delete", cl::desc("Delete specified function from Module"));
44 // ExtractFunc - The function to extract from the module... defaults to main.
45 static cl::opt<std::string>
46 ExtractFunc("func", cl::desc("Specify function to extract"), cl::init("main"),
47 cl::value_desc("function"));
49 int main(int argc, char **argv) {
51 cl::ParseCommandLineOptions(argc, argv, " llvm extractor\n");
52 sys::PrintStackTraceOnErrorSignal();
54 std::auto_ptr<Module> M(ParseBytecodeFile(InputFilename));
56 llvm_cerr << argv[0] << ": bytecode didn't read correctly.\n";
60 // Figure out which function we should extract
61 Function *F = M.get()->getNamedFunction(ExtractFunc);
63 llvm_cerr << argv[0] << ": program doesn't contain function named '"
64 << ExtractFunc << "'!\n";
68 // In addition to deleting all other functions, we also want to spiff it
69 // up a little bit. Do this now.
71 Passes.add(new TargetData(M.get())); // Use correct TargetData
72 // Either isolate the function or delete it from the Module
73 Passes.add(createFunctionExtractionPass(F, DeleteFn));
74 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
75 Passes.add(createFunctionResolvingPass()); // Delete prototypes
76 Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
78 std::ostream *Out = 0;
80 if (OutputFilename != "-") { // Not stdout?
81 if (!Force && std::ifstream(OutputFilename.c_str())) {
82 // If force is not specified, make sure not to overwrite a file!
83 llvm_cerr << argv[0] << ": error opening '" << OutputFilename
84 << "': file exists!\n"
85 << "Use -f command line argument to force output\n";
88 std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
90 Out = new std::ofstream(OutputFilename.c_str(), io_mode);
91 } else { // Specified stdout
92 // FIXME: cout is not binary!
97 Passes.add(new WriteBytecodePass(&L)); // Write bytecode to file...
100 if (Out != &std::cout)
103 } catch (const std::string& msg) {
104 llvm_cerr << argv[0] << ": " << msg << "\n";
106 llvm_cerr << argv[0] << ": Unexpected unknown exception occurred.\n";