1 //===- llvm-extract.cpp - LLVM function extraction utility ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // 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/LLVMContext.h"
16 #include "llvm/Module.h"
17 #include "llvm/PassManager.h"
18 #include "llvm/Assembly/PrintModulePass.h"
19 #include "llvm/Bitcode/ReaderWriter.h"
20 #include "llvm/Transforms/IPO.h"
21 #include "llvm/Target/TargetData.h"
22 #include "llvm/Support/CommandLine.h"
23 #include "llvm/Support/IRReader.h"
24 #include "llvm/Support/ManagedStatic.h"
25 #include "llvm/Support/PrettyStackTrace.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include "llvm/Support/SystemUtils.h"
28 #include "llvm/System/Signals.h"
32 // InputFilename - The filename to read from.
33 static cl::opt<std::string>
34 InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
35 cl::init("-"), cl::value_desc("filename"));
37 static cl::opt<std::string>
38 OutputFilename("o", cl::desc("Specify output filename"),
39 cl::value_desc("filename"), cl::init("-"));
42 Force("f", cl::desc("Enable binary output on terminals"));
45 DeleteFn("delete", cl::desc("Delete specified Globals from Module"));
49 cl::desc("Turn external linkage for callees of function to delete"));
51 // ExtractFuncs - The functions to extract from the module...
52 static cl::list<std::string>
53 ExtractFuncs("func", cl::desc("Specify function to extract"),
54 cl::ZeroOrMore, cl::value_desc("function"));
56 // ExtractGlobals - The globals to extract from the module...
57 static cl::list<std::string>
58 ExtractGlobals("glob", cl::desc("Specify global to extract"),
59 cl::ZeroOrMore, cl::value_desc("global"));
63 cl::desc("Write output as LLVM assembly"), cl::Hidden);
65 int main(int argc, char **argv) {
66 // Print a stack trace if we signal out.
67 sys::PrintStackTraceOnErrorSignal();
68 PrettyStackTraceProgram X(argc, argv);
70 LLVMContext &Context = getGlobalContext();
71 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
72 cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");
75 std::auto_ptr<Module> M;
76 M.reset(ParseIRFile(InputFilename, Err, Context));
79 Err.Print(argv[0], errs());
83 std::vector<GlobalValue *> GVs;
85 // Figure out which globals we should extract.
86 for (size_t i = 0, e = ExtractGlobals.size(); i != e; ++i) {
87 GlobalValue *GV = M.get()->getNamedGlobal(ExtractGlobals[i]);
89 errs() << argv[0] << ": program doesn't contain global named '"
90 << ExtractGlobals[i] << "'!\n";
96 // Figure out which functions we should extract.
97 for (size_t i = 0, e = ExtractFuncs.size(); i != e; ++i) {
98 GlobalValue *GV = M.get()->getFunction(ExtractFuncs[i]);
100 errs() << argv[0] << ": program doesn't contain function named '"
101 << ExtractFuncs[i] << "'!\n";
107 // In addition to deleting all other functions, we also want to spiff it
108 // up a little bit. Do this now.
110 Passes.add(new TargetData(M.get())); // Use correct TargetData
112 Passes.add(createGVExtractionPass(GVs, DeleteFn, Relink));
114 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
115 Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
116 Passes.add(createStripDeadPrototypesPass()); // Remove dead func decls
118 // Make sure that the Output file gets unlinked from the disk if we get a
120 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
122 std::string ErrorInfo;
123 raw_fd_ostream Out(OutputFilename.c_str(), ErrorInfo,
124 raw_fd_ostream::F_Binary);
125 if (!ErrorInfo.empty()) {
126 errs() << ErrorInfo << '\n';
131 Passes.add(createPrintModulePass(&Out));
132 else if (Force || !CheckBitcodeOutputToConsole(Out, true))
133 Passes.add(createBitcodeWriterPass(Out));
135 Passes.run(*M.get());