llvm/tools/llvm-extract/llvm-extract.cpp
2008-03-07 20:10:54 +00:00

133 lines
4.4 KiB
C++

//===- llvm-extract.cpp - LLVM function extraction utility ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This utility changes the input module to only contain a single function,
// which is primarily used for debugging transformations.
//
//===----------------------------------------------------------------------===//
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/System/Signals.h"
#include <iostream>
#include <memory>
#include <fstream>
using namespace llvm;
// InputFilename - The filename to read from.
static cl::opt<std::string>
InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
cl::init("-"), cl::value_desc("filename"));
static cl::opt<std::string>
OutputFilename("o", cl::desc("Specify output filename"),
cl::value_desc("filename"), cl::init("-"));
static cl::opt<bool>
Force("f", cl::desc("Overwrite output files"));
static cl::opt<bool>
DeleteFn("delete", cl::desc("Delete specified Globals from Module"));
static cl::opt<bool>
Relink("relink",
cl::desc("Turn external linkage for callees of function to delete"));
// ExtractFunc - The function to extract from the module...
static cl::opt<std::string>
ExtractFunc("func", cl::desc("Specify function to extract"), cl::init(""),
cl::value_desc("function"));
// ExtractGlobal - The global to extract from the module...
static cl::opt<std::string>
ExtractGlobal("glob", cl::desc("Specify global to extract"), cl::init(""),
cl::value_desc("global"));
int main(int argc, char **argv) {
llvm_shutdown_obj X; // Call llvm_shutdown() on exit.
cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");
sys::PrintStackTraceOnErrorSignal();
std::auto_ptr<Module> M;
MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(InputFilename);
if (Buffer == 0) {
cerr << argv[0] << ": Error reading file '" + InputFilename + "'\n";
return 1;
} else {
M.reset(ParseBitcodeFile(Buffer));
}
delete Buffer;
if (M.get() == 0) {
cerr << argv[0] << ": bitcode didn't read correctly.\n";
return 1;
}
// Figure out which function we should extract
GlobalVariable *G = ExtractGlobal.size() ?
M.get()->getNamedGlobal(ExtractGlobal) : 0;
// Figure out which function we should extract
if (!ExtractFunc.size() && !ExtractGlobal.size()) ExtractFunc = "main";
Function *F = M.get()->getFunction(ExtractFunc);
if (F == 0 && G == 0) {
cerr << argv[0] << ": program doesn't contain function named '"
<< ExtractFunc << "' or a global named '" << ExtractGlobal << "'!\n";
return 1;
}
// In addition to deleting all other functions, we also want to spiff it
// up a little bit. Do this now.
PassManager Passes;
Passes.add(new TargetData(M.get())); // Use correct TargetData
// Either isolate the function or delete it from the Module
std::vector<GlobalValue*> GVs;
if (F) GVs.push_back(F);
if (G) GVs.push_back(G);
Passes.add(createGVExtractionPass(GVs, DeleteFn, Relink));
if (!DeleteFn)
Passes.add(createGlobalDCEPass()); // Delete unreachable globals
Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
Passes.add(createStripDeadPrototypesPass()); // Remove dead func decls
std::ostream *Out = 0;
if (OutputFilename != "-") { // Not stdout?
if (!Force && std::ifstream(OutputFilename.c_str())) {
// If force is not specified, make sure not to overwrite a file!
cerr << argv[0] << ": error opening '" << OutputFilename
<< "': file exists!\n"
<< "Use -f command line argument to force output\n";
return 1;
}
std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
std::ios::binary;
Out = new std::ofstream(OutputFilename.c_str(), io_mode);
} else { // Specified stdout
// FIXME: cout is not binary!
Out = &std::cout;
}
Passes.add(CreateBitcodeWriterPass(*Out));
Passes.run(*M.get());
if (Out != &std::cout)
delete Out;
return 0;
}