llvm-project/llvm/tools/gccas/gccas.cpp

81 lines
2.7 KiB
C++

//===------------------------------------------------------------------------===
// LLVM 'GCCAS' UTILITY
//
// This utility is designed to be used by the GCC frontend for creating
// bytecode files from it's intermediate llvm assembly. The requirements for
// this utility are thus slightly different than that of the standard as util.
//
//===------------------------------------------------------------------------===
#include "llvm/Module.h"
#include "llvm/Assembly/Parser.h"
#include "llvm/Transforms/CleanupGCCOutput.h"
#include "llvm/Transforms/LevelChange.h"
#include "llvm/Optimizations/ConstantProp.h"
#include "llvm/Optimizations/DCE.h"
#include "llvm/Transforms/ConstantMerge.h"
#include "llvm/Bytecode/Writer.h"
#include "llvm/Support/CommandLine.h"
#include <memory>
#include <fstream>
#include <string>
cl::String InputFilename ("", "Parse <arg> file, compile to bytecode",
cl::Required, "");
cl::String OutputFilename("o", "Override output filename", cl::NoFlags, "");
int main(int argc, char **argv) {
cl::ParseCommandLineOptions(argc, argv, " llvm .s -> .o assembler for GCC\n");
ostream *Out = 0;
std::auto_ptr<Module> M;
try {
// Parse the file now...
M.reset(ParseAssemblyFile(InputFilename));
} catch (const ParseException &E) {
cerr << E.getMessage() << endl;
return 1;
}
if (M.get() == 0) {
cerr << "assembly didn't read correctly.\n";
return 1;
}
if (OutputFilename == "") { // Didn't specify an output filename?
string IFN = InputFilename;
int Len = IFN.length();
if (IFN[Len-2] == '.' && IFN[Len-1] == 's') { // Source ends in .s?
OutputFilename = string(IFN.begin(), IFN.end()-2);
} else {
OutputFilename = IFN; // Append a .o to it
}
OutputFilename += ".o";
}
Out = new ofstream(OutputFilename.c_str(), ios::out);
if (!Out->good()) {
cerr << "Error opening " << OutputFilename << "!\n";
return 1;
}
// In addition to just parsing the input from GCC, we also want to spiff it up
// a little bit. Do this now.
//
vector<Pass*> Passes;
Passes.push_back(new CleanupGCCOutput()); // Fix gccisms
Passes.push_back(new RaisePointerReferences()); // Fix general low level code
Passes.push_back(new opt::ConstantPropogation());// Trivial const prop
Passes.push_back(new opt::DeadCodeElimination());// Trivial DCE
Passes.push_back(new ConstantMerge()); // Merge dup global constants
// Run our queue of passes all at once now, efficiently. This form of
// runAllPasses frees the Pass objects after runAllPasses completes.
//
Pass::runAllPassesAndFree(M.get(), Passes);
WriteBytecodeToFile(M.get(), *Out);
return 0;
}