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//===- GenerateCode.cpp - Functions for generating executable files ------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains functions for generating executable files once linking
// has finished. This includes generating a shell script to run the JIT or
// a native executable derived from the bytecode.
//
//===----------------------------------------------------------------------===//
#include "gccld.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Bytecode/WriteBytecodePass.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/Linker.h"
#include "Support/SystemUtils.h"
/// GenerateBytecode - generates a bytecode file from the specified module.
///
/// Inputs:
/// M - The module for which bytecode should be generated.
/// Strip - Flags whether symbols should be stripped from the output.
/// Internalize - Flags whether all symbols should be marked internal.
/// Out - Pointer to file stream to which to write the output.
///
/// Outputs:
/// None.
///
/// Returns non-zero value on error.
///
int
GenerateBytecode (Module *M, bool Strip, bool Internalize, std::ostream *Out) {
// In addition to just linking the input from GCC, we also want to spiff it up
// a little bit. Do this now.
PassManager Passes;
// Add an appropriate TargetData instance for this module...
Passes.add(new TargetData("gccld", M));
// Linking modules together can lead to duplicated global constants, only keep
// one copy of each constant...
Passes.add(createConstantMergePass());
// If the -s command line option was specified, strip the symbols out of the
// resulting program to make it smaller. -s is a GCC option that we are
// supporting.
if (Strip)
Passes.add(createSymbolStrippingPass());
// Often if the programmer does not specify proper prototypes for the
// functions they are calling, they end up calling a vararg version of the
// function that does not get a body filled in (the real function has typed
// arguments). This pass merges the two functions.
Passes.add(createFunctionResolvingPass());
if (Internalize) {
// Now that composite has been compiled, scan through the module, looking
// for a main function. If main is defined, mark all other functions
// internal.
Passes.add(createInternalizePass());
}
// Remove unused arguments from functions...
Passes.add(createDeadArgEliminationPass());
// The FuncResolve pass may leave cruft around if functions were prototyped
// differently than they were defined. Remove this cruft.
Passes.add(createInstructionCombiningPass());
// Delete basic blocks, which optimization passes may have killed...
Passes.add(createCFGSimplificationPass());
// Now that we have optimized the program, discard unreachable functions...
Passes.add(createGlobalDCEPass());
// Add the pass that writes bytecode to the output file...
Passes.add(new WriteBytecodePass(Out));
// Run our queue of passes all at once now, efficiently.
Passes.run(*M);
return 0;
}
/// GenerateAssembly - generates a native assembly language source file from the
/// specified bytecode file.
///
/// Inputs:
/// InputFilename - The name of the output bytecode file.
/// OutputFilename - The name of the file to generate.
/// llc - The pathname to use for LLC.
/// envp - The environment to use when running LLC.
///
/// Outputs:
/// None.
///
/// Return non-zero value on error.
///
int
GenerateAssembly(const std::string &OutputFilename,
const std::string &InputFilename,
const std::string &llc,
char ** const envp)
{
// Run LLC to convert the bytecode file into assembly code.
const char *cmd[8];
cmd[0] = llc.c_str();
cmd[1] = "-f";
cmd[2] = "-o";
cmd[3] = OutputFilename.c_str();
cmd[4] = InputFilename.c_str();
cmd[5] = NULL;
return ExecWait(cmd, envp);
}
/// GenerateNative - generates a native assembly language source file from the
/// specified assembly source file.
///
/// Inputs:
/// InputFilename - The name of the output bytecode file.
/// OutputFilename - The name of the file to generate.
/// Libraries - The list of libraries with which to link.
/// LibPaths - The list of directories in which to find libraries.
/// gcc - The pathname to use for GGC.
/// envp - A copy of the process's current environment.
///
/// Outputs:
/// None.
///
/// Returns non-zero value on error.
///
int
GenerateNative(const std::string &OutputFilename,
const std::string &InputFilename,
const std::vector<std::string> &Libraries,
const std::vector<std::string> &LibPaths,
const std::string &gcc,
char ** const envp) {
// Remove these environment variables from the environment of the
// programs that we will execute. It appears that GCC sets these
// environment variables so that the programs it uses can configure
// themselves identically.
//
// However, when we invoke GCC below, we want it to use its normal
// configuration. Hence, we must sanitize its environment.
char ** clean_env = CopyEnv(envp);
if (clean_env == NULL)
return 1;
RemoveEnv("LIBRARY_PATH", clean_env);
RemoveEnv("COLLECT_GCC_OPTIONS", clean_env);
RemoveEnv("GCC_EXEC_PREFIX", clean_env);
RemoveEnv("COMPILER_PATH", clean_env);
RemoveEnv("COLLECT_GCC", clean_env);
std::vector<const char *> cmd;
// Run GCC to assemble and link the program into native code.
//
// Note:
// We can't just assemble and link the file with the system assembler
// and linker because we don't know where to put the _start symbol.
// GCC mysteriously knows how to do it.
cmd.push_back(gcc.c_str());
cmd.push_back("-o");
cmd.push_back(OutputFilename.c_str());
cmd.push_back(InputFilename.c_str());
// Adding the library paths creates a problem for native generation. If we
// include the search paths from llvmgcc, then we'll be telling normal gcc
// to look inside of llvmgcc's library directories for libraries. This is
// bad because those libraries hold only bytecode files (not native object
// files). In the end, we attempt to link the bytecode libgcc into a native
// program.
#if 0
// Add in the library path options.
for (unsigned index=0; index < LibPaths.size(); index++) {
cmd.push_back("-L");
cmd.push_back(LibPaths[index].c_str());
}
#endif
// Add in the libraries to link.
std::vector<std::string> Libs(Libraries);
for (unsigned index = 0; index < Libs.size(); index++) {
Libs[index] = "-l" + Libs[index];
cmd.push_back(Libs[index].c_str());
}
cmd.push_back(NULL);
// Run the compiler to assembly and link together the program.
return ExecWait(&(cmd[0]), clean_env);
}
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