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Diffstat (limited to 'tools/llvm-ld/llvm-ld.cpp')
-rw-r--r-- | tools/llvm-ld/llvm-ld.cpp | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/tools/llvm-ld/llvm-ld.cpp b/tools/llvm-ld/llvm-ld.cpp new file mode 100644 index 0000000000..d59b18acb5 --- /dev/null +++ b/tools/llvm-ld/llvm-ld.cpp @@ -0,0 +1,303 @@ +//===- llvm-ld.cpp - LLVM 'ld' compatible linker --------------------------===// +// +// 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 utility is intended to be compatible with GCC, and follows standard +// system 'ld' conventions. As such, the default output file is ./a.out. +// Additionally, this program outputs a shell script that is used to invoke LLI +// to execute the program. In this manner, the generated executable (a.out for +// example), is directly executable, whereas the bytecode file actually lives in +// the a.out.bc file generated by this program. Also, Force is on by default. +// +// Note that if someone (or a script) deletes the executable program generated, +// the .bc file will be left around. Considering that this is a temporary hack, +// I'm not too worried about this. +// +//===----------------------------------------------------------------------===// + +#include "llvm-ld.h" +#include "llvm/Module.h" +#include "llvm/PassManager.h" +#include "llvm/Bytecode/Reader.h" +#include "llvm/Bytecode/WriteBytecodePass.h" +#include "llvm/Target/TargetData.h" +#include "llvm/Transforms/IPO.h" +#include "llvm/Transforms/Scalar.h" +#include "llvm/Support/Linker.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Support/FileUtilities.h" +#include "llvm/System/Signals.h" +#include "llvm/Support/SystemUtils.h" +#include <fstream> +#include <memory> +using namespace llvm; + +enum OptimizationLevels { + OPT_FAST_COMPILE, + OPT_SIMPLE, + OPT_AGGRESSIVE, + OPT_LINK_TIME, + OPT_AGGRESSIVE_LINK_TIME +}; + +namespace { + cl::list<std::string> + InputFilenames(cl::Positional, cl::desc("<input bytecode files>"), + cl::OneOrMore); + + cl::opt<std::string> + OutputFilename("o", cl::desc("Override output filename"), cl::init("a.out"), + cl::value_desc("filename")); + + cl::opt<bool> + Verbose("v", cl::desc("Print information about actions taken")); + + cl::list<std::string> + LibPaths("L", cl::desc("Specify a library search path"), cl::Prefix, + cl::value_desc("directory")); + + cl::list<std::string> + Libraries("l", cl::desc("Specify libraries to link to"), cl::Prefix, + cl::value_desc("library prefix")); + + cl::opt<bool> + Strip("s", cl::desc("Strip symbol info from executable")); + + cl::opt<bool> + NoInternalize("disable-internalize", + cl::desc("Do not mark all symbols as internal")); + cl::alias + ExportDynamic("export-dynamic", cl::desc("Alias for -disable-internalize"), + cl::aliasopt(NoInternalize)); + + cl::opt<bool> + LinkAsLibrary("link-as-library", cl::desc("Link the .bc files together as a" + " library, not an executable")); + cl::alias + Relink("r", cl::desc("Alias for -link-as-library"), + cl::aliasopt(LinkAsLibrary)); + + cl::opt<bool> + Native("native", + cl::desc("Generate a native binary instead of a shell script")); + cl::opt<bool> + NativeCBE("native-cbe", + cl::desc("Generate a native binary with the C backend and GCC")); + + // Compatibility options that are ignored but supported by LD + cl::opt<std::string> + CO3("soname", cl::Hidden, cl::desc("Compatibility option: ignored")); + cl::opt<std::string> + CO4("version-script", cl::Hidden, cl::desc("Compatibility option: ignored")); + cl::opt<bool> + CO5("eh-frame-hdr", cl::Hidden, cl::desc("Compatibility option: ignored")); + cl::opt<std::string> + CO6("h", cl::Hidden, cl::desc("Compatibility option: ignored")); + + cl::opt<OptimizationLevels> OptLevel( + cl::desc("Choose level of optimization to apply:"), + cl::init(OPT_FAST_COMPILE), cl::values( + clEnumValN(OPT_FAST_COMPILE,"O0", + "An alias for the -O1 option."), + clEnumValN(OPT_FAST_COMPILE,"O1", + "Optimize for linking speed, not execution speed."), + clEnumValN(OPT_SIMPLE,"O2", + "Perform only required/minimal optimizations"), + clEnumValN(OPT_AGGRESSIVE,"O3", + "An alias for the -O2 option."), + clEnumValN(OPT_LINK_TIME,"O4", + "Perform standard link time optimizations"), + clEnumValN(OPT_AGGRESSIVE_LINK_TIME,"O5", + "Perform aggressive link time optimizations"), + clEnumValEnd + ) + ); +} + +/// PrintAndReturn - Prints a message to standard error and returns true. +/// +/// Inputs: +/// progname - The name of the program (i.e. argv[0]). +/// Message - The message to print to standard error. +/// +static int PrintAndReturn(const char *progname, const std::string &Message) { + std::cerr << progname << ": " << Message << "\n"; + return 1; +} + +/// EmitShellScript - Output the wrapper file that invokes the JIT on the LLVM +/// bytecode file for the program. +static void EmitShellScript(char **argv) { +#if defined(_WIN32) || defined(__CYGWIN__) + // Windows doesn't support #!/bin/sh style shell scripts in .exe files. To + // support windows systems, we copy the llvm-stub.exe executable from the + // build tree to the destination file. + std::string llvmstub = FindExecutable("llvm-stub.exe", argv[0]); + if (llvmstub.empty()) { + std::cerr << "Could not find llvm-stub.exe executable!\n"; + exit(1); + } + if (CopyFile(OutputFilename, llvmstub)) { + std::cerr << "Could not copy the llvm-stub.exe executable!\n"; + exit(1); + } + return; +#endif + + // Output the script to start the program... + std::ofstream Out2(OutputFilename.c_str()); + if (!Out2.good()) + exit(PrintAndReturn(argv[0], "error opening '" + OutputFilename + + "' for writing!")); + + Out2 << "#!/bin/sh\n"; + // Allow user to setenv LLVMINTERP if lli is not in their PATH. + Out2 << "lli=${LLVMINTERP-lli}\n"; + Out2 << "exec $lli \\\n"; + // gcc accepts -l<lib> and implicitly searches /lib and /usr/lib. + LibPaths.push_back("/lib"); + LibPaths.push_back("/usr/lib"); + LibPaths.push_back("/usr/X11R6/lib"); + // We don't need to link in libc! In fact, /usr/lib/libc.so may not be a + // shared object at all! See RH 8: plain text. + std::vector<std::string>::iterator libc = + std::find(Libraries.begin(), Libraries.end(), "c"); + if (libc != Libraries.end()) Libraries.erase(libc); + // List all the shared object (native) libraries this executable will need + // on the command line, so that we don't have to do this manually! + for (std::vector<std::string>::iterator i = Libraries.begin(), + e = Libraries.end(); i != e; ++i) { + std::string FullLibraryPath = FindLib(*i, LibPaths, true); + if (!FullLibraryPath.empty() && IsSharedObject(FullLibraryPath)) + Out2 << " -load=" << FullLibraryPath << " \\\n"; + } + Out2 << " $0.bc ${1+\"$@\"}\n"; + Out2.close(); +} + +int main(int argc, char **argv, char **envp) { + cl::ParseCommandLineOptions(argc, argv, " llvm linker for GCC\n"); + sys::PrintStackTraceOnErrorSignal(); + + std::string ModuleID("gccld-output"); + std::auto_ptr<Module> Composite(new Module(ModuleID)); + + // We always look first in the current directory when searching for libraries. + LibPaths.insert(LibPaths.begin(), "."); + + // If the user specified an extra search path in their environment, respect + // it. + if (char *SearchPath = getenv("LLVM_LIB_SEARCH_PATH")) + LibPaths.push_back(SearchPath); + + // Remove any consecutive duplicates of the same library... + Libraries.erase(std::unique(Libraries.begin(), Libraries.end()), + Libraries.end()); + + // Link in all of the files + if (LinkFiles(argv[0], Composite.get(), InputFilenames, Verbose)) + return 1; // Error already printed + + if (!LinkAsLibrary) + LinkLibraries(argv[0], Composite.get(), Libraries, LibPaths, + Verbose, Native); + + // Link in all of the libraries next... + + // Create the output file. + std::string RealBytecodeOutput = OutputFilename; + if (!LinkAsLibrary) RealBytecodeOutput += ".bc"; + std::ofstream Out(RealBytecodeOutput.c_str()); + if (!Out.good()) + return PrintAndReturn(argv[0], "error opening '" + RealBytecodeOutput + + "' for writing!"); + + // Ensure that the bytecode file gets removed from the disk if we get a + // SIGINT signal. + sys::RemoveFileOnSignal(RealBytecodeOutput); + + // Generate the bytecode file. + if (GenerateBytecode(Composite.get(), Strip, !NoInternalize, &Out)) { + Out.close(); + return PrintAndReturn(argv[0], "error generating bytecode"); + } + + // Close the bytecode file. + Out.close(); + + // If we are not linking a library, generate either a native executable + // or a JIT shell script, depending upon what the user wants. + if (!LinkAsLibrary) { + // If the user wants to generate a native executable, compile it from the + // bytecode file. + // + // Otherwise, create a script that will run the bytecode through the JIT. + if (Native) { + // Name of the Assembly Language output file + std::string AssemblyFile = OutputFilename + ".s"; + + // Mark the output files for removal if we get an interrupt. + sys::RemoveFileOnSignal(AssemblyFile); + sys::RemoveFileOnSignal(OutputFilename); + + // Determine the locations of the llc and gcc programs. + std::string llc = FindExecutable("llc", argv[0]); + std::string gcc = FindExecutable("gcc", argv[0]); + if (llc.empty()) + return PrintAndReturn(argv[0], "Failed to find llc"); + + if (gcc.empty()) + return PrintAndReturn(argv[0], "Failed to find gcc"); + + // Generate an assembly language file for the bytecode. + if (Verbose) std::cout << "Generating Assembly Code\n"; + GenerateAssembly(AssemblyFile, RealBytecodeOutput, llc, envp); + if (Verbose) std::cout << "Generating Native Code\n"; + GenerateNative(OutputFilename, AssemblyFile, Libraries, LibPaths, + gcc, envp); + + // Remove the assembly language file. + removeFile (AssemblyFile); + } else if (NativeCBE) { + std::string CFile = OutputFilename + ".cbe.c"; + + // Mark the output files for removal if we get an interrupt. + sys::RemoveFileOnSignal(CFile); + sys::RemoveFileOnSignal(OutputFilename); + + // Determine the locations of the llc and gcc programs. + std::string llc = FindExecutable("llc", argv[0]); + std::string gcc = FindExecutable("gcc", argv[0]); + if (llc.empty()) + return PrintAndReturn(argv[0], "Failed to find llc"); + if (gcc.empty()) + return PrintAndReturn(argv[0], "Failed to find gcc"); + + // Generate an assembly language file for the bytecode. + if (Verbose) std::cout << "Generating Assembly Code\n"; + GenerateCFile(CFile, RealBytecodeOutput, llc, envp); + if (Verbose) std::cout << "Generating Native Code\n"; + GenerateNative(OutputFilename, CFile, Libraries, LibPaths, gcc, envp); + + // Remove the assembly language file. + removeFile(CFile); + + } else { + EmitShellScript(argv); + } + + // Make the script executable... + MakeFileExecutable(OutputFilename); + + // Make the bytecode file readable and directly executable in LLEE as well + MakeFileExecutable(RealBytecodeOutput); + MakeFileReadable(RealBytecodeOutput); + } + + return 0; +} |