maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/tools/llvm-ld/llvm-ld.cpp

718 lines
25 KiB
C++
Raw Blame History

//===- llvm-ld.cpp - LLVM 'ld' compatible linker --------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file 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 bitcode 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/LinkAllVMCore.h"
#include "llvm/Linker.h"
#include "llvm/LLVMContext.h"
#include "llvm/System/Program.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileUtilities.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/SystemUtils.h"
#include "llvm/System/Signals.h"
#include "llvm/Config/config.h"
#include <memory>
#include <cstring>
using namespace llvm;
// Input/Output Options
static cl::list<std::string> InputFilenames(cl::Positional, cl::OneOrMore,
cl::desc("<input bitcode files>"));
static cl::opt<std::string> OutputFilename("o", cl::init("a.out"),
cl::desc("Override output filename"),
cl::value_desc("filename"));
static cl::opt<std::string> BitcodeOutputFilename("b", cl::init(""),
cl::desc("Override bitcode output filename"),
cl::value_desc("filename"));
static cl::opt<bool> Verbose("v",
cl::desc("Print information about actions taken"));
static cl::list<std::string> LibPaths("L", cl::Prefix,
cl::desc("Specify a library search path"),
cl::value_desc("directory"));
static cl::list<std::string> FrameworkPaths("F", cl::Prefix,
cl::desc("Specify a framework search path"),
cl::value_desc("directory"));
static cl::list<std::string> Libraries("l", cl::Prefix,
cl::desc("Specify libraries to link to"),
cl::value_desc("library prefix"));
static cl::list<std::string> Frameworks("framework",
cl::desc("Specify frameworks to link to"),
cl::value_desc("framework"));
// Options to control the linking, optimization, and code gen processes
static cl::opt<bool> LinkAsLibrary("link-as-library",
cl::desc("Link the .bc files together as a library, not an executable"));
static cl::alias Relink("r", cl::aliasopt(LinkAsLibrary),
cl::desc("Alias for -link-as-library"));
static cl::opt<bool> Native("native",
cl::desc("Generate a native binary instead of a shell script"));
static cl::opt<bool>NativeCBE("native-cbe",
cl::desc("Generate a native binary with the C backend and GCC"));
static cl::list<std::string> PostLinkOpts("post-link-opts",
cl::value_desc("path"),
cl::desc("Run one or more optimization programs after linking"));
static cl::list<std::string> XLinker("Xlinker", cl::value_desc("option"),
cl::desc("Pass options to the system linker"));
// Compatibility options that llvm-ld ignores but are supported for
// compatibility with LD
static cl::opt<std::string> CO3("soname", cl::Hidden,
cl::desc("Compatibility option: ignored"));
static cl::opt<std::string> CO4("version-script", cl::Hidden,
cl::desc("Compatibility option: ignored"));
static cl::opt<bool> CO5("eh-frame-hdr", cl::Hidden,
cl::desc("Compatibility option: ignored"));
static cl::opt<std::string> CO6("h", cl::Hidden,
cl::desc("Compatibility option: ignored"));
static cl::opt<bool> CO7("start-group", cl::Hidden,
cl::desc("Compatibility option: ignored"));
static cl::opt<bool> CO8("end-group", cl::Hidden,
cl::desc("Compatibility option: ignored"));
static cl::opt<std::string> CO9("m", cl::Hidden,
cl::desc("Compatibility option: ignored"));
/// This is just for convenience so it doesn't have to be passed around
/// everywhere.
static std::string progname;
/// PrintAndExit - Prints a message to standard error and exits with error code
///
/// Inputs:
/// Message - The message to print to standard error.
///
static void PrintAndExit(const std::string &Message, int errcode = 1) {
errs() << progname << ": " << Message << "\n";
llvm_shutdown();
exit(errcode);
}
static void PrintCommand(const std::vector<const char*> &args) {
std::vector<const char*>::const_iterator I = args.begin(), E = args.end();
for (; I != E; ++I)
if (*I)
outs() << "'" << *I << "'" << " ";
outs() << "\n"; outs().flush();
}
/// CopyEnv - This function takes an array of environment variables and makes a
/// copy of it. This copy can then be manipulated any way the caller likes
/// without affecting the process's real environment.
///
/// Inputs:
/// envp - An array of C strings containing an environment.
///
/// Return value:
/// NULL - An error occurred.
///
/// Otherwise, a pointer to a new array of C strings is returned. Every string
/// in the array is a duplicate of the one in the original array (i.e. we do
/// not copy the char *'s from one array to another).
///
static char ** CopyEnv(char ** const envp) {
// Count the number of entries in the old list;
unsigned entries; // The number of entries in the old environment list
for (entries = 0; envp[entries] != NULL; entries++)
/*empty*/;
// Add one more entry for the NULL pointer that ends the list.
++entries;
// If there are no entries at all, just return NULL.
if (entries == 0)
return NULL;
// Allocate a new environment list.
char **newenv = new char* [entries];
if ((newenv = new char* [entries]) == NULL)
return NULL;
// Make a copy of the list. Don't forget the NULL that ends the list.
entries = 0;
while (envp[entries] != NULL) {
newenv[entries] = new char[strlen (envp[entries]) + 1];
strcpy (newenv[entries], envp[entries]);
++entries;
}
newenv[entries] = NULL;
return newenv;
}
/// RemoveEnv - Remove the specified environment variable from the environment
/// array.
///
/// Inputs:
/// name - The name of the variable to remove. It cannot be NULL.
/// envp - The array of environment variables. It cannot be NULL.
///
/// Notes:
/// This is mainly done because functions to remove items from the environment
/// are not available across all platforms. In particular, Solaris does not
/// seem to have an unsetenv() function or a setenv() function (or they are
/// undocumented if they do exist).
///
static void RemoveEnv(const char * name, char ** const envp) {
for (unsigned index=0; envp[index] != NULL; index++) {
// Find the first equals sign in the array and make it an EOS character.
char *p = strchr (envp[index], '=');
if (p == NULL)
continue;
else
*p = '\0';
// Compare the two strings. If they are equal, zap this string.
// Otherwise, restore it.
if (!strcmp(name, envp[index]))
*envp[index] = '\0';
else
*p = '=';
}
return;
}
/// GenerateBitcode - generates a bitcode file from the module provided
void GenerateBitcode(Module* M, const std::string& FileName) {
if (Verbose)
outs() << "Generating Bitcode To " << FileName << '\n';
// Create the output file.
std::string ErrorInfo;
raw_fd_ostream Out(FileName.c_str(), /*Binary=*/true, /*Force=*/true,
ErrorInfo);
if (!ErrorInfo.empty())
PrintAndExit(ErrorInfo);
// Ensure that the bitcode file gets removed from the disk if we get a
// terminating signal.
sys::RemoveFileOnSignal(sys::Path(FileName));
// Write it out
WriteBitcodeToFile(M, Out);
// Close the bitcode file.
Out.close();
}
/// GenerateAssembly - generates a native assembly language source file from the
/// specified bitcode file.
///
/// Inputs:
/// InputFilename - The name of the input bitcode file.
/// OutputFilename - The name of the file to generate.
/// llc - The pathname to use for LLC.
/// envp - The environment to use when running LLC.
///
/// Return non-zero value on error.
///
static int GenerateAssembly(const std::string &OutputFilename,
const std::string &InputFilename,
const sys::Path &llc,
std::string &ErrMsg ) {
// Run LLC to convert the bitcode file into assembly code.
std::vector<const char*> args;
args.push_back(llc.c_str());
// We will use GCC to assemble the program so set the assembly syntax to AT&T,
// regardless of what the target in the bitcode file is.
args.push_back("-x86-asm-syntax=att");
args.push_back("-f");
args.push_back("-o");
args.push_back(OutputFilename.c_str());
args.push_back(InputFilename.c_str());
args.push_back(0);
if (Verbose) {
outs() << "Generating Assembly With: \n";
PrintCommand(args);
}
return sys::Program::ExecuteAndWait(llc, &args[0], 0, 0, 0, 0, &ErrMsg);
}
/// GenerateCFile - generates a C source file from the specified bitcode file.
static int GenerateCFile(const std::string &OutputFile,
const std::string &InputFile,
const sys::Path &llc,
std::string& ErrMsg) {
// Run LLC to convert the bitcode file into C.
std::vector<const char*> args;
args.push_back(llc.c_str());
args.push_back("-march=c");
args.push_back("-f");
args.push_back("-o");
args.push_back(OutputFile.c_str());
args.push_back(InputFile.c_str());
args.push_back(0);
if (Verbose) {
outs() << "Generating C Source With: \n";
PrintCommand(args);
}
return sys::Program::ExecuteAndWait(llc, &args[0], 0, 0, 0, 0, &ErrMsg);
}
/// GenerateNative - generates a native object file from the
/// specified bitcode file.
///
/// Inputs:
/// InputFilename - The name of the input bitcode file.
/// OutputFilename - The name of the file to generate.
/// NativeLinkItems - The native libraries, files, code with which to link
/// LibPaths - The list of directories in which to find libraries.
/// FrameworksPaths - The list of directories in which to find frameworks.
/// Frameworks - The list of frameworks (dynamic 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.
///
static int GenerateNative(const std::string &OutputFilename,
const std::string &InputFilename,
const Linker::ItemList &LinkItems,
const sys::Path &gcc, char ** const envp,
std::string& ErrMsg) {
// 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);
// 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.
std::vector<std::string> args;
args.push_back(gcc.c_str());
args.push_back("-fno-strict-aliasing");
args.push_back("-O3");
args.push_back("-o");
args.push_back(OutputFilename);
args.push_back(InputFilename);
// Add in the library and framework paths
for (unsigned index = 0; index < LibPaths.size(); index++) {
args.push_back("-L" + LibPaths[index]);
}
for (unsigned index = 0; index < FrameworkPaths.size(); index++) {
args.push_back("-F" + FrameworkPaths[index]);
}
// Add the requested options
for (unsigned index = 0; index < XLinker.size(); index++)
args.push_back(XLinker[index]);
// Add in the libraries to link.
for (unsigned index = 0; index < LinkItems.size(); index++)
if (LinkItems[index].first != "crtend") {
if (LinkItems[index].second)
args.push_back("-l" + LinkItems[index].first);
else
args.push_back(LinkItems[index].first);
}
// Add in frameworks to link.
for (unsigned index = 0; index < Frameworks.size(); index++) {
args.push_back("-framework");
args.push_back(Frameworks[index]);
}
// Now that "args" owns all the std::strings for the arguments, call the c_str
// method to get the underlying string array. We do this game so that the
// std::string array is guaranteed to outlive the const char* array.
std::vector<const char *> Args;
for (unsigned i = 0, e = args.size(); i != e; ++i)
Args.push_back(args[i].c_str());
Args.push_back(0);
if (Verbose) {
outs() << "Generating Native Executable With:\n";
PrintCommand(Args);
}
// Run the compiler to assembly and link together the program.
int R = sys::Program::ExecuteAndWait(
gcc, &Args[0], (const char**)clean_env, 0, 0, 0, &ErrMsg);
delete [] clean_env;
return R;
}
/// EmitShellScript - Output the wrapper file that invokes the JIT on the LLVM
/// bitcode file for the program.
static void EmitShellScript(char **argv) {
if (Verbose)
outs() << "Emitting Shell Script\n";
#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 ErrMsg;
sys::Path llvmstub = FindExecutable("llvm-stub.exe", argv[0]);
if (llvmstub.isEmpty())
PrintAndExit("Could not find llvm-stub.exe executable!");
if (0 != sys::CopyFile(sys::Path(OutputFilename), llvmstub, &ErrMsg))
PrintAndExit(ErrMsg);
return;
#endif
// Output the script to start the program...
std::string ErrorInfo;
raw_fd_ostream Out2(OutputFilename.c_str(), /*Binary=*/false, /*Force=*/true,
ErrorInfo);
if (!ErrorInfo.empty())
PrintAndExit(ErrorInfo);
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) {
// try explicit -L arguments first:
sys::Path FullLibraryPath;
for (cl::list<std::string>::const_iterator P = LibPaths.begin(),
E = LibPaths.end(); P != E; ++P) {
FullLibraryPath = *P;
FullLibraryPath.appendComponent("lib" + *i);
FullLibraryPath.appendSuffix(&(LTDL_SHLIB_EXT[1]));
if (!FullLibraryPath.isEmpty()) {
if (!FullLibraryPath.isDynamicLibrary()) {
// Not a native shared library; mark as invalid
FullLibraryPath = sys::Path();
} else break;
}
}
if (FullLibraryPath.isEmpty())
FullLibraryPath = sys::Path::FindLibrary(*i);
if (!FullLibraryPath.isEmpty())
Out2 << " -load=" << FullLibraryPath.toString() << " \\\n";
}
Out2 << " " << BitcodeOutputFilename << " ${1+\"$@\"}\n";
Out2.close();
}
// BuildLinkItems -- This function generates a LinkItemList for the LinkItems
// linker function by combining the Files and Libraries in the order they were
// declared on the command line.
static void BuildLinkItems(
Linker::ItemList& Items,
const cl::list<std::string>& Files,
const cl::list<std::string>& Libraries) {
// Build the list of linkage items for LinkItems.
cl::list<std::string>::const_iterator fileIt = Files.begin();
cl::list<std::string>::const_iterator libIt = Libraries.begin();
int libPos = -1, filePos = -1;
while ( libIt != Libraries.end() || fileIt != Files.end() ) {
if (libIt != Libraries.end())
libPos = Libraries.getPosition(libIt - Libraries.begin());
else
libPos = -1;
if (fileIt != Files.end())
filePos = Files.getPosition(fileIt - Files.begin());
else
filePos = -1;
if (filePos != -1 && (libPos == -1 || filePos < libPos)) {
// Add a source file
Items.push_back(std::make_pair(*fileIt++, false));
} else if (libPos != -1 && (filePos == -1 || libPos < filePos)) {
// Add a library
Items.push_back(std::make_pair(*libIt++, true));
}
}
}
// Rightly this should go in a header file but it just seems such a waste.
namespace llvm {
extern void Optimize(Module*);
}
int main(int argc, char **argv, char **envp) {
// Print a stack trace if we signal out.
sys::PrintStackTraceOnErrorSignal();
PrettyStackTraceProgram X(argc, argv);
LLVMContext &Context = getGlobalContext();
llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
try {
// Initial global variable above for convenience printing of program name.
progname = sys::Path(argv[0]).getBasename();
// Parse the command line options
cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
// Construct a Linker (now that Verbose is set)
Linker TheLinker(progname, OutputFilename, Context, Verbose);
// Keep track of the native link items (versus the bitcode items)
Linker::ItemList NativeLinkItems;
// Add library paths to the linker
TheLinker.addPaths(LibPaths);
TheLinker.addSystemPaths();
// Remove any consecutive duplicates of the same library...
Libraries.erase(std::unique(Libraries.begin(), Libraries.end()),
Libraries.end());
if (LinkAsLibrary) {
std::vector<sys::Path> Files;
for (unsigned i = 0; i < InputFilenames.size(); ++i )
Files.push_back(sys::Path(InputFilenames[i]));
if (TheLinker.LinkInFiles(Files))
return 1; // Error already printed
// The libraries aren't linked in but are noted as "dependent" in the
// module.
for (cl::list<std::string>::const_iterator I = Libraries.begin(),
E = Libraries.end(); I != E ; ++I) {
TheLinker.getModule()->addLibrary(*I);
}
} else {
// Build a list of the items from our command line
Linker::ItemList Items;
BuildLinkItems(Items, InputFilenames, Libraries);
// Link all the items together
if (TheLinker.LinkInItems(Items, NativeLinkItems) )
return 1; // Error already printed
}
std::auto_ptr<Module> Composite(TheLinker.releaseModule());
// Optimize the module
Optimize(Composite.get());
#if defined(_WIN32) || defined(__CYGWIN__)
if (!LinkAsLibrary) {
// Default to "a.exe" instead of "a.out".
if (OutputFilename.getNumOccurrences() == 0)
OutputFilename = "a.exe";
// If there is no suffix add an "exe" one.
sys::Path ExeFile( OutputFilename );
if (ExeFile.getSuffix() == "") {
ExeFile.appendSuffix("exe");
OutputFilename = ExeFile.toString();
}
}
#endif
// Generate the bitcode for the optimized module.
// If -b wasn't specified, use the name specified
// with -o to construct BitcodeOutputFilename.
if (BitcodeOutputFilename.empty()) {
BitcodeOutputFilename = OutputFilename;
if (!LinkAsLibrary) BitcodeOutputFilename += ".bc";
}
GenerateBitcode(Composite.get(), BitcodeOutputFilename);
// 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 run a post-link optimization, run it now.
if (!PostLinkOpts.empty()) {
std::vector<std::string> opts = PostLinkOpts;
for (std::vector<std::string>::iterator I = opts.begin(),
E = opts.end(); I != E; ++I) {
sys::Path prog(*I);
if (!prog.canExecute()) {
prog = sys::Program::FindProgramByName(*I);
if (prog.isEmpty())
PrintAndExit(std::string("Optimization program '") + *I +
"' is not found or not executable.");
}
// Get the program arguments
sys::Path tmp_output("opt_result");
std::string ErrMsg;
if (tmp_output.createTemporaryFileOnDisk(true, &ErrMsg))
PrintAndExit(ErrMsg);
const char* args[4];
args[0] = I->c_str();
args[1] = BitcodeOutputFilename.c_str();
args[2] = tmp_output.c_str();
args[3] = 0;
if (0 == sys::Program::ExecuteAndWait(prog, args, 0,0,0,0, &ErrMsg)) {
if (tmp_output.isBitcodeFile() || tmp_output.isBitcodeFile()) {
sys::Path target(BitcodeOutputFilename);
target.eraseFromDisk();
if (tmp_output.renamePathOnDisk(target, &ErrMsg))
PrintAndExit(ErrMsg, 2);
} else
PrintAndExit("Post-link optimization output is not bitcode");
} else {
PrintAndExit(ErrMsg);
}
}
}
// If the user wants to generate a native executable, compile it from the
// bitcode file.
//
// Otherwise, create a script that will run the bitcode through the JIT.
if (Native) {
// Name of the Assembly Language output file
sys::Path AssemblyFile ( OutputFilename);
AssemblyFile.appendSuffix("s");
// Mark the output files for removal if we get an interrupt.
sys::RemoveFileOnSignal(AssemblyFile);
sys::RemoveFileOnSignal(sys::Path(OutputFilename));
// Determine the locations of the llc and gcc programs.
sys::Path llc = FindExecutable("llc", argv[0]);
if (llc.isEmpty())
PrintAndExit("Failed to find llc");
sys::Path gcc = FindExecutable("gcc", argv[0]);
if (gcc.isEmpty())
PrintAndExit("Failed to find gcc");
// Generate an assembly language file for the bitcode.
std::string ErrMsg;
if (0 != GenerateAssembly(AssemblyFile.toString(), BitcodeOutputFilename,
llc, ErrMsg))
PrintAndExit(ErrMsg);
if (0 != GenerateNative(OutputFilename, AssemblyFile.toString(),
NativeLinkItems, gcc, envp, ErrMsg))
PrintAndExit(ErrMsg);
// Remove the assembly language file.
AssemblyFile.eraseFromDisk();
} else if (NativeCBE) {
sys::Path CFile (OutputFilename);
CFile.appendSuffix("cbe.c");
// Mark the output files for removal if we get an interrupt.
sys::RemoveFileOnSignal(CFile);
sys::RemoveFileOnSignal(sys::Path(OutputFilename));
// Determine the locations of the llc and gcc programs.
sys::Path llc = FindExecutable("llc", argv[0]);
if (llc.isEmpty())
PrintAndExit("Failed to find llc");
sys::Path gcc = FindExecutable("gcc", argv[0]);
if (gcc.isEmpty())
PrintAndExit("Failed to find gcc");
// Generate an assembly language file for the bitcode.
std::string ErrMsg;
if (0 != GenerateCFile(
CFile.toString(), BitcodeOutputFilename, llc, ErrMsg))
PrintAndExit(ErrMsg);
if (0 != GenerateNative(OutputFilename, CFile.toString(),
NativeLinkItems, gcc, envp, ErrMsg))
PrintAndExit(ErrMsg);
// Remove the assembly language file.
CFile.eraseFromDisk();
} else {
EmitShellScript(argv);
}
// Make the script executable...
std::string ErrMsg;
if (sys::Path(OutputFilename).makeExecutableOnDisk(&ErrMsg))
PrintAndExit(ErrMsg);
// Make the bitcode file readable and directly executable in LLEE as well
if (sys::Path(BitcodeOutputFilename).makeExecutableOnDisk(&ErrMsg))
PrintAndExit(ErrMsg);
if (sys::Path(BitcodeOutputFilename).makeReadableOnDisk(&ErrMsg))
PrintAndExit(ErrMsg);
}
} catch (const std::string& msg) {
PrintAndExit(msg,2);
} catch (...) {
PrintAndExit("Unexpected unknown exception occurred.", 2);
}
// Graceful exit
return 0;
}
Reference in New Issue View Git Blame Copy Permalink