llvm-6502/tools/llvm-ld/llvm-ld.cpp
Reid Spencer a229c5cce7 Final Changes For PR495:
This chagne just renames some sys::Path methods to ensure they are not
misused. The Path documentation now divides methods into two dimensions:
Path/Disk and accessor/mutator. Path accessors and mutators only operate
on the Path object itself without making any disk accesses. Disk accessors
and mutators will also access or modify the file system. Because of the
potentially destructive nature of disk mutators, it was decided that all
such methods should end in the work "Disk" to ensure the user recognizes
that the change will occur on the file system. This patch makes that
change. The method name changes are:

makeReadable        -> makeReadableOnDisk
makeWriteable       -> makeWriteableOnDisk
makeExecutable      -> makeExecutableOnDisk
setStatusInfo       -> setStatusInfoOnDisk
createDirectory     -> createDirectoryOnDisk
createFile          -> createFileOnDisk
createTemporaryFile -> createTemporaryFileOnDisk
destroy             -> eraseFromDisk
rename              -> renamePathOnDisk

These changes pass the Linux Deja Gnu tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22354 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-08 03:08:58 +00:00

530 lines
19 KiB
C++

//===- 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/Linker.h"
#include "llvm/System/Program.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Bytecode/Reader.h"
#include "llvm/Bytecode/Writer.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetMachineRegistry.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileUtilities.h"
#include "llvm/Support/SystemUtils.h"
#include "llvm/System/Signals.h"
#include <fstream>
#include <iostream>
#include <memory>
using namespace llvm;
// Input/Output Options
static cl::list<std::string> InputFilenames(cl::Positional, cl::OneOrMore,
cl::desc("<input bytecode files>"));
static cl::opt<std::string> OutputFilename("o", cl::init("a.out"),
cl::desc("Override 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> Libraries("l", cl::Prefix,
cl::desc("Specify libraries to link to"),
cl::value_desc("library prefix"));
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<const TargetMachineRegistry::Entry*, false, TargetNameParser>
MachineArch("march", cl::desc("Architecture to generate assembly for:"));
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::opt<bool>DisableCompression("disable-compression",cl::init(false),
cl::desc("Disable writing of compressed bytecode files"));
// Compatibility options that are ignored but supported by 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"));
/// This is just for convenience so it doesn't have to be passed around
/// everywhere.
static std::string progname;
/// 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 std::string &Message) {
std::cerr << progname << ": " << Message << "\n";
return 1;
}
/// 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;
}
/// GenerateBytecode - generates a bytecode file from the module provided
void GenerateBytecode(Module* M, const std::string& FileName) {
// Create the output file.
std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
std::ios::binary;
std::ofstream Out(FileName.c_str(), io_mode);
if (!Out.good()) {
PrintAndReturn("error opening '" + FileName + "' for writing!");
return;
}
// Ensure that the bytecode file gets removed from the disk if we get a
// terminating signal.
sys::RemoveFileOnSignal(sys::Path(FileName));
// Write it out
WriteBytecodeToFile(M, Out, !DisableCompression);
// Close the bytecode file.
Out.close();
}
/// 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.
///
/// Return non-zero value on error.
///
static int GenerateAssembly(const std::string &OutputFilename,
const std::string &InputFilename,
const sys::Path &llc) {
// Run LLC to convert the bytecode file into assembly code.
std::vector<const char*> args;
args.push_back(llc.c_str());
args.push_back("-f");
args.push_back("-o");
args.push_back(OutputFilename.c_str());
args.push_back(InputFilename.c_str());
args.push_back(0);
return sys::Program::ExecuteAndWait(llc,&args[0]);
}
/// GenerateAssembly - generates a native assembly language source file from the
/// specified bytecode file.
static int GenerateCFile(const std::string &OutputFile,
const std::string &InputFile,
const sys::Path &llc) {
// Run LLC to convert the bytecode 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);
return sys::Program::ExecuteAndWait(llc, &args[0]);
}
/// 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.
///
static int GenerateNative(const std::string &OutputFilename,
const std::string &InputFilename,
const std::vector<std::string> &Libraries,
const sys::Path &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);
// 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<const char*> 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.c_str());
args.push_back(InputFilename.c_str());
// Add in the libraries to link.
for (unsigned index = 0; index < Libraries.size(); index++)
if (Libraries[index] != "crtend") {
args.push_back("-l");
args.push_back(Libraries[index].c_str());
}
args.push_back(0);
// Run the compiler to assembly and link together the program.
return sys::Program::ExecuteAndWait(gcc, &args[0], (const char**)clean_env);
}
/// 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.
sys::Path llvmstub = FindExecutable("llvm-stub.exe", argv[0]);
if (llvmstub.isEmpty()) {
std::cerr << "Could not find llvm-stub.exe executable!\n";
exit(1);
}
sys::CopyFile(sys::Path(OutputFilename), llvmstub);
return;
#endif
// Output the script to start the program...
std::ofstream Out2(OutputFilename.c_str());
if (!Out2.good())
exit(PrintAndReturn("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) {
sys::Path FullLibraryPath = sys::Path::FindLibrary(*i);
if (!FullLibraryPath.isEmpty() && FullLibraryPath.isDynamicLibrary())
Out2 << " -load=" << FullLibraryPath.toString() << " \\\n";
}
Out2 << " $0.bc ${1+\"$@\"}\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) {
try {
// Initial global variable above for convenience printing of program name.
progname = sys::Path(argv[0]).getBasename();
Linker TheLinker(progname, Verbose);
// Set up the library paths for the Linker
TheLinker.addPaths(LibPaths);
TheLinker.addSystemPaths();
// Parse the command line options
cl::ParseCommandLineOptions(argc, argv, " llvm linker\n");
sys::PrintStackTraceOnErrorSignal();
// 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) )
return 1;
}
std::auto_ptr<Module> Composite(TheLinker.releaseModule());
// Optimize the module
Optimize(Composite.get());
// Generate the bytecode for the optimized module.
std::string RealBytecodeOutput = OutputFilename;
if (!LinkAsLibrary) RealBytecodeOutput += ".bc";
GenerateBytecode(Composite.get(), RealBytecodeOutput);
// 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
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())
return PrintAndReturn("Failed to find llc");
sys::Path gcc = FindExecutable("gcc", argv[0]);
if (gcc.isEmpty())
return PrintAndReturn("Failed to find gcc");
// Generate an assembly language file for the bytecode.
if (Verbose) std::cout << "Generating Assembly Code\n";
GenerateAssembly(AssemblyFile.toString(), RealBytecodeOutput, llc);
if (Verbose) std::cout << "Generating Native Code\n";
GenerateNative(OutputFilename, AssemblyFile.toString(), Libraries,
gcc, envp);
// 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())
return PrintAndReturn("Failed to find llc");
sys::Path gcc = FindExecutable("gcc", argv[0]);
if (gcc.isEmpty())
return PrintAndReturn("Failed to find gcc");
// Generate an assembly language file for the bytecode.
if (Verbose) std::cout << "Generating Assembly Code\n";
GenerateCFile(CFile.toString(), RealBytecodeOutput, llc);
if (Verbose) std::cout << "Generating Native Code\n";
GenerateNative(OutputFilename, CFile.toString(), Libraries, gcc, envp);
// Remove the assembly language file.
CFile.eraseFromDisk();
} else {
EmitShellScript(argv);
}
// Make the script executable...
sys::Path(OutputFilename).makeExecutableOnDisk();
// Make the bytecode file readable and directly executable in LLEE as well
sys::Path(RealBytecodeOutput).makeExecutableOnDisk();
sys::Path(RealBytecodeOutput).makeReadableOnDisk();
}
return 0;
} catch (const std::string& msg) {
std::cerr << argv[0] << ": " << msg << "\n";
} catch (...) {
std::cerr << argv[0] << ": Unexpected unknown exception occurred.\n";
}
return 1;
}