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-rw-r--r--lib/Linker/LinkArchives.cpp601
-rw-r--r--tools/gccld/GenerateCode.cpp101
-rw-r--r--tools/gccld/Linker.cpp601
-rw-r--r--tools/gccld/gccld.cpp362
-rw-r--r--tools/gccld/util.cpp287
-rw-r--r--tools/gccld/util.h31
6 files changed, 1416 insertions, 567 deletions
diff --git a/lib/Linker/LinkArchives.cpp b/lib/Linker/LinkArchives.cpp
new file mode 100644
index 0000000000..d72c485330
--- /dev/null
+++ b/lib/Linker/LinkArchives.cpp
@@ -0,0 +1,601 @@
+//===- gccld.cpp - LLVM 'ld' compatible linker ----------------------------===//
+//
+// 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/Transforms/Utils/Linker.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 "Support/FileUtilities.h"
+#include "Support/SystemUtils.h"
+#include "Support/CommandLine.h"
+#include "Support/Signals.h"
+#include "Config/stdlib.h"
+#include "gccld.h"
+
+#include <fstream>
+#include <memory>
+#include <set>
+#include <algorithm>
+
+//
+// Function: FileExists ()
+//
+// Description:
+// Determine if the specified filename exists and is readable.
+//
+// Inputs:
+// FN - The name of the file.
+//
+// Outputs:
+// None.
+//
+// Return Value:
+// TRUE - The file exists and is readable.
+// FALSE - The file does not exist or is unreadable.
+//
+static inline bool
+FileExists(const std::string &FN)
+{
+ return access(FN.c_str(), R_OK | F_OK) != -1;
+}
+
+//
+// Function: IsArchive ()
+//
+// Description:
+// Determine if the specified file is an ar archive. It determines this by
+// checking the magic string at the beginning of the file.
+//
+// Inputs:
+// filename - A C++ string containing the name of the file.
+//
+// Outputs:
+// None.
+//
+// Return value:
+// TRUE - The file is an archive.
+// FALSE - The file is not an archive.
+//
+static inline bool
+IsArchive (const std::string &filename)
+{
+ std::string ArchiveMagic("!<arch>\012");
+ char buf[1 + ArchiveMagic.size()];
+
+ std::ifstream f(filename.c_str());
+ f.read(buf, ArchiveMagic.size());
+ buf[ArchiveMagic.size()] = '\0';
+ return ArchiveMagic == buf;
+}
+
+//
+// Function: FindLib ()
+//
+// Description:
+// This function locates a particular library. It will prepend and append
+// various directories, prefixes, and suffixes until it can find the library.
+//
+// Inputs:
+// Filename - Name of the file to find.
+// Paths - List of directories to search.
+//
+// Outputs:
+// None.
+//
+// Return value:
+// The name of the file is returned.
+// If the file is not found, an empty string is returned.
+//
+static std::string
+FindLib (const std::string & Filename, const std::vector<std::string> & Paths)
+{
+ //
+ // Determine if the pathname can be found as it stands.
+ //
+ if (FileExists (Filename))
+ {
+ return Filename;
+ }
+
+ //
+ // If that doesn't work, convert the name into a library name.
+ //
+ std::string LibName = "lib" + Filename;
+
+ //
+ // Iterate over the directories in Paths to see if we can find the library
+ // there.
+ //
+ for (unsigned Index = 0; Index != Paths.size(); ++Index)
+ {
+ std::string Directory = Paths[Index] + "/";
+
+ if (FileExists (Directory + LibName + ".bc"))
+ {
+ return Directory + LibName + ".bc";
+ }
+
+ if (FileExists (Directory + LibName + ".so"))
+ {
+ return Directory + LibName + ".so";
+ }
+
+ if (FileExists (Directory + LibName + ".a"))
+ {
+ return Directory + LibName + ".a";
+ }
+ }
+
+ //
+ // One last hope: Check LLVM_LIB_SEARCH_PATH.
+ //
+ char *SearchPath = getenv("LLVM_LIB_SEARCH_PATH");
+ if (SearchPath == NULL)
+ {
+ return std::string();
+ }
+
+ LibName = std::string(SearchPath) + "/" + LibName;
+ if (FileExists (LibName))
+ {
+ return LibName;
+ }
+
+ return std::string();
+}
+
+//
+// Function: GetAllDefinedSymbols ()
+//
+// Description:
+// Find all of the defined symbols in the specified module.
+//
+// Inputs:
+// M - The module in which to find defined symbols.
+//
+// Outputs:
+// DefinedSymbols - A set of C++ strings that will contain the name of all
+// defined symbols.
+//
+// Return value:
+// None.
+//
+void
+GetAllDefinedSymbols (Module *M, std::set<std::string> &DefinedSymbols)
+{
+ for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+ if (I->hasName() && !I->isExternal() && !I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+ for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
+ if (I->hasName() && !I->isExternal() && !I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+}
+
+//
+// Function: GetAllUndefinedSymbols ()
+//
+// Description:
+// This calculates the set of undefined symbols that still exist in an LLVM
+// module. This is a bit tricky because there may be two symbols with the
+// same name but different LLVM types that will be resolved to each other but
+// aren't currently (thus we need to treat it as resolved).
+//
+// Inputs:
+// M - The module in which to find undefined symbols.
+//
+// Outputs:
+// UndefinedSymbols - A set of C++ strings containing the name of all
+// undefined symbols.
+//
+// Return value:
+// None.
+//
+void
+GetAllUndefinedSymbols(Module *M, std::set<std::string> &UndefinedSymbols)
+{
+ std::set<std::string> DefinedSymbols;
+ UndefinedSymbols.clear(); // Start out empty
+
+ for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+ if (I->hasName()) {
+ if (I->isExternal())
+ UndefinedSymbols.insert(I->getName());
+ else if (!I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+ }
+ for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
+ if (I->hasName()) {
+ if (I->isExternal())
+ UndefinedSymbols.insert(I->getName());
+ else if (!I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+ }
+
+ // Prune out any defined symbols from the undefined symbols set...
+ for (std::set<std::string>::iterator I = UndefinedSymbols.begin();
+ I != UndefinedSymbols.end(); )
+ if (DefinedSymbols.count(*I))
+ UndefinedSymbols.erase(I++); // This symbol really is defined!
+ else
+ ++I; // Keep this symbol in the undefined symbols list
+}
+
+
+//
+// Function: LoadObject ()
+//
+// Description:
+// Read the specified bytecode object file.
+//
+// Inputs:
+// FN - The name of the file to load.
+//
+// Outputs:
+// OutErrorMessage - The error message to give back to the caller.
+//
+// Return Value:
+// A pointer to a module represening the bytecode file is returned.
+// If an error occurs, the pointer is 0.
+//
+std::auto_ptr<Module>
+LoadObject (const std::string & FN, std::string &OutErrorMessage)
+{
+ std::string ErrorMessage;
+ Module *Result = ParseBytecodeFile(FN, &ErrorMessage);
+ if (Result) return std::auto_ptr<Module>(Result);
+
+ OutErrorMessage = "Bytecode file '" + FN + "' corrupt!";
+ if (ErrorMessage.size()) OutErrorMessage += ": " + ErrorMessage;
+ return std::auto_ptr<Module>();
+}
+
+//
+// Function: LinkInArchive ()
+//
+// Description:
+// This function will open an archive library and link in all objects which
+// provide symbols that are currently undefined.
+//
+// Inputs:
+// M - The module in which to link the archives.
+// Filename - The pathname of the archive.
+// Verbose - Flags whether verbose messages should be printed.
+//
+// Outputs:
+// ErrorMessage - A C++ string detailing what error occurred, if any.
+//
+// Return Value:
+// TRUE - An error occurred.
+// FALSE - No errors.
+//
+static bool
+LinkInArchive (Module * M,
+ const std::string & Filename,
+ std::string & ErrorMessage,
+ bool Verbose)
+{
+ //
+ // Find all of the symbols currently undefined in the bytecode program.
+ // If all the symbols are defined, the program is complete, and there is
+ // no reason to link in any archive files.
+ //
+ std::set<std::string> UndefinedSymbols;
+ GetAllUndefinedSymbols (M, UndefinedSymbols);
+ if (UndefinedSymbols.empty())
+ {
+ if (Verbose) std::cerr << " No symbols undefined, don't link library!\n";
+ return false; // No need to link anything in!
+ }
+
+ //
+ // Load in the archive objects.
+ //
+ if (Verbose) std::cerr << " Loading '" << Filename << "'\n";
+ std::vector<Module*> Objects;
+ if (ReadArchiveFile (Filename, Objects, &ErrorMessage))
+ {
+ return true;
+ }
+
+ //
+ // Figure out which symbols are defined by all of the modules in the archive.
+ //
+ std::vector<std::set<std::string> > DefinedSymbols;
+ DefinedSymbols.resize (Objects.size());
+ for (unsigned i = 0; i != Objects.size(); ++i)
+ {
+ GetAllDefinedSymbols(Objects[i], DefinedSymbols[i]);
+ }
+
+ // While we are linking in object files, loop.
+ bool Linked = true;
+ while (Linked)
+ {
+ Linked = false;
+
+ for (unsigned i = 0; i != Objects.size(); ++i) {
+ // Consider whether we need to link in this module... we only need to
+ // link it in if it defines some symbol which is so far undefined.
+ //
+ const std::set<std::string> &DefSymbols = DefinedSymbols[i];
+
+ bool ObjectRequired = false;
+ for (std::set<std::string>::iterator I = UndefinedSymbols.begin(),
+ E = UndefinedSymbols.end(); I != E; ++I)
+ if (DefSymbols.count(*I)) {
+ if (Verbose)
+ std::cerr << " Found object providing symbol '" << *I << "'...\n";
+ ObjectRequired = true;
+ break;
+ }
+
+ // We DO need to link this object into the program...
+ if (ObjectRequired) {
+ if (LinkModules(M, Objects[i], &ErrorMessage))
+ return true; // Couldn't link in the right object file...
+
+ // Since we have linked in this object, delete it from the list of
+ // objects to consider in this archive file.
+ std::swap(Objects[i], Objects.back());
+ std::swap(DefinedSymbols[i], DefinedSymbols.back());
+ Objects.pop_back();
+ DefinedSymbols.pop_back();
+ --i; // Do not skip an entry
+
+ // The undefined symbols set should have shrunk.
+ GetAllUndefinedSymbols(M, UndefinedSymbols);
+ Linked = true; // We have linked something in!
+ }
+ }
+ }
+
+ return false;
+}
+
+//
+// Function: LinkInFile ()
+//
+// Description:
+// This function will open an archive library and link in all objects which
+// provide symbols that are currently undefined.
+//
+// Inputs:
+// HeadModule - The module in which to link the archives.
+// Filename - The pathname of the archive.
+// Verbose - Flags whether verbose messages should be printed.
+//
+// Outputs:
+// ErrorMessage - A C++ string detailing what error occurred, if any.
+//
+// Return Value:
+// TRUE - An error occurred.
+// FALSE - No errors.
+//
+static bool
+LinkInFile (Module * HeadModule,
+ const std::string & Filename,
+ std::string & ErrorMessage,
+ bool Verbose)
+{
+ std::auto_ptr<Module> M(LoadObject(Filename, ErrorMessage));
+ if (M.get() == 0)
+ {
+ return true;
+ }
+
+ if (Verbose) std::cerr << "Linking in '" << Filename << "'\n";
+
+ return (LinkModules (HeadModule, M.get(), &ErrorMessage));
+}
+
+//
+// Function: LinkFiles ()
+//
+// Description:
+// This function takes a module and a list of files and links them all
+// together. It locates the file either in the current directory, as it's
+// absolute or relative pathname, or as a file somewhere in
+// LLVM_LIB_SEARCH_PATH.
+//
+// Inputs:
+// progname - The name of the program (infamous argv[0]).
+// HeadModule - The module under which all files will be linked.
+// Files - A vector of C++ strings indicating the LLVM bytecode filenames
+// to be linked. The names can refer to a mixture of pure LLVM
+// bytecode files and archive (ar) formatted files.
+// Verbose - Flags whether verbose output should be printed while linking.
+//
+// Outputs:
+// HeadModule - The module will have the specified LLVM bytecode files linked
+// in.
+//
+// Return value:
+// FALSE - No errors.
+// TRUE - Some error occurred.
+//
+bool
+LinkFiles (const char * progname,
+ Module * HeadModule,
+ const std::vector<std::string> & Files,
+ bool Verbose)
+{
+ // String in which to receive error messages.
+ std::string ErrorMessage;
+
+ // Full pathname of the file
+ std::string Pathname;
+
+ // Get the library search path from the environment
+ char *SearchPath = getenv("LLVM_LIB_SEARCH_PATH");
+
+ for (unsigned i = 1; i < Files.size(); ++i)
+ {
+ //
+ // Determine where this file lives.
+ //
+ if (FileExists (Files[i]))
+ {
+ Pathname = Files[i];
+ }
+ else
+ {
+ if (SearchPath == NULL)
+ {
+ std::cerr << "Cannot find " << Files[i];
+ return true;
+ }
+
+ Pathname = std::string(SearchPath)+"/"+Files[i];
+ if (!FileExists (Pathname))
+ {
+ std::cerr << "Cannot find " << Files[i];
+ return true;
+ }
+ }
+
+ //
+ // A user may specify an ar archive without -l, perhaps because it
+ // is not installed as a library. Detect that and link the library.
+ //
+ if (IsArchive(Pathname))
+ {
+ if (Verbose)
+ {
+ std::cerr << "Linking archive '" << Files[i] << "'\n";
+ }
+
+ if (LinkInArchive (HeadModule, Pathname, ErrorMessage, Verbose))
+ {
+ PrintAndReturn(progname, ErrorMessage,
+ ": Error linking in '" + Files[i] + "'");
+ return true;
+ }
+ }
+ else
+ {
+ if (Verbose)
+ {
+ std::cerr << "Linking file '" << Files[i] << "'\n";
+ }
+
+ if (LinkInFile (HeadModule, Pathname, ErrorMessage, Verbose))
+ {
+ PrintAndReturn(progname, ErrorMessage,
+ ": error linking in '" + Files[i] + "'");
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
+//
+// Function: LinkLibraries ()
+//
+// Description:
+// This function takes the specified library files and links them into the
+// main bytecode object file.
+//
+// Inputs:
+// progname - The name of the program (infamous argv[0]).
+// HeadModule - The module into which all necessary libraries will be linked.
+// Libraries - The list of libraries to link into the module.
+// LibPaths - The list of library paths in which to find libraries.
+// Verbose - Flags whether verbose messages should be printed.
+// Native - Flags whether native code is being generated.
+//
+// Outputs:
+// HeadModule - The module will have all necessary libraries linked in.
+//
+// Return value:
+// FALSE - No error.
+// TRUE - Error.
+//
+bool
+LinkLibraries (const char * progname,
+ Module * HeadModule,
+ const std::vector<std::string> & Libraries,
+ const std::vector<std::string> & LibPaths,
+ bool Verbose,
+ bool Native)
+{
+ // String in which to receive error messages.
+ std::string ErrorMessage;
+
+ for (unsigned i = 1; i < Libraries.size(); ++i)
+ {
+ //
+ // Determine where this library lives.
+ //
+ std::string Pathname = FindLib (Libraries[i], LibPaths);
+ if (Pathname.empty())
+ {
+ //
+ // If the pathname does not exist, then continue to the next one if
+ // we're doing a native link and give an error if we're doing a bytecode
+ // link.
+ //
+ if (Native)
+ {
+ continue;
+ }
+ else
+ {
+ PrintAndReturn (progname, "Cannot find " + Libraries[i]);
+ return true;
+ }
+ }
+
+ //
+ // A user may specify an ar archive without -l, perhaps because it
+ // is not installed as a library. Detect that and link the library.
+ //
+ if (IsArchive(Pathname))
+ {
+ if (Verbose)
+ {
+ std::cerr << "Linking archive '" << Libraries[i] << "'\n";
+ }
+
+ if (LinkInArchive (HeadModule, Pathname, ErrorMessage, Verbose))
+ {
+ PrintAndReturn(progname, ErrorMessage,
+ ": Error linking in '" + Libraries[i] + "'");
+ return true;
+ }
+ }
+ else
+ {
+ if (Verbose)
+ {
+ std::cerr << "Linking file '" << Libraries[i] << "'\n";
+ }
+
+ if (LinkInFile (HeadModule, Pathname, ErrorMessage, Verbose))
+ {
+ PrintAndReturn(progname, ErrorMessage,
+ ": error linking in '" + Libraries[i] + "'");
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
diff --git a/tools/gccld/GenerateCode.cpp b/tools/gccld/GenerateCode.cpp
index b9f7f3b8e1..09583df8d1 100644
--- a/tools/gccld/GenerateCode.cpp
+++ b/tools/gccld/GenerateCode.cpp
@@ -1,4 +1,4 @@
-//===- genexec.cpp - Functions for generating executable files ------------===//
+//===- gencode.cpp - Functions for generating executable files -----------===//
//
// This file contains functions for generating executable files once linking
// has finished. This includes generating a shell script to run the JIT or
@@ -14,11 +14,7 @@
#include "llvm/PassManager.h"
#include "llvm/Bytecode/WriteBytecodePass.h"
#include "Support/SystemUtils.h"
-#include "util.h"
-
-#include <fstream>
-#include <string>
-#include <vector>
+#include "gccld.h"
//
// Function: GenerateBytecode ()
@@ -43,7 +39,7 @@ int
GenerateBytecode (Module * M,
bool Strip,
bool Internalize,
- std::ofstream * Out)
+ 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.
@@ -106,7 +102,7 @@ GenerateBytecode (Module * M,
}
//
-// Function: generate_assembly ()
+// Function: GenerateAssembly ()
//
// Description:
// This function generates a native assembly language source file from the
@@ -126,10 +122,10 @@ GenerateBytecode (Module * M,
// 1 - Failure
//
int
-generate_assembly (std::string OutputFilename,
- std::string InputFilename,
- std::string llc,
- char ** const envp)
+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.
@@ -142,16 +138,12 @@ generate_assembly (std::string OutputFilename,
cmd[3] = OutputFilename.c_str();
cmd[4] = InputFilename.c_str();
cmd[5] = NULL;
- if ((ExecWait (cmd, envp)) == -1)
- {
- return 1;
- }
- return 0;
+ return (ExecWait (cmd, envp));
}
//
-// Function: generate_native ()
+// Function: GenerateNative ()
//
// Description:
// This function generates a native assembly language source file from the
@@ -161,6 +153,7 @@ generate_assembly (std::string OutputFilename,
// 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.
//
@@ -172,11 +165,12 @@ generate_assembly (std::string OutputFilename,
// 1 - Failure
//
int
-generate_native (std::string OutputFilename,
- std::string InputFilename,
- std::vector<std::string> Libraries,
- std::string gcc,
- char ** const envp)
+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
@@ -187,18 +181,18 @@ generate_native (std::string OutputFilename,
// However, when we invoke GCC below, we want it to use its normal
// configuration. Hence, we must sanitize it's environment.
//
- char ** clean_env = copy_env (envp);
+ char ** clean_env = CopyEnv (envp);
if (clean_env == NULL)
{
return 1;
}
- remove_env ("LIBRARY_PATH", clean_env);
- remove_env ("COLLECT_GCC_OPTIONS", clean_env);
- remove_env ("GCC_EXEC_PREFIX", clean_env);
- remove_env ("COMPILER_PATH", clean_env);
- remove_env ("COLLECT_GCC", clean_env);
+ 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);
- const char * cmd[8 + Libraries.size()];
+ std::vector<const char *> cmd;
//
// Run GCC to assemble and link the program into native code.
@@ -208,21 +202,44 @@ generate_native (std::string OutputFilename,
// and linker because we don't know where to put the _start symbol.
// GCC mysteriously knows how to do it.
//
- unsigned int index=0;
- cmd[index++] = gcc.c_str();
- cmd[index++] = "-o";
- cmd[index++] = OutputFilename.c_str();
- cmd[index++] = InputFilename.c_str();
- for (; (index - 4) < Libraries.size(); index++)
+ cmd.push_back (gcc.c_str());
+ cmd.push_back ("-o");
+ cmd.push_back (OutputFilename.c_str());
+ cmd.push_back (InputFilename.c_str());
+
+ //
+ // JTC:
+ // 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.
+ //
+#ifdef ndef
+ //
+ // Add in the library path options.
+ //
+ for (unsigned index=0; index < LibPaths.size(); index++)
{
- Libraries[index - 4] = "-l" + Libraries[index - 4];
- cmd[index] = Libraries[index-4].c_str();
+ cmd.push_back ("-L");
+ cmd.push_back (LibPaths[index].c_str());
}
- cmd[index++] = NULL;
- if ((ExecWait (cmd, clean_env)) == -1)
+#endif
+
+ //
+ // Add in the libraries to link.
+ //
+ std::vector<std::string> Libs (Libraries);
+ for (unsigned index = 0; index < Libs.size(); index++)
{
- return 1;
+ Libs[index] = "-l" + Libs[index];
+ cmd.push_back (Libs[index].c_str());
}
+ cmd.push_back (NULL);
- return 0;
+ //
+ // Run the compiler to assembly and link together the program.
+ //
+ return (ExecWait (&(cmd[0]), clean_env));
}
diff --git a/tools/gccld/Linker.cpp b/tools/gccld/Linker.cpp
new file mode 100644
index 0000000000..d72c485330
--- /dev/null
+++ b/tools/gccld/Linker.cpp
@@ -0,0 +1,601 @@
+//===- gccld.cpp - LLVM 'ld' compatible linker ----------------------------===//
+//
+// 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/Transforms/Utils/Linker.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 "Support/FileUtilities.h"
+#include "Support/SystemUtils.h"
+#include "Support/CommandLine.h"
+#include "Support/Signals.h"
+#include "Config/stdlib.h"
+#include "gccld.h"
+
+#include <fstream>
+#include <memory>
+#include <set>
+#include <algorithm>
+
+//
+// Function: FileExists ()
+//
+// Description:
+// Determine if the specified filename exists and is readable.
+//
+// Inputs:
+// FN - The name of the file.
+//
+// Outputs:
+// None.
+//
+// Return Value:
+// TRUE - The file exists and is readable.
+// FALSE - The file does not exist or is unreadable.
+//
+static inline bool
+FileExists(const std::string &FN)
+{
+ return access(FN.c_str(), R_OK | F_OK) != -1;
+}
+
+//
+// Function: IsArchive ()
+//
+// Description:
+// Determine if the specified file is an ar archive. It determines this by
+// checking the magic string at the beginning of the file.
+//
+// Inputs:
+// filename - A C++ string containing the name of the file.
+//
+// Outputs:
+// None.
+//
+// Return value:
+// TRUE - The file is an archive.
+// FALSE - The file is not an archive.
+//
+static inline bool
+IsArchive (const std::string &filename)
+{
+ std::string ArchiveMagic("!<arch>\012");
+ char buf[1 + ArchiveMagic.size()];
+
+ std::ifstream f(filename.c_str());
+ f.read(buf, ArchiveMagic.size());
+ buf[ArchiveMagic.size()] = '\0';
+ return ArchiveMagic == buf;
+}
+
+//
+// Function: FindLib ()
+//
+// Description:
+// This function locates a particular library. It will prepend and append
+// various directories, prefixes, and suffixes until it can find the library.
+//
+// Inputs:
+// Filename - Name of the file to find.
+// Paths - List of directories to search.
+//
+// Outputs:
+// None.
+//
+// Return value:
+// The name of the file is returned.
+// If the file is not found, an empty string is returned.
+//
+static std::string
+FindLib (const std::string & Filename, const std::vector<std::string> & Paths)
+{
+ //
+ // Determine if the pathname can be found as it stands.
+ //
+ if (FileExists (Filename))
+ {
+ return Filename;
+ }
+
+ //
+ // If that doesn't work, convert the name into a library name.
+ //
+ std::string LibName = "lib" + Filename;
+
+ //
+ // Iterate over the directories in Paths to see if we can find the library
+ // there.
+ //
+ for (unsigned Index = 0; Index != Paths.size(); ++Index)
+ {
+ std::string Directory = Paths[Index] + "/";
+
+ if (FileExists (Directory + LibName + ".bc"))
+ {
+ return Directory + LibName + ".bc";
+ }
+
+ if (FileExists (Directory + LibName + ".so"))
+ {
+ return Directory + LibName + ".so";
+ }
+
+ if (FileExists (Directory + LibName + ".a"))
+ {
+ return Directory + LibName + ".a";
+ }
+ }
+
+ //
+ // One last hope: Check LLVM_LIB_SEARCH_PATH.
+ //
+ char *SearchPath = getenv("LLVM_LIB_SEARCH_PATH");
+ if (SearchPath == NULL)
+ {
+ return std::string();
+ }
+
+ LibName = std::string(SearchPath) + "/" + LibName;
+ if (FileExists (LibName))
+ {
+ return LibName;
+ }
+
+ return std::string();
+}
+
+//
+// Function: GetAllDefinedSymbols ()
+//
+// Description:
+// Find all of the defined symbols in the specified module.
+//
+// Inputs:
+// M - The module in which to find defined symbols.
+//
+// Outputs:
+// DefinedSymbols - A set of C++ strings that will contain the name of all
+// defined symbols.
+//
+// Return value:
+// None.
+//
+void
+GetAllDefinedSymbols (Module *M, std::set<std::string> &DefinedSymbols)
+{
+ for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+ if (I->hasName() && !I->isExternal() && !I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+ for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
+ if (I->hasName() && !I->isExternal() && !I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+}
+
+//
+// Function: GetAllUndefinedSymbols ()
+//
+// Description:
+// This calculates the set of undefined symbols that still exist in an LLVM
+// module. This is a bit tricky because there may be two symbols with the
+// same name but different LLVM types that will be resolved to each other but
+// aren't currently (thus we need to treat it as resolved).
+//
+// Inputs:
+// M - The module in which to find undefined symbols.
+//
+// Outputs:
+// UndefinedSymbols - A set of C++ strings containing the name of all
+// undefined symbols.
+//
+// Return value:
+// None.
+//
+void
+GetAllUndefinedSymbols(Module *M, std::set<std::string> &UndefinedSymbols)
+{
+ std::set<std::string> DefinedSymbols;
+ UndefinedSymbols.clear(); // Start out empty
+
+ for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+ if (I->hasName()) {
+ if (I->isExternal())
+ UndefinedSymbols.insert(I->getName());
+ else if (!I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+ }
+ for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
+ if (I->hasName()) {
+ if (I->isExternal())
+ UndefinedSymbols.insert(I->getName());
+ else if (!I->hasInternalLinkage())
+ DefinedSymbols.insert(I->getName());
+ }
+
+ // Prune out any defined symbols from the undefined symbols set...
+ for (std::set<std::string>::iterator I = UndefinedSymbols.begin();
+ I != UndefinedSymbols.end(); )
+ if (DefinedSymbols.count(*I))
+ UndefinedSymbols.erase(I++); // This symbol really is defined!
+ else
+ ++I; // Keep this symbol in the undefined symbols list
+}
+
+
+//
+// Function: LoadObject ()
+//
+// Description:
+// Read the specified bytecode object file.
+//
+// Inputs:
+// FN - The name of the file to load.
+//
+// Outputs:
+// OutErrorMessage - The error message to give back to the caller.
+//
+// Return Value:
+// A pointer to a module represening the bytecode file is returned.
+// If an error occurs, the pointer is 0.
+//
+std::auto_ptr<Module>
+LoadObject (const std::string & FN, std::string &OutErrorMessage)
+{
+ std::string ErrorMessage;
+ Module *Result = ParseBytecodeFile(FN, &ErrorMessage);
+ if (Result) return std::auto_ptr<Module>(Result);
+
+ OutErrorMessage = "Bytecode file '" + FN + "' corrupt!";
+ if (ErrorMessage.size()) OutErrorMessage += ": " + ErrorMessage;
+ return std::auto_ptr<Module>();
+}
+
+//
+// Function: LinkInArchive ()
+//
+// Description:
+// This function will open an archive library and link in all objects which
+// provide symbols that are currently undefined.
+//
+// Inputs:
+// M - The module in which to link the archives.
+// Filename - The pathname of the archive.
+// Verbose - Flags whether verbose messages should be printed.
+//
+// Outputs:
+// ErrorMessage - A C++ string detailing what error occurred, if any.
+//
+// Return Value:
+// TRUE - An error occurred.
+// FALSE - No errors.
+//
+static bool
+LinkInArchive (Module * M,
+ const std::string & Filename,
+ std::string & ErrorMessage,
+ bool Verbose)
+{
+ //
+ // Find all of the symbols currently undefined in the bytecode program.
+ // If all the symbols are defined, the program is complete, and there is