tools/llvm-ld/llvm-ld.cpp

   1 //===- llvm-ld.cpp - LLVM 'ld' compatible linker --------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This utility is intended to be compatible with GCC, and follows standard
  11 // system 'ld' conventions.  As such, the default output file is ./a.out.
  12 // Additionally, this program outputs a shell script that is used to invoke LLI
  13 // to execute the program.  In this manner, the generated executable (a.out for
  14 // example), is directly executable, whereas the bitcode file actually lives in
  15 // the a.out.bc file generated by this program.
  16 //
  17 // Note that if someone (or a script) deletes the executable program generated,
  18 // the .bc file will be left around.  Considering that this is a temporary hack,
  19 // I'm not too worried about this.
  20 //
  21 //===----------------------------------------------------------------------===//
  22
  23 #include "llvm/LinkAllVMCore.h"
  24 #include "llvm/Linker.h"
  25 #include "llvm/LLVMContext.h"
  26 #include "llvm/Support/Program.h"
  27 #include "llvm/Module.h"
  28 #include "llvm/PassManager.h"
  29 #include "llvm/Bitcode/ReaderWriter.h"
  30 #include "llvm/Target/TargetData.h"
  31 #include "llvm/Target/TargetMachine.h"
  32 #include "llvm/Support/CommandLine.h"
  33 #include "llvm/Support/FileUtilities.h"
  34 #include "llvm/Support/ManagedStatic.h"
  35 #include "llvm/Support/MemoryBuffer.h"
  36 #include "llvm/Support/PrettyStackTrace.h"
  37 #include "llvm/Support/SystemUtils.h"
  38 #include "llvm/Support/ToolOutputFile.h"
  39 #include "llvm/Support/Signals.h"
  40 #include "llvm/Config/config.h"
  41 #include <memory>
  42 #include <cstring>
  43 using namespace llvm;
  44
  45 // Rightly this should go in a header file but it just seems such a waste.
  46 namespace llvm {
  47 extern void Optimize(Module*);
  48 }
  49
  50 // Input/Output Options
  51 static cl::list<std::string> InputFilenames(cl::Positional, cl::OneOrMore,
  52   cl::desc("<input bitcode files>"));
  53
  54 static cl::opt<std::string> OutputFilename("o", cl::init("a.out"),
  55   cl::desc("Override output filename"),
  56   cl::value_desc("filename"));
  57
  58 static cl::opt<std::string> BitcodeOutputFilename("b", cl::init(""),
  59   cl::desc("Override bitcode output filename"),
  60   cl::value_desc("filename"));
  61
  62 static cl::opt<bool> Verbose("v",
  63   cl::desc("Print information about actions taken"));
  64
  65 static cl::list<std::string> LibPaths("L", cl::Prefix,
  66   cl::desc("Specify a library search path"),
  67   cl::value_desc("directory"));
  68
  69 static cl::list<std::string> FrameworkPaths("F", cl::Prefix,
  70   cl::desc("Specify a framework search path"),
  71   cl::value_desc("directory"));
  72
  73 static cl::list<std::string> Libraries("l", cl::Prefix,
  74   cl::desc("Specify libraries to link to"),
  75   cl::value_desc("library prefix"));
  76
  77 static cl::list<std::string> Frameworks("framework",
  78   cl::desc("Specify frameworks to link to"),
  79   cl::value_desc("framework"));
  80
  81 // Options to control the linking, optimization, and code gen processes
  82 static cl::opt<bool> LinkAsLibrary("link-as-library",
  83   cl::desc("Link the .bc files together as a library, not an executable"));
  84
  85 static cl::alias Relink("r", cl::aliasopt(LinkAsLibrary),
  86   cl::desc("Alias for -link-as-library"));
  87
  88 static cl::opt<bool> Native("native",
  89   cl::desc("Generate a native binary instead of a shell script"));
  90
  91 static cl::opt<bool>NativeCBE("native-cbe",
  92   cl::desc("Generate a native binary with the C backend and GCC"));
  93
  94 static cl::list<std::string> PostLinkOpts("post-link-opts",
  95   cl::value_desc("path"),
  96   cl::desc("Run one or more optimization programs after linking"));
  97
  98 static cl::list<std::string> XLinker("Xlinker", cl::value_desc("option"),
  99   cl::desc("Pass options to the system linker"));
 100
 101 // Compatibility options that llvm-ld ignores but are supported for
 102 // compatibility with LD
 103 static cl::opt<std::string> CO3("soname", cl::Hidden,
 104   cl::desc("Compatibility option: ignored"));
 105
 106 static cl::opt<std::string> CO4("version-script", cl::Hidden,
 107   cl::desc("Compatibility option: ignored"));
 108
 109 static cl::opt<bool> CO5("eh-frame-hdr", cl::Hidden,
 110   cl::desc("Compatibility option: ignored"));
 111
 112 static  cl::opt<std::string> CO6("h", cl::Hidden,
 113   cl::desc("Compatibility option: ignored"));
 114
 115 static cl::opt<bool> CO7("start-group", cl::Hidden,
 116   cl::desc("Compatibility option: ignored"));
 117
 118 static cl::opt<bool> CO8("end-group", cl::Hidden,
 119   cl::desc("Compatibility option: ignored"));
 120
 121 static cl::opt<std::string> CO9("m", cl::Hidden,
 122   cl::desc("Compatibility option: ignored"));
 123
 124 /// This is just for convenience so it doesn't have to be passed around
 125 /// everywhere.
 126 static std::string progname;
 127
 128 /// FileRemover objects to clean up output files in the event of an error.
 129 static FileRemover OutputRemover;
 130 static FileRemover BitcodeOutputRemover;
 131
 132 /// PrintAndExit - Prints a message to standard error and exits with error code
 133 ///
 134 /// Inputs:
 135 ///  Message  - The message to print to standard error.
 136 ///
 137 static void PrintAndExit(const std::string &Message, Module *M, int errcode = 1) {
 138   errs() << progname << ": " << Message << "\n";
 139   delete M;
 140   llvm_shutdown();
 141   exit(errcode);
 142 }
 143
 144 static void PrintCommand(const std::vector<const char*> &args) {
 145   std::vector<const char*>::const_iterator I = args.begin(), E = args.end();
 146   for (; I != E; ++I)
 147     if (*I)
 148       errs() << "'" << *I << "'" << " ";
 149   errs() << "\n";
 150 }
 151
 152 /// CopyEnv - This function takes an array of environment variables and makes a
 153 /// copy of it.  This copy can then be manipulated any way the caller likes
 154 /// without affecting the process's real environment.
 155 ///
 156 /// Inputs:
 157 ///  envp - An array of C strings containing an environment.
 158 ///
 159 /// Return value:
 160 ///  NULL - An error occurred.
 161 ///
 162 ///  Otherwise, a pointer to a new array of C strings is returned.  Every string
 163 ///  in the array is a duplicate of the one in the original array (i.e. we do
 164 ///  not copy the char *'s from one array to another).
 165 ///
 166 static char ** CopyEnv(char ** const envp) {
 167   // Count the number of entries in the old list;
 168   unsigned entries;   // The number of entries in the old environment list
 169   for (entries = 0; envp[entries] != NULL; entries++)
 170     /*empty*/;
 171
 172   // Add one more entry for the NULL pointer that ends the list.
 173   ++entries;
 174
 175   // If there are no entries at all, just return NULL.
 176   if (entries == 0)
 177     return NULL;
 178
 179   // Allocate a new environment list.
 180   char **newenv = new char* [entries];
 181   if (newenv == NULL)
 182     return NULL;
 183
 184   // Make a copy of the list.  Don't forget the NULL that ends the list.
 185   entries = 0;
 186   while (envp[entries] != NULL) {
 187     size_t len = strlen(envp[entries]) + 1;
 188     newenv[entries] = new char[len];
 189     memcpy(newenv[entries], envp[entries], len);
 190     ++entries;
 191   }
 192   newenv[entries] = NULL;
 193
 194   return newenv;
 195 }
 196
 197
 198 /// RemoveEnv - Remove the specified environment variable from the environment
 199 /// array.
 200 ///
 201 /// Inputs:
 202 ///  name - The name of the variable to remove.  It cannot be NULL.
 203 ///  envp - The array of environment variables.  It cannot be NULL.
 204 ///
 205 /// Notes:
 206 ///  This is mainly done because functions to remove items from the environment
 207 ///  are not available across all platforms.  In particular, Solaris does not
 208 ///  seem to have an unsetenv() function or a setenv() function (or they are
 209 ///  undocumented if they do exist).
 210 ///
 211 static void RemoveEnv(const char * name, char ** const envp) {
 212   for (unsigned index=0; envp[index] != NULL; index++) {
 213     // Find the first equals sign in the array and make it an EOS character.
 214     char *p = strchr (envp[index], '=');
 215     if (p == NULL)
 216       continue;
 217     else
 218       *p = '\0';
 219
 220     // Compare the two strings.  If they are equal, zap this string.
 221     // Otherwise, restore it.
 222     if (!strcmp(name, envp[index]))
 223       *envp[index] = '\0';
 224     else
 225       *p = '=';
 226   }
 227
 228   return;
 229 }
 230
 231 /// GenerateBitcode - generates a bitcode file from the module provided
 232 void GenerateBitcode(Module* M, const std::string& FileName) {
 233
 234   if (Verbose)
 235     errs() << "Generating Bitcode To " << FileName << '\n';
 236
 237   // Create the output file.
 238   std::string ErrorInfo;
 239   tool_output_file Out(FileName.c_str(), ErrorInfo,
 240                        raw_fd_ostream::F_Binary);
 241   if (!ErrorInfo.empty()) {
 242     PrintAndExit(ErrorInfo, M);
 243     return;
 244   }
 245
 246   // Write it out
 247   WriteBitcodeToFile(M, Out.os());
 248   Out.keep();
 249 }
 250
 251 /// GenerateAssembly - generates a native assembly language source file from the
 252 /// specified bitcode file.
 253 ///
 254 /// Inputs:
 255 ///  InputFilename  - The name of the input bitcode file.
 256 ///  OutputFilename - The name of the file to generate.
 257 ///  llc            - The pathname to use for LLC.
 258 ///  envp           - The environment to use when running LLC.
 259 ///
 260 /// Return non-zero value on error.
 261 ///
 262 static int GenerateAssembly(const std::string &OutputFilename,
 263                             const std::string &InputFilename,
 264                             const sys::Path &llc,
 265                             std::string &ErrMsg ) {
 266   // Run LLC to convert the bitcode file into assembly code.
 267   std::vector<const char*> args;
 268   args.push_back(llc.c_str());
 269   // We will use GCC to assemble the program so set the assembly syntax to AT&T,
 270   // regardless of what the target in the bitcode file is.
 271   args.push_back("-x86-asm-syntax=att");
 272   args.push_back("-o");
 273   args.push_back(OutputFilename.c_str());
 274   args.push_back(InputFilename.c_str());
 275   args.push_back(0);
 276
 277   if (Verbose) {
 278     errs() << "Generating Assembly With: \n";
 279     PrintCommand(args);
 280   }
 281
 282   return sys::Program::ExecuteAndWait(llc, &args[0], 0, 0, 0, 0, &ErrMsg);
 283 }
 284
 285 /// GenerateCFile - generates a C source file from the specified bitcode file.
 286 static int GenerateCFile(const std::string &OutputFile,
 287                          const std::string &InputFile,
 288                          const sys::Path &llc,
 289                          std::string& ErrMsg) {
 290   // Run LLC to convert the bitcode file into C.
 291   std::vector<const char*> args;
 292   args.push_back(llc.c_str());
 293   args.push_back("-march=c");
 294   args.push_back("-o");
 295   args.push_back(OutputFile.c_str());
 296   args.push_back(InputFile.c_str());
 297   args.push_back(0);
 298
 299   if (Verbose) {
 300     errs() << "Generating C Source With: \n";
 301     PrintCommand(args);
 302   }
 303
 304   return sys::Program::ExecuteAndWait(llc, &args[0], 0, 0, 0, 0, &ErrMsg);
 305 }
 306
 307 /// GenerateNative - generates a native object file from the
 308 /// specified bitcode file.
 309 ///
 310 /// Inputs:
 311 ///  InputFilename   - The name of the input bitcode file.
 312 ///  OutputFilename  - The name of the file to generate.
 313 ///  NativeLinkItems - The native libraries, files, code with which to link
 314 ///  LibPaths        - The list of directories in which to find libraries.
 315 ///  FrameworksPaths - The list of directories in which to find frameworks.
 316 ///  Frameworks      - The list of frameworks (dynamic libraries)
 317 ///  gcc             - The pathname to use for GGC.
 318 ///  envp            - A copy of the process's current environment.
 319 ///
 320 /// Outputs:
 321 ///  None.
 322 ///
 323 /// Returns non-zero value on error.
 324 ///
 325 static int GenerateNative(const std::string &OutputFilename,
 326                           const std::string &InputFilename,
 327                           const Linker::ItemList &LinkItems,
 328                           const sys::Path &gcc, char ** const envp,
 329                           std::string& ErrMsg) {
 330   // Remove these environment variables from the environment of the
 331   // programs that we will execute.  It appears that GCC sets these
 332   // environment variables so that the programs it uses can configure
 333   // themselves identically.
 334   //
 335   // However, when we invoke GCC below, we want it to use its normal
 336   // configuration.  Hence, we must sanitize its environment.
 337   char ** clean_env = CopyEnv(envp);
 338   if (clean_env == NULL)
 339     return 1;
 340   RemoveEnv("LIBRARY_PATH", clean_env);
 341   RemoveEnv("COLLECT_GCC_OPTIONS", clean_env);
 342   RemoveEnv("GCC_EXEC_PREFIX", clean_env);
 343   RemoveEnv("COMPILER_PATH", clean_env);
 344   RemoveEnv("COLLECT_GCC", clean_env);
 345
 346
 347   // Run GCC to assemble and link the program into native code.
 348   //
 349   // Note:
 350   //  We can't just assemble and link the file with the system assembler
 351   //  and linker because we don't know where to put the _start symbol.
 352   //  GCC mysteriously knows how to do it.
 353   std::vector<std::string> args;
 354   args.push_back(gcc.c_str());
 355   args.push_back("-fno-strict-aliasing");
 356   args.push_back("-O3");
 357   args.push_back("-o");
 358   args.push_back(OutputFilename);
 359   args.push_back(InputFilename);
 360
 361   // Add in the library and framework paths
 362   for (unsigned index = 0; index < LibPaths.size(); index++) {
 363     args.push_back("-L" + LibPaths[index]);
 364   }
 365   for (unsigned index = 0; index < FrameworkPaths.size(); index++) {
 366     args.push_back("-F" + FrameworkPaths[index]);
 367   }
 368
 369   // Add the requested options
 370   for (unsigned index = 0; index < XLinker.size(); index++)
 371     args.push_back(XLinker[index]);
 372
 373   // Add in the libraries to link.
 374   for (unsigned index = 0; index < LinkItems.size(); index++)
 375     if (LinkItems[index].first != "crtend") {
 376       if (LinkItems[index].second)
 377         args.push_back("-l" + LinkItems[index].first);
 378       else
 379         args.push_back(LinkItems[index].first);
 380     }
 381
 382   // Add in frameworks to link.
 383   for (unsigned index = 0; index < Frameworks.size(); index++) {
 384     args.push_back("-framework");
 385     args.push_back(Frameworks[index]);
 386   }
 387
 388   // Now that "args" owns all the std::strings for the arguments, call the c_str
 389   // method to get the underlying string array.  We do this game so that the
 390   // std::string array is guaranteed to outlive the const char* array.
 391   std::vector<const char *> Args;
 392   for (unsigned i = 0, e = args.size(); i != e; ++i)
 393     Args.push_back(args[i].c_str());
 394   Args.push_back(0);
 395
 396   if (Verbose) {
 397     errs() << "Generating Native Executable With:\n";
 398     PrintCommand(Args);
 399   }
 400
 401   // Run the compiler to assembly and link together the program.
 402   int R = sys::Program::ExecuteAndWait(
 403     gcc, &Args[0], const_cast<const char **>(clean_env), 0, 0, 0, &ErrMsg);
 404   delete [] clean_env;
 405   return R;
 406 }
 407
 408 /// EmitShellScript - Output the wrapper file that invokes the JIT on the LLVM
 409 /// bitcode file for the program.
 410 static void EmitShellScript(char **argv, Module *M) {
 411   if (Verbose)
 412     errs() << "Emitting Shell Script\n";
 413 #if defined(_WIN32)
 414   // Windows doesn't support #!/bin/sh style shell scripts in .exe files.  To
 415   // support windows systems, we copy the llvm-stub.exe executable from the
 416   // build tree to the destination file.
 417   std::string ErrMsg;
 418   sys::Path llvmstub = PrependMainExecutablePath("llvm-stub", argv[0],
 419                                                  (void *)(intptr_t)&Optimize);
 420   if (llvmstub.isEmpty())
 421     PrintAndExit("Could not find llvm-stub.exe executable!", M);
 422
 423   if (0 != sys::CopyFile(sys::Path(OutputFilename), llvmstub, &ErrMsg))
 424     PrintAndExit(ErrMsg, M);
 425
 426   return;
 427 #endif
 428
 429   // Output the script to start the program...
 430   std::string ErrorInfo;
 431   tool_output_file Out2(OutputFilename.c_str(), ErrorInfo);
 432   if (!ErrorInfo.empty())
 433     PrintAndExit(ErrorInfo, M);
 434
 435   Out2.os() << "#!/bin/sh\n";
 436   // Allow user to setenv LLVMINTERP if lli is not in their PATH.
 437   Out2.os() << "lli=${LLVMINTERP-lli}\n";
 438   Out2.os() << "exec $lli \\\n";
 439   // gcc accepts -l<lib> and implicitly searches /lib and /usr/lib.
 440   LibPaths.push_back("/lib");
 441   LibPaths.push_back("/usr/lib");
 442   LibPaths.push_back("/usr/X11R6/lib");
 443   // We don't need to link in libc! In fact, /usr/lib/libc.so may not be a
 444   // shared object at all! See RH 8: plain text.
 445   std::vector<std::string>::iterator libc =
 446     std::find(Libraries.begin(), Libraries.end(), "c");
 447   if (libc != Libraries.end()) Libraries.erase(libc);
 448   // List all the shared object (native) libraries this executable will need
 449   // on the command line, so that we don't have to do this manually!
 450   for (std::vector<std::string>::iterator i = Libraries.begin(),
 451          e = Libraries.end(); i != e; ++i) {
 452     // try explicit -L arguments first:
 453     sys::Path FullLibraryPath;
 454     for (cl::list<std::string>::const_iterator P = LibPaths.begin(),
 455            E = LibPaths.end(); P != E; ++P) {
 456       FullLibraryPath = *P;
 457       FullLibraryPath.appendComponent("lib" + *i);
 458       FullLibraryPath.appendSuffix(sys::Path::GetDLLSuffix());
 459       if (!FullLibraryPath.isEmpty()) {
 460         if (!FullLibraryPath.isDynamicLibrary()) {
 461           // Not a native shared library; mark as invalid
 462           FullLibraryPath = sys::Path();
 463         } else break;
 464       }
 465     }
 466     if (FullLibraryPath.isEmpty())
 467       FullLibraryPath = sys::Path::FindLibrary(*i);
 468     if (!FullLibraryPath.isEmpty())
 469       Out2.os() << "    -load=" << FullLibraryPath.str() << " \\\n";
 470   }
 471   Out2.os() << "    "  << BitcodeOutputFilename << " ${1+\"$@\"}\n";
 472   Out2.keep();
 473 }
 474
 475 // BuildLinkItems -- This function generates a LinkItemList for the LinkItems
 476 // linker function by combining the Files and Libraries in the order they were
 477 // declared on the command line.
 478 static void BuildLinkItems(
 479   Linker::ItemList& Items,
 480   const cl::list<std::string>& Files,
 481   const cl::list<std::string>& Libraries) {
 482
 483   // Build the list of linkage items for LinkItems.
 484
 485   cl::list<std::string>::const_iterator fileIt = Files.begin();
 486   cl::list<std::string>::const_iterator libIt  = Libraries.begin();
 487
 488   int libPos = -1, filePos = -1;
 489   while ( libIt != Libraries.end() || fileIt != Files.end() ) {
 490     if (libIt != Libraries.end())
 491       libPos = Libraries.getPosition(libIt - Libraries.begin());
 492     else
 493       libPos = -1;
 494     if (fileIt != Files.end())
 495       filePos = Files.getPosition(fileIt - Files.begin());
 496     else
 497       filePos = -1;
 498
 499     if (filePos != -1 && (libPos == -1 || filePos < libPos)) {
 500       // Add a source file
 501       Items.push_back(std::make_pair(*fileIt++, false));
 502     } else if (libPos != -1 && (filePos == -1 || libPos < filePos)) {
 503       // Add a library
 504       Items.push_back(std::make_pair(*libIt++, true));
 505     }
 506   }
 507 }
 508
 509 int main(int argc, char **argv, char **envp) {
 510   // Print a stack trace if we signal out.
 511   sys::PrintStackTraceOnErrorSignal();
 512   PrettyStackTraceProgram X(argc, argv);
 513
 514   LLVMContext &Context = getGlobalContext();
 515   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 516
 517   // Initialize passes
 518   PassRegistry &Registry = *PassRegistry::getPassRegistry();
 519   initializeCore(Registry);
 520   initializeScalarOpts(Registry);
 521   initializeIPO(Registry);
 522   initializeAnalysis(Registry);
 523   initializeIPA(Registry);
 524   initializeTransformUtils(Registry);
 525   initializeInstCombine(Registry);
 526   initializeTarget(Registry);
 527
 528   // Initial global variable above for convenience printing of program name.
 529   progname = sys::path::stem(argv[0]);
 530
 531   // Parse the command line options
 532   cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
 533
 534 #if defined(_WIN32) || defined(__CYGWIN__)
 535   if (!LinkAsLibrary) {
 536     // Default to "a.exe" instead of "a.out".
 537     if (OutputFilename.getNumOccurrences() == 0)
 538       OutputFilename = "a.exe";
 539
 540     // If there is no suffix add an "exe" one.
 541     if (sys::path::extension(OutputFilename).empty())
 542       OutputFilename.append(".exe");
 543   }
 544 #endif
 545
 546   // Generate the bitcode for the optimized module.
 547   // If -b wasn't specified, use the name specified
 548   // with -o to construct BitcodeOutputFilename.
 549   if (BitcodeOutputFilename.empty()) {
 550     BitcodeOutputFilename = OutputFilename;
 551     if (!LinkAsLibrary) BitcodeOutputFilename += ".bc";
 552   }
 553
 554   // Arrange for the bitcode output file to be deleted on any errors.
 555   BitcodeOutputRemover.setFile(BitcodeOutputFilename);
 556   sys::RemoveFileOnSignal(sys::Path(BitcodeOutputFilename));
 557
 558   // Arrange for the output file to be deleted on any errors.
 559   if (!LinkAsLibrary) {
 560     OutputRemover.setFile(OutputFilename);
 561     sys::RemoveFileOnSignal(sys::Path(OutputFilename));
 562   }
 563
 564   // Construct a Linker (now that Verbose is set)
 565   Linker TheLinker(progname, OutputFilename, Context, Verbose);
 566
 567   // Keep track of the native link items (versus the bitcode items)
 568   Linker::ItemList NativeLinkItems;
 569
 570   // Add library paths to the linker
 571   TheLinker.addPaths(LibPaths);
 572   TheLinker.addSystemPaths();
 573
 574   // Remove any consecutive duplicates of the same library...
 575   Libraries.erase(std::unique(Libraries.begin(), Libraries.end()),
 576                   Libraries.end());
 577
 578   if (LinkAsLibrary) {
 579     std::vector<sys::Path> Files;
 580     for (unsigned i = 0; i < InputFilenames.size(); ++i )
 581       Files.push_back(sys::Path(InputFilenames[i]));
 582     if (TheLinker.LinkInFiles(Files))
 583       return 1; // Error already printed
 584
 585     // The libraries aren't linked in but are noted as "dependent" in the
 586     // module.
 587     for (cl::list<std::string>::const_iterator I = Libraries.begin(),
 588          E = Libraries.end(); I != E ; ++I) {
 589       TheLinker.getModule()->addLibrary(*I);
 590     }
 591   } else {
 592     // Build a list of the items from our command line
 593     Linker::ItemList Items;
 594     BuildLinkItems(Items, InputFilenames, Libraries);
 595
 596     // Link all the items together
 597     if (TheLinker.LinkInItems(Items, NativeLinkItems) )
 598       return 1; // Error already printed
 599   }
 600
 601   std::auto_ptr<Module> Composite(TheLinker.releaseModule());
 602
 603   // Optimize the module
 604   Optimize(Composite.get());
 605
 606   // Generate the bitcode output.
 607   GenerateBitcode(Composite.get(), BitcodeOutputFilename);
 608
 609   // If we are not linking a library, generate either a native executable
 610   // or a JIT shell script, depending upon what the user wants.
 611   if (!LinkAsLibrary) {
 612     // If the user wants to run a post-link optimization, run it now.
 613     if (!PostLinkOpts.empty()) {
 614       std::vector<std::string> opts = PostLinkOpts;
 615       for (std::vector<std::string>::iterator I = opts.begin(),
 616            E = opts.end(); I != E; ++I) {
 617         sys::Path prog(*I);
 618         if (!prog.canExecute()) {
 619           prog = sys::Program::FindProgramByName(*I);
 620           if (prog.isEmpty())
 621             PrintAndExit(std::string("Optimization program '") + *I +
 622                          "' is not found or not executable.", Composite.get());
 623         }
 624         // Get the program arguments
 625         sys::Path tmp_output("opt_result");
 626         std::string ErrMsg;
 627         if (tmp_output.createTemporaryFileOnDisk(true, &ErrMsg))
 628           PrintAndExit(ErrMsg, Composite.get());
 629
 630         const char* args[4];
 631         args[0] = I->c_str();
 632         args[1] = BitcodeOutputFilename.c_str();
 633         args[2] = tmp_output.c_str();
 634         args[3] = 0;
 635         if (0 == sys::Program::ExecuteAndWait(prog, args, 0,0,0,0, &ErrMsg)) {
 636           if (tmp_output.isBitcodeFile()) {
 637             sys::Path target(BitcodeOutputFilename);
 638             target.eraseFromDisk();
 639             if (tmp_output.renamePathOnDisk(target, &ErrMsg))
 640               PrintAndExit(ErrMsg, Composite.get(), 2);
 641           } else
 642             PrintAndExit("Post-link optimization output is not bitcode",
 643                          Composite.get());
 644         } else {
 645           PrintAndExit(ErrMsg, Composite.get());
 646         }
 647       }
 648     }
 649
 650     // If the user wants to generate a native executable, compile it from the
 651     // bitcode file.
 652     //
 653     // Otherwise, create a script that will run the bitcode through the JIT.
 654     if (Native) {
 655       // Name of the Assembly Language output file
 656       sys::Path AssemblyFile ( OutputFilename);
 657       AssemblyFile.appendSuffix("s");
 658
 659       // Mark the output files for removal.
 660       FileRemover AssemblyFileRemover(AssemblyFile.str());
 661       sys::RemoveFileOnSignal(AssemblyFile);
 662
 663       // Determine the locations of the llc and gcc programs.
 664       sys::Path llc = PrependMainExecutablePath("llc", argv[0],
 665                                                 (void *)(intptr_t)&Optimize);
 666       if (llc.isEmpty())
 667         PrintAndExit("Failed to find llc", Composite.get());
 668
 669       sys::Path gcc = sys::Program::FindProgramByName("gcc");
 670       if (gcc.isEmpty())
 671         PrintAndExit("Failed to find gcc", Composite.get());
 672
 673       // Generate an assembly language file for the bitcode.
 674       std::string ErrMsg;
 675       if (0 != GenerateAssembly(AssemblyFile.str(), BitcodeOutputFilename,
 676           llc, ErrMsg))
 677         PrintAndExit(ErrMsg, Composite.get());
 678
 679       if (0 != GenerateNative(OutputFilename, AssemblyFile.str(),
 680                               NativeLinkItems, gcc, envp, ErrMsg))
 681         PrintAndExit(ErrMsg, Composite.get());
 682     } else if (NativeCBE) {
 683       sys::Path CFile (OutputFilename);
 684       CFile.appendSuffix("cbe.c");
 685
 686       // Mark the output files for removal.
 687       FileRemover CFileRemover(CFile.str());
 688       sys::RemoveFileOnSignal(CFile);
 689
 690       // Determine the locations of the llc and gcc programs.
 691       sys::Path llc = PrependMainExecutablePath("llc", argv[0],
 692                                                 (void *)(intptr_t)&Optimize);
 693       if (llc.isEmpty())
 694         PrintAndExit("Failed to find llc", Composite.get());
 695
 696       sys::Path gcc = sys::Program::FindProgramByName("gcc");
 697       if (gcc.isEmpty())
 698         PrintAndExit("Failed to find gcc", Composite.get());
 699
 700       // Generate an assembly language file for the bitcode.
 701       std::string ErrMsg;
 702       if (GenerateCFile(CFile.str(), BitcodeOutputFilename, llc, ErrMsg))
 703         PrintAndExit(ErrMsg, Composite.get());
 704
 705       if (GenerateNative(OutputFilename, CFile.str(),
 706                          NativeLinkItems, gcc, envp, ErrMsg))
 707         PrintAndExit(ErrMsg, Composite.get());
 708     } else {
 709       EmitShellScript(argv, Composite.get());
 710     }
 711
 712     // Make the script executable...
 713     std::string ErrMsg;
 714     if (sys::Path(OutputFilename).makeExecutableOnDisk(&ErrMsg))
 715       PrintAndExit(ErrMsg, Composite.get());
 716
 717     // Make the bitcode file readable and directly executable in LLEE as well
 718     if (sys::Path(BitcodeOutputFilename).makeExecutableOnDisk(&ErrMsg))
 719       PrintAndExit(ErrMsg, Composite.get());
 720
 721     if (sys::Path(BitcodeOutputFilename).makeReadableOnDisk(&ErrMsg))
 722       PrintAndExit(ErrMsg, Composite.get());
 723   }
 724
 725   // Operations which may fail are now complete.
 726   BitcodeOutputRemover.releaseFile();
 727   if (!LinkAsLibrary)
 728     OutputRemover.releaseFile();
 729
 730   // Graceful exit
 731   return 0;
 732 }