1 //===- GenerateCode.cpp - Functions for generating executable files ------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains functions for generating executable files once linking
11 // has finished. This includes generating a shell script to run the JIT or
12 // a native executable derived from the bytecode.
14 //===----------------------------------------------------------------------===//
17 #include "llvm/System/Program.h"
18 #include "llvm/Module.h"
19 #include "llvm/PassManager.h"
20 #include "llvm/Analysis/LoadValueNumbering.h"
21 #include "llvm/Analysis/Passes.h"
22 #include "llvm/Analysis/Verifier.h"
23 #include "llvm/Bytecode/Archive.h"
24 #include "llvm/Bytecode/WriteBytecodePass.h"
25 #include "llvm/Target/TargetData.h"
26 #include "llvm/Transforms/IPO.h"
27 #include "llvm/Transforms/Scalar.h"
28 #include "llvm/Support/SystemUtils.h"
29 #include "llvm/Support/CommandLine.h"
30 #include "llvm/Support/Streams.h"
35 DisableInline("disable-inlining", cl::desc("Do not run the inliner pass"));
38 Verify("verify", cl::desc("Verify intermediate results of all passes"));
41 DisableOptimizations("disable-opt",
42 cl::desc("Do not run any optimization passes"));
45 NoCompress("disable-compression", cl::init(true),
46 cl::desc("Don't compress the generated bytecode"));
49 /// CopyEnv - This function takes an array of environment variables and makes a
50 /// copy of it. This copy can then be manipulated any way the caller likes
51 /// without affecting the process's real environment.
54 /// envp - An array of C strings containing an environment.
57 /// NULL - An error occurred.
59 /// Otherwise, a pointer to a new array of C strings is returned. Every string
60 /// in the array is a duplicate of the one in the original array (i.e. we do
61 /// not copy the char *'s from one array to another).
63 static char ** CopyEnv(char ** const envp) {
64 // Count the number of entries in the old list;
65 unsigned entries; // The number of entries in the old environment list
66 for (entries = 0; envp[entries] != NULL; entries++)
69 // Add one more entry for the NULL pointer that ends the list.
72 // If there are no entries at all, just return NULL.
76 // Allocate a new environment list.
77 char **newenv = new char* [entries];
78 if ((newenv = new char* [entries]) == NULL)
81 // Make a copy of the list. Don't forget the NULL that ends the list.
83 while (envp[entries] != NULL) {
84 newenv[entries] = new char[strlen (envp[entries]) + 1];
85 strcpy (newenv[entries], envp[entries]);
88 newenv[entries] = NULL;
94 /// RemoveEnv - Remove the specified environment variable from the environment
98 /// name - The name of the variable to remove. It cannot be NULL.
99 /// envp - The array of environment variables. It cannot be NULL.
102 /// This is mainly done because functions to remove items from the environment
103 /// are not available across all platforms. In particular, Solaris does not
104 /// seem to have an unsetenv() function or a setenv() function (or they are
105 /// undocumented if they do exist).
107 static void RemoveEnv(const char * name, char ** const envp) {
108 for (unsigned index=0; envp[index] != NULL; index++) {
109 // Find the first equals sign in the array and make it an EOS character.
110 char *p = strchr (envp[index], '=');
116 // Compare the two strings. If they are equal, zap this string.
117 // Otherwise, restore it.
118 if (!strcmp(name, envp[index]))
125 static void dumpArgs(const char **args) {
128 cerr << ' ' << *args++;
129 cerr << '\n' << std::flush;
132 static inline void addPass(PassManager &PM, Pass *P) {
133 // Add the pass to the pass manager...
136 // If we are verifying all of the intermediate steps, add the verifier...
137 if (Verify) PM.add(createVerifierPass());
140 static bool isBytecodeLibrary(const sys::Path &FullPath) {
141 // Check for a bytecode file
142 if (FullPath.isBytecodeFile()) return true;
143 // Check for a dynamic library file
144 if (FullPath.isDynamicLibrary()) return false;
145 // Check for a true bytecode archive file
146 if (FullPath.isArchive() ) {
147 std::string ErrorMessage;
148 Archive* ar = Archive::OpenAndLoadSymbols( FullPath, &ErrorMessage );
149 return ar->isBytecodeArchive();
154 static bool isBytecodeLPath(const std::string &LibPath) {
155 sys::Path LPath(LibPath);
157 // Make sure it exists and is a directory
158 sys::FileStatus Status;
159 if (LPath.getFileStatus(Status) || !Status.isDir)
162 // Grab the contents of the -L path
163 std::set<sys::Path> Files;
164 if (LPath.getDirectoryContents(Files, 0))
167 // Iterate over the contents one by one to determine
168 // if this -L path has any bytecode shared libraries
170 std::set<sys::Path>::iterator File = Files.begin();
171 std::string dllsuffix = sys::Path::GetDLLSuffix();
172 for (; File != Files.end(); ++File) {
175 if (File->getFileStatus(Status) || Status.isDir)
178 std::string path = File->toString();
180 // Check for an ending '.dll', '.so' or '.a' suffix as all
181 // other files are not of interest to us here
182 if (path.find(dllsuffix, path.size()-dllsuffix.size()) == std::string::npos
183 && path.find(".a", path.size()-2) == std::string::npos)
186 // Finally, check to see if the file is a true bytecode file
187 if (isBytecodeLibrary(*File))
193 /// GenerateBytecode - generates a bytecode file from the specified module.
196 /// M - The module for which bytecode should be generated.
197 /// StripLevel - 2 if we should strip all symbols, 1 if we should strip
199 /// Internalize - Flags whether all symbols should be marked internal.
200 /// Out - Pointer to file stream to which to write the output.
202 /// Returns non-zero value on error.
204 int llvm::GenerateBytecode(Module *M, int StripLevel, bool Internalize,
206 // In addition to just linking the input from GCC, we also want to spiff it up
207 // a little bit. Do this now.
210 if (Verify) Passes.add(createVerifierPass());
212 // Add an appropriate TargetData instance for this module...
213 addPass(Passes, new TargetData(M));
215 // Often if the programmer does not specify proper prototypes for the
216 // functions they are calling, they end up calling a vararg version of the
217 // function that does not get a body filled in (the real function has typed
218 // arguments). This pass merges the two functions.
219 addPass(Passes, createFunctionResolvingPass());
221 if (!DisableOptimizations) {
222 // Now that composite has been compiled, scan through the module, looking
223 // for a main function. If main is defined, mark all other functions
225 addPass(Passes, createInternalizePass(Internalize));
227 // Propagate constants at call sites into the functions they call. This
228 // opens opportunities for globalopt (and inlining) by substituting function
229 // pointers passed as arguments to direct uses of functions.
230 addPass(Passes, createIPSCCPPass());
232 // Now that we internalized some globals, see if we can hack on them!
233 addPass(Passes, createGlobalOptimizerPass());
235 // Linking modules together can lead to duplicated global constants, only
236 // keep one copy of each constant...
237 addPass(Passes, createConstantMergePass());
239 // Remove unused arguments from functions...
240 addPass(Passes, createDeadArgEliminationPass());
243 addPass(Passes, createFunctionInliningPass()); // Inline small functions
245 addPass(Passes, createPruneEHPass()); // Remove dead EH info
246 addPass(Passes, createGlobalOptimizerPass()); // Optimize globals again.
247 addPass(Passes, createGlobalDCEPass()); // Remove dead functions
249 // If we didn't decide to inline a function, check to see if we can
250 // transform it to pass arguments by value instead of by reference.
251 addPass(Passes, createArgumentPromotionPass());
253 // The IPO passes may leave cruft around. Clean up after them.
254 addPass(Passes, createInstructionCombiningPass());
256 addPass(Passes, createScalarReplAggregatesPass()); // Break up allocas
258 // Run a few AA driven optimizations here and now, to cleanup the code.
259 addPass(Passes, createGlobalsModRefPass()); // IP alias analysis
261 addPass(Passes, createLICMPass()); // Hoist loop invariants
262 addPass(Passes, createLoadValueNumberingPass()); // GVN for load instrs
263 addPass(Passes, createGCSEPass()); // Remove common subexprs
264 addPass(Passes, createDeadStoreEliminationPass()); // Nuke dead stores
266 // Cleanup and simplify the code after the scalar optimizations.
267 addPass(Passes, createInstructionCombiningPass());
269 // Delete basic blocks, which optimization passes may have killed...
270 addPass(Passes, createCFGSimplificationPass());
272 // Now that we have optimized the program, discard unreachable functions...
273 addPass(Passes, createGlobalDCEPass());
276 // If the -s or -S command line options were specified, strip the symbols out
277 // of the resulting program to make it smaller. -s and -S are GLD options
278 // that we are supporting.
280 addPass(Passes, createStripSymbolsPass(StripLevel == 1));
282 // Make sure everything is still good.
283 Passes.add(createVerifierPass());
285 // Add the pass that writes bytecode to the output file...
287 addPass(Passes, new WriteBytecodePass(&L, false, !NoCompress));
289 // Run our queue of passes all at once now, efficiently.
295 /// GenerateAssembly - generates a native assembly language source file from the
296 /// specified bytecode file.
299 /// InputFilename - The name of the output bytecode file.
300 /// OutputFilename - The name of the file to generate.
301 /// llc - The pathname to use for LLC.
303 /// Return non-zero value on error.
305 int llvm::GenerateAssembly(const std::string &OutputFilename,
306 const std::string &InputFilename,
307 const sys::Path &llc,
310 // Run LLC to convert the bytecode file into assembly code.
311 std::vector<const char*> args;
312 args.push_back(llc.c_str());
313 args.push_back("-f");
314 args.push_back("-o");
315 args.push_back(OutputFilename.c_str());
316 args.push_back(InputFilename.c_str());
318 if (Verbose) dumpArgs(&args[0]);
319 return sys::Program::ExecuteAndWait(llc, &args[0],0,0,0,&ErrMsg);
322 /// GenerateCFile - generates a C source file from the specified bytecode file.
323 int llvm::GenerateCFile(const std::string &OutputFile,
324 const std::string &InputFile,
325 const sys::Path &llc,
328 // Run LLC to convert the bytecode file into C.
329 std::vector<const char*> args;
330 args.push_back(llc.c_str());
331 args.push_back("-march=c");
332 args.push_back("-f");
333 args.push_back("-o");
334 args.push_back(OutputFile.c_str());
335 args.push_back(InputFile.c_str());
337 if (Verbose) dumpArgs(&args[0]);
338 return sys::Program::ExecuteAndWait(llc, &args[0],0,0,0,&ErrMsg);
341 /// GenerateNative - generates a native executable file from the specified
342 /// assembly source file.
345 /// InputFilename - The name of the output bytecode file.
346 /// OutputFilename - The name of the file to generate.
347 /// Libraries - The list of libraries with which to link.
348 /// gcc - The pathname to use for GGC.
349 /// envp - A copy of the process's current environment.
354 /// Returns non-zero value on error.
356 int llvm::GenerateNative(const std::string &OutputFilename,
357 const std::string &InputFilename,
358 const std::vector<std::string> &LibPaths,
359 const std::vector<std::string> &Libraries,
360 const sys::Path &gcc, char ** const envp,
362 bool ExportAllAsDynamic,
363 const std::vector<std::string> &RPaths,
364 const std::string &SOName,
367 // Remove these environment variables from the environment of the
368 // programs that we will execute. It appears that GCC sets these
369 // environment variables so that the programs it uses can configure
370 // themselves identically.
372 // However, when we invoke GCC below, we want it to use its normal
373 // configuration. Hence, we must sanitize its environment.
374 char ** clean_env = CopyEnv(envp);
375 if (clean_env == NULL)
377 RemoveEnv("LIBRARY_PATH", clean_env);
378 RemoveEnv("COLLECT_GCC_OPTIONS", clean_env);
379 RemoveEnv("GCC_EXEC_PREFIX", clean_env);
380 RemoveEnv("COMPILER_PATH", clean_env);
381 RemoveEnv("COLLECT_GCC", clean_env);
384 // Run GCC to assemble and link the program into native code.
387 // We can't just assemble and link the file with the system assembler
388 // and linker because we don't know where to put the _start symbol.
389 // GCC mysteriously knows how to do it.
390 std::vector<const char*> args;
391 args.push_back(gcc.c_str());
392 args.push_back("-fno-strict-aliasing");
393 args.push_back("-O3");
394 args.push_back("-o");
395 args.push_back(OutputFilename.c_str());
396 args.push_back(InputFilename.c_str());
398 // StringsToDelete - We don't want to call c_str() on temporary strings.
399 // If we need a temporary string, copy it here so that the memory is not
400 // reclaimed until after the exec call. All of these strings are allocated
402 std::vector<char*> StringsToDelete;
404 if (Shared) args.push_back("-shared");
405 if (ExportAllAsDynamic) args.push_back("-export-dynamic");
406 if (!RPaths.empty()) {
407 for (std::vector<std::string>::const_iterator I = RPaths.begin(),
408 E = RPaths.end(); I != E; I++) {
409 std::string rp = "-Wl,-rpath," + *I;
410 StringsToDelete.push_back(strdup(rp.c_str()));
411 args.push_back(StringsToDelete.back());
414 if (!SOName.empty()) {
415 std::string so = "-Wl,-soname," + SOName;
416 StringsToDelete.push_back(strdup(so.c_str()));
417 args.push_back(StringsToDelete.back());
420 // Add in the libpaths to find the libraries.
423 // When gccld is called from the llvm-gxx frontends, the -L paths for
424 // the LLVM cfrontend install paths are appended. We don't want the
425 // native linker to use these -L paths as they contain bytecode files.
426 // Further, we don't want any -L paths that contain bytecode shared
427 // libraries or true bytecode archive files. We omit them in all such
429 for (unsigned index = 0; index < LibPaths.size(); index++)
430 if (!isBytecodeLPath(LibPaths[index])) {
431 std::string Tmp = "-L"+LibPaths[index];
432 StringsToDelete.push_back(strdup(Tmp.c_str()));
433 args.push_back(StringsToDelete.back());
436 // Add in the libraries to link.
437 for (unsigned index = 0; index < Libraries.size(); index++)
438 // HACK: If this is libg, discard it. This gets added by the compiler
439 // driver when doing: 'llvm-gcc main.c -Wl,-native -o a.out -g'. Note that
440 // this should really be fixed by changing the llvm-gcc compiler driver.
441 if (Libraries[index] != "crtend" && Libraries[index] != "g") {
442 std::string Tmp = "-l"+Libraries[index];
443 StringsToDelete.push_back(strdup(Tmp.c_str()));
444 args.push_back(StringsToDelete.back());
446 args.push_back(0); // Null terminate.
448 // Run the compiler to assembly and link together the program.
449 if (Verbose) dumpArgs(&args[0]);
450 int Res = sys::Program::ExecuteAndWait(
451 gcc, &args[0],(const char**)clean_env,0,0,&ErrMsg);
455 while (!StringsToDelete.empty()) {
456 free(StringsToDelete.back());
457 StringsToDelete.pop_back();