1 //===- gccld.cpp - LLVM 'ld' compatible linker ----------------------------===//
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 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 bytecode file actually lives in
15 // the a.out.bc file generated by this program. Also, Force is on by default.
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.
21 //===----------------------------------------------------------------------===//
24 #include "llvm/Module.h"
25 #include "llvm/PassManager.h"
26 #include "llvm/Bytecode/Reader.h"
27 #include "llvm/Bytecode/WriteBytecodePass.h"
28 #include "llvm/Target/TargetData.h"
29 #include "llvm/Transforms/IPO.h"
30 #include "llvm/Transforms/Scalar.h"
31 #include "llvm/Transforms/Utils/Linker.h"
32 #include "Support/CommandLine.h"
33 #include "Support/FileUtilities.h"
34 #include "Support/Signals.h"
35 #include "Support/SystemUtils.h"
43 InputFilenames(cl::Positional, cl::desc("<input bytecode files>"),
47 OutputFilename("o", cl::desc("Override output filename"), cl::init("a.out"),
48 cl::value_desc("filename"));
51 Verbose("v", cl::desc("Print information about actions taken"));
54 LibPaths("L", cl::desc("Specify a library search path"), cl::Prefix,
55 cl::value_desc("directory"));
58 Libraries("l", cl::desc("Specify libraries to link to"), cl::Prefix,
59 cl::value_desc("library prefix"));
62 Strip("s", cl::desc("Strip symbol info from executable"));
65 NoInternalize("disable-internalize",
66 cl::desc("Do not mark all symbols as internal"));
68 ExportDynamic("export-dynamic", cl::desc("Alias for -disable-internalize"),
69 cl::aliasopt(NoInternalize));
72 LinkAsLibrary("link-as-library", cl::desc("Link the .bc files together as a"
73 " library, not an executable"));
75 Relink("r", cl::desc("Alias for -link-as-library"),
76 cl::aliasopt(LinkAsLibrary));
80 cl::desc("Generate a native binary instead of a shell script"));
82 NativeCBE("native-cbe",
83 cl::desc("Generate a native binary with the C backend and GCC"));
85 // Compatibility options that are ignored but supported by LD
87 CO3("soname", cl::Hidden, cl::desc("Compatibility option: ignored"));
89 CO4("version-script", cl::Hidden, cl::desc("Compatibility option: ignored"));
91 CO5("eh-frame-hdr", cl::Hidden, cl::desc("Compatibility option: ignored"));
93 CO6("h", cl::Hidden, cl::desc("Compatibility option: ignored"));
98 /// PrintAndReturn - Prints a message to standard error and returns a value
99 /// usable for an exit status.
102 /// progname - The name of the program (i.e. argv[0]).
103 /// Message - The message to print to standard error.
104 /// Extra - Extra information to print between the program name and thei
105 /// message. It is optional.
108 /// Returns a value that can be used as the exit status (i.e. for exit()).
111 PrintAndReturn(const char *progname,
112 const std::string &Message,
113 const std::string &Extra)
115 std::cerr << progname << Extra << ": " << Message << "\n";
119 /// CopyEnv - This function takes an array of environment variables and makes a
120 /// copy of it. This copy can then be manipulated any way the caller likes
121 /// without affecting the process's real environment.
124 /// envp - An array of C strings containing an environment.
127 /// NULL - An error occurred.
129 /// Otherwise, a pointer to a new array of C strings is returned. Every string
130 /// in the array is a duplicate of the one in the original array (i.e. we do
131 /// not copy the char *'s from one array to another).
133 char ** CopyEnv(char ** const envp) {
134 // Count the number of entries in the old list;
135 unsigned entries; // The number of entries in the old environment list
136 for (entries = 0; envp[entries] != NULL; entries++)
139 // Add one more entry for the NULL pointer that ends the list.
142 // If there are no entries at all, just return NULL.
146 // Allocate a new environment list.
147 char **newenv = new char* [entries];
148 if ((newenv = new char* [entries]) == NULL)
151 // Make a copy of the list. Don't forget the NULL that ends the list.
153 while (envp[entries] != NULL) {
154 newenv[entries] = new char[strlen (envp[entries]) + 1];
155 strcpy (newenv[entries], envp[entries]);
158 newenv[entries] = NULL;
164 /// RemoveEnv - Remove the specified environment variable from the environment
168 /// name - The name of the variable to remove. It cannot be NULL.
169 /// envp - The array of environment variables. It cannot be NULL.
172 /// This is mainly done because functions to remove items from the environment
173 /// are not available across all platforms. In particular, Solaris does not
174 /// seem to have an unsetenv() function or a setenv() function (or they are
175 /// undocumented if they do exist).
177 void RemoveEnv(const char * name, char ** const envp) {
178 for (unsigned index=0; envp[index] != NULL; index++) {
179 // Find the first equals sign in the array and make it an EOS character.
180 char *p = strchr (envp[index], '=');
186 // Compare the two strings. If they are equal, zap this string.
187 // Otherwise, restore it.
188 if (!strcmp(name, envp[index]))
197 } // End llvm namespace
199 int main(int argc, char **argv, char **envp) {
200 cl::ParseCommandLineOptions(argc, argv, " llvm linker for GCC\n");
201 PrintStackTraceOnErrorSignal();
203 std::string ModuleID("gccld-output");
204 std::auto_ptr<Module> Composite(new Module(ModuleID));
206 // We always look first in the current directory when searching for libraries.
207 LibPaths.insert(LibPaths.begin(), ".");
209 // If the user specified an extra search path in their environment, respect
211 if (char *SearchPath = getenv("LLVM_LIB_SEARCH_PATH"))
212 LibPaths.push_back(SearchPath);
214 // Remove any consecutive duplicates of the same library...
215 Libraries.erase(std::unique(Libraries.begin(), Libraries.end()),
218 // Link in all of the files
219 if (LinkFiles(argv[0], Composite.get(), InputFilenames, Verbose))
220 return 1; // Error already printed
223 LinkLibraries(argv[0], Composite.get(), Libraries, LibPaths,
226 // Link in all of the libraries next...
228 // Create the output file.
229 std::string RealBytecodeOutput = OutputFilename;
230 if (!LinkAsLibrary) RealBytecodeOutput += ".bc";
231 std::ofstream Out(RealBytecodeOutput.c_str());
233 return PrintAndReturn(argv[0], "error opening '" + RealBytecodeOutput +
236 // Ensure that the bytecode file gets removed from the disk if we get a
238 RemoveFileOnSignal(RealBytecodeOutput);
240 // Generate the bytecode file.
241 if (GenerateBytecode(Composite.get(), Strip, !NoInternalize, &Out)) {
243 return PrintAndReturn(argv[0], "error generating bytecode");
246 // Close the bytecode file.
249 // If we are not linking a library, generate either a native executable
250 // or a JIT shell script, depending upon what the user wants.
251 if (!LinkAsLibrary) {
252 // If the user wants to generate a native executable, compile it from the
255 // Otherwise, create a script that will run the bytecode through the JIT.
257 // Name of the Assembly Language output file
258 std::string AssemblyFile = OutputFilename + ".s";
260 // Mark the output files for removal if we get an interrupt.
261 RemoveFileOnSignal(AssemblyFile);
262 RemoveFileOnSignal(OutputFilename);
264 // Determine the locations of the llc and gcc programs.
265 std::string llc = FindExecutable("llc", argv[0]);
266 std::string gcc = FindExecutable("gcc", argv[0]);
268 return PrintAndReturn(argv[0], "Failed to find llc");
271 return PrintAndReturn(argv[0], "Failed to find gcc");
273 // Generate an assembly language file for the bytecode.
274 if (Verbose) std::cout << "Generating Assembly Code\n";
275 GenerateAssembly(AssemblyFile, RealBytecodeOutput, llc, envp);
276 if (Verbose) std::cout << "Generating Native Code\n";
277 GenerateNative(OutputFilename, AssemblyFile, Libraries, LibPaths,
280 // Remove the assembly language file.
281 removeFile (AssemblyFile);
282 } else if (NativeCBE) {
283 std::string CFile = OutputFilename + ".cbe.c";
285 // Mark the output files for removal if we get an interrupt.
286 RemoveFileOnSignal(CFile);
287 RemoveFileOnSignal(OutputFilename);
289 // Determine the locations of the llc and gcc programs.
290 std::string llc = FindExecutable("llc", argv[0]);
291 std::string gcc = FindExecutable("gcc", argv[0]);
293 return PrintAndReturn(argv[0], "Failed to find llc");
295 return PrintAndReturn(argv[0], "Failed to find gcc");
297 // Generate an assembly language file for the bytecode.
298 if (Verbose) std::cout << "Generating Assembly Code\n";
299 GenerateCFile(CFile, RealBytecodeOutput, llc, envp);
300 if (Verbose) std::cout << "Generating Native Code\n";
301 GenerateNative(OutputFilename, CFile, Libraries, LibPaths, gcc, envp);
303 // Remove the assembly language file.
307 // Output the script to start the program...
308 std::ofstream Out2(OutputFilename.c_str());
310 return PrintAndReturn(argv[0], "error opening '" + OutputFilename +
312 Out2 << "#!/bin/sh\n";
313 // Allow user to setenv LLVMINTERP if lli is not in their PATH.
314 Out2 << "lli=${LLVMINTERP-lli}\n";
315 Out2 << "exec $lli \\\n";
316 // gcc accepts -l<lib> and implicitly searches /lib and /usr/lib.
317 LibPaths.push_back("/lib");
318 LibPaths.push_back("/usr/lib");
319 LibPaths.push_back("/usr/X11R6/lib");
320 // We don't need to link in libc! In fact, /usr/lib/libc.so may not be a
321 // shared object at all! See RH 8: plain text.
322 std::vector<std::string>::iterator libc =
323 std::find(Libraries.begin(), Libraries.end(), "c");
324 if (libc != Libraries.end()) Libraries.erase(libc);
325 // List all the shared object (native) libraries this executable will need
326 // on the command line, so that we don't have to do this manually!
327 for (std::vector<std::string>::iterator i = Libraries.begin(),
328 e = Libraries.end(); i != e; ++i) {
329 std::string FullLibraryPath = FindLib(*i, LibPaths, true);
330 if (!FullLibraryPath.empty() && IsSharedObject(FullLibraryPath))
331 Out2 << " -load=" << FullLibraryPath << " \\\n";
333 Out2 << " $0.bc ${1+\"$@\"}\n";
337 // Make the script executable...
338 MakeFileExecutable(OutputFilename);
340 // Make the bytecode file readable and directly executable in LLEE as well
341 MakeFileExecutable(RealBytecodeOutput);
342 MakeFileReadable(RealBytecodeOutput);