1 //===- llvm-ld.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/Target/TargetMachine.h"
30 #include "llvm/Target/TargetMachineRegistry.h"
31 #include "llvm/Transforms/IPO.h"
32 #include "llvm/Transforms/Scalar.h"
33 #include "llvm/Support/Linker.h"
34 #include "llvm/Support/CommandLine.h"
35 #include "llvm/Support/FileUtilities.h"
36 #include "llvm/System/Signals.h"
37 #include "llvm/Support/SystemUtils.h"
42 enum OptimizationLevels {
47 OPT_AGGRESSIVE_LINK_TIME
52 InputFilenames(cl::Positional, cl::desc("<input bytecode files>"),
56 OutputFilename("o", cl::desc("Override output filename"), cl::init("a.out"),
57 cl::value_desc("filename"));
60 Verbose("v", cl::desc("Print information about actions taken"));
63 LibPaths("L", cl::desc("Specify a library search path"), cl::Prefix,
64 cl::value_desc("directory"));
67 Libraries("l", cl::desc("Specify libraries to link to"), cl::Prefix,
68 cl::value_desc("library prefix"));
71 Strip("s", cl::desc("Strip symbol info from executable"));
74 NoInternalize("disable-internalize",
75 cl::desc("Do not mark all symbols as internal"));
77 ExportDynamic("export-dynamic", cl::desc("Alias for -disable-internalize"),
78 cl::aliasopt(NoInternalize));
81 LinkAsLibrary("link-as-library", cl::desc("Link the .bc files together as a"
82 " library, not an executable"));
84 Relink("r", cl::desc("Alias for -link-as-library"),
85 cl::aliasopt(LinkAsLibrary));
87 cl::opt<const TargetMachineRegistry::Entry*, false, TargetNameParser>
88 MachineArch("march", cl::desc("Architecture to generate assembly for:"));
92 cl::desc("Generate a native binary instead of a shell script"));
94 NativeCBE("native-cbe",
95 cl::desc("Generate a native binary with the C backend and GCC"));
97 // Compatibility options that are ignored but supported by LD
99 CO3("soname", cl::Hidden, cl::desc("Compatibility option: ignored"));
101 CO4("version-script", cl::Hidden, cl::desc("Compatibility option: ignored"));
103 CO5("eh-frame-hdr", cl::Hidden, cl::desc("Compatibility option: ignored"));
105 CO6("h", cl::Hidden, cl::desc("Compatibility option: ignored"));
107 cl::opt<OptimizationLevels> OptLevel(
108 cl::desc("Choose level of optimization to apply:"),
109 cl::init(OPT_FAST_COMPILE), cl::values(
110 clEnumValN(OPT_FAST_COMPILE,"O0",
111 "An alias for the -O1 option."),
112 clEnumValN(OPT_FAST_COMPILE,"O1",
113 "Optimize for linking speed, not execution speed."),
114 clEnumValN(OPT_SIMPLE,"O2",
115 "Perform only required/minimal optimizations"),
116 clEnumValN(OPT_AGGRESSIVE,"O3",
117 "An alias for the -O2 option."),
118 clEnumValN(OPT_LINK_TIME,"O4",
119 "Perform standard link time optimizations"),
120 clEnumValN(OPT_AGGRESSIVE_LINK_TIME,"O5",
121 "Perform aggressive link time optimizations"),
127 /// PrintAndReturn - Prints a message to standard error and returns true.
130 /// progname - The name of the program (i.e. argv[0]).
131 /// Message - The message to print to standard error.
133 static int PrintAndReturn(const char *progname, const std::string &Message) {
134 std::cerr << progname << ": " << Message << "\n";
138 /// EmitShellScript - Output the wrapper file that invokes the JIT on the LLVM
139 /// bytecode file for the program.
140 static void EmitShellScript(char **argv) {
141 #if defined(_WIN32) || defined(__CYGWIN__)
142 // Windows doesn't support #!/bin/sh style shell scripts in .exe files. To
143 // support windows systems, we copy the llvm-stub.exe executable from the
144 // build tree to the destination file.
145 std::string llvmstub = FindExecutable("llvm-stub.exe", argv[0]);
146 if (llvmstub.empty()) {
147 std::cerr << "Could not find llvm-stub.exe executable!\n";
150 if (CopyFile(OutputFilename, llvmstub)) {
151 std::cerr << "Could not copy the llvm-stub.exe executable!\n";
157 // Output the script to start the program...
158 std::ofstream Out2(OutputFilename.c_str());
160 exit(PrintAndReturn(argv[0], "error opening '" + OutputFilename +
163 Out2 << "#!/bin/sh\n";
164 // Allow user to setenv LLVMINTERP if lli is not in their PATH.
165 Out2 << "lli=${LLVMINTERP-lli}\n";
166 Out2 << "exec $lli \\\n";
167 // gcc accepts -l<lib> and implicitly searches /lib and /usr/lib.
168 LibPaths.push_back("/lib");
169 LibPaths.push_back("/usr/lib");
170 LibPaths.push_back("/usr/X11R6/lib");
171 // We don't need to link in libc! In fact, /usr/lib/libc.so may not be a
172 // shared object at all! See RH 8: plain text.
173 std::vector<std::string>::iterator libc =
174 std::find(Libraries.begin(), Libraries.end(), "c");
175 if (libc != Libraries.end()) Libraries.erase(libc);
176 // List all the shared object (native) libraries this executable will need
177 // on the command line, so that we don't have to do this manually!
178 for (std::vector<std::string>::iterator i = Libraries.begin(),
179 e = Libraries.end(); i != e; ++i) {
180 std::string FullLibraryPath = FindLib(*i, LibPaths, true);
181 if (!FullLibraryPath.empty() && IsSharedObject(FullLibraryPath))
182 Out2 << " -load=" << FullLibraryPath << " \\\n";
184 Out2 << " $0.bc ${1+\"$@\"}\n";
188 int main(int argc, char **argv, char **envp) {
189 cl::ParseCommandLineOptions(argc, argv, " llvm linker for GCC\n");
190 sys::PrintStackTraceOnErrorSignal();
192 std::string ModuleID("llvm-ld-output");
193 std::auto_ptr<Module> Composite(new Module(ModuleID));
195 // We always look first in the current directory when searching for libraries.
196 LibPaths.insert(LibPaths.begin(), ".");
198 // If the user specified an extra search path in their environment, respect
200 if (char *SearchPath = getenv("LLVM_LIB_SEARCH_PATH"))
201 LibPaths.push_back(SearchPath);
203 // Remove any consecutive duplicates of the same library...
204 Libraries.erase(std::unique(Libraries.begin(), Libraries.end()),
207 // Link in all of the files
208 if (LinkFiles(argv[0], Composite.get(), InputFilenames, Verbose))
209 return 1; // Error already printed
211 // Link in all of the libraries next...
213 LinkLibraries(argv[0], Composite.get(), Libraries, LibPaths,
216 // Create the output file.
217 std::string RealBytecodeOutput = OutputFilename;
218 if (!LinkAsLibrary) RealBytecodeOutput += ".bc";
219 std::ofstream Out(RealBytecodeOutput.c_str());
221 return PrintAndReturn(argv[0], "error opening '" + RealBytecodeOutput +
224 // Ensure that the bytecode file gets removed from the disk if we get a
225 // terminating signal.
226 sys::RemoveFileOnSignal(sys::Path(RealBytecodeOutput));
228 // Generate the bytecode file.
229 if (GenerateBytecode(Composite.get(), Strip, !NoInternalize, &Out)) {
231 return PrintAndReturn(argv[0], "error generating bytecode");
234 // Close the bytecode file.
237 // If we are not linking a library, generate either a native executable
238 // or a JIT shell script, depending upon what the user wants.
239 if (!LinkAsLibrary) {
240 // If the user wants to generate a native executable, compile it from the
243 // Otherwise, create a script that will run the bytecode through the JIT.
245 // Name of the Assembly Language output file
246 std::string AssemblyFile = OutputFilename + ".s";
248 // Mark the output files for removal if we get an interrupt.
249 sys::RemoveFileOnSignal(sys::Path(AssemblyFile));
250 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
252 // Determine the locations of the llc and gcc programs.
253 std::string llc = FindExecutable("llc", argv[0]);
254 std::string gcc = FindExecutable("gcc", argv[0]);
256 return PrintAndReturn(argv[0], "Failed to find llc");
259 return PrintAndReturn(argv[0], "Failed to find gcc");
261 // Generate an assembly language file for the bytecode.
262 if (Verbose) std::cout << "Generating Assembly Code\n";
263 GenerateAssembly(AssemblyFile, RealBytecodeOutput, llc, envp);
264 if (Verbose) std::cout << "Generating Native Code\n";
265 GenerateNative(OutputFilename, AssemblyFile, Libraries, LibPaths,
268 // Remove the assembly language file.
269 removeFile (AssemblyFile);
270 } else if (NativeCBE) {
271 std::string CFile = OutputFilename + ".cbe.c";
273 // Mark the output files for removal if we get an interrupt.
274 sys::RemoveFileOnSignal(sys::Path(CFile));
275 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
277 // Determine the locations of the llc and gcc programs.
278 std::string llc = FindExecutable("llc", argv[0]);
279 std::string gcc = FindExecutable("gcc", argv[0]);
281 return PrintAndReturn(argv[0], "Failed to find llc");
283 return PrintAndReturn(argv[0], "Failed to find gcc");
285 // Generate an assembly language file for the bytecode.
286 if (Verbose) std::cout << "Generating Assembly Code\n";
287 GenerateCFile(CFile, RealBytecodeOutput, llc, envp);
288 if (Verbose) std::cout << "Generating Native Code\n";
289 GenerateNative(OutputFilename, CFile, Libraries, LibPaths, gcc, envp);
291 // Remove the assembly language file.
295 EmitShellScript(argv);
298 // Make the script executable...
299 MakeFileExecutable(OutputFilename);
301 // Make the bytecode file readable and directly executable in LLEE as well
302 MakeFileExecutable(RealBytecodeOutput);
303 MakeFileReadable(RealBytecodeOutput);