1 //===----------------------------------------------------------------------===//
2 // LLVM 'GCCLD' UTILITY
4 // This utility is intended to be compatible with GCC, and follows standard
5 // system ld conventions. As such, the default output file is ./a.out.
6 // Additionally, this program outputs a shell script that is used to invoke LLI
7 // to execute the program. In this manner, the generated executable (a.out for
8 // example), is directly executable, whereas the bytecode file actually lives in
9 // the a.out.bc file generated by this program. Also, Force is on by default.
11 // Note that if someone (or a script) deletes the executable program generated,
12 // the .bc file will be left around. Considering that this is a temporary hack,
13 // I'm not to worried about this.
15 //===----------------------------------------------------------------------===//
17 #include "llvm/Transforms/Utils/Linker.h"
18 #include "llvm/Module.h"
19 #include "llvm/PassManager.h"
20 #include "llvm/Bytecode/Reader.h"
21 #include "llvm/Bytecode/WriteBytecodePass.h"
22 #include "llvm/Transforms/IPO.h"
23 #include "llvm/Transforms/Scalar.h"
24 #include "Support/CommandLine.h"
25 #include "Support/Signals.h"
29 #include <sys/types.h> // For FileExists
34 InputFilenames(cl::Positional, cl::desc("<input bytecode files>"),
38 OutputFilename("o", cl::desc("Override output filename"), cl::init("a.out"),
39 cl::value_desc("filename"));
42 Verbose("v", cl::desc("Print information about actions taken"));
45 LibPaths("L", cl::desc("Specify a library search path"), cl::Prefix,
46 cl::value_desc("directory"));
49 Libraries("l", cl::desc("Specify libraries to link to"), cl::Prefix,
50 cl::value_desc("library prefix"));
53 Strip("s", cl::desc("Strip symbol info from executable"));
56 NoInternalize("disable-internalize",
57 cl::desc("Do not mark all symbols as internal"));
59 // Compatibility options that are ignored, but support by LD
61 CO3("soname", cl::Hidden, cl::desc("Compatibility option: ignored"));
63 CO4("version-script", cl::Hidden, cl::desc("Compatibility option: ignored"));
65 CO5("eh-frame-hdr", cl::Hidden, cl::desc("Compatibility option: ignored"));
68 // FileExists - Return true if the specified string is an openable file...
69 static inline bool FileExists(const std::string &FN) {
71 return stat(FN.c_str(), &StatBuf) != -1;
74 // LoadFile - Read the specified bytecode file in and return it. This routine
75 // searches the link path for the specified file to try to find it...
77 static inline std::auto_ptr<Module> LoadFile(const std::string &FN) {
78 std::string Filename = FN;
79 std::string ErrorMessage;
81 unsigned NextLibPathIdx = 0;
82 bool FoundAFile = false;
85 if (Verbose) std::cerr << "Loading '" << Filename << "'\n";
86 if (FileExists(Filename)) FoundAFile = true;
87 Module *Result = ParseBytecodeFile(Filename, &ErrorMessage);
88 if (Result) return std::auto_ptr<Module>(Result); // Load successful!
91 std::cerr << "Error opening bytecode file: '" << Filename << "'";
92 if (ErrorMessage.size()) std::cerr << ": " << ErrorMessage;
96 if (NextLibPathIdx == LibPaths.size()) break;
97 Filename = LibPaths[NextLibPathIdx++] + "/" + FN;
101 std::cerr << "Bytecode file '" << FN << "' corrupt! "
102 << "Use 'gccld -v ...' for more info.\n";
104 std::cerr << "Could not locate bytecode file: '" << FN << "'\n";
105 return std::auto_ptr<Module>();
109 int main(int argc, char **argv) {
110 cl::ParseCommandLineOptions(argc, argv, " llvm linker for GCC\n");
112 unsigned BaseArg = 0;
113 std::string ErrorMessage;
115 if (!Libraries.empty()) {
116 // Sort libraries list...
117 std::sort(Libraries.begin(), Libraries.end());
119 // Remove duplicate libraries entries...
120 Libraries.erase(unique(Libraries.begin(), Libraries.end()),
123 // Add all of the libraries to the end of the link line...
124 for (unsigned i = 0; i < Libraries.size(); ++i)
125 InputFilenames.push_back("lib" + Libraries[i] + ".bc");
128 std::auto_ptr<Module> Composite(LoadFile(InputFilenames[BaseArg]));
129 if (Composite.get() == 0) return 1;
131 for (unsigned i = BaseArg+1; i < InputFilenames.size(); ++i) {
132 std::auto_ptr<Module> M(LoadFile(InputFilenames[i]));
133 if (M.get() == 0) return 1;
135 if (Verbose) std::cerr << "Linking in '" << InputFilenames[i] << "'\n";
137 if (LinkModules(Composite.get(), M.get(), &ErrorMessage)) {
138 std::cerr << argv[0] << ": error linking in '" << InputFilenames[i]
139 << "': " << ErrorMessage << "\n";
144 // In addition to just linking the input from GCC, we also want to spiff it up
145 // a little bit. Do this now.
149 // Linking modules together can lead to duplicated global constants, only keep
150 // one copy of each constant...
152 Passes.add(createConstantMergePass());
154 // If the -s command line option was specified, strip the symbols out of the
155 // resulting program to make it smaller. -s is a GCC option that we are
159 Passes.add(createSymbolStrippingPass());
161 // Often if the programmer does not specify proper prototypes for the
162 // functions they are calling, they end up calling a vararg version of the
163 // function that does not get a body filled in (the real function has typed
164 // arguments). This pass merges the two functions.
166 Passes.add(createFunctionResolvingPass());
168 if (!NoInternalize) {
169 // Now that composite has been compiled, scan through the module, looking
170 // for a main function. If main is defined, mark all other functions
173 Passes.add(createInternalizePass());
176 // Now that we have optimized the program, discard unreachable functions...
178 Passes.add(createGlobalDCEPass());
180 // Add the pass that writes bytecode to the output file...
181 std::ofstream Out((OutputFilename+".bc").c_str());
183 std::cerr << argv[0] << ": error opening '" << OutputFilename
184 << ".bc' for writing!\n";
187 Passes.add(new WriteBytecodePass(&Out)); // Write bytecode to file...
189 // Make sure that the Out file gets unlink'd from the disk if we get a SIGINT
190 RemoveFileOnSignal(OutputFilename+".bc");
192 // Run our queue of passes all at once now, efficiently.
193 Passes.run(*Composite.get());
196 // Output the script to start the program...
197 std::ofstream Out2(OutputFilename.c_str());
199 std::cerr << argv[0] << ": error opening '" << OutputFilename
200 << "' for writing!\n";
203 Out2 << "#!/bin/sh\nlli -q -abort-on-exception $0.bc $*\n";
206 // Make the script executable...
207 chmod(OutputFilename.c_str(), 0755);