1 //===- GenerateCode.cpp - Functions for generating executable files ------===//
3 // This file contains functions for generating executable files once linking
4 // has finished. This includes generating a shell script to run the JIT or
5 // a native executable derived from the bytecode.
7 //===----------------------------------------------------------------------===//
10 #include "llvm/Module.h"
11 #include "llvm/PassManager.h"
12 #include "llvm/Bytecode/WriteBytecodePass.h"
13 #include "llvm/Target/TargetData.h"
14 #include "llvm/Transforms/IPO.h"
15 #include "llvm/Transforms/Scalar.h"
16 #include "llvm/Transforms/Utils/Linker.h"
17 #include "Support/SystemUtils.h"
19 /// GenerateBytecode - generates a bytecode file from the specified module.
22 /// M - The module for which bytecode should be generated.
23 /// Strip - Flags whether symbols should be stripped from the output.
24 /// Internalize - Flags whether all symbols should be marked internal.
25 /// Out - Pointer to file stream to which to write the output.
30 /// Returns non-zero value on error.
33 GenerateBytecode (Module *M, bool Strip, bool Internalize, std::ostream *Out) {
34 // In addition to just linking the input from GCC, we also want to spiff it up
35 // a little bit. Do this now.
38 // Add an appropriate TargetData instance for this module...
39 Passes.add(new TargetData("gccld", M));
41 // Linking modules together can lead to duplicated global constants, only keep
42 // one copy of each constant...
43 Passes.add(createConstantMergePass());
45 // If the -s command line option was specified, strip the symbols out of the
46 // resulting program to make it smaller. -s is a GCC option that we are
49 Passes.add(createSymbolStrippingPass());
51 // Often if the programmer does not specify proper prototypes for the
52 // functions they are calling, they end up calling a vararg version of the
53 // function that does not get a body filled in (the real function has typed
54 // arguments). This pass merges the two functions.
55 Passes.add(createFunctionResolvingPass());
58 // Now that composite has been compiled, scan through the module, looking
59 // for a main function. If main is defined, mark all other functions
61 Passes.add(createInternalizePass());
64 // Remove unused arguments from functions...
65 Passes.add(createDeadArgEliminationPass());
67 // The FuncResolve pass may leave cruft around if functions were prototyped
68 // differently than they were defined. Remove this cruft.
69 Passes.add(createInstructionCombiningPass());
71 // Delete basic blocks, which optimization passes may have killed...
72 Passes.add(createCFGSimplificationPass());
74 // Now that we have optimized the program, discard unreachable functions...
75 Passes.add(createGlobalDCEPass());
77 // Add the pass that writes bytecode to the output file...
78 Passes.add(new WriteBytecodePass(Out));
80 // Run our queue of passes all at once now, efficiently.
86 /// GenerateAssembly - generates a native assembly language source file from the
87 /// specified bytecode file.
90 /// InputFilename - The name of the output bytecode file.
91 /// OutputFilename - The name of the file to generate.
92 /// llc - The pathname to use for LLC.
93 /// envp - The environment to use when running LLC.
98 /// Return non-zero value on error.
101 GenerateAssembly(const std::string &OutputFilename,
102 const std::string &InputFilename,
103 const std::string &llc,
106 // Run LLC to convert the bytecode file into assembly code.
109 cmd[0] = llc.c_str();
112 cmd[3] = OutputFilename.c_str();
113 cmd[4] = InputFilename.c_str();
116 return ExecWait(cmd, envp);
119 /// GenerateNative - generates a native assembly language source file from the
120 /// specified assembly source file.
123 /// InputFilename - The name of the output bytecode file.
124 /// OutputFilename - The name of the file to generate.
125 /// Libraries - The list of libraries with which to link.
126 /// LibPaths - The list of directories in which to find libraries.
127 /// gcc - The pathname to use for GGC.
128 /// envp - A copy of the process's current environment.
133 /// Returns non-zero value on error.
136 GenerateNative(const std::string &OutputFilename,
137 const std::string &InputFilename,
138 const std::vector<std::string> &Libraries,
139 const std::vector<std::string> &LibPaths,
140 const std::string &gcc,
141 char ** const envp) {
142 // Remove these environment variables from the environment of the
143 // programs that we will execute. It appears that GCC sets these
144 // environment variables so that the programs it uses can configure
145 // themselves identically.
147 // However, when we invoke GCC below, we want it to use its normal
148 // configuration. Hence, we must sanitize its environment.
149 char ** clean_env = CopyEnv(envp);
150 if (clean_env == NULL)
152 RemoveEnv("LIBRARY_PATH", clean_env);
153 RemoveEnv("COLLECT_GCC_OPTIONS", clean_env);
154 RemoveEnv("GCC_EXEC_PREFIX", clean_env);
155 RemoveEnv("COMPILER_PATH", clean_env);
156 RemoveEnv("COLLECT_GCC", clean_env);
158 std::vector<const char *> cmd;
160 // Run GCC to assemble and link the program into native code.
163 // We can't just assemble and link the file with the system assembler
164 // and linker because we don't know where to put the _start symbol.
165 // GCC mysteriously knows how to do it.
166 cmd.push_back(gcc.c_str());
168 cmd.push_back(OutputFilename.c_str());
169 cmd.push_back(InputFilename.c_str());
171 // Adding the library paths creates a problem for native generation. If we
172 // include the search paths from llvmgcc, then we'll be telling normal gcc
173 // to look inside of llvmgcc's library directories for libraries. This is
174 // bad because those libraries hold only bytecode files (not native object
175 // files). In the end, we attempt to link the bytecode libgcc into a native
178 // Add in the library path options.
179 for (unsigned index=0; index < LibPaths.size(); index++) {
181 cmd.push_back(LibPaths[index].c_str());
185 // Add in the libraries to link.
186 std::vector<std::string> Libs(Libraries);
187 for (unsigned index = 0; index < Libs.size(); index++) {
188 Libs[index] = "-l" + Libs[index];
189 cmd.push_back(Libs[index].c_str());
193 // Run the compiler to assembly and link together the program.
194 return ExecWait(&(cmd[0]), clean_env);