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