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