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"
25 #include "Support/CommandLine.h"
29 DisableInline("disable-inlining", cl::desc("Do not run the inliner pass"));
33 /// GenerateBytecode - generates a bytecode file from the specified module.
36 /// M - The module for which bytecode should be generated.
37 /// Strip - Flags whether symbols should be stripped from the output.
38 /// Internalize - Flags whether all symbols should be marked internal.
39 /// Out - Pointer to file stream to which to write the output.
44 /// Returns non-zero value on error.
47 GenerateBytecode (Module *M, bool Strip, bool Internalize, std::ostream *Out) {
48 // In addition to just linking the input from GCC, we also want to spiff it up
49 // a little bit. Do this now.
52 // Add an appropriate TargetData instance for this module...
53 Passes.add(new TargetData("gccld", M));
55 // Linking modules together can lead to duplicated global constants, only keep
56 // one copy of each constant...
57 Passes.add(createConstantMergePass());
59 // If the -s command line option was specified, strip the symbols out of the
60 // resulting program to make it smaller. -s is a GCC option that we are
63 Passes.add(createSymbolStrippingPass());
65 // Often if the programmer does not specify proper prototypes for the
66 // functions they are calling, they end up calling a vararg version of the
67 // function that does not get a body filled in (the real function has typed
68 // arguments). This pass merges the two functions.
69 Passes.add(createFunctionResolvingPass());
72 // Now that composite has been compiled, scan through the module, looking
73 // for a main function. If main is defined, mark all other functions
75 Passes.add(createInternalizePass());
78 // Propagate constants at call sites into the functions they call.
79 Passes.add(createIPConstantPropagationPass());
81 // Remove unused arguments from functions...
82 Passes.add(createDeadArgEliminationPass());
85 Passes.add(createFunctionInliningPass()); // Inline small functions
87 // The FuncResolve pass may leave cruft around if functions were prototyped
88 // differently than they were defined. Remove this cruft.
89 Passes.add(createInstructionCombiningPass());
91 // Delete basic blocks, which optimization passes may have killed...
92 Passes.add(createCFGSimplificationPass());
94 // Now that we have optimized the program, discard unreachable functions...
95 Passes.add(createGlobalDCEPass());
97 // Add the pass that writes bytecode to the output file...
98 Passes.add(new WriteBytecodePass(Out));
100 // Run our queue of passes all at once now, efficiently.
106 /// GenerateAssembly - generates a native assembly language source file from the
107 /// specified bytecode file.
110 /// InputFilename - The name of the output bytecode file.
111 /// OutputFilename - The name of the file to generate.
112 /// llc - The pathname to use for LLC.
113 /// envp - The environment to use when running LLC.
118 /// Return non-zero value on error.
121 GenerateAssembly(const std::string &OutputFilename,
122 const std::string &InputFilename,
123 const std::string &llc,
126 // Run LLC to convert the bytecode file into assembly code.
129 cmd[0] = llc.c_str();
132 cmd[3] = OutputFilename.c_str();
133 cmd[4] = InputFilename.c_str();
136 return ExecWait(cmd, envp);
139 /// GenerateNative - generates a native assembly language source file from the
140 /// specified assembly source file.
143 /// InputFilename - The name of the output bytecode file.
144 /// OutputFilename - The name of the file to generate.
145 /// Libraries - The list of libraries with which to link.
146 /// LibPaths - The list of directories in which to find libraries.
147 /// gcc - The pathname to use for GGC.
148 /// envp - A copy of the process's current environment.
153 /// Returns non-zero value on error.
156 GenerateNative(const std::string &OutputFilename,
157 const std::string &InputFilename,
158 const std::vector<std::string> &Libraries,
159 const std::vector<std::string> &LibPaths,
160 const std::string &gcc,
161 char ** const envp) {
162 // Remove these environment variables from the environment of the
163 // programs that we will execute. It appears that GCC sets these
164 // environment variables so that the programs it uses can configure
165 // themselves identically.
167 // However, when we invoke GCC below, we want it to use its normal
168 // configuration. Hence, we must sanitize its environment.
169 char ** clean_env = CopyEnv(envp);
170 if (clean_env == NULL)
172 RemoveEnv("LIBRARY_PATH", clean_env);
173 RemoveEnv("COLLECT_GCC_OPTIONS", clean_env);
174 RemoveEnv("GCC_EXEC_PREFIX", clean_env);
175 RemoveEnv("COMPILER_PATH", clean_env);
176 RemoveEnv("COLLECT_GCC", clean_env);
178 std::vector<const char *> cmd;
180 // Run GCC to assemble and link the program into native code.
183 // We can't just assemble and link the file with the system assembler
184 // and linker because we don't know where to put the _start symbol.
185 // GCC mysteriously knows how to do it.
186 cmd.push_back(gcc.c_str());
188 cmd.push_back(OutputFilename.c_str());
189 cmd.push_back(InputFilename.c_str());
191 // Adding the library paths creates a problem for native generation. If we
192 // include the search paths from llvmgcc, then we'll be telling normal gcc
193 // to look inside of llvmgcc's library directories for libraries. This is
194 // bad because those libraries hold only bytecode files (not native object
195 // files). In the end, we attempt to link the bytecode libgcc into a native
198 // Add in the library path options.
199 for (unsigned index=0; index < LibPaths.size(); index++) {
201 cmd.push_back(LibPaths[index].c_str());
205 // Add in the libraries to link.
206 std::vector<std::string> Libs(Libraries);
207 for (unsigned index = 0; index < Libs.size(); index++) {
208 Libs[index] = "-l" + Libs[index];
209 cmd.push_back(Libs[index].c_str());
213 // Run the compiler to assembly and link together the program.
214 return ExecWait(&(cmd[0]), clean_env);