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/Analysis/LoadValueNumbering.h"
20 #include "llvm/Analysis/Verifier.h"
21 #include "llvm/Bytecode/WriteBytecodePass.h"
22 #include "llvm/Target/TargetData.h"
23 #include "llvm/Transforms/IPO.h"
24 #include "llvm/Transforms/Scalar.h"
25 #include "llvm/Transforms/Utils/Linker.h"
26 #include "Support/SystemUtils.h"
27 #include "Support/CommandLine.h"
32 DisableInline("disable-inlining", cl::desc("Do not run the inliner pass"));
35 Verify("verify", cl::desc("Verify intermediate results of all passes"));
38 DisableOptimizations("disable-opt",
39 cl::desc("Do not run any optimization passes"));
42 static inline void addPass(PassManager &PM, Pass *P) {
43 // Add the pass to the pass manager...
46 // If we are verifying all of the intermediate steps, add the verifier...
47 if (Verify) PM.add(createVerifierPass());
50 /// GenerateBytecode - generates a bytecode file from the specified module.
53 /// M - The module for which bytecode should be generated.
54 /// Strip - Flags whether symbols should be stripped from the output.
55 /// Internalize - Flags whether all symbols should be marked internal.
56 /// Out - Pointer to file stream to which to write the output.
58 /// Returns non-zero value on error.
60 int llvm::GenerateBytecode(Module *M, bool Strip, bool Internalize,
62 // In addition to just linking the input from GCC, we also want to spiff it up
63 // a little bit. Do this now.
66 if (Verify) Passes.add(createVerifierPass());
68 // Add an appropriate TargetData instance for this module...
69 addPass(Passes, new TargetData("gccld", M));
71 // Often if the programmer does not specify proper prototypes for the
72 // functions they are calling, they end up calling a vararg version of the
73 // function that does not get a body filled in (the real function has typed
74 // arguments). This pass merges the two functions.
75 addPass(Passes, createFunctionResolvingPass());
77 if (!DisableOptimizations) {
79 // Now that composite has been compiled, scan through the module, looking
80 // for a main function. If main is defined, mark all other functions
82 addPass(Passes, createInternalizePass());
85 // Now that we internalized some globals, see if we can mark any globals as
87 addPass(Passes, createGlobalConstifierPass());
89 // Linking modules together can lead to duplicated global constants, only
90 // keep one copy of each constant...
91 addPass(Passes, createConstantMergePass());
93 // If the -s command line option was specified, strip the symbols out of the
94 // resulting program to make it smaller. -s is a GCC option that we are
97 addPass(Passes, createSymbolStrippingPass());
99 // Propagate constants at call sites into the functions they call.
100 addPass(Passes, createIPConstantPropagationPass());
102 // Remove unused arguments from functions...
103 addPass(Passes, createDeadArgEliminationPass());
106 addPass(Passes, createFunctionInliningPass()); // Inline small functions
108 // If we didn't decide to inline a function, check to see if we can
109 // transform it to pass arguments by value instead of by reference.
110 addPass(Passes, createArgumentPromotionPass());
112 // The IPO passes may leave cruft around. Clean up after them.
113 addPass(Passes, createInstructionCombiningPass());
115 addPass(Passes, createScalarReplAggregatesPass()); // Break up allocas
117 // Run a few AA driven optimizations here and now, to cleanup the code.
118 // Eventually we should put an IP AA in place here.
120 addPass(Passes, createLICMPass()); // Hoist loop invariants
121 addPass(Passes, createLoadValueNumberingPass()); // GVN for load instrs
122 addPass(Passes, createGCSEPass()); // Remove common subexprs
124 // Cleanup and simplify the code after the scalar optimizations.
125 addPass(Passes, createInstructionCombiningPass());
127 // Delete basic blocks, which optimization passes may have killed...
128 addPass(Passes, createCFGSimplificationPass());
130 // Now that we have optimized the program, discard unreachable functions...
131 addPass(Passes, createGlobalDCEPass());
134 // Make sure everything is still good.
135 Passes.add(createVerifierPass());
137 // Add the pass that writes bytecode to the output file...
138 addPass(Passes, new WriteBytecodePass(Out));
140 // Run our queue of passes all at once now, efficiently.
146 /// GenerateAssembly - generates a native assembly language source file from the
147 /// specified bytecode file.
150 /// InputFilename - The name of the output bytecode file.
151 /// OutputFilename - The name of the file to generate.
152 /// llc - The pathname to use for LLC.
153 /// envp - The environment to use when running LLC.
155 /// Return non-zero value on error.
157 int llvm::GenerateAssembly(const std::string &OutputFilename,
158 const std::string &InputFilename,
159 const std::string &llc,
160 char ** const envp) {
161 // Run LLC to convert the bytecode file into assembly code.
163 cmd[0] = llc.c_str();
166 cmd[3] = OutputFilename.c_str();
167 cmd[4] = InputFilename.c_str();
170 return ExecWait(cmd, envp);
173 /// GenerateAssembly - generates a native assembly language source file from the
174 /// specified bytecode file.
175 int llvm::GenerateCFile(const std::string &OutputFile,
176 const std::string &InputFile,
177 const std::string &llc, char ** const envp) {
178 // Run LLC to convert the bytecode file into C.
181 cmd[0] = llc.c_str();
185 cmd[4] = OutputFile.c_str();
186 cmd[5] = InputFile.c_str();
188 return ExecWait(cmd, envp);
191 /// GenerateNative - generates a native assembly language source file from the
192 /// specified assembly source file.
195 /// InputFilename - The name of the output bytecode file.
196 /// OutputFilename - The name of the file to generate.
197 /// Libraries - The list of libraries with which to link.
198 /// LibPaths - The list of directories in which to find libraries.
199 /// gcc - The pathname to use for GGC.
200 /// envp - A copy of the process's current environment.
205 /// Returns non-zero value on error.
207 int llvm::GenerateNative(const std::string &OutputFilename,
208 const std::string &InputFilename,
209 const std::vector<std::string> &Libraries,
210 const std::vector<std::string> &LibPaths,
211 const std::string &gcc, char ** const envp) {
212 // Remove these environment variables from the environment of the
213 // programs that we will execute. It appears that GCC sets these
214 // environment variables so that the programs it uses can configure
215 // themselves identically.
217 // However, when we invoke GCC below, we want it to use its normal
218 // configuration. Hence, we must sanitize its environment.
219 char ** clean_env = CopyEnv(envp);
220 if (clean_env == NULL)
222 RemoveEnv("LIBRARY_PATH", clean_env);
223 RemoveEnv("COLLECT_GCC_OPTIONS", clean_env);
224 RemoveEnv("GCC_EXEC_PREFIX", clean_env);
225 RemoveEnv("COMPILER_PATH", clean_env);
226 RemoveEnv("COLLECT_GCC", clean_env);
228 std::vector<const char *> cmd;
230 // Run GCC to assemble and link the program into native code.
233 // We can't just assemble and link the file with the system assembler
234 // and linker because we don't know where to put the _start symbol.
235 // GCC mysteriously knows how to do it.
236 cmd.push_back(gcc.c_str());
237 cmd.push_back("-O3");
239 cmd.push_back(OutputFilename.c_str());
240 cmd.push_back(InputFilename.c_str());
242 // Adding the library paths creates a problem for native generation. If we
243 // include the search paths from llvmgcc, then we'll be telling normal gcc
244 // to look inside of llvmgcc's library directories for libraries. This is
245 // bad because those libraries hold only bytecode files (not native object
246 // files). In the end, we attempt to link the bytecode libgcc into a native
249 // Add in the library path options.
250 for (unsigned index=0; index < LibPaths.size(); index++) {
252 cmd.push_back(LibPaths[index].c_str());
256 // Add in the libraries to link.
257 std::vector<std::string> Libs(Libraries);
258 for (unsigned index = 0; index < Libs.size(); index++) {
259 if (Libs[index] != "crtend") {
260 Libs[index] = "-l" + Libs[index];
261 cmd.push_back(Libs[index].c_str());
266 // Run the compiler to assembly and link together the program.
267 return ExecWait(&(cmd[0]), clean_env);