1 //===- OptimizerDriver.cpp - Allow BugPoint to run passes safely ----------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines an interface that allows bugpoint to run various passes
11 // without the threat of a buggy pass corrupting bugpoint (of course, bugpoint
12 // may have its own bugs, but that's another story...). It achieves this by
13 // forking a copy of itself and having the child process do the optimizations.
14 // If this client dies, we can always fork a new one. :)
15 //
16 //===----------------------------------------------------------------------===//
17
18 #include "BugDriver.h"
19 #include "llvm/Analysis/Verifier.h"
20 #include "llvm/Bitcode/ReaderWriter.h"
21 #include "llvm/IR/DataLayout.h"
22 #include "llvm/IR/Module.h"
23 #include "llvm/PassManager.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/Debug.h"
26 #include "llvm/Support/FileUtilities.h"
27 #include "llvm/Support/Path.h"
28 #include "llvm/Support/Program.h"
29 #include "llvm/Support/SystemUtils.h"
30 #include "llvm/Support/ToolOutputFile.h"
31
32 #define DONT_GET_PLUGIN_LOADER_OPTION
33 #include "llvm/Support/PluginLoader.h"
34
35 #include <fstream>
36
37 using namespace llvm;
38
39 namespace llvm {
40 extern cl::opt<std::string> OutputPrefix;
41 }
42
43 namespace {
44 // ChildOutput - This option captures the name of the child output file that
45 // is set up by the parent bugpoint process
46 cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
47 cl::opt<std::string> OptCmd("opt-command", cl::init(""),
48 cl::desc("Path to opt. (default: search path "
49 "for 'opt'.)"));
50 }
51
52 /// writeProgramToFile - This writes the current "Program" to the named bitcode
53 /// file. If an error occurs, true is returned.
54 ///
writeProgramToFileAux(tool_output_file & Out,const Module * M)55 static bool writeProgramToFileAux(tool_output_file &Out, const Module *M) {
56 WriteBitcodeToFile(M, Out.os());
57 Out.os().close();
58 if (!Out.os().has_error()) {
59 Out.keep();
60 return false;
61 }
62 return true;
63 }
64
writeProgramToFile(const std::string & Filename,int FD,const Module * M) const65 bool BugDriver::writeProgramToFile(const std::string &Filename, int FD,
66 const Module *M) const {
67 tool_output_file Out(Filename.c_str(), FD);
68 return writeProgramToFileAux(Out, M);
69 }
70
writeProgramToFile(const std::string & Filename,const Module * M) const71 bool BugDriver::writeProgramToFile(const std::string &Filename,
72 const Module *M) const {
73 std::string ErrInfo;
74 tool_output_file Out(Filename.c_str(), ErrInfo, sys::fs::F_Binary);
75 if (ErrInfo.empty())
76 return writeProgramToFileAux(Out, M);
77 return true;
78 }
79
80
81 /// EmitProgressBitcode - This function is used to output the current Program
82 /// to a file named "bugpoint-ID.bc".
83 ///
EmitProgressBitcode(const Module * M,const std::string & ID,bool NoFlyer) const84 void BugDriver::EmitProgressBitcode(const Module *M,
85 const std::string &ID,
86 bool NoFlyer) const {
87 // Output the input to the current pass to a bitcode file, emit a message
88 // telling the user how to reproduce it: opt -foo blah.bc
89 //
90 std::string Filename = OutputPrefix + "-" + ID + ".bc";
91 if (writeProgramToFile(Filename, M)) {
92 errs() << "Error opening file '" << Filename << "' for writing!\n";
93 return;
94 }
95
96 outs() << "Emitted bitcode to '" << Filename << "'\n";
97 if (NoFlyer || PassesToRun.empty()) return;
98 outs() << "\n*** You can reproduce the problem with: ";
99 if (UseValgrind) outs() << "valgrind ";
100 outs() << "opt " << Filename;
101 for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
102 outs() << " -load " << PluginLoader::getPlugin(i);
103 }
104 outs() << " " << getPassesString(PassesToRun) << "\n";
105 }
106
107 cl::opt<bool> SilencePasses("silence-passes",
108 cl::desc("Suppress output of running passes (both stdout and stderr)"));
109
110 static cl::list<std::string> OptArgs("opt-args", cl::Positional,
111 cl::desc("<opt arguments>..."),
112 cl::ZeroOrMore, cl::PositionalEatsArgs);
113
114 /// runPasses - Run the specified passes on Program, outputting a bitcode file
115 /// and writing the filename into OutputFile if successful. If the
116 /// optimizations fail for some reason (optimizer crashes), return true,
117 /// otherwise return false. If DeleteOutput is set to true, the bitcode is
118 /// deleted on success, and the filename string is undefined. This prints to
119 /// outs() a single line message indicating whether compilation was successful
120 /// or failed.
121 ///
runPasses(Module * Program,const std::vector<std::string> & Passes,std::string & OutputFilename,bool DeleteOutput,bool Quiet,unsigned NumExtraArgs,const char * const * ExtraArgs) const122 bool BugDriver::runPasses(Module *Program,
123 const std::vector<std::string> &Passes,
124 std::string &OutputFilename, bool DeleteOutput,
125 bool Quiet, unsigned NumExtraArgs,
126 const char * const *ExtraArgs) const {
127 // setup the output file name
128 outs().flush();
129 SmallString<128> UniqueFilename;
130 error_code EC = sys::fs::createUniqueFile(
131 OutputPrefix + "-output-%%%%%%%.bc", UniqueFilename);
132 if (EC) {
133 errs() << getToolName() << ": Error making unique filename: "
134 << EC.message() << "\n";
135 return 1;
136 }
137 OutputFilename = UniqueFilename.str();
138
139 // set up the input file name
140 SmallString<128> InputFilename;
141 int InputFD;
142 EC = sys::fs::createUniqueFile(OutputPrefix + "-input-%%%%%%%.bc", InputFD,
143 InputFilename);
144 if (EC) {
145 errs() << getToolName() << ": Error making unique filename: "
146 << EC.message() << "\n";
147 return 1;
148 }
149
150 tool_output_file InFile(InputFilename.c_str(), InputFD);
151
152 WriteBitcodeToFile(Program, InFile.os());
153 InFile.os().close();
154 if (InFile.os().has_error()) {
155 errs() << "Error writing bitcode file: " << InputFilename << "\n";
156 InFile.os().clear_error();
157 return 1;
158 }
159
160 std::string tool = OptCmd.empty()? sys::FindProgramByName("opt") : OptCmd;
161 if (tool.empty()) {
162 errs() << "Cannot find `opt' in PATH!\n";
163 return 1;
164 }
165
166 // Ok, everything that could go wrong before running opt is done.
167 InFile.keep();
168
169 // setup the child process' arguments
170 SmallVector<const char*, 8> Args;
171 if (UseValgrind) {
172 Args.push_back("valgrind");
173 Args.push_back("--error-exitcode=1");
174 Args.push_back("-q");
175 Args.push_back(tool.c_str());
176 } else
177 Args.push_back(tool.c_str());
178
179 Args.push_back("-o");
180 Args.push_back(OutputFilename.c_str());
181 for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
182 Args.push_back(OptArgs[i].c_str());
183 std::vector<std::string> pass_args;
184 for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
185 pass_args.push_back( std::string("-load"));
186 pass_args.push_back( PluginLoader::getPlugin(i));
187 }
188 for (std::vector<std::string>::const_iterator I = Passes.begin(),
189 E = Passes.end(); I != E; ++I )
190 pass_args.push_back( std::string("-") + (*I) );
191 for (std::vector<std::string>::const_iterator I = pass_args.begin(),
192 E = pass_args.end(); I != E; ++I )
193 Args.push_back(I->c_str());
194 Args.push_back(InputFilename.c_str());
195 for (unsigned i = 0; i < NumExtraArgs; ++i)
196 Args.push_back(*ExtraArgs);
197 Args.push_back(0);
198
199 DEBUG(errs() << "\nAbout to run:\t";
200 for (unsigned i = 0, e = Args.size()-1; i != e; ++i)
201 errs() << " " << Args[i];
202 errs() << "\n";
203 );
204
205 std::string Prog;
206 if (UseValgrind)
207 Prog = sys::FindProgramByName("valgrind");
208 else
209 Prog = tool;
210
211 // Redirect stdout and stderr to nowhere if SilencePasses is given
212 StringRef Nowhere;
213 const StringRef *Redirects[3] = {0, &Nowhere, &Nowhere};
214
215 std::string ErrMsg;
216 int result = sys::ExecuteAndWait(Prog, Args.data(), 0,
217 (SilencePasses ? Redirects : 0), Timeout,
218 MemoryLimit, &ErrMsg);
219
220 // If we are supposed to delete the bitcode file or if the passes crashed,
221 // remove it now. This may fail if the file was never created, but that's ok.
222 if (DeleteOutput || result != 0)
223 sys::fs::remove(OutputFilename);
224
225 // Remove the temporary input file as well
226 sys::fs::remove(InputFilename.c_str());
227
228 if (!Quiet) {
229 if (result == 0)
230 outs() << "Success!\n";
231 else if (result > 0)
232 outs() << "Exited with error code '" << result << "'\n";
233 else if (result < 0) {
234 if (result == -1)
235 outs() << "Execute failed: " << ErrMsg << "\n";
236 else
237 outs() << "Crashed: " << ErrMsg << "\n";
238 }
239 if (result & 0x01000000)
240 outs() << "Dumped core\n";
241 }
242
243 // Was the child successful?
244 return result != 0;
245 }
246
247
248 /// runPassesOn - Carefully run the specified set of pass on the specified
249 /// module, returning the transformed module on success, or a null pointer on
250 /// failure.
runPassesOn(Module * M,const std::vector<std::string> & Passes,bool AutoDebugCrashes,unsigned NumExtraArgs,const char * const * ExtraArgs)251 Module *BugDriver::runPassesOn(Module *M,
252 const std::vector<std::string> &Passes,
253 bool AutoDebugCrashes, unsigned NumExtraArgs,
254 const char * const *ExtraArgs) {
255 std::string BitcodeResult;
256 if (runPasses(M, Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
257 NumExtraArgs, ExtraArgs)) {
258 if (AutoDebugCrashes) {
259 errs() << " Error running this sequence of passes"
260 << " on the input program!\n";
261 delete swapProgramIn(M);
262 EmitProgressBitcode(M, "pass-error", false);
263 exit(debugOptimizerCrash());
264 }
265 return 0;
266 }
267
268 Module *Ret = ParseInputFile(BitcodeResult, Context);
269 if (Ret == 0) {
270 errs() << getToolName() << ": Error reading bitcode file '"
271 << BitcodeResult << "'!\n";
272 exit(1);
273 }
274 sys::fs::remove(BitcodeResult);
275 return Ret;
276 }
277