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/Module.h"
20 #include "llvm/PassManager.h"
21 #include "llvm/Analysis/Verifier.h"
22 #include "llvm/Bitcode/ReaderWriter.h"
23 #include "llvm/Target/TargetData.h"
24 #include "llvm/Support/FileUtilities.h"
25 #include "llvm/Support/CommandLine.h"
26 #include "llvm/Support/SystemUtils.h"
27 #include "llvm/Support/Debug.h"
28 #include "llvm/Support/ToolOutputFile.h"
29 #include "llvm/Support/Path.h"
30 #include "llvm/Support/Program.h"
31
32 #define DONT_GET_PLUGIN_LOADER_OPTION
33 #include "llvm/Support/PluginLoader.h"
34
35 #include <fstream>
36 using namespace llvm;
37
38 namespace llvm {
39 extern cl::opt<std::string> OutputPrefix;
40 }
41
42 namespace {
43 // ChildOutput - This option captures the name of the child output file that
44 // is set up by the parent bugpoint process
45 cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
46 }
47
48 /// writeProgramToFile - This writes the current "Program" to the named bitcode
49 /// file. If an error occurs, true is returned.
50 ///
writeProgramToFile(const std::string & Filename,const Module * M) const51 bool BugDriver::writeProgramToFile(const std::string &Filename,
52 const Module *M) const {
53 std::string ErrInfo;
54 tool_output_file Out(Filename.c_str(), ErrInfo,
55 raw_fd_ostream::F_Binary);
56 if (ErrInfo.empty()) {
57 WriteBitcodeToFile(M, Out.os());
58 Out.os().close();
59 if (!Out.os().has_error()) {
60 Out.keep();
61 return false;
62 }
63 }
64 Out.os().clear_error();
65 return true;
66 }
67
68
69 /// EmitProgressBitcode - This function is used to output the current Program
70 /// to a file named "bugpoint-ID.bc".
71 ///
EmitProgressBitcode(const Module * M,const std::string & ID,bool NoFlyer) const72 void BugDriver::EmitProgressBitcode(const Module *M,
73 const std::string &ID,
74 bool NoFlyer) const {
75 // Output the input to the current pass to a bitcode file, emit a message
76 // telling the user how to reproduce it: opt -foo blah.bc
77 //
78 std::string Filename = OutputPrefix + "-" + ID + ".bc";
79 if (writeProgramToFile(Filename, M)) {
80 errs() << "Error opening file '" << Filename << "' for writing!\n";
81 return;
82 }
83
84 outs() << "Emitted bitcode to '" << Filename << "'\n";
85 if (NoFlyer || PassesToRun.empty()) return;
86 outs() << "\n*** You can reproduce the problem with: ";
87 if (UseValgrind) outs() << "valgrind ";
88 outs() << "opt " << Filename;
89 for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
90 outs() << " -load " << PluginLoader::getPlugin(i);
91 }
92 outs() << " " << getPassesString(PassesToRun) << "\n";
93 }
94
95 cl::opt<bool> SilencePasses("silence-passes",
96 cl::desc("Suppress output of running passes (both stdout and stderr)"));
97
98 static cl::list<std::string> OptArgs("opt-args", cl::Positional,
99 cl::desc("<opt arguments>..."),
100 cl::ZeroOrMore, cl::PositionalEatsArgs);
101
102 /// runPasses - Run the specified passes on Program, outputting a bitcode file
103 /// and writing the filename into OutputFile if successful. If the
104 /// optimizations fail for some reason (optimizer crashes), return true,
105 /// otherwise return false. If DeleteOutput is set to true, the bitcode is
106 /// deleted on success, and the filename string is undefined. This prints to
107 /// outs() a single line message indicating whether compilation was successful
108 /// or failed.
109 ///
runPasses(Module * Program,const std::vector<std::string> & Passes,std::string & OutputFilename,bool DeleteOutput,bool Quiet,unsigned NumExtraArgs,const char * const * ExtraArgs) const110 bool BugDriver::runPasses(Module *Program,
111 const std::vector<std::string> &Passes,
112 std::string &OutputFilename, bool DeleteOutput,
113 bool Quiet, unsigned NumExtraArgs,
114 const char * const *ExtraArgs) const {
115 // setup the output file name
116 outs().flush();
117 sys::Path uniqueFilename(OutputPrefix + "-output.bc");
118 std::string ErrMsg;
119 if (uniqueFilename.makeUnique(true, &ErrMsg)) {
120 errs() << getToolName() << ": Error making unique filename: "
121 << ErrMsg << "\n";
122 return(1);
123 }
124 OutputFilename = uniqueFilename.str();
125
126 // set up the input file name
127 sys::Path inputFilename(OutputPrefix + "-input.bc");
128 if (inputFilename.makeUnique(true, &ErrMsg)) {
129 errs() << getToolName() << ": Error making unique filename: "
130 << ErrMsg << "\n";
131 return(1);
132 }
133
134 std::string ErrInfo;
135 tool_output_file InFile(inputFilename.c_str(), ErrInfo,
136 raw_fd_ostream::F_Binary);
137
138
139 if (!ErrInfo.empty()) {
140 errs() << "Error opening bitcode file: " << inputFilename.str() << "\n";
141 return 1;
142 }
143 WriteBitcodeToFile(Program, InFile.os());
144 InFile.os().close();
145 if (InFile.os().has_error()) {
146 errs() << "Error writing bitcode file: " << inputFilename.str() << "\n";
147 InFile.os().clear_error();
148 return 1;
149 }
150
151 sys::Path tool = sys::Program::FindProgramByName("opt");
152 if (tool.empty()) {
153 errs() << "Cannot find `opt' in PATH!\n";
154 return 1;
155 }
156
157 // Ok, everything that could go wrong before running opt is done.
158 InFile.keep();
159
160 // setup the child process' arguments
161 SmallVector<const char*, 8> Args;
162 std::string Opt = tool.str();
163 if (UseValgrind) {
164 Args.push_back("valgrind");
165 Args.push_back("--error-exitcode=1");
166 Args.push_back("-q");
167 Args.push_back(tool.c_str());
168 } else
169 Args.push_back(Opt.c_str());
170
171 Args.push_back("-o");
172 Args.push_back(OutputFilename.c_str());
173 for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
174 Args.push_back(OptArgs[i].c_str());
175 std::vector<std::string> pass_args;
176 for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
177 pass_args.push_back( std::string("-load"));
178 pass_args.push_back( PluginLoader::getPlugin(i));
179 }
180 for (std::vector<std::string>::const_iterator I = Passes.begin(),
181 E = Passes.end(); I != E; ++I )
182 pass_args.push_back( std::string("-") + (*I) );
183 for (std::vector<std::string>::const_iterator I = pass_args.begin(),
184 E = pass_args.end(); I != E; ++I )
185 Args.push_back(I->c_str());
186 Args.push_back(inputFilename.c_str());
187 for (unsigned i = 0; i < NumExtraArgs; ++i)
188 Args.push_back(*ExtraArgs);
189 Args.push_back(0);
190
191 DEBUG(errs() << "\nAbout to run:\t";
192 for (unsigned i = 0, e = Args.size()-1; i != e; ++i)
193 errs() << " " << Args[i];
194 errs() << "\n";
195 );
196
197 sys::Path prog;
198 if (UseValgrind)
199 prog = sys::Program::FindProgramByName("valgrind");
200 else
201 prog = tool;
202
203 // Redirect stdout and stderr to nowhere if SilencePasses is given
204 sys::Path Nowhere;
205 const sys::Path *Redirects[3] = {0, &Nowhere, &Nowhere};
206
207 int result = sys::Program::ExecuteAndWait(prog, Args.data(), 0,
208 (SilencePasses ? Redirects : 0),
209 Timeout, MemoryLimit, &ErrMsg);
210
211 // If we are supposed to delete the bitcode file or if the passes crashed,
212 // remove it now. This may fail if the file was never created, but that's ok.
213 if (DeleteOutput || result != 0)
214 sys::Path(OutputFilename).eraseFromDisk();
215
216 // Remove the temporary input file as well
217 inputFilename.eraseFromDisk();
218
219 if (!Quiet) {
220 if (result == 0)
221 outs() << "Success!\n";
222 else if (result > 0)
223 outs() << "Exited with error code '" << result << "'\n";
224 else if (result < 0) {
225 if (result == -1)
226 outs() << "Execute failed: " << ErrMsg << "\n";
227 else
228 outs() << "Crashed: " << ErrMsg << "\n";
229 }
230 if (result & 0x01000000)
231 outs() << "Dumped core\n";
232 }
233
234 // Was the child successful?
235 return result != 0;
236 }
237
238
239 /// runPassesOn - Carefully run the specified set of pass on the specified
240 /// module, returning the transformed module on success, or a null pointer on
241 /// failure.
runPassesOn(Module * M,const std::vector<std::string> & Passes,bool AutoDebugCrashes,unsigned NumExtraArgs,const char * const * ExtraArgs)242 Module *BugDriver::runPassesOn(Module *M,
243 const std::vector<std::string> &Passes,
244 bool AutoDebugCrashes, unsigned NumExtraArgs,
245 const char * const *ExtraArgs) {
246 std::string BitcodeResult;
247 if (runPasses(M, Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
248 NumExtraArgs, ExtraArgs)) {
249 if (AutoDebugCrashes) {
250 errs() << " Error running this sequence of passes"
251 << " on the input program!\n";
252 delete swapProgramIn(M);
253 EmitProgressBitcode(M, "pass-error", false);
254 exit(debugOptimizerCrash());
255 }
256 return 0;
257 }
258
259 Module *Ret = ParseInputFile(BitcodeResult, Context);
260 if (Ret == 0) {
261 errs() << getToolName() << ": Error reading bitcode file '"
262 << BitcodeResult << "'!\n";
263 exit(1);
264 }
265 sys::Path(BitcodeResult).eraseFromDisk(); // No longer need the file on disk
266 return Ret;
267 }
268