1//===- BugDriver.cpp - Top-Level BugPoint class implementation ------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This class contains all of the shared state and information that is used by
10// the BugPoint tool to track down errors in optimizations.  This class is the
11// main driver class that invokes all sub-functionality.
12//
13//===----------------------------------------------------------------------===//
14
15#include "BugDriver.h"
16#include "ToolRunner.h"
17#include "llvm/IR/Module.h"
18#include "llvm/IR/Verifier.h"
19#include "llvm/IRReader/IRReader.h"
20#include "llvm/Linker/Linker.h"
21#include "llvm/Pass.h"
22#include "llvm/Support/CommandLine.h"
23#include "llvm/Support/FileUtilities.h"
24#include "llvm/Support/Host.h"
25#include "llvm/Support/SourceMgr.h"
26#include "llvm/Support/raw_ostream.h"
27#include <memory>
28using namespace llvm;
29
30namespace llvm {
31Triple TargetTriple;
32}
33
34DiscardTemp::~DiscardTemp() {
35  if (SaveTemps) {
36    if (Error E = File.keep())
37      errs() << "Failed to keep temp file " << toString(std::move(E)) << '\n';
38    return;
39  }
40  if (Error E = File.discard())
41    errs() << "Failed to delete temp file " << toString(std::move(E)) << '\n';
42}
43
44// Anonymous namespace to define command line options for debugging.
45//
46namespace {
47// Output - The user can specify a file containing the expected output of the
48// program.  If this filename is set, it is used as the reference diff source,
49// otherwise the raw input run through an interpreter is used as the reference
50// source.
51//
52cl::opt<std::string> OutputFile("output",
53                                cl::desc("Specify a reference program output "
54                                         "(for miscompilation detection)"));
55}
56
57/// If we reduce or update the program somehow, call this method to update
58/// bugdriver with it.  This deletes the old module and sets the specified one
59/// as the current program.
60void BugDriver::setNewProgram(std::unique_ptr<Module> M) {
61  Program = std::move(M);
62}
63
64/// getPassesString - Turn a list of passes into a string which indicates the
65/// command line options that must be passed to add the passes.
66///
67std::string llvm::getPassesString(const std::vector<std::string> &Passes) {
68  std::string Result;
69  for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
70    if (i)
71      Result += " ";
72    Result += "-";
73    Result += Passes[i];
74  }
75  return Result;
76}
77
78BugDriver::BugDriver(const char *toolname, bool find_bugs, unsigned timeout,
79                     unsigned memlimit, bool use_valgrind, LLVMContext &ctxt)
80    : Context(ctxt), ToolName(toolname), ReferenceOutputFile(OutputFile),
81      Program(nullptr), Interpreter(nullptr), SafeInterpreter(nullptr),
82      cc(nullptr), run_find_bugs(find_bugs), Timeout(timeout),
83      MemoryLimit(memlimit), UseValgrind(use_valgrind) {}
84
85BugDriver::~BugDriver() {
86  if (Interpreter != SafeInterpreter)
87    delete Interpreter;
88  delete SafeInterpreter;
89  delete cc;
90}
91
92std::unique_ptr<Module> llvm::parseInputFile(StringRef Filename,
93                                             LLVMContext &Ctxt) {
94  SMDiagnostic Err;
95  std::unique_ptr<Module> Result = parseIRFile(Filename, Err, Ctxt);
96  if (!Result) {
97    Err.print("bugpoint", errs());
98    return Result;
99  }
100
101  if (verifyModule(*Result, &errs())) {
102    errs() << "bugpoint: " << Filename << ": error: input module is broken!\n";
103    return std::unique_ptr<Module>();
104  }
105
106  // If we don't have an override triple, use the first one to configure
107  // bugpoint, or use the host triple if none provided.
108  if (TargetTriple.getTriple().empty()) {
109    Triple TheTriple(Result->getTargetTriple());
110
111    if (TheTriple.getTriple().empty())
112      TheTriple.setTriple(sys::getDefaultTargetTriple());
113
114    TargetTriple.setTriple(TheTriple.getTriple());
115  }
116
117  Result->setTargetTriple(TargetTriple.getTriple()); // override the triple
118  return Result;
119}
120
121std::unique_ptr<Module> BugDriver::swapProgramIn(std::unique_ptr<Module> M) {
122  std::unique_ptr<Module> OldProgram = std::move(Program);
123  Program = std::move(M);
124  return OldProgram;
125}
126
127// This method takes the specified list of LLVM input files, attempts to load
128// them, either as assembly or bitcode, then link them together. It returns
129// true on failure (if, for example, an input bitcode file could not be
130// parsed), and false on success.
131//
132bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
133  assert(!Program && "Cannot call addSources multiple times!");
134  assert(!Filenames.empty() && "Must specify at least on input filename!");
135
136  // Load the first input file.
137  Program = parseInputFile(Filenames[0], Context);
138  if (!Program)
139    return true;
140
141  outs() << "Read input file      : '" << Filenames[0] << "'\n";
142
143  for (unsigned i = 1, e = Filenames.size(); i != e; ++i) {
144    std::unique_ptr<Module> M = parseInputFile(Filenames[i], Context);
145    if (!M.get())
146      return true;
147
148    outs() << "Linking in input file: '" << Filenames[i] << "'\n";
149    if (Linker::linkModules(*Program, std::move(M)))
150      return true;
151  }
152
153  outs() << "*** All input ok\n";
154
155  // All input files read successfully!
156  return false;
157}
158
159/// run - The top level method that is invoked after all of the instance
160/// variables are set up from command line arguments.
161///
162Error BugDriver::run() {
163  if (run_find_bugs) {
164    // Rearrange the passes and apply them to the program. Repeat this process
165    // until the user kills the program or we find a bug.
166    return runManyPasses(PassesToRun);
167  }
168
169  // If we're not running as a child, the first thing that we must do is
170  // determine what the problem is. Does the optimization series crash the
171  // compiler, or does it produce illegal code?  We make the top-level
172  // decision by trying to run all of the passes on the input program,
173  // which should generate a bitcode file.  If it does generate a bitcode
174  // file, then we know the compiler didn't crash, so try to diagnose a
175  // miscompilation.
176  if (!PassesToRun.empty()) {
177    outs() << "Running selected passes on program to test for crash: ";
178    if (runPasses(*Program, PassesToRun))
179      return debugOptimizerCrash();
180  }
181
182  // Set up the execution environment, selecting a method to run LLVM bitcode.
183  if (Error E = initializeExecutionEnvironment())
184    return E;
185
186  // Test to see if we have a code generator crash.
187  outs() << "Running the code generator to test for a crash: ";
188  if (Error E = compileProgram(*Program)) {
189    outs() << toString(std::move(E));
190    return debugCodeGeneratorCrash();
191  }
192  outs() << '\n';
193
194  // Run the raw input to see where we are coming from.  If a reference output
195  // was specified, make sure that the raw output matches it.  If not, it's a
196  // problem in the front-end or the code generator.
197  //
198  bool CreatedOutput = false;
199  if (ReferenceOutputFile.empty()) {
200    outs() << "Generating reference output from raw program: ";
201    if (Error E = createReferenceFile(*Program)) {
202      errs() << toString(std::move(E));
203      return debugCodeGeneratorCrash();
204    }
205    CreatedOutput = true;
206  }
207
208  // Make sure the reference output file gets deleted on exit from this
209  // function, if appropriate.
210  std::string ROF(ReferenceOutputFile);
211  FileRemover RemoverInstance(ROF, CreatedOutput && !SaveTemps);
212
213  // Diff the output of the raw program against the reference output.  If it
214  // matches, then we assume there is a miscompilation bug and try to
215  // diagnose it.
216  outs() << "*** Checking the code generator...\n";
217  Expected<bool> Diff = diffProgram(*Program, "", "", false);
218  if (Error E = Diff.takeError()) {
219    errs() << toString(std::move(E));
220    return debugCodeGeneratorCrash();
221  }
222  if (!*Diff) {
223    outs() << "\n*** Output matches: Debugging miscompilation!\n";
224    if (Error E = debugMiscompilation()) {
225      errs() << toString(std::move(E));
226      return debugCodeGeneratorCrash();
227    }
228    return Error::success();
229  }
230
231  outs() << "\n*** Input program does not match reference diff!\n";
232  outs() << "Debugging code generator problem!\n";
233  if (Error E = debugCodeGenerator()) {
234    errs() << toString(std::move(E));
235    return debugCodeGeneratorCrash();
236  }
237  return Error::success();
238}
239
240void llvm::PrintFunctionList(const std::vector<Function *> &Funcs) {
241  unsigned NumPrint = Funcs.size();
242  if (NumPrint > 10)
243    NumPrint = 10;
244  for (unsigned i = 0; i != NumPrint; ++i)
245    outs() << " " << Funcs[i]->getName();
246  if (NumPrint < Funcs.size())
247    outs() << "... <" << Funcs.size() << " total>";
248  outs().flush();
249}
250
251void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable *> &GVs) {
252  unsigned NumPrint = GVs.size();
253  if (NumPrint > 10)
254    NumPrint = 10;
255  for (unsigned i = 0; i != NumPrint; ++i)
256    outs() << " " << GVs[i]->getName();
257  if (NumPrint < GVs.size())
258    outs() << "... <" << GVs.size() << " total>";
259  outs().flush();
260}
261