1 //===- bugpoint.cpp - The LLVM Bugpoint utility ---------------------------===//
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 program is an automated compiler debugger tool.  It is used to narrow
10 // down miscompilations and crash problems to a specific pass in the compiler,
11 // and the specific Module or Function input that is causing the problem.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "BugDriver.h"
16 #include "ToolRunner.h"
17 #include "llvm/Config/llvm-config.h"
18 #include "llvm/IR/LLVMContext.h"
19 #include "llvm/IR/LegacyPassManager.h"
20 #include "llvm/IR/LegacyPassNameParser.h"
21 #include "llvm/InitializePasses.h"
22 #include "llvm/LinkAllIR.h"
23 #include "llvm/LinkAllPasses.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/InitLLVM.h"
26 #include "llvm/Support/ManagedStatic.h"
27 #include "llvm/Support/PluginLoader.h"
28 #include "llvm/Support/PrettyStackTrace.h"
29 #include "llvm/Support/Process.h"
30 #include "llvm/Support/TargetSelect.h"
31 #include "llvm/Support/Valgrind.h"
32 #include "llvm/Transforms/IPO/AlwaysInliner.h"
33 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
34 
35 // Enable this macro to debug bugpoint itself.
36 //#define DEBUG_BUGPOINT 1
37 
38 using namespace llvm;
39 
40 static cl::opt<bool>
41     FindBugs("find-bugs", cl::desc("Run many different optimization sequences "
42                                    "on program to find bugs"),
43              cl::init(false));
44 
45 static cl::list<std::string>
46     InputFilenames(cl::Positional, cl::OneOrMore,
47                    cl::desc("<input llvm ll/bc files>"));
48 
49 static cl::opt<unsigned> TimeoutValue(
50     "timeout", cl::init(300), cl::value_desc("seconds"),
51     cl::desc("Number of seconds program is allowed to run before it "
52              "is killed (default is 300s), 0 disables timeout"));
53 
54 static cl::opt<int> MemoryLimit(
55     "mlimit", cl::init(-1), cl::value_desc("MBytes"),
56     cl::desc("Maximum amount of memory to use. 0 disables check. Defaults to "
57              "400MB (800MB under valgrind, 0 with sanitizers)."));
58 
59 static cl::opt<bool>
60     UseValgrind("enable-valgrind",
61                 cl::desc("Run optimizations through valgrind"));
62 
63 // The AnalysesList is automatically populated with registered Passes by the
64 // PassNameParser.
65 //
66 static cl::list<const PassInfo *, bool, PassNameParser>
67     PassList(cl::desc("Passes available:"), cl::ZeroOrMore);
68 
69 static cl::opt<bool>
70     StandardLinkOpts("std-link-opts",
71                      cl::desc("Include the standard link time optimizations"));
72 
73 static cl::opt<bool>
74     OptLevelO1("O1", cl::desc("Optimization level 1. Identical to 'opt -O1'"));
75 
76 static cl::opt<bool>
77     OptLevelO2("O2", cl::desc("Optimization level 2. Identical to 'opt -O2'"));
78 
79 static cl::opt<bool> OptLevelOs(
80     "Os",
81     cl::desc(
82         "Like -O2 with extra optimizations for size. Similar to clang -Os"));
83 
84 static cl::opt<bool>
85 OptLevelOz("Oz",
86            cl::desc("Like -Os but reduces code size further. Similar to clang -Oz"));
87 
88 static cl::opt<bool>
89     OptLevelO3("O3", cl::desc("Optimization level 3. Identical to 'opt -O3'"));
90 
91 static cl::opt<std::string>
92     OverrideTriple("mtriple", cl::desc("Override target triple for module"));
93 
94 /// BugpointIsInterrupted - Set to true when the user presses ctrl-c.
95 bool llvm::BugpointIsInterrupted = false;
96 
97 #ifndef DEBUG_BUGPOINT
98 static void BugpointInterruptFunction() { BugpointIsInterrupted = true; }
99 #endif
100 
101 // Hack to capture a pass list.
102 namespace {
103 class AddToDriver : public legacy::FunctionPassManager {
104   BugDriver &D;
105 
106 public:
107   AddToDriver(BugDriver &_D) : FunctionPassManager(nullptr), D(_D) {}
108 
109   void add(Pass *P) override {
110     const void *ID = P->getPassID();
111     const PassInfo *PI = PassRegistry::getPassRegistry()->getPassInfo(ID);
112     D.addPass(PI->getPassArgument());
113   }
114 };
115 }
116 
117 // This routine adds optimization passes based on selected optimization level,
118 // OptLevel.
119 //
120 // OptLevel - Optimization Level
121 static void AddOptimizationPasses(legacy::FunctionPassManager &FPM,
122                                   unsigned OptLevel,
123                                   unsigned SizeLevel) {
124   PassManagerBuilder Builder;
125   Builder.OptLevel = OptLevel;
126   Builder.SizeLevel = SizeLevel;
127 
128   if (OptLevel > 1)
129     Builder.Inliner = createFunctionInliningPass(OptLevel, SizeLevel, false);
130   else
131     Builder.Inliner = createAlwaysInlinerLegacyPass();
132 
133   Builder.populateFunctionPassManager(FPM);
134   Builder.populateModulePassManager(FPM);
135 }
136 
137 #ifdef LINK_POLLY_INTO_TOOLS
138 namespace polly {
139 void initializePollyPasses(llvm::PassRegistry &Registry);
140 }
141 #endif
142 
143 int main(int argc, char **argv) {
144 #ifndef DEBUG_BUGPOINT
145   InitLLVM X(argc, argv);
146 #endif
147 
148   // Initialize passes
149   PassRegistry &Registry = *PassRegistry::getPassRegistry();
150   initializeCore(Registry);
151   initializeScalarOpts(Registry);
152   initializeObjCARCOpts(Registry);
153   initializeVectorization(Registry);
154   initializeIPO(Registry);
155   initializeAnalysis(Registry);
156   initializeTransformUtils(Registry);
157   initializeInstCombine(Registry);
158   initializeAggressiveInstCombine(Registry);
159   initializeInstrumentation(Registry);
160   initializeTarget(Registry);
161 
162 #ifdef LINK_POLLY_INTO_TOOLS
163   polly::initializePollyPasses(Registry);
164 #endif
165 
166   if (std::getenv("bar") == (char*) -1) {
167     InitializeAllTargets();
168     InitializeAllTargetMCs();
169     InitializeAllAsmPrinters();
170     InitializeAllAsmParsers();
171   }
172 
173   cl::ParseCommandLineOptions(argc, argv,
174                               "LLVM automatic testcase reducer. See\nhttp://"
175                               "llvm.org/cmds/bugpoint.html"
176                               " for more information.\n");
177 #ifndef DEBUG_BUGPOINT
178   sys::SetInterruptFunction(BugpointInterruptFunction);
179 #endif
180 
181   LLVMContext Context;
182   // If we have an override, set it and then track the triple we want Modules
183   // to use.
184   if (!OverrideTriple.empty()) {
185     TargetTriple.setTriple(Triple::normalize(OverrideTriple));
186     outs() << "Override triple set to '" << TargetTriple.getTriple() << "'\n";
187   }
188 
189   if (MemoryLimit < 0) {
190     // Set the default MemoryLimit.  Be sure to update the flag's description if
191     // you change this.
192     if (sys::RunningOnValgrind() || UseValgrind)
193       MemoryLimit = 800;
194     else
195       MemoryLimit = 400;
196 #if (LLVM_ADDRESS_SANITIZER_BUILD || LLVM_MEMORY_SANITIZER_BUILD ||            \
197      LLVM_THREAD_SANITIZER_BUILD)
198     // Starting from kernel 4.9 memory allocated with mmap is counted against
199     // RLIMIT_DATA. Sanitizers need to allocate tens of terabytes for shadow.
200     MemoryLimit = 0;
201 #endif
202   }
203 
204   BugDriver D(argv[0], FindBugs, TimeoutValue, MemoryLimit, UseValgrind,
205               Context);
206   if (D.addSources(InputFilenames))
207     return 1;
208 
209   AddToDriver PM(D);
210 
211   if (StandardLinkOpts) {
212     PassManagerBuilder Builder;
213     Builder.Inliner = createFunctionInliningPass();
214     Builder.populateLTOPassManager(PM);
215   }
216 
217   if (OptLevelO1)
218     AddOptimizationPasses(PM, 1, 0);
219   else if (OptLevelO2)
220     AddOptimizationPasses(PM, 2, 0);
221   else if (OptLevelO3)
222     AddOptimizationPasses(PM, 3, 0);
223   else if (OptLevelOs)
224     AddOptimizationPasses(PM, 2, 1);
225   else if (OptLevelOz)
226     AddOptimizationPasses(PM, 2, 2);
227 
228   for (const PassInfo *PI : PassList)
229     D.addPass(PI->getPassArgument());
230 
231 // Bugpoint has the ability of generating a plethora of core files, so to
232 // avoid filling up the disk, we prevent it
233 #ifndef DEBUG_BUGPOINT
234   sys::Process::PreventCoreFiles();
235 #endif
236 
237   if (Error E = D.run()) {
238     errs() << toString(std::move(E));
239     return 1;
240   }
241   return 0;
242 }
243