src/llvm/tools/bugpoint-passes/TestPasses.cpp

   1 //===- TestPasses.cpp - "buggy" passes used to test bugpoint --------------===//
   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 contains "buggy" passes that are used to test bugpoint, to check
  11 // that it is narrowing down testcases correctly.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/IR/BasicBlock.h"
  16 #include "llvm/IR/Constant.h"
  17 #include "llvm/IR/InstVisitor.h"
  18 #include "llvm/IR/Instructions.h"
  19 #include "llvm/IR/Type.h"
  20 #include "llvm/Pass.h"
  21
  22 using namespace llvm;
  23
  24 namespace {
  25   /// CrashOnCalls - This pass is used to test bugpoint.  It intentionally
  26   /// crashes on any call instructions.
  27   class CrashOnCalls : public BasicBlockPass {
  28   public:
  29     static char ID; // Pass ID, replacement for typeid
  30     CrashOnCalls() : BasicBlockPass(ID) {}
  31   private:
  32     void getAnalysisUsage(AnalysisUsage &AU) const override {
  33       AU.setPreservesAll();
  34     }
  35
  36     bool runOnBasicBlock(BasicBlock &BB) override {
  37       for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I)
  38         if (isa<CallInst>(*I))
  39           abort();
  40
  41       return false;
  42     }
  43   };
  44 }
  45
  46 char CrashOnCalls::ID = 0;
  47 static RegisterPass<CrashOnCalls>
  48   X("bugpoint-crashcalls",
  49     "BugPoint Test Pass - Intentionally crash on CallInsts");
  50
  51 namespace {
  52   /// DeleteCalls - This pass is used to test bugpoint.  It intentionally
  53   /// deletes some call instructions, "misoptimizing" the program.
  54   class DeleteCalls : public BasicBlockPass {
  55   public:
  56     static char ID; // Pass ID, replacement for typeid
  57     DeleteCalls() : BasicBlockPass(ID) {}
  58   private:
  59     bool runOnBasicBlock(BasicBlock &BB) override {
  60       for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I)
  61         if (CallInst *CI = dyn_cast<CallInst>(I)) {
  62           if (!CI->use_empty())
  63             CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
  64           CI->getParent()->getInstList().erase(CI);
  65           break;
  66         }
  67       return false;
  68     }
  69   };
  70 }
  71
  72 char DeleteCalls::ID = 0;
  73 static RegisterPass<DeleteCalls>
  74   Y("bugpoint-deletecalls",
  75     "BugPoint Test Pass - Intentionally 'misoptimize' CallInsts");