TestPasses.cpp

//===- TestPasses.cpp - "buggy" passes used to test bugpoint --------------===//
//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains "buggy" passes that are used to test bugpoint, to check
// that it is narrowing down testcases correctly.
//
//===----------------------------------------------------------------------===//

#include"llvm/IR/BasicBlock.h"
#include"llvm/IR/Constant.h"
#include"llvm/IR/InstIterator.h"
#include"llvm/IR/InstVisitor.h"
#include"llvm/IR/Instructions.h"
#include"llvm/IR/Type.h"
#include"llvm/Pass.h"

#include"llvm/IR/PatternMatch.h"
usingnamespacellvm::PatternMatch;
usingnamespacellvm;

namespace {
/// CrashOnCalls - This pass is used to test bugpoint. It intentionally
/// crashes on any call instructions.
classCrashOnCalls : publicFunctionPass {
public:
staticchar ID; // Pass ID, replacement for typeid
CrashOnCalls() : FunctionPass(ID) {}

private:
voidgetAnalysisUsage(AnalysisUsage &AU) constoverride {
 AU.setPreservesAll();
 }

boolrunOnFunction(Function &F) override {
for (auto &BB : F)
for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I)
if (isa<CallInst>(*I))
abort();

returnfalse;
 }
};
}

char CrashOnCalls::ID = 0;
static RegisterPass<CrashOnCalls>
X("bugpoint-crashcalls",
"BugPoint Test Pass - Intentionally crash on CallInsts");

namespace {
/// DeleteCalls - This pass is used to test bugpoint. It intentionally
/// deletes some call instructions, "misoptimizing" the program.
classDeleteCalls : publicFunctionPass {
public:
staticchar ID; // Pass ID, replacement for typeid
DeleteCalls() : FunctionPass(ID) {}

private:
boolrunOnFunction(Function &F) override {
for (auto &BB : F)
for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I)
if (CallInst *CI = dyn_cast<CallInst>(I)) {
if (!CI->use_empty())
 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
 CI->getParent()->getInstList().erase(CI);
break;
 }
returnfalse;
 }
};
}

char DeleteCalls::ID = 0;
static RegisterPass<DeleteCalls>
Y("bugpoint-deletecalls",
"BugPoint Test Pass - Intentionally 'misoptimize' CallInsts");

namespace {
/// CrashOnDeclFunc - This pass is used to test bugpoint. It intentionally
/// crashes if the module has an undefined function (ie a function that is
/// defined in an external module).
classCrashOnDeclFunc : publicModulePass {
public:
staticchar ID; // Pass ID, replacement for typeid
CrashOnDeclFunc() : ModulePass(ID) {}

private:
boolrunOnModule(Module &M) override {
for (auto &F : M.functions()) {
if (F.isDeclaration())
abort();
 }
returnfalse;
 }
 };
}

char CrashOnDeclFunc::ID = 0;
static RegisterPass<CrashOnDeclFunc>
Z("bugpoint-crash-decl-funcs",
"BugPoint Test Pass - Intentionally crash on declared functions");

namespace {
/// CrashOnOneCU - This pass is used to test bugpoint. It intentionally
/// crashes if the Module has two or more compile units
classCrashOnTooManyCUs : publicModulePass {
public:
staticchar ID;
CrashOnTooManyCUs() : ModulePass(ID) {}

private:
boolrunOnModule(Module &M) override {
 NamedMDNode *CU_Nodes = M.getNamedMetadata("llvm.dbg.cu");
if (!CU_Nodes)
returnfalse;
if (CU_Nodes->getNumOperands() >= 2)
abort();
returnfalse;
 }
};
}

char CrashOnTooManyCUs::ID = 0;
static RegisterPass<CrashOnTooManyCUs>
A("bugpoint-crash-too-many-cus",
"BugPoint Test Pass - Intentionally crash on too many CUs");

namespace {
classCrashOnFunctionAttribute : publicFunctionPass {
public:
staticchar ID; // Pass ID, replacement for typeid
CrashOnFunctionAttribute() : FunctionPass(ID) {}

private:
voidgetAnalysisUsage(AnalysisUsage &AU) constoverride {
 AU.setPreservesAll();
 }

boolrunOnFunction(Function &F) override {
 AttributeSet A = F.getAttributes().getFnAttrs();
if (A.hasAttribute("bugpoint-crash"))
abort();
returnfalse;
 }
};
} // namespace

char CrashOnFunctionAttribute::ID = 0;
static RegisterPass<CrashOnFunctionAttribute>
B("bugpoint-crashfuncattr", "BugPoint Test Pass - Intentionally crash on "
"function attribute 'bugpoint-crash'");

namespace {
classCrashOnMetadata : publicFunctionPass {
public:
staticchar ID; // Pass ID, replacement for typeid
CrashOnMetadata() : FunctionPass(ID) {}

private:
voidgetAnalysisUsage(AnalysisUsage &AU) constoverride {
 AU.setPreservesAll();
 }

// Crash on fabs calls with fpmath metdata and an fadd as argument. This
// ensures the fadd instruction sticks around and we can check that the
// metadata there is dropped correctly.
boolrunOnFunction(Function &F) override {
for (Instruction &I : instructions(F))
if (match(&I, m_FAbs(m_FAdd(m_Value(), m_Value()))) &&
 I.hasMetadata("fpmath"))
abort();
returnfalse;
 }
};
} // namespace

char CrashOnMetadata::ID = 0;
static RegisterPass<CrashOnMetadata>
C("bugpoint-crashmetadata",
"BugPoint Test Pass - Intentionally crash on "
"fabs calls with fpmath metadata and an fadd as argument");