From ffe695c29915cf8605b2fb807cd083cdcc769d47 Mon Sep 17 00:00:00 2001 From: Dan Liew Date: Tue, 18 Jul 2017 16:04:19 +0100 Subject: Replace assertions of types on LLVM instructions in the Executor with a pass that checks these assertions. This improves several things. * This pass provides more friendly messages than assertions in that it just emits a warning and carries on checking the rest of the instructions. * The takes the checks outside of the Executor's hot path and so avoids checking the same instruction multiple times. Now each instruction is only checked once just before execution starts. The disadvantage of this approach is the check for invariants we expect to hold have been pulled far away from where we expect them to hold. After discussion with @ccadar and @MartinNowack it was decided we will take this hit to readability for better performance and simpler code in the Executor. --- lib/Module/InstructionOperandTypeCheckPass.cpp | 184 +++++++++++++++++++++++++ 1 file changed, 184 insertions(+) create mode 100644 lib/Module/InstructionOperandTypeCheckPass.cpp (limited to 'lib/Module/InstructionOperandTypeCheckPass.cpp') diff --git a/lib/Module/InstructionOperandTypeCheckPass.cpp b/lib/Module/InstructionOperandTypeCheckPass.cpp new file mode 100644 index 00000000..449eea48 --- /dev/null +++ b/lib/Module/InstructionOperandTypeCheckPass.cpp @@ -0,0 +1,184 @@ +//===-- InstructionOperandTypeCheckPass.cpp ---------------------*- C++ -*-===// +// +// The KLEE Symbolic Virtual Machine +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +#include "Passes.h" +#include "klee/Config/Version.h" +#include "klee/Internal/Support/ErrorHandling.h" +#include "llvm/Support/raw_ostream.h" + +using namespace llvm; + +namespace { + +void printOperandWarning(const char *expected, const Instruction *i, + LLVM_TYPE_Q Type *ty, unsigned opNum) { + std::string msg; + llvm::raw_string_ostream ss(msg); + ss << "Found unexpected type (" << *ty << ") at operand " << opNum + << ". Expected " << expected << " in " << *i; + i->print(ss); + ss.flush(); + klee::klee_warning("%s", msg.c_str()); +} + +bool checkOperandTypeIsScalarInt(const Instruction *i, unsigned opNum) { + assert(opNum < i->getNumOperands()); + LLVM_TYPE_Q llvm::Type *ty = i->getOperand(opNum)->getType(); + if (!(ty->isIntegerTy())) { + printOperandWarning("scalar integer", i, ty, opNum); + return false; + } + return true; +} + +bool checkOperandTypeIsScalarIntOrPointer(const Instruction *i, + unsigned opNum) { + assert(opNum < i->getNumOperands()); + LLVM_TYPE_Q llvm::Type *ty = i->getOperand(opNum)->getType(); + if (!(ty->isIntegerTy() || ty->isPointerTy())) { + printOperandWarning("scalar integer or pointer", i, ty, opNum); + return false; + } + return true; +} + +bool checkOperandTypeIsScalarPointer(const Instruction *i, unsigned opNum) { + assert(opNum < i->getNumOperands()); + LLVM_TYPE_Q llvm::Type *ty = i->getOperand(opNum)->getType(); + if (!(ty->isPointerTy())) { + printOperandWarning("scalar pointer", i, ty, opNum); + return false; + } + return true; +} + +bool checkOperandTypeIsScalarFloat(const Instruction *i, unsigned opNum) { + assert(opNum < i->getNumOperands()); + LLVM_TYPE_Q llvm::Type *ty = i->getOperand(opNum)->getType(); + if (!(ty->isFloatingPointTy())) { + printOperandWarning("scalar float", i, ty, opNum); + return false; + } + return true; +} + +bool checkOperandsHaveSameType(const Instruction *i, unsigned opNum0, + unsigned opNum1) { + assert(opNum0 < i->getNumOperands()); + assert(opNum1 < i->getNumOperands()); + LLVM_TYPE_Q llvm::Type *ty0 = i->getOperand(opNum0)->getType(); + LLVM_TYPE_Q llvm::Type *ty1 = i->getOperand(opNum1)->getType(); + if (!(ty0 == ty1)) { + std::string msg; + llvm::raw_string_ostream ss(msg); + ss << "Found mismatched type (" << *ty0 << " != " << *ty1 + << ") for operands" << opNum0 << " and " << opNum1 + << ". Expected operand types to match in " << *i; + i->print(ss); + ss.flush(); + klee::klee_warning("%s", msg.c_str()); + return false; + } + return true; +} + +bool checkInstruction(const Instruction *i) { + switch (i->getOpcode()) { + case Instruction::Select: { + // Note we do not enforce that operand 1 and 2 are scalar because the + // scalarizer pass might not remove these. This could be selecting which + // vector operand to feed to another instruction. The Executor can handle + // this so case so this is not a problem + return checkOperandTypeIsScalarInt(i, 0) & + checkOperandsHaveSameType(i, 1, 2); + } + // Integer arithmetic, logical and shifting + // TODO: When we upgrade to newer LLVM use LLVM_FALLTHROUGH + case Instruction::Add: + case Instruction::Sub: + case Instruction::Mul: + case Instruction::UDiv: + case Instruction::SDiv: + case Instruction::URem: + case Instruction::SRem: + case Instruction::And: + case Instruction::Or: + case Instruction::Xor: + case Instruction::Shl: + case Instruction::LShr: + case Instruction::AShr: { + return checkOperandTypeIsScalarInt(i, 0) & + checkOperandTypeIsScalarInt(i, 1); + } + // Integer comparison + case Instruction::ICmp: { + return checkOperandTypeIsScalarIntOrPointer(i, 0) & + checkOperandTypeIsScalarIntOrPointer(i, 1); + } + // Integer Conversion + case Instruction::Trunc: + case Instruction::ZExt: + case Instruction::SExt: + case Instruction::IntToPtr: { + return checkOperandTypeIsScalarInt(i, 0); + } + case Instruction::PtrToInt: { + return checkOperandTypeIsScalarPointer(i, 0); + } + // TODO: Figure out if Instruction::BitCast needs checking + // Floating point arithmetic + case Instruction::FAdd: + case Instruction::FSub: + case Instruction::FMul: + case Instruction::FDiv: + case Instruction::FRem: { + return checkOperandTypeIsScalarFloat(i, 0) & + checkOperandTypeIsScalarFloat(i, 1); + } + // Floating point conversion + case Instruction::FPTrunc: + case Instruction::FPExt: + case Instruction::FPToUI: + case Instruction::FPToSI: { + return checkOperandTypeIsScalarFloat(i, 0); + } + case Instruction::UIToFP: + case Instruction::SIToFP: { + return checkOperandTypeIsScalarInt(i, 0); + } + // Floating point comparison + case Instruction::FCmp: { + return checkOperandTypeIsScalarFloat(i, 0) & + checkOperandTypeIsScalarFloat(i, 1); + } + default: + // Treat all other instructions as conforming + return true; + } +} +} + +namespace klee { + +char InstructionOperandTypeCheckPass::ID = 0; + +bool InstructionOperandTypeCheckPass::runOnModule(Module &M) { + instructionOperandsConform = true; + for (Module::iterator fi = M.begin(), fe = M.end(); fi != fe; ++fi) { + for (Function::iterator bi = fi->begin(), be = fi->end(); bi != be; ++bi) { + for (BasicBlock::iterator ii = bi->begin(), ie = bi->end(); ii != ie; + ++ii) { + Instruction *i = static_cast(ii); + instructionOperandsConform &= checkInstruction(i); + } + } + } + + return false; +} +} -- cgit 1.4.1