llvm/lib/IR/IntrinsicInst.cpp
Duncan P. N. Exon Smith 0ee5788656 IR: Add DbgInfoIntrinsic::getVariableLocation
Create a common accessor, DbgInfoIntrinsic::getVariableLocation, which
doesn't care about the type of debug info intrinsic.  Use this to
further unify the implementations of DbgDeclareInst::getAddress and
DbgValueInst::getValue.

Besides being a cleanup, I'm planning to use this to prepare DEBUG
output without having to branch on the concrete type.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264767 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-29 18:56:03 +00:00

104 lines
3.8 KiB
C++

//===-- InstrinsicInst.cpp - Intrinsic Instruction Wrappers ---------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements methods that make it really easy to deal with intrinsic
// functions.
//
// All intrinsic function calls are instances of the call instruction, so these
// are all subclasses of the CallInst class. Note that none of these classes
// has state or virtual methods, which is an important part of this gross/neat
// hack working.
//
// In some cases, arguments to intrinsics need to be generic and are defined as
// type pointer to empty struct { }*. To access the real item of interest the
// cast instruction needs to be stripped away.
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Metadata.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
/// DbgInfoIntrinsic - This is the common base class for debug info intrinsics
///
static Value *CastOperand(Value *C) {
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
if (CE->isCast())
return CE->getOperand(0);
return nullptr;
}
Value *DbgInfoIntrinsic::StripCast(Value *C) {
if (Value *CO = CastOperand(C)) {
C = StripCast(CO);
} else if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) {
if (GV->hasInitializer())
if (Value *CO = CastOperand(GV->getInitializer()))
C = StripCast(CO);
}
return dyn_cast<GlobalVariable>(C);
}
Value *DbgInfoIntrinsic::getVariableLocation(bool AllowNullOp) const {
Value *Op = getArgOperand(0);
if (AllowNullOp && !Op)
return nullptr;
auto *MD = cast<MetadataAsValue>(Op)->getMetadata();
if (auto *V = dyn_cast<ValueAsMetadata>(MD))
return V->getValue();
// When the value goes to null, it gets replaced by an empty MDNode.
assert(!cast<MDNode>(MD)->getNumOperands() && "Expected an empty MDNode");
return nullptr;
}
int llvm::Intrinsic::lookupLLVMIntrinsicByName(ArrayRef<const char *> NameTable,
StringRef Name) {
assert(Name.startswith("llvm."));
// Do successive binary searches of the dotted name components. For
// "llvm.gc.experimental.statepoint.p1i8.p1i32", we will find the range of
// intrinsics starting with "llvm.gc", then "llvm.gc.experimental", then
// "llvm.gc.experimental.statepoint", and then we will stop as the range is
// size 1. During the search, we can skip the prefix that we already know is
// identical. By using strncmp we consider names with differing suffixes to
// be part of the equal range.
size_t CmpStart = 0;
size_t CmpEnd = 4; // Skip the "llvm" component.
const char *const *Low = NameTable.begin();
const char *const *High = NameTable.end();
const char *const *LastLow = Low;
while (CmpEnd < Name.size() && High - Low > 0) {
CmpStart = CmpEnd;
CmpEnd = Name.find('.', CmpStart + 1);
CmpEnd = CmpEnd == StringRef::npos ? Name.size() : CmpEnd;
auto Cmp = [CmpStart, CmpEnd](const char *LHS, const char *RHS) {
return strncmp(LHS + CmpStart, RHS + CmpStart, CmpEnd - CmpStart) < 0;
};
LastLow = Low;
std::tie(Low, High) = std::equal_range(Low, High, Name.data(), Cmp);
}
if (High - Low > 0)
LastLow = Low;
if (LastLow == NameTable.end())
return -1;
StringRef NameFound = *LastLow;
if (Name == NameFound ||
(Name.startswith(NameFound) && Name[NameFound.size()] == '.'))
return LastLow - NameTable.begin();
return -1;
}