llvm-6502/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.h
Mehdi Amini c94da20917 Make DataLayout Non-Optional in the Module
Summary:
DataLayout keeps the string used for its creation.

As a side effect it is no longer needed in the Module.
This is "almost" NFC, the string is no longer
canonicalized, you can't rely on two "equals" DataLayout
having the same string returned by getStringRepresentation().

Get rid of DataLayoutPass: the DataLayout is in the Module

The DataLayout is "per-module", let's enforce this by not
duplicating it more than necessary.
One more step toward non-optionality of the DataLayout in the
module.

Make DataLayout Non-Optional in the Module

Module->getDataLayout() will never returns nullptr anymore.

Reviewers: echristo

Subscribers: resistor, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D7992

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231270 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-04 18:43:29 +00:00

73 lines
2.9 KiB
C++

//===- ObjCARCAliasAnalysis.h - ObjC ARC Optimization -*- C++ -*-----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
/// \file
/// This file declares a simple ARC-aware AliasAnalysis using special knowledge
/// of Objective C to enhance other optimization passes which rely on the Alias
/// Analysis infrastructure.
///
/// WARNING: This file knows about certain library functions. It recognizes them
/// by name, and hardwires knowledge of their semantics.
///
/// WARNING: This file knows about how certain Objective-C library functions are
/// used. Naive LLVM IR transformations which would otherwise be
/// behavior-preserving may break these assumptions.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TRANSFORMS_OBJCARC_OBJCARCALIASANALYSIS_H
#define LLVM_LIB_TRANSFORMS_OBJCARC_OBJCARCALIASANALYSIS_H
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Pass.h"
namespace llvm {
namespace objcarc {
/// \brief This is a simple alias analysis implementation that uses knowledge
/// of ARC constructs to answer queries.
///
/// TODO: This class could be generalized to know about other ObjC-specific
/// tricks. Such as knowing that ivars in the non-fragile ABI are non-aliasing
/// even though their offsets are dynamic.
class ObjCARCAliasAnalysis : public ImmutablePass,
public AliasAnalysis {
public:
static char ID; // Class identification, replacement for typeinfo
ObjCARCAliasAnalysis() : ImmutablePass(ID) {
initializeObjCARCAliasAnalysisPass(*PassRegistry::getPassRegistry());
}
private:
bool doInitialization(Module &M) override;
/// This method is used when a pass implements an analysis interface through
/// multiple inheritance. If needed, it should override this to adjust the
/// this pointer as needed for the specified pass info.
void *getAdjustedAnalysisPointer(const void *PI) override {
if (PI == &AliasAnalysis::ID)
return static_cast<AliasAnalysis *>(this);
return this;
}
void getAnalysisUsage(AnalysisUsage &AU) const override;
AliasResult alias(const Location &LocA, const Location &LocB) override;
bool pointsToConstantMemory(const Location &Loc, bool OrLocal) override;
ModRefBehavior getModRefBehavior(ImmutableCallSite CS) override;
ModRefBehavior getModRefBehavior(const Function *F) override;
ModRefResult getModRefInfo(ImmutableCallSite CS,
const Location &Loc) override;
ModRefResult getModRefInfo(ImmutableCallSite CS1,
ImmutableCallSite CS2) override;
};
} // namespace objcarc
} // namespace llvm
#endif