llvm-6502/lib/Transforms/ObjCARC/ProvenanceAnalysis.h
Mehdi Amini 529919ff31 DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231740 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 02:37:25 +00:00

82 lines
2.6 KiB
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//===- ProvenanceAnalysis.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 special form of Alias Analysis called ``Provenance
/// Analysis''. The word ``provenance'' refers to the history of the ownership
/// of an object. Thus ``Provenance Analysis'' is an analysis which attempts to
/// use various techniques to determine if locally
///
/// 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_PROVENANCEANALYSIS_H
#define LLVM_LIB_TRANSFORMS_OBJCARC_PROVENANCEANALYSIS_H
#include "llvm/ADT/DenseMap.h"
namespace llvm {
class Value;
class AliasAnalysis;
class DataLayout;
class PHINode;
class SelectInst;
}
namespace llvm {
namespace objcarc {
/// \brief This is similar to BasicAliasAnalysis, and it uses many of the same
/// techniques, except it uses special ObjC-specific reasoning about pointer
/// relationships.
///
/// In this context ``Provenance'' is defined as the history of an object's
/// ownership. Thus ``Provenance Analysis'' is defined by using the notion of
/// an ``independent provenance source'' of a pointer to determine whether or
/// not two pointers have the same provenance source and thus could
/// potentially be related.
class ProvenanceAnalysis {
AliasAnalysis *AA;
typedef std::pair<const Value *, const Value *> ValuePairTy;
typedef DenseMap<ValuePairTy, bool> CachedResultsTy;
CachedResultsTy CachedResults;
bool relatedCheck(const Value *A, const Value *B, const DataLayout &DL);
bool relatedSelect(const SelectInst *A, const Value *B);
bool relatedPHI(const PHINode *A, const Value *B);
void operator=(const ProvenanceAnalysis &) = delete;
ProvenanceAnalysis(const ProvenanceAnalysis &) = delete;
public:
ProvenanceAnalysis() {}
void setAA(AliasAnalysis *aa) { AA = aa; }
AliasAnalysis *getAA() const { return AA; }
bool related(const Value *A, const Value *B, const DataLayout &DL);
void clear() {
CachedResults.clear();
}
};
} // end namespace objcarc
} // end namespace llvm
#endif