[ptr-traits] Merge the MetadataTracking helpers into the Metadata

header.

This is part of a series of patches to allow LLVM to check for complete
pointee types when computing its pointer traits. This is absolutely
necessary to get correct (or reproducible) results for things like how
many low bits are guaranteed to be zero.

The MetadataTracking helpers aren't actually independent. They rely on
constructing a PointerUnion between Metadata and MetadataAsValue
pointers, which requires know the alignment of pointers to those types
which requires them to be complete.

The .cpp file even defined a method declared in Metadata.h! These really
don't seem like something that is separable, and there is no real
layering problem with just placing them together.

llvm-svn: 256531
This commit is contained in:
Chandler Carruth 2015-12-29 02:14:50 +00:00
parent dc82f13080
commit a7dc087b36
6 changed files with 112 additions and 161 deletions

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@ -18,10 +18,11 @@
#include "llvm/ADT/ArrayRef.h" #include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h" #include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/ADT/ilist_node.h" #include "llvm/ADT/ilist_node.h"
#include "llvm/ADT/iterator_range.h" #include "llvm/ADT/iterator_range.h"
#include "llvm/IR/Constant.h" #include "llvm/IR/Constant.h"
#include "llvm/IR/MetadataTracking.h" #include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Value.h" #include "llvm/IR/Value.h"
#include "llvm/Support/ErrorHandling.h" #include "llvm/Support/ErrorHandling.h"
#include <type_traits> #include <type_traits>
@ -196,6 +197,77 @@ private:
void untrack(); void untrack();
}; };
/// \brief API for tracking metadata references through RAUW and deletion.
///
/// Shared API for updating \a Metadata pointers in subclasses that support
/// RAUW.
///
/// This API is not meant to be used directly. See \a TrackingMDRef for a
/// user-friendly tracking reference.
class MetadataTracking {
public:
/// \brief Track the reference to metadata.
///
/// Register \c MD with \c *MD, if the subclass supports tracking. If \c *MD
/// gets RAUW'ed, \c MD will be updated to the new address. If \c *MD gets
/// deleted, \c MD will be set to \c nullptr.
///
/// If tracking isn't supported, \c *MD will not change.
///
/// \return true iff tracking is supported by \c MD.
static bool track(Metadata *&MD) {
return track(&MD, *MD, static_cast<Metadata *>(nullptr));
}
/// \brief Track the reference to metadata for \a Metadata.
///
/// As \a track(Metadata*&), but with support for calling back to \c Owner to
/// tell it that its operand changed. This could trigger \c Owner being
/// re-uniqued.
static bool track(void *Ref, Metadata &MD, Metadata &Owner) {
return track(Ref, MD, &Owner);
}
/// \brief Track the reference to metadata for \a MetadataAsValue.
///
/// As \a track(Metadata*&), but with support for calling back to \c Owner to
/// tell it that its operand changed. This could trigger \c Owner being
/// re-uniqued.
static bool track(void *Ref, Metadata &MD, MetadataAsValue &Owner) {
return track(Ref, MD, &Owner);
}
/// \brief Stop tracking a reference to metadata.
///
/// Stops \c *MD from tracking \c MD.
static void untrack(Metadata *&MD) { untrack(&MD, *MD); }
static void untrack(void *Ref, Metadata &MD);
/// \brief Move tracking from one reference to another.
///
/// Semantically equivalent to \c untrack(MD) followed by \c track(New),
/// except that ownership callbacks are maintained.
///
/// Note: it is an error if \c *MD does not equal \c New.
///
/// \return true iff tracking is supported by \c MD.
static bool retrack(Metadata *&MD, Metadata *&New) {
return retrack(&MD, *MD, &New);
}
static bool retrack(void *Ref, Metadata &MD, void *New);
/// \brief Check whether metadata is replaceable.
static bool isReplaceable(const Metadata &MD);
typedef PointerUnion<MetadataAsValue *, Metadata *> OwnerTy;
private:
/// \brief Track a reference to metadata for an owner.
///
/// Generalized version of tracking.
static bool track(void *Ref, Metadata &MD, OwnerTy Owner);
};
/// \brief Shared implementation of use-lists for replaceable metadata. /// \brief Shared implementation of use-lists for replaceable metadata.
/// ///
/// Most metadata cannot be RAUW'ed. This is a shared implementation of /// Most metadata cannot be RAUW'ed. This is a shared implementation of

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@ -1,99 +0,0 @@
//===- llvm/IR/MetadataTracking.h - Metadata tracking ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Low-level functions to enable tracking of metadata that could RAUW.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_METADATATRACKING_H
#define LLVM_IR_METADATATRACKING_H
#include "llvm/ADT/PointerUnion.h"
#include "llvm/Support/Casting.h"
#include <type_traits>
namespace llvm {
class Metadata;
class MetadataAsValue;
/// \brief API for tracking metadata references through RAUW and deletion.
///
/// Shared API for updating \a Metadata pointers in subclasses that support
/// RAUW.
///
/// This API is not meant to be used directly. See \a TrackingMDRef for a
/// user-friendly tracking reference.
class MetadataTracking {
public:
/// \brief Track the reference to metadata.
///
/// Register \c MD with \c *MD, if the subclass supports tracking. If \c *MD
/// gets RAUW'ed, \c MD will be updated to the new address. If \c *MD gets
/// deleted, \c MD will be set to \c nullptr.
///
/// If tracking isn't supported, \c *MD will not change.
///
/// \return true iff tracking is supported by \c MD.
static bool track(Metadata *&MD) {
return track(&MD, *MD, static_cast<Metadata *>(nullptr));
}
/// \brief Track the reference to metadata for \a Metadata.
///
/// As \a track(Metadata*&), but with support for calling back to \c Owner to
/// tell it that its operand changed. This could trigger \c Owner being
/// re-uniqued.
static bool track(void *Ref, Metadata &MD, Metadata &Owner) {
return track(Ref, MD, &Owner);
}
/// \brief Track the reference to metadata for \a MetadataAsValue.
///
/// As \a track(Metadata*&), but with support for calling back to \c Owner to
/// tell it that its operand changed. This could trigger \c Owner being
/// re-uniqued.
static bool track(void *Ref, Metadata &MD, MetadataAsValue &Owner) {
return track(Ref, MD, &Owner);
}
/// \brief Stop tracking a reference to metadata.
///
/// Stops \c *MD from tracking \c MD.
static void untrack(Metadata *&MD) { untrack(&MD, *MD); }
static void untrack(void *Ref, Metadata &MD);
/// \brief Move tracking from one reference to another.
///
/// Semantically equivalent to \c untrack(MD) followed by \c track(New),
/// except that ownership callbacks are maintained.
///
/// Note: it is an error if \c *MD does not equal \c New.
///
/// \return true iff tracking is supported by \c MD.
static bool retrack(Metadata *&MD, Metadata *&New) {
return retrack(&MD, *MD, &New);
}
static bool retrack(void *Ref, Metadata &MD, void *New);
/// \brief Check whether metadata is replaceable.
static bool isReplaceable(const Metadata &MD);
typedef PointerUnion<MetadataAsValue *, Metadata *> OwnerTy;
private:
/// \brief Track a reference to metadata for an owner.
///
/// Generalized version of tracking.
static bool track(void *Ref, Metadata &MD, OwnerTy Owner);
};
} // end namespace llvm
#endif

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@ -14,15 +14,11 @@
#ifndef LLVM_IR_TRACKINGMDREF_H #ifndef LLVM_IR_TRACKINGMDREF_H
#define LLVM_IR_TRACKINGMDREF_H #define LLVM_IR_TRACKINGMDREF_H
#include "llvm/IR/MetadataTracking.h" #include "llvm/IR/Metadata.h"
#include "llvm/Support/Casting.h" #include "llvm/Support/Casting.h"
namespace llvm { namespace llvm {
class Metadata;
class MDNode;
class ValueAsMetadata;
/// \brief Tracking metadata reference. /// \brief Tracking metadata reference.
/// ///
/// This class behaves like \a TrackingVH, but for metadata. /// This class behaves like \a TrackingVH, but for metadata.

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@ -36,7 +36,6 @@ add_llvm_library(LLVMCore
MDBuilder.cpp MDBuilder.cpp
Mangler.cpp Mangler.cpp
Metadata.cpp Metadata.cpp
MetadataTracking.cpp
Module.cpp Module.cpp
Operator.cpp Operator.cpp
Pass.cpp Pass.cpp

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@ -120,6 +120,38 @@ void MetadataAsValue::untrack() {
MetadataTracking::untrack(MD); MetadataTracking::untrack(MD);
} }
bool MetadataTracking::track(void *Ref, Metadata &MD, OwnerTy Owner) {
assert(Ref && "Expected live reference");
assert((Owner || *static_cast<Metadata **>(Ref) == &MD) &&
"Reference without owner must be direct");
if (auto *R = ReplaceableMetadataImpl::get(MD)) {
R->addRef(Ref, Owner);
return true;
}
return false;
}
void MetadataTracking::untrack(void *Ref, Metadata &MD) {
assert(Ref && "Expected live reference");
if (auto *R = ReplaceableMetadataImpl::get(MD))
R->dropRef(Ref);
}
bool MetadataTracking::retrack(void *Ref, Metadata &MD, void *New) {
assert(Ref && "Expected live reference");
assert(New && "Expected live reference");
assert(Ref != New && "Expected change");
if (auto *R = ReplaceableMetadataImpl::get(MD)) {
R->moveRef(Ref, New, MD);
return true;
}
return false;
}
bool MetadataTracking::isReplaceable(const Metadata &MD) {
return ReplaceableMetadataImpl::get(const_cast<Metadata &>(MD));
}
void ReplaceableMetadataImpl::addRef(void *Ref, OwnerTy Owner) { void ReplaceableMetadataImpl::addRef(void *Ref, OwnerTy Owner) {
bool WasInserted = bool WasInserted =
UseMap.insert(std::make_pair(Ref, std::make_pair(Owner, NextIndex))) UseMap.insert(std::make_pair(Ref, std::make_pair(Owner, NextIndex)))
@ -239,6 +271,12 @@ void ReplaceableMetadataImpl::resolveAllUses(bool ResolveUsers) {
} }
} }
ReplaceableMetadataImpl *ReplaceableMetadataImpl::get(Metadata &MD) {
if (auto *N = dyn_cast<MDNode>(&MD))
return N->Context.getReplaceableUses();
return dyn_cast<ValueAsMetadata>(&MD);
}
static Function *getLocalFunction(Value *V) { static Function *getLocalFunction(Value *V) {
assert(V && "Expected value"); assert(V && "Expected value");
if (auto *A = dyn_cast<Argument>(V)) if (auto *A = dyn_cast<Argument>(V))

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@ -1,55 +0,0 @@
//===- MetadataTracking.cpp - Implement metadata tracking -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements Metadata tracking.
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/MetadataTracking.h"
#include "llvm/IR/Metadata.h"
using namespace llvm;
ReplaceableMetadataImpl *ReplaceableMetadataImpl::get(Metadata &MD) {
if (auto *N = dyn_cast<MDNode>(&MD))
return N->Context.getReplaceableUses();
return dyn_cast<ValueAsMetadata>(&MD);
}
bool MetadataTracking::track(void *Ref, Metadata &MD, OwnerTy Owner) {
assert(Ref && "Expected live reference");
assert((Owner || *static_cast<Metadata **>(Ref) == &MD) &&
"Reference without owner must be direct");
if (auto *R = ReplaceableMetadataImpl::get(MD)) {
R->addRef(Ref, Owner);
return true;
}
return false;
}
void MetadataTracking::untrack(void *Ref, Metadata &MD) {
assert(Ref && "Expected live reference");
if (auto *R = ReplaceableMetadataImpl::get(MD))
R->dropRef(Ref);
}
bool MetadataTracking::retrack(void *Ref, Metadata &MD, void *New) {
assert(Ref && "Expected live reference");
assert(New && "Expected live reference");
assert(Ref != New && "Expected change");
if (auto *R = ReplaceableMetadataImpl::get(MD)) {
R->moveRef(Ref, New, MD);
return true;
}
return false;
}
bool MetadataTracking::isReplaceable(const Metadata &MD) {
return ReplaceableMetadataImpl::get(const_cast<Metadata &>(MD));
}