r183466 - Perform dynamic alignment computations so that the data in TypeLocs is

Manuel Klimek klimek at google.com
Fri Jun 7 02:09:38 PDT 2013


More specifically, we get a TemplateSpecializationTypeLoc for which:
getLAngleLoc().isValid() is false, while
getRAngleLoc().isValid() && getLocStart().isValid() &&
getLocEnd().isValid() is true.


On Fri, Jun 7, 2013 at 10:46 AM, Manuel Klimek <klimek at google.com> wrote:

> FYI: this test leads to invalid type source locations in some cases. I
> don't have a good enough repro yet (internal refactoring tests found this),
> but the general idea is this:
> Given a TypeLoc for a templated type A<B> of a function parameter (like
> void f(const A<B>&), trying to getAs<clang::TemplateSpecializationTypeLoc>
> would previously return a valid type loc, and now returns an invalid type
> loc... Is that intentional?
>
> Thanks,
> /Manuel
>
>
>
> On Fri, Jun 7, 2013 at 2:04 AM, Eli Friedman <eli.friedman at gmail.com>wrote:
>
>> Author: efriedma
>> Date: Thu Jun  6 19:04:31 2013
>> New Revision: 183466
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=183466&view=rev
>> Log:
>> Perform dynamic alignment computations so that the data in TypeLocs is
>> correctly aligned.  Not performing such computations led to misaligned
>> loads,
>> which crash on some platforms and are generally bad on other platforms.
>>
>> The implementation of TypeLocBuilder::pushImpl is rather messy; code using
>> TypeLocBuilder accidentally assumes that partial TypeLocs are
>> laid out like a complete TypeLoc.  As a followup, I intend to work on
>> fixing the TypeLocBuilder API to avoid exposing partial TypeLocs; this
>> should
>> substantially simplify the implemementation.
>>
>> Fixes PR16144.
>>
>>
>> Added:
>>     cfe/trunk/lib/Sema/TypeLocBuilder.cpp
>> Modified:
>>     cfe/trunk/include/clang/AST/TypeLoc.h
>>     cfe/trunk/lib/AST/TypeLoc.cpp
>>     cfe/trunk/lib/Sema/CMakeLists.txt
>>     cfe/trunk/lib/Sema/SemaLambda.cpp
>>     cfe/trunk/lib/Sema/SemaTemplateVariadic.cpp
>>     cfe/trunk/lib/Sema/TreeTransform.h
>>     cfe/trunk/lib/Sema/TypeLocBuilder.h
>>
>> Modified: cfe/trunk/include/clang/AST/TypeLoc.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/TypeLoc.h?rev=183466&r1=183465&r2=183466&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/include/clang/AST/TypeLoc.h (original)
>> +++ cfe/trunk/include/clang/AST/TypeLoc.h Thu Jun  6 19:04:31 2013
>> @@ -95,6 +95,10 @@ public:
>>    /// \brief Returns the size of type source info data block for the
>> given type.
>>    static unsigned getFullDataSizeForType(QualType Ty);
>>
>> +  /// \brief Returns the alignment of type source info data block for
>> +  /// the given type.
>> +  static unsigned getLocalAlignmentForType(QualType Ty);
>> +
>>    /// \brief Get the type for which this source info wrapper provides
>>    /// information.
>>    QualType getType() const {
>> @@ -229,7 +233,11 @@ public:
>>    }
>>
>>    UnqualTypeLoc getUnqualifiedLoc() const {
>> -    return UnqualTypeLoc(getTypePtr(), Data);
>> +    unsigned align =
>> +        TypeLoc::getLocalAlignmentForType(QualType(getTypePtr(), 0));
>> +    uintptr_t dataInt = reinterpret_cast<uintptr_t>(Data);
>> +    dataInt = llvm::RoundUpToAlignment(dataInt, align);
>> +    return UnqualTypeLoc(getTypePtr(), reinterpret_cast<void*>(dataInt));
>>    }
>>
>>    /// Initializes the local data of this type source info block to
>> @@ -250,10 +258,11 @@ public:
>>      return 0;
>>    }
>>
>> -  /// \brief Returns the size of the type source info data block.
>> -  unsigned getFullDataSize() const {
>> -    return getLocalDataSize() +
>> -      getFullDataSizeForType(getType().getLocalUnqualifiedType());
>> +  /// \brief Returns the alignment of the type source info data block
>> that is
>> +  /// specific to this type.
>> +  unsigned getLocalDataAlignment() const {
>> +    // We don't preserve any location information.
>> +    return 1;
>>    }
>>
>>  private:
>> @@ -280,9 +289,6 @@ inline UnqualTypeLoc TypeLoc::getUnquali
>>  /// \tparam LocalData the structure type of local location data for
>>  ///   this type
>>  ///
>> -/// sizeof(LocalData) needs to be a multiple of sizeof(void*) or
>> -/// else the world will end.
>> -///
>>  /// TypeLocs with non-constant amounts of local data should override
>>  /// getExtraLocalDataSize(); getExtraLocalData() will then point to
>>  /// this extra memory.
>> @@ -317,12 +323,16 @@ class ConcreteTypeLoc : public Base {
>>    }
>>
>>  public:
>> -  unsigned getLocalDataSize() const {
>> -    return sizeof(LocalData) + asDerived()->getExtraLocalDataSize();
>> +  unsigned getLocalDataAlignment() const {
>> +    return std::max(llvm::alignOf<LocalData>(),
>> +                    asDerived()->getExtraLocalDataAlignment());
>>    }
>> -  // Give a default implementation that's useful for leaf types.
>> -  unsigned getFullDataSize() const {
>> -    return asDerived()->getLocalDataSize() + getInnerTypeSize();
>> +  unsigned getLocalDataSize() const {
>> +    unsigned size = sizeof(LocalData);
>> +    unsigned extraAlign = asDerived()->getExtraLocalDataAlignment();
>> +    size = llvm::RoundUpToAlignment(size, extraAlign);
>> +    size += asDerived()->getExtraLocalDataSize();
>> +    return size;
>>    }
>>
>>    TypeLoc getNextTypeLoc() const {
>> @@ -338,6 +348,10 @@ protected:
>>      return 0;
>>    }
>>
>> +  unsigned getExtraLocalDataAlignment() const {
>> +    return 1;
>> +  }
>> +
>>    LocalData *getLocalData() const {
>>      return static_cast<LocalData*>(Base::Data);
>>    }
>> @@ -346,11 +360,17 @@ protected:
>>    /// local data that can't be captured in the Info (e.g. because it's
>>    /// of variable size).
>>    void *getExtraLocalData() const {
>> -    return getLocalData() + 1;
>> +    unsigned size = sizeof(LocalData);
>> +    unsigned extraAlign = asDerived()->getExtraLocalDataAlignment();
>> +    size = llvm::RoundUpToAlignment(size, extraAlign);
>> +    return reinterpret_cast<char*>(Base::Data) + size;
>>    }
>>
>>    void *getNonLocalData() const {
>> -    return static_cast<char*>(Base::Data) +
>> asDerived()->getLocalDataSize();
>> +    uintptr_t data = reinterpret_cast<uintptr_t>(Base::Data);
>> +    data += asDerived()->getLocalDataSize();
>> +    data = llvm::RoundUpToAlignment(data, getNextTypeAlign());
>> +    return reinterpret_cast<void*>(data);
>>    }
>>
>>    struct HasNoInnerType {};
>> @@ -373,6 +393,18 @@ private:
>>      return getInnerTypeLoc().getFullDataSize();
>>    }
>>
>> +  unsigned getNextTypeAlign() const {
>> +    return getNextTypeAlign(asDerived()->getInnerType());
>> +  }
>> +
>> +  unsigned getNextTypeAlign(HasNoInnerType _) const {
>> +    return 1;
>> +  }
>> +
>> +  unsigned getNextTypeAlign(QualType T) const {
>> +    return TypeLoc::getLocalAlignmentForType(T);
>> +  }
>> +
>>    TypeLoc getNextTypeLoc(HasNoInnerType _) const {
>>      return TypeLoc();
>>    }
>> @@ -417,7 +449,8 @@ class TypeSpecTypeLoc : public ConcreteT
>>                                                 Type,
>>                                                 TypeSpecLocInfo> {
>>  public:
>> -  enum { LocalDataSize = sizeof(TypeSpecLocInfo) };
>> +  enum { LocalDataSize = sizeof(TypeSpecLocInfo),
>> +         LocalDataAlignment = llvm::AlignOf<TypeSpecLocInfo>::Alignment
>> };
>>
>>    SourceLocation getNameLoc() const {
>>      return this->getLocalData()->NameLoc;
>> @@ -448,8 +481,6 @@ class BuiltinTypeLoc : public ConcreteTy
>>                                                BuiltinType,
>>                                                BuiltinLocInfo> {
>>  public:
>> -  enum { LocalDataSize = sizeof(BuiltinLocInfo) };
>> -
>>    SourceLocation getBuiltinLoc() const {
>>      return getLocalData()->BuiltinLoc;
>>    }
>> @@ -478,6 +509,10 @@ public:
>>      return needsExtraLocalData() ? sizeof(WrittenBuiltinSpecs) : 0;
>>    }
>>
>> +  unsigned getExtraLocalDataAlignment() const {
>> +    return needsExtraLocalData() ? llvm::alignOf<WrittenBuiltinSpecs>()
>> : 1;
>> +  }
>> +
>>    SourceRange getLocalSourceRange() const {
>>      return SourceRange(getBuiltinLoc(), getBuiltinLoc());
>>    }
>> @@ -840,6 +875,10 @@ public:
>>      return this->getNumProtocols() * sizeof(SourceLocation);
>>    }
>>
>> +  unsigned getExtraLocalDataAlignment() const {
>> +    return llvm::alignOf<SourceLocation>();
>> +  }
>> +
>>    QualType getInnerType() const {
>>      return getTypePtr()->getBaseType();
>>    }
>> @@ -1166,6 +1205,10 @@ public:
>>      return getNumArgs() * sizeof(ParmVarDecl*);
>>    }
>>
>> +  unsigned getExtraLocalDataAlignment() const {
>> +    return llvm::alignOf<ParmVarDecl*>();
>> +  }
>> +
>>    QualType getInnerType() const { return getTypePtr()->getResultType(); }
>>  };
>>
>> @@ -1357,6 +1400,10 @@ public:
>>      return getNumArgs() * sizeof(TemplateArgumentLocInfo);
>>    }
>>
>> +  unsigned getExtraLocalDataAlignment() const {
>> +    return llvm::alignOf<TemplateArgumentLocInfo>();
>> +  }
>> +
>>  private:
>>    TemplateArgumentLocInfo *getArgInfos() const {
>>      return static_cast<TemplateArgumentLocInfo*>(getExtraLocalData());
>> @@ -1761,6 +1808,10 @@ public:
>>      return getNumArgs() * sizeof(TemplateArgumentLocInfo);
>>    }
>>
>> +  unsigned getExtraLocalDataAlignment() const {
>> +    return llvm::alignOf<TemplateArgumentLocInfo>();
>> +  }
>> +
>>  private:
>>    TemplateArgumentLocInfo *getArgInfos() const {
>>      return static_cast<TemplateArgumentLocInfo*>(getExtraLocalData());
>>
>> Modified: cfe/trunk/lib/AST/TypeLoc.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/TypeLoc.cpp?rev=183466&r1=183465&r2=183466&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/AST/TypeLoc.cpp (original)
>> +++ cfe/trunk/lib/AST/TypeLoc.cpp Thu Jun  6 19:04:31 2013
>> @@ -41,12 +41,30 @@ SourceRange TypeLoc::getLocalSourceRange
>>  }
>>
>>  namespace {
>> +  class TypeAligner : public TypeLocVisitor<TypeAligner, unsigned> {
>> +  public:
>> +#define ABSTRACT_TYPELOC(CLASS, PARENT)
>> +#define TYPELOC(CLASS, PARENT) \
>> +    unsigned Visit##CLASS##TypeLoc(CLASS##TypeLoc TyLoc) { \
>> +      return TyLoc.getLocalDataAlignment(); \
>> +    }
>> +#include "clang/AST/TypeLocNodes.def"
>> +  };
>> +}
>> +
>> +/// \brief Returns the alignment of the type source info data block.
>> +unsigned TypeLoc::getLocalAlignmentForType(QualType Ty) {
>> +  if (Ty.isNull()) return 1;
>> +  return TypeAligner().Visit(TypeLoc(Ty, 0));
>> +}
>> +
>> +namespace {
>>    class TypeSizer : public TypeLocVisitor<TypeSizer, unsigned> {
>>    public:
>>  #define ABSTRACT_TYPELOC(CLASS, PARENT)
>>  #define TYPELOC(CLASS, PARENT) \
>>      unsigned Visit##CLASS##TypeLoc(CLASS##TypeLoc TyLoc) { \
>> -      return TyLoc.getFullDataSize(); \
>> +      return TyLoc.getLocalDataSize(); \
>>      }
>>  #include "clang/AST/TypeLocNodes.def"
>>    };
>> @@ -54,8 +72,18 @@ namespace {
>>
>>  /// \brief Returns the size of the type source info data block.
>>  unsigned TypeLoc::getFullDataSizeForType(QualType Ty) {
>> -  if (Ty.isNull()) return 0;
>> -  return TypeSizer().Visit(TypeLoc(Ty, 0));
>> +  unsigned Total = 0;
>> +  TypeLoc TyLoc(Ty, 0);
>> +  unsigned MaxAlign = 1;
>> +  while (!TyLoc.isNull()) {
>> +    unsigned Align = getLocalAlignmentForType(TyLoc.getType());
>> +    MaxAlign = std::max(Align, MaxAlign);
>> +    Total = llvm::RoundUpToAlignment(Total, Align);
>> +    Total += TypeSizer().Visit(TyLoc);
>> +    TyLoc = TyLoc.getNextTypeLoc();
>> +  }
>> +  Total = llvm::RoundUpToAlignment(Total, MaxAlign);
>> +  return Total;
>>  }
>>
>>  namespace {
>>
>> Modified: cfe/trunk/lib/Sema/CMakeLists.txt
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/CMakeLists.txt?rev=183466&r1=183465&r2=183466&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/CMakeLists.txt (original)
>> +++ cfe/trunk/lib/Sema/CMakeLists.txt Thu Jun  6 19:04:31 2013
>> @@ -51,6 +51,7 @@ add_clang_library(clangSema
>>    SemaTemplateVariadic.cpp
>>    SemaType.cpp
>>    TargetAttributesSema.cpp
>> +  TypeLocBuilder.cpp
>>    )
>>
>>  add_dependencies(clangSema
>>
>> Modified: cfe/trunk/lib/Sema/SemaLambda.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaLambda.cpp?rev=183466&r1=183465&r2=183466&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/SemaLambda.cpp (original)
>> +++ cfe/trunk/lib/Sema/SemaLambda.cpp Thu Jun  6 19:04:31 2013
>> @@ -445,6 +445,7 @@ FieldDecl *Sema::checkInitCapture(Source
>>      assert(!DeductType.isNull() && "can't build reference to auto");
>>      TLB.push<ReferenceTypeLoc>(DeductType).setSigilLoc(Loc);
>>    }
>> +  TypeSourceInfo *TSI = TLB.getTypeSourceInfo(Context, DeductType);
>>
>>    InitializationKind InitKind = InitializationKind::CreateDefault(Loc);
>>    Expr *Init = InitExpr;
>> @@ -476,8 +477,7 @@ FieldDecl *Sema::checkInitCapture(Source
>>    else
>>      InitKind = InitializationKind::CreateCopy(Loc, Loc);
>>    QualType DeducedType;
>> -  if (DeduceAutoType(TLB.getTemporaryTypeLoc(DeductType),
>> -                     Init, DeducedType) == DAR_Failed) {
>> +  if (DeduceAutoType(TSI, Init, DeducedType) == DAR_Failed) {
>>      if (isa<InitListExpr>(Init))
>>        Diag(Loc, diag::err_init_capture_deduction_failure_from_init_list)
>>            << Id << Init->getSourceRange();
>> @@ -492,7 +492,7 @@ FieldDecl *Sema::checkInitCapture(Source
>>    //   the closure type. This member is not a bit-field and not mutable.
>>    // Core issue: the member is (probably...) public.
>>    FieldDecl *NewFD = CheckFieldDecl(
>> -      Id, DeducedType, TLB.getTypeSourceInfo(Context, DeductType),
>> LSI->Lambda,
>> +      Id, DeducedType, TSI, LSI->Lambda,
>>        Loc, /*Mutable*/ false, /*BitWidth*/ 0, ICIS_NoInit,
>>        Loc, AS_public, /*PrevDecl*/ 0, /*Declarator*/ 0);
>>    LSI->Lambda->addDecl(NewFD);
>>
>> Modified: cfe/trunk/lib/Sema/SemaTemplateVariadic.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplateVariadic.cpp?rev=183466&r1=183465&r2=183466&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/SemaTemplateVariadic.cpp (original)
>> +++ cfe/trunk/lib/Sema/SemaTemplateVariadic.cpp Thu Jun  6 19:04:31 2013
>> @@ -18,6 +18,7 @@
>>  #include "clang/Sema/ScopeInfo.h"
>>  #include "clang/Sema/SemaInternal.h"
>>  #include "clang/Sema/Template.h"
>> +#include "TypeLocBuilder.h"
>>
>>  using namespace clang;
>>
>> @@ -463,17 +464,13 @@ Sema::CheckPackExpansion(TypeSourceInfo
>>                                         EllipsisLoc, NumExpansions);
>>    if (Result.isNull())
>>      return 0;
>> -
>> -  TypeSourceInfo *TSResult = Context.CreateTypeSourceInfo(Result);
>> -  PackExpansionTypeLoc TL =
>> -      TSResult->getTypeLoc().castAs<PackExpansionTypeLoc>();
>> +
>> +  TypeLocBuilder TLB;
>> +  TLB.pushFullCopy(Pattern->getTypeLoc());
>> +  PackExpansionTypeLoc TL = TLB.push<PackExpansionTypeLoc>(Result);
>>    TL.setEllipsisLoc(EllipsisLoc);
>> -
>> -  // Copy over the source-location information from the type.
>> -  memcpy(TL.getNextTypeLoc().getOpaqueData(),
>> -         Pattern->getTypeLoc().getOpaqueData(),
>> -         Pattern->getTypeLoc().getFullDataSize());
>> -  return TSResult;
>> +
>> +  return TLB.getTypeSourceInfo(Context, Result);
>>  }
>>
>>  QualType Sema::CheckPackExpansion(QualType Pattern, SourceRange
>> PatternRange,
>>
>> Modified: cfe/trunk/lib/Sema/TreeTransform.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/TreeTransform.h?rev=183466&r1=183465&r2=183466&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/TreeTransform.h (original)
>> +++ cfe/trunk/lib/Sema/TreeTransform.h Thu Jun  6 19:04:31 2013
>> @@ -3427,7 +3427,7 @@ TreeTransform<Derived>::TransformQualifi
>>        } else {
>>          // Otherwise, complain about the addition of a qualifier to an
>>          // already-qualified type.
>> -        SourceRange R = TLB.getTemporaryTypeLoc(Result).getSourceRange();
>> +        SourceRange R = T.getUnqualifiedLoc().getSourceRange();
>>          SemaRef.Diag(R.getBegin(),
>> diag::err_attr_objc_ownership_redundant)
>>            << Result << R;
>>
>>
>> Added: cfe/trunk/lib/Sema/TypeLocBuilder.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/TypeLocBuilder.cpp?rev=183466&view=auto
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/TypeLocBuilder.cpp (added)
>> +++ cfe/trunk/lib/Sema/TypeLocBuilder.cpp Thu Jun  6 19:04:31 2013
>> @@ -0,0 +1,136 @@
>> +//===--- TypeLocBuilder.cpp - Type Source Info collector
>> ------------------===//
>> +//
>> +//                     The LLVM Compiler Infrastructure
>> +//
>> +// This file is distributed under the University of Illinois Open Source
>> +// License. See LICENSE.TXT for details.
>> +//
>>
>> +//===----------------------------------------------------------------------===//
>> +//
>> +//  This files defines TypeLocBuilder, a class for building TypeLocs
>> +//  bottom-up.
>> +//
>>
>> +//===----------------------------------------------------------------------===//
>> +
>> +#include "TypeLocBuilder.h"
>> +
>> +using namespace clang;
>> +
>> +void TypeLocBuilder::pushFullCopy(TypeLoc L) {
>> +  size_t Size = L.getFullDataSize();
>> +  reserve(Size);
>> +
>> +  SmallVector<TypeLoc, 4> TypeLocs;
>> +  TypeLoc CurTL = L;
>> +  while (CurTL) {
>> +    TypeLocs.push_back(CurTL);
>> +    CurTL = CurTL.getNextTypeLoc();
>> +  }
>> +
>> +  for (unsigned i = 0, e = TypeLocs.size(); i < e; ++i) {
>> +    TypeLoc CurTL = TypeLocs[e-i-1];
>> +    switch (CurTL.getTypeLocClass()) {
>> +#define ABSTRACT_TYPELOC(CLASS, PARENT)
>> +#define TYPELOC(CLASS, PARENT) \
>> +    case TypeLoc::CLASS: { \
>> +      CLASS##TypeLoc NewTL = push<class
>> CLASS##TypeLoc>(CurTL.getType()); \
>> +      memcpy(NewTL.getOpaqueData(), CurTL.getOpaqueData(),
>> NewTL.getLocalDataSize()); \
>> +      break; \
>> +    }
>> +#include "clang/AST/TypeLocNodes.def"
>> +    }
>> +  }
>> +}
>> +
>> +void TypeLocBuilder::grow(size_t NewCapacity) {
>> +  assert(NewCapacity > Capacity);
>> +
>> +  // Allocate the new buffer and copy the old data into it.
>> +  char *NewBuffer = new char[NewCapacity];
>> +  unsigned NewIndex = Index + NewCapacity - Capacity;
>> +  memcpy(&NewBuffer[NewIndex],
>> +         &Buffer[Index],
>> +         Capacity - Index);
>> +
>> +  if (Buffer != InlineBuffer.buffer)
>> +    delete[] Buffer;
>> +
>> +  Buffer = NewBuffer;
>> +  Capacity = NewCapacity;
>> +  Index = NewIndex;
>> +}
>> +
>> +TypeLoc TypeLocBuilder::pushImpl(QualType T, size_t LocalSize, unsigned
>> LocalAlignment) {
>> +#ifndef NDEBUG
>> +  QualType TLast = TypeLoc(T, 0).getNextTypeLoc().getType();
>> +  assert(TLast == LastTy &&
>> +         "mismatch between last type and new type's inner type");
>> +  LastTy = T;
>> +#endif
>> +
>> +  assert(LocalAlignment <= BufferMaxAlignment && "Unexpected alignment");
>> +
>> +  // If we need to grow, grow by a factor of 2.
>> +  if (LocalSize > Index) {
>> +    size_t RequiredCapacity = Capacity + (LocalSize - Index);
>> +    size_t NewCapacity = Capacity * 2;
>> +    while (RequiredCapacity > NewCapacity)
>> +      NewCapacity *= 2;
>> +    grow(NewCapacity);
>> +  }
>> +
>> +  // Because we're adding elements to the TypeLoc backwards, we have to
>> +  // do some extra work to keep everything aligned appropriately.
>> +  // FIXME: This algorithm is a absolute mess because every TypeLoc
>> returned
>> +  // needs to be valid.  Partial TypeLocs are a terrible idea.
>> +  // FIXME: 4 and 8 are sufficient at the moment, but it's pretty ugly to
>> +  // hardcode them.
>> +  if (LocalAlignment == 4) {
>> +    if (NumBytesAtAlign8 == 0) {
>> +      NumBytesAtAlign4 += LocalSize;
>> +    } else {
>> +      unsigned Padding = NumBytesAtAlign4 % 8;
>> +      if (Padding == 0) {
>> +        if (LocalSize % 8 == 0) {
>> +          // Everything is set: there's no padding and we don't need to
>> add
>> +          // any.
>> +        } else {
>> +          assert(LocalSize % 8 == 4);
>> +          // No existing padding; add in 4 bytes padding
>> +          memmove(&Buffer[Index - 4], &Buffer[Index], NumBytesAtAlign4);
>> +          Index -= 4;
>> +        }
>> +      } else {
>> +        assert(Padding == 4);
>> +        if (LocalSize % 8 == 0) {
>> +          // Everything is set: there's 4 bytes padding and we don't need
>> +          // to add any.
>> +        } else {
>> +          assert(LocalSize % 8 == 4);
>> +          // There are 4 bytes padding, but we don't need any; remove it.
>> +          memmove(&Buffer[Index + 4], &Buffer[Index], NumBytesAtAlign4);
>> +          Index += 4;
>> +        }
>> +      }
>> +      NumBytesAtAlign4 += LocalSize;
>> +    }
>> +  } else if (LocalAlignment == 8) {
>> +    if (!NumBytesAtAlign8 && NumBytesAtAlign4 % 8 != 0) {
>> +      // No existing padding and misaligned members; add in 4 bytes
>> padding
>> +      memmove(&Buffer[Index - 4], &Buffer[Index], NumBytesAtAlign4);
>> +      Index -= 4;
>> +    }
>> +    // Forget about any padding.
>> +    NumBytesAtAlign4 = 0;
>> +    NumBytesAtAlign8 += LocalSize;
>> +  } else {
>> +    assert(LocalSize == 0);
>> +  }
>> +
>> +  Index -= LocalSize;
>> +
>> +  assert(Capacity - Index == TypeLoc::getFullDataSizeForType(T) &&
>> +         "incorrect data size provided to CreateTypeSourceInfo!");
>> +
>> +  return getTemporaryTypeLoc(T);
>> +}
>>
>> Modified: cfe/trunk/lib/Sema/TypeLocBuilder.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/TypeLocBuilder.h?rev=183466&r1=183465&r2=183466&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/TypeLocBuilder.h (original)
>> +++ cfe/trunk/lib/Sema/TypeLocBuilder.h Thu Jun  6 19:04:31 2013
>> @@ -39,14 +39,19 @@ class TypeLocBuilder {
>>  #endif
>>
>>    /// The inline buffer.
>> -  char InlineBuffer[InlineCapacity];
>> +  enum { BufferMaxAlignment = llvm::AlignOf<void*>::Alignment };
>> +  llvm::AlignedCharArray<BufferMaxAlignment, InlineCapacity>
>> InlineBuffer;
>> +  unsigned NumBytesAtAlign4, NumBytesAtAlign8;
>>
>>   public:
>>    TypeLocBuilder()
>> -    : Buffer(InlineBuffer), Capacity(InlineCapacity),
>> Index(InlineCapacity) {}
>> +    : Buffer(InlineBuffer.buffer), Capacity(InlineCapacity),
>> +      Index(InlineCapacity), NumBytesAtAlign4(0), NumBytesAtAlign8(0)
>> +  {
>> +  }
>>
>>    ~TypeLocBuilder() {
>> -    if (Buffer != InlineBuffer)
>> +    if (Buffer != InlineBuffer.buffer)
>>        delete[] Buffer;
>>    }
>>
>> @@ -59,23 +64,14 @@ class TypeLocBuilder {
>>
>>    /// Pushes a copy of the given TypeLoc onto this builder.  The builder
>>    /// must be empty for this to work.
>> -  void pushFullCopy(TypeLoc L) {
>> -    size_t Size = L.getFullDataSize();
>> -    TypeLoc Copy = pushFullUninitializedImpl(L.getType(), Size);
>> -    memcpy(Copy.getOpaqueData(), L.getOpaqueData(), Size);
>> -  }
>> -
>> -  /// Pushes uninitialized space for the given type.  The builder must
>> -  /// be empty.
>> -  TypeLoc pushFullUninitialized(QualType T) {
>> -    return pushFullUninitializedImpl(T,
>> TypeLoc::getFullDataSizeForType(T));
>> -  }
>> +  void pushFullCopy(TypeLoc L);
>>
>>    /// Pushes space for a typespec TypeLoc.  Invalidates any TypeLocs
>>    /// previously retrieved from this builder.
>>    TypeSpecTypeLoc pushTypeSpec(QualType T) {
>>      size_t LocalSize = TypeSpecTypeLoc::LocalDataSize;
>> -    return pushImpl(T, LocalSize).castAs<TypeSpecTypeLoc>();
>> +    unsigned LocalAlign = TypeSpecTypeLoc::LocalDataAlignment;
>> +    return pushImpl(T, LocalSize, LocalAlign).castAs<TypeSpecTypeLoc>();
>>    }
>>
>>    /// Resets this builder to the newly-initialized state.
>> @@ -84,6 +80,7 @@ class TypeLocBuilder {
>>      LastTy = QualType();
>>  #endif
>>      Index = Capacity;
>> +    NumBytesAtAlign4 = NumBytesAtAlign8 = 0;
>>    }
>>
>>    /// \brief Tell the TypeLocBuilder that the type it is storing has been
>> @@ -97,8 +94,10 @@ class TypeLocBuilder {
>>    /// Pushes space for a new TypeLoc of the given type.  Invalidates
>>    /// any TypeLocs previously retrieved from this builder.
>>    template <class TyLocType> TyLocType push(QualType T) {
>> -    size_t LocalSize = TypeLoc(T,
>> 0).castAs<TyLocType>().getLocalDataSize();
>> -    return pushImpl(T, LocalSize).castAs<TyLocType>();
>> +    TyLocType Loc = TypeLoc(T, 0).castAs<TyLocType>();
>> +    size_t LocalSize = Loc.getLocalDataSize();
>> +    unsigned LocalAlign = Loc.getLocalDataAlignment();
>> +    return pushImpl(T, LocalSize, LocalAlign).castAs<TyLocType>();
>>    }
>>
>>    /// Creates a TypeSourceInfo for the given type.
>> @@ -127,61 +126,12 @@ class TypeLocBuilder {
>>    }
>>
>>  private:
>> -  TypeLoc pushImpl(QualType T, size_t LocalSize) {
>> -#ifndef NDEBUG
>> -    QualType TLast = TypeLoc(T, 0).getNextTypeLoc().getType();
>> -    assert(TLast == LastTy &&
>> -           "mismatch between last type and new type's inner type");
>> -    LastTy = T;
>> -#endif
>> -
>> -    // If we need to grow, grow by a factor of 2.
>> -    if (LocalSize > Index) {
>> -      size_t RequiredCapacity = Capacity + (LocalSize - Index);
>> -      size_t NewCapacity = Capacity * 2;
>> -      while (RequiredCapacity > NewCapacity)
>> -        NewCapacity *= 2;
>> -      grow(NewCapacity);
>> -    }
>>
>> -    Index -= LocalSize;
>> -
>> -    return getTemporaryTypeLoc(T);
>> -  }
>> +  TypeLoc pushImpl(QualType T, size_t LocalSize, unsigned
>> LocalAlignment);
>>
>>    /// Grow to the given capacity.
>> -  void grow(size_t NewCapacity) {
>> -    assert(NewCapacity > Capacity);
>> -
>> -    // Allocate the new buffer and copy the old data into it.
>> -    char *NewBuffer = new char[NewCapacity];
>> -    unsigned NewIndex = Index + NewCapacity - Capacity;
>> -    memcpy(&NewBuffer[NewIndex],
>> -           &Buffer[Index],
>> -           Capacity - Index);
>> -
>> -    if (Buffer != InlineBuffer)
>> -      delete[] Buffer;
>> -
>> -    Buffer = NewBuffer;
>> -    Capacity = NewCapacity;
>> -    Index = NewIndex;
>> -  }
>> -
>> -  TypeLoc pushFullUninitializedImpl(QualType T, size_t Size) {
>> -#ifndef NDEBUG
>> -    assert(LastTy.isNull() && "pushing full on non-empty
>> TypeLocBuilder");
>> -    LastTy = T;
>> -#endif
>> -    assert(Index == Capacity && "pushing full on non-empty
>> TypeLocBuilder");
>> -
>> -    reserve(Size);
>> -    Index -= Size;
>> -
>> -    return getTemporaryTypeLoc(T);
>> -  }
>> +  void grow(size_t NewCapacity);
>>
>> -public:
>>    /// \brief Retrieve a temporary TypeLoc that refers into this \c
>> TypeLocBuilder
>>    /// object.
>>    ///
>>
>>
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>>
>
>
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