Vendor import of clang trunk r178860:

http://llvm.org/svn/llvm-project/cfe/trunk@178860

1 files changed, 109 insertions, 26 deletions

diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp
index 4dfffc4..42c3ba3 100644
--- a/lib/AST/RecordLayoutBuilder.cpp
+++ b/lib/AST/RecordLayoutBuilder.cpp
@@ -7,6 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "clang/AST/RecordLayout.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Attr.h"
 #include "clang/AST/CXXInheritance.h"
@@ -14,13 +15,12 @@
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/Expr.h"
-#include "clang/AST/RecordLayout.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Sema/SemaDiagnostic.h"
-#include "llvm/Support/Format.h"
 #include "llvm/ADT/SmallSet.h"
-#include "llvm/Support/MathExtras.h"
 #include "llvm/Support/CrashRecoveryContext.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/MathExtras.h"
 
 using namespace clang;
 
@@ -676,8 +676,12 @@ protected:
                           bool FieldPacked, const FieldDecl *D);
   void LayoutBitField(const FieldDecl *D);
 
+  TargetCXXABI getCXXABI() const {
+    return Context.getTargetInfo().getCXXABI();
+  }
+
   bool isMicrosoftCXXABI() const {
-    return Context.getTargetInfo().getCXXABI() == CXXABI_Microsoft;
+    return getCXXABI().isMicrosoft();
   }
 
   void MSLayoutVirtualBases(const CXXRecordDecl *RD);
@@ -791,8 +795,6 @@ protected:
 
   RecordLayoutBuilder(const RecordLayoutBuilder &) LLVM_DELETED_FUNCTION;
   void operator=(const RecordLayoutBuilder &) LLVM_DELETED_FUNCTION;
-public:
-  static const CXXMethodDecl *ComputeKeyFunction(const CXXRecordDecl *RD);
 };
 } // end anonymous namespace
 
@@ -2343,8 +2345,8 @@ void RecordLayoutBuilder::CheckFieldPadding(uint64_t Offset,
         << D->getIdentifier();
 }
 
-const CXXMethodDecl *
-RecordLayoutBuilder::ComputeKeyFunction(const CXXRecordDecl *RD) {
+static const CXXMethodDecl *computeKeyFunction(ASTContext &Context,
+                                               const CXXRecordDecl *RD) {
   // If a class isn't polymorphic it doesn't have a key function.
   if (!RD->isPolymorphic())
     return 0;
@@ -2362,6 +2364,9 @@ RecordLayoutBuilder::ComputeKeyFunction(const CXXRecordDecl *RD) {
       TSK == TSK_ExplicitInstantiationDefinition)
     return 0;
 
+  bool allowInlineFunctions =
+    Context.getTargetInfo().getCXXABI().canKeyFunctionBeInline();
+
   for (CXXRecordDecl::method_iterator I = RD->method_begin(),
          E = RD->method_end(); I != E; ++I) {
     const CXXMethodDecl *MD = *I;
@@ -2387,6 +2392,13 @@ RecordLayoutBuilder::ComputeKeyFunction(const CXXRecordDecl *RD) {
     if (!MD->isUserProvided())
       continue;
 
+    // In certain ABIs, ignore functions with out-of-line inline definitions.
+    if (!allowInlineFunctions) {
+      const FunctionDecl *Def;
+      if (MD->hasBody(Def) && Def->isInlineSpecified())
+        continue;
+    }
+
     // We found it.
     return MD;
   }
@@ -2399,6 +2411,48 @@ RecordLayoutBuilder::Diag(SourceLocation Loc, unsigned DiagID) {
   return Context.getDiagnostics().Report(Loc, DiagID);
 }
 
+/// Does the target C++ ABI require us to skip over the tail-padding
+/// of the given class (considering it as a base class) when allocating
+/// objects?
+static bool mustSkipTailPadding(TargetCXXABI ABI, const CXXRecordDecl *RD) {
+  switch (ABI.getTailPaddingUseRules()) {
+  case TargetCXXABI::AlwaysUseTailPadding:
+    return false;
+
+  case TargetCXXABI::UseTailPaddingUnlessPOD03:
+    // FIXME: To the extent that this is meant to cover the Itanium ABI
+    // rules, we should implement the restrictions about over-sized
+    // bitfields:
+    //
+    // http://mentorembedded.github.com/cxx-abi/abi.html#POD :
+    //   In general, a type is considered a POD for the purposes of
+    //   layout if it is a POD type (in the sense of ISO C++
+    //   [basic.types]). However, a POD-struct or POD-union (in the
+    //   sense of ISO C++ [class]) with a bitfield member whose
+    //   declared width is wider than the declared type of the
+    //   bitfield is not a POD for the purpose of layout.  Similarly,
+    //   an array type is not a POD for the purpose of layout if the
+    //   element type of the array is not a POD for the purpose of
+    //   layout.
+    //
+    //   Where references to the ISO C++ are made in this paragraph,
+    //   the Technical Corrigendum 1 version of the standard is
+    //   intended.
+    return RD->isPOD();
+
+  case TargetCXXABI::UseTailPaddingUnlessPOD11:
+    // This is equivalent to RD->getTypeForDecl().isCXX11PODType(),
+    // but with a lot of abstraction penalty stripped off.  This does
+    // assume that these properties are set correctly even in C++98
+    // mode; fortunately, that is true because we want to assign
+    // consistently semantics to the type-traits intrinsics (or at
+    // least as many of them as possible).
+    return RD->isTrivial() && RD->isStandardLayout();
+  }
+
+  llvm_unreachable("bad tail-padding use kind");
+}
+
 /// getASTRecordLayout - Get or compute information about the layout of the
 /// specified record (struct/union/class), which indicates its size and field
 /// position information.
@@ -2443,18 +2497,17 @@ ASTContext::getASTRecordLayout(const RecordDecl *D) const {
       Builder.Layout(RD);
     }
 
-    // FIXME: This is not always correct. See the part about bitfields at
-    // http://www.codesourcery.com/public/cxx-abi/abi.html#POD for more info.
-    // FIXME: IsPODForThePurposeOfLayout should be stored in the record layout.
-    // This does not affect the calculations of MSVC layouts
-    bool IsPODForThePurposeOfLayout = 
-      (!Builder.isMicrosoftCXXABI() && cast<CXXRecordDecl>(D)->isPOD());
+    // In certain situations, we are allowed to lay out objects in the
+    // tail-padding of base classes.  This is ABI-dependent.
+    // FIXME: this should be stored in the record layout.
+    bool skipTailPadding =
+      mustSkipTailPadding(getTargetInfo().getCXXABI(), cast<CXXRecordDecl>(D));
 
     // FIXME: This should be done in FinalizeLayout.
     CharUnits DataSize =
-      IsPODForThePurposeOfLayout ? Builder.getSize() : Builder.getDataSize();
+      skipTailPadding ? Builder.getSize() : Builder.getDataSize();
     CharUnits NonVirtualSize = 
-      IsPODForThePurposeOfLayout ? DataSize : Builder.NonVirtualSize;
+      skipTailPadding ? DataSize : Builder.NonVirtualSize;
 
     NewEntry =
       new (*this) ASTRecordLayout(*this, Builder.getSize(), 
@@ -2492,15 +2545,37 @@ ASTContext::getASTRecordLayout(const RecordDecl *D) const {
   return *NewEntry;
 }
 
-const CXXMethodDecl *ASTContext::getKeyFunction(const CXXRecordDecl *RD) {
+const CXXMethodDecl *ASTContext::getCurrentKeyFunction(const CXXRecordDecl *RD) {
+  assert(RD->getDefinition() && "Cannot get key function for forward decl!");
   RD = cast<CXXRecordDecl>(RD->getDefinition());
-  assert(RD && "Cannot get key function for forward declarations!");
 
-  const CXXMethodDecl *&Entry = KeyFunctions[RD];
-  if (!Entry)
-    Entry = RecordLayoutBuilder::ComputeKeyFunction(RD);
+  const CXXMethodDecl *&entry = KeyFunctions[RD];
+  if (!entry) {
+    entry = computeKeyFunction(*this, RD);
+  }
 
-  return Entry;
+  return entry;
+}
+
+void ASTContext::setNonKeyFunction(const CXXMethodDecl *method) {
+  assert(method == method->getFirstDeclaration() &&
+         "not working with method declaration from class definition");
+
+  // Look up the cache entry.  Since we're working with the first
+  // declaration, its parent must be the class definition, which is
+  // the correct key for the KeyFunctions hash.
+  llvm::DenseMap<const CXXRecordDecl*, const CXXMethodDecl*>::iterator
+    i = KeyFunctions.find(method->getParent());
+
+  // If it's not cached, there's nothing to do.
+  if (i == KeyFunctions.end()) return;
+
+  // If it is cached, check whether it's the target method, and if so,
+  // remove it from the cache.
+  if (i->second == method) {
+    // FIXME: remember that we did this for module / chained PCH state?
+    KeyFunctions.erase(i);
+  }
 }
 
 static uint64_t getFieldOffset(const ASTContext &C, const FieldDecl *FD) {
@@ -2577,6 +2652,11 @@ static void PrintOffset(raw_ostream &OS,
   OS.indent(IndentLevel * 2);
 }
 
+static void PrintIndentNoOffset(raw_ostream &OS, unsigned IndentLevel) {
+  OS << "     | ";
+  OS.indent(IndentLevel * 2);
+}
+
 static void DumpCXXRecordLayout(raw_ostream &OS,
                                 const CXXRecordDecl *RD, const ASTContext &C,
                                 CharUnits Offset,
@@ -2601,7 +2681,7 @@ static void DumpCXXRecordLayout(raw_ostream &OS,
 
   // Vtable pointer.
   if (RD->isDynamicClass() && !PrimaryBase &&
-      C.getTargetInfo().getCXXABI() != CXXABI_Microsoft) {
+      !C.getTargetInfo().getCXXABI().isMicrosoft()) {
     PrintOffset(OS, Offset, IndentLevel);
     OS << '(' << *RD << " vtable pointer)\n";
   }
@@ -2680,11 +2760,14 @@ static void DumpCXXRecordLayout(raw_ostream &OS,
                         /*IncludeVirtualBases=*/false);
   }
 
-  OS << "  sizeof=" << Layout.getSize().getQuantity();
+  PrintIndentNoOffset(OS, IndentLevel - 1);
+  OS << "[sizeof=" << Layout.getSize().getQuantity();
   OS << ", dsize=" << Layout.getDataSize().getQuantity();
   OS << ", align=" << Layout.getAlignment().getQuantity() << '\n';
-  OS << "  nvsize=" << Layout.getNonVirtualSize().getQuantity();
-  OS << ", nvalign=" << Layout.getNonVirtualAlign().getQuantity() << '\n';
+
+  PrintIndentNoOffset(OS, IndentLevel - 1);
+  OS << " nvsize=" << Layout.getNonVirtualSize().getQuantity();
+  OS << ", nvalign=" << Layout.getNonVirtualAlign().getQuantity() << "]\n";
   OS << '\n';
 }