Change how we distinguish bitfield widths, in-class

initializers, and captured VLA types so that we can
answer questions like "is this a bit-field" without
looking at the enclosing DeclContext.  NFC.

llvm-svn: 219522

3 files changed, 30 insertions, 45 deletions

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index aec7059490c..e3e365ff0f3 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -3282,18 +3282,9 @@ bool FieldDecl::isAnonymousStructOrUnion() const {
   return false;
 }
 
-bool FieldDecl::isBitField() const {
-  if (getInClassInitStyle() == ICIS_NoInit &&
-      InitializerOrBitWidth.getPointer()) {
-    assert(getDeclContext() && "No parent context for FieldDecl");
-    return !getDeclContext()->isRecord() || !getParent()->isLambda();
-  }
-  return false;
-}
-
 unsigned FieldDecl::getBitWidthValue(const ASTContext &Ctx) const {
   assert(isBitField() && "not a bitfield");
-  Expr *BitWidth = static_cast<Expr *>(InitializerOrBitWidth.getPointer());
+  Expr *BitWidth = static_cast<Expr *>(InitStorage.getPointer());
   return BitWidth->EvaluateKnownConstInt(Ctx).getZExtValue();
 }
 
@@ -3317,34 +3308,28 @@ unsigned FieldDecl::getFieldIndex() const {
 }
 
 SourceRange FieldDecl::getSourceRange() const {
-  if (const Expr *E =
-          static_cast<const Expr *>(InitializerOrBitWidth.getPointer()))
-    return SourceRange(getInnerLocStart(), E->getLocEnd());
-  return DeclaratorDecl::getSourceRange();
-}
+  switch (InitStorage.getInt()) {
+  // All three of these cases store an optional Expr*.
+  case ISK_BitWidthOrNothing:
+  case ISK_InClassCopyInit:
+  case ISK_InClassListInit:
+    if (const Expr *E = static_cast<const Expr *>(InitStorage.getPointer()))
+      return SourceRange(getInnerLocStart(), E->getLocEnd());
+    // FALLTHROUGH
 
-void FieldDecl::setBitWidth(Expr *Width) {
-  assert(!InitializerOrBitWidth.getPointer() && !hasInClassInitializer() &&
-         "bit width, initializer or captured type already set");
-  InitializerOrBitWidth.setPointer(Width);
-}
-
-void FieldDecl::setInClassInitializer(Expr *Init) {
-  assert(!InitializerOrBitWidth.getPointer() && hasInClassInitializer() &&
-         "bit width, initializer or captured expr already set");
-  InitializerOrBitWidth.setPointer(Init);
-}
-
-bool FieldDecl::hasCapturedVLAType() const {
-  return getDeclContext()->isRecord() && getParent()->isLambda() &&
-         InitializerOrBitWidth.getPointer();
+  case ISK_CapturedVLAType:
+    return DeclaratorDecl::getSourceRange();
+  }
+  llvm_unreachable("bad init storage kind");
 }
 
 void FieldDecl::setCapturedVLAType(const VariableArrayType *VLAType) {
   assert(getParent()->isLambda() && "capturing type in non-lambda.");
-  assert(!InitializerOrBitWidth.getPointer() && !hasInClassInitializer() &&
+  assert(InitStorage.getInt() == ISK_BitWidthOrNothing &&
+         InitStorage.getPointer() == nullptr &&
          "bit width, initializer or captured type already set");
-  InitializerOrBitWidth.setPointer(const_cast<VariableArrayType *>(VLAType));
+  InitStorage.setPointerAndInt(const_cast<VariableArrayType *>(VLAType),
+                               ISK_CapturedVLAType);
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 1c52b200967..93cd932a618 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -1000,13 +1000,14 @@ void ASTDeclReader::VisitFieldDecl(FieldDecl *FD) {
   VisitDeclaratorDecl(FD);
   FD->Mutable = Record[Idx++];
   if (int BitWidthOrInitializer = Record[Idx++]) {
-    FD->InitializerOrBitWidth.setInt(BitWidthOrInitializer - 1);
-    if (FD->getDeclContext()->isRecord() && FD->getParent()->isLambda()) {
+    FD->InitStorage.setInt(
+          static_cast<FieldDecl::InitStorageKind>(BitWidthOrInitializer - 1));
+    if (FD->InitStorage.getInt() == FieldDecl::ISK_CapturedVLAType) {
       // Read captured variable length array.
-      FD->InitializerOrBitWidth.setPointer(
+      FD->InitStorage.setPointer(
           Reader.readType(F, Record, Idx).getAsOpaquePtr());
     } else {
-      FD->InitializerOrBitWidth.setPointer(Reader.ReadExpr(F));
+      FD->InitStorage.setPointer(Reader.ReadExpr(F));
     }
   }
   if (!FD->getDeclName()) {
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 0549851cbf2..489996825be 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -677,18 +677,17 @@ void ASTDeclWriter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
 void ASTDeclWriter::VisitFieldDecl(FieldDecl *D) {
   VisitDeclaratorDecl(D);
   Record.push_back(D->isMutable());
-  if ((D->InitializerOrBitWidth.getInt() != ICIS_NoInit ||
-       D->InitializerOrBitWidth.getPointer()) &&
-      !D->hasCapturedVLAType()) {
-    Record.push_back(D->InitializerOrBitWidth.getInt() + 1);
-    Writer.AddStmt(static_cast<Expr *>(D->InitializerOrBitWidth.getPointer()));
-  } else if (D->hasCapturedVLAType()) {
-    Record.push_back(D->InitializerOrBitWidth.getInt() + 1);
+  if (D->InitStorage.getInt() == FieldDecl::ISK_BitWidthOrNothing &&
+      D->InitStorage.getPointer() == nullptr) {
+    Record.push_back(0);
+  } else if (D->InitStorage.getInt() == FieldDecl::ISK_CapturedVLAType) {
+    Record.push_back(D->InitStorage.getInt() + 1);
     Writer.AddTypeRef(
-        QualType(static_cast<Type *>(D->InitializerOrBitWidth.getPointer()), 0),
+        QualType(static_cast<Type *>(D->InitStorage.getPointer()), 0),
         Record);
   } else {
-    Record.push_back(0);
+    Record.push_back(D->InitStorage.getInt() + 1);
+    Writer.AddStmt(static_cast<Expr *>(D->InitStorage.getPointer()));
   }
   if (!D->getDeclName())
     Writer.AddDeclRef(Context.getInstantiatedFromUnnamedFieldDecl(D), Record);