Add checking of redeclarations of variables with bounds.

include/clang/AST/Type.h

@@ -1713,6 +1713,7 @@ class Type : public ExtQualsTypeCommonBase {
   bool isDependentSizedArrayType() const;
   /// \brief whether this is a Checked C checked array type.
   bool isCheckedArrayType() const;
+  bool isUncheckedArrayType() const;
   bool isRecordType() const;
   bool isClassType() const;
   bool isStructureType() const;
@@ -5670,6 +5671,12 @@ inline bool Type::isCheckedArrayType() const {
   else
     return false;
 }
+inline bool Type::isUncheckedArrayType() const {
+  if (const ArrayType *T = dyn_cast<ArrayType>(CanonicalType))
+    return !T->isChecked();
+  else
+    return false;
+}
 inline bool Type::isBuiltinType() const {
   return isa<BuiltinType>(CanonicalType);
 }

include/clang/Basic/DiagnosticSemaKinds.td

@@ -8843,23 +8843,19 @@ def err_bounds_type_annotation_lost_checking : Error<
 
  def note_previous_bounds_decl : Note<"previous bounds declaration is here">;
 
- def err_conflicting_parameter_bounds : Error<
-   "function redeclaration has conflicting parameter bounds">;
-
- def err_conflicting_return_bounds : Error<
-   "function redeclaration has conflicting return bounds">;
-
-  def err_added_bounds_for_return : Error<
-    "function redeclaration added return bounds">;
-
-  def err_missing_bounds_for_return : Error <
-    "function redeclaration dropped return bounds">;
-
-  def err_added_bounds_for_parameter : Error<
-    "function redeclaration added bounds for parameter">;
-
-  def err_missing_bounds_for_parameter : Error<
-    "function redeclaration dropped bounds for parameter">;
+  def err_decl_conflicting_bounds : Error<
+    "%select{function redeclaration has conflicting parameter bounds|function "
+    "redeclaration has conflicting return bounds|variable redeclaration has "
+    "conflicting bounds}0">;
+
+  def err_decl_added_bounds : Error<
+    "%select{function redeclaration added bounds for parameter|function "
+    "redeclaration added return bounds|variable redeclaration added bounds}0">;
+
+  def err_decl_dropped_bounds : Error<
+    "%select{function redeclaration dropped bounds for parameter|function "
+    "redeclaration dropped return bounds|variable redeclaration dropped "
+    "bounds}0">;
 
   def err_conflicting_bounds : Error<"conflicting bounds for %0">;
 

include/clang/Sema/Sema.h

@@ -2267,6 +2267,14 @@ class Sema {
     CCT_Union
   };
 
+  // used for %select in diagnostics for errors involving redeclarations
+  // with bounds
+  enum class CheckedCBoundsError {
+    CCBE_Parameter,
+    CCBE_Return,
+    CCBE_Variable
+  };
+
   CheckedTypeClassification classifyForCheckedTypeDiagnostic(QualType qt);
 
   // AssignmentAction - This is used by all the assignment diagnostic functions

lib/Parse/ParseDecl.cpp

@@ -2086,22 +2086,24 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
 
   bool TypeContainsAuto = D.getDeclSpec().containsPlaceholderType();
 
-  // Parse the optional Checked C bounds expression or interop type
-  // annotation.
-  if (getLangOpts().CheckedC && Tok.is(tok::colon)) {
-    ConsumeToken();
-    ExprResult Bounds = ParseBoundsExpressionOrInteropType(D);
-    if (Bounds.isInvalid())
-      SkipUntil(tok::comma, tok::equal, StopAtSemi | StopBeforeMatch);
-
+  // If this is a variable declarator in Checked C, parse the bounds expression
+  // (if any) and set the bounds expression.  Function declarators are ignored
+  // here because return bounds expressions are parsed as part of function
+  // declarators already.
+  if (getLangOpts().CheckedC && isa<VarDecl>(ThisDecl)) {
     VarDecl *ThisVarDecl = dyn_cast<VarDecl>(ThisDecl);
-    if (ThisVarDecl) {
-      if (Bounds.isInvalid())
-        Actions.ActOnInvalidBoundsDecl(ThisVarDecl);
-      else
-        Actions.ActOnBoundsDecl(ThisVarDecl, cast<BoundsExpr>(Bounds.get()));
-    } else
-      llvm_unreachable("Unexpected decl type");
+    BoundsExpr *Bounds = nullptr;
+    // The optional Checked C bounds expression or interop type annotation.
+    if (Tok.is(tok::colon)) {
+      ConsumeToken();
+      ExprResult ParsedBounds = ParseBoundsExpressionOrInteropType(D);
+      if (ParsedBounds.isInvalid()) {
+        SkipUntil(tok::comma, tok::equal, StopAtSemi | StopBeforeMatch);
+        Bounds = Actions.CreateInvalidBoundsExpr();
+      } else
+        Bounds = cast<BoundsExpr>(ParsedBounds.get());
+    }
+    Actions.ActOnBoundsDecl(ThisVarDecl, Bounds);
   }
 
   // Parse declarator '=' initializer.