Parse bounds declarations for variable declarations.

lib/Parse/ParseDecl.cpp

@@ -1622,8 +1622,13 @@ bool Parser::MightBeDeclarator(unsigned Context) {
       // At namespace scope, 'identifier:' is probably a typo for 'identifier::'
       // and in block scope it's probably a label. Inside a class definition,
       // this is a bit-field.
+      //
+      // For Checked C 'identifier:' is a valid start to a declarator because
+      // it may be followed by a bounds expression declaring the bounds of
+      // identifier.
       return Context == Declarator::MemberContext ||
-             (getLangOpts().CPlusPlus && Context == Declarator::FileContext);
+             (getLangOpts().CPlusPlus && Context == Declarator::FileContext) ||
+             getLangOpts().CheckedC;
 
     case tok::identifier: // Possible virt-specifier.
       return getLangOpts().CPlusPlus11 && isCXX11VirtSpecifier(NextToken());
@@ -1936,6 +1941,8 @@ bool Parser::ParseAsmAttributesAfterDeclarator(Declarator &D) {
 /// [GNU]   declarator simple-asm-expr[opt] attributes[opt]
 /// [GNU]   declarator simple-asm-expr[opt] attributes[opt] '=' initializer
 /// [C++]   declarator initializer[opt]
+/// [Checked C] declarator ':' bounds-expression
+/// [Checked C] declarator ':' bounds-expression '=' initializer
 ///
 /// [C++] initializer:
 /// [C++]   '=' initializer-clause
@@ -2018,6 +2025,23 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
 
   bool TypeContainsAuto = D.getDeclSpec().containsPlaceholderType();
 
+  // Parse the optional Checked C bounds expression.
+  if (getLangOpts().CheckedC && Tok.is(tok::colon)) {
+    ConsumeToken();
+    ExprResult Bounds = ParseBoundsExpression();
+    if (Bounds.isInvalid())
+      SkipUntil(tok::comma, tok::equal, StopAtSemi | StopBeforeMatch);
+
+    VarDecl *ThisVarDecl = dyn_cast<VarDecl>(ThisDecl);
+    if (ThisVarDecl) {
+      if (Bounds.isInvalid())
+        Actions.ActOnInvalidBoundsExpr(ThisVarDecl);
+      else
+        Actions.ActOnBoundsExpr(ThisVarDecl, cast<BoundsExpr>(Bounds.get()));
+    } else
+      llvm_unreachable("Unexpected decl type");
+  }
+
   // Parse declarator '=' initializer.
   // If a '==' or '+=' is found, suggest a fixit to '='.
   if (isTokenEqualOrEqualTypo()) {

lib/Parse/ParseExpr.cpp

@@ -2794,20 +2794,20 @@ ExprResult Parser::ParseBoundsExpression() {
       // Look for e1 "," e2
       ExprResult LowerBound =
         Actions.CorrectDelayedTyposInExpr(ParseAssignmentExpression());
-      if (LowerBound.isInvalid())
-        Result = ExprError();
-      else if (ExpectAndConsume(tok::comma))
-        Result = ExprError();
-      else {
-        ExprResult UpperBound =
-          Actions.CorrectDelayedTyposInExpr(ParseAssignmentExpression());
-        if (UpperBound.isInvalid())
-          Result = ExprError();
-        else
-          Result = Actions.ActOnRangeBoundsExpr(BoundsKWLoc, LowerBound.get(),
-                                                UpperBound.get(),
-                                                Tok.getLocation());
-      }
+
+     if (ExpectAndConsume(tok::comma))
+       // We didn't find a comma, so don't try to parse the upper bounds expression.
+       Result = ExprError();
+     else {
+       ExprResult UpperBound =
+         Actions.CorrectDelayedTyposInExpr(ParseAssignmentExpression());
+       if (LowerBound.isInvalid() || UpperBound.isInvalid())
+         Result = ExprError();
+       else
+         Result = Actions.ActOnRangeBoundsExpr(BoundsKWLoc, LowerBound.get(),
+                                               UpperBound.get(),
+                                               Tok.getLocation());
+     }
     } // if (!FoundNullaryOperator)
   } else {
     // The identifier is not a valid contextual keyword for the start of a
@@ -2817,6 +2817,13 @@ ExprResult Parser::ParseBoundsExpression() {
     Result = ExprError();
   }
 
+  // Result could be invalid because of a syntax error or a semantic checking
+  // error.  We don't know which.  Skip tokens until a right paren is found.
+  // If this was only a semantic checking error, the input will already be at
+  // a right paren, so skipping will be do nothing.
+  if (Result.isInvalid())
+    SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch);
+
   PT.consumeClose();
   return Result;
 }