Use descriptive message if list initializer is incorrectly parenthesized.

If initializer contains parentheses around braced list where it is not allowed,
as in construct int({0}), clang issued message like `functional-style cast
from 'void' to 'int' is not allowed`, which does not help much. Both gcc and
msvc issue message `list-initializer for non-class type must not be
parenthesized`, which is more descriptive. This change implements similar
message for clang.

Differential Revision: https://reviews.llvm.org/D25816

llvm-svn: 286721

1 files changed, 24 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 634954c3e85..a87d5efaf08 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -1221,6 +1221,17 @@ Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep,
   if (!TInfo)
     TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation());
 
+  // Handle errors like: int({0})
+  if (exprs.size() == 1 && !canInitializeWithParenthesizedList(Ty) &&
+      LParenLoc.isValid() && RParenLoc.isValid())
+    if (auto IList = dyn_cast<InitListExpr>(exprs[0])) {
+      Diag(TInfo->getTypeLoc().getLocStart(), diag::err_list_init_in_parens)
+          << Ty << IList->getSourceRange()
+          << FixItHint::CreateRemoval(LParenLoc)
+          << FixItHint::CreateRemoval(RParenLoc);
+      LParenLoc = RParenLoc = SourceLocation();
+    }
+
   auto Result = BuildCXXTypeConstructExpr(TInfo, LParenLoc, exprs, RParenLoc);
   // Avoid creating a non-type-dependent expression that contains typos.
   // Non-type-dependent expressions are liable to be discarded without
@@ -1562,8 +1573,20 @@ Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
     return ExprError();
 
   SourceRange DirectInitRange;
-  if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer))
+  if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) {
     DirectInitRange = List->getSourceRange();
+    // Handle errors like: new int a({0})
+    if (List->getNumExprs() == 1 &&
+        !canInitializeWithParenthesizedList(AllocType))
+      if (auto IList = dyn_cast<InitListExpr>(List->getExpr(0))) {
+        Diag(TInfo->getTypeLoc().getLocStart(), diag::err_list_init_in_parens)
+            << AllocType << List->getSourceRange()
+            << FixItHint::CreateRemoval(List->getLocStart())
+            << FixItHint::CreateRemoval(List->getLocEnd());
+        DirectInitRange = SourceRange();
+        Initializer = IList;
+      }
+  }
 
   return BuildCXXNew(SourceRange(StartLoc, D.getLocEnd()), UseGlobal,
                      PlacementLParen,