[cfe-commits] [Patch] Produce errors for 'static' and type qualifiers in array declarators

[John McCall]

On Aug 10, 2012, at 2:27 AM, Hans Wennborg wrote:
> On Mon, Aug 6, 2012 at 7:47 PM, Eli Friedman <eli.friedman at gmail.com> wrote:
>> +      if (chunkIndex > 0) {
>> +        const DeclaratorChunk &NextChunk = D.getTypeObject(chunkIndex - 1);
>> +        if (NextChunk.Kind == DeclaratorChunk::Array) {
>> 
>> This looks suspect: I think you need to trigger this error in more
>> cases.  Consider, for example, "void f(int (*x)[static 10]);".  Take a
>> look at checkQualifiedFunction.
> 
> Ah, thanks for pointing that out. Attaching a new attempt.

+        unsigned x = chunkIndex;
+        for (;;) {
+          // Walk outwards along the declarator chunks.
+          if (x == 0)
+            break;
+          x--;

This can just be
  while (x != 0) {
    x--; 
You could also use (x-- != 0), but I'll leave that choice up to you.

+          const DeclaratorChunk &DC = D.getTypeObject(x);
+
+          switch (DC.Kind) {
+          case DeclaratorChunk::Paren:
+            continue;
+          case DeclaratorChunk::Array:
+          case DeclaratorChunk::Pointer:

We try to avoid 'default' cases, and this is a good example why.  I claim
that there are no declarator chunks which are actually valid here except
Paren.  Suppressing the error when the chunk is a Function or BlockPointer
is fine, since we'll still get the more-important diagnostic that the type is
invalid.  We should not suppress the error when the chunk is Reference
or MemberPointer, though.  Also, if someone adds a new declarator chunk
(not entirely impossible), they should have to consider what to do in this
case.

John.