[clang] [BoundsSafety] build TypeLoc for CountAttributedType (PR #167287)

[Henrik G. Olsson via cfe-commits]

================
@@ -253,20 +319,36 @@ static void EmitIncompleteCountedByPointeeNotes(Sema &S,
         << CATy->getPointeeType();
   }
 
-  // Suggest using __sized_by(_or_null) instead of __counted_by(_or_null) as
-  // __sized_by(_or_null) doesn't have the complete type restriction.
-  //
-  // We use the source range of the expression on the CountAttributedType as an
-  // approximation for the source range of the attribute. This isn't quite right
-  // but isn't easy to fix right now.
-  //
-  // TODO: Implement logic to find the relevant TypeLoc for the attribute and
-  // get the SourceRange from that (#113582).
-  //
-  // TODO: We should emit a fix-it here.
-  SourceRange AttrSrcRange = CATy->getCountExpr()->getSourceRange();
+  CountAttributedTypeLoc CATL;
+  if (!TL.isNull())
+    CATL = TL.getAs<CountAttributedTypeLoc>();
+
+  if (CATL.isNull()) {
+    // Fall back to pointing to the count expr - not great, but close enough.
+    // This should happen rarely, if ever.
+    S.Diag(CATy->getCountExpr()->getExprLoc(),
+           diag::note_counted_by_consider_using_sized_by)
+        << CATy->isOrNull();
+    return;
+  }
+  SourceRange AttrSrcRange = CATL.getAttrNameRange(S);
+
+  StringRef Spelling = CATL.getAttrNameAsWritten(S);
+  StringRef FixedSpelling;
+  if (Spelling == "__counted_by")
+    FixedSpelling = "__sized_by";
+  else if (Spelling == "counted_by")
+    FixedSpelling = "sized_by";
+  else if (Spelling == "__counted_by_or_null")
+    FixedSpelling = "__sized_by_or_null";
+  else if (Spelling == "counted_by_or_null")
+    FixedSpelling = "sized_by_or_null";
----------------
hnrklssn wrote:

done!

https://github.com/llvm/llvm-project/pull/167287