[PATCH] D76694: [Sema][SVE] Allow casting SVE types to themselves in C

[Richard Sandiford via Phabricator via cfe-commits]

rsandifo-arm created this revision.
rsandifo-arm added reviewers: sdesmalen, efriedma, rovka, rjmccall.
Herald added subscribers: cfe-commits, psnobl, rkruppe, tschuett.
Herald added a reviewer: rengolin.
Herald added a project: clang.

Casts from an SVE type to itself aren't very useful, but they are
supposed to be valid, and could occur in things like macro expansions.

Such casts already work for C++ and are tested by sizeless-1.cpp.
This patch makes them work for C too.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D76694

Files:
  clang/lib/Sema/SemaCast.cpp
  clang/test/Sema/sizeless-1.c


Index: clang/test/Sema/sizeless-1.c
===================================================================
--- clang/test/Sema/sizeless-1.c
+++ clang/test/Sema/sizeless-1.c
@@ -113,6 +113,8 @@
 
   sel = local_int8; // expected-error {{assigning to 'int' from incompatible type 'svint8_t'}}
 
+  local_int8 = (svint8_t)local_int8;
+  local_int8 = (const svint8_t)local_int8;
   local_int8 = (svint8_t)local_int16; // expected-error {{used type 'svint8_t' (aka '__SVInt8_t') where arithmetic or pointer type is required}}
   local_int8 = (svint8_t)0;           // expected-error {{used type 'svint8_t' (aka '__SVInt8_t') where arithmetic or pointer type is required}}
   sel = (int)local_int8;              // expected-error {{operand of type 'svint8_t' (aka '__SVInt8_t') where arithmetic or pointer type is required}}
Index: clang/lib/Sema/SemaCast.cpp
===================================================================
--- clang/lib/Sema/SemaCast.cpp
+++ clang/lib/Sema/SemaCast.cpp
@@ -2652,6 +2652,13 @@
     return;
   }
 
+  // Allow casting a sizeless built-in type to itself.
+  if (DestType->isSizelessBuiltinType() &&
+      Self.Context.hasSameUnqualifiedType(DestType, SrcType)) {
+    Kind = CK_NoOp;
+    return;
+  }
+
   if (!DestType->isScalarType() && !DestType->isVectorType()) {
     const RecordType *DestRecordTy = DestType->getAs<RecordType>();
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D76694.252275.patch
Type: text/x-patch
Size: 1368 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20200324/3342c4d6/attachment-0001.bin>