[PATCH] D76087: [Sema][SVE] Reject sizeless types in exception specs

[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 project: clang.
rsandifo-arm added a parent revision: D76086: [Sema][SVE] Reject arithmetic on pointers to sizeless types.

The same rules for throwing and catching incomplete types also
apply to sizeless types.  This patch enforces that for explicit
exception specs.

(In practice, throwing pointers to sizeless types could probably
be handled without problems.  It would be an odd thing to do though,
and so it didn't seem worth treating as a special case.)


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D76087

Files:
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/lib/Sema/SemaExceptionSpec.cpp
  clang/test/SemaCXX/sizeless-1.cpp


Index: clang/test/SemaCXX/sizeless-1.cpp
===================================================================
--- clang/test/SemaCXX/sizeless-1.cpp
+++ clang/test/SemaCXX/sizeless-1.cpp
@@ -345,6 +345,12 @@
 constexpr int ce_taking_int8(svint8_t) { return 1; } // expected-error {{constexpr function's 1st parameter type 'svint8_t' (aka '__SVInt8_t') is not a literal type}}
 #endif
 
+#if __cplusplus < 201703L
+void throwing_func() throw(svint8_t);             // expected-error {{sizeless type 'svint8_t' (aka '__SVInt8_t') is not allowed in exception specification}}
+void throwing_pointer_func() throw(svint8_t *);   // expected-error {{pointer to sizeless type 'svint8_t' (aka '__SVInt8_t') is not allowed in exception specification}}
+void throwing_reference_func() throw(svint8_t &); // expected-error {{reference to sizeless type 'svint8_t' (aka '__SVInt8_t') is not allowed in exception specification}}
+#endif
+
 template <typename T>
 void template_fn_direct(T) {}
 template <typename T>
Index: clang/lib/Sema/SemaExceptionSpec.cpp
===================================================================
--- clang/lib/Sema/SemaExceptionSpec.cpp
+++ clang/lib/Sema/SemaExceptionSpec.cpp
@@ -167,6 +167,14 @@
       RequireCompleteType(Range.getBegin(), PointeeT, DiagID, Kind, Range))
     return ReturnValueOnError;
 
+  // The MSVC compatibility mode doesn't extend to sizeless types,
+  // so diagnose them separately.
+  if (PointeeT->isSizelessType()) {
+    Diag(Range.getBegin(), diag::err_sizeless_in_exception_spec)
+        << Kind << PointeeT << Range;
+    return true;
+  }
+
   return false;
 }
 
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1534,6 +1534,9 @@
 def err_incomplete_in_exception_spec : Error<
   "%select{|pointer to |reference to }0incomplete type %1 is not allowed "
   "in exception specification">;
+def err_sizeless_in_exception_spec : Error<
+  "%select{|pointer to |reference to }0sizeless type %1 is not allowed "
+  "in exception specification">;
 def ext_incomplete_in_exception_spec : ExtWarn<err_incomplete_in_exception_spec.Text>,
   InGroup<MicrosoftExceptionSpec>;
 def err_rref_in_exception_spec : Error<


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