================
@@ -0,0 +1,584 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fexperimental-late-parse-attributes -fsyntax-only -verify
%s
+
+#define __counted_by(f) __attribute__((counted_by(f)))
+
+//
=============================================================================
+// # Struct incomplete type with attribute in the decl position
+//
=============================================================================
+
+// Note: This could be considered misleading. The typedef isn't actually on
this
+// line. Also note the discrepancy in diagnostic count (27 vs 51) is due to
+// the pointer arithmetic on incomplete pointee type diagnostic always using
+// diagnostic text that refers to the underlying forward decl, even when the
+// typedef is used.
+// expected-note@+1 27{{forward declaration of 'Incomplete_t' (aka 'struct
IncompleteTy')}}
+struct IncompleteTy; // expected-note 51{{forward declaration of 'struct
IncompleteTy'}}
+
+typedef struct IncompleteTy Incomplete_t;
+
+struct CBBufDeclPos {
+ int count;
+ struct IncompleteTy* buf __counted_by(count); // OK expected-note
27{{__counted_by attribute is here}}
+ Incomplete_t* buf_typedef __counted_by(count); // OK expected-note
27{{__counted_by attribute is here}}
+};
+
+void consume_struct_IncompleteTy(struct IncompleteTy* buf);
+
+int idx(void);
+
+
+
+void test_CBBufDeclPos(struct CBBufDeclPos* ptr) {
+ //
===========================================================================
+ // ## Local variable initialization
+ //
===========================================================================
+ struct CBBufDeclPos explicit_desig_init = {
+ .count = 0,
+ // expected-error@+1{{cannot initialize 'CBBufDeclPos::buf' that has type
'struct IncompleteTy * __counted_by(count)' (aka 'struct IncompleteTy *')
because the pointee type 'struct IncompleteTy' is incomplete and the
'__counted_by' attribute requires the pointee type be complete when
initializing; consider providing a complete definition for 'struct
IncompleteTy' or using the '__sized_by' attribute}}
+ .buf = 0x0,
+ // expected-error@+1{{cannot initialize 'CBBufDeclPos::buf_typedef' that
has type 'Incomplete_t * __counted_by(count)' (aka 'struct IncompleteTy *')
because the pointee type 'Incomplete_t' (aka 'struct IncompleteTy') is
incomplete and the '__counted_by' attribute requires the pointee type be
complete when initializing; consider providing a complete definition for
'Incomplete_t' or using the '__sized_by' attribute}}
+ .buf_typedef = 0x0
+ };
+ // Variable is not currently marked as invalid so uses of the variable allows
+ // diagnostics to fire.
+ // expected-error@+1{{cannot assign to 'CBBufDeclPos::buf' that has type
'struct IncompleteTy * __counted_by(count)' (aka 'struct IncompleteTy *')
because the pointee type 'struct IncompleteTy' is incomplete and the
'__counted_by' attribute requires the pointee type be complete when assigning;
consider providing a complete definition for 'struct IncompleteTy' or using the
'__sized_by' attribute}}
+ explicit_desig_init.buf = 0x0;
+ // expected-error@+1{{cannot assign to 'CBBufDeclPos::buf_typedef' that has
type 'Incomplete_t * __counted_by(count)' (aka 'struct IncompleteTy *') because
the pointee type 'Incomplete_t' (aka 'struct IncompleteTy') is incomplete and
the '__counted_by' attribute requires the pointee type be complete when
assigning; consider providing a complete definition for 'Incomplete_t' or using
the '__sized_by' attribute}}
+ explicit_desig_init.buf_typedef = 0x0;
+ // expected-error@+1{{cannot use 'explicit_desig_init.buf' with type 'struct
IncompleteTy * __counted_by(count)' (aka 'struct IncompleteTy *') because the
pointee type 'struct IncompleteTy' is incomplete and the '__counted_by'
attribute requires the pointee type be complete in this context; consider
providing a complete definition for 'struct IncompleteTy' or using the
'__sized_by' attribute}}
+ void *tmp = explicit_desig_init.buf;
+ // expected-error@+1{{cannot use 'explicit_desig_init.buf_typedef' with type
'Incomplete_t * __counted_by(count)' (aka 'struct IncompleteTy *') because the
pointee type 'Incomplete_t' (aka 'struct IncompleteTy') is incomplete and the
'__counted_by' attribute requires the pointee type be complete in this context;
consider providing a complete definition for 'Incomplete_t' or using the
'__sized_by' attribute}}
----------------
delcypher wrote:
Ideally I think the all the information necessary for understanding an error
should be contained within the `error` diagnostic itself and additional useful
(but not strictly necessary) information can (but doesn't necessarily have to
be) put into notes.
What is necessary is a little subjective but...
> ‘Access to bounds-checked field has incomplete type’
doesn't contains all the necessary information IMHO and is vague enough that I
think it will cause more confusion than the current diagnostic text.
* These fields are only bounds checked with `-fbounds-safety`. Without
`-fbounds-safety` the attributes are just hints for
`__builtin_dynamic_object_size`. So calling the field bounds checked isn't
accurate unless `-fbound-safety` is on. Even then this is vague enough that
someone might not understand this is related to `-fbounds-safety`.
* It's not really obvious what "bounds-checked" field means (given we have
multiple implementations of bounds checking in clang) and more information is
**neccessary** to understand that this restriction comes from the
`__counted_by` attribute . I don't think this **necessary** information should
be moved into a note.
I'll grant you the diagnostic text is long but I believe almost everything
there is **necessary** to understand the error. However, the `'; consider
providing...` text isn't strictly necessary and could be moved to a note.
So I'd prefer to either leave the diagnostic text as it is, or move the `;
consider...` part of the text to its own note.
Please let me know what you'd prefer.
https://github.com/llvm/llvm-project/pull/106321
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