https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118367
Bug ID: 118367
Summary: Confusing error message with user generated
static_assert "expression cannot be used as a
function"
Product: gcc
Version: 14.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: veeloxfire at gmail dot com
Target Milestone: ---
The user-generated static assert messages output a confusing error message if
`data` and `size` are not functions
`
#include <cstddef>
struct A {
const char* data;
std::size_t size;
};
static_assert(false, A{});
`
produces the output
`
<source>:8:26: error: expression cannot be used as a function
8 | static_assert(false, A{});
|
`
https://godbolt.org/z/s8Gsaxa1T
This is because in `cexpr_str::type_check` the code does
`
message_sz = finish_call_expr (message_sz, &size_args, false, false,
complain);
message_data = finish_call_expr (message_data, &data_args, false, false,
complain);
if (message_sz == error_mark_node || message_data == error_mark_node)
return false;
`
https://gcc.gnu.org/git?p=gcc.git;a=blob;f=gcc/cp/semantics.cc;h=15840e10620cfcdc14bd03f5092b22e1864f4c06;hb=HEAD#l12129
Whereas in the other 3/4 cases a custom error messages inserted after something
fails, making the error more comprehensible.
Its not the end of the world but would potentially be a nice fix (it lead me
astray of the actual problem when experimenting)
I would do it myself but I've never contributed to gcc before so thought I
would just leave as a bug report
