https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120657
Bug ID: 120657
Summary: Improve diagnostic for conditional operators that
create the invalid type restrict void
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: luigighiron at gmail dot com
Target Milestone: ---
Here are two programs that both incorrectly use a conditional operator, and
their error messages generated by GCC (<source> is the name of the file on
godbolt).
Program 1:
int main(void){
void*p=0;
int*restrict*q=0;
typedef typeof(1?p:q)T;
}
Error 1:
<source>:4:5: error: invalid use of 'restrict'
4 | typedef typeof(1?p:q)T;
| ^~~~~~~
Program 2:
int main(void){
float*p=0;
int*restrict*q=0;
typedef typeof(1?p:q)T;
}
Error 2:
<source>:4:23: error: pointer type mismatch in conditional expression
[-Wincompatible-pointer-types]
4 | typedef typeof(1?p:q)T;
| ^
<source>:4:22: note: first expression has type 'float *'
4 | typedef typeof(1?p:q)T;
| ^
<source>:4:24: note: second expression has type 'int * restrict*'
4 | typedef typeof(1?p:q)T;
| ^
In error 2 the colon of the conditional expression is pointed to, and the type
of the operands are pointed out to help clarify the issue. However, in error 1
it just says restrict is used incorrectly and points to the first token on the
same line as the closing parenthesis. I think it is worth improving the error
message of program 1 to indicate that the conditional expression is causing the
error.
