https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103996
Bug ID: 103996
Summary: Enhancement: Better diagnostic for invalid reuse of a
function name
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: nightstrike at gmail dot com
Target Milestone: ---
Related email thread:
https://gcc.gnu.org/pipermail/gcc-help/2022-January/141117.html
I recently hit this problem:
#include <strings.h>
void f() {
index[0] = 0;
}
#gcc is 11.2.0
gcc -c a.c
a.c:4:7: error: subscripted value is neither array nor pointer nor vector
4 | index[1] = 0;
| ^
I could not find a compiler option that would tell me what the root cause was.
I wasn't getting a simple "undeclared" error, so I surmised the name must
already be in use, but I was confused as to how or where it was being used. My
first thought was that maybe index was a global variable, so I tried using
-Wshadow. Eventually, I found that it was a function from strings.h which was
included several layers down an include spiral.
I think an effective note from gcc such as "index was previously declared here
as a function", or something similar that often happens in other diagnostics,
would aid in finding the root cause of my bug.
Incidentally, in my actual scenario, the real bug was that I forgot to access
index as a member of a struct: x.index vs index. But I'd wager that expecting
GCC to look for all nearby structs for a similarly named member is
unreasonable. Simply telling me where index originates, though, would have
helped greatly.
