https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91463
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Component|c |middle-end
Resolution|--- |FIXED
Target Milestone|--- |10.0
--- Comment #7 from Martin Sebor <msebor at gcc dot gnu.org> ---
GCC 10 now issues the following warning for the test case in comment #0:
pr91463.c: In function ‘f’:
pr91463.c:7:6: warning: array subscript 666 is above array bounds of ‘int[0]’
[-Warray-bounds]
7 | s.a[666] = 0; // missing -Warray-bounds
| ~~~^~~~~
pr91463.c:1:19: note: while referencing ‘a’
1 | struct S { int n, a[]; };
| ^
pr91463.c:3:10: note: defined here ‘s’
3 | struct S s = { 2, { 1, 0 } };
| ^
I agree that some of these problems can be detected earlier. It might be worth
moving some of the -Warray-bounds code out of tree-vrp.c and into some utility
function that could be called by earlier passes, or even by the front-ends
without optimization, to detect the basic problems. I'll keep that in mind as
a possible future project.
