https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65258
Bug ID: 65258
Summary: Wrong array bounds warning
Product: gcc
Version: 4.9.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: myrusmailacc at ru dot ru
Created attachment 34907
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34907&action=edit
main.c
http://coliru.stacked-crooked.com/a/cd5820f0371106dd
At least gcc and g++ 4.8.2 and 4.9.2 are affected
Source:
#include <stdio.h>
int main(){
unsigned i, j, a[10] = {0};
for (j = 23; j < 25; j++){
for (i = j / 8; i --> 0;) a[i] = 0;
for (i = 1; i --> 0;) printf("%u", a[i]);
}
return 0;
}
Output:
gcc -O3 -Wall -Wextra -pedantic main.cpp && ./a.out
main.cpp: In function 'int main()':
main.cpp:7:38: warning: array subscript is above array bounds [-Warray-bounds]
for (i = j / 8; i --> 0;) a[i] = 0;
^
main.cpp:7:38: warning: array subscript is above array bounds [-Warray-bounds]
main.cpp:7:38: warning: array subscript is above array bounds [-Warray-bounds]
main.cpp:7:38: warning: array subscript is above array bounds [-Warray-bounds]
main.cpp:7:38: warning: array subscript is above array bounds [-Warray-bounds]
main.cpp:7:38: warning: array subscript is above array bounds [-Warray-bounds]
main.cpp:7:38: warning: array subscript is above array bounds [-Warray-bounds]
00
