https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93432
Bug ID: 93432
Summary: variable is used uninitialized, but gcc shows no
warning
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: sven.koehler at gmail dot com
Target Milestone: ---
Consider the following code:
int test53(int y) {
int z;
for (int x=0; x<10; x=x+1,y=y+1,z=z+1) {
if (y<10) {
continue;
}
z = 1;
}
return z;
}
int main() {
printf("%d\n", test53(0));
printf("%d\n", test53(5));
printf("%d\n", test53(10));
return 0;
}
If y < 10 in the first iteration, the variable z is used uninitialized.
Clearly, the continue can potentially skip the initialization of z.
Even if -Wall and -Wextra, gcc does not produce a warning.
