https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89052
Bug ID: 89052
Summary: excessive data segment size causes a hang
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
Making a silly mistake and using the wrong macro such as SIZE_MAX instead of
MAX_SIZE as the array size when defining a global object seems to cause as to
hang presumably while trying to allocate huge amounts of memory. It's not
immediately obvious what the problem might be in such a case.
GCC already warns when the size of any single object exceeds some maximum but
it could help prevent this kind of a mistake by computing the size of all
global objects (or even the size of local objects in each function) and issuing
a warning such as -Wlarger-than= or even an error when the total size of all of
them exceeds the same limit. The current permissive limit is PTRDIFF_MAX but I
don't think there are too many 64-bit systems that can actually handle that
much memory so using a lower limit lower would be even better.
$ (cat a.c && ulimit -v 10000 && gcc -Wall -c a.c)
#include <stdint.h>
#define MAX_SIZE 32
char a[SIZE_MAX / 2] = "1"; // typo: should have been MAX_SIZE / 2
char b[SIZE_MAX / 2] = "x"; // ditto
xgcc: internal compiler error: Segmentation fault signal terminated program cc1
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See <https://gcc.gnu.org/bugs/> for instructions.
