https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117861
Bug ID: 117861
Summary: pragma Suppress (Overflow_check) is ignored and
overflow fails at compilation rather than throwing an
exception
Product: gcc
Version: 14.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ada
Assignee: unassigned at gcc dot gnu.org
Reporter: 00120260a at gmail dot com
CC: dkm at gcc dot gnu.org
Target Milestone: ---
+===========================GNAT BUG DETECTED==============================+
| 14.2.0 (x86_64-pc-linux-gnu) GCC error: |
| in gnat_to_gnu, at ada/gcc-interface/trans.cc:6333 |
| Error detected at increment_integer.adb:6:29 |
| Compiling increment_integer.adb |
| Please submit a bug report; see https://gcc.gnu.org/bugs/ . |
| Use a subject line meaningful to you and us to track the bug. |
| Include the entire contents of this bug box in the report. |
| Include the exact command that you entered. |
| Also include sources listed below. |
+==========================================================================+
> procedure Increment_integer (I: in out Integer) is
> A: Integer := Integer'Last;
> pragma suppress (Overflow_Check, A);
> pragma suppress (Range_Check, A);
> begin
> A := Integer'Succ (A);
> end Increment_integer;
It's to showcase a need I have a variable that risks causing an overflow (of
its subtype or base type) at the end of a loop that fills an array, but only at
the last iteration so it doesn't matter, and only in case the array's last
index equals the index's base type last possible value.
While a table is unlikely to have Positive'Last as an index, it could be
indexed with Boolean, so the last iteration of the loop WILL necessarily causes
overflow. It should normally trigger a Constraint_Error, that I can catch, but
I want to suppress the check instead. But `A := Integer'Succ (A);` is straight
up refused.
