https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69972
Bug ID: 69972
Summary: duplicate integer overflow diagnostic in constant
expressions
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
Both the C and the C++ front ends issue duplicate diagnostics for integer
overflows in constant expressions. For example, in C:
$ /home/msebor/build/gcc-4.9.3/gcc/xgcc -B/home/msebor/build/gcc-4.9.3/gcc -S
-Wall -Wextra -Wpedantic -o/dev/null -xc x.c
x.c:1:24: warning: integer overflow in expression [-Woverflow]
enum { e = __INT_MAX__ + 1 };
^
x.c:1:8: warning: overflow in constant expression [-Woverflow]
enum { e = __INT_MAX__ + 1 };
^
G++ issues two similar kinds of diagnostics for the following code, one
-Woverflow and another -fpermissive:
$ cat t.c && /build/gcc-trunk/gcc/xgcc -B /build/gcc-trunk/gcc -S -Wall -Wextra
-Wpedantic -o/dev/null -xc++ t.c
template <int N> struct S { };
S<(__INT_MAX__ + 1)> s;
t.c:2:16: warning: integer overflow in expression [-Woverflow]
S<(__INT_MAX__ + 1)> s;
~~~~~~~~~~~~^~~
t.c:2:20: error: overflow in constant expression [-fpermissive]
S<(__INT_MAX__ + 1)> s;
^
t.c:2:20: note: in template argument for type ‘int’
