> On Feb 5, 2021, at 9:51 AM, Todd C. Miller <Todd.Miller@sudo.ws> =
wrote:
>=20
> On Fri, 05 Feb 2021 15:42:28 +0100, =3D?utf-8?Q?S=3DC3=3DA9bastien?=3D =
Hinderer wrote:
>=20
>> It seems AC_PROG_CC wrongly believes clang is gcc and that may cause =
problems
>> when clang is passed a warning which is only supposrted by gcc, as is
>> the case e.g. for -Wno-stringop-truncation.
>=20
> clang also defines __GNUC__ and the related defines, which is why
> it is identified as gcc.
>=20
>> Is there a recommended way to determine for sure from a configure =
script
>> whether the detected C compiler is clang or gcc?

I would *discourage* trying to figure out if a C compiler is gcc or =
clang.
Instead, create separate detectors for whatever you=E2=80=99re looking =
for.

The gcc & clang groups coordinate with each other; they try to provide =
the same
flags & API for the same functionality, and occasionally copy from each =
other.
So trying to detect =E2=80=9Cdo this if GCC=E2=80=9D is generally wrong; =
clang may have that interface & functionality
when someone compiles the code.

--- David A. Wheeler