From: Carlos O'Donell via Libc-alpha <libc-alpha@sourceware.org>
To: Sergei Trofimovich <slyfox@gentoo.org>, libc-alpha@sourceware.org
Subject: Re: [PATCH] configure.ac: fix include header discovery on gcc-12 [BZ #28183]
Date: Sat, 4 Feb 2023 18:46:25 -0500 [thread overview]
Message-ID: <3f53d014-9788-d773-8bb4-e87b013e1e10@redhat.com> (raw)
In-Reply-To: <20210804103739.2755644-1-slyfox@gentoo.org>
On 8/4/21 06:37, Sergei Trofimovich via Libc-alpha wrote:
> In https://gcc.gnu.org/PR101305 gcc introduced ABI-specific
> internal `include` include directory:
>
> gcc-12:
> /usr/lib/gcc/x86_64-pc-linux-gnu/12.0.0/32/include
> /usr/lib/gcc/x86_64-pc-linux-gnu/12.0.0/include
> gcc-11:
> /usr/lib/gcc/x86_64-pc-linux-gnu/11.2.0/include
This patch is technically correct IMO, but as-of today there isn't anything
in that path that actually impacts a glibc build with gcc 12.
I cannot reproduce the error that you quote below and I've tried a variety
of configurations using Fedora gcc 12.
I would accept this patch for master, but it needs a rebase and I will
review and ACK the rebase because I agree that from first-principles we may
want that extra path in the future.
Please rebase and post and TO me.
>
> glibc's build system tries to extract only one of them and fails
> the build for 32-bit ABI on x86_64:
>
> ../glibc/configure \
> --prefix=/usr \
> --build=x86_64-pc-linux-gnu \
> --host=i686-pc-linux-gnu \
> --with-headers=/usr/include \
> CC='x86_64-pc-linux-gnu-gcc -m32' \
> CXX='x86_64-pc-linux-gnu-g++ -m32' &&
> make
>
> python3 -B ../scripts/gen-as-const.py ...
> <stdin>:1:10: fatal error: stddef.h: No such file or directory
>
> To workaround the failure we extend `configure.ac` to also
> lookup `stddef.h` include directory and add it as a lower priority
> search path.
>
> Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
> ---
> configure | 37 ++++++++++++++++++++++++++++++++++---
> configure.ac | 15 ++++++++++++---
> 2 files changed, 46 insertions(+), 6 deletions(-)
>
> diff --git a/configure b/configure
> index 9619c10991..cac124f346 100755
> --- a/configure
> +++ b/configure
> @@ -5452,15 +5452,46 @@ $as_echo "$as_me: WARNING:
> *** some features or tests will be disabled.
> *** Check the INSTALL file for required versions." >&2;}
>
> -# if using special system headers, find out the compiler's sekrit
> -# header directory and add that to the list. NOTE: Only does the right
> -# thing on a system that doesn't need fixincludes. (Not presently a problem.)
> +# If using special system headers, find out the compiler's internal
> +# header directory and add that to the list to negate -nostdinc effect.
> +# NOTE: Only does the right thing on a system that doesn't need fixincludes.
> +# (Not presently a problem.)
> +# NOTE: sometimes 'include' is also present in gcc's ABI-specific paths
> +# like in https://sourceware.org/PR28183. To avoid it we probe a known
> +# 'stddef.h' header that resides in a common include directory.
> if test -n "$sysheaders"; then
> SYSINCLUDES=-nostdinc
> for d in include include-fixed; do
> i=`$CC -print-file-name="$d"` && test "x$i" != x && test "x$i" != "x$d" &&
> SYSINCLUDES="$SYSINCLUDES -isystem $i"
> done
> + for f in include/stddef.h; do
> + i=`$CC -print-file-name="$f"` && test "x$i" != x && test "x$i" != "x$f" &&
> + d=`$as_dirname -- "$i" ||
> +$as_expr X"$i" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
> + X"$i" : 'X\(//\)[^/]' \| \
> + X"$i" : 'X\(//\)$' \| \
> + X"$i" : 'X\(/\)' \| . 2>/dev/null ||
> +$as_echo X"$i" |
> + sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
> + s//\1/
> + q
> + }
> + /^X\(\/\/\)[^/].*/{
> + s//\1/
> + q
> + }
> + /^X\(\/\/\)$/{
> + s//\1/
> + q
> + }
> + /^X\(\/\).*/{
> + s//\1/
> + q
> + }
> + s/.*/./; q'` &&
> + SYSINCLUDES="$SYSINCLUDES -isystem $d"
> + done
> SYSINCLUDES="$SYSINCLUDES \
> -isystem `echo $sysheaders | sed 's/:/ -isystem /g'`"
> if test -n "$CXX"; then
> diff --git a/configure.ac b/configure.ac
> index 34ecbba540..9507a552ff 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -1083,15 +1083,24 @@ test -n "$aux_missing" && AC_MSG_WARN([
> *** some features or tests will be disabled.
> *** Check the INSTALL file for required versions.])
>
> -# if using special system headers, find out the compiler's sekrit
> -# header directory and add that to the list. NOTE: Only does the right
> -# thing on a system that doesn't need fixincludes. (Not presently a problem.)
> +# If using special system headers, find out the compiler's internal
> +# header directory and add that to the list to negate -nostdinc effect.
> +# NOTE: Only does the right thing on a system that doesn't need fixincludes.
> +# (Not presently a problem.)
> +# NOTE: sometimes 'include' is also present in gcc's ABI-specific paths
> +# like in https://sourceware.org/PR28183. To avoid it we probe a known
> +# 'stddef.h' header that resides in a common include directory.
> if test -n "$sysheaders"; then
> SYSINCLUDES=-nostdinc
> for d in include include-fixed; do
> i=`$CC -print-file-name="$d"` && test "x$i" != x && test "x$i" != "x$d" &&
> SYSINCLUDES="$SYSINCLUDES -isystem $i"
> done
> + for f in include/stddef.h; do
> + i=`$CC -print-file-name="$f"` && test "x$i" != x && test "x$i" != "x$f" &&
> + d=`AS_DIRNAME(["$i"])` &&
> + SYSINCLUDES="$SYSINCLUDES -isystem $d"
> + done
> SYSINCLUDES="$SYSINCLUDES \
> -isystem `echo $sysheaders | sed 's/:/ -isystem /g'`"
> if test -n "$CXX"; then
--
Cheers,
Carlos.
prev parent reply other threads:[~2023-02-04 23:46 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-04 10:37 [PATCH] configure.ac: fix include header discovery on gcc-12 [BZ #28183] Sergei Trofimovich via Libc-alpha
2021-08-16 18:15 ` Sergei Trofimovich via Libc-alpha
2023-02-04 23:46 ` Carlos O'Donell via Libc-alpha [this message]
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