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author | Tom Lane <tgl@sss.pgh.pa.us> | 2022-02-17 22:45:34 -0500 |
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committer | Tom Lane <tgl@sss.pgh.pa.us> | 2022-02-17 22:46:01 -0500 |
commit | de447bb8e6fbbad19f964a2d7f04c9ccc1d06903 (patch) | |
tree | 95aad2cc5e0c44e8d3e1fb64dfa369772715b3c0 /config/c-compiler.m4 | |
parent | f927a6ec3ef710ad2bd7d9c63f524b7a22d7e664 (diff) | |
download | postgresql-de447bb8e6fbbad19f964a2d7f04c9ccc1d06903.tar.gz |
Suppress warning about stack_base_ptr with late-model GCC.
GCC 12 complains that set_stack_base is storing the address of
a local variable in a long-lived pointer. This is an entirely
reasonable warning (indeed, it just helped us find a bug);
but that behavior is intentional here. We can work around it
by using __builtin_frame_address(0) instead of a specific local
variable; that produces an address a dozen or so bytes different,
in my testing, but we don't care about such a small difference.
Maybe someday a compiler lacking that function will start to issue
a similar warning, but we'll worry about that when it happens.
Patch by me, per a suggestion from Andres Freund. Back-patch to
v12, which is as far back as the patch will go without some pain.
(Recently-established project policy would permit a back-patch as
far as 9.2, but I'm disinclined to expend the work until GCC 12
is much more widespread.)
Discussion: https://postgr.es/m/3773792.1645141467@sss.pgh.pa.us
Diffstat (limited to 'config/c-compiler.m4')
-rw-r--r-- | config/c-compiler.m4 | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/config/c-compiler.m4 b/config/c-compiler.m4 index 780e906ecc..d3562d6fee 100644 --- a/config/c-compiler.m4 +++ b/config/c-compiler.m4 @@ -381,6 +381,28 @@ fi])# PGAC_CHECK_BUILTIN_FUNC +# PGAC_CHECK_BUILTIN_FUNC_PTR +# ----------------------- +# Like PGAC_CHECK_BUILTIN_FUNC, except that the function is assumed to +# return a pointer type, and the argument(s) should be given literally. +# This handles some cases that PGAC_CHECK_BUILTIN_FUNC doesn't. +AC_DEFUN([PGAC_CHECK_BUILTIN_FUNC_PTR], +[AC_CACHE_CHECK(for $1, pgac_cv$1, +[AC_LINK_IFELSE([AC_LANG_PROGRAM([ +void * +call$1(void) +{ + return $1($2); +}], [])], +[pgac_cv$1=yes], +[pgac_cv$1=no])]) +if test x"${pgac_cv$1}" = xyes ; then +AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE$1]), 1, + [Define to 1 if your compiler understands $1.]) +fi])# PGAC_CHECK_BUILTIN_FUNC_PTR + + + # PGAC_PROG_VARCC_VARFLAGS_OPT # ---------------------------- # Given a compiler, variable name and a string, check if the compiler |