From 20debce9941edc07037a09231307b4a6d75d5258 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 14 Feb 2026 18:29:48 -0500 Subject: [PATCH v6 3/7] Various minor adjustments for AIX. Remove platform-specific adjustment of MEMSET_LOOP_LIMIT; maybe that's still the right thing, but it really ought to be re-tested. (Indeed we should reconsider MemSet altogether, but that's not a job for this patch set.) Prefer unnamed POSIX semaphores, rather than the default choice of SysV semaphores. Add some helpful comments. Improve the output of gen_export.pl by adding a header. TODO: who to credit for these? --- meson.build | 11 +++-------- src/Makefile.shlib | 2 +- src/backend/meson.build | 1 + src/backend/port/aix/mkldexport.sh | 17 ++++++++++++----- src/template/aix | 10 +++++----- src/tools/gen_export.pl | 6 +++++- 6 files changed, 27 insertions(+), 20 deletions(-) diff --git a/meson.build b/meson.build index 77a122b43c8..7e382aebab6 100644 --- a/meson.build +++ b/meson.build @@ -203,24 +203,19 @@ endif portname = host_system if host_system == 'aix' + sema_kind = 'unnamed_posix' library_path_var = 'LIBPATH' - export_file_format = 'aix' export_fmt = '-Wl,-bE:@0@' mod_link_args_fmt = ['-Wl,-bI:@0@'] mod_link_with_dir = 'libdir' mod_link_with_name = '@0@.imp' - # M:SRE sets a flag indicating that an object is a shared library. Seems to - # work in some circumstances without, but required in others. + # M:SRE sets a flag indicating that an object is a shared library. ldflags_sl += '-Wl,-bM:SRE' + # -brtllib indicates binaries should use runtime-loaded shared libraries. ldflags_be += '-Wl,-brtllib' - # Native memset() is faster, tested on: - # - AIX 5.1 and 5.2, XLC 6.0 (IBM's cc) - # - AIX 5.3 ML3, gcc 4.0.1 - memset_loop_limit = 0 - elif host_system == 'cygwin' sema_kind = 'unnamed_posix' cppflags += '-D_GNU_SOURCE' diff --git a/src/Makefile.shlib b/src/Makefile.shlib index 65870d629c2..cd1543550ca 100644 --- a/src/Makefile.shlib +++ b/src/Makefile.shlib @@ -268,7 +268,7 @@ $(stlib): $(OBJS) | $(SHLIB_PREREQS) touch $@ endif #haslibarule -# AIX wraps shared libraries inside a static library, can be used both +# AIX wraps shared libraries inside a static library, which can be used both # for static and shared linking ifeq ($(PORTNAME), aix) $(stlib): $(shlib) diff --git a/src/backend/meson.build b/src/backend/meson.build index ba273df24b5..130144a7d5b 100644 --- a/src/backend/meson.build +++ b/src/backend/meson.build @@ -104,6 +104,7 @@ elif host_system == 'aix' install_dir: dir_lib, build_by_default: false, ) + # -Wl,-bE:exportfile indicates these symbols are exported by postgres binary backend_link_args += '-Wl,-bE:@0@'.format(postgres_imp.full_path()) backend_link_depends += postgres_imp endif diff --git a/src/backend/port/aix/mkldexport.sh b/src/backend/port/aix/mkldexport.sh index adf3793e868..85631ce672a 100755 --- a/src/backend/port/aix/mkldexport.sh +++ b/src/backend/port/aix/mkldexport.sh @@ -13,14 +13,21 @@ # object file (if different from the current # working directory). # -# [This file comes from the Postgres 4.2 distribution. - ay 7/95] +# On AIX, executables do not automatically expose their symbols to shared +# modules. Extensions therefore cannot call functions in the main Postgres +# binary unless those symbols are explicitly exported. Unlike other platforms, +# AIX executables are not default symbol providers; each shared module must +# link against an export list that defines which symbols it can use. # -# Header: /usr/local/devel/postgres/src/tools/mkldexport/RCS/mkldexport.sh,v 1.2 1994/03/13 04:59:12 aoki Exp +# The mkldexport.sh script fixes AIX's symbol export issue by generating an +# explicit export list. It uses nm to gather all symbols from the Postgres +# object files, then writes them into the export file. When invoked with ".", +# it outputs #! ., which tells AIX the list applies to the main executable. +# This way, extension modules can link against that list and resolve their +# undefined symbols directly from the Postgres binary. # -# setting this to nm -B might be better -# ... due to changes in AIX 4.x ... -# ... let us search in different directories - Gerhard Reithofer +# Search for the nm command binary. if [ -x /usr/ucb/nm ] then NM=/usr/ucb/nm elif [ -x /usr/bin/nm ] diff --git a/src/template/aix b/src/template/aix index f39c680a314..c7c8706fea5 100644 --- a/src/template/aix +++ b/src/template/aix @@ -1,9 +1,9 @@ # src/template/aix +# Prefer unnamed POSIX semaphores if available, unless user overrides choice +if test x"$PREFERRED_SEMAPHORES" = x"" ; then + PREFERRED_SEMAPHORES=UNNAMED_POSIX +fi + # Extra CFLAGS for code that will go into a shared library CFLAGS_SL="" - -# Native memset() is faster, tested on: -# AIX 5.1 and 5.2, XLC 6.0 (IBM's cc) -# AIX 5.3 ML3, gcc 4.0.1 -MEMSET_LOOP_LIMIT=0 diff --git a/src/tools/gen_export.pl b/src/tools/gen_export.pl index 36f3b79bea7..c91fa42a675 100644 --- a/src/tools/gen_export.pl +++ b/src/tools/gen_export.pl @@ -31,7 +31,11 @@ open(my $output_handle, '>', $output) or die "$0: could not open output file '$output': $!\n"; -if ($format eq 'gnu') +if ($format eq 'aix') +{ + print $output_handle "#!\n"; +} +elsif ($format eq 'gnu') { print $output_handle "{ global: -- 2.43.7