Re: pltcl crash on recent macOS

On Mon, Jun 13, 2022 at 6:53 PM Peter Eisentraut
<peter.eisentraut@enterprisedb.com> wrote:
>      frame #1: 0x00007ff803a28751 libsystem_c.dylib`hash_search + 215
>      frame #2: 0x0000000110357700
> pltcl.so`compile_pltcl_function(fn_oid=16418, tgreloid=0,

Hmm, I can’t reproduce that….  although that symbol is present in my
libSystem.B.dylib according to dlsym() and callable from a simple
program not linked to anything else, pltcl.so is apparently reaching
postgres’s hash_search for me, based on the fact that make -C
src/pl/tcl check succeeds and nm -m on pltcl.so shows it as "from
executable".  It would be interesting to see what nm -m shows for you.

Archeological note: That hash_search stuff, header <strhash.h>, seems
to have been copied from ancient FreeBSD before it was dropped
upstream for the crime of polluting the global symbol namespace with
junk[1].  It's been languishing in Apple's libc for at least 19
years[2], though, so I'm not sure why it's showing up suddenly as a
problem for you now.

> Note, I'm using the tcl-tk package from Homebrew.  The tcl installation
> provided by macOS itself no longer appears to work for linking against.

I’m using tcl 8.6.12 installed by MacPorts on macOS 12.4, though, hmm,
SDK 12.3.  I see the explicit -lc when building pltcl.so, and I see
that libSystem.B.dylib is explicitly mentioned here, whether or not I
have -lc:

% otool -L ./tmp_install/Users/tmunro/install/lib/postgresql/pltcl.so
./tmp_install/Users/tmunro/install/lib/postgresql/pltcl.so:
/opt/local/lib/libtcl8.6.dylib (compatibility version 8.6.0, current
version 8.6.12)
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current
version 1311.100.3)

Here’s the complete link line:

ccache cc -Wall -Wmissing-prototypes -Wpointer-arith
-Wdeclaration-after-statement -Werror=vla
-Werror=unguarded-availability-new -Wendif-labels
-Wmissing-format-attribute -Wcast-function-type -Wformat-security
-fno-strict-aliasing -fwrapv -Wno-unused-command-line-argument
-Wno-compound-token-split-by-macro -g -O0  -bundle -multiply_defined
suppress -o pltcl.so  pltcl.o -L../../../src/port
-L../../../src/common  -isysroot
/Library/Developer/CommandLineTools/SDKs/MacOSX12.3.sdk
-Wl,-dead_strip_dylibs   -L/opt/local/lib -ltcl8.6 -lz -lpthread
-framework CoreFoundation  -lc -bundle_loader
../../../src/backend/postgres

[1] https://github.com/freebsd/freebsd-src/commit/dc196afb2e58dd05cd66e2da44872bb3d619910f
[2] https://github.com/apple-open-source-mirror/Libc/blame/master/stdlib/FreeBSD/strhash.c