Re: Should we work around msvc failing to compile tab-complete.c? - Mailing list pgsql-hackers

Hi,

On 2024-07-09 17:44:27 -0400, Tom Lane wrote:
> Worst case: the reason no one uses readline under Windows is that it flat
> out doesn't work.

I've just tried it again, it works after splitting the else-if chain.



> One thing that struck me while looking at tab-complete.c just now is
> that there are aspects of the readline API that require strings to be
> malloc'd by the client (tab-complete.c) and later free'd within
> libreadline.  I wonder how that will play with Windows' weird rules
> about when one DLL's malloc pool will interoperate with another's
> (cf PQfreemem).

It seems to work fine as long as a debug-readline is paired with a debug-psql
or a release-readline is paired with a release-psql.


Intentionally cross-matching the two does indeed quickly crash, with stack
trace that looks like exactly the issue you describe.  This is a release
readline in a debug psql, but it shouldn't matter which way round.

Just doing "tab":

 # Child-SP          RetAddr               Call Site
00 00000017`db5ff430 00007ff9`1fa18182     ntdll!RtlReportCriticalFailure+0x56
01 00000017`db5ff520 00007ff9`1fa1846a     ntdll!RtlpHeapHandleError+0x12
02 00000017`db5ff550 00007ff9`1fa1e0f1     ntdll!RtlpHpHeapHandleError+0x7a
03 00000017`db5ff580 00007ff9`1f9b79d2     ntdll!RtlpLogHeapFailure+0x45
04 00000017`db5ff5b0 00007ff9`1f9347b1     ntdll!RtlpFreeHeapInternal+0x822c2
05 00000017`db5ff670 00007ff9`1d7df05b     ntdll!RtlFreeHeap+0x51
*** WARNING: Unable to verify checksum for
C:\dev\postgres-meson\build-ninja-2022\tmp_install\usr\local\pgsql\bin\readline.dll
06 00000017`db5ff6b0 00007ff8`f7ab637c     ucrtbase!_free_base+0x1b
07 (Inline Function) --------`--------     readline!_rl_free_match_list+0x19
[C:\dev\vcpkg\buildtrees\readline-win32\src\e6f798e014-dba5d3560f.clean\complete.c@ 1627]
 
08 00000017`db5ff6e0 00007ff8`f7ab12fc     readline!rl_complete_internal+0x4dc
[C:\dev\vcpkg\buildtrees\readline-win32\src\e6f798e014-dba5d3560f.clean\complete.c@ 1755]
 
09 00000017`db5ff750 00007ff8`f7ab1725     readline!_rl_dispatch_subseq+0x2dc
[C:\dev\vcpkg\buildtrees\readline-win32\src\e6f798e014-dba5d3560f.clean\readline.c@ 582]
 
0a (Inline Function) --------`--------     readline!_rl_dispatch+0x18
[C:\dev\vcpkg\buildtrees\readline-win32\src\e6f798e014-dba5d3560f.clean\readline.c@ 530]
 
0b 00000017`db5ff7a0 00007ff8`f7ab1625     readline!readline_internal_char+0xd5
[C:\dev\vcpkg\buildtrees\readline-win32\src\e6f798e014-dba5d3560f.clean\readline.c@ 449]
 
0c (Inline Function) --------`--------     readline!readline_internal_charloop+0x13
[C:\dev\vcpkg\buildtrees\readline-win32\src\e6f798e014-dba5d3560f.clean\readline.c@ 490]
 
0d (Inline Function) --------`--------     readline!readline_internal+0x18
[C:\dev\vcpkg\buildtrees\readline-win32\src\e6f798e014-dba5d3560f.clean\readline.c@ 504]
 
0e 00000017`db5ff7e0 00007ff7`6f1e9dba     readline!readline+0xb5
[C:\dev\vcpkg\buildtrees\readline-win32\src\e6f798e014-dba5d3560f.clean\readline.c@ 300]
 
0f 00000017`db5ff810 00007ff7`6f1eb211     psql!gets_interactive+0x3a [C:\dev\postgres-meson\src\bin\psql\input.c @
91]
10 00000017`db5ff850 00007ff7`6f1ee7ec     psql!MainLoop+0x3a1 [C:\dev\postgres-meson\src\bin\psql\mainloop.c @ 166]
11 00000017`db5ff980 00007ff7`6f287a99     psql!main+0xcfc [C:\dev\postgres-meson\src\bin\psql\startup.c @ 462]
12 00000017`db5ffaa0 00007ff7`6f2879e2     psql!invoke_main+0x39
[D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl@ 79]
 
13 00000017`db5ffaf0 00007ff7`6f28789e     psql!__scrt_common_main_seh+0x132
[D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl@ 288]
 
14 00000017`db5ffb60 00007ff7`6f287b0e     psql!__scrt_common_main+0xe
[D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl@ 331]
 
15 00000017`db5ffb90 00007ff9`1e9a7374     psql!mainCRTStartup+0xe
[D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_main.cpp@ 17]
 
16 00000017`db5ffbc0 00007ff9`1f95cc91     KERNEL32!BaseThreadInitThunk+0x14
17 00000017`db5ffbf0 00000000`00000000     ntdll!RtlUserThreadStart+0x21


executing a statement (crashes after execution):

 # Child-SP          RetAddr               Call Site
00 000000db`ae3ff898 00007ff9`1f9cd088     ntdll!RtlpBreakPointHeap+0x16
01 000000db`ae3ff8a0 00007ff9`1f96f6f5     ntdll!RtlpValidateHeapEntry+0x5d858
02 000000db`ae3ff8e0 00007ff9`1d2b6edb     ntdll!RtlValidateHeap+0x95
03 000000db`ae3ff930 00007ff8`ba38dc52     KERNELBASE!HeapValidate+0xb
04 000000db`ae3ff960 00007ff8`ba390a76     ucrtbased!_CrtIsValidHeapPointer+0x42
[minkernel\crts\ucrt\src\appcrt\heap\debug_heap.cpp@ 1407]
 
05 000000db`ae3ff9a0 00007ff8`ba38f565     ucrtbased!free_dbg_nolock+0x136
[minkernel\crts\ucrt\src\appcrt\heap\debug_heap.cpp@ 904]
 
06 000000db`ae3ffaa0 00007ff8`ba392118     ucrtbased!_free_dbg+0x55 [minkernel\crts\ucrt\src\appcrt\heap\debug_heap.cpp
@1030]
 
07 000000db`ae3ffae0 00007ff7`6f1ebd00     ucrtbased!free+0x28 [minkernel\crts\ucrt\src\appcrt\heap\free.cpp @ 39]
08 000000db`ae3ffb20 00007ff7`6f1ee7ec     psql!MainLoop+0xe90 [C:\dev\postgres-meson\src\bin\psql\mainloop.c @ 579]
09 000000db`ae3ffc50 00007ff7`6f287a99     psql!main+0xcfc [C:\dev\postgres-meson\src\bin\psql\startup.c @ 462]
0a 000000db`ae3ffd70 00007ff7`6f2879e2     psql!invoke_main+0x39
[D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl@ 79]
 
0b 000000db`ae3ffdc0 00007ff7`6f28789e     psql!__scrt_common_main_seh+0x132
[D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl@ 288]
 
0c 000000db`ae3ffe30 00007ff7`6f287b0e     psql!__scrt_common_main+0xe
[D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl@ 331]
 
0d 000000db`ae3ffe60 00007ff9`1e9a7374     psql!mainCRTStartup+0xe
[D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_main.cpp@ 17]
 
0e 000000db`ae3ffe90 00007ff9`1f95cc91     KERNEL32!BaseThreadInitThunk+0x14
0f 000000db`ae3ffec0 00000000`00000000     ntdll!RtlUserThreadStart+0x21

Note that the line numbers seem to commonly point to where the next frame
would return to (i.e. mainloop.c:579 is the call to free, but on return the if
(slashCmdStatus == PSQL_CMD_TERMINATE) would be reached, so that's displayed -
why I don't know).

Greetings,

Andres Freund