[m-rev.] for review: update to Boehm GC v8.2.4

[Julien Fischer]

On Tue, 11 Jul 2023, Peter Wang wrote:

> On Tue, 11 Jul 2023 12:16:56 +1000 Julien Fischer <jfischer at opturion.com> wrote:
>>
>>
>> On Tue, 11 Jul 2023, Julien Fischer wrote:
>>
>>> There is an issue with the 64-bit version of MSVC:
>>>
>>> ../scripts/ml --grade hlc.gc    --no-mercury-stdlib-dir
>>> --trace-init-file ../browser/mer_browser.init --trace-init-file
>>> ../mdbcomp/mer_mdbcomp.init --ssdb-init-file ../ssdb/mer_ssdb.init
>>> --    -Fechoose_grade.exe choose_grade_init.obj \
>>>        choose_grade.obj grade_lib.obj grade_lib.grade_setup.obj
>>> grade_lib.grade_solver.obj grade_lib.grade_spec.obj
>>> grade_lib.grade_state.obj grade_lib.grade_string.obj
>>> grade_lib.grade_structure.obj grade_lib.grade_vars.obj
>>> var_value_names.obj \
>>>        ../trace/libmer_trace.lib ../trace/libmer_eventspec.lib
>>> ../ssdb/libmer_ssdb.lib ../browser/libmer_browser.lib
>>> ../mdbcomp/libmer_mdbcomp.lib ../library/libmer_std.lib
>>> ../runtime/libmer_rt.lib ../boehm_gc/libgc.lib
>>> libgc.lib(misc.obj) : error LNK2019: unresolved external symbol
>>> __imp_MessageBoxA referenced in function GC_win32_MessageBoxA
>>
>> The following diff for boehm_gc/NT_MAKEFILE will resolve it.
>> (I don't now why message box in the fatal error handler is now the
>> default.)
>>
>
> Thanks. It looks like I made a mistake last year when preparing
> release-8_2-mercury-20221006-rc by losing the commit
> "Avoid linking with user32.dll on Windows." which does this:
>
> diff --git a/misc.c b/misc.c
> index 99747ecd..239fc433 100644
> --- a/misc.c
> +++ b/misc.c
> @@ -34,6 +34,8 @@
> # endif
> # define NOSERVICE
> # include <windows.h>
> +/* Mercury-specific: avoid linking with user32.dll */
> +#define DONT_USE_USER32_DLL
> #endif
>
> Should we:
> 1. define NO_MSGBOX_ON_ERROR, which prevents calling MessageBox
>    completely
> 2. define DONT_USE_USER32_DLL, which prevents statically linking to
>    user32.dll, but will try to look up MessageBox dynamically?

I suggest the latter (i.e. put it back the way it was).  The message
box is only used on a fatal error anyway.

Julien.