Merge branch 'win32' into 'main'

build-sys: drop -mms-bitfields GCC flag

See merge request GNOME/glib!3509

docs/win32-build.md

@@ -65,10 +65,10 @@ Building software that just *uses* GLib or GTK also require to have
 the right compiler set up the right way. If you intend to use MinGW-GCC,
 follow the relevant instructions below in that case, too.
 
-You should link to GLib using the `-mms-bitfields` GCC flag. This flag means
-that the struct layout rules are identical to those used by MSVC. This is
-essential if the same DLLs are to be usable both from gcc- and MSVC-compiled
-code.
+You should link to GLib using the `-mms-bitfields` GCC flag. It is the default
+since 2012 (GCC 4.7). This flag means that the struct layout rules are identical
+to those used by MSVC. This is essential if the same DLLs are to be usable both
+from gcc- and MSVC-compiled code.
 
 ## Cross-CRT issues
 

glib/meson.build

@@ -443,7 +443,7 @@ pkg.generate(libglib,
   libraries : [libintl_deps],
   libraries_private : [win32_ldflags],
   subdirs : ['glib-2.0'],
-  extra_cflags : ['-I${libdir}/glib-2.0/include'] + win32_cflags,
+  extra_cflags : ['-I${libdir}/glib-2.0/include'],
   variables : [
     'bindir=' + '${prefix}' / get_option('bindir'),
     'datadir=' + '${prefix}' / get_option('datadir'),

meson.build

@@ -50,7 +50,6 @@ if cc.get_id() == 'msvc'
   noseh_link_args = ['/SAFESEH:NO']
 else
   noseh_link_args = []
-  # -mms-bitfields vs -fnative-struct ?
 endif
 
 host_system = host_machine.system()
@@ -2346,15 +2345,8 @@ else
   export_dynamic_ldflags = ['-Wl,--export-dynamic']
 endif
 
-win32_cflags = []
 win32_ldflags = []
 if host_system == 'windows' and cc.get_id() != 'msvc' and cc.get_id() != 'clang-cl'
-  # Ensure MSVC-compatible struct packing convention is used when
-  # compiling for Win32 with gcc. It is used for the whole project and exposed
-  # in glib-2.0.pc.
-  win32_cflags = ['-mms-bitfields']
-  add_project_arguments(win32_cflags, language : 'c')
-
   # Win32 API libs, used only by libglib and exposed in glib-2.0.pc
   win32_ldflags = ['-lws2_32', '-lole32', '-lwinmm', '-lshlwapi', '-luuid']
 elif host_system == 'cygwin'