meson add mingw build support

meson.build

@@ -37,6 +37,10 @@ else
 endif
 
 cc = meson.get_compiler('c')
+if plat == 'win' and cc.get_id() != 'msvc' and get_option('win_force_msvc')
+    error('Tried to compile with a non-msvc compiler when msvc is forced')
+endif
+
 fs = import('fs')
 
 py = import('python').find_installation(pure: false)
@@ -55,7 +59,6 @@ pg_lib_dirs = []
 sdl_image_extra_links = []
 if (
     plat == 'win'
-    and cc.get_argument_syntax() == 'msvc'
     and host_machine.cpu_family().startswith('x86')
 )
     # yes, this is a bit ugly and hardcoded but it is what it is
@@ -105,12 +108,12 @@ if (
         'libpng',
         output: 'libpng16-16.lib',
         input: [libpng_def, sdl_image_lib_dir / 'libpng16-16.dll'],
-        command: [
+        command: cc.get_argument_syntax() == 'msvc' ? [
             'lib',
             '/def:' + libpng_def,
             '/machine:' + arch_suffix,
             '/out:@OUTPUT@',
-        ]
+        ] : ['dlltool', '-k', '--output-lib', '@OUTPUT@', '--def', libpng_def]
     )
 
     # SDL2_mixer
@@ -139,6 +142,19 @@ if (
     pg_lib_dirs += common_lib_dir
     dlls += [common_lib_dir / 'freetype.dll', common_lib_dir / 'portmidi.dll']
 
+    # clean unneeded file that causes build issues
+    unneeded_file = common_lib_dir / 'libportmidi.dll.a'
+    if fs.exists(unneeded_file)
+        run_command(
+            [
+                find_program('python3', 'python'),
+                '-c',
+                'import os; os.remove("@0@")'.format(unneeded_file),
+            ],
+            check: true,
+        )
+    endif
+
     # put dlls in root of install
     install_data(dlls, install_dir: pg_dir)
 else

meson_options.txt

@@ -29,3 +29,8 @@ option('stripped', type: 'boolean', value: 'false')
 # Controls whether to compile with -Werror (or its msvc equivalent). The default
 # behaviour is to not do this by default
 option('error_on_warns', type: 'boolean', value: 'false')
+
+# Controls whether to error on windows when a non msvc compiler is used. The
+# default behaviour is to not (and hence, the build can make use of something
+# like mingw). This option is ignored on other platforms.
+option('win_force_msvc', type: 'boolean', value: 'false')

pyproject.toml

@@ -56,4 +56,4 @@ build-backend = 'mesonpy'
 # setup = ["-Derror_on_warns=true"]
 
 [tool.cibuildwheel.config-settings]
-setup-args = "-Derror_on_warns=true"
+setup-args = ["-Derror_on_warns=true", "-Dwin_force_msvc=true"]