Mono/C#: Fix MinGW build not supporting `.lib` libraries

MinGW should support both its own format `.a` and MSVC's format `.lib`,
but Mono's module was only using the former. With this change it's now
possible to build with MinGW and link the official Mono for Windows
which is built with MSVC.

modules/mono/build_scripts/mono_configure.py

@@ -25,12 +25,26 @@ def get_android_out_dir(env):
     )
 
 
-def find_file_in_dir(directory, files, prefix="", extension=""):
-    if not extension.startswith("."):
-        extension = "." + extension
-    for curfile in files:
-        if os.path.isfile(os.path.join(directory, prefix + curfile + extension)):
-            return curfile
+def find_name_in_dir_files(directory, names, prefixes=[""], extensions=[""]):
+    for extension in extensions:
+        if extension and not extension.startswith("."):
+            extension = "." + extension
+        for prefix in prefixes:
+            for curname in names:
+                if os.path.isfile(os.path.join(directory, prefix + curname + extension)):
+                    return curname
+    return ""
+
+
+def find_file_in_dir(directory, names, prefixes=[""], extensions=[""]):
+    for extension in extensions:
+        if extension and not extension.startswith("."):
+            extension = "." + extension
+        for prefix in prefixes:
+            for curname in names:
+                filename = prefix + curname + extension
+                if os.path.isfile(os.path.join(directory, filename)):
+                    return filename
     return ""
 
 
@@ -126,7 +140,11 @@ def configure(env, env_mono):
         env.Append(LIBPATH=mono_lib_path)
         env_mono.Prepend(CPPPATH=os.path.join(mono_root, "include", "mono-2.0"))
 
-        lib_suffix = Environment()["LIBSUFFIX"]
+        lib_suffixes = [".lib"]
+
+        if not env.msvc:
+            # MingW supports both '.a' and '.lib'
+            lib_suffixes.insert(0, ".a")
 
         if mono_static:
             if env.msvc:
@@ -134,40 +152,45 @@ def configure(env, env_mono):
             else:
                 mono_static_lib_name = "libmonosgen-2.0"
 
-            if not os.path.isfile(os.path.join(mono_lib_path, mono_static_lib_name + lib_suffix)):
+            mono_static_lib_file = find_file_in_dir(mono_lib_path, [mono_static_lib_name], extensions=lib_suffixes)
+
+            if not mono_static_lib_file:
                 raise RuntimeError("Could not find static mono library in: " + mono_lib_path)
 
             if env.msvc:
-                env.Append(LINKFLAGS=mono_static_lib_name + lib_suffix)
+                env.Append(LINKFLAGS=mono_static_lib_file)
 
-                env.Append(LINKFLAGS="Mincore" + lib_suffix)
-                env.Append(LINKFLAGS="msvcrt" + lib_suffix)
-                env.Append(LINKFLAGS="LIBCMT" + lib_suffix)
-                env.Append(LINKFLAGS="Psapi" + lib_suffix)
+                env.Append(LINKFLAGS="Mincore.lib")
+                env.Append(LINKFLAGS="msvcrt.lib")
+                env.Append(LINKFLAGS="LIBCMT.lib")
+                env.Append(LINKFLAGS="Psapi.lib")
             else:
-                env.Append(LINKFLAGS=os.path.join(mono_lib_path, mono_static_lib_name + lib_suffix))
+                mono_static_lib_file_path = os.path.join(mono_lib_path, mono_static_lib_file)
+                env.Append(LINKFLAGS=["-Wl,-whole-archive", mono_static_lib_file_path, "-Wl,-no-whole-archive"])
 
                 env.Append(LIBS=["psapi"])
                 env.Append(LIBS=["version"])
         else:
-            mono_lib_name = find_file_in_dir(mono_lib_path, mono_lib_names, extension=lib_suffix)
+            mono_lib_name = find_name_in_dir_files(
+                mono_lib_path, mono_lib_names, prefixes=["", "lib"], extensions=lib_suffixes
+            )
 
             if not mono_lib_name:
                 raise RuntimeError("Could not find mono library in: " + mono_lib_path)
 
             if env.msvc:
-                env.Append(LINKFLAGS=mono_lib_name + lib_suffix)
+                env.Append(LINKFLAGS=mono_lib_name + ".lib")
             else:
                 env.Append(LIBS=[mono_lib_name])
 
             mono_bin_path = os.path.join(mono_root, "bin")
 
-            mono_dll_name = find_file_in_dir(mono_bin_path, mono_lib_names, extension=".dll")
+            mono_dll_file = find_file_in_dir(mono_bin_path, mono_lib_names, prefixes=["", "lib"], extensions=[".dll"])
 
-            if not mono_dll_name:
+            if not mono_dll_file:
                 raise RuntimeError("Could not find mono shared library in: " + mono_bin_path)
 
-            copy_file(mono_bin_path, "#bin", mono_dll_name + ".dll")
+            copy_file(mono_bin_path, "#bin", mono_dll_file)
     else:
         is_apple = env["platform"] in ["osx", "iphone"]
 
@@ -175,7 +198,7 @@ def configure(env, env_mono):
 
         mono_root = mono_prefix
         mono_lib_path = ""
-        mono_so_name = ""
+        mono_so_file = ""
 
         if not mono_root and (is_android or is_javascript):
             raise RuntimeError(
@@ -208,7 +231,7 @@ def configure(env, env_mono):
             env.Append(LIBPATH=[mono_lib_path])
             env_mono.Prepend(CPPPATH=os.path.join(mono_root, "include", "mono-2.0"))
 
-            mono_lib = find_file_in_dir(mono_lib_path, mono_lib_names, prefix="lib", extension=".a")
+            mono_lib = find_name_in_dir_files(mono_lib_path, mono_lib_names, prefixes=["lib"], extensions=[".a"])
 
             if not mono_lib:
                 raise RuntimeError("Could not find mono library in: " + mono_lib_path)
@@ -268,12 +291,12 @@ def configure(env, env_mono):
                 env.Append(LIBS=["m", "rt", "dl", "pthread"])
 
             if not mono_static:
-                mono_so_name = find_file_in_dir(mono_lib_path, mono_lib_names, prefix="lib", extension=sharedlib_ext)
+                mono_so_file = find_file_in_dir(
+                    mono_lib_path, mono_lib_names, prefixes=["lib"], extensions=[sharedlib_ext]
+                )
 
-                if not mono_so_name:
+                if not mono_so_file:
                     raise RuntimeError("Could not find mono shared library in: " + mono_lib_path)
-
-                copy_file(mono_lib_path, "#bin", "lib" + mono_so_name + sharedlib_ext)
         else:
             assert not mono_static
 
@@ -288,18 +311,18 @@ def configure(env, env_mono):
             tmpenv.ParseConfig("pkg-config monosgen-2 --libs-only-L")
 
             for hint_dir in tmpenv["LIBPATH"]:
-                name_found = find_file_in_dir(hint_dir, mono_lib_names, prefix="lib", extension=sharedlib_ext)
-                if name_found:
+                file_found = find_file_in_dir(hint_dir, mono_lib_names, prefixes=["lib"], extensions=[sharedlib_ext])
+                if file_found:
                     mono_lib_path = hint_dir
-                    mono_so_name = name_found
+                    mono_so_file = file_found
                     break
 
-            if not mono_so_name:
+            if not mono_so_file:
                 raise RuntimeError("Could not find mono shared library in: " + str(tmpenv["LIBPATH"]))
 
         if not mono_static:
             libs_output_dir = get_android_out_dir(env) if is_android else "#bin"
-            copy_file(mono_lib_path, libs_output_dir, "lib" + mono_so_name + sharedlib_ext)
+            copy_file(mono_lib_path, libs_output_dir, mono_so_file)
 
     if not tools_enabled:
         if is_desktop(env["platform"]):
@@ -454,11 +477,11 @@ def copy_mono_shared_libs(env, mono_root, target_mono_root_dir):
         if not os.path.isdir(target_mono_bin_dir):
             os.makedirs(target_mono_bin_dir)
 
-        mono_posix_helper_name = find_file_in_dir(
-            src_mono_bin_dir, ["MonoPosixHelper", "libMonoPosixHelper"], extension=".dll"
+        mono_posix_helper_file = find_file_in_dir(
+            src_mono_bin_dir, ["MonoPosixHelper"], prefixes=["", "lib"], extensions=[".dll"]
         )
         copy(
-            os.path.join(src_mono_bin_dir, mono_posix_helper_name + ".dll"),
+            os.path.join(src_mono_bin_dir, mono_posix_helper_file),
             os.path.join(target_mono_bin_dir, "MonoPosixHelper.dll"),
         )
 
@@ -504,7 +527,7 @@ def pkgconfig_try_find_mono_root(mono_lib_names, sharedlib_ext):
     tmpenv.AppendENVPath("PKG_CONFIG_PATH", os.getenv("PKG_CONFIG_PATH"))
     tmpenv.ParseConfig("pkg-config monosgen-2 --libs-only-L")
     for hint_dir in tmpenv["LIBPATH"]:
-        name_found = find_file_in_dir(hint_dir, mono_lib_names, prefix="lib", extension=sharedlib_ext)
+        name_found = find_name_in_dir_files(hint_dir, mono_lib_names, prefixes=["lib"], extensions=[sharedlib_ext])
         if name_found and os.path.isdir(os.path.join(hint_dir, "..", "include", "mono-2.0")):
             return os.path.join(hint_dir, "..")
     return ""