Support passing arguments to g-ir-scanner through a file

--- gobject-introspection-1.60.1/Makefile.introspection.orig	2019-04-20 19:49:44.101084900 +0200
+++ gobject-introspection-1.60.1/Makefile.introspection	2019-04-20 19:49:56.487025600 +0200
@@ -132,6 +132,7 @@
 # needs to be added manually.
 $(1): $$($(_gir_name)_FILES)
 	@ $(MKDIR_P) $(dir $(1))
+	@ echo $$^ > $(1).files
 	$(_gir_silent_scanner_prefix) $(_gir_default_scanner_env) $(INTROSPECTION_SCANNER_ENV) $(INTROSPECTION_SCANNER) $(_gir_silent_scanner_opts) \
 	$(INTROSPECTION_SCANNER_ARGS) \
 	  --namespace=$(_gir_namespace) \
@@ -148,7 +149,7 @@
 	  $($(_gir_name)_CFLAGS) \
 	  --cflags-end \
 	  $($(_gir_name)_LDFLAGS) \
-	  $$^ \
+	  --argfile=$(1).files \
 	  --output $(1)
 endef
 
--- a/giscanner/scannermain.py	
+++ a/giscanner/scannermain.py	
@@ -470,8 +470,9 @@ def write_output(data, options):
 
 
 def scanner_main(args):
+    loaded_args = utils.maybe_load_args_from_file(args)
     parser = _get_option_parser()
-    (options, args) = parser.parse_args(args)
+    (options, args) = parser.parse_args(loaded_args)
 
     if options.passthrough_gir:
         passthrough_gir(options.passthrough_gir, sys.stdout)
--- gobject-introspection-1.58.1/giscanner/utils.py.orig	2018-11-05 19:58:03.000000000 +0100
+++ gobject-introspection-1.58.1/giscanner/utils.py	2018-11-18 12:24:53.599570100 +0100
@@ -29,6 +29,7 @@
 import platform
 import shutil
 import time
+import shlex
 import giscanner.pkgconfig
 
 
@@ -83,6 +84,59 @@
     return name
 
 
+def cygmsys_mangle(arg):
+    shell = which(os.environ.get('SHELL', 'sh.exe'))
+    p = subprocess.Popen([shell, '-c', 'cmd //C echo ' + arg], stdout=subprocess.PIPE)
+    result, _ = p.communicate()
+    return result.decode('utf-8').rstrip('\n').rstrip('\r') if p.returncode == 0 else None
+
+
+def load_args_from_file(filename):
+    with open(filename, 'rb') as source:
+        contents = source.read().decode('UTF-8')
+        result = shlex.split(contents)
+    if os.name == 'nt':
+        args = []
+        for arg in result:
+            mangled = cygmsys_mangle(arg)
+            if mangled is not None:
+                args.append(mangled)
+        result = args
+    return result
+
+
+def maybe_load_args_from_file(args):
+    if os.name != 'nt':
+        return args
+
+    processed_args = []
+    skip = False
+    is_input_file = False
+    argfilelen = len('--argfile=')
+    for argn, arg in enumerate(args):
+        if skip:
+            processed_args.append(arg)
+            continue
+        elif arg == '--':
+            skip = True
+            processed_args.append(arg)
+            continue
+
+        if is_input_file:
+            processed_args.extend(load_args_from_file(arg))
+            is_input_file = False
+            continue
+
+        if arg == '--argfile' and argn + 1 < len(args):
+            is_input_file = True
+            continue
+        elif arg.startswith('--argfile=') and len(arg) > argfilelen:
+            processed_args.extend(load_args_from_file(arg[argfilelen:]))
+            continue
+        processed_args.append(arg)
+    return processed_args
+
+
 _libtool_pat = re.compile("dlname='([A-z0-9\\.\\-\\+]+)'\n")