Merge pull request matplotlib#23060 from greglucas/macosx-ARC

MNT: Change objective C code to Automatic Reference Counting (ARC)

Author: greglucas

setupext.py

@@ -762,7 +762,7 @@ def get_extensions(self):
             'matplotlib.backends._macosx', [
                 'src/_macosx.m'
             ])
-        ext.extra_compile_args.extend(['-Werror'])
+        ext.extra_compile_args.extend(['-Werror', '-fobjc-arc'])
         ext.extra_link_args.extend(['-framework', 'Cocoa'])
         if platform.python_implementation().lower() == 'pypy':
             ext.extra_compile_args.append('-DPYPY=1')

src/_macosx.m

@@ -1,3 +1,7 @@
+#if  ! __has_feature(objc_arc)
+#error This file must be compiled with ARC. Use -fobjc-arc flag (or convert project to ARC).
+#endif
+
 #define PY_SSIZE_T_CLEAN
 #include <Cocoa/Cocoa.h>
 #include <ApplicationServices/ApplicationServices.h>
@@ -333,15 +337,14 @@ static CGFloat _get_device_scale(CGContextRef cr)
 FigureCanvas_dealloc(FigureCanvas* self)
 {
     [self->view setCanvas: NULL];
-    [self->view release];
     Py_TYPE(self)->tp_free((PyObject*)self);
 }
 
 static PyObject*
 FigureCanvas_repr(FigureCanvas* self)
 {
     return PyUnicode_FromFormat("FigureCanvas object %p wrapping NSView %p",
-                               (void*)self, (void*)(self->view));
+                               (void*)self, (__bridge void*)(self->view));
 }
 
 static PyObject*
@@ -545,7 +548,6 @@ static CGFloat _get_device_scale(CGContextRef cr)
     if (!window) { return NULL; }
     FigureManager *self = (FigureManager*)type->tp_alloc(type, 0);
     if (!self) {
-        [window release];
         return NULL;
     }
     self->window = window;
@@ -598,7 +600,7 @@ static CGFloat _get_device_scale(CGContextRef cr)
 FigureManager_repr(FigureManager* self)
 {
     return PyUnicode_FromFormat("FigureManager object %p wrapping NSWindow %p",
-                               (void*) self, (void*)(self->window));
+                               (void*) self, (__bridge void*)(self->window));
 }
 
 static void
@@ -648,7 +650,7 @@ static CGFloat _get_device_scale(CGContextRef cr)
             PyErr_SetString(PyExc_RuntimeError, "Could not convert to NSString*");
             return NULL;
         }
-        NSImage* image = [[[NSImage alloc] initByReferencingFile: ns_icon_path] autorelease];
+        NSImage* image = [[NSImage alloc] initByReferencingFile: ns_icon_path];
         if (!image) {
             PyErr_SetString(PyExc_RuntimeError, "Could not create NSImage*");
             return NULL;
@@ -677,9 +679,9 @@ static CGFloat _get_device_scale(CGContextRef cr)
     if (!PyArg_ParseTuple(args, "s", &title)) {
         return NULL;
     }
-    NSString* ns_title = [[[NSString alloc]
-                           initWithCString: title
-                           encoding: NSUTF8StringEncoding] autorelease];
+    NSString* ns_title = [[NSString alloc]
+                          initWithCString: title
+                          encoding: NSUTF8StringEncoding];
     [self->window setTitle: ns_title];
     Py_RETURN_NONE;
 }
@@ -766,7 +768,7 @@ @interface NavigationToolbar2Handler : NSObject
     NSButton* zoombutton;
 }
 - (NavigationToolbar2Handler*)initWithToolbar:(PyObject*)toolbar;
-- (void)installCallbacks:(SEL[7])actions forButtons:(NSButton*[7])buttons;
+- (void)installCallbacks:(SEL[7])actions forButtons:(NSButton*__strong [7])buttons;
 - (void)home:(id)sender;
 - (void)back:(id)sender;
 - (void)forward:(id)sender;
@@ -787,12 +789,12 @@ - (void)save_figure:(id)sender;
 @implementation NavigationToolbar2Handler
 - (NavigationToolbar2Handler*)initWithToolbar:(PyObject*)theToolbar
 {
-    [self init];
+    self = [self init];
     toolbar = theToolbar;
     return self;
 }
 
-- (void)installCallbacks:(SEL[7])actions forButtons:(NSButton*[7])buttons
+- (void)installCallbacks:(SEL[7])actions forButtons:(NSButton*__strong [7])buttons
 {
     int i;
     for (i = 0; i < 7; i++) {
@@ -833,7 +835,6 @@ -(void)save_figure:(id)sender { gil_call_method(toolbar, "save_figure"); }
     if (!handler) { return NULL; }
     NavigationToolbar2 *self = (NavigationToolbar2*)type->tp_alloc(type, 0);
     if (!self) {
-        [handler release];
         return NULL;
     }
     self->handler = handler;
@@ -925,8 +926,6 @@ -(void)save_figure:(id)sender { gil_call_method(toolbar, "save_figure"); }
         [buttons[i] setImagePosition: NSImageOnly];
         [buttons[i] setToolTip: tooltip];
         [[window contentView] addSubview: buttons[i]];
-        [buttons[i] release];
-        [image release];
         rect.origin.x += rect.size.width + gap;
     }
 
@@ -939,7 +938,7 @@ -(void)save_figure:(id)sender { gil_call_method(toolbar, "save_figure"); }
     // Make it a zero-width box if we don't have enough room
     rect.size.width = fmax(bounds.size.width - rect.origin.x, 0);
     rect.origin.x = bounds.size.width - rect.size.width;
-    NSTextView* messagebox = [[[NSTextView alloc] initWithFrame: rect] autorelease];
+    NSTextView* messagebox = [[NSTextView alloc] initWithFrame: rect];
     messagebox.textContainer.maximumNumberOfLines = 2;
     messagebox.textContainer.lineBreakMode = NSLineBreakByTruncatingTail;
     messagebox.alignment = NSTextAlignmentRight;
@@ -949,7 +948,6 @@ -(void)save_figure:(id)sender { gil_call_method(toolbar, "save_figure"); }
     /* if selectable, the messagebox can become first responder,
      * which is not supposed to happen */
     [[window contentView] addSubview: messagebox];
-    [messagebox release];
     [[window contentView] display];
 
     self->messagebox = messagebox;
@@ -959,7 +957,6 @@ -(void)save_figure:(id)sender { gil_call_method(toolbar, "save_figure"); }
 static void
 NavigationToolbar2_dealloc(NavigationToolbar2 *self)
 {
-    [self->handler release];
     Py_TYPE(self)->tp_free((PyObject*)self);
 }
 
@@ -1060,36 +1057,6 @@ + (WindowServerConnectionManager *)sharedManager
     return sharedWindowServerConnectionManager;
 }
 
-+ (id)allocWithZone:(NSZone *)zone
-{
-    return [[self sharedManager] retain];
-}
-
-+ (id)copyWithZone:(NSZone *)zone
-{
-    return self;
-}
-
-+ (id)retain
-{
-    return self;
-}
-
-- (NSUInteger)retainCount
-{
-    return NSUIntegerMax;  //denotes an object that cannot be released
-}
-
-- (oneway void)release
-{
-    // Don't release a singleton object
-}
-
-- (id)autorelease
-{
-    return self;
-}
-
 - (void)launch:(NSNotification*)notification
 {
     CFRunLoopRef runloop;
@@ -1167,7 +1134,6 @@ - (void)dealloc
      * content view of this window was increased during the call to addSubview,
      * and is decreased during the call to [super dealloc].
      */
-    [super dealloc];
 }
 @end
 
@@ -1189,7 +1155,6 @@ - (void)dealloc
 {
     FigureCanvas* fc = (FigureCanvas*)canvas;
     if (fc) { fc->view = NULL; }
-    [super dealloc];
 }
 
 - (void)setCanvas: (PyObject*)newCanvas