fix: remove abusive uses of catch unreachable

zenith391 · zenith391 · commit 40ea537dac61 · 2025-07-25T12:18:34.000Z
closes #106
diff --git a/build_capy.zig b/build_capy.zig
@@ -48,7 +48,7 @@ const WebServerStep = struct {
     options: CapyRunOptions,
 
     pub fn create(owner: *std.Build, exe: *std.Build.Step.Compile, options: CapyRunOptions) *WebServerStep {
-        const self = owner.allocator.create(WebServerStep) catch unreachable;
+        const self = owner.allocator.create(WebServerStep) catch @panic("OOM");
         self.* = .{
             .step = std.Build.Step.init(.{
                 .id = .custom,
diff --git a/examples/calculator.zig b/examples/calculator.zig
@@ -31,7 +31,7 @@ pub fn erase(_: *anyopaque) !void {
 }
 
 fn findOperator(computation: []const u8, pos: usize) ?usize {
-    return std.mem.indexOfScalarPos(u8, computation, pos, '+') orelse std.mem.indexOfScalarPos(u8, computation, pos, '-') orelse std.mem.indexOfScalarPos(u8, computation, pos, '*') orelse std.mem.indexOfScalarPos(u8, computation, pos, '/');
+    return std.mem.indexOfAnyPos(u8, computation, pos, "+-*/");
 }
 
 // TODO: switch back to *capy.button_Impl when ziglang/zig#12325 is fixed
diff --git a/src/backends/gtk/Label.zig b/src/backends/gtk/Label.zig
@@ -37,10 +37,10 @@ fn setText_uiThread(userdata: ?*anyopaque) callconv(.C) c_int {
 }
 
 pub fn setText(self: *Label, text: []const u8) void {
-    self.nullTerminated = lib.internal.allocator.dupeZ(u8, text) catch unreachable;
+    self.nullTerminated = lib.internal.allocator.dupeZ(u8, text) catch @panic("OOM");
 
     // It must be run in UI thread otherwise set_text might crash randomly
-    const runOpts = lib.internal.allocator.create(RunOpts) catch unreachable;
+    const runOpts = lib.internal.allocator.create(RunOpts) catch @panic("OOM");
     runOpts.* = .{
         .label = @as(*c.GtkLabel, @ptrCast(self.peer)),
         .text = self.nullTerminated.?,
diff --git a/src/backends/gtk/common.zig b/src/backends/gtk/common.zig
@@ -90,7 +90,7 @@ pub fn Events(comptime T: type) type {
             if (finalKeyval >= 32768) return 0;
             const codepoint = c.gdk_keyval_to_unicode(finalKeyval);
             var buf: [4]u8 = undefined;
-            const str_length = std.unicode.utf8Encode(@intCast(codepoint), &buf) catch unreachable;
+            const str_length = std.unicode.utf8Encode(@intCast(codepoint), &buf) catch unreachable; // unreachable because 'buf' is big enough
             const str = buf[0..str_length];
 
             if (str.len != 0) {
diff --git a/src/backends/wasm/Button.zig b/src/backends/wasm/Button.zig
@@ -34,7 +34,7 @@ pub fn getLabel(self: *const Button) [:0]const u8 {
         return text;
     } else {
         const len = js.getTextLen(self.peer.element);
-        const text = lib.lasting_allocator.allocSentinel(u8, len, 0) catch unreachable;
+        const text = lib.lasting_allocator.allocSentinel(u8, len, 0) catch @panic("OOM");
         js.getText(self.peer.element, text.ptr);
         self.temp_label = text;
 
diff --git a/src/backends/wasm/Container.zig b/src/backends/wasm/Container.zig
@@ -23,7 +23,7 @@ pub fn create() !Container {
 
 pub fn add(self: *Container, peer: *GuiWidget) void {
     js.appendElement(self.peer.element, peer.element);
-    self.peer.children.append(peer) catch unreachable;
+    self.peer.children.append(peer) catch @panic("OOM");
 }
 
 pub fn remove(self: *const Container, peer: *GuiWidget) void {
diff --git a/src/backends/wasm/Label.zig b/src/backends/wasm/Label.zig
@@ -35,7 +35,7 @@ pub fn setFont(self: *Label, font: lib.Font) void {
         js.setStyle(
             self.peer.element,
             "fontSize",
-            std.fmt.bufPrint(&buf, "{d}pt", .{size}) catch unreachable,
+            std.fmt.bufPrint(&buf, "{d}pt", .{size}) catch @panic("OOM"),
         );
     } else {
         js.removeAttribute(self.peer.element, "fontSize");
@@ -55,7 +55,7 @@ pub fn getText(self: *Label) []const u8 {
         return text;
     } else {
         const len = js.getTextLen(self.peer.element);
-        const text = lib.lasting_allocator.allocSentinel(u8, len, 0) catch unreachable;
+        const text = lib.lasting_allocator.allocSentinel(u8, len, 0) catch @panic("OOM");
         js.getText(self.peer.element, text.ptr);
         self.temp_text = text;
 
diff --git a/src/backends/wasm/TextField.zig b/src/backends/wasm/TextField.zig
@@ -7,6 +7,7 @@ const Events = common.Events;
 const TextField = @This();
 
 peer: *GuiWidget,
+text: ?[:0]const u8 = null,
 
 pub usingnamespace Events(TextField);
 
@@ -24,11 +25,14 @@ pub fn setText(self: *TextField, text: []const u8) void {
 }
 
 pub fn getText(self: *TextField) [:0]const u8 {
+    if (self.text) |previous_text| {
+        lib.allocator.free(previous_text);
+    }
+
     const len = js.getTextLen(self.peer.element);
-    // TODO: fix the obvious memory leak
-    const text = lib.lasting_allocator.allocSentinel(u8, len, 0) catch unreachable;
+    const text = lib.lasting_allocator.allocSentinel(u8, len, 0) catch @panic("OOM");
     js.getText(self.peer.element, text.ptr);
-
+    self.text = text;
     return text;
 }
 
diff --git a/src/backends/win32/Monitor.zig b/src/backends/win32/Monitor.zig
@@ -35,8 +35,8 @@ pub fn getList() []Monitor {
             while (win32.EnumDisplayDevicesW(null, i, &display_device, 0) != 0) : (i += 1) {
                 if (display_device.StateFlags & win32.DISPLAY_DEVICE_ATTACHED_TO_DESKTOP != 0) {
                     const device_name: [:0]const u16 = std.mem.span(@as([*:0]u16, @ptrCast(&display_device.DeviceName)));
-                    const cloned_device_name = allocator.dupeZ(u16, device_name) catch unreachable;
-                    adapters.append(cloned_device_name) catch unreachable;
+                    const cloned_device_name = allocator.dupeZ(u16, device_name) catch @panic("OOM");
+                    adapters.append(cloned_device_name) catch @panic("OOM");
                 }
             }
         }
@@ -62,23 +62,23 @@ pub fn getList() []Monitor {
                 var i: u32 = 0;
                 while (win32.EnumDisplayDevicesW(adapter, i, &display_device, 0) != 0) : (i += 1) {
                     const device_name: [:0]const u16 = std.mem.span(@as([*:0]u16, @ptrCast(&display_device.DeviceName)));
-                    const cloned_device_name = allocator.dupeZ(u16, device_name) catch unreachable;
+                    const cloned_device_name = allocator.dupeZ(u16, device_name) catch @panic("OOM");
                     const device_string: [:0]const u16 = std.mem.span(@as([*:0]u16, @ptrCast(&display_device.DeviceString)));
-                    const cloned_device_string = std.unicode.utf16LeToUtf8Alloc(allocator, device_string) catch unreachable;
-                    monitor_names.append(.{ .adapter = adapter, .monitor_name = cloned_device_name, .monitor_friendly_name = cloned_device_string }) catch unreachable;
+                    const cloned_device_string = std.unicode.utf16LeToUtf8Alloc(allocator, device_string) catch @panic("OOM");
+                    monitor_names.append(.{ .adapter = adapter, .monitor_name = cloned_device_name, .monitor_friendly_name = cloned_device_string }) catch @panic("OOM");
                 }
             }
         }
 
         for (monitor_names.items) |name| {
             monitors.append(Monitor{
-                .adapter_win32_name = allocator.dupeZ(u16, name.adapter) catch unreachable,
-                .win32_name = allocator.dupeZ(u16, name.monitor_name) catch unreachable,
-                .device_name = allocator.dupe(u8, name.monitor_friendly_name) catch unreachable,
-            }) catch unreachable;
+                .adapter_win32_name = allocator.dupeZ(u16, name.adapter) catch @panic("OOM"),
+                .win32_name = allocator.dupeZ(u16, name.monitor_name) catch @panic("OOM"),
+                .device_name = allocator.dupe(u8, name.monitor_friendly_name) catch @panic("OOM"),
+            }) catch @panic("OOM");
         }
 
-        monitor_list = monitors.toOwnedSlice() catch unreachable;
+        monitor_list = monitors.toOwnedSlice() catch @panic("OOM");
         return monitor_list.?;
     }
 }
diff --git a/src/backends/win32/backend.zig b/src/backends/win32/backend.zig
@@ -999,7 +999,7 @@ pub const TextField = struct {
 
     pub fn getText(self: *TextField) [:0]const u8 {
         const len = win32.GetWindowTextLengthW(self.peer);
-        var buf = lib.internal.allocator.allocSentinel(u16, @as(usize, @intCast(len)), 0) catch unreachable; // TODO return error
+        var buf = lib.internal.allocator.allocSentinel(u16, @as(usize, @intCast(len)), 0) catch @panic("OOM");
         defer lib.internal.allocator.free(buf);
         const realLen = @as(usize, @intCast(win32.GetWindowTextW(self.peer, buf.ptr, len + 1)));
         const utf16Slice = buf[0..realLen];
@@ -1060,11 +1060,11 @@ pub const TextArea = struct {
     pub fn getText(self: *TextArea) [:0]const u8 {
         const allocator = self.arena.allocator();
         const len = win32.GetWindowTextLengthW(self.peer);
-        var buf = allocator.allocSentinel(u16, @as(usize, @intCast(len)), 0) catch unreachable; // TODO return error
+        var buf = allocator.allocSentinel(u16, @as(usize, @intCast(len)), 0) catch @panic("OOM");
         defer allocator.free(buf);
         const realLen = @as(usize, @intCast(win32.GetWindowTextW(self.peer, buf.ptr, len + 1)));
         const utf16Slice = buf[0..realLen];
-        const text = std.unicode.utf16LeToUtf8AllocZ(allocator, utf16Slice) catch unreachable; // TODO return error
+        const text = std.unicode.utf16LeToUtf8AllocZ(allocator, utf16Slice) catch @panic("OOM");
         return text;
     }
 
@@ -1122,11 +1122,11 @@ pub const Button = struct {
     pub fn getLabel(self: *Button) [:0]const u8 {
         const allocator = self.arena.allocator();
         const len = win32.GetWindowTextLengthW(self.peer);
-        var buf = allocator.allocSentinel(u16, @as(usize, @intCast(len)), 0) catch unreachable; // TODO return error
+        var buf = allocator.allocSentinel(u16, @as(usize, @intCast(len)), 0) catch @panic("OOM");
         defer allocator.free(buf);
         const realLen = @as(usize, @intCast(win32.GetWindowTextW(self.peer, buf.ptr, len + 1)));
         const utf16Slice = buf[0..realLen];
-        const text = std.unicode.utf16leToUtf8AllocZ(allocator, utf16Slice) catch unreachable; // TODO return error
+        const text = std.unicode.utf16leToUtf8AllocZ(allocator, utf16Slice) catch @panic("OOM");
         return text;
     }
 
@@ -1415,7 +1415,7 @@ pub const TabContainer = struct {
     pub fn insert(self: *TabContainer, position: usize, peer: PeerType) usize {
         const item = win32Backend.TCITEMA{ .mask = 0 };
         const newIndex = win32Backend.TabCtrl_InsertItemW(self.tabControl, @as(c_int, @intCast(position)), &item);
-        self.peerList.append(peer) catch unreachable;
+        self.peerList.append(peer) catch @panic("OOM");
 
         if (self.shownPeer == null) {
             _ = win32.SetParent(peer, self.peer);
diff --git a/src/capy.zig b/src/capy.zig
@@ -112,13 +112,13 @@ pub fn init() !void {
 
     Monitors.init();
 
-    var timerListener = eventStep.listen(.{ .callback = @import("timer.zig").handleTimersTick }) catch unreachable;
+    var timerListener = eventStep.listen(.{ .callback = @import("timer.zig").handleTimersTick }) catch @panic("OOM");
     // The listener is enabled only if there is at least 1 timer is running
     timerListener.enabled.dependOn(.{&@import("timer.zig").runningTimers.length}, &struct {
         fn a(num: usize) bool {
             return num >= 1;
         }
-    }.a) catch unreachable;
+    }.a) catch @panic("OOM");
     isCapyInitialized = true;
 }
 
diff --git a/src/components/Menu.zig b/src/components/Menu.zig
@@ -27,10 +27,10 @@ pub fn menuItem(config: Config) MenuItem {
 
 /// 'items' is a tuple
 pub fn menu(config: Config, items: anytype) MenuItem {
-    return MenuItem{ .config = config, .items = internal.allocator.dupe(MenuItem, &items) catch unreachable };
+    return MenuItem{ .config = config, .items = internal.allocator.dupe(MenuItem, &items) catch @panic("OOM ") };
 }
 
 /// 'menus' is a tuple
 pub fn menuBar(menus: anytype) MenuBar {
-    return MenuBar{ .menus = internal.allocator.dupe(MenuItem, &menus) catch unreachable };
+    return MenuBar{ .menus = internal.allocator.dupe(MenuItem, &menus) catch @panic("OOM") };
 }
diff --git a/src/containers.zig b/src/containers.zig
@@ -305,7 +305,6 @@ pub fn GridLayout(peer: Callbacks, widgets: []*Widget) void {
         height: f32,
     };
 
-    // TODO: use explicit bounded arrays so as to avoid out-of-memory
     const MAX_COLUMNS = 10_000;
     const MAX_ROWS = 10_000;
 
diff --git a/src/data.zig b/src/data.zig
diff --git a/src/timer.zig b/src/timer.zig
diff --git a/src/window.zig b/src/window.zig

Original file line number	Diff line number	Diff line change
`@@ -31,7 +31,7 @@ pub fn erase(_: *anyopaque) !void {`
`31`	`31`	`}`
`32`	`32`
`33`	`33`	`fn findOperator(computation: []const u8, pos: usize) ?usize {`
`34`		`- return std.mem.indexOfScalarPos(u8, computation, pos, '+') orelse std.mem.indexOfScalarPos(u8, computation, pos, '-') orelse std.mem.indexOfScalarPos(u8, computation, pos, '*') orelse std.mem.indexOfScalarPos(u8, computation, pos, '/');`
	`34`	`+ return std.mem.indexOfAnyPos(u8, computation, pos, "+-*/");`
`35`	`35`	`}`
`36`	`36`
`37`	`37`	`// TODO: switch back to *capy.button_Impl when ziglang/zig#12325 is fixed`
Original file line number	Diff line number	Diff line change
`@@ -23,7 +23,7 @@ pub fn create() !Container {`
`23`	`23`
`24`	`24`	`pub fn add(self: Container, peer: GuiWidget) void {`
`25`	`25`	`js.appendElement(self.peer.element, peer.element);`
`26`		`- self.peer.children.append(peer) catch unreachable;`
	`26`	`+ self.peer.children.append(peer) catch @panic("OOM");`
`27`	`27`	`}`
`28`	`28`
`29`	`29`	`pub fn remove(self: const Container, peer: GuiWidget) void {`
Original file line number	Diff line number	Diff line change
`@@ -35,8 +35,8 @@ pub fn getList() []Monitor {`
`35`	`35`	`while (win32.EnumDisplayDevicesW(null, i, &display_device, 0) != 0) : (i += 1) {`
`36`	`36`	`if (display_device.StateFlags & win32.DISPLAY_DEVICE_ATTACHED_TO_DESKTOP != 0) {`
`37`	`37`	`const device_name: [:0]const u16 = std.mem.span(@as([*:0]u16, @ptrCast(&display_device.DeviceName)));`
`38`		`- const cloned_device_name = allocator.dupeZ(u16, device_name) catch unreachable;`
`39`		`- adapters.append(cloned_device_name) catch unreachable;`
	`38`	`+ const cloned_device_name = allocator.dupeZ(u16, device_name) catch @panic("OOM");`
	`39`	`+ adapters.append(cloned_device_name) catch @panic("OOM");`
`40`	`40`	`}`
`41`	`41`	`}`
`42`	`42`	`}`
`@@ -62,23 +62,23 @@ pub fn getList() []Monitor {`
`62`	`62`	`var i: u32 = 0;`
`63`	`63`	`while (win32.EnumDisplayDevicesW(adapter, i, &display_device, 0) != 0) : (i += 1) {`
`64`	`64`	`const device_name: [:0]const u16 = std.mem.span(@as([*:0]u16, @ptrCast(&display_device.DeviceName)));`
`65`		`- const cloned_device_name = allocator.dupeZ(u16, device_name) catch unreachable;`
	`65`	`+ const cloned_device_name = allocator.dupeZ(u16, device_name) catch @panic("OOM");`
`66`	`66`	`const device_string: [:0]const u16 = std.mem.span(@as([*:0]u16, @ptrCast(&display_device.DeviceString)));`
`67`		`- const cloned_device_string = std.unicode.utf16LeToUtf8Alloc(allocator, device_string) catch unreachable;`
`68`		`- monitor_names.append(.{ .adapter = adapter, .monitor_name = cloned_device_name, .monitor_friendly_name = cloned_device_string }) catch unreachable;`
	`67`	`+ const cloned_device_string = std.unicode.utf16LeToUtf8Alloc(allocator, device_string) catch @panic("OOM");`
	`68`	`+ monitor_names.append(.{ .adapter = adapter, .monitor_name = cloned_device_name, .monitor_friendly_name = cloned_device_string }) catch @panic("OOM");`
`69`	`69`	`}`
`70`	`70`	`}`
`71`	`71`	`}`
`72`	`72`
`73`	`73`	`for (monitor_names.items) \|name\| {`
`74`	`74`	`monitors.append(Monitor{`
`75`		`- .adapter_win32_name = allocator.dupeZ(u16, name.adapter) catch unreachable,`
`76`		`- .win32_name = allocator.dupeZ(u16, name.monitor_name) catch unreachable,`
`77`		`- .device_name = allocator.dupe(u8, name.monitor_friendly_name) catch unreachable,`
`78`		`- }) catch unreachable;`
	`75`	`+ .adapter_win32_name = allocator.dupeZ(u16, name.adapter) catch @panic("OOM"),`
	`76`	`+ .win32_name = allocator.dupeZ(u16, name.monitor_name) catch @panic("OOM"),`
	`77`	`+ .device_name = allocator.dupe(u8, name.monitor_friendly_name) catch @panic("OOM"),`
	`78`	`+ }) catch @panic("OOM");`
`79`	`79`	`}`
`80`	`80`
`81`		`- monitor_list = monitors.toOwnedSlice() catch unreachable;`
	`81`	`+ monitor_list = monitors.toOwnedSlice() catch @panic("OOM");`
`82`	`82`	`return monitor_list.?;`
`83`	`83`	`}`
`84`	`84`	`}`