Merge pull request #1324 from mitchellh/libghostty-linux

libghostty: support build on Linux

.github/workflows/test.yml

@@ -40,6 +40,25 @@ jobs:
       - name: Test Build
         run: nix develop -c zig build -Dstatic=true -Dapp-runtime=glfw -Dtarget=${{ matrix.target }}
 
+  build-linux-libghostty:
+    runs-on: ubuntu-latest
+    needs: test
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      # Install Nix and use that to run our tests so our environment matches exactly.
+      - uses: cachix/install-nix-action@v24
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
+      - uses: cachix/cachix-action@v14
+        with:
+          name: ghostty
+          authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"
+
+      - name: Build Libghostty
+        run: nix develop -c zig build -Dapp-runtime=none
+
   build-nix:
     runs-on: ubuntu-latest
     needs: test

build.zig

@@ -405,7 +405,7 @@ pub fn build(b: *std.Build) !void {
     }
 
     // App (Linux)
-    if (target.result.os.tag == .linux) {
+    if (target.result.os.tag == .linux and config.app_runtime != .none) {
         // https://developer.gnome.org/documentation/guidelines/maintainer/integrating.html
 
         // Desktop file so that we have an icon and other metadata
@@ -428,6 +428,52 @@ pub fn build(b: *std.Build) !void {
         b.installFile("images/icons/icon_256x256@2x@2x.png", "share/icons/hicolor/256x256@2/apps/com.mitchellh.ghostty.png");
     }
 
+    // libghostty (non-Darwin)
+    if (!builtin.target.isDarwin() and config.app_runtime == .none) {
+        // Shared
+        {
+            const lib = b.addSharedLibrary(.{
+                .name = "ghostty",
+                .root_source_file = .{ .path = "src/main_c.zig" },
+                .optimize = optimize,
+                .target = target,
+            });
+            lib.root_module.addOptions("build_options", exe_options);
+            _ = try addDeps(b, lib, config);
+
+            const lib_install = b.addInstallLibFile(
+                lib.getEmittedBin(),
+                "libghostty.so",
+            );
+            b.getInstallStep().dependOn(&lib_install.step);
+        }
+
+        // Static
+        {
+            const lib = b.addStaticLibrary(.{
+                .name = "ghostty",
+                .root_source_file = .{ .path = "src/main_c.zig" },
+                .optimize = optimize,
+                .target = target,
+            });
+            lib.root_module.addOptions("build_options", exe_options);
+            _ = try addDeps(b, lib, config);
+
+            const lib_install = b.addInstallLibFile(
+                lib.getEmittedBin(),
+                "libghostty.a",
+            );
+            b.getInstallStep().dependOn(&lib_install.step);
+        }
+
+        // Copy our ghostty.h to include.
+        const header_install = b.addInstallHeaderFile(
+            "include/ghostty.h",
+            "ghostty.h",
+        );
+        b.getInstallStep().dependOn(&header_install.step);
+    }
+
     // On Mac we can build the embedding library. This only handles the macOS lib.
     if (builtin.target.isDarwin() and target.result.os.tag == .macos) {
         // Create the universal macOS lib.

include/ghostty.h

@@ -30,6 +30,11 @@ typedef void *ghostty_surface_t;
 typedef void *ghostty_inspector_t;
 
 // Enums are up top so we can reference them later.
+typedef enum {
+    GHOSTTY_PLATFORM_INVALID,
+    GHOSTTY_PLATFORM_MACOS,
+} ghostty_platform_e;
+
 typedef enum {
     GHOSTTY_CLIPBOARD_STANDARD,
     GHOSTTY_CLIPBOARD_SELECTION,
@@ -350,8 +355,17 @@ typedef struct {
 } ghostty_error_s;
 
 typedef struct {
-    void *userdata;
     void *nsview;
+} ghostty_platform_macos_s;
+
+typedef union {
+    ghostty_platform_macos_s macos;
+} ghostty_platform_u;
+
+typedef struct {
+    ghostty_platform_e platform_tag;
+    ghostty_platform_u platform;
+    void *userdata;
     double scale_factor;
     uint16_t font_size;
     const char *working_directory;
@@ -472,9 +486,6 @@ uintptr_t ghostty_surface_pwd(ghostty_surface_t, char *, uintptr_t);
 
 ghostty_inspector_t ghostty_surface_inspector(ghostty_surface_t);
 void ghostty_inspector_free(ghostty_surface_t);
-bool ghostty_inspector_metal_init(ghostty_inspector_t, void *);
-void ghostty_inspector_metal_render(ghostty_inspector_t, void *, void *);
-bool ghostty_inspector_metal_shutdown(ghostty_inspector_t);
 void ghostty_inspector_set_focus(ghostty_inspector_t, bool);
 void ghostty_inspector_set_content_scale(ghostty_inspector_t, double, double);
 void ghostty_inspector_set_size(ghostty_inspector_t, uint32_t, uint32_t);
@@ -484,6 +495,12 @@ void ghostty_inspector_mouse_scroll(ghostty_inspector_t, double, double, ghostty
 void ghostty_inspector_key(ghostty_inspector_t, ghostty_input_action_e, ghostty_input_key_e, ghostty_input_mods_e);
 void ghostty_inspector_text(ghostty_inspector_t, const char *);
 
+#ifdef __APPLE__
+bool ghostty_inspector_metal_init(ghostty_inspector_t, void *);
+void ghostty_inspector_metal_render(ghostty_inspector_t, void *, void *);
+bool ghostty_inspector_metal_shutdown(ghostty_inspector_t);
+#endif
+
 // APIs I'd like to get rid of eventually but are still needed for now.
 // Don't use these unless you know what you're doing.
 void ghostty_set_window_background_blur(ghostty_surface_t, void *);

macos/Sources/Ghostty/SurfaceView.swift

@@ -277,8 +277,11 @@ extension Ghostty {
         /// in the returned struct is only valid as long as this struct is retained.
         func ghosttyConfig(view: SurfaceView) -> ghostty_surface_config_s {
             var config = ghostty_surface_config_new()
+            config.platform_tag = GHOSTTY_PLATFORM_MACOS
+            config.platform = ghostty_platform_u(macos: ghostty_platform_macos_s(
+                nsview: Unmanaged.passUnretained(view).toOpaque()
+            ))
             config.userdata = Unmanaged.passUnretained(view).toOpaque()
-            config.nsview = Unmanaged.passUnretained(view).toOpaque()
             config.scale_factor = NSScreen.main!.backingScaleFactor
 
             if let fontSize = fontSize { config.font_size = fontSize }

src/apprt/embedded.zig

@@ -231,9 +231,49 @@ pub const App = struct {
     }
 };
 
+/// Platform-specific configuration for libghostty.
+pub const Platform = union(PlatformTag) {
+    macos: MacOS,
+
+    // If our build target for libghostty is not darwin then we do
+    // not include macos support at all.
+    pub const MacOS = if (builtin.target.isDarwin()) struct {
+        /// The view to render the surface on.
+        nsview: objc.Object,
+    } else void;
+
+    // The C ABI compatible version of this union. The tag is expected
+    // to be stored elsewhere.
+    pub const C = extern union {
+        macos: extern struct {
+            nsview: ?*anyopaque,
+        },
+    };
+
+    /// Initialize a Platform a tag and configuration from the C ABI.
+    pub fn init(tag_int: c_int, c_platform: C) !Platform {
+        const tag = try std.meta.intToEnum(PlatformTag, tag_int);
+        return switch (tag) {
+            .macos => if (MacOS != void) macos: {
+                const config = c_platform.macos;
+                const nsview = objc.Object.fromId(config.nsview orelse
+                    break :macos error.NSViewMustBeSet);
+                break :macos .{ .macos = .{ .nsview = nsview } };
+            } else error.UnsupportedPlatform,
+        };
+    }
+};
+
+pub const PlatformTag = enum(c_int) {
+    // "0" is reserved for invalid so we can detect unset values
+    // from the C API.
+
+    macos = 1,
+};
+
 pub const Surface = struct {
     app: *App,
-    nsview: objc.Object,
+    platform: Platform,
     core_surface: CoreSurface,
     content_scale: apprt.ContentScale,
     size: apprt.SurfaceSize,
@@ -243,12 +283,14 @@ pub const Surface = struct {
     inspector: ?*Inspector = null,
 
     pub const Options = extern struct {
+        /// The platform that this surface is being initialized for and
+        /// the associated platform-specific configuration.
+        platform_tag: c_int = 0,
+        platform: Platform.C = undefined,
+
         /// Userdata passed to some of the callbacks.
         userdata: ?*anyopaque = null,
 
-        /// The pointer to the backing NSView for the surface.
-        nsview: ?*anyopaque = null,
-
         /// The scale factor of the screen.
         scale_factor: f64 = 1,
 
@@ -279,13 +321,10 @@ pub const Surface = struct {
     };
 
     pub fn init(self: *Surface, app: *App, opts: Options) !void {
-        const nsview = objc.Object.fromId(opts.nsview orelse
-            return error.NSViewMustBeSet);
-
         self.* = .{
             .app = app,
+            .platform = try Platform.init(opts.platform_tag, opts.platform),
             .core_surface = undefined,
-            .nsview = nsview,
             .content_scale = .{
                 .x = @floatCast(opts.scale_factor),
                 .y = @floatCast(opts.scale_factor),
@@ -1584,30 +1623,33 @@ pub const CAPI = struct {
         ptr.freeInspector();
     }
 
-    export fn ghostty_inspector_metal_init(ptr: *Inspector, device: objc.c.id) bool {
-        return ptr.initMetal(objc.Object.fromId(device));
-    }
-
-    export fn ghostty_inspector_metal_render(
-        ptr: *Inspector,
-        command_buffer: objc.c.id,
-        descriptor: objc.c.id,
-    ) void {
-        return ptr.renderMetal(
-            objc.Object.fromId(command_buffer),
-            objc.Object.fromId(descriptor),
-        ) catch |err| {
-            log.err("error rendering inspector err={}", .{err});
-            return;
-        };
-    }
-
-    export fn ghostty_inspector_metal_shutdown(ptr: *Inspector) void {
-        if (ptr.backend) |v| {
-            v.deinit();
-            ptr.backend = null;
+    // Inspector Metal APIs are only available on Apple systems
+    usingnamespace if (builtin.target.isDarwin()) struct {
+        export fn ghostty_inspector_metal_init(ptr: *Inspector, device: objc.c.id) bool {
+            return ptr.initMetal(objc.Object.fromId(device));
         }
-    }
+
+        export fn ghostty_inspector_metal_render(
+            ptr: *Inspector,
+            command_buffer: objc.c.id,
+            descriptor: objc.c.id,
+        ) void {
+            return ptr.renderMetal(
+                objc.Object.fromId(command_buffer),
+                objc.Object.fromId(descriptor),
+            ) catch |err| {
+                log.err("error rendering inspector err={}", .{err});
+                return;
+            };
+        }
+
+        export fn ghostty_inspector_metal_shutdown(ptr: *Inspector) void {
+            if (ptr.backend) |v| {
+                v.deinit();
+                ptr.backend = null;
+            }
+        }
+    } else struct {};
 
     export fn ghostty_inspector_set_size(ptr: *Inspector, w: u32, h: u32) void {
         ptr.updateSize(w, h);

src/renderer/Metal.zig

@@ -466,7 +466,9 @@ pub fn finalizeSurfaceInit(self: *const Metal, surface: *apprt.Surface) !void {
         },
 
         apprt.embedded => .{
-            .view = surface.nsview,
+            .view = switch (surface.platform) {
+                .macos => |v| v.nsview,
+            },
             .scaleFactor = @floatCast(surface.content_scale.x),
         },
 

src/renderer/OpenGL.zig

@@ -422,6 +422,12 @@ pub fn surfaceInit(surface: *apprt.Surface) !void {
         },
 
         apprt.glfw => try self.threadEnter(surface),
+
+        apprt.embedded => {
+            // TODO(mitchellh): this does nothing today to allow libghostty
+            // to compile for OpenGL targets but libghostty is strictly
+            // broken for rendering on this platforms.
+        },
     }
 
     // These are very noisy so this is commented, but easy to uncomment
@@ -529,6 +535,12 @@ pub fn threadEnter(self: *const OpenGL, surface: *apprt.Surface) !void {
                 gl.glad.versionMinor(@intCast(version)),
             });
         },
+
+        apprt.embedded => {
+            // TODO(mitchellh): this does nothing today to allow libghostty
+            // to compile for OpenGL targets but libghostty is strictly
+            // broken for rendering on this platforms.
+        },
     }
 }
 
@@ -548,6 +560,10 @@ pub fn threadExit(self: *const OpenGL) void {
             gl.glad.unload();
             glfw.makeContextCurrent(null);
         },
+
+        apprt.embedded => {
+            // TODO: see threadEnter
+        },
     }
 }
 
@@ -1815,6 +1831,7 @@ pub fn drawFrame(self: *OpenGL, surface: *apprt.Surface) !void {
     switch (apprt.runtime) {
         apprt.glfw => surface.window.swapBuffers(),
         apprt.gtk => {},
+        apprt.embedded => {},
         else => @compileError("unsupported runtime"),
     }
 }