wasm

src/target.zig

@@ -19,6 +19,8 @@ pub const TargetConfig = struct {
     linker: ?[]const u8 = null,
     /// Sysroot for cross-compilation (passed as --sysroot to linker).
     sysroot: ?[]const u8 = null,
+    /// Extra flags passed through to the linker (e.g. Emscripten -s flags).
+    extra_link_flags: []const []const u8 = &.{},
 
     pub const OptLevel = enum {
         none,
@@ -51,6 +53,16 @@ pub const TargetConfig = struct {
         return self.tripleContains("windows") or self.tripleContains("win32");
     }
 
+    /// Check if target triple indicates WebAssembly (wasm32 or wasm64).
+    pub fn isWasm(self: TargetConfig) bool {
+        return self.tripleHasPrefix("wasm32", "wasm64");
+    }
+
+    /// Check if target triple indicates Emscripten (contains "emscripten").
+    pub fn isEmscripten(self: TargetConfig) bool {
+        return self.tripleContains("emscripten");
+    }
+
     fn tripleHasPrefix(self: TargetConfig, prefix1: []const u8, prefix2: []const u8) bool {
         if (self.triple) |t| {
             const span = std.mem.span(t);
@@ -139,7 +151,28 @@ pub fn runJITFromObject(obj_buf: c.LLVMMemoryBufferRef) !u8 {
 pub fn link(allocator: std.mem.Allocator, io: std.Io, output_obj: []const u8, extra_objects: []const []const u8, output_bin: []const u8, libraries: []const []const u8, target_config: TargetConfig) !void {
     var argv = std.ArrayList([]const u8).empty;
 
-    if (target_config.isWindows()) {
+    if (target_config.isEmscripten()) {
+        // Emscripten: use emcc as the linker/driver
+        const linker = target_config.linker orelse "emcc";
+        try argv.appendSlice(allocator, &.{ linker, output_obj, "-o", output_bin });
+        for (extra_objects) |eo| try argv.append(allocator, eo);
+
+        if (target_config.sysroot) |sr| {
+            try argv.append(allocator, try std.fmt.allocPrint(allocator, "--sysroot={s}", .{sr}));
+        }
+
+        for (target_config.lib_paths) |lp| {
+            try argv.append(allocator, try std.fmt.allocPrint(allocator, "-L{s}", .{lp}));
+        }
+        for (libraries) |lib| {
+            try argv.append(allocator, try std.fmt.allocPrint(allocator, "-l{s}", .{lib}));
+        }
+
+        // Extra linker flags (e.g. -sUSE_SDL=2, -sUSE_WEBGL2=1, --preload-file)
+        for (target_config.extra_link_flags) |flag| {
+            try argv.append(allocator, flag);
+        }
+    } else if (target_config.isWindows()) {
         // Windows: MSVC-style linker flags
         const linker = target_config.linker orelse "link.exe";
         try argv.appendSlice(allocator, &.{ linker, output_obj });
@@ -176,6 +209,11 @@ pub fn link(allocator: std.mem.Allocator, io: std.Io, output_obj: []const u8, ex
         for (libraries) |lib| {
             try argv.append(allocator, try std.fmt.allocPrint(allocator, "-l{s}", .{lib}));
         }
+
+        // Extra linker flags
+        for (target_config.extra_link_flags) |flag| {
+            try argv.append(allocator, flag);
+        }
     }
 
     const argv_slice = try argv.toOwnedSlice(allocator);