freetype port: add variant for standardized Wasm EH (WASM_LEGACY_EXCEPTIONS=0)

test/test_freetype_exc.cpp

@@ -0,0 +1,31 @@
+/*
+ * Minimal test that links FreeType and exercises C++ exception handling.
+ * When the freetype port is built with legacy EH but the application uses
+ * standardized Wasm EH (-sWASM_LEGACY_EXCEPTIONS=0), the resulting .wasm
+ * contains a mix of legacy and new EH instructions and fails at
+ * instantiation time.
+ */
+#include <cstdio>
+#include <stdexcept>
+#include <ft2build.h>
+#include FT_FREETYPE_H
+
+int main() {
+  // Exercise C++ exception handling so that new-EH instructions are emitted.
+  try {
+    throw std::runtime_error("test");
+  } catch (const std::exception& e) {
+    printf("caught: %s\n", e.what());
+  }
+
+  // Also call into FreeType so it is actually linked.
+  FT_Library library;
+  FT_Error error = FT_Init_FreeType(&library);
+  if (error) {
+    printf("FT_Init_FreeType failed: %d\n", error);
+    return 1;
+  }
+  printf("FreeType initialized successfully\n");
+  FT_Done_FreeType(library);
+  return 0;
+}

test/test_other.py

@@ -2632,6 +2632,39 @@ def test_freetype_with_pthreads(self):
     # Verify that freetype supports compilation requiring pthreads
     self.emcc('test_freetype.c', ['-pthread', '-sUSE_FREETYPE', '-o', 'a.out.js'])
 
+  @requires_network
+  def test_freetype_wasm_eh(self):
+    # Verify that the freetype port selects the correct new-EH variant
+    # (libfreetype-wasmsjlj.a) when using standardized Wasm EH combined with
+    # SUPPORT_LONGJMP=wasm.  Without the new-EH variant the port falls back to
+    # libfreetype-legacysjlj.a which is built with legacy EH instructions,
+    # causing "module uses a mix of legacy and new exception handling
+    # instructions" at instantiation time in browsers.
+    # Node.js with --experimental-wasm-exnref tolerates mixed EH, so we
+    # verify correctness by checking the cached library name and also
+    # confirming the program runs.
+    self.require_wasm_eh()
+
+    # Build with -v and capture stderr to verify the correct variant is used.
+    proc = self.run_process([
+      EMCC, '-v',
+      test_file('test_freetype_exc.cpp'),
+      '-fwasm-exceptions',
+      '-sUSE_FREETYPE',
+      '-sSUPPORT_LONGJMP=wasm',
+      '-sWASM_LEGACY_EXCEPTIONS=0',
+      '-o', 'test_out.js',
+    ], stderr=PIPE)
+    self.assertContained('libfreetype-wasmsjlj', proc.stderr)
+    self.assertNotContained('libfreetype-legacysjlj', proc.stderr)
+
+    # Also verify the program actually runs.
+    self.do_runf('test_freetype_exc.cpp', 'caught: test\nFreeType initialized successfully\n', cflags=[
+      '-fwasm-exceptions',
+      '-sUSE_FREETYPE',
+      '-sSUPPORT_LONGJMP=wasm',
+    ])
+
   @requires_network
   def test_icu(self):
     self.set_setting('USE_ICU')

tools/ports/freetype.py

@@ -10,7 +10,10 @@
 PKG_VERSION = '26.2.20'
 HASH = 'ce413487c24e689631d705f53b64725256f89fffe9aade7cf07bbd785a9cd49eb6b8d2297a55554f3fee0a50b17e8af78f505cdab565768afab833794f968c2f'
 
-variants = {'freetype-legacysjlj': {'SUPPORT_LONGJMP': 'wasm', 'WASM_LEGACY_EXCEPTIONS': 1}}
+variants = {
+    'freetype-legacysjlj': {'SUPPORT_LONGJMP': 'wasm', 'WASM_LEGACY_EXCEPTIONS': 1},
+    'freetype-wasmsjlj':   {'SUPPORT_LONGJMP': 'wasm', 'WASM_LEGACY_EXCEPTIONS': 0},
+}
 deps = ['zlib']
 
 
@@ -20,7 +23,10 @@ def needed(settings):
 
 def get_lib_name(settings):
   if settings.SUPPORT_LONGJMP == 'wasm':
-    return 'libfreetype-legacysjlj.a'
+    if settings.WASM_LEGACY_EXCEPTIONS:
+      return 'libfreetype-legacysjlj.a'
+    else:
+      return 'libfreetype-wasmsjlj.a'
   else:
     return 'libfreetype.a'
 
@@ -97,6 +103,9 @@ def create(final):
 
     if settings.SUPPORT_LONGJMP == 'wasm':
       flags.append('-sSUPPORT_LONGJMP=wasm')
+      if not settings.WASM_LEGACY_EXCEPTIONS:
+        flags.append('-fwasm-exceptions')
+        flags.append('-sWASM_LEGACY_EXCEPTIONS=0')
 
     ports.make_pkg_config('freetype2', PKG_VERSION, '-sUSE_FREETYPE')
     ports.build_port(source_path, final, 'freetype', flags=flags, srcs=srcs)