Fix libpng and libfreetype port with wasm exceptions are enabled

For libpng we simply avoid the use of setjmp/longjmp completely.

For libfreetype the use of setjmp/longjmp is not optional so we build a
variant of the library that uses wasm exceptions for setjmp/longjmp
support.

Fixes: #19001

test/test_other.py

@@ -92,6 +92,20 @@ def metafunc(self, wasmfs):
   return metafunc
 
 
+def also_with_wasm_longjmp(f):
+  def metafunc(self, wasmfs):
+    if wasmfs:
+      self.require_wasm_eh()
+      self.emcc_args.append('-sSUPPORT_LONGJMP=wasm')
+      f(self)
+    else:
+      f(self)
+
+  metafunc._parameterize = {'': (False,),
+                            'wasm_longjmp': (True,)}
+  return metafunc
+
+
 def wasmfs_all_backends(f):
   def metafunc(self, backend):
     self.set_setting('WASMFS')
@@ -2205,6 +2219,7 @@ def test_bzip2(self):
     self.do_runf(test_file('bzip2_test.c'), 'usage: unzcrash filename',
                  emcc_args=['-sUSE_BZIP2', '-Wno-pointer-sign'])
 
+  @also_with_wasm_longjmp
   def test_freetype(self):
     # copy the Liberation Sans Bold truetype file located in the
     # <emscripten_root>/test/freetype to the compilation folder

tools/ports/freetype.py

@@ -8,11 +8,20 @@
 TAG = 'version_1'
 HASH = '0d0b1280ba0501ad0a23cf1daa1f86821c722218b59432734d3087a89acd22aabd5c3e5e1269700dcd41e87073046e906060f167c032eb91a3ac8c5808a02783'
 
+variants = {'freetype-wasm-longjmp': {'SUPPORT_LONGJMP': 'wasm'}}
+
 
 def needed(settings):
   return settings.USE_FREETYPE
 
 
+def get_lib_name(settings):
+  if settings.SUPPORT_LONGJMP == 'wasm':
+    return 'libfreetype-wasm-eh.a'
+  else:
+    return 'libfreetype.a'
+
+
 def get(ports, settings, shared):
   ports.fetch_project('freetype', f'https://github.com/emscripten-ports/FreeType/archive/{TAG}.zip', sha512hash=HASH)
 
@@ -90,13 +99,16 @@ def create(final):
       '-pthread'
     ]
 
+    if settings.SUPPORT_LONGJMP == 'wasm':
+      flags.append('-sSUPPORT_LONGJMP=wasm')
+
     ports.build_port(source_path, final, 'freetype', flags=flags, srcs=srcs)
 
-  return [shared.cache.get_lib('libfreetype.a', create, what='port')]
+  return [shared.cache.get_lib(get_lib_name(settings), create, what='port')]
 
 
 def clear(ports, settings, shared):
-  shared.cache.erase_lib('libfreetype.a')
+  shared.cache.erase_lib(get_lib_name(settings))
 
 
 def process_args(ports):

tools/ports/libpng.py

@@ -312,17 +312,17 @@ def show():
 #define PNG_SAVE_INT_32_SUPPORTED
 #define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SEQUENTIAL_READ_SUPPORTED
-#define PNG_SETJMP_SUPPORTED
+/*define PNG_SETJMP_SUPPORTED*/
 #define PNG_SET_OPTION_SUPPORTED
 #define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SET_USER_LIMITS_SUPPORTED
 #define PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
 #define PNG_SIMPLIFIED_READ_BGR_SUPPORTED
-#define PNG_SIMPLIFIED_READ_SUPPORTED
+/*#define PNG_SIMPLIFIED_READ_SUPPORTED*/
 #define PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
 #define PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
 #define PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
-#define PNG_SIMPLIFIED_WRITE_SUPPORTED
+/*#define PNG_SIMPLIFIED_WRITE_SUPPORTED*/
 #define PNG_STDIO_SUPPORTED
 #define PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_TEXT_SUPPORTED