Don't build embind as a library

This is partial revert of #8817.  It turns out that all users of bind.h
have to agree on -fno-rtti.  In particular if a user passed -fno-rtti
to build their code the bind.cpp needs to be compiled with the same
settings.

Perhaps we can find a way to avoid this in the future but for now
it looks like we are stuck compiling bind.cpp on demand at link time.

Fixes: #9122

Author: sbc100

emcc.py

@@ -65,6 +65,7 @@
 C_ENDINGS = C_ENDINGS + SPECIAL_ENDINGLESS_FILENAMES # consider the special endingless filenames like /dev/null to be C
 
 JS_CONTAINING_ENDINGS = ('.js', '.mjs', '.html')
+EXECUTABLE_ENDINGS = JS_CONTAINING_ENDINGS + ('.wasm',)
 BITCODE_ENDINGS = ('.bc', '.o', '.obj', '.lo')
 DYNAMICLIB_ENDINGS = ('.dylib', '.so') # Windows .dll suffix is not included in this list, since those are never linked to directly on the command line.
 STATICLIB_ENDINGS = ('.a',)
@@ -1080,6 +1081,13 @@ def check(input_file):
     # Note the exports the user requested
     shared.Building.user_requested_exports = shared.Settings.EXPORTED_FUNCTIONS[:]
 
+    compile_only = has_dash_c or has_dash_S or final_suffix not in EXECUTABLE_ENDINGS
+
+    # If we are using embind and linking, now is the time to link in bind.cpp
+    if shared.Settings.EMBIND and not compile_only:
+      input_files.append((next_arg_index, shared.path_from_root('system', 'lib', 'embind', 'bind.cpp')))
+      next_arg_index += 1
+
     # -s ASSERTIONS=1 implies the heaviest stack overflow check mode. Set the implication here explicitly to avoid having to
     # do preprocessor "#if defined(ASSERTIONS) || defined(STACK_OVERFLOW_CHECK)" in .js files, which is not supported.
     if shared.Settings.ASSERTIONS:
@@ -1175,7 +1183,7 @@ def check(input_file):
       shared.Settings.WORKAROUND_IOS_9_RIGHT_SHIFT_BUG = 0
       shared.Settings.WORKAROUND_OLD_WEBGL_UNIFORM_UPLOAD_IGNORED_OFFSET_BUG = 0
 
-    if shared.Settings.STB_IMAGE and final_suffix in JS_CONTAINING_ENDINGS:
+    if shared.Settings.STB_IMAGE and not compile_only:
       input_files.append((next_arg_index, shared.path_from_root('third_party', 'stb_image.c')))
       next_arg_index += 1
       shared.Settings.EXPORTED_FUNCTIONS += ['_stbi_load', '_stbi_load_from_memory', '_stbi_image_free']
@@ -1204,9 +1212,6 @@ def check(input_file):
       shared.Settings.EXPORTED_FUNCTIONS += ['___cxa_demangle']
       forced_stdlibs.append('libc++abi')
 
-    if shared.Settings.EMBIND:
-      forced_stdlibs.append('libembind')
-
     if not shared.Settings.ONLY_MY_CODE and not shared.Settings.MINIMAL_RUNTIME:
       # Always need malloc and free to be kept alive and exported, for internal use and other modules
       shared.Settings.EXPORTED_FUNCTIONS += ['_malloc', '_free']
@@ -1884,9 +1889,6 @@ def compile_source_file(i, input_file):
               temp_files[pos] = (temp_files[pos][0], new_temp_file)
 
       # Decide what we will link
-      executable_endings = JS_CONTAINING_ENDINGS + ('.wasm',)
-      compile_only = final_suffix not in executable_endings or has_dash_c or has_dash_S
-
       if compile_only or not shared.Settings.WASM_BACKEND:
         # Filter link flags, keeping only those that shared.Building.link knows
         # how to deal with.  We currently can't handle flags with options (like

tools/system_libs.py

@@ -932,16 +932,6 @@ def get_default_variation(cls, **kwargs):
     )
 
 
-class libembind(CXXLibrary):
-  name = 'libembind'
-  cflags = ['-std=c++11']
-  depends = ['libc++abi']
-  never_force = True
-
-  def get_files(self):
-    return [shared.path_from_root('system', 'lib', 'embind', 'bind.cpp')]
-
-
 class libfetch(CXXLibrary, MTLibrary):
   name = 'libfetch'
   depends = ['libc++abi']