diff --git a/scripts/genie.lua b/scripts/genie.lua
index aea60a45cc5..346ff439db8 100644
--- a/scripts/genie.lua
+++ b/scripts/genie.lua
@@ -1174,6 +1174,7 @@ configuration { "asmjs" }
 	}
 	linkoptions {
 		"-Wl,--start-group",
+		"-s ERROR_ON_MISSING_LIBRARIES=0"
 	}
 	archivesplit_size "20"
 
diff --git a/src/emu/machine.cpp b/src/emu/machine.cpp
index 054b4d9f057..3591dc49a14 100644
--- a/src/emu/machine.cpp
+++ b/src/emu/machine.cpp
@@ -88,7 +88,7 @@
 #include <rapidjson/writer.h>
 #include <rapidjson/stringbuffer.h>
 
-#if defined(EMSCRIPTEN)
+#if defined(__EMSCRIPTEN__)
 #include <emscripten.h>
 #endif
 
@@ -340,7 +340,7 @@ int running_machine::run(bool quiet)
 
 		m_hard_reset_pending = false;
 
-#if defined(EMSCRIPTEN)
+#if defined(__EMSCRIPTEN__)
 		// break out to our async javascript loop and halt
 		emscripten_set_running_machine(this);
 #endif
@@ -1354,7 +1354,7 @@ device_memory_interface::space_config_vector dummy_space_device::memory_space_co
 //  JAVASCRIPT PORT-SPECIFIC
 //**************************************************************************
 
-#if defined(EMSCRIPTEN)
+#if defined(__EMSCRIPTEN__)
 
 running_machine * running_machine::emscripten_running_machine;
 
@@ -1439,4 +1439,4 @@ void running_machine::emscripten_load(const char *name) {
 	emscripten_running_machine->schedule_load(name);
 }
 
-#endif /* defined(EMSCRIPTEN) */
+#endif /* defined(__EMSCRIPTEN__) */
diff --git a/src/emu/machine.h b/src/emu/machine.h
index 88132ef8f2d..2d1c8fe2613 100644
--- a/src/emu/machine.h
+++ b/src/emu/machine.h
@@ -396,7 +396,7 @@ private:
 	// configuration state
 	dummy_space_device m_dummy_space;
 
-#if defined(EMSCRIPTEN)
+#if defined(__EMSCRIPTEN__)
 private:
 	static running_machine *emscripten_running_machine;
 	static void emscripten_main_loop();
diff --git a/src/frontend/mame/ui/ui.cpp b/src/frontend/mame/ui/ui.cpp
index 3a9151f1f2e..ec176328835 100644
--- a/src/frontend/mame/ui/ui.cpp
+++ b/src/frontend/mame/ui/ui.cpp
@@ -311,7 +311,7 @@ void mame_ui_manager::display_startup_screens(bool first_time)
 	if (!first_time || (str > 0 && str < 60*5) || &machine().system() == &GAME_NAME(___empty) || (machine().debug_flags & DEBUG_FLAG_ENABLED) != 0 || video_none)
 		show_gameinfo = show_warnings = show_mandatory_fileman = false;
 
-#if defined(EMSCRIPTEN)
+#if defined(__EMSCRIPTEN__)
 	// also disable for the JavaScript port since the startup screens do not run asynchronously
 	show_gameinfo = show_warnings = false;
 #endif
diff --git a/src/lib/netlist/plib/pconfig.h b/src/lib/netlist/plib/pconfig.h
index 57540f4ba01..4ce5aea4cdb 100644
--- a/src/lib/netlist/plib/pconfig.h
+++ b/src/lib/netlist/plib/pconfig.h
@@ -141,7 +141,7 @@ typedef __int128_t INT128;
 		#define MEMBER_ABI _thiscall
 	#elif defined(__clang__) && defined(__i386__) && defined(_WIN32)
 		#define PHAS_PMF_INTERNAL 0
-	#elif defined(__arm__) || defined(__ARMEL__) || defined(__aarch64__) || defined(__MIPSEL__) || defined(__mips_isa_rev) || defined(__mips64) || defined(EMSCRIPTEN)
+	#elif defined(__arm__) || defined(__ARMEL__) || defined(__aarch64__) || defined(__MIPSEL__) || defined(__mips_isa_rev) || defined(__mips64) || defined(__EMSCRIPTEN__)
 		#define PHAS_PMF_INTERNAL 2
 	#else
 		#define PHAS_PMF_INTERNAL 1
diff --git a/src/lib/netlist/plib/pdynlib.cpp b/src/lib/netlist/plib/pdynlib.cpp
index 0d32bead51d..828096d1b0c 100644
--- a/src/lib/netlist/plib/pdynlib.cpp
+++ b/src/lib/netlist/plib/pdynlib.cpp
@@ -73,7 +73,7 @@ dynlib::dynlib(const pstring &libname)
 	//else
 	//  fprintf(stderr, "win: library <%s> not found!\n", libname.c_str());
 	delete [] buffer;
-#elif defined(EMSCRIPTEN)
+#elif defined(__EMSCRIPTEN__)
 	//no-op
 #else
 	//printf("loading <%s>\n", libname.c_str());
@@ -107,7 +107,7 @@ dynlib::dynlib(const pstring &path, const pstring &libname)
 		//printf("win: library <%s> not found!\n", libname.c_str());
 	}
 	delete [] buffer;
-#elif defined(EMSCRIPTEN)
+#elif defined(__EMSCRIPTEN__)
 	//no-op
 #else
 	//printf("loading <%s>\n", libname.c_str());
diff --git a/src/lib/util/delegate.cpp b/src/lib/util/delegate.cpp
index c50f1cf5d63..7b4ee8df76e 100644
--- a/src/lib/util/delegate.cpp
+++ b/src/lib/util/delegate.cpp
@@ -39,7 +39,7 @@ delegate_mfp::raw_mfp_data delegate_mfp::s_null_mfp = { {0 }};
 
 delegate_generic_function delegate_mfp::convert_to_generic(delegate_generic_class *&object) const
 {
-#if defined(__arm__) || defined(__ARMEL__) || defined(__aarch64__) || defined(__MIPSEL__) || defined(__mips_isa_rev) || defined(__mips64) || defined(EMSCRIPTEN)
+#if defined(__arm__) || defined(__ARMEL__) || defined(__aarch64__) || defined(__MIPSEL__) || defined(__mips_isa_rev) || defined(__mips64) || defined(__EMSCRIPTEN__)
 	if ((m_this_delta & 1) == 0) {
 #if defined(LOG_DELEGATES)
 		printf("Calculated Addr = %08x\n", (uintptr_t)(void*)(m_function));
diff --git a/src/osd/modules/file/posixdir.cpp b/src/osd/modules/file/posixdir.cpp
index be18239ebf5..2a755a513fe 100644
--- a/src/osd/modules/file/posixdir.cpp
+++ b/src/osd/modules/file/posixdir.cpp
@@ -68,7 +68,7 @@ constexpr char PATHSEPCH = '\\';
 constexpr char PATHSEPCH = '/';
 #endif
 
-#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__bsdi__) || defined(__DragonFly__) || defined(EMSCRIPTEN) || defined(__ANDROID__) || defined(WIN32) || defined(SDLMAME_NO64BITIO)
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__bsdi__) || defined(__DragonFly__) || defined(__EMSCRIPTEN__) || defined(__ANDROID__) || defined(WIN32) || defined(SDLMAME_NO64BITIO)
 using sdl_dirent = struct dirent;
 using sdl_stat = struct stat;
 #define sdl_readdir readdir
diff --git a/src/osd/modules/file/posixfile.cpp b/src/osd/modules/file/posixfile.cpp
index 832b6810db4..8c78d28cbd5 100644
--- a/src/osd/modules/file/posixfile.cpp
+++ b/src/osd/modules/file/posixfile.cpp
@@ -93,7 +93,7 @@ public:
 	{
 		ssize_t result;
 
-#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__bsdi__) || defined(__DragonFly__) || defined(EMSCRIPTEN) || defined(__ANDROID__)
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__bsdi__) || defined(__DragonFly__) || defined(__EMSCRIPTEN__) || defined(__ANDROID__)
 		result = ::pread(m_fd, buffer, size_t(count), off_t(std::make_unsigned_t<off_t>(offset)));
 #elif defined(WIN32) || defined(SDLMAME_NO64BITIO)
 		if (lseek(m_fd, off_t(std::make_unsigned_t<off_t>(offset)), SEEK_SET) < 0)
@@ -114,7 +114,7 @@ public:
 	{
 		ssize_t result;
 
-#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__bsdi__) || defined(__DragonFly__) || defined(EMSCRIPTEN) || defined(__ANDROID__)
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__bsdi__) || defined(__DragonFly__) || defined(__EMSCRIPTEN__) || defined(__ANDROID__)
 		result = ::pwrite(m_fd, buffer, size_t(count), off_t(std::make_unsigned_t<off_t>(offset)));
 #elif defined(WIN32) || defined(SDLMAME_NO64BITIO)
 		if (lseek(m_fd, off_t(std::make_unsigned_t<off_t>(offset)), SEEK_SET) < 0)
@@ -135,7 +135,7 @@ public:
 	{
 		int result;
 
-#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__bsdi__) || defined(__DragonFly__) || defined(EMSCRIPTEN) || defined(WIN32) || defined(SDLMAME_NO64BITIO) || defined(__ANDROID__)
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__bsdi__) || defined(__DragonFly__) || defined(__EMSCRIPTEN__) || defined(WIN32) || defined(SDLMAME_NO64BITIO) || defined(__ANDROID__)
 		result = ::ftruncate(m_fd, off_t(std::make_unsigned_t<off_t>(offset)));
 #else
 		result = ::ftruncate64(m_fd, off64_t(offset));
diff --git a/src/osd/modules/file/posixptty.cpp b/src/osd/modules/file/posixptty.cpp
index 4a4bc9d8db9..00aab42cf44 100644
--- a/src/osd/modules/file/posixptty.cpp
+++ b/src/osd/modules/file/posixptty.cpp
@@ -25,7 +25,7 @@
 #elif defined(__NetBSD__) || defined(__OpenBSD__) || defined(__APPLE__)
 #include <termios.h>
 #include <util.h>
-#elif defined(__linux__) || defined(EMSCRIPTEN)
+#elif defined(__linux__) || defined(__EMSCRIPTEN__)
 #include <pty.h>
 #elif defined(__HAIKU__)
 #include <bsd/pty.h>
diff --git a/src/osd/sdl/sdlprefix.h b/src/osd/sdl/sdlprefix.h
index 79f6c81f4dd..0678b3ddba5 100644
--- a/src/osd/sdl/sdlprefix.h
+++ b/src/osd/sdl/sdlprefix.h
@@ -63,7 +63,7 @@
 #define SDLMAME_NO64BITIO 1
 #endif
 
-#if defined(EMSCRIPTEN)
+#if defined(__EMSCRIPTEN__)
 #define SDLMAME_EMSCRIPTEN 1
 #define SDLMAME_NO64BITIO 1
 struct _IO_FILE {};  //_IO_FILE is an opaque type in the emscripten libc which makes clang cranky