Move PROXY_TO_PTHREAD handling all into native code. NFC

Fixes: #17144

Author: sbc100

src/library_pthread.js

@@ -808,30 +808,6 @@ var LibraryPThread = {
     return 0;
   },
 
-#if PROXY_TO_PTHREAD
-  __call_main__deps: ['exit', '$exitOnMainThread'],
-  __call_main: function(argc, argv) {
-#if !EXIT_RUNTIME
-    // EXIT_RUNTIME==0 set, keeping main thread alive by default.
-    noExitRuntime = true;
-#endif
-    var returnCode = {{{ exportedAsmFunc('_main') }}}(argc, argv);
-#if EXIT_RUNTIME
-    if (!keepRuntimeAlive()) {
-      // exitRuntime enabled, proxied main() finished in a pthread, shut down the process.
-#if PTHREADS_DEBUG
-      err('Proxied main thread finished with return code ' + returnCode + '. EXIT_RUNTIME=1 set, quitting process.');
-#endif
-      exitOnMainThread(returnCode);
-    }
-#else
-#if PTHREADS_DEBUG
-    err('Proxied main thread finished with return code ' + returnCode + '. EXIT_RUNTIME=0 set, so keeping main thread alive for asynchronous event operations.');
-#endif
-#endif
-  },
-#endif
-
   // This function is call by a pthread to signal that exit() was called and
   // that the entire process should exit.
   // This function is always called from a pthread, but is executed on the

system/lib/pthread/emscripten_proxy_main.c

@@ -6,6 +6,7 @@
  */
 
 #include <pthread.h>
+#include <stdlib.h>
 
 #include <emscripten.h>
 #include <emscripten/stack.h>
@@ -14,12 +15,13 @@
 static int _main_argc;
 static char** _main_argv;
 
-extern void __call_main(int argc, char** argv);
+extern int main(int argc, char** argv);
 
 static void* _main_thread(void* param) {
   // This is the main runtime thread for the application.
   emscripten_set_thread_name(pthread_self(), "Application main thread");
-  __call_main(_main_argc, _main_argv);
+  int rtn = main(_main_argc, _main_argv);
+  exit(rtn);
   return NULL;
 }
 

tests/other/metadce/test_metadce_minimal_pthreads.exports

@@ -2,7 +2,7 @@ A
 B
 C
 D
-E
+n
 o
 p
 q

tests/other/metadce/test_metadce_minimal_pthreads.imports

@@ -11,4 +11,3 @@ a.j
 a.k
 a.l
 a.m
-a.n

tests/other/metadce/test_metadce_minimal_pthreads.jssize

@@ -1 +1 @@
-16131
+16079

tests/other/metadce/test_metadce_minimal_pthreads.sent

@@ -11,4 +11,3 @@ j
 k
 l
 m
-n

tests/other/metadce/test_metadce_minimal_pthreads.size

@@ -1 +1 @@
-18310
+18307

tests/test_core.py

@@ -9195,6 +9195,15 @@ def test_pthread_dylink_longjmp(self):
     main = test_file('core/pthread/test_pthread_dylink_longjmp.c')
     self.dylink_testf(main, need_reverse=False)
 
+  @needs_dylink
+  @node_pthreads
+  def test_pthread_dylink_main_module_1(self):
+    self.emcc_args.append('-Wno-experimental')
+    self.set_setting('EXIT_RUNTIME')
+    self.set_setting('USE_PTHREADS')
+    self.set_setting('MAIN_MODULE')
+    self.do_runf(test_file('hello_world.c'))
+
   @needs_dylink
   @node_pthreads
   def test_Module_dynamicLibraries_pthreads(self):

tests/test_other.py

@@ -11416,7 +11416,7 @@ def test_no_main_with_PROXY_TO_PTHREAD(self):
 void foo() {}
 ''')
     err = self.expect_fail([EMCC, 'lib.cpp', '-pthread', '-sPROXY_TO_PTHREAD'])
-    self.assertContained('emcc: error: PROXY_TO_PTHREAD proxies main() for you, but no main exists', err)
+    self.assertContained('error: undefined symbol: main (referenced by top-level compiled C/C++ code)', err)
 
   def test_archive_bad_extension(self):
     # Regression test for https://github.com/emscripten-core/emscripten/issues/14012