Remove remaining pthread function from WASM_WORKERS build. NFC

This includes `pthread_self`, which is not valid to call in Wasm
Workers.

Author: sbc100

ChangeLog.md

@@ -23,6 +23,10 @@ See docs/process.md for more on how version tagging works.
 - The deprecated `EMSCRIPTEN` macro is now defined in `emscripten.h` rather than
   on the command line (`__EMSCRIPTEN__`, which is built into LLVM, should be
   used instead). (#26417)
+- All pthread functions are now undefined when building with `-sWASM_WORKERS`.
+  This is an extension of #26336 which removed many of them.  These APIs were
+  not previously functional under Wasm Workers, but if there is strong use case
+  it may be possible to enable them in future. (#26487)
 
 5.0.3 - 03/14/26
 ----------------

system/include/emscripten/val.h

@@ -566,9 +566,11 @@ class EMBIND_VISIBILITY_DEFAULT val {
 
 private:
   // takes ownership, assumes handle already incref'd and lives on the same thread
-  explicit val(EM_VAL handle)
-      : handle(handle), thread(pthread_self())
-  {}
+  explicit val(EM_VAL handle) :
+#ifdef _REENTRANT
+    thread(pthread_self()),
+#endif
+    handle(handle) {}
 
   // Whether this value is a uses incref/decref (true) or is a special reserved
   // value (false).

system/lib/pthread/emscripten_thread_state.S

@@ -6,8 +6,10 @@
 
 .section .globals,"",@
 
+#ifndef __EMSCRIPTEN_WASM_WORKERS__
 .globaltype thread_ptr, PTR
 thread_ptr:
+#endif
 
 .globaltype is_main_thread, i32
 is_main_thread:
@@ -28,8 +30,10 @@ done_init:
 .globl __set_thread_state
 __set_thread_state:
   .functype __set_thread_state (PTR, i32, i32, i32) -> ()
+#ifndef __EMSCRIPTEN_WASM_WORKERS__
   local.get 0
   global.set thread_ptr
+#endif
   local.get 1
   global.set is_main_thread
   local.get 2
@@ -56,14 +60,13 @@ lazy_init_thread_state:
   end_function
 #endif
 
+#ifndef __EMSCRIPTEN_WASM_WORKERS__
 .globl __get_tp
 __get_tp:
   .functype __get_tp () -> (PTR)
-#if __EMSCRIPTEN_WASM_WORKERS__
-  call lazy_init_thread_state
-#endif
   global.get thread_ptr
   end_function
+#endif
 
 # Semantically the same as testing "!ENVIRONMENT_IS_PTHREAD" in JS
 .globl emscripten_is_main_runtime_thread

tools/system_libs.py

@@ -1215,53 +1215,6 @@ def get_files(self):
         ])
     else:
       ignore += ['thread']
-      libc_files += files_in_path(
-        path='system/lib/libc/musl/src/thread',
-        filenames=[
-          'pthread_self.c',
-          'pthread_cleanup_push.c',
-          'pthread_attr_init.c',
-          'pthread_attr_destroy.c',
-          'pthread_attr_get.c',
-          'pthread_attr_setdetachstate.c',
-          'pthread_attr_setguardsize.c',
-          'pthread_attr_setinheritsched.c',
-          'pthread_attr_setschedparam.c',
-          'pthread_attr_setschedpolicy.c',
-          'pthread_attr_setscope.c',
-          'pthread_attr_setstack.c',
-          'pthread_attr_setstacksize.c',
-          'pthread_getattr_np.c',
-          'pthread_getconcurrency.c',
-          'pthread_getcpuclockid.c',
-          'pthread_getschedparam.c',
-          'pthread_setschedprio.c',
-          'pthread_setconcurrency.c',
-          'default_attr.c',
-          # C11 thread library functions
-          'call_once.c',
-          'tss_create.c',
-          'tss_delete.c',
-          'tss_set.c',
-          'cnd_broadcast.c',
-          'cnd_destroy.c',
-          'cnd_init.c',
-          'cnd_signal.c',
-          'cnd_timedwait.c',
-          'cnd_wait.c',
-          'mtx_destroy.c',
-          'mtx_init.c',
-          'mtx_lock.c',
-          'mtx_timedlock.c',
-          'mtx_trylock.c',
-          'mtx_unlock.c',
-          'thrd_create.c',
-          'thrd_exit.c',
-          'thrd_join.c',
-          'thrd_sleep.c',
-          'thrd_yield.c',
-        ])
-
       libc_files += files_in_path(
         path='system/lib/libc',
         filenames=['emscripten_yield_stub.c'])
@@ -1286,6 +1239,52 @@ def get_files(self):
             'pthread_self_stub.c',
             'proxying_stub.c',
           ])
+        libc_files += files_in_path(
+          path='system/lib/libc/musl/src/thread',
+          filenames=[
+            'pthread_self.c',
+            'pthread_cleanup_push.c',
+            'pthread_attr_init.c',
+            'pthread_attr_destroy.c',
+            'pthread_attr_get.c',
+            'pthread_attr_setdetachstate.c',
+            'pthread_attr_setguardsize.c',
+            'pthread_attr_setinheritsched.c',
+            'pthread_attr_setschedparam.c',
+            'pthread_attr_setschedpolicy.c',
+            'pthread_attr_setscope.c',
+            'pthread_attr_setstack.c',
+            'pthread_attr_setstacksize.c',
+            'pthread_getattr_np.c',
+            'pthread_getconcurrency.c',
+            'pthread_getcpuclockid.c',
+            'pthread_getschedparam.c',
+            'pthread_setschedprio.c',
+            'pthread_setconcurrency.c',
+            'default_attr.c',
+            # C11 thread library functions
+            'call_once.c',
+            'tss_create.c',
+            'tss_delete.c',
+            'tss_set.c',
+            'cnd_broadcast.c',
+            'cnd_destroy.c',
+            'cnd_init.c',
+            'cnd_signal.c',
+            'cnd_timedwait.c',
+            'cnd_wait.c',
+            'mtx_destroy.c',
+            'mtx_init.c',
+            'mtx_lock.c',
+            'mtx_timedlock.c',
+            'mtx_trylock.c',
+            'mtx_unlock.c',
+            'thrd_create.c',
+            'thrd_exit.c',
+            'thrd_join.c',
+            'thrd_sleep.c',
+            'thrd_yield.c',
+          ])
 
     if self.is_mt or self.is_ww:
       # Low level thread primitives available in both pthreads and wasm workers builds.