provide __wasm_setjmp/__wasm_setjmp_test for emscripten sjlj as well

also, replace __wasm_longjmp with my version as well.

Author: yamt

system/lib/compiler-rt/emscripten_setjmp.c

@@ -74,40 +74,20 @@ void emscripten_longjmp(uintptr_t env, int val) {
 #endif
 
 #ifdef __USING_WASM_SJLJ__
-
 struct __WasmLongjmpArgs {
   void *env;
   int val;
 };
-
-thread_local struct __WasmLongjmpArgs __wasm_longjmp_args;
-
-// llvm uses `1` for the __c_longjmp tag.
-// See https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/CodeGen/WasmEHFuncInfo.h
-#define C_LONGJMP 1
-
-// Wasm EH allows us to throw and catch multiple values, but that requires
-// multivalue support in the toolchain, whch is not reliable at the time.
-// TODO Consider switching to throwing two values at the same time later.
-void __wasm_longjmp(void *env, int val) {
-  __wasm_longjmp_args.env = env;
-  /*
-  * C standard:
-  *   The longjmp function cannot cause the setjmp macro to return
-  *   the value 0; if val is 0, the setjmp macro returns the value 1.
-  */
-  if (val == 0) {
-    val = 1;
-  }
-  __wasm_longjmp_args.val = val;
-  __builtin_wasm_throw(C_LONGJMP, &__wasm_longjmp_args);
-}
+#endif
 
 // jmp_buf should have large enough size and alignment to contain
 // this structure.
 struct jmp_buf_impl {
   void* func_invocation_id;
   uint32_t label;
+#ifdef __USING_WASM_SJLJ__
+  struct __WasmLongjmpArgs arg;
+#endif
 };
 
 void __wasm_setjmp(void* env, uint32_t label, void* func_invocation_id) {
@@ -127,4 +107,23 @@ uint32_t __wasm_setjmp_test(void* env, void* func_invocation_id) {
   }
   return 0;
 }
+
+#ifdef __USING_WASM_SJLJ__
+void
+__wasm_longjmp(void *env, int val)
+{
+        struct jmp_buf_impl *jb = env;
+        struct __WasmLongjmpArgs *arg = &jb->arg;
+        /*
+         * C standard says:
+         * The longjmp function cannot cause the setjmp macro to return
+         * the value 0; if val is 0, the setjmp macro returns the value 1.
+         */
+        if (val == 0) {
+                val = 1;
+        }
+        arg->env = env;
+        arg->val = val;
+        __builtin_wasm_throw(1, arg); /* 1 == C_LONGJMP */
+}
 #endif