Add mozjs, V8 and WABT setup script (#3053)

Adds a new script `./third_party/setup.py` to conveniently install necessary dependencies for testing and fuzzing, including the SpiderMonkey JS shell (mozjs), the V8 JS shell and WABT. Other scripts now automatically pick these up when installed and fall back to look for the tools in PATH like before.

1 files changed, 65 insertions, 0 deletions

diff --git a/third_party/wabt/wasm2c/wasm-rt-impl.h b/third_party/wabt/wasm2c/wasm-rt-impl.h
new file mode 100644
index 000000000..39d5ed930
--- /dev/null
+++ b/third_party/wabt/wasm2c/wasm-rt-impl.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright 2018 WebAssembly Community Group participants
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef WASM_RT_IMPL_H_
+#define WASM_RT_IMPL_H_
+
+#include <setjmp.h>
+
+#include "wasm-rt.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** A setjmp buffer used for handling traps. */
+extern jmp_buf g_jmp_buf;
+
+/** Saved call stack depth that will be restored in case a trap occurs. */
+extern uint32_t g_saved_call_stack_depth;
+
+#if WASM_RT_MEMCHECK_SIGNAL_HANDLER_POSIX
+#define WASM_RT_SETJMP(buf) sigsetjmp(buf, 1)
+#define WASM_RT_LONGJMP(buf, val) siglongjmp(buf, val)
+#else
+#define WASM_RT_SETJMP(buf) setjmp(buf)
+#define WASM_RT_LONGJMP(buf, val) longjmp(buf, val)
+#endif
+
+/** Convenience macro to use before calling a wasm function. On first execution
+ * it will return `WASM_RT_TRAP_NONE` (i.e. 0). If the function traps, it will
+ * jump back and return the trap that occurred.
+ *
+ * ```
+ *   wasm_rt_trap_t code = wasm_rt_impl_try();
+ *   if (code != 0) {
+ *     printf("A trap occurred with code: %d\n", code);
+ *     ...
+ *   }
+ *
+ *   // Call the potentially-trapping function.
+ *   my_wasm_func();
+ * ```
+ */
+#define wasm_rt_impl_try()                              \
+  (g_saved_call_stack_depth = wasm_rt_call_stack_depth, \
+   WASM_RT_SETJMP(g_jmp_buf))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // WASM_RT_IMPL_H_