Add some optional defines to disable wasm2c trap checks

src/prebuilt/wasm2c.include.c

@@ -1,6 +1,6 @@
 /* Generated from 'wasm2c.c.tmpl' by wasm2c_tmpl.py, do not edit! */
 const char SECTION_NAME(includes)[] =
-"/* Automically generated by wasm2c */\n"
+"/* Automatically generated by wasm2c */\n"
 "#include <math.h>\n"
 "#include <string.h>\n"
 ;
@@ -11,9 +11,13 @@ const char SECTION_NAME(declarations)[] =
 "\n"
 "#define TRAP(x) (wasm_rt_trap(WASM_RT_TRAP_##x), 0)\n"
 "\n"
+"#ifndef WASM_RT_NO_STACK_DEPTH_CHECKS\n"
 "#define FUNC_PROLOGUE                                            \\\n"
 "  if (++wasm_rt_call_stack_depth > WASM_RT_MAX_CALL_STACK_DEPTH) \\\n"
 "    TRAP(EXHAUSTION)\n"
+"#else\n"
+"#define FUNC_PROLOGUE\n"
+"#endif\n"
 "\n"
 "#define FUNC_EPILOGUE --wasm_rt_call_stack_depth\n"
 "\n"
@@ -25,8 +29,12 @@ const char SECTION_NAME(declarations)[] =
 "       ? ((t)table.data[x].func)(__VA_ARGS__)        \\\n"
 "       : TRAP(CALL_INDIRECT))\n"
 "\n"
+"#ifndef WASM_RT_NO_MEMORY_CHECKS\n"
 "#define MEMCHECK(mem, a, t)  \\\n"
 "  if (UNLIKELY((a) + sizeof(t) > mem->size)) TRAP(OOB)\n"
+"#else\n"
+"#define MEMCHECK(mem, a, t)\n"
+"#endif\n"
 "\n"
 "#define DEFINE_LOAD(name, t1, t2, t3)              \\\n"
 "  static inline t3 name(wasm_rt_memory_t* mem, u64 addr) {   \\\n"

src/prebuilt/wasm2c.include.h

@@ -1,6 +1,6 @@
 /* Generated from 'wasm2c.h.tmpl' by wasm2c_tmpl.py, do not edit! */
 const char SECTION_NAME(top)[] =
-"/* Automically generated by wasm2c */\n"
+"/* Automatically generated by wasm2c */\n"
 "#ifdef __cplusplus\n"
 "extern \"C\" {\n"
 "#endif\n"

src/wasm2c.c.tmpl

@@ -1,5 +1,5 @@
 %%includes
-/* Automically generated by wasm2c */
+/* Automatically generated by wasm2c */
 #include <math.h>
 #include <string.h>
 %%declarations
@@ -8,9 +8,13 @@
 
 #define TRAP(x) (wasm_rt_trap(WASM_RT_TRAP_##x), 0)
 
+#ifndef WASM_RT_NO_STACK_DEPTH_CHECKS
 #define FUNC_PROLOGUE                                            \
   if (++wasm_rt_call_stack_depth > WASM_RT_MAX_CALL_STACK_DEPTH) \
     TRAP(EXHAUSTION)
+#else
+#define FUNC_PROLOGUE
+#endif
 
 #define FUNC_EPILOGUE --wasm_rt_call_stack_depth
 
@@ -22,8 +26,12 @@
        ? ((t)table.data[x].func)(__VA_ARGS__)        \
        : TRAP(CALL_INDIRECT))
 
+#ifndef WASM_RT_NO_MEMORY_CHECKS
 #define MEMCHECK(mem, a, t)  \
   if (UNLIKELY((a) + sizeof(t) > mem->size)) TRAP(OOB)
+#else
+#define MEMCHECK(mem, a, t)
+#endif
 
 #define DEFINE_LOAD(name, t1, t2, t3)              \
   static inline t3 name(wasm_rt_memory_t* mem, u64 addr) {   \

src/wasm2c.h.tmpl

@@ -1,5 +1,5 @@
 %%top
-/* Automically generated by wasm2c */
+/* Automatically generated by wasm2c */
 #ifdef __cplusplus
 extern "C" {
 #endif

wasm2c/README.md

@@ -436,3 +436,14 @@ $ wat-desugar fac-flat.wat --fold -o fac-folded.wat
 
 The formatting is different and the variable and function names are gone, but
 the structure is the same.
+
+## Optionally disabling checks
+
+By default wasm2c output will check all the things that WebAssembly VMs would,
+like memory accesses being in bounds. You can optionally disable some of those
+things, by defining the following things when compiling the C code:
+
+* `WASM_RT_NO_MEMORY_CHECKS`: Prevents checks from being emitted for memory
+  accesses being in bounds.
+* `WASM_RT_NO_STACK_DEPTH_CHECKS`: Prevents checks from being emitted for
+  exhausting the stack.

wasm2c/examples/fac/fac.c

@@ -1,4 +1,4 @@
-/* Automically generated by wasm2c */
+/* Automatically generated by wasm2c */
 #include <math.h>
 #include <string.h>
 

wasm2c/examples/fac/fac.h

@@ -1,6 +1,6 @@
 #ifndef FAC_H_GENERATED_
 #define FAC_H_GENERATED_
-/* Automically generated by wasm2c */
+/* Automatically generated by wasm2c */
 #ifdef __cplusplus
 extern "C" {
 #endif