round

Author: Shachlan

site/source/docs/porting/Debugging.rst

@@ -137,22 +137,22 @@ Debug printouts can even execute arbitrary JavaScript. For example::
   }
 
 
-Printing C++ exception messages
-===============================
+Handling C++ exceptions from javascript
+=======================================
 
 C++ exceptions are thrown from WebAssembly using exception pointers, which means
 that try/catch/finally blocks in JavaScript will only receive a number, which
 represents a pointer into linear memory. In order to get the exception message,
 the user will need to create some WASM code which will extract the meaning from
-the exception. In the example code below we created a function that receives an
-``int`` which is pointer to an ``std::exception``, and by casting the pointer
+the exception. In the example code below we created a function that receives the
+address of a ``std::exception``, and by casting the pointer
 returns the ``what`` function call result.
 
 .. code-block:: cpp
 
   #include <bind.h>
 
-  std::string getExceptionMessage(int exceptionPtr) {
+  std::string getExceptionMessage(intptr_t exceptionPtr) {
     return std::string(reinterpret_cast<std::exception *>(exceptionPtr)->what());
   }
 
@@ -177,9 +177,9 @@ in order to log the thrown exception.
 It's important to notice that this example code will work only for thrown
 statically allocated exceptions. If your code throws other objects, such as
 strings or dynamically allocated exceptions, the handling code will need to
-take that into account. For example, if your code throws either exception
-pointers or strings, the javascript code can handle these situations like
-this:
+take that into account. For example, if your code needs to handle both native
+C++ exceptions and JavaScript exceptions you could use the following code to
+distinguish between them::
 
 .. code-block:: javascript
 
@@ -189,6 +189,7 @@ this:
       : exception;
   }
 
+
 Disabling optimizations
 =======================