Add STAP_ERROR macro

Instead of CONTEXT->last_error = "foo"; goto out; in an embedded-C
function, a newly defined macro STAP_ERROR(str) should be used.
The script can catch the exception with try { } catch { }.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>

diff --git a/translate.cxx b/translate.cxx
index b52f4f154e2879c33c641f076a7c21901e610ba2..f99e0d7aa05462439bd3584d648e5f521a9defb3 100644 (file)
--- a/translate.cxx
+++ b/translate.cxx
@@ -2119,6 +2119,7 @@ c_unparser::emit_function (functiondecl* v)
       o->newline() << retvalue.init();
     }
 
+  o->newline() << "#define STAP_ERROR(...) do { snprintf(CONTEXT->error_buffer, MAXSTRINGLEN, __VA_ARGS__); CONTEXT->last_error = CONTEXT->error_buffer; goto out; } while (0)";
   o->newline() << "#define return goto out"; // redirect embedded-C return
   v->body->visit (this);
   o->newline() << "#undef return";
@@ -2143,6 +2144,7 @@ c_unparser::emit_function (functiondecl* v)
     o->newline() << c_arg_undef(v->locals[i]->name); // #undef STAP_ARG_foo
   }
   o->newline() << "#undef STAP_RETVALUE";
+  o->newline() << "#undef STAP_ERROR";
   o->newline(-1) << "}\n";
 }