JS_SetFunctionCallback 编辑

Obsolete since JSAPI 37
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

Sets a callback to be run whenever a JavaScript function is invoked or exited. This lets you trace the execution of code, and is particularly useful for JavaScript tracers and profilers since it works across all run modes (interpreter, method JIT, trace JIT). Using this function may have a significant performance impact. See Function tracing for an example.

Syntax

void
JS_SetFunctionCallback(JSContext *cx, JSFunctionCallback fcb);

Description

JS_SetFunctionCallback sets a C function to be called each time a JavaScript function is invoked or exits.

fcb is a pointer to the C function to call.

Note that debuggers should probably use JS_SetCallHook in preference to this function, because it is invoked when the Javascript stack is guaranteed to be in a consistent state (and therefore it is valid to inspect and modify local variables, generate stack traces, and set breakpoints.)

Callback syntax

typedef void
(* JSFunctionCallback)(const JSFunction *fun,const JSScript *scr,
                       const JSContext *cx, int entering);

See Also

See Also

• MXR ID Search for JS_SetFunctionCallback
• Function tracing
• JS_GetFunctionCallback
• bug 1103269