我可以让OCaml在未捕获的异常上产生堆栈跟踪吗？

Question

在Java中,当异常转义main()函数时,会向控制台打印堆栈跟踪.你能让OCaml程序做同样的事情吗？

Answer 1

是的,用-g编译并设置 OCAMLRUNPARM=b

$ cat exc.ml
let f () : int =
    raise End_of_file

let g () =
    f () + 44

let _ = g()
$ ocamlc -g -o exc exc.ml
$ OCAMLRUNPARAM=b exc
Fatal error: exception End_of_file
Raised at file "exc.ml", line 2, characters 10-21
Called from file "exc.ml", line 5, characters 4-8
Called from file "exc.ml", line 7, characters 8-11

感谢DanielBünzli指出如果编译为本机代码,行为可能会有所不同.这是我在我的系统上看到的内容(Mac OS X 10.9.1,OCaml 4.01.0):

$ ocamlopt -g -o exc exc.ml
$ OCAMLRUNPARAM=b exc
Fatal error: exception End_of_file
Raised by primitive operation at file "exc.ml", line 5, characters 4-8
Called from file "exc.ml", line 7, characters 8-11

如果你关闭内联,事情似乎工作得很好(至少对于这个非常简单的例子):

$ ocamlopt -inline 0 -g -o exc exc.ml
$ OCAMLRUNPARAM=b exc
Fatal error: exception End_of_file
Raised at file "exc.ml", line 2, characters 10-21
Called from file "exc.ml", line 5, characters 4-8
Called from file "exc.ml", line 7, characters 8-11