aot compiler halts when there exists an infinite loop in clinit()

[Ioi Lam]

Does AOT run the class initializers during compilation? What if the class initializer has undesirable side effects such as calling System.exit or delete files in the current directory, etc?

Ioi

> Vladimir Kozlov <vladimir.kozlov at oracle.com> 於 2017年4月20日 上午12:59 寫道：
> 
> Graal do report it in some cases (JDK-8178796):
> 
> Error: Failed compilation: compiler.calls.common.InvokeSpecial.caller()V: org.graalvm.compiler.common.RetryableBailoutException: Compilation exceeded 300 seconds during CFG traversal
> 
> But timeout in <clinit> may be hard to catch since it is done in JVM runtime and not in compiler.
> 
> Also I don't know if we should spend time on your case. If an application depends on such class it will never be able to execute. Should we care about such case?
> 
> Vladimir
> 
>> On 4/19/17 9:47 AM, Yuting Chen wrote:
>> The compiler can itself be a jvm, :)
>> 
>> I'd expect that some timeout messages will be reported (a quick
>> patch?). I compiled some pieces of bytecode and waited for the whole
>> night...
>> 
>> Regards,
>> Yuting
>> 
>>> On Wed, Apr 19, 2017 at 2:23 AM, Peter Levart <peter.levart at gmail.com> wrote:
>>> <joke-mode>
>>> Assuming your hunch is correct, I would call this a feature, not a bug.
>>> Isn't it better when compilation of a program loops infinitely than when the
>>> program loops infinitely at runtime? :-)
>>> </joke-mode>
>>> 
>>> Regards, Peter
>>> 
>>> 
>>>> On 04/18/2017 03:14 AM, Yuting Chen wrote:
>>>> 
>>>> Hi, I recently met a problem: when I tried to compile a class whose
>>>> clinit method contains an infinite loop, the aotc waits and fails to
>>>> response....
>>>> 
>>>> It seems that the aotc performs some static analysis before the
>>>> compilation, while the analysis may not stop (when an infinite loop is
>>>> there).
>>>> 
>>>> The bytecode is shown as follows:
>>>> 
>>>> public class Vector1
>>>>   minor version: 0
>>>>   major version: 52
>>>>   flags: ACC_PUBLIC, ACC_SUPER
>>>> Constant pool:
>>>>    #1 = Utf8               Vector1
>>>>    #2 = Class              #1             // Vector1
>>>>    #3 = Utf8               java/lang/Object
>>>>    #4 = Class              #3             // java/lang/Object
>>>>    #5 = Utf8               serialVersionUID
>>>>    #6 = Utf8               J
>>>>    #7 = Long               -2767605614048989439l
>>>>    #9 = Utf8               <clinit>
>>>>   #10 = Utf8               ()V
>>>>   #11 = NameAndType        #5:#6          // serialVersionUID:J
>>>>   #12 = Fieldref           #2.#11         // Vector1.serialVersionUID:J
>>>>   #13 = Utf8               main
>>>>   #14 = Utf8               ([Ljava/lang/String;)V
>>>>   #15 = Utf8               ConstantValue
>>>>   #16 = Utf8               Code
>>>>   #17 = Utf8               StackMapTable
>>>> {
>>>>   public static {};
>>>>     descriptor: ()V
>>>>     flags: ACC_PUBLIC, ACC_STATIC
>>>>     Code:
>>>>       stack=2, locals=0, args_size=0
>>>>          0: ldc2_w        #7                  // long
>>>> -2767605614048989439l
>>>>          3: putstatic     #12                 // Field serialVersionUID:J
>>>>          6: iconst_1
>>>>          7: iconst_m1
>>>>          8: iadd
>>>>          9: ifge          0
>>>>         12: return
>>>>       StackMapTable: number_of_entries = 1
>>>>         frame_type = 0 /* same */
>>>> 
>>>>   public static void main(java.lang.String[]);
>>>>     descriptor: ([Ljava/lang/String;)V
>>>>     flags: ACC_PUBLIC, ACC_STATIC
>>>>     Code:
>>>>       stack=0, locals=1, args_size=1
>>>>          0: return
>>>> }
>>> 
>>>