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

[Vladimir Kozlov]

On 4/18/17 2:20 PM, Yuting Chen wrote:
> Hi, are there any comments to this case? I found that the clinit
> method will be compiled if it does not contain the infinite loop. Does
> it mean that clinit will run before it is compiled.

Yes, AOT compiler will run class initializer since it needs to access 
static fields and other values.

Vladimir

>
> Re-paste the bytecode:
>
> 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
> }
>
> On Tue, Apr 18, 2017 at 9:41 AM, Yuting Chen <chenyt.cs.sjtu at gmail.com> wrote:
>> Hi, are there any comments to this case? I found that the clinit
>> method will be compiled if it does not contain the infinite loop. It's
>> weird.
>>
>> 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
>>  }