src/share/vm/utilities/accessFlags.hpp

rev 8156 : 8157181: Compilers accept modification of final fields outside initializer methods
Summary: Track initialized final field updates; disable constant folding if an update is detected.
Reviewed-by: vlivanov, dnsimon, forax, never, kvn, coleenp

*** 77,87 ****
    // (e.g., ACC_ENUM).
    // Note that the class-related ACC_ANNOTATION bit conflicts with these flags.
    JVM_ACC_FIELD_ACCESS_WATCHED       = 0x00002000,  // field access is watched by JVMTI
    JVM_ACC_FIELD_MODIFICATION_WATCHED = 0x00008000,  // field modification is watched by JVMTI
    JVM_ACC_FIELD_INTERNAL             = 0x00000400,  // internal field, same as JVM_ACC_ABSTRACT
!   JVM_ACC_FIELD_STABLE               = 0x00000020,  // @Stable field, same as JVM_ACC_SYNCHRONIZED
    JVM_ACC_FIELD_HAS_GENERIC_SIGNATURE = 0x00000800, // field has generic signature
  
    JVM_ACC_FIELD_INTERNAL_FLAGS       = JVM_ACC_FIELD_ACCESS_WATCHED |
                                         JVM_ACC_FIELD_MODIFICATION_WATCHED |
                                         JVM_ACC_FIELD_INTERNAL |
--- 77,88 ----
    // (e.g., ACC_ENUM).
    // Note that the class-related ACC_ANNOTATION bit conflicts with these flags.
    JVM_ACC_FIELD_ACCESS_WATCHED            = 0x00002000, // field access is watched by JVMTI
    JVM_ACC_FIELD_MODIFICATION_WATCHED      = 0x00008000, // field modification is watched by JVMTI
    JVM_ACC_FIELD_INTERNAL                  = 0x00000400, // internal field, same as JVM_ACC_ABSTRACT
!   JVM_ACC_FIELD_STABLE                    = 0x00000020, // @Stable field, same as JVM_ACC_SYNCHRONIZED and JVM_ACC_SUPER
!   JVM_ACC_FIELD_INITIALIZED_FINAL_UPDATE  = 0x00000100, // (static) final field updated outside (class) initializer, same as JVM_ACC_NATIVE
    JVM_ACC_FIELD_HAS_GENERIC_SIGNATURE     = 0x00000800, // field has generic signature
  
    JVM_ACC_FIELD_INTERNAL_FLAGS       = JVM_ACC_FIELD_ACCESS_WATCHED |
                                         JVM_ACC_FIELD_MODIFICATION_WATCHED |
                                         JVM_ACC_FIELD_INTERNAL |
*** 148,157 ****
--- 149,160 ----
  
    // field flags
    bool is_field_access_watched() const  { return (_flags & JVM_ACC_FIELD_ACCESS_WATCHED) != 0; }
    bool is_field_modification_watched() const
                                          { return (_flags & JVM_ACC_FIELD_MODIFICATION_WATCHED) != 0; }
+   bool has_field_initialized_final_update() const
+                                         { return (_flags & JVM_ACC_FIELD_INITIALIZED_FINAL_UPDATE) != 0; }
    bool on_stack() const                 { return (_flags & JVM_ACC_ON_STACK) != 0; }
    bool is_internal() const              { return (_flags & JVM_ACC_FIELD_INTERNAL) != 0; }
    bool is_stable() const                { return (_flags & JVM_ACC_FIELD_STABLE) != 0; }
    bool field_has_generic_signature() const
                                          { return (_flags & JVM_ACC_FIELD_HAS_GENERIC_SIGNATURE) != 0; }
*** 227,236 ****
--- 230,248 ----
                                             atomic_set_bits(JVM_ACC_FIELD_MODIFICATION_WATCHED);
                                           } else {
                                             atomic_clear_bits(JVM_ACC_FIELD_MODIFICATION_WATCHED);
                                           }
                                         }
+ 
+   void set_has_field_initialized_final_update(const bool value) {
+     if (value) {
+       atomic_set_bits(JVM_ACC_FIELD_INITIALIZED_FINAL_UPDATE);
+     } else {
+       atomic_clear_bits(JVM_ACC_FIELD_INITIALIZED_FINAL_UPDATE);
+     }
+   }
+ 
    void set_field_has_generic_signature()
                                         {
                                           atomic_set_bits(JVM_ACC_FIELD_HAS_GENERIC_SIGNATURE);
                                         }