Implemented Traits for PHP as proposed in the RFC [TRAITS]

# RFC http://wiki.php.net/rfc/horizontalreuse#traits_-_reuse_of_behavior
# Ok, here we go, I guess that will result in more discussion, which is fine
# by me. But now, the patch is here, and properly archived.
# 
# See below a list of notes to the patch, it also includes a list of
# points which should be fixed
# 
# Internals of the Traits Patch
# -----------------------------
# 
# Open TODOs
# """"""""""
# 
# - Reflection API
# - support for traits for internal classes
#   - currently destroy_zend_class does not handle that case 
# 
# Introduced Structures
# """""""""""""""""""""
# 
# Data structures to encode the composition information specified in the
# source:
#  - zend_trait_method_reference
#  - zend_trait_precedence
#  - zend_trait_alias
# 
# Changes
# """""""
# 
# zend_class_entry
#  - uses NULL terminated lists of pointers for
#    - trait_aliases
#    - trait_precedences
#    - do you prefer an explicit counter?
#    - the information is only necessary during class composition
#      but might be interesting for reflection
#    - did not want to blow up class further with not really necessary length counters
# 
# added keywords
#   - trait
#   - insteadof
# 
# Added opcodes
#  ZEND_ADD_TRAIT
#    - similar to ZEND_ADD_INTERFACE
#    - adds the trait to the list of traits of a class, no actual composition done
#  ZEND_BIND_TRAITS
#    - emitted in zend_do_end_class_declaration
#    - concludes the class definition and will initiate the trait composition
#      when the class definition is encountered during runtime
# 
# Added Flags
#   ZEND_ACC_TRAIT = 0x120
#   ZEND_ACC_IMPLEMENT_TRAITS = 0x400000
#   ZEND_FETCH_CLASS_TRAIT = 14
# 
# zend_vm_execute.h
#  - not sure whether the handler initialization (ZEND_ADD_TRAIT_SPEC_HANDLER,
#    ZEND_BIND_TRAITS_SPEC_HANDLER) is correct, maybe it should be more selective
# 
# zend_compile.c
#  - refactored do_inherit_method_check
#    split into do_inherit_method_check and do_inheritance_check_on_method
#  - added helper functions use a '_' as prefix and are not mentioned in the
#    headers
#  - _copy_functions
#    prepare hash-maps of functions which should be merged into a class
#    here the aliases are handled
#  - _merge_functions
#    builds a hash-table of the methods which need to be added to a class
#    does the conflict detection
#  - reused php_runkit_function_copy_ctor
#    - it is not identical with the original code anymore, needed to update it
#      think I fixed some bugs, not sure whether all have been reported back to runkit
#    - has to be renamed, left the name for the moment, to make its origin obvious
#    - here might be optimization potential
#    - not sure whether everything needs to be copied
#      - copying the literals might be broken
#        - added it since the literals array is freed by efree and gave problems
#          with doubled frees
#      - all immutable parts of the zend_op array should not be copied
#        - am not sure which parts are immutable
#        - and not sure how to avoid doubled frees on the same arrays on shutdown
#  - _merge_functions_to_class
#    does the final merging with the target class to handle inherited
#    and overridden methods
#  - small helper for NULL terminated lists
#    zend_init_list, zend_add_to_list
# 
# zend_language_parser.y
#  - reused class definition for traits
#    - there should be something with regard to properties
#      - if they get explicitly defined, it might be worthwhile to
#        check that there are no collisions with other traits in a composition
#        (however, I would not introduce elaborate language features to control that
#         but a notice for such conflicts might be nice to the developers)

1 files changed, 43 insertions, 0 deletions

diff --git a/Zend/zend.h b/Zend/zend.h
index 7efa9f4825..c077cb1c53 100644
--- a/Zend/zend.h
+++ b/Zend/zend.h
@@ -420,6 +420,44 @@ struct _zend_unserialize_data;
 typedef struct _zend_serialize_data zend_serialize_data;
 typedef struct _zend_unserialize_data zend_unserialize_data;
 
+struct _zend_trait_method_reference {
+	char* method_name;
+	unsigned int mname_len;
+	
+	zend_class_entry *ce;
+	
+	char* class_name;
+	unsigned int cname_len;
+};
+typedef struct _zend_trait_method_reference	zend_trait_method_reference;
+
+struct _zend_trait_precedence {
+	zend_trait_method_reference *trait_method;
+	
+	zend_class_entry** exclude_from_classes;
+	
+	union _zend_function* function;
+};
+typedef struct _zend_trait_precedence zend_trait_precedence;
+
+struct _zend_trait_alias {
+	zend_trait_method_reference *trait_method;
+	
+	/**
+	* name for method to be added
+	*/
+	char* alias;
+	unsigned int alias_len;
+	
+	/**
+	* modifiers to be set on trait method
+	*/
+	zend_uint modifiers;
+	
+	union _zend_function* function;
+};
+typedef struct _zend_trait_alias zend_trait_alias;
+
 struct _zend_class_entry {
 	char type;
 	char *name;
@@ -464,6 +502,11 @@ struct _zend_class_entry {
 
 	zend_class_entry **interfaces;
 	zend_uint num_interfaces;
+	
+	zend_class_entry **traits;
+	zend_uint num_traits;
+	zend_trait_alias **trait_aliases;
+	zend_trait_precedence **trait_precedences;
 
 	char *filename;
 	zend_uint line_start;