Common Language Infrastructure (CLI) Partitions I to VI

1 Reference number ECMA-123:2009 Ecma International 2009 ECMA-335 6th Edition / June 2012 Common Language Infrastructure (CLI) Partitions I to VI COPYRIGHT PROTECTED DOCUMENT Ecma International 2012 Ecma International 2012 i This Ecma Standard has been adopted by the General Assembly of June 2012. "COPYRIGHT NOTICE <2012> Ecma International This document may be copied, published and distributed to others, and cert ain derivative works of it may be prepared, copied, published, and distributed, in whole or in part, provided that the above copyright notice and this Copyright License and Disclaimer are included on all such copies and derivative works. The only derivative works that are permissible under this Copyright License and Disclaimer are: (i) works which incorporate all or portion of this document for the purpose of providing commentary or explanation (such as an annotated version of the document), (ii) works which incorporate all or portion of this document for the purpose of incorporating features that provide accessibility, (iii) translations of this document into languages other than English and into different formats and (iv) works by making use of this specification in standard conformant products by implementing ( by copy and paste wholly or partly) the functionality therein.

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3 " ii Ecma International 2012 Common Language Infrastructure (CLI) Partitions I VI Partition I: Concepts and Architecture Partition II: metadata Definition and Semantics Partition III: CIL Instruction Set Partition IV: Profiles and Libraries Partition V: Binary Formats Partition VI: Annexes Ecma International 2012 iii T a b l e o f C o n t e n t s F o r e w o r d x x i I . 1 S c o p e 1 I . 2 C o n f o r m a n c e 2 I . 3 N o r m a t i v e r e f e r e n c e s 3 I . 4 C o n v e n t i o n s 5 I . 4 . 1 O r g a n i z a t i o n 5 I . 4 . 2 I n f o r m a t i v e t e x t 5 I . 5 T e r m s a n d d e f i n i t i o n s 6 I . 6 O v e r v i e w o f t h e C o m m o n L a n g u a g e I n f r a s t r u c t u r e 9 I.

4 6 . 1 R e l a t i o n s h i p t o t y p e s a f e t y 9 I . 6 . 2 R e l a t i o n s h i p t o m a n a g e d m e t a d a t a - d r i v e n e x e c u t i o n 10 I . 6 . 2 . 1 M a n a g e d c o d e 10 I . 6 . 2 . 2 M a n a g e d d a t a 11 I . 6 . 2 . 3 S u m m a r y 11 I . 7 C o m m o n L a n g u a g e S p e c i f i c a t i o n 12 I . 7 . 1 I n t r o d u c t i o n 12 I . 7 . 2 V i e w s o f C L S c o m p l i a n c e 12 I . 7 . 2 . 1 C L S f r a m e w o r k 12 I . 7 . 2 . 2 C L S c o n s u m e r 13 I . 7 . 2 . 3 C L S e x t e n d e r 13 I . 7 . 3 C L S c o m p l i a n c e 14 I . 7 . 3 . 1 M a r k i n g i t e m s a s C L S - c o m p l i a n t 14 I . 8 C o m m o n T y p e S y s t e m 16 I . 8 . 1 R e l a t i o n s h i p t o o b j e c t - o r i e n t e d p r o g r a m m i n g 19 I . 8 . 2 V a l u e s a n d t y p e s 19 I . 8 . 2 . 1 V a l u e t y p e s a n d r e f e r e n c e t y p e s 19 I.

5 8 . 2 . 2 B u i l t - i n v a l u e a n d r e f e r e n c e t y p e s 20 I . 8 . 2 . 3 C l a s s e s , i n t e r f a c e s , a n d o b j e c t s 21 I . 8 . 2 . 4 B o x i n g a n d u n b o x i n g o f v a l u e s 21 I . 8 . 2 . 5 I d e n t i t y a n d e q u a l i t y o f v a l u e s 22 I . 8 . 3 L o c a t i o n s 23 I . 8 . 3 . 1 A s s i g n m e n t - c o m p a t i b l e l o c a t i o n s 23 I . 8 . 3 . 2 C o e r c i o n 23 iv Ecma International 2012 I . 8 . 3 . 3 C a s t i n g 24 I . 8 . 4 T y p e m e m b e r s 24 I . 8 . 4 . 1 F i e l d s , a r r a y e l e m e n t s , a n d v a l u e s 24 I . 8 . 4 . 2 M e t h o d s 24 I . 8 . 4 . 3 S t a t i c f i e l d s a n d s t a t i c m e t h o d s 25 I.

6 8 . 4 . 4 V i r t u a l m e t h o d s 25 I . 8 . 5 N a m i n g 25 I . 8 . 5 . 1 V a l i d n a m e s 25 I . 8 . 5 . 2 A s s e m b l i e s a n d s c o p i n g 26 I . 8 . 5 . 3 V i s i b i l i t y , a c c e s s i b i l i t y , a n d s e c u r i t y 27 I . 8 . 6 C o n t r a c t s 29 I . 8 . 6 . 1 S i g n a t u r e s 30 I . 8 . 7 A s s i g n m e n t c o m p a t i b i l i t y 34 I . 8 . 7 . 1 A s s i g n m e n t c o m p a t i b i l i t y f o r s i g n a t u r e t y p e s 37 I . 8 . 7 . 2 A s s i g n m e n t c o m p a t i b i l i t y f o r l o c a t i o n t y p e s 38 I . 8 . 7 . 3 G e n e r a l a s s i g n m e n t c o m p a t i b i l i t y 38 I . 8 . 8 T y p e s a f e t y a n d v e r i f i c a t i o n 39 I . 8 . 9 T y p e d e f i n e r s 39 I . 8 . 9 . 1 A r r a y t y p e s 40 I . 8 . 9 . 2 U n m a n a g e d p o i n t e r t y p e s 41 I . 8 . 9 . 3 D e l e g a t e s 41 I . 8 . 9 . 4 I n t e r f a c e t y p e d e f i n i t i o n 42 I.

7 8 . 9 . 5 C l a s s t y p e d e f i n i t i o n 43 I . 8 . 9 . 6 O b j e c t t y p e d e f i n i t i o n s 44 I . 8 . 9 . 7 V a l u e t y p e d e f i n i t i o n 47 I . 8 . 9 . 8 T y p e i n h e r i t a n c e 47 I . 8 . 9 . 9 O b j e c t t y p e i n h e r i t a n c e 47 I . 8 . 9 . 1 0 V a l u e t y p e i n h e r i t a n c e 48 I . 8 . 9 . 1 1 I n t e r f a c e t y p e d e r i v a t i o n 48 I . 8 . 1 0 M e m b e r i n h e r i t a n c e 48 I . 8 . 1 0 . 1 F i e l d i n h e r i t a n c e 48 I . 8 . 1 0 . 2 M e t h o d i n h e r i t a n c e 48 I . 8 . 1 0 . 3 P r o p e r t y a n d e v e n t i n h e r i t a n c e 49 I . 8 . 1 0 . 4 H i d i n g , o v e r r i d i n g , a n d l a y out 49 I . 8 . 1 1 M e m b e r d e f i n i t i o n s 50 I . 8 . 1 1 . 1 M e t h o d d e f i n i t i o n s 50 I . 8 . 1 1 . 2 F i e l d d e f i n i t i o n s 51 I . 8 . 1 1 . 3 P r o p e r t y d e f i n i t i o n s 51 I.

8 8 . 1 1 . 4 E v e n t d e f i n i t i o n s 52 I . 8 . 1 1 . 5 N e s t e d t y p e d e f i n i t i o n s 52 Ecma International 2012 v I . 9 M e t a d a t a 53 I . 9 . 1 C o m p o n e n t s a n d a s s e m b l i e s 53 I . 9 . 2 A c c e s s i n g m e t a d a t a 53 I . 9 . 2 . 1 M e t a d a t a t o k e n s 54 I . 9 . 2 . 2 M e m b e r s i g n a t u r e s i n m e t a d a t a 54 I . 9 . 3 U n m a n a g e d c o d e 54 I . 9 . 4 M e t h o d i m p l e m e n t a t i o n m e t a d a t a 54 I . 9 . 5 C l a s s l a y o u t 55 I . 9 . 6 A s s e m b l i e s : n a m e s c o p e s f o r t y p e s 55 I . 9 . 7 M e t a d a t a e x t e n s i b i l i t y 56 I . 9 . 8 G l o b a l s , i m p o r t s , a n d e x p o r t s 57 I . 9 . 9 S c o p e d s t a t i c s 58 I . 1 0 N a m e a n d t y p e r u l e s f o r t h e C o m m o n L a n g u a g e S p e c i f i c a t i o n 59 I.

9 1 0 . 1 I d e n t i f i e r s 59 I . 1 0 . 2 O v e r l o a d i n g 59 I . 1 0 . 3 O p e r a t o r o v e r l o a d i n g 60 I . 1 0 . 3 . 1 U n a r y o p e r a t o r s 60 I . 1 0 . 3 . 2 B i n a r y o p e r a t o r s 61 I . 1 0 . 3 . 3 C o n v e r s i o n o p e r a t o r s 62 I . 1 0 . 4 N a m i n g p a t t e r n s 62 I . 1 0 . 5 E x c e p t i o n s 63 I . 1 0 . 6 C u s t o m a t t r i b u t e s 63 I . 1 0 . 7 G e n e r i c t y p e s a n d m e t h o d s 64 I . 1 0 . 7 . 1 N e s t e d t y p e p a r a m e t e r r e - d e c l a r a t i o n 64 I . 1 0 . 7 . 2 T y p e n a m e s a n d a r i t y e n c o d i n g 65 I . 1 0 . 7 . 3 T y p e c o n s t r a i n t r e - d e c l a r a t i o n 66 I . 1 0 . 7 . 4 C o n s t r a i n t t y p e r e s t r i c t i o n s 67 I . 1 0 . 7 . 5 F r a m e w o r k s a n d a c c e s s i b i l i t y o f n e s t e d t y p e s 67 I . 1 0 . 7 . 6 F r a m e w o r k s a n d a b s t r a c t o r v i r t u a l m e t h o d s 68 I.

10 1 1 C o l l e c t e d C o m m o n L a n g u a g e S p e c i f i c a t i o n r u l e s 69 I . 1 2 V i r t u a l E x e c u t i o n S y s t e m 72 I . 1 2 . 1 S u p p o r t e d d a t a t y p e s 72 I . 1 2 . 1 . 1 N a t i v e s i z e : n a t i v e i n t , n a t i v e u n s i g n e d i n t , O a n d & 73 I . 1 2 . 1 . 2 H a n d l i n g o f s h o r t i n t e g e r d a t a t y p e s 74 I . 1 2 . 1 . 3 H a n d l i n g o f f l o a t i n g - p o i n t d a t a t y p e s 75 I . 1 2 . 1 . 4 C I L i n s t r u c t i o n s a n d n u m e r i c t y p e s 76 I . 1 2 . 1 . 5 C I L i n s t r u c t i o n s a n d p o i n t e r t y p e s 77 I . 1 2 . 1 . 6 A g g r e g a t e d a t a 78 vi Ecma International 2012 I.