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Text File | 1995-12-05 | 65KB | 2,481 lines

\ High-level class/object implementation. cr .( loading Class...) \ Note that the object header format is documented at "object building" \ below. \ June 91 mrh Moved indexed methods from Object to Indexed-obj in Struct. \ Added BIND_WITH. \ May 92 mrh Added [] as synonym for ** \ Apr 94 mrh (Mops 2.5) Added several features: \ Naming of ivars pushing their address. \ Temp (local) objects \ record{ ... } replacing general/non-general distinction. \ classinit: now sent to all superclasses. \ msg: super> aSuper \ Feb 95 mrh Added static and public ivars. \ Apr 95 mrh Allowed static ivars to also be public. Added class_as>. \ You want documentation? Here you are!! \ Here are all our various class/object formats: (* ================= Object header ====================== Note if the obj is an ivar, it doesn't have a header if it's in a record, unless the ivar is indexed. Indexed ivars always have headers, no matter what, since the indexing code relies on it. 2 bytes Offset to the indexed area, rel to the class pointer (which follows). If not indexed, this will be 6. 4 bytes Class pointer (relocatable). 2 bytes Offset from the data start to the class pointer. For simple objects (i.e. not embedded), this is -6. For embedded objects, it will be more negative. Note it will always be negative. (object's data starts here) For indexed objects, the indexed area (after the ivars) is preceded by the indexed descriptor (xdesc) with this format: 2 bytes Width of indexed elements (in bytes) 4 bytes Number of elements minus 1 (i.e. LIMIT-1). The low word of this is used by a CHK instruction if #elements is < 32K. If indexing is attempted on a non-indexed object, the "offset to the indexed area" will be 6, taking us to the beginning of the object's data. The CHK instruction will be done at offset -2 from there, which won't be the #elements, of course, but will be the offset to the class pointer WHICH IS ALWAYS NEGATIVE!! Thus the CHK will always fail! This was a deliberate trick - about the only place in Mops I've resorted to anything like this, you'll be glad to know. ============== Class dictionary entry ================ link/name as for normal words 4 bytes call to BLD - the word which builds an object 4 bytes link to methods chain (relative) 4 bytes link to ivar chain (relative) 2 bytes non-indexed data length 2 bytes width of indexed elements, or zero if not indexed 2 bytes flags 4(n+1) bytes N-way to superclasses (n relocatable addrs terminated by zero) Flag bits: bit 0 "large" - indexed with > 64K elements. bit 1 class is exported from a module ============== ivar dictionary entry ================ 4 bytes hashed name 4 bytes link to prev ivar dic entry (relative addr) 4 bytes class pointer (relocatable) 2 bytes offset of this ivar's data from the base addr of the class 2 bytes number of elements if indexed, or zero if not 2 bytes flags Flag bits: (zero is rightmost - what will we do on PowerPC?) bit 0 1 = ivar gets an object header bit 1 1 = this is a static ivar bit 2 1 = this is a public ivar Note: although indexed objects can have 2^^32 elements, we are assuming that an ivar can't have more than 64K elements. This is because we are limiting the maximum ivar length of a class to 64K bytes, which is a stricter condition. Would anybody want a longer ivar than this?? ============== Method dictionary entry ================ 4 bytes hashed name 4 bytes link to prev method dic entry (relative addr) 2 bytes flags Flag bits: bit 0 1 = private method (note other way round to ivars - we're using 1 for the unusual case) bit 7 1 = there's a callFirst and/or callLast method ========================================================== *) : xx db ; \ useful! 0 value PUB/PRIV \ -1 private, 1 public, 0 default - for ivars and methods false value STATIC? \ true if following ivars are to be static 0 value ^CLASS \ addr of the class we're currently compiling 0 value PIVAR \ hashed name of any public ivar we're accessing 0 value PIVSEL \ hashed selector of any msg being sent to \ to a public ivar 0 value NEWOBJECT \ addr of object being created 0 value #SUP \ number of superclasses for current class 0 value SUPERS_TO_SKIP 0 value INITID \ =============================== \ UTILITY WORDS \ =============================== : PRIVATE -1 -> pub/priv ; \ following methods and ivars will be private : PUBLIC 1 -> pub/priv ; \ following methods and ivars will be public : END_PRIVATE 0 -> pub/priv ; \ back to the default : END_PUBLIC 0 -> pub/priv ; \ ditto : X bld 123 ; \ The 123 blocks optimization! ' x @ forget x constant CLASSMK \ JSR bldVec-base(A3) : EXBASE $ 4E92 w, ; immediate \ JSR (A2) : >OBJ ( cfa -- ^obj ) inline{ 8 +} 8 + ; : OBJ> ( ^obj -- cfa ) inline{ 8 -} 8 - ; \ Note: we don't use >class here, since obj> shouldn't be \ used for embedded objects, and it is used during obj \ building when the ^class isn't there yet. : CHKCLASS \ ( cfa -- cfa ) class? ?EXIT .id space true ?error 80 ; : ?>CLASS ( ^obj -- ^class ) >class dup 0= ?error 81 ; \ If no legal class ptr, probably \ not an obj addr at all! \ the following offsets refer to where a ^class points, i.e. the cfa \ of the class. : MFA inline{ 4 +} 4 + ; \ Methods link : IFA inline{ 8 +} 8 + ; \ ivar link : DFA inline{ 12 +} 12 + ; \ Data len (2 bytes), \ width of indexed elts (2 bytes) : FFA inline{ 16 +} 16 + ; \ Flags : SFA inline{ 18 +} 18 + ; \ Superclass N-way pointer : GETDLEN \ ( ^obj -- n ) Gets length of object's named ivars ?>class dfa w@ ; : (^DLEN) \ ( ^obj -- ^datalen ) This is a low-level word which should \ normally only be used in the Mops system stuff. Note it \ takes ^obj, not ^class, and it doesn't do a module check \ - it assumes the class is in the same segment as the object. ?>class dfa ; : DLEN&XWID \ ( ^class -- dlen xwid ) ?>classInMod dfa dup w@ swap 2+ w@ ?unHoldMod ; : DLEN dlen&xwid drop ; : XWID dlen&xwid nip ; : IVARLEN postpone dlen ; immediate \ an alias for dlen : ?>MAINDIC { ^class -- '^class } \ If ^class is exported from a module, we return the main dic \ equivalent. If it's not exported, we return it unchanged. \ We need this word since for exported classes, we need to use the \ imported address (in the main dictionary) as the class pointer \ in a new object or an ivar dic entry (so that the module will be \ invoked properly when a method is sent to the object. ^class ffa 1+ 1 btest IF ^class >name n>count sfind drop ELSE ^class THEN ; : FINDM { selID ^cl -- offs cfa } \ Finds a method in a class. ^cl ?>classInMod -> ^cl ^cl -> objClass selID ^cl 4 (findm) NIF cr ^cl .id 108 die ( method not found ) THEN ; : IVFINDM \ ( selID ^ivar -- cfa base-offs ) \ Looks for a method in an ivar. \ Note we return the results the other way around to \ objFindM, since this is what we usually want here. 8 + @abs ( addr of ivar's class ) findm swap ; : SEND { ^obj selID \ svMB -- } \ Executes a method given its sel ID. Used in \ late binding. Can also be used if you \ have a dynamically determined method ID. modBase -> svMB selID ^obj objFindM ex-method svMB -> modBase ; : (DEFER) ( ^obj -- ) \ Looks up SelID at IP and runs the method. \ Used in late binding. @(ip) send ; 0 -> quitvec 0 -> abortvec 0 -> objInit \ clear vectors ' pfind -> ufind : ?CLASS \ Error if not compiling a class definition. cstate 0= ?error 115 ; \ IVFIND is called when we've parsed a selector. It determines if the next \ word is an ivar. \ Note: if found, (findm) returns the equivalent of the cfa of \ a method, which for ivars, is the addr of the class pointer. : IVFIND \ ( str-addr -- offs ^ivar T | -- str-addr F ) cstate NIF false EXIT THEN hash ^class 8 (findm) IF 8 - true ELSE here false THEN ; \ TOfind looks for a temp (local) object. : TOfind \ ( str-addr -- cfa T | -- str-addr F ) tmpObjs NIF false EXIT THEN hash tmpObjs 8 (findm) IF 8 - true ELSE here false THEN ; (* LocFind will be called from Ufind, which is the vector that gets first shot at recognizing a word. It looks at all the possibilities involving local names, which are not in the regular dictionary. These possibilities are: named parms/locals, local objects, and if a class is being compiled, ivars of this class. In the latter case, we arrange for the ivar's address to be pushed at run time simply by compiling ^base followed by an add of the ivar's offset - our code generation will produce optimal code for this. We then have to return the xt of some word to keep FIND happy - we don't need to compile anything else, so we use the xt of NULL and return a 1 instead of True - this makes FIND think it's immediate. So NULL is executed immediately, which does precisely nothing. The one exception to this is if the "ivar" turns out to be SELF or SUPER - in this case we need to call the nucleus word SELF which works out the right base address (this is what happened pre-2.5). Here we keep FIND happy by pushing the xt of SELF and True, so that it sees we've found SELF. *) : LocFind \ ( str-addr -- cfa T | -- str-addr F ) Pfind ?dup ?EXIT \ Found a named parm/local TOfind IF \ Found temp obj drop \ Don't need its dic addr postpone locReg postpone literal postpone + ['] null 1 EXIT THEN \ Now we look for an ivar name cstate NIF false EXIT THEN \ search fails if we're not compiling \ a class dup hash ^class 8 (findm) IF \ Found ivar drop nip \ Don't need its dic addr or str addr dup $ FFFE >= \ is it SELF or SUPER ? IF drop ['] self true EXIT THEN postpone ^base postpone literal postpone + ['] null 1 ELSE false THEN ; : ILFA ( infa -- ilfa ) 4+ ; : ^ICLASS ( infa -- ^class | 0 ) 8 + dup @ NIF drop 0 ELSE @abs ?>classInMod THEN ; : IOFFS ( infa -- ioffs ) 12 + w@ ; : I#ELS ( infa -- #els ) 14 + w@ ; : IFFA ( infa -- iffa ) inline{ 16 +} ; : LASTIVAR? \ ( infa -- infa b ) True if nfa is super or self. \ These are distinguished by having an "offset" of \ $ FFFE and $ FFFF respectively. dup @ 0> IF false EXIT THEN \ If there's an Nway for superclasses there, then it can't \ be super or self. dup 12 + w@ $ FFFE >= ; \ Otherwise it's a normal ivar dic entry, so we grab the \ offset field and test it. : ^NEXTIVAR \ ( infa -- infa' ) ilfa displace ; forward INITIVAR \ Performs the classinit: method on the ivar on the stack \ ======================== \ BINDING \ ======================== 0 value OBJ_BASE 0 value OBJ_DISPL 0 value OBJ_LOCAL_DISPL 0 value OBJ_IND false value SELF? : OBJ \ Called from within an inline method. Passes the object's \ base and displacement to Handlers to generate the correct \ address. Optimization will then apply. obj_base obj_displ obj_ind genaddr obj_local_displ postpone literal postpone + ; immediate : IX \ Also called from within an inline method. \ Compiles code to generate the indexed address. ^class dlen&xwid swap self? IF drop -1 ELSE 6 + THEN obj_base obj_displ obj_local_displ obj_ind ^class ffa w@ genxaddr ; immediate local EARLY_BIND { oCfa oBase oDispl oLDispl oind slf? -- } : INL_BIND \ ( -- b ) \ In-line code to be compiled for this method. \ But note, we don't do it if obj_base is zero, meaning that \ we have put the ^obj in A0 as a temporary. Some inline \ methods could cause a clash on A0. So in this case we \ call the out-of-line code - we return true so that this \ will be done by NORM_BIND. Otherwise we return false. obj_base NIF \ Update cfa to the out-of-line code oCfa 2+ dup c@ + aligned -> oCfa true ELSE ^class cstate self? \ Save over upcoming evaluate slf? NIF objClass -> ^class THEN \ Set ^class and cstate true -> cstate \ so ivars are accessible slf? -> self? oCfa (compinl) -> self? -> cstate -> ^class \ Restore false THEN ; : NORM_BIND oCfa postpone obj EB ; :loc EARLY_BIND \ { oCfa oBase oDispl oLDispl oind slf? -- } obj_base obj_displ obj_local_displ obj_ind \ Save oBase -> obj_base oDispl -> obj_displ OLdispl -> obj_local_displ oind -> obj_ind oCfa w@ inlMk = IF inl_bind ELSE true THEN IF norm_bind THEN -> obj_ind -> obj_local_displ -> obj_displ -> obj_base \ Restore ;loc : BIND_TO_OBJ \ ( cfa ^obj -- ) -1 swap 0 0 false early_bind ; : BIND_TO_STK \ ( cfa -- ) stkObj 0 swap false early_bind ; : BIND_TO_IVAR { cfa offs -- } cfa obj_base obj_displ obj_local_displ offs + obj_ind false early_bind ; : BIND_TO_TMPOBJ { cfa offs -- } cfa 4 offs 0 0 false early_bind ; : BIND_TO_SELF { cfa offs -- } cfa obj_base obj_displ offs obj_ind true early_bind ; \ =========================== \ INITIALIZING NEW OBJECTS \ =========================== 0 value ^XDESC \ Used in the setting up of an index descriptor 0 value OFFS \ Used in setting up ivars false value REC? \ Are we compiling a record? false value UNION? \ Are we compiling a union in a record? 0 value UNIONOFFS \ Base offset of the current union : ?HDRS { thisClass ^data infa \ xw flags -- } \ For normal ivars, this word sets up the object headers - namely \ ^class, ^class offset, xoffs and xdesc. But if we're in a record, \ non-indexed ivars don't have an object header. thisClass 0EXIT \ out if self or super infa iffa w@ -> flags flags 1 and 0EXIT \ out if ivar not flagged as needing a header flags 2 and ?EXIT \ out if it's static (doesn't live in the \ object at all) \ OK, we need the headers. Let's set 'em up: thisClass ?>maindic false -> relocChk? ^data 6 - reloc! \ ^class (safe if outside a module true -> relocChk? \ here, since ivars of an obj belonging \ to an exported class can only be \ accessed while the module is running) -6 ^data 2- w! \ ^class offset thisClass xwid -> xw xw NIF \ Not indexed: store dummy xoffs 6 ^data 8 - w! EXIT \ and we're done. THEN thisClass dlen aligned \ Indexed: dup 12 + ^data 8 - w! \ xoffs ^data + -> ^xdesc xw ^xdesc w! \ xdesc infa i#els 1- ^xdesc 2+ ! ; \ #elements forward IVSETUP : NW_IVSETUP { ^nway boffs EOoffs \ initEOoffs svHeldMod thisClass ^slf totalOffs -- } \ Sets up the groups of ivars for each superclass, for a multiply inherited \ object. Each group we call an "embedded object", which sort of describes \ what it is. \ ^nway points to the current superclass pointer in the n-way defining the \ multiple inheritance. boffs is the base offset from newObject, the actual \ top-level (non-ivar) object being created. EOoffs is the extra offset to \ the current embedded object. When an embedded object starts at a non-zero \ EOoffs, we put in front of it a 2-byte offset to the class pointer. Note \ that if the multiply inherited object is an ivar, there may not be a class \ pointer! This doesn't matter, since it's better for multiply inherited \ objects to always have the same format, wherever they are, and any attempt \ to use the class pointer offset to get the (nonexistent) class pointer \ will most probably be caught by our checks. \ With Mops 2.5 we're now sending classinit: separately to each superclass. EOoffs -> initEOoffs BEGIN ^nway @abs ?>classInMod -> thisClass \ may hold a mod boffs EOoffs + initEOoffs - -> totalOffs thisClass ifa displace totalOffs EOoffs ivSetup \ now we send Classinit: thisClass -> objClass initID thisClass 4 (findm) \ ( -- offs cfa T | F ) IF swap newObject + totalOffs + swap ex-method THEN ?unholdMod \ now finished with the mod 1cell ++> ^nway ^nway @ WHILE \ another class coming up - store 2-byte ^class offset first thisClass dlen ++> EOoffs EOoffs aligned -> EOoffs EOoffs negate 8 - \ ^class offset for store EOoffs initEOoffs - \ offset not already included in boffs boffs + newObject + \ final addr for store w! 2 ++> EOoffs REPEAT ; :f IVSETUP { infa boffs EOoffs \ svHeldMod thisClass ^data -- } \ Recursively traverses the tree of nested ivar definitions in a class, \ building the necessary ^class offsets and indexed area headers. \ infa is the nfa of the current ivar, and boffs is the current base offset \ for ivars at this point in the nested ivar structure, relative to newObject, \ the current top-level object being created. \ When this word is called, if thisClass is in a module, the module will \ be held. In some circumstances the caller still needs it. The \ recursive call might require another module to be held, so we have to \ save and restore any module held on entry. heldMod -> svHeldMod \ save heldMod 0 -> heldMod \ clear it so nobody can unhold BEGIN infa @ 0> IF \ we've hit a superclass n-way infa boffs EOoffs NW_ivSetup \ set up superclasses svHeldMod -> heldMod EXIT \ restore heldMod, and out THEN infa lastivar? nip IF \ no more ivars svHeldMod -> heldMod EXIT \ restore heldMod, and out THEN infa iffa w@ 2 and \ static ivars don't live in the object NIF infa ^iclass -> thisClass \ may hold another mod infa ioffs -> offs \ relative offs of this ivar boffs offs + newObject + -> ^data \ First we do a recursive call to set up the \ (nested) ivars of this ivar's class. ?Rdepth \ Check on recursion depth infa ^iclass ifa displace \ infa of last nested ivar ( newNfa ) offs boffs + \ New base offset 0 ivSetup \ Recursive call to set up this ivar ?unHoldMod \ unhold any held mod thisClass ^data infa ?hdrs \ Add headers if nec boffs infa initivar \ Initialize by calling Classinit: THEN infa ^nextivar -> infa \ Step to next ivar and loop. AGAIN ;f forward CLASSINIT \ Will be classinit: newObject - once we can send \ messages \ HASHED-HDR lays down the dic header for an ivar or method. \ The format is: \ \ 4 bytes hash \ 4 bytes link (self-relative addr of prev entry) \ \ This entry has to become the first on the chain, so we pass in the \ addr of the chain header. : HASHED-HDR \ ( chain-hdr hash-val -- ) , \ comma in hash value dup displace \ get abs addr of prev entry displ, \ comma it in as self-relative addr here 8 - swap displ! \ update chain header ; forward DIC-OBJ : IVDEF ( #els ) { iclass \ #els wid siz clOffs flags -- } \ Compiles an ivar dictionary entry. If indexed, must have \ < 64K elements. iclass is the ivar's class. The class of \ which this is an ivar, is pointed to by ^class. pub/priv 1 = 4 and -> flags \ initial flags - set bit 2 if we're public Mword ivFind ?error 117 \ same name as another ivar drop iclass xwid -> wid \ indexed width of ivar class iclass dlen -> siz \ non-indexed size of this ivar \ The initial offset is the current dlen of the class. ^class dfa w@ -> clOffs ^class ifa here hash hashed-hdr \ dic header for ivar iclass ?>mainDic reloc, \ Now we need to comma in the 2-byte offset to the ivar within \ the class. First we need to make some adjustments... \ Do we need to align the offset: siz 1 > \ we do if the ivar size is longer than 1 wid rec? not and \ or if it's indexed, and we're not in a record or IF \ We do need to align the offset. Note that if the \ ivar class is multiply inherited with >1 superclass \ of non-zero length, the ivar size will always be >1. clOffs aligned -> clOffs THEN iclass ffa 1+ 2 btest \ general? dup IF union? ?error 190 THEN \ can't have a general object in a union rec? not or \ or not in a record? IF \ Yes. In this case the ivar will have \ the standard 8-byte object header. So its data 8 ++> clOffs \ will start 8 bytes later than otherwise. 1 or> flags \ and we'll mark this in the ivar flags \ so ?hdrs will do the right thing. THEN clOffs w, wid IF \ Indexed. Stack has #els. We calculate the indexed \ length of this ivar and increment clOffs. \ If we're not in a record, we also need to align the \ non-indexed size of the ivar, since the xdesc must \ be aligned. (If we're in a record, there won't be an \ xdesc.) -> #els rec? NIF siz aligned -> siz THEN #els w, \ Add #els to ivar dic entry #els wid * \ Get indexed length rec? NIF 6 + THEN \ Add 6 for xdesc length ++> clOffs \ Add to clOffs ELSE \ Not indexed. 0 w, THEN static? IF 2 or> flags ELSE siz ++> clOffs \ Bump clOffs by non-indexed size of ivar THEN flags w, (* Now we'll update the class dLen field by whatever we're allocating for this ivar - it will then be the offset to the next ivar. clOffs has the offset so far. In the normal case, this is what goes in dLen. If we're in a union, we MAX it with whatever's already in dLen. This will leave dLen with the longest union element we've reached so far, which will be the final value in case we hit the end of the union. And if this ivar is static, it will live right where we are in the dic, and not in objects of the class, so in this case we leave dLen alone. *) union? IF unionOffs clOffs max -> unionOffs ELSE static? NIF clOffs ^class dfa w! THEN THEN (* Now we'll check if this ivar is to be static - if so, we'll instantiate it right here. *) static? 0EXIT wid IF #els THEN iclass dic-obj ; \ ================================= \ OBJECT BUILDING \ ================================= : CL>LEN ( #els ) { theClass \ wid len -- ( #els ) len2 } \ Gets data length of object given #els and class. theClass dlen&xwid -> wid -> len wid IF ( #els ) dup 32766 > IF theClass ffa 1+ 0 btest 0= ?error 185 then dup wid * 6 + len + ELSE len THEN ; : MAKE_OBJ ( #els ) { theClass ^obj \ svHeldMod wid len #els -- } 0 -> #els theClass ?>classinMod -> theClass heldMod -> svHeldMod 0 -> heldMod \ So dlen&xwid doesn't unhold theClass dlen&xwid -> wid -> len \ Now if there's an indexed width, we set up xdesc, the indexed descriptor wid IF -> #els len aligned -> len ^obj len + -> ^xdesc \ It's after the ivars, and aligned wid ^xdesc w! #els 1- ^xdesc 2+ ! len 12 + ELSE 6 THEN \ Now for the object header. ^obj obj> w! -6 ^obj 2- w! theClass ?>mainDic ^obj 6 - false -> relocChk? reloc! \ obj addr could be in the heap! true -> relocChk? ^obj -> newObject theClass ifa displace 0 0 ivSetup svHeldMod -> heldMod ?unholdMod \ Lastly we send classinit: to the object. Note ivSetup has already \ sent classinit: to each superclass. classinit ; :f DIC-OBJ ( #els ) { theClass \ ^obj -- } \ Builds an object in the dictionary. here >obj -> ^obj \ Where obj data will start theClass cl>len 8 + aligned \ Required length dup room > ?error 186 \ "Not enough room" reserve \ Allocate space for object theClass ^obj make_obj \ Set up the object align-dp ;f 0 value THECLASS :f BLD \ ( (#els) -- ) Builds an object. r> 4- -> theClass cstate IF theClass ivDef \ Build an ivar ELSE create_obj \ Create object header - returns \ its data address when called theClass dic-obj THEN ;f : ]C true -> cstate ; immediate : C[ false -> cstate ; immediate : HASH, \ Compiles hashed word for name at here @word hash , ; \ ============================ \ :CLASS etc. \ ============================ \ Here we set up some quantities so that we can send messages to SELF \ or SUPER. These are treated syntactically as ivars, so to implement \ them we actually set up dummy ivars SELF and SUPER. \ When we're processing a :CLASS definition, we plug the appropriate \ addresses into these ivars. ^SELF is a word defined to return the \ addr of the dummy ivar SELF, so we can do the plugging. \ In the case of SUPER, there may be several superclasses, so we have \ to go through a class descriptor, since that's the only place we look \ for an n-way (a set of addresses). So we set the "class" of SUPER \ to a dummy class SUPCL, which has no ivars or methods (so the search \ will pass right on by), and plug the superclass pointer of SUPCL to \ point to the current n-way for the superclasses of the class we're \ defining. 0 value (^SELF) : ^SELF ['] (^self) displace ; create SUPCL \ dummy superclass classCode here 2 - w! classMk , 0, \ methods link - no methods 0, \ ivar link - patched at :CLASS time \ META is the super class of Object - top of all inheritance : META reveal [ \ Note, we're still at the cfa drop \ Drop the security marker left by colon classCode here 2 - w! classMk , \ class marker goes here 0, \ methods link - none as yet 0, \ ivar link - set to SUPER below 0, \ data len, flags 0, \ super pointer \ Now we set up the SELF and SUPER pseudo-ivars. We set them up exactly \ as if they'd been declared as regular ivars in META. But note we don't \ set up any fields past the "offset" field, since they're irrelevant. create SUP \ this is so we can tick it at SuperRef below. here \ ready for SELF link below hash, SUPER 0, \ empty link ' supCl reloc, \ ^class is dummy supCl (reloc addr reqd) $ FFFE w, \ "offset" FFFE means SUPER here hash, SELF swap displ, \ link 0, \ ^class (gets patched at :CLASS time) $ FFFF w, \ "offset" FFFF means SELF dup ' (^self) displ! ' meta ifa displ! 0 value THISM 0 value SUPERM false value 1SUPER? : :CLASS immediate ?exec header classCode w, here -> ^class 0 -> pub/priv 0 -> #1st 0 -> #last false -> rec? false -> union? false -> static? 307 ; : MERGE_INFO { ^sup ivlen \ ^wid wid prevWid -- dlen } ^sup dlen&xwid -> wid \ indexed width of this superclass ^sup ffa 1+ c@ 5 and \ Merge "general" and "indexed" flags with ^class ffa 1+ cset \ what we have already wid 0EXIT \ If this superclass not indexed, we're done \ This class is indexed - we need to check if prev classes were indexed \ and make sure the widths are compatible. ^class dfa 2+ -> ^wid \ Addr of wid field in class we're building ^wid w@ -> prevWid \ Get previous width wid 32767 = \ "indexed width" of 32767 really means IF \ obj_array. prevWid \ In this case if we already have a width, IF prevWid -> wid \ we use that, ELSE ivlen -> wid \ Otherwise current ivar len becomes the width. THEN THEN prevWid NIF wid ^wid w! \ If no prev width, set width & we're done ELSE prevWid wid <> ?error 88 \ "Incompatible indexed widths" THEN ; local (SUP) { \ ivlen ^nway ^sup thisLen -- } : NEXT_SUPER ( cfa -- ) chkClass -> ^sup ^sup reloc, \ Add ^class to n-way ^sup ivlen merge_info -> thisLen #sup IF \ If this is a subsequent class, ivlen aligned 2+ -> ivlen \ align and allow for ^class offset THEN thisLen ++> ivlen \ And add ivar length of new class 1 ++> #sup ; : SUPERS_LOOP BEGIN \ Loop over superclasses: ' \ cfa of next item on list }or)? IF drop EXIT THEN ( cfa ) next_super \ handle next superclass 1super? ?EXIT \ Yerk has only one superclass AGAIN ; :loc (SUP) 307 ?pairs \ Make sure we're in the right place classMk , 14 reserve \ Space for class record here -> ^nway \ n-way for superclasses will 0 -> ivlen 0 -> #sup \ start here ^nway dup 14 - displ! \ Point methods link here ^nway dup 10 - displ! \ and ivars link false -> relocChk? supers_loop \ Loop over superclasses 0, \ Terminate n-way ^nway ['] supCl mfa displ! ivlen ^class dfa w! \ Set total ivar length ^class ^self 8 + reloc! \ Store ^class in SELF true -> relocChk? postpone ]c ( postpone [ ) \ In a class definition 308 ;loc : SUPER{ false -> 1super? (sup) ; immediate : SUPER( postpone super{ ; immediate : <SUPER true -> 1super? (sup) ; immediate \ For compatibility with Yerk -- only looks for 1 superclass : (;CL) postpone [ postpone c[ 0 ^self 8 + ! ; : ;CLASS (;cl) 308 ?defn ; immediate 0 value DFRSELID true value SLCTRS? \ Set false to treat selectors as normal words \ for full ANSI compatibility : SEL? \ ( addr -- addr b ) True if word at addr is a selector xxx: slctrs? NIF false EXIT THEN dup count tuck 1- + c@ & : = swap 1 > and ; : GETSELECT \ Gets a selector from the input stream mword sel? not ?error 124 hash 0 -> dfrSelID ; ' null vect GET1ST&LAST ' null vect DoCall1ST ' null vect DoCallLast : M_HEADER { selID -- } \ Builds a method header and entry sequence. \ Note: also called from the assembler. ^class mfa selID hashed-hdr \ Build header pub/priv -1 = 1 and w, \ plus private flag (default is public) here -> thisM \ Remember method cfa Mentry ; \ Compile the entry sequence : :M { \ selID -- } immediate \ Start compiling a method. true -> method? \ Used by Handlers ?class 305 rec? ?error 191 \ unmatched '{' in ivar list 0 -> superM getSelect -> selID 10 -> cstate \ Means we've read :m, no call_1st yet selID ^class 4 (findm) \ is method already defined? IF -> superM warnings? IF cr 0 -> out here count type type# 182 \ "Method redefined" THEN heldMod NIF superM ^class > ?error 183 THEN \ - but if in same class, error drop THEN get1st&last ?unHoldMod selID m_header \ Build method header #1st #last + IF thisM 1- 7 bset THEN 2 $ 40 + -> obj_base \ $ 40 indicates A-reg 0 -> obj_displ \ For any inline method calls :noname \ Start to compile the method doCall1st ; \ Compile any Call1st calls first : ;M immediate (;) #last IF true -> method? doCallLast defnEnd false -> method? THEN 0 -> #1st 0 -> #last 305 ?defn ; \ ============== Local sections for methods ============== \ These function just like regular local sections. The implementation \ is nearly the same. 0 value MLOC_ADDR : MLOCAL \ Starts a local section for methods local? ?error 93 1 -> local? \ We change it to the normal -1 \ as soon as "{" is read. postpone :m postpone [ here -> mloc_addr 10 allot \ Like a forward definition. We \ save the addr to patch and leave \ room for the JMP instrn which will \ be planted by (patch) below. private ; : :MLOC immediate public ?loc getSelect drop 95 here mloc_addr (patch) \ Like :F #PL IF PLentry THEN false -> local? \ We do this here so any EXITs \ tidy everything up properly postpone ] ; : ;MLOC immediate (;) 95 ?pairs \ As local? is now false, everything else 305 ?defn ; \ gets tidied up by (;) \ ================ INDEXED, GENERAL etc. ================= \ These are words which can appear in a class declaration, in the \ position \ :class someClass super{ someSuper } general \ They add attributes to the class. : INDEXED \ ( width -- ) Sets a class and its subclasses to indexed ?class ^class dfa 2+ w! ; : LARGE \ Sets the "large" option on an indexed class, allowing \ the number of elements to be greater than 32K. ?class ^class ffa 1+ 0 bset ; : GENERAL (* Sets the "general" option on a class, which will force an ivar of that class to be a general object with a class pointer (so it can be late-bound to) even if it's within a record. Normally you should just not put such ivars in a record, but using GENERAL gives a bit of extra security, for classes for which you know that they will definitely be late-bound to. (An attempt to late-bind to an ivar without a class pointer will give the "not an object" error at run time, which isn't easy to track down.) Note that indexed classes are always general anyway. Also if there's a message sent to [self] somewhere in one of the methods, we know that the class *must* be general, so in this case we simply set the general attribute. *) ?class ^class ffa 1+ 2 bset ; \ =========================== \ SELECTORS \ =========================== \ First, here are the special-purpose things which can follow a selector. \ These can't appear in isolation. \ We allow ** and [] as synonyms of [ ] to late-bind to whatever is on the \ stack. Note: [] is used in JForth. \ We also allow [self] as a synonym of [ self ] : ** 83 die ; \ "Has no meaning unless preceded by a selector" : [] 83 die ; : [SELF] 83 die ; : SUPER> 83 die ; : IVAR> 83 die ; : CLASS_AS> 83 die ; : ] immediate hide dfrSelID NIF postpone ] EXIT THEN state IF 251 ?pairs postpone (defer) dfrSelID , ELSE dfrSelID send THEN 0 -> dfrSelID ; 100 constant pubIvarTyp \ &&& temp false value need_class? false value implicit_late_bind? \ true for pre-2.7 auto-late-bind \ to locals or values (* REFTOKEN ( -- cfa tokenType | -- various type ) is called when we've parsed a selector - it determines the type of the following word. The order of checking determines the priority of names. Up to 2.6 we checked for locals first, but this was a bad idea since a local could have the same name as an object, and implicit late binding to locals was legal. This wouldn't show up until a crash at run time. So now we check for temp objects, then ivars, then locals IF implcit_late_bind? is true. "various" will be the cfa of whatever came after the selector, or ( offset ^ivar ) for ivars and temp objects (which are treated as ivars of the class Dummy). *) : REFTOKEN \ ( -- cfa tokenType | -- various type ) false -> need_class? Mword \ grab next word TOfind IF tmpObjTyp EXIT THEN \ check for temp object IVfind IF ivarTyp EXIT THEN \ check for ivar implicit_late_bind? IF Pfind IF locTyp EXIT THEN \ check for named parm/locals THEN ( here ) dup thread dup @ + (find) 0= ?error 125 dup ['] ** = IF lbTyp EXIT THEN dup ['] [] = IF lbTyp EXIT THEN dup ['] [ = IF bktTyp EXIT THEN dup ['] [self] = IF lbSelfTyp EXIT THEN dup ['] super> = IF superTyp EXIT THEN dup ['] ivar> = IF pubIvarTyp EXIT THEN dup ['] class_as> = IF true -> need_class? classTyp EXIT THEN dup hdlr CASE objCode OF >obj objTyp ENDOF classCode OF classTyp ENDOF -90 OF classTyp ENDOF \ Exported class objPtrCode OF objPtrTyp ENDOF valCode OF valTyp ENDOF wordCode OF wordTyp ENDOF vectCode OF wordTyp ENDOF \ Note: here we can treat vectors as words. 126 die \ "Not an object name" ENDCASE \ but if we got wordTyp or valTyp, it's only legal if implicit_late_bind? \ is true implicit_late_bind? ?EXIT \ all OK - done dup wordTyp = over valTyp = or IF 126 die THEN ; \ These words handle the binding of a selector to whatever follows it. \ FIX_PIVAR does the housekeeping for accessing a public ivar : FIX_PIVAR { ^class in_class? \ offs ^ivar -- cfa offs } pivar ^class 8 (findm) \ ( offs cfa T | F ) 0= ?error 192 \ "ivar not found" swap -> offs 8 - -> ^ivar ^ivar iffa w@ \ get ivar flags dup 4 and 0= ?error 193 \ ivar not public 2 and \ static flag in_class? IF 0= ?error 197 \ ivar not static ELSE ?error 195 \ wrong syntax for public static ivar THEN pivSel ^ivar ivFindM ( cfa loc-offs ) in_class? IF drop ^ivar 26 + ELSE ++> offs offs THEN ; \ PUBLIC_STATIC_IVAR_REF handles a message bind to a public static ivar \ (done via the msg: ivar> in_class someClass syntax) : PUBLIC_STATIC_IVAR_REF refToken classTyp <> ?error 196 \ class name must follow in_class true fix_pivar bind_to_obj ; \ OBJREF handles a reference to a normal object. : OBJREF { selID ^obj \ offs -- } selID IF selID ^obj objFindM swap ELSE \ it's a public ivar reference in the referenced object ^obj >class false fix_pivar ^obj + THEN bind_to_obj ; \ IVARREF handles a reference to an ivar. : IVARREF { selID offs ^ivar \ stat? -- } heldMod 0 -> heldMod \ Save offs $ FFFE >= -> selfRef? \ If self or super. Allows private \ methods to be found by (findm) selfRef? IF supers_to_skip -> sups2skip \ sups2skip is interrogated by (findm). \ This must only be done if self or \ super is the target. ELSE ^ivar iffa w@ 2 and -> stat? \ static ivar? THEN selID IF selID ^ivar ivFindM 0 -> sups2skip 0 -> supers_to_skip ( cfa loc-offs ) selfRef? IF bind_to_self false -> selfRef? ELSE stat? IF drop ^ivar 26 + bind_to_obj ELSE offs + bind_to_ivar THEN THEN ELSE ^ivar ^iclass false fix_pivar stat? IF ^ivar 26 + + bind_to_obj ELSE offs + bind_to_ivar THEN THEN ?unholdMod -> heldMod ; \ OBJPTRREF handles a reference to an object pointer. : OBJPTRREF { selID OP-cfa \ ^cl -- } OP-cfa (comp) \ Compile a fetch of the OP-cfa, \ giving ^obj at run time OP-cfa 4+ @ 0= ?error 86 \ "ObjPtr hasn't had a class specified" OP-cfa 4+ @abs -> ^cl ^cl hdlr -90 = IF \ Class is exported ^cl 6 + wdisplace \ Addr of module compmod = ?error 84 \ It's the module we're compiling - \ this is a no-no, since the ObjPtr \ reference will use the OLD module! ^cl ?>classInMod -> ^cl THEN selID IF selID ^cl findm swap ELSE ^cl false fix_pivar THEN ( cfa offs ) postpone literal postpone + bind_to_stk ; \ TMPOBJREF handles a reference to a temp object. : TMPOBJREF { selID offs ^tmpObj \ svHeldMod -- } heldMod -> svHeldMod 0 -> heldMod selID IF selID ^tmpObj ivFindM ELSE ^tmpObj 8 + @abs false fix_pivar THEN ( cfa loc-offs ) offs + bind_to_tmpObj svHeldMod -> heldMod ; \ CLASSREF handles a reference to a class - this means use the object \ whose addr is on the stack, but ASSUME it is of the given class \ and early bind, without checking. : CLASSREF { selID ^class -- } need_class? IF ' chkClass -> ^class false -> need_class? THEN selID IF selID ^class findm swap ELSE ^class false fix_pivar THEN postpone literal postpone + bind_to_stk ; \ SuperRef handles the msg: super> someSuper construct. : SUPERREF { selID \ ^nway namedClass ^nway' cnt -- } ?class \ Must be compiling a class ' -> namedClass \ get named class xt ^class sfa -> ^nway ^nway -> ^nway' 0 -> cnt BEGIN ^nway' @ 0= ?error 120 \ "superclass" not found ^nway' @abs namedClass = NWHILE 1cell ++> ^nway' 1 ++> cnt REPEAT cnt -> supers_to_skip selID $ FFFE ['] sup ivarRef \ equivalent to msg: super ; forward COMPREF \ PubIvarRef handles the msg: ivar> someIvar IN someObj construct, to \ send a message directly to a public ivar in an object. : PUBIVARREF { selID \ addr len ^class ^ivar -- } selID -> pivSel mword hash -> pivar mword count -> len -> addr addr len " IN" s= IF 0 \ dummy "selID" for compRef (not a legal selector) compRef \ handle whatever object comes after IN. The \ zero selector signals that a public ivar in the \ indicated object is to be accessed. ELSE addr len " IN_CLASS" s= IF public_static_ivar_ref ELSE true ?error 194 \ "wrong syntax for public ivar" THEN THEN ; \ LBselfRef handles messages to [self] - i.e. late bound to Self. : LBSELFREF postpone self postpone (defer) , \ Any class with a late-bound message to self MUST be general. So if \ we're compling a class (we don't have to be), we'll force it to \ general! cstate IF general THEN ; : COMPDFR \ (selID cfa -- ) (comp) postpone (defer) , ; \ Now here are the main words which compile the selector bindings. \ CompRef operates at compile time - it compiles a selector bind. :f COMPREF \ ( selID -- ) refToken \ ( selID addr type ) - addr is ^obj for objects, otherwise \ the cfa of whatever came after the selector. CASE objTyp OF objRef ENDOF ivarTyp OF ivarRef ENDOF objPtrTyp OF objPtrRef ENDOF tmpObjTyp OF tmpObjRef ENDOF classTyp OF classRef ENDOF \ These next 3 can only come up if implicit_late_bind? is true: valTyp OF compdfr ENDOF locTyp OF compdfr ENDOF wordTyp OF compdfr ENDOF lbTyp OF drop postpone (defer) , ENDOF lbSelfTyp OF drop LBselfRef ENDOF bktTyp OF drop -> dfrSelID 251 ENDOF superTyp OF drop superRef ENDOF pubIvarTyp OF drop pubIvarRef ENDOF 82 die \ "Selector can't be used on that" ENDCASE ;f (* RunRef is the execution mode equivalent - it executes a selector bind. We do this simply by compiling it in a buffer then executing it there. This replaces the earlier scheme where we had to separately handle each case as for compRef - this was a Neon carryover. While we're compiling in the buffer, we save the DP on the return stack, then restore it before executing what we compiled (since it might do some compiling itself). This isn't long, but it's a bit tricky: *) variable runRefBuf 56 reserve \ allows 4 nested binds - worst case \ 14 bytes each 0 value bufPtr 0 value hiDP : RUNREF { selID \ svDP svBufPtr svState -- } DP -> svDP \ save DP DP hiDP umax -> hiDP \ so we can reset DP to right place on an error bufPtr NIF runRefBuf ELSE bufPtr THEN dup -> DP -> svBufPtr \ now we'll compile in runRefBuf state -> svState \ save state postpone ] \ need compile state so this compilation works properly selID compRef \ compile the binding postpone (exit) \ and an exit, so we return to interpretation svState -> state \ restore state 0 -> hiDP \ don't need it any more and could cause problems ?unholdMod DP -> bufPtr \ new bufPtr value svDP -> DP \ restore DP since the code might compile something patches_done \ we're about to execute what we just compiled svBufPtr execute \ execute at old bufPtr location svBufPtr -> bufPtr \ then restore old bufPtr ; \ ======== Selector support ========= \ MESSAGE is the handling word invoked by using a selector. : MESSAGE immediate state IF \ Compile state compRef \ Compile the message send ?unHoldMod ELSE runRef \ Run state - execute object/vector reference. \ ?unHoldMod is called by ex-method at the \ end, so we don't need to call it here. THEN ; \ 1stFind lumps together all the special cases we have to look for after \ we've parsed an input word, but before we can do a regular dictionary \ lookup. At present these are selectors, named parms/locals, ivars \ and local objects. If we invent more later, they can easily be added. \ The vector Ufind is then set to this word so it is called before the \ regular dictionary search. If we succeed here, we return the selector \ ID or zero, the cfa of the handling word, and 1 or -1 (this will cause \ FIND to exit without doing anything more). If we fail, we return the \ original string address and false. : 1stFIND \ ( str-addr -- selID message-cfa T | -- str-addr F ) sel? \ is it a selector? IF hash \ yes - leave selID ['] message 1 \ and cfa of message, and 1 (it's immediate) ELSE LocFind \ no - look for the various kinds of local name THEN ; ' 1stFind -> Ufind : OBJLEN \ ( -- objlen ) Computes total data length of current object. ^base (^dlen) dup w@ swap 2+ w@ ?dup IF idxBase 4- @ 1+ * + 4+ THEN ; :f CLASSINIT newObject classinit: [] ;f getSelect classinit: -> initID :f INITIVAR { boffs infa -- } infa ^iclass 0EXIT \ Don't init self or super initID infa ivFindM drop infa ioffs boffs + newObject + \ ( cfa ^data ) swap ex-method ;f \ execute ClassInit: forward DUMP \ SET_CLASS is a utility word used to patch nucleus objects when their classes \ are defined in higher-level files. Actually it could be used to change the \ class of any object, if anyone is silly enough to want to do that. \ Usage: fFcb ['] file set_class : SET_CLASS { ^obj theClass -- } theClass chkClass ^obj 6 - reloc! \ Patch ^class 6 ^obj 8 - w! \ Not indexed (yet) -6 ^obj 2- w! ; \ ^class offset : CHKSAME \ ( ^obj -- ^obj ) \ A check that two objects are of exactly the \ same class. dup >classCfa ^base >classCfa <> ?error 87 ; \ ========= Object pointers ========== \ Object pointers are low-level objects (like VALUEs) which point to a \ normal (high-level) object, and which allow early-bound messages to be \ sent to the object by syntactically sending them to the object pointer. \ The normal syntax is \ ObjPtr ZZZ class_is someClass \ Thereafter, any messages sent to zzz are early-bound to the object that \ zzz points to at the time the message executes. \ If you need to declare the object pointer before the class exists, use \ SET_TO_CLASS once the class is defined, thus: \ \ :class SOMECLASS super{ object } \ \ ' someOP set_to_class someClass \ \ etc. : (ToOP) { ^obj OPcfa \ OPcl -- } ^obj nilP = \ If we're storing nil, anything goes NIF OPcfa 4+ @abs -> OPcl ^obj 6 - @abs OPcl <> IF \ Mismatch. We give some useful(?) info. cr ^obj obj> .id ." -> " OPcfa .id 87 die THEN THEN ^obj OPcfa ! ; :f ToObjPtr state IF lit-addr postpone (toOP) ELSE (toOP) THEN ;f : CLASS_IS \ ( --< class > ) ?exec ' chkClass here 4- reloc! ; : SET_TO_CLASS { ^objPtr \ ^cl --< class > } ' -> ^cl ^objPtr hdlr -62 <> ?error 85 \ "That isn't an ObjPtr" \ Now if "class" is an imported word, we change the handler code \ to "imported class". This is normally done when the module \ is compiled, but it may not be yet, since we probably \ want to refer to the ObjPtr in the module. ^cl hdlr -92 = IF -90 ^cl 2- w! ELSE ^cl chkClass drop THEN ^cl ^objPtr 4+ reloc! ; \ If you are late-binding in a loop, it can be much faster if you do the bind \ just once, then reuse the resulting cfa each time in the loop. This way \ you only have to perform the method search once. To bind initially and get \ the cfa, use \ BIND_WITH ( ^obj --<selector> ^obj-modified cfa ) \ Usage: (saveCfa and ^obj-mod are values or locals) \ (get object's address) bind_with someSelector: -> saveCfa -> ^obj-mod \ (in the loop) ^obj-mod saveCfa ex-method \ The use of the modified object address is a bit obscure, and is related to \ multiple inheritance. The method you actually end up binding to may be in \ one of the superclasses, and the ivars for that superclass may not start at \ the beginning of the object. The modified object address is the start of \ the ivars for the superclass, which is the address the method needs. \ Note also that the method may turn out to be in a module, so when you have \ finished you should put ?unHoldMod to free up the module. : (BWITH) \ ( ^obj selID -- ^obj-modified cfa ) over ?>class findm >r + r> ; : BIND_WITH \ ( ^obj --<selector> ^obj-modified cfa ) getSelect postpone literal postpone (bwith) ; immediate \ =================================== :class OBJECT super{ meta } :m CLASS: ^base ?>class ?>classinMod ;m :m .ID: ^base obj> .id ;m :m .CLASS: ^base >classCfa .id ;m :m ADDR: inline{ obj} ^base ;m :m ABS: ^base ;m \ Included for Neon/Yerk compatibility :m LENGTH: \ ( -- len ) Gets total length of object. objlen ;m (* Here are two methods which operate between this object and another of the same class. Note we don't check that the passed-in object is actually of the same class, since it could be a subclass but still be safe to use here. *) :m COPYTO: \ ( ^obj -- ) Copies the ivar part of the passed-in object \ to self. ^base dup (^dlen) w@ aligned_move ;m :m =?: \ ( ^obj -- b ) Returns true if the ivar part of the passed-in \ object is identical to self. ^base dup (^dlen) w@ (s=) ;m (* The following methods need to be defined for all objects. We give them their default definitions here. *) :m CLASSINIT: ;m \ Our standard constructor method. Called automatically \ whenever an object is created. :m DEEP_CLASSINIT: \ Also does classinit: on all nested ivars. Use for \ totally (re-)initializing an object. ^base -> newObject class: self ifa displace 0 0 ivSetup ?unholdMod ;m (* RELEASE: is our standard destructor method. Any objects that allocate heap storage will redefine this appropriately. Our convention is that an object will release ALL its storage when it gets a release: message. Other methods can be provided to partly release storage, as needed. *) :m RELEASE: inline{ } ;m :m DUMP: .id: self ." class: " .class: self ^base objlen dump ;m :m PRINT: \ Used for a formatted display, if appropriate. \ Default is just a dump. dump: self ;m ;class \ Bytes is used as the allocation primitive for basic classes : BYTES { numBytes \ svRec? -- } ?class rec? -> svRec? true -> rec? \ Don't want an object header here ['] object ivDef numBytes ^class dfa w+! svRec? -> rec? ; (* =================== Local objects ====================== Syntax: : aWord { loc1 loc2 -- } \ Locals are optional, of course temp { var v1 int i1 string s } Or you can use temp{ ... } if you prefer. As the syntax is quite similar to a list of ivars of a class, we actually implement the temp objects as though they're the ivars of a dummy class (which we uncreatively call Dummy). This is just a convenience during the compilation of a defn with temp objects. It allows us to define them and keep them visible during the compilation of the definition, while mainly using existing code for ivar access. We don't need these ivar dic entries once the defn is finished, so we actually put them high in the dictionary out of the way of the defn we're compiling. At the end of the defn, we reinitialize Dummy's ivar link ready for next time. *) getSelect release: constant releaseID :class DUMMY super{ object } ;class ' dummy ifa @ constant dummyIfa : RESETTEMPS dummyIfa ['] dummy ifa ! 0 ['] dummy dfa ! \ clear dlen and xwid ; \ Note we don't have to worry about the mfa since Dummy never gets \ its own methods. (* InitTemps is called when we're compiling the prologue for a definition with temp objects. It compiles a call to make_obj for each object, so that they're properly initialized. Note we can't just call make_obj once using class Dummy, since its ivar list is wiped out after each defn with temp objects, so at run time it won't have any! But we don't need Dummy at run time anyway - we only need the "ivars" which are the temp objects themselves. *) : 1TEMP ( ^iclass ioffs -- ) locReg + make_obj ; :f INITTEMPS { \ infa -- } ['] dummy ifa displace -> infa BEGIN infa @ 0< WHILE infa ^iclass lit-addr infa ioffs postpone literal postpone 1temp infa ^nextivar -> infa REPEAT ;f (* ReleaseTemps is called back from Handlers when it's compiling an exit. It compiles a release: xxx for all temp objects. Because of the way we've defined release: in class Object, for simple objects no code will actually be generated. Note we mustn't call resetTemps here since this might be an EXIT, not the final semicolon. We leave calling resetTemps till a new temp{ comes up. *) : RELEASETEMPS { \ infa -- } ['] dummy ifa displace -> infa BEGIN infa @ 0< WHILE infa ^iclass 0EXIT \ shouldn't happen, actually releaseID infa ivFindM drop infa ioffs bind_to_tmpObj \ compile release: infa ^nextivar -> infa REPEAT ; : }TEMP 130 ?pairs ['] } ! \ restore old action for "}" -> ^class -> state -> cstate -> DP \ restore other things tmpObjs dlen 8 + -> frameSize \ work out frame size local? NIF \ compile prologue unless we're in PLentry initTemps \ a local section (then it gets done THEN \ by :LOC) ['] releaseTemps -> relTmps \ for Handlers callback at exit time ; : TEMP{ immediate (* First we have to allocate an internal local variable as a frame pointer. There are 4 situations. There may or may not already be locals, and we may or may not be in a local section. Note we can be in a local section even if there aren't already locals, since the purpose of the local section might be just to establish a section for these temp objects. If there are already locals, we just add another. If we're not in a local section we need to recompile the entry sequence (done by PLentry) since the number of regs to be saved and set up is different. But if we're in a local section, we don't have to recompile since we haven't called PLentry yet, so we just add the extra local. If there aren't any locals already, we just call initLocs which sets them up, before adding the new one. *) resetTemps #PL IF local? NIF PLentry_addr -> DP THEN ELSE initLocs \ No locs before, so set up for them now THEN local? IF -1 -> local? THEN \ If in a local section, setting local? \ to -1 means we've defined the locals \ so can't do it again " x " here place here addToParmList (* next we save DP and move halfway up in the free dic space - we'll put the "ivar dic entries" for the temp objs there - we don't need them after the defn is compiled. *) here room 2/ ++> DP align-dp cstate true -> cstate state ^class ['] } @ \ save old action for "}" ['] }temp -> } \ "}" will now be same as }temp 130 \ for ?pairs ['] dummy dup -> ^class \ local objs will look like ivars of Dummy -> tmpObjs \ this will enable finding them postpone [ \ stop compiling ; : TEMP gobble{ postpone temp{ ; immediate (* ================= Records and unions ==================== Syntax: record <name> \ The name is optional { var v1 int i1 string s } union <name> \ The name is optional { var v1 int i1 string s } Or you can use record{ ... } or union{ ... } if you prefer, if it's unnamed. The similarity of syntax to temp objects is quite deliberate. But any similarity to Your Favorite Language is entirely accidental. Well actually it's not, but I think this syntax is as good as any, and probably more readable for folks coming from C-land. unions can be nested within records and vice versa. *) : SVREC rec? union? unionOffs ; : RSTREC -> unionOffs -> union? -> rec? ; : ?HANDLE_NAME { \ sv_>in sv_^class sv_rec? -- } >in @ -> sv_>in ^class -> sv_^class rec? -> sv_rec? Mword count " {" s= NIF \ we've got a name for the record true -> rec? \ must do this before defining the name "object" sv_>in >in ! ['] object ivDef sv_rec? -> rec? sv_^class -> ^class gobble{ \ "{" must follow THEN ; : }RECORD 131 ?pairs rstRec ['] } 4+ ! \ restore old action for "}" ( false -> rec? ) ; : RECORD{ ?class \ must be compiling a class ['] } 4+ @ \ save old action for "}" ['] }record -> } \ "}" will now be same as }record svRec \ save parameters for any existing record/union 131 \ for ?pairs true -> rec? false -> union? ; : RECORD ?handle_name record{ ; : }UNION 132 ?pairs unionOffs ^class dfa w! rstRec ['] } 4+ ! ; \ restore old action for "}" : UNION{ ?class \ must be compiling a class ['] } 4+ @ \ save old action for "}" ['] }union -> } \ "}" will now be same as }union svRec \ save record/union parameters 132 \ for ?pairs true -> rec? true -> union? ^class dfa w@ -> unionOffs ; : UNION ?handle_name union{ ; (* ================= Static ivars ==================== Syntax: static { var v1 int i1 string s } Or you can use static{ ... } if you prefer. These are like static class variables in C++ - they belong to the class, not the object, and thus are shared by all objects of the class. We allocate each ivar in the dictionary right after its ivar header. *) : }STATIC 133 ?pairs ['] } 4+ ! \ restore old action for "}" false -> static? ; : STATIC{ ?class \ must be compiling a class ['] } 4+ @ \ save old action for "}" ['] }static -> } \ "}" will now be same as }static 133 \ for ?pairs true -> static? ; : STATIC gobble{ static{ ; \ ========================================== \ CL1 is our first cleanup word - called on an abort. Resets things \ to normal. Later cleanup words do their special stuff, then call CL1. : CL1 (;cl) clrComp ['] (}) -> } resetTemps false -> rec? false -> union? 0 -> extraFind 0 -> bufPtr DP hiDP umax -> DP false -> case_in_names? ; ' cl1 -> abortVec load Struct \ ========================================== (* Normally we don't get here. In order to do various tests on classes, we comment out the <" Struct and run various parts of the torture test stuff following. *) +echo :class VAR super{ object } 4 bytes data :m CLEAR: inline{ 0 obj !} 0 ^base ! ;m :m GET: inline{ obj @} ^base @ ;m :m PUT: inline{ obj !} ^base ! ;m :m GETT: ^base @ ;m :m PUTT: ^base ! ;m :m +: inline{ obj +!} ^base +! ;m :m -: inline{ obj -!} ^base -! ;m :m ->: inline{ @ obj !} chksame get: var put: self ;m :m TEST: db ;m mlocal LOCTEST: { aa \ bb cc -- } :m AAA: aa -> bb ;m :mloc LOCTEST: db aaa: self cc -> bb 1234 drop ;mloc :m PRINT: ^base @ . ;m :m CLASSINIT: $ 123 put: self ;m ;class :class BYTE super( object ) 1 bytes data :m CLEAR: inline{ 0 obj c!} 0 ^base c! ;m :m GET: inline{ obj c@x} ^base c@x ;m :m UGET: inline{ obj c@} ^base c@ ;m :m PUT: inline{ obj c!} ^base c! ;m :m ->: inline{ c@ obj c!} chksame c@ put: self ;m :m PRINT: ^base c@ . ;m :m CLASSINIT: 9 put: self ;m ;class key! :class BOOL super( byte ) :m GET: inline{ obj c@x} ^base c@x ;m :m PUT: inline{ 0<> obj c!} 0<> ^base c! ;m :m SET: inline{ true obj c!} true ^base c! ;m :m PRINT: get: self IF ." true" ELSE ." false" THEN ;m :m CLASSINIT: clear: self ;m ;class :class BARRAY super{ object } 1 indexed :m AT: \ ( index -- n ) inline{ ix c@} ^elem1 c@ ;m :m TO: \ ( n index -- ) inline{ ix c!} ^elem1 c! ;m :m ^ELEM: \ ( index -- addr ) inline{ ix} ^elem1 ;m :m FILL: \ ( value -- ) Fills all elements with value. idxbase limit 2* bounds ?DO dup i c! LOOP drop ;m :m WIDTH: 1 ;m \ Faster than the default in Object :m GETELEM: \ ( addr -- n ) Fetches one element at addr c@x ;m ;class \ Testing static ivars :class SIVTEST super{ var } public static { var V1 bool B1 byte B2 10 barray BB } bool BLOC var VLOC :m QQ: db get: v1 get: b1 get: b2 4 at: bb get: vloc ;m ;class sivtest zzz sivtest sss objPtr myop class_is sivtest : QQQ db get: ivar> b2 in_class sivtest get: ivar> v1 in_class sivtest sss get: ivar> bloc in class_as> sivtest ; key! :class HAHA super{ object } sivtest IVsss :m QQ: db get: ivar> vloc IN ivsss ;m ;class haha hh : WWW temp { sivtest mysiv } db get: ivar> vloc IN mysiv mysiv -> myop get: ivar> vloc IN myop ; +echo \ Testing record{ :class VAR+ super{ var } :m QQ: db get: [self] \ should make class general get: [ self ] db ;m ;class var+ VVV key! +echo :class RECTEST super{ object } var vv record RR { var v1 bool b1 3 barray bbb byte dummyToMakeAddrOdd union { byte b2 var v2 record { byte bb1 byte bb2 } } var v3 } :m TEST: db get: v1 put: b1 get: b2 get: v2 get: bb1 get: bb2 get: v3 ;m ;class recTest rrr test: rrr \ Testing temp objects : q db temp { var v1 var v2 }temp v1 v2 get: v1 get: v2 db ; :class INT super( object ) 2 bytes data :m CLEAR: inline{ 0 obj ! } 0 ^base ! ;m :m UGET: inline{ obj w@ } ^base w@ ;m :m GET: inline{ obj w@x } ^base w@x ;m :m IPUT: ^base w! ;m :m DISP: inline{ obj 2+ @ } ;m :m PUT: inline{ obj w! } ^base w! ;m :m MOVE: inline{ obj 4+ w@ obj w! } ;m :m +: inline{ obj w+! } ^base w+! ;m :m ->: inline{ w@ obj w! } db chksame 1234 drop get: int put: self ;m :m ++>: inline{ w@ obj w+! } db chksame uget: int +: self ;m :m .ID: ." haha" ;m :m TEST: 1234 drop .id: super ;m :m CLASSINIT: db $ 456 put: self ;m ;class :class CC super{ byte int var bool } :m TEST: db uget: self \ offs should be 0 +: self \ offs should be 4 set: self ;m \ offs should be A :m TEST1: db set: self get: super> bool \ should get -1 get: super ;m :m classinit: db ;m ;class cc CCC :class STRANGE super{ object } var VV byte BB :m GET: get: vv get: bb ;m :m PUT: put: bb put: vv ;m ;class :class ARRAY super( object ) 4 indexed \ 8 bytes data \ Comment out to check collapsing of embedded objs :m ^ELEM: \ ( index -- addr ) ^elem4 ;m :m QQQ: inline{ ix } ;m :m AT: \ ( index -- n ) inline{ ix @ } ^elem4 @ ;m :m ATT: ^elem @ ;m \ As for AT:, but not inline \ and uses unoptimized ^elem :m TO: \ ( n index -- ) inline{ ix ! } ^elem4 ! ;m :m +TO: \ ( n index -- ) inline{ ix +! } ^elem4 +! ;m :m -TO: \ ( n index -- ) inline{ ix -! } ^elem4 -! ;m :m FILL: \ ( value -- ) Fills all elements with value. idxbase limit 4* bounds DO dup i ! 4 +LOOP drop ;m :m EXEC: \ ( index -- ) execute the cfa, by jumping there. inline{ ix ex} ^elem: self execute ;m :m TEST: exec: self ;m :m ATEST: 1 at: self ;m ;class var VV :class XXX super( object ) var VV1 var VV2 3 array AA :m TEST: inline{ 9 putt: vv2 get: vv2 at: aa} get: vv2 ;m :m TESTT: db 2 at: aa get: vv1 get: vv2 ;m :m ZZ: inline{ get: vv2 get: vv} get: vv2 ;m :m CLASSINIT: 3 0 do $ 777 i to: aa loop ;m ;class :class YYY super{ xxx } ;class :class ZZZ super{ object } xxx X1 yyy Y1 :m TEST: db ;m ;class zzz Z1 :class QQQ super( object ) xxx XXX1 xxx XXX2 :m TEST: zz: xxx1 zz: xxx2 zz: xxx1 ;m ;class objPtr OO class_is xxx xxx xxxx qqq qqqq xxxx -> oo :class BLOGGS super( object ) var VV 4 array AA :m TEST: db 2 + i - at: aa ;m ;class bloggs BB :class MULT super( var int array ) :m MTEST: uget: super 999 1 to: self ;m :m MAT: at: self ;m ;class objPtr OO class_is mult objPtr OOO class_is int :class IVXX super( object ) 10 bytes data2 int i1 int i2 130 bytes qqqq \ Include to check >128 distance \ index addressing of array qwert 9 array qwert :m ITEST: get: i1 uget: i2 66 put: i2 99 3 to: qwert 1234 drop 3 at: qwert addr: i2 ['] ooo ! ;m :m GETQWERT: addr: qwert ;m ;class int ii 3 mult mm ivxx iv mm -> oo itest: iv . . . mtest: mm . 88 iput: mm \ Note: get: mm will bind to the var, but uget: mm \ will bind to the int and give 88. \ A further test - Doug H found this bug: :class POINT super{ object } int Y \ Vertical coordinate int X \ Horizontal coordinate ;class :class RECT super{ object } point TOPL point BOTR ;class :class test1 super{ object } 20 array a :m classinit: 55 0 to: a ;m :m to: to: a ;m :m at: at: a ;m ;class :class test3 super{ rect test1 } :m classinit: [ 1 -> supers_to_skip ] classinit: super ;m ;class test3 t3 : q db getqwert: iv 3 swap at: ** ; \ Should give 99 : qq db 1 at: mm ; \ Should give 999 : qqq db 1 mat: mm ; \ Should give 999 : qqqq db 1 mm at: mult ; \ Should give 999 : z db 1 mm at: ** ; \ Should give 999 : zz db 1 mm at: array ; \ Should fail : y db 1 at: oo ; \ Should give 999 : yy db 1 mat: oo ; \ Should give 999 : yyy db uget: mm ; \ Should optimize & give 88 : yyyy db addr: mm addr: oo ; \ Both numbers shd be same : yyyyy db uget: ooo ; \ Should give 66 : yyyyyy db 0 at: t3 ; \ Should give 55 : ?CHK <> abort" check FAILED!!!" ; q 99 ?chk qq 999 ?chk qqq 999 ?chk qqqq 999 ?chk z 999 ?chk y 999 ?chk yy 999 ?chk yyy 88 ?chk yyyy ?chk yyyyy 66 ?chk yyyyyy 55 ?chk \ torture tests WORKED! INCREDIBLE!! CONGRATULATIONS!!! \ (but remember to check that ZZ gives a "can't use indexed method" error) key! :class MULTX super( mult ) :m ntest: db 444 1 to: super ;m ;class 4 multx MX \ ivar clash test :class CLASH super( object ) 2 array A1 3 array A2 :m TEST: db 77 1 to: a1 66 0 to: a2 1 at: a1 ;m \ Shd give 77 ;class clash CC