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Diffstat (limited to 'src/VBox/Devices/EFI/Firmware/BaseTools/Source/C/VfrCompile/Pccts/CHANGES_FROM_131.txt')
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diff --git a/src/VBox/Devices/EFI/Firmware/BaseTools/Source/C/VfrCompile/Pccts/CHANGES_FROM_131.txt b/src/VBox/Devices/EFI/Firmware/BaseTools/Source/C/VfrCompile/Pccts/CHANGES_FROM_131.txt new file mode 100644 index 00000000..0888cbf1 --- /dev/null +++ b/src/VBox/Devices/EFI/Firmware/BaseTools/Source/C/VfrCompile/Pccts/CHANGES_FROM_131.txt @@ -0,0 +1,522 @@ +CHANGES FROM 1.31 + +This file contains the migration of PCCTS from 1.31 in the order that +changes were made. 1.32b7 is the last beta before full 1.32. +Terence Parr, Parr Research Corporation 1995. + + +====================================================================== +1.32b1 +Added Russell Quong to banner, changed banner for output slightly +Fixed it so that you have before / after actions for C++ in class def +Fixed bug in optimizer that made it sometimes forget to set internal + token pointers. Only showed up when a {...} was in the "wrong spot". + +====================================================================== +1.32b2 +Added fixes by Dave Seidel for PC compilers in 32 bit mode (config.h +and set.h). + +====================================================================== +1.32b3 +Fixed hideous bug in code generator for wildcard and for ~token op. + +from Dave Seidel + + Added pcnames.bat + 1. in antlr/main.c: change strcasecmp() to stricmp() + + 2. in dlg/output.c: use DLEXER_C instead on "DLexer.C" + + 3. in h/PBlackBox.h: use <iostream.h> instead of <stream.h> + +====================================================================== +1.32b4 +When the -ft option was used, any path prefix screwed up +the gate on the .h files + +Fixed yet another bug due to the optimizer. + +The exception handling thing was a bit wacko: + +a : ( A B )? A B + | A C + ; + exception ... + +caused an exception if "A C" was the input. In other words, +it found that A C didn't match the (A B)? pred and caused +an exception rather than trying the next alt. All I did +was to change the zzmatch_wsig() macros. + +Fixed some problems in gen.c relating to the name of token +class bit sets in the output. + +Added the tremendously cool generalized predicate. For the +moment, I'll give this bried description. + +a : <<predicate>>? blah + | foo + ; + +This implies that (assuming blah and foo are syntactically +ambiguous) "predicate" indicates the semantic validity of +applying "blah". If "predicate" is false, "foo" is attempted. + +Previously, you had to say: + +a : <<LA(1)==ID ? predicate : 1>>? ID + | ID + ; + +Now, you can simply use "predicate" without the ?: operator +if you turn on ANTLR command line option: "-prc on". This +tells ANTLR to compute that all by itself. It computes n +tokens of lookahead where LT(n) or LATEXT(n) is the farthest +ahead you look. + +If you give a predicate using "-prc on" that is followed +by a construct that can recognize more than one n-sequence, +you will get a warning from ANTLR. For example, + +a : <<isTypeName(LT(1)->getText())>>? (ID|INT) + ; + +This is wrong because the predicate will be applied to INTs +as well as ID's. You should use this syntax to make +the predicate more specific: + +a : (ID)? => <<isTypeName(LT(1)->getText())>>? (ID|INT) + ; + +which says "don't apply the predicate unless ID is the +current lookahead context". + +You cannot currently have anything in the "(context)? =>" +except sequences such as: + +( LPAREN ID | LPAREN SCOPE )? => <<pred>>? + +I haven't tested this THAT much, but it does work for the +C++ grammar. + +====================================================================== +1.32b5 + +Added getLine() to the ANTLRTokenBase and DLGBasedToken classes +left line() for backward compatibility. +---- +Removed SORCERER_TRANSFORM from the ast.h stuff. +------- +Fixed bug in code gen of ANTLR such that nested syn preds work more +efficiently now. The ANTLRTokenBuffer was getting very large +with nested predicates. +------ +Memory leak is now gone from ANTLRTokenBuf; all tokens are deleted. +For backward compatibility reasons, you have to say parser->deleteTokens() +or mytokenbuffer->deleteTokens() but later it will be the default mode. +Say this after the parser is constructed. E.g., + + ParserBlackBox<DLGLexer, MyParser, ANTLRToken> p(stdin); + p.parser()->deleteTokens(); + p.parser()->start_symbol(); + + +============================== +1.32b6 + +Changed so that deleteTokens() will do a delete ((ANTLRTokenBase *)) +on the ptr. This gets the virtual destructor. + +Fixed some weird things in the C++ header files (a few return types). + +Made the AST routines correspond to the book and SORCERER stuff. + +New token stuff: See testcpp/14/test.g + +ANTLR accepts a #pragma gc_tokens which says +[1] Generate label = copy(LT(1)) instead of label=LT(1) for + all labeled token references. +[2] User now has to define ANTLRTokenPtr (as a class or a typedef + to just a pointer) as well as the ANTLRToken class itself. + See the example. + +To delete tokens in token buffer, use deleteTokens() message on parser. + + All tokens that fall off the ANTLRTokenBuffer get deleted + which is what currently happens when deleteTokens() message + has been sent to token buffer. + +We always generate ANTLRTokenPtr instead of 'ANTLRToken *' now. +Then if no pragma set, ANTLR generates a + + class ANTLRToken; + typedef ANTLRToken *ANTLRTokenPtr; + +in each file. + +Made a warning for x:rule_ref <<$x>>; still no warning for $i's, however. +class BB { + +a : x:b y:A <<$x +$y>> + ; + +b : B; + +} +generates +Antlr parser generator Version 1.32b6 1989-1995 +test.g, line 3: error: There are no token ptrs for rule references: '$x' + +=================== +1.32b7: + +[With respect to token object garbage collection (GC), 1.32b7 + backtracks from 1.32b6, but results in better and less intrusive GC. + This is the last beta version before full 1.32.] + +BIGGEST CHANGES: + +o The "#pragma gc_tokens" is no longer used. + +o .C files are now .cpp files (hence, makefiles will have to + be changed; or you can rerun genmk). This is a good move, + but causes some backward incompatibility problems. You can + avoid this by changing CPP_FILE_SUFFIX to ".C" in pccts/h/config.h. + +o The token object class hierarchy has been flattened to include + only three classes: ANTLRAbstractToken, ANTLRCommonToken, and + ANTLRCommonNoRefCountToken. The common token now does garbage + collection via ref counting. + +o "Smart" pointers are now used for garbage collection. That is, + ANTLRTokenPtr is used instead of "ANTLRToken *". + +o The antlr.1 man page has been cleaned up slightly. + +o The SUN C++ compiler now complains less about C++ support code. + +o Grammars which subclass ANTLRCommonToken must wrap all token + pointer references in mytoken(token_ptr). This is the only + serious backward incompatibility. See below. + + +MINOR CHANGES: + +-------------------------------------------------------- +1 deleteTokens() + +The deleteTokens() message to the parser or token buffer has been changed +to one of: + + void noGarbageCollectTokens() { inputTokens->noGarbageCollectTokens(); } + void garbageCollectTokens() { inputTokens->garbageCollectTokens(); } + +The token buffer deletes all non-referenced tokens by default now. + +-------------------------------------------------------- +2 makeToken() + +The makeToken() message returns a new type. The function should look +like: + + virtual ANTLRAbstractToken *makeToken(ANTLRTokenType tt, + ANTLRChar *txt, + int line) + { + ANTLRAbstractToken *t = new ANTLRCommonToken(tt,txt); + t->setLine(line); + return t; + } + +-------------------------------------------------------- +3 TokenType + +Changed TokenType-> ANTLRTokenType (often forces changes in AST defs due +to #[] constructor called to AST(tokentype, string)). + +-------------------------------------------------------- +4 AST() + +You must define AST(ANTLRTokenPtr t) now in your AST class definition. +You might also have to include ATokPtr.h above the definition; e.g., +if AST is defined in a separate file, such as AST.h, it's a good idea +to include ATOKPTR_H (ATokPtr.h). For example, + + #include ATOKPTR_H + class AST : public ASTBase { + protected: + ANTLRTokenPtr token; + public: + AST(ANTLRTokenPtr t) { token = t; } + void preorder_action() { + char *s = token->getText(); + printf(" %s", s); + } + }; + +Note the use of smart pointers rather than "ANTLRToken *". + +-------------------------------------------------------- +5 SUN C++ + +From robertb oakhill.sps.mot.com Bob Bailey. Changed ANTLR C++ output +to avoid an error in Sun C++ 3.0.1. Made "public" return value +structs created to hold multiple return values public. + +-------------------------------------------------------- +6 genmk + +Fixed genmk so that target List.* is not included anymore. It's +called SList.* anyway. + +-------------------------------------------------------- +7 \r vs \n + +Scott Vorthmann <vorth cmu.edu> fixed antlr.g in ANTLR so that \r +is allowed as the return character as well as \n. + +-------------------------------------------------------- +8 Exceptions + +Bug in exceptions attached to labeled token/tokclass references. Didn't gen +code for exceptions. This didn't work: + +a : "help" x:ID + ; + exception[x] + catch MismatchedToken : <<printf("eh?\n");>> + +Now ANTLR generates (which is kinda big, but necessary): + + if ( !_match_wsig(ID) ) { + if ( guessing ) goto fail; + _signal=MismatchedToken; + switch ( _signal ) { + case MismatchedToken : + printf("eh?\n"); + _signal = NoSignal; + break; + default : + goto _handler; + } + } + +which implies that you can recover and continue parsing after a missing/bad +token reference. + +-------------------------------------------------------- +9 genmk + +genmk now correctly uses config file for CPP_FILE_SUFFIX stuff. + +-------------------------------------------------------- +10 general cleanup / PURIFY + +Anthony Green <green vizbiz.com> suggested a bunch of good general +clean up things for the code; he also suggested a few things to +help out the "PURIFY" memory allocation checker. + +-------------------------------------------------------- +11 $-variable references. + +Manuel ORNATO indicated that a $-variable outside of a rule caused +ANTLR to crash. I fixed this. + +12 Tom Moog suggestion + +Fail action of semantic predicate needs "{}" envelope. FIXED. + +13 references to LT(1). + +I have enclosed all assignments such as: + + _t22 = (ANTLRTokenPtr)LT(1); + +in "if ( !guessing )" so that during backtracking the reference count +for token objects is not increased. + + +TOKEN OBJECT GARBAGE COLLECTION + +1 INTRODUCTION + +The class ANTLRCommonToken is now garbaged collected through a "smart" +pointer called ANTLRTokenPtr using reference counting. Any token +object not referenced by your grammar actions is destroyed by the +ANTLRTokenBuffer when it must make room for more token objects. +Referenced tokens are then destroyed in your parser when local +ANTLRTokenPtr objects are deleted. For example, + +a : label:ID ; + +would be converted to something like: + +void yourclass::a(void) +{ + zzRULE; + ANTLRTokenPtr label=NULL; // used to be ANTLRToken *label; + zzmatch(ID); + label = (ANTLRTokenPtr)LT(1); + consume(); + ... +} + +When the "label" object is destroyed (it's just a pointer to your +input token object LT(1)), it decrements the reference count on the +object created for the ID. If the count goes to zero, the object +pointed by label is deleted. + +To correctly manage the garbage collection, you should use +ANTLRTokenPtr instead of "ANTLRToken *". Most ANTLR support code +(visible to the user) has been modified to use the smart pointers. + +*************************************************************** +Remember that any local objects that you create are not deleted when a +lonjmp() is executed. Unfortunately, the syntactic predicates (...)? +use setjmp()/longjmp(). There are some situations when a few tokens +will "leak". +*************************************************************** + +2 DETAILS + +o The default is to perform token object garbage collection. + You may use parser->noGarbageCollectTokens() to turn off + garbage collection. + + +o The type ANTLRTokenPtr is always defined now (automatically). + If you do not wish to use smart pointers, you will have to + redefined ANTLRTokenPtr by subclassing, changing the header + file or changing ANTLR's code generation (easy enough to + do in gen.c). + +o If you don't use ParserBlackBox, the new initialization sequence is: + + ANTLRTokenPtr aToken = new ANTLRToken; + scan.setToken(mytoken(aToken)); + + where mytoken(aToken) gets an ANTLRToken * from the smart pointer. + +o Define C++ preprocessor symbol DBG_REFCOUNTTOKEN to see a bunch of + debugging stuff for reference counting if you suspect something. + + +3 WHY DO I HAVE TO TYPECAST ALL MY TOKEN POINTERS NOW?????? + +If you subclass ANTLRCommonToken and then attempt to refer to one of +your token members via a token pointer in your grammar actions, the +C++ compiler will complain that your token object does not have that +member. For example, if you used to do this + +<< +class ANTLRToken : public ANTLRCommonToken { + int muck; + ... +}; +>> + +class Foo { +a : t:ID << t->muck = ...; >> ; +} + +Now, you must do change the t->muck reference to: + +a : t:ID << mytoken(t)->muck = ...; >> ; + +in order to downcast 't' to be an "ANTLRToken *" not the +"ANTLRAbstractToken *" resulting from ANTLRTokenPtr::operator->(). +The macro is defined as: + +/* + * Since you cannot redefine operator->() to return one of the user's + * token object types, we must down cast. This is a drag. Here's + * a macro that helps. template: "mytoken(a-smart-ptr)->myfield". + */ +#define mytoken(tp) ((ANTLRToken *)(tp.operator->())) + +You have to use macro mytoken(grammar-label) now because smart +pointers are not specific to a parser's token objects. In other +words, the ANTLRTokenPtr class has a pointer to a generic +ANTLRAbstractToken not your ANTLRToken; the ANTLR support code must +use smart pointers too, but be able to work with any kind of +ANTLRToken. Sorry about this, but it's C++'s fault not mine. Some +nebulous future version of the C++ compilers should obviate the need +to downcast smart pointers with runtime type checking (and by allowing +different return type of overridden functions). + +A way to have backward compatible code is to shut off the token object +garbage collection; i.e., use parser->noGarbageCollectTokens() and +change the definition of ANTLRTokenPtr (that's why you get source code +<wink>). + + +PARSER EXCEPTION HANDLING + +I've noticed some weird stuff with the exception handling. I intend +to give this top priority for the "book release" of ANTLR. + +========== +1.32 Full Release + +o Changed Token class hierarchy to be (Thanks to Tom Moog): + + ANTLRAbstractToken + ANTLRRefCountToken + ANTLRCommonToken + ANTLRNoRefCountCommonToken + +o Added virtual panic() to ANTLRAbstractToken. Made ANTLRParser::panic() + virtual also. + +o Cleaned up the dup() stuff in AST hierarchy to use shallowCopy() to + make node copies. John Farr at Medtronic suggested this. I.e., + if you want to use dup() with either ANTLR or SORCERER or -transform + mode with SORCERER, you must defined shallowCopy() as: + + virtual PCCTS_AST *shallowCopy() + { + return new AST; + p->setDown(NULL); + p->setRight(NULL); + return p; + } + + or + + virtual PCCTS_AST *shallowCopy() + { + return new AST(*this); + } + + if you have defined a copy constructor such as + + AST(const AST &t) // shallow copy constructor + { + token = t.token; + iconst = t.iconst; + setDown(NULL); + setRight(NULL); + } + +o Added a warning with -CC and -gk are used together. This is broken, + hence a warning is appropriate. + +o Added warning when #-stuff is used w/o -gt option. + +o Updated MPW installation. + +o "Miller, Philip W." <MILLERPW f1groups.fsd.jhuapl.edu> suggested + that genmk be use RENAME_OBJ_FLAG RENAME_EXE_FLAG instead of + hardcoding "-o" in genmk.c. + +o made all exit() calls use EXIT_SUCCESS or EXIT_FAILURE. + +=========================================================================== +1.33 + +EXIT_FAILURE and EXIT_SUCCESS were not always defined. I had to modify +a bunch of files to use PCCTS_EXIT_XXX, which forces a new version. Sorry +about that. + |