2 New Features of GNU Pascal.

GPC's new or changed features since the last (non alpha/beta) GPC release are listed here. Items without further description refer to new routines, variables or options.

Features implemented for compatibility to other compilers are marked with, e.g., (B) for BP compatibility.

A few old and obsolete features have been dropped or replaced by cleaner, more flexible or otherwise more useful ones. This might lead to minor problems with old code, but we suppose they're rare and easy to overcome. Backward-incompatible changes are marked with (@).

• new options --[no]-nonlocal-exit (default in --ucsd-pascal and --mac-pascal) (fjf988[fijk].pas, fjf1062*.pas) (U) (M)
• new options --[no]-object-checking (on by default) to check on virtual method calls if VMT pointer is not nil and has matchin Size and NegatedSize entries, new options --[no]-range-and-object-checking which are now equivalent to $R[+-] (fjf1053*.pas) (B)
• new options --[no]-pointer-checking, --[no]-pointer-checking-user-defined; new variable ValidatePointerPtr (fjf1052*.pas, pcerrorc.pas) (these options are off by default!)
• new options --[no]-implicit-result (fjf1022*.pas) (on by default only in --delphi mode!) (D) (@)
• new options --{en,dis}able-predefined-identifier (fjf1037*.pas)
• import within a routine (mod15[c-e].pas)
• the option --no-debug-info was renamed to --disable-debug-info, and --no-default-paths was renamed to --disable-default-paths (@)
• qualified identifiers (chief18.pas, fjf260*.pas, fjf921*.pas, grp1.pas, kurzw1.pas, mod{9,10,13..17}*.pas) (@)
• with -Wnested-comments and without --nested-comments warn about comment openers found within comments (fjf1017*.pas)
• new options --[no-]case-value-checking (fjf1012*.pas)
• optimize arithmetic with a complex and a real operand <20020118143553.B28837@artax.karlin.mff.cuni.cz>
• range checking <Pine.LNX.4.21.0012091605570.8168-100000@rusty.russwhit.com> (chuck5.pas, fjf446.pas, fjf989*.pas, fjf992*.pas, fsc{01..37}*.pas, miklos1[bc].pas, mir{016,021..028,030..047}*.pas, ole[12]*.pas, russ4*.pas)
• Exit with an argument (non-local exits not yet supported) (fjf988*.pas) (U) (M)
• new options --[no-]propagate-units (on by default with --mac-pascal, off in other dialects) (fjf987*.pas) (M); this also covers the item “unit inheritance”
• enable Pointer in --mac-pascal mode (Mac Pascal has a Pointer function which does the same as a type-cast to Pointer; though adding Pointer as a type allows more, it's backward-compatible) (M)
• & and | (shortcut and and or) (fjf981*.pas) (M)
• Leave and Cycle (equivalent to Break and Continue) (avo3.pas) (M)
• optimize WriteLn (... string_constant) and Write (... string_constant, string_constant ...)
• BindingType is now a packed record as EP demands (fjf975a.pas) (E)
• EP structured initializers (fjf964*.pas, fjf967*.pas, fjf968*.pas) (E)
• EP record, array, set values (constdef.pas, fjf966*.pas, fjf971*.pas) (E)
• gp: PC now sets the compiler for both Pascal and C unless CC is set explicitly
• Discard
• Integer, Word, Cardinal are now equivalent to PtrInt, PtrWord, PtrCard, no more (necessarily) to C's int and unsigned int (@)
• new types CInteger, CWord, CCardinal
• new make variable GPC_PAGESIZE to set the page size when building the manual (PDF, PostScript, DVI)
• qualified and import lists are no more allowed after uses (only after import, as EP demands) (@)
• the GMP unit doesn't support gmp-2.x anymore (if you used it, just upgrade to a newer GMP version) (@)
• conflicts between object fields/methods and ancestor type names are detected as required by OOE (fjf945*.pas) (@) (O)
• repeated function headings (in forward declarations and interfaces) are checked stricter: if one has a result variable, so must the other (according to the OOE draft) (@) (O)
• the Pipe unit was renamed to Pipes because of a name conflict (@)
• empty parameter lists can be written as () (chief54*.pas, delphi6*.pas) (D)
• GMP unit: mpf_sin, mpf_cos
• the test suite output is now by default stored in DejaGnu compatible files gpc.log and gpc.sum in the p/test/ directory; other available test targets are pascal.check-short and pascal.check-long (@)
• new options -W[no-]dynamic-arrays (fjf931*.pas)
• new argument to _p_initialize (@)
• UMask
• new option --no-debug-source
• new lexer (no directly user-visible difference, but should allow for better handling of lexer-based problems in the future)
• CompilerAssert (fjf904*.pas)
• options --[no]-assert renamed to --[no]-assertions (necessary to avoid a conflict with GCC) (@)
• new options --[no-]range-checking, also as short compiler directives {$R+}/{$R-} (default is on) (C, E, B, @)
• new options --[no-]methods-always-virtual (fjf903*.pas) (M)
• new options --[no-]pointer-arithmetic, --[no-]cstrings-as-strings, -W[no-]absolute (all of which --[no-]extended-syntax implies)
• Integer2StringBase, Integer2StringBaseExt
• new constants NumericBaseDigits, NumericBaseDigitsUpper
• allow assigning, passing by value and returning objects, with assignments of an object of derived type to one of a base type (chief35[ab].pas, fjf451*.pas, fjf696[ef].pas, fjf884*.pas), BP compatible except for a bug in the BP feature itself (see the comment in p/test/fjf451h.pas) (B)
• new options -W[no-]object-assignment
• warn (except in --borland-pascal) if a virtual method overrides a non-virtual one (chief52*.pas)
• warn when an non-abstract object type has virtual methods, but no constructor (chief51*.pas)
• --maximum-field-alignment does not apply to packed records
• ArcSin, ArcCos
• trimming string relations as functions (EQPad etc.) (fjf873.pas)
• new options -W[no-]interface-file-name
• SeekEOF and SeekEOLn use Input implicitly when no file is given (fjf871.pas) (B)
• tagging feature for with statements (tom6.pas) <200012022215.eB2MFD614424@wsinpa16.win.tue.nl> (Sun Pascal)
• new option --sun-pascal
• field names and array indices in initalizers are recognized (waldek5*.pas) (options -W[no-]field-name-problem removed, @)
• object directives published, public (both equivalent), protected (scope limited to object type and derived object types), private (scope limited to current unit/module) (fjf864*.pas) (options -W[no-]object-directives removed, @)
• the operator precedence and associativity of + and - is now as defined in EP by default (and as in BP with --borland-pascal) <Pine.LNX.4.44.0210251249500.6181-100000@duch.mimuw.edu.pl> (fjf863*.pas) (@)
• Integer (16) etc. changed to Integer attribute (Size = 16) (works for integer and Boolean types) (fjf861.pas) (@)
• types can have attributes (note: no preceding ;) (fjf860*.pas)
• dynamic object methods (fjf859.pas) (B)
• in --borland-pascal mode, Assign unconditionally (re-)initializes its file parameter (fjf858.pas) (B)
• GPC doesn't use gpm files anymore (instead, each module has an implicit modulename-all.gpi interface which is a regular gpi file)
• make the program/module/unit finalizers non-public (static in C sense), omit them if easily possible
• new options -W[no-]parentheses (fjf848*.pas)
• non-interface modules with empty implementation part (pmod1.pas, fjf843.pas)
• maximum-field-alignment and [no-]field-widths work as local compiler directives now (fjf842.pas)
• dropped {$debug-statement} (should not be necessary anymore, now that debug info mostly works)
• new options --[no-]longjmp-all-nonlocal-labels
• object methods can have attributes (fjf826*.pas)
• new attributes iocritical (fjf824*.pas), ignorable (fjf839*.pas) for routines
• dropped computed goto (never worked for nonlocal goto into the main program, implementing it would be quite difficult, probably not worth it) (@)
• new type AnyFile for parameters and pointer targets (fjf821*.pas)
• TimeStamp is now a packed record as EP demands (fjf975b.pas) (E)
• Mac Pascal specific features are supported according to the dialect options (M)
• --interface-only does not require -S or -c anymore (and does not create an object file)
• initialization, finalization (D)
• TimeZone in TimeStamp counts seconds east of UTC now (not west, as before) (datetimedemo.pas) (@)
• export Foo = all (...) (fjf811*.pas)
• new options -W[no-]local-external (implied by -Wall)
• type-casts are BP compatible now, in particular, value type-casts between ordinal and real or complex types don't work anymore (B) (@)
• all non-ISO-7185 keywords can be used as identifiers (with two small exceptions) (fjf440.pas)
• pack-struct does not imply bit-level packing anymore (only explicit packed records and arrays do) (@)
• new options --[no-]ignore-packed (--ignore-packed is the default in BP mode) (fjf796*.pas) (B) (@)
• new option --maximum-field-alignment=N
• new options {$[no-]pack-struct} as a compiler directive
• attribute for routines doesn't imply forward anymore (so you don't have to declare routines twice in a program or implementation part when setting the linker name or some other attribute) (@)
• static, volatile and register for variables and inline for routines are no prefix-directives anymore, but attributes (@)
• combining several dialect options (such as --extended-pascal --borland-pascal) doesn't work anymore (what should this mean, anyway? Combine the features, but also the warnings from both!?!?!?) (@)
• external without name defaults to all-lowercase now (@)
• c, c_language and asmname are deprecated (@)
• external name 'foo' (fjf780.pas), external 'libname' name 'foo' (where libname is ignored) (B)
• Mac Pascal directives definec, macro, undefc, ifc, ifoptc, elsec, elifc, endc, errorc (treated as equivalent to the corresponding existing ones) (M)
• units without implementation part (M)
• new options --vax-pascal, --mac-pascal
• attributes const for variables and name for variables, routines and modules; assembler names and module/unit file names can now be expressions (which must yield string constants) (fjf781*.pas, fjf809*.pas)
• the utilities gpidump and binobj are installed with GPC (B)
• new options -W[no-]identifier-case, -W[no-]identifier-case-local (fjf751*.pas)
• new compiler directive $R foo, equivalent to $L foo.resource (B)
• dropped --[no-]borland-char-constants (now simply coupled to dialect options) (@)
• test suite: support progress messages (TEST_RUN_FLAGS=-p from the Makefile; -p in testgpc); see http://fjf.gnu.de/misc/progress-messages.tar.gz
• = and <> comparisons of structures (arrays, records, ...) except strings and sets are forbidden now (@) (E)
• irrelevant operands and arguments (e.g.: foo in []; bar * []; Im (baz) if baz is of real type) are not necessarily evaluated anymore (which is allowed by the standard); instead, a warning is given if they have side-effects (@)
• accept only one program, unit, module interface or implementation or a module interface and the implementation of the same module in one file; new options --[no-]ignore-garbage-after-dot (fjf735*.pas) (@)
• new options -W[no-]implicit-io (fjf734*.pas)
• new options --enable-keyword, --disable-keyword (fjf733*.pas)
• CBoolean (fjf727.pas)
• dropped the usage of GetMem as a function with one parameter (only the BP compatible usage as a procedure with two parameters remains) (@)
• accessing the variable FileMode now requires using the GPC (or, for BP compatibility, the System) unit (@)
• DupHandle
• dropped the predefined dialect symbols __CLASSIC_PASCAL__, __STANDARD_PASCAL__, __EXTENDED_PASCAL__, __OBJECT_PASCAL__, __UCSD_PASCAL__, __BORLAND_PASCAL__, __DELPHI__, __PASCAL_SC__ and __GNU_PASCAL__ (one can use {$ifopt borland-pascal} etc. instead) (@)
• Succ, Pred, Inc, Dec for real numbers (fjf714*.pas)
• use environment variables GPC_UNIT_PATH, GPC_OBJECT_PATH
• new options -W[no-]float-equal
• new option --ucsd-pascal
• dropped the syntax type foo = procedure (Integer, Real) (i.e., without parameter names) (@)
• CRT: new argument On to CRTSavePreviousScreen
• SetUserID, SetGroupID
• HeapChecking
• new built-in procedure Assert; new options --[no]-assert (also {$C+}, {$C-} for Delphi compatibility) (fjf665*.pas) (D)
• ProcessGroup
• StringUtils: QuoteEnum
• CurrentRoutineName (fjf752.pas)
• TFDD: new unit
• gpc-run: new options -e FILE and -E FILE (redirect/append standard error)

Have fun,

The GNU Pascal Development Team