------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- K R U N C H -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2005, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 2, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING. If not, write -- -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- -- Boston, MA 02110-1301, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This procedure implements file name crunching -- First, the name is divided into segments separated by minus signs and -- underscores, then all minus signs and underscores are eliminated. If -- this leaves the name short enough, we are done. -- If not, then the longest segment is located (left-most if there are -- two of equal length), and shortened by dropping its last character. -- This is repeated until the name is short enough. -- As an example, consider the krunch of our-strings-wide_fixed.adb -- to fit the name into 8 characters as required by DOS: -- our-strings-wide_fixed 22 -- our strings wide fixed 19 -- our string wide fixed 18 -- our strin wide fixed 17 -- our stri wide fixed 16 -- our stri wide fixe 15 -- our str wide fixe 14 -- our str wid fixe 13 -- our str wid fix 12 -- ou str wid fix 11 -- ou st wid fix 10 -- ou st wi fix 9 -- ou st wi fi 8 -- Final file name: OUSTWIFX.ADB -- A special rule applies for children of System, Ada, Gnat, and Interfaces. -- In these cases, the following special prefix replacements occur: -- ada- replaced by a- -- gnat- replaced by g- -- interfaces- replaced by i- -- system- replaced by s- -- The rest of the name is krunched in the usual manner described above. -- In addition, these names, as well as the names of the renamed packages -- from the obsolescent features annex, are always krunched to 8 characters -- regardless of the setting of Maxlen. -- As an example of this special rule, consider ada-strings-wide_fixed.adb -- which gets krunched as follows: -- ada-strings-wide_fixed 22 -- a- strings wide fixed 18 -- a- string wide fixed 17 -- a- strin wide fixed 16 -- a- stri wide fixed 15 -- a- stri wide fixe 14 -- a- str wide fixe 13 -- a- str wid fixe 12 -- a- str wid fix 11 -- a- st wid fix 10 -- a- st wi fix 9 -- a- st wi fi 8 -- Final file name: A-STWIFX.ADB -- Since children of units named A, G, I or S might conflict with the names -- of predefined units, the naming rule in that case is that the first hyphen -- is replaced by a tilde sign. -- Note: as described below, this special treatment of predefined library -- unit file names can be inhibited by setting the No_Predef flag. -- Of course there is no guarantee that this algorithm results in uniquely -- crunched names (nor, obviously, is there any algorithm which would do so) -- In fact we run into such a case in the standard library routines with -- children of Wide_Text_IO, so a special rule is applied to deal with this -- clash, namely the prefix ada-wide_text_io- is replaced by a-wt- and then -- the normal crunching rules are applied, so that for example, the unit: -- Ada.Wide_Text_IO.Float_IO -- has the file name -- a-wtflio -- More problems arise with Wide_Wide, so we replace this sequence by -- a z (which is not used much) and also (as in the Wide_Text_IO case), -- we replace the prefix ada.wide_wide_text_io- by a-zt- and then -- the normal crunching rules are applied. -- These are the only irregularity required (so far!) to keep the file names -- unique in the standard predefined libraries. procedure Krunch (Buffer : in out String; Len : in out Natural; Maxlen : Natural; No_Predef : Boolean); pragma Elaborate_Body (Krunch); -- The full file name is stored in Buffer (1 .. Len) on entry. The file -- name is crunched in place and on return Len is updated, so that the -- resulting krunched name is in Buffer (1 .. Len) where Len <= Maxlen. -- Note that Len may be less than or equal to Maxlen on entry, in which -- case it may be possible that Krunch does not modify Buffer. The fourth -- parameter, No_Predef, is a switch which, if set to True, disables the -- normal special treatment of predefined library unit file names. -- -- Note: the string Buffer must have a lower bound of 1, and may not -- contain any blanks (in particular, it must not have leading blanks).