gcc/ada/stringt.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                              S T R I N G T                               --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2003 Free Software Foundation, Inc.          --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, USA.                                                      --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 with System; use System;
  35 with Types;  use Types;
  36
  37 package Stringt is
  38
  39 --  This package contains routines for handling the strings table which is
  40 --  used to store string constants encountered in the source, and also those
  41 --  additional string constants generated by compile time concatenation and
  42 --  other similar processing.
  43
  44 --  A string constant in this table consists of a series of Char_Code values,
  45 --  so that 16-bit character codes can be properly handled if this feature
  46 --  is implemented in the scanner.
  47
  48 --  There is no guarantee that hashing is used in the implementation, although
  49 --  it maybe. This means that the caller cannot count on having the same Id
  50 --  value for two identical strings stored separately and also cannot count on
  51 --  the two Id values being different.
  52
  53    --------------------------------------
  54    -- String Table Access Subprograms --
  55    --------------------------------------
  56
  57    procedure Initialize;
  58    --  Initializes the strings table for a new compilation. Note that
  59    --  Initialize must not be called if Tree_Read is used.
  60
  61    procedure Lock;
  62    --  Lock internal tables before calling back end
  63
  64    procedure Unlock;
  65    --  Unlock internal tables, in case back end needs to modify them
  66
  67    procedure Start_String;
  68    --  Sets up for storing a new string in the table. To store a string, a
  69    --  call is first made to Start_String, then successive calls are
  70    --  made to Store_String_Character to store the characters of the string.
  71    --  Finally, a call to End_String terminates the entry and returns it Id.
  72
  73    procedure Start_String (S : String_Id);
  74    --  Like Start_String with no parameter, except that the contents of the
  75    --  new string is initialized to be a copy of the given string. A test is
  76    --  made to see if S is the last created string, and if so it is shared,
  77    --  rather than copied, this can be particularly helpful for the case of
  78    --  a continued concatenaion of string constants.
  79
  80    procedure Store_String_Char (C : Char_Code);
  81    procedure Store_String_Char (C : Character);
  82    --  Store next character of string, see description above for Start_String
  83
  84    procedure Store_String_Chars (S : String);
  85    procedure Store_String_Chars (S : String_Id);
  86    --  Store character codes of given string in sequence
  87
  88    procedure Store_String_Int (N : Int);
  89    --  Stored decimal representation of integer with possible leading minus
  90
  91    procedure Unstore_String_Char;
  92    --  Undoes effect of previous Store_String_Char call, used in some error
  93    --  situations of unterminated string constants.
  94
  95    function End_String return String_Id;
  96    --  Terminates current string and returns its Id
  97
  98    function String_Length (Id : String_Id) return Nat;
  99    --  Returns length of previously stored string
 100
 101    function Get_String_Char (Id : String_Id; Index : Int) return Char_Code;
 102    pragma Inline (Get_String_Char);
 103    --  Obtains the specified character from a stored string. The lower bound
 104    --  of stored strings is always 1, so the range is 1 .. String_Length (Id).
 105
 106    function String_Equal (L, R : String_Id) return Boolean;
 107    --  Determines if two string literals represent the same string
 108
 109    procedure String_To_Name_Buffer (S : String_Id);
 110    --  Place characters of given string in Name_Buffer, setting Name_Len.
 111    --  Error if any characters are out of Character range. Does not attempt
 112    --  to do any encoding of any characters.
 113
 114    procedure Add_String_To_Name_Buffer (S : String_Id);
 115    --  Append characters of given string to Name_Buffer, updating Name_Len.
 116    --  Error if any characters are out of Character range. Does not attempt
 117    --  to do any encoding of any characters.
 118
 119    function String_Chars_Address return System.Address;
 120    --  Return address of String_Chars table (used by Back_End call to Gigi)
 121
 122    function String_From_Name_Buffer return String_Id;
 123    --  Given a name stored in Namet.Name_Buffer (length in Namet.Name_Len),
 124    --  returns a string of the corresponding value. The value in Name_Buffer
 125    --  is unchanged, and the cases of letters are unchanged.
 126
 127    function Strings_Address return System.Address;
 128    --  Return address of Strings table (used by Back_End call to Gigi)
 129
 130    procedure Tree_Read;
 131    --  Initializes internal tables from current tree file using Tree_Read.
 132    --  Note that Initialize should not be called if Tree_Read is used.
 133    --  Tree_Read includes all necessary initialization.
 134
 135    procedure Tree_Write;
 136    --  Writes out internal tables to current tree file using Tree_Write
 137
 138    procedure Write_Char_Code (Code : Char_Code);
 139    --  Procedure to write a character code value, used for debugging purposes
 140    --  for writing character codes. If the character code is in the range
 141    --  16#20# .. 16#7E#, then the single graphic character corresponding to
 142    --  the code is output. For any other codes in the range 16#00# .. 16#FF#,
 143    --  the code is output as ["hh"] where hh is the two digit hex value for
 144    --  the code. Codes greater than 16#FF# are output as ["hhhh"] where hhhh
 145    --  is the four digit hex representation of the code value (high order
 146    --  byte first). Hex letters are always in lower case.
 147
 148    procedure Write_String_Table_Entry (Id : String_Id);
 149    --  Writes a string value with enclosing quotes to the current file using
 150    --  routines in package Output. Does not write an end of line character.
 151    --  This procedure is used for debug output purposes, and also for output
 152    --  of strings specified by pragma Linker Option to the ali file. 7-bit
 153    --  ASCII graphics (except for double quote) are output literally.
 154    --  The double quote appears as two successive double quotes.
 155    --  All other codes, are output as described for Write_Char_Code. For
 156    --  example, the string created by folding "A" & ASCII.LF & "Hello" will
 157    --  print as "A["0a"]Hello". A No_String value prints simply as "no string"
 158    --  without surrounding quote marks.
 159
 160 private
 161    pragma Inline (End_String);
 162    pragma Inline (String_Length);
 163
 164 end Stringt;