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) 1992-2013, 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 3, 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. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32with System; use System; 33with Types; use Types; 34 35package Stringt is 36 pragma Elaborate_Body; 37 -- This is to make sure Null_String_Id is properly initialized 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 Null_String_Id : String_Id; 54 -- Gets set to a null string with length zero 55 56 -------------------------------------- 57 -- String Table Access Subprograms -- 58 -------------------------------------- 59 60 procedure Initialize; 61 -- Initializes the strings table for a new compilation. Note that 62 -- Initialize must not be called if Tree_Read is used. 63 64 procedure Lock; 65 -- Lock internal tables before calling back end 66 67 procedure Unlock; 68 -- Unlock internal tables, in case back end needs to modify them 69 70 procedure Mark; 71 -- Take a snapshot of the internal tables. Used in conjunction with Release 72 -- when computing temporary string values that need not be preserved. 73 74 procedure Release; 75 -- Restore the internal tables to the situation when Mark was last called. 76 -- If Release is called with no prior call to Mark, the entire string table 77 -- is cleared to its initial (empty) setting. 78 79 procedure Start_String; 80 -- Sets up for storing a new string in the table. To store a string, a 81 -- call is first made to Start_String, then successive calls are 82 -- made to Store_String_Character to store the characters of the string. 83 -- Finally, a call to End_String terminates the entry and returns it Id. 84 85 procedure Start_String (S : String_Id); 86 -- Like Start_String with no parameter, except that the contents of the 87 -- new string is initialized to be a copy of the given string. A test is 88 -- made to see if S is the last created string, and if so it is shared, 89 -- rather than copied, this can be particularly helpful for the case of 90 -- a continued concatenation of string constants. 91 92 procedure Store_String_Char (C : Char_Code); 93 procedure Store_String_Char (C : Character); 94 -- Store next character of string, see description above for Start_String 95 96 procedure Store_String_Chars (S : String); 97 procedure Store_String_Chars (S : String_Id); 98 -- Store character codes of given string in sequence 99 100 procedure Store_String_Int (N : Int); 101 -- Stored decimal representation of integer with possible leading minus 102 103 procedure Unstore_String_Char; 104 -- Undoes effect of previous Store_String_Char call, used in some error 105 -- situations of unterminated string constants. 106 107 function End_String return String_Id; 108 -- Terminates current string and returns its Id 109 110 function String_Length (Id : String_Id) return Nat; 111 -- Returns length of previously stored string 112 113 function Get_String_Char (Id : String_Id; Index : Int) return Char_Code; 114 pragma Inline (Get_String_Char); 115 -- Obtains the specified character from a stored string. The lower bound 116 -- of stored strings is always 1, so the range is 1 .. String_Length (Id). 117 118 function String_Equal (L, R : String_Id) return Boolean; 119 -- Determines if two string literals represent the same string 120 121 procedure String_To_Name_Buffer (S : String_Id); 122 -- Place characters of given string in Name_Buffer, setting Name_Len. 123 -- Error if any characters are out of Character range. Does not attempt 124 -- to do any encoding of any characters. 125 126 procedure Add_String_To_Name_Buffer (S : String_Id); 127 -- Append characters of given string to Name_Buffer, updating Name_Len. 128 -- Error if any characters are out of Character range. Does not attempt 129 -- to do any encoding of any characters. 130 131 function String_Chars_Address return System.Address; 132 -- Return address of String_Chars table (used by Back_End call to Gigi) 133 134 function String_From_Name_Buffer return String_Id; 135 -- Given a name stored in Namet.Name_Buffer (length in Namet.Name_Len), 136 -- returns a string of the corresponding value. The value in Name_Buffer 137 -- is unchanged, and the cases of letters are unchanged. 138 139 function Strings_Address return System.Address; 140 -- Return address of Strings table (used by Back_End call to Gigi) 141 142 procedure Tree_Read; 143 -- Initializes internal tables from current tree file using the relevant 144 -- Table.Tree_Read routines. Note that Initialize should not be called if 145 -- Tree_Read is used. Tree_Read includes all necessary initialization. 146 147 procedure Tree_Write; 148 -- Writes out internal tables to current tree file using the relevant 149 -- Table.Tree_Write routines. 150 151 procedure Write_Char_Code (Code : Char_Code); 152 -- Procedure to write a character code value, used for debugging purposes 153 -- for writing character codes. If the character code is in the range 154 -- 16#20# .. 16#7E#, then the single graphic character corresponding to 155 -- the code is output. For any other codes in the range 16#00# .. 16#FF#, 156 -- the code is output as ["hh"] where hh is the two digit hex value for 157 -- the code. Codes greater than 16#FF# are output as ["hhhh"] where hhhh 158 -- is the four digit hex representation of the code value (high order 159 -- byte first). Hex letters are always in lower case. 160 161 procedure Write_String_Table_Entry (Id : String_Id); 162 -- Writes a string value with enclosing quotes to the current file using 163 -- routines in package Output. Does not write an end of line character. 164 -- This procedure is used for debug output purposes, and also for output 165 -- of strings specified by pragma Linker Option to the ali file. 7-bit 166 -- ASCII graphics (except for double quote) are output literally. 167 -- The double quote appears as two successive double quotes. 168 -- All other codes, are output as described for Write_Char_Code. For 169 -- example, the string created by folding "A" & ASCII.HT & "Hello" will 170 -- print as "A["09"]Hello". A No_String value prints simply as "no string" 171 -- without surrounding quote marks. 172 173private 174 pragma Inline (End_String); 175 pragma Inline (String_Length); 176 177end Stringt; 178