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) 1992-2020, 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. 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 COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26with Namet; use Namet; 27with System; 28with Types; use Types; 29 30package Stringt is 31 pragma Elaborate_Body; 32 -- This is to make sure Null_String_Id is properly initialized 33 34-- This package contains routines for handling the strings table which is 35-- used to store string constants encountered in the source, and also those 36-- additional string constants generated by compile time concatenation and 37-- other similar processing. 38 39-- WARNING: There is a C version of this package. Any changes to this 40-- source file must be properly reflected in the C header file stringt.h 41 42-- A string constant in this table consists of a series of Char_Code values, 43-- so that 16-bit character codes can be properly handled if this feature 44-- is implemented in the scanner. 45 46-- There is no guarantee that hashing is used in the implementation, although 47-- it may be. This means that the caller cannot count on having the same Id 48-- value for two identical strings stored separately and also cannot count on 49-- the two such Id values being different. 50 51 Null_String_Id : String_Id; 52 -- Gets set to a null string with length zero 53 54 -------------------------------------- 55 -- String Table Access Subprograms -- 56 -------------------------------------- 57 58 procedure Initialize; 59 -- Initializes the strings table for a new compilation. 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 Mark; 68 -- Take a snapshot of the internal tables. Used in conjunction with Release 69 -- when computing temporary string values that need not be preserved. 70 71 procedure Release; 72 -- Restore the internal tables to the situation when Mark was last called. 73 -- If Release is called with no prior call to Mark, the entire string table 74 -- is cleared to its initial (empty) setting. 75 76 procedure Start_String; 77 -- Sets up for storing a new string in the table. To store a string, a 78 -- call is first made to Start_String, then successive calls are 79 -- made to Store_String_Character to store the characters of the string. 80 -- Finally, a call to End_String terminates the entry and returns it Id. 81 82 procedure Start_String (S : String_Id); 83 -- Like Start_String with no parameter, except that the contents of the 84 -- new string is initialized to be a copy of the given string. A test is 85 -- made to see if S is the last created string, and if so it is shared, 86 -- rather than copied, this can be particularly helpful for the case of 87 -- a continued concatenation of string constants. 88 89 procedure Store_String_Char (C : Char_Code); 90 procedure Store_String_Char (C : Character); 91 -- Store next character of string, see description above for Start_String 92 93 procedure Store_String_Chars (S : String); 94 procedure Store_String_Chars (S : String_Id); 95 -- Store character codes of given string in sequence 96 97 procedure Store_String_Int (N : Int); 98 -- Stored decimal representation of integer with possible leading minus 99 100 procedure Unstore_String_Char; 101 -- Undoes effect of previous Store_String_Char call, used in some error 102 -- situations of unterminated string constants. 103 104 function End_String return String_Id; 105 -- Terminates current string and returns its Id 106 107 function String_Length (Id : String_Id) return Nat; 108 -- Returns length of previously stored string 109 110 function Get_String_Char (Id : String_Id; Index : Int) return Char_Code; 111 pragma Inline (Get_String_Char); 112 -- Obtains the specified character from a stored string. The lower bound 113 -- of stored strings is always 1, so the range is 1 .. String_Length (Id). 114 115 function String_Equal (L, R : String_Id) return Boolean; 116 -- Determines if two string literals represent the same string 117 118 function String_To_Name (S : String_Id) return Name_Id; 119 -- Convert String_Id to Name_Id 120 121 procedure Append (Buf : in out Bounded_String; S : String_Id); 122 -- Append characters of given string to Buf. Error if any characters are 123 -- out of Character range. Does not attempt to do any encoding of 124 -- characters. 125 126 function To_String (S : String_Id) return String; 127 -- Return S as a String 128 129 procedure String_To_Name_Buffer (S : String_Id); 130 -- Place characters of given string in Name_Buffer, setting Name_Len. 131 -- Error if any characters are out of Character range. Does not attempt 132 -- to do any encoding of any characters. 133 134 function String_Chars_Address return System.Address; 135 -- Return address of String_Chars table (used by Back_End call to Gigi) 136 137 function String_From_Name_Buffer 138 (Buf : Bounded_String := Global_Name_Buffer) return String_Id; 139 -- Given a name stored in Buf, returns a string of the corresponding value. 140 141 function Strings_Address return System.Address; 142 -- Return address of Strings table (used by Back_End call to Gigi) 143 144 procedure Write_Char_Code (Code : Char_Code); 145 -- Procedure to write a character code value, used for debugging purposes 146 -- for writing character codes. If the character code is in the range 147 -- 16#20# .. 16#7E#, then the single graphic character corresponding to 148 -- the code is output. For any other codes in the range 16#00# .. 16#FF#, 149 -- the code is output as ["hh"] where hh is the two digit hex value for 150 -- the code. Codes greater than 16#FF# are output as ["hhhh"] where hhhh 151 -- is the four digit hex representation of the code value (high order 152 -- byte first). Hex letters are always in lower case. 153 154 procedure Write_String_Table_Entry (Id : String_Id); 155 -- Writes a string value with enclosing quotes to the current file using 156 -- routines in package Output. Does not write an end of line character. 157 -- This procedure is used for debug output purposes, and also for output 158 -- of strings specified by pragma Linker Option to the ali file. 7-bit 159 -- ASCII graphics (except for double quote) are output literally. 160 -- The double quote appears as two successive double quotes. 161 -- All other codes, are output as described for Write_Char_Code. For 162 -- example, the string created by folding "A" & ASCII.HT & "Hello" will 163 -- print as "A["09"]Hello". A No_String value prints simply as "no string" 164 -- without surrounding quote marks. 165 166private 167 pragma Inline (End_String); 168 pragma Inline (String_Length); 169 170end Stringt; 171