gcc/ada/stringt.h

   1 /****************************************************************************
   2  *                                                                          *
   3  *                         GNAT COMPILER COMPONENTS                         *
   4  *                                                                          *
   5  *                              S T R I N G T                               *
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   7  *                              C Header File                               *
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   9  *            Copyright (C) 1992-2023, Free Software Foundation, Inc.       *
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  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
  26 /* This is the C header that corresponds to the Ada package specification for
  27    Stringt.  It also contains the implementations of inlined functions from the
  28    package body for Stringt.  It was created manually from stringt.ads and
  29    stringt.adb and must be kept synchronized with changes in these files.
  30
  31    Note: only the access functions are provided, since the tree transformer
  32    is not allowed to modify the tree or its auxiliary structures.
  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    A string constant in this table consists of a series of Char_Code values,
  40    so that 16-bit character codes can be properly handled if this feature is
  41    implemented in the scanner.
  42
  43    There is no guarantee that hashing is used in the implementation. This
  44    means that the caller cannot count on having the same Id value for two
  45    identical strings stored separately.
  46
  47    The String_Id values reference entries in the Strings table, which
  48    contains String_Entry records that record the length of each stored string
  49    and its starting location in the String_Chars table.  */
  50
  51 struct String_Entry
  52 {
  53   Int String_Index;
  54   Int Length;
  55 };
  56
  57 /* Pointer to string entry vector. This pointer is passed to the tree
  58    transformer and stored in a global location.  */
  59 extern struct String_Entry *Strings_Ptr;
  60
  61 /* Pointer to name characters table. This pointer is passed to the tree
  62    transformer and stored in a global location for access from here. The
  63    String_Index values are subscripts into this array.  */
  64 extern Char_Code *String_Chars_Ptr;
  65
  66
  67 /* String_Length returns the length of the specified string.  */
  68 INLINE Int String_Length (String_Id);
  69
  70 INLINE Int
  71 String_Length (String_Id Id)
  72 {
  73   return Strings_Ptr[Id - First_String_Id].Length;
  74 }
  75
  76
  77 /* Get_String_Char obtains the specified character from a stored string.  The
  78    lower bound of stored strings is always 1, so the range of values is 1 to
  79    String_Length (Id).  */
  80 INLINE Char_Code Get_String_Char (String_Id, Int);
  81
  82 INLINE Char_Code
  83 Get_String_Char (String_Id Id, Int Index)
  84 {
  85   return
  86     String_Chars_Ptr
  87       [Strings_Ptr[Id - First_String_Id].String_Index + Index - 1];
  88 }