gcc/m2/mc-boot/GStrIO.cc

   1 /* do not edit automatically generated by mc from StrIO.  */
   2 /* StrIO.mod provides simple string input output routines.
   3
   4 Copyright (C) 2001-2025 Free Software Foundation, Inc.
   5 Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.
   6
   7 This file is part of GNU Modula-2.
   8
   9 GNU Modula-2 is free software; you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation; either version 3, or (at your option)
  12 any later version.
  13
  14 GNU Modula-2 is distributed in the hope that it will be useful, but
  15 WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 General Public License for more details.
  18
  19 Under Section 7 of GPL version 3, you are granted additional
  20 permissions described in the GCC Runtime Library Exception, version
  21 3.1, as published by the Free Software Foundation.
  22
  23 You should have received a copy of the GNU General Public License and
  24 a copy of the GCC Runtime Library Exception along with this program;
  25 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  26 <http://www.gnu.org/licenses/>.  */
  27
  28 #include "config.h"
  29 #include "system.h"
  30 #include <stdbool.h>
  31 #   if !defined (PROC_D)
  32 #      define PROC_D
  33        typedef void (*PROC_t) (void);
  34        typedef struct { PROC_t proc; } PROC;
  35 #   endif
  36
  37 #   if !defined (FALSE)
  38 #      define FALSE (1==0)
  39 #   endif
  40
  41 #define _StrIO_C
  42
  43 #include "GStrIO.h"
  44 #   include "GASCII.h"
  45 #   include "GStdIO.h"
  46 #   include "Glibc.h"
  47
  48 static bool IsATTY;
  49
  50 /*
  51    WriteLn - writes a carriage return and a newline
  52              character.
  53 */
  54
  55 extern "C" void StrIO_WriteLn (void);
  56
  57 /*
  58    ReadString - reads a sequence of characters into a string.
  59                 Line editing accepts Del, Ctrl H, Ctrl W and
  60                 Ctrl U.
  61 */
  62
  63 extern "C" void StrIO_ReadString (char *a, unsigned int _a_high);
  64
  65 /*
  66    WriteString - writes a string to the default output.
  67 */
  68
  69 extern "C" void StrIO_WriteString (const char *a_, unsigned int _a_high);
  70
  71 /*
  72    Erase - writes a backspace, space and backspace to remove the
  73            last character displayed.
  74 */
  75
  76 static void Erase (void);
  77
  78 /*
  79    Echo - echos the character, ch, onto the output channel if IsATTY
  80           is true.
  81 */
  82
  83 static void Echo (char ch);
  84
  85 /*
  86    AlphaNum- returns true if character, ch, is an alphanumeric character.
  87 */
  88
  89 static bool AlphaNum (char ch);
  90
  91
  92 /*
  93    Erase - writes a backspace, space and backspace to remove the
  94            last character displayed.
  95 */
  96
  97 static void Erase (void)
  98 {
  99   Echo (ASCII_bs);
 100   Echo (' ');
 101   Echo (ASCII_bs);
 102 }
 103
 104
 105 /*
 106    Echo - echos the character, ch, onto the output channel if IsATTY
 107           is true.
 108 */
 109
 110 static void Echo (char ch)
 111 {
 112   if (IsATTY)
 113     {
 114       StdIO_Write (ch);
 115     }
 116 }
 117
 118
 119 /*
 120    AlphaNum- returns true if character, ch, is an alphanumeric character.
 121 */
 122
 123 static bool AlphaNum (char ch)
 124 {
 125   return (((ch >= 'a') && (ch <= 'z')) || ((ch >= 'A') && (ch <= 'Z'))) || ((ch >= '0') && (ch <= '9'));
 126   /* static analysis guarentees a RETURN statement will be used before here.  */
 127   __builtin_unreachable ();
 128 }
 129
 130
 131 /*
 132    WriteLn - writes a carriage return and a newline
 133              character.
 134 */
 135
 136 extern "C" void StrIO_WriteLn (void)
 137 {
 138   Echo (ASCII_cr);
 139   StdIO_Write (ASCII_lf);
 140 }
 141
 142
 143 /*
 144    ReadString - reads a sequence of characters into a string.
 145                 Line editing accepts Del, Ctrl H, Ctrl W and
 146                 Ctrl U.
 147 */
 148
 149 extern "C" void StrIO_ReadString (char *a, unsigned int _a_high)
 150 {
 151   unsigned int n;
 152   unsigned int high;
 153   char ch;
 154
 155   high = _a_high;
 156   n = 0;
 157   do {
 158     StdIO_Read (&ch);
 159     if ((ch == ASCII_del) || (ch == ASCII_bs))
 160       {
 161         if (n == 0)
 162           {
 163             StdIO_Write (ASCII_bel);
 164           }
 165         else
 166           {
 167             Erase ();
 168             n -= 1;
 169           }
 170       }
 171     else if (ch == ASCII_nak)
 172       {
 173         /* avoid dangling else.  */
 174         while (n > 0)
 175           {
 176             Erase ();
 177             n -= 1;
 178           }
 179       }
 180     else if (ch == ASCII_etb)
 181       {
 182         /* avoid dangling else.  */
 183         if (n == 0)
 184           {
 185             Echo (ASCII_bel);
 186           }
 187         else if (AlphaNum (a[n-1]))
 188           {
 189             /* avoid dangling else.  */
 190             do {
 191               Erase ();
 192               n -= 1;
 193             } while (! ((n == 0) || (! (AlphaNum (a[n-1])))));
 194           }
 195         else
 196           {
 197             /* avoid dangling else.  */
 198             Erase ();
 199             n -= 1;
 200           }
 201       }
 202     else if (n <= high)
 203       {
 204         /* avoid dangling else.  */
 205         if ((ch == ASCII_cr) || (ch == ASCII_lf))
 206           {
 207             const_cast<char *>(a)[n] = ASCII_nul;
 208             n += 1;
 209           }
 210         else if (ch == ASCII_ff)
 211           {
 212             /* avoid dangling else.  */
 213             const_cast<char *>(a)[0] = ch;
 214             if (high > 0)
 215               {
 216                 const_cast<char *>(a)[1] = ASCII_nul;
 217               }
 218             ch = ASCII_cr;
 219           }
 220         else if (ch >= ' ')
 221           {
 222             /* avoid dangling else.  */
 223             Echo (ch);
 224             const_cast<char *>(a)[n] = ch;
 225             n += 1;
 226           }
 227         else if (ch == ASCII_eof)
 228           {
 229             /* avoid dangling else.  */
 230             const_cast<char *>(a)[n] = ch;
 231             n += 1;
 232             ch = ASCII_cr;
 233             if (n <= high)
 234               {
 235                 const_cast<char *>(a)[n] = ASCII_nul;
 236               }
 237           }
 238       }
 239     else if (ch != ASCII_cr)
 240       {
 241         /* avoid dangling else.  */
 242         Echo (ASCII_bel);
 243       }
 244   } while (! ((ch == ASCII_cr) || (ch == ASCII_lf)));
 245 }
 246
 247
 248 /*
 249    WriteString - writes a string to the default output.
 250 */
 251
 252 extern "C" void StrIO_WriteString (const char *a_, unsigned int _a_high)
 253 {
 254   unsigned int n;
 255   unsigned int high;
 256   char a[_a_high+1];
 257
 258   /* make a local copy of each unbounded array.  */
 259   memcpy (a, a_, _a_high+1);
 260
 261   high = _a_high;
 262   n = 0;
 263   while ((n <= high) && (a[n] != ASCII_nul))
 264     {
 265       StdIO_Write (a[n]);
 266       n += 1;
 267     }
 268 }
 269
 270 extern "C" void _M2_StrIO_init (__attribute__((unused)) int argc, __attribute__((unused)) char *argv[], __attribute__((unused)) char *envp[])
 271 {
 272   /* IsATTY := isatty()  */
 273   IsATTY = false;
 274 }
 275
 276 extern "C" void _M2_StrIO_fini (__attribute__((unused)) int argc, __attribute__((unused)) char *argv[], __attribute__((unused)) char *envp[])
 277 {
 278 }