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      1 /* Python format strings.
      2    Copyright (C) 2001-2004, 2006 Free Software Foundation, Inc.
      3    Written by Bruno Haible <haible (at) clisp.cons.org>, 2001.
      4 
      5    This program is free software; you can redistribute it and/or modify
      6    it under the terms of the GNU General Public License as published by
      7    the Free Software Foundation; either version 2, or (at your option)
      8    any later version.
      9 
     10    This program is distributed in the hope that it will be useful,
     11    but WITHOUT ANY WARRANTY; without even the implied warranty of
     12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     13    GNU General Public License for more details.
     14 
     15    You should have received a copy of the GNU General Public License
     16    along with this program; if not, write to the Free Software Foundation,
     17    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
     18 
     19 #ifdef HAVE_CONFIG_H
     20 # include <config.h>
     21 #endif
     22 
     23 #include <stdbool.h>
     24 #include <stdlib.h>
     25 #include <string.h>
     26 
     27 #include "format.h"
     28 #include "c-ctype.h"
     29 #include "xalloc.h"
     30 #include "xvasprintf.h"
     31 #include "format-invalid.h"
     32 #include "gettext.h"
     33 
     34 #define _(str) gettext (str)
     35 
     36 /* Python format strings are described in
     37      Python Library reference
     38      2. Built-in Types, Exceptions and Functions
     39      2.1. Built-in Types
     40      2.1.5. Sequence Types
     41      2.1.5.2. String Formatting Operations
     42    Any string or Unicode string can act as format string via the '%' operator,
     43    implemented in stringobject.c and unicodeobject.c.
     44    A directive
     45    - starts with '%'
     46    - is optionally followed by '(ident)' where ident is any sequence of
     47      characters with balanced left and right parentheses,
     48    - is optionally followed by any of the characters '-' (left justification),
     49      '+' (sign), ' ' (blank), '#' (alt), '0' (zero), each of which acts as a
     50      flag,
     51    - is optionally followed by a width specification: '*' (reads an argument)
     52      or a nonempty digit sequence,
     53    - is optionally followed by '.' and a precision specification: '*' (reads
     54      an argument) or a nonempty digit sequence,
     55    - is optionally followed by a size specifier, one of 'h' 'l' 'L'.
     56    - is finished by a specifier
     57        - '%', that needs no argument,
     58        - 'c', that needs a character argument,
     59        - 's', 'r', that need a string argument,
     60        - 'i', 'd', 'u', 'o', 'x', 'X', that need an integer argument,
     61        - 'e', 'E', 'f', 'g', 'G', that need a floating-point argument.
     62    Use of '(ident)' and use of unnamed argument specifications are exclusive,
     63    because the first requires a mapping as argument, while the second requires
     64    a tuple as argument.
     65  */
     66 
     67 enum format_arg_type
     68 {
     69   FAT_NONE,
     70   FAT_ANY,
     71   FAT_CHARACTER,
     72   FAT_STRING,
     73   FAT_INTEGER,
     74   FAT_FLOAT
     75 };
     76 
     77 struct named_arg
     78 {
     79   char *name;
     80   enum format_arg_type type;
     81 };
     82 
     83 struct unnamed_arg
     84 {
     85   enum format_arg_type type;
     86 };
     87 
     88 struct spec
     89 {
     90   unsigned int directives;
     91   unsigned int named_arg_count;
     92   unsigned int unnamed_arg_count;
     93   unsigned int allocated;
     94   struct named_arg *named;
     95   struct unnamed_arg *unnamed;
     96 };
     97 
     98 /* Locale independent test for a decimal digit.
     99    Argument can be  'char' or 'unsigned char'.  (Whereas the argument of
    100    <ctype.h> isdigit must be an 'unsigned char'.)  */
    101 #undef isdigit
    102 #define isdigit(c) ((unsigned int) ((c) - '0') < 10)
    103 
    104 
    105 static int
    106 named_arg_compare (const void *p1, const void *p2)
    107 {
    108   return strcmp (((const struct named_arg *) p1)->name,
    109 		 ((const struct named_arg *) p2)->name);
    110 }
    111 
    112 #define INVALID_MIXES_NAMED_UNNAMED() \
    113   xstrdup (_("The string refers to arguments both through argument names and through unnamed argument specifications."))
    114 
    115 static void *
    116 format_parse (const char *format, bool translated, char **invalid_reason)
    117 {
    118   struct spec spec;
    119   struct spec *result;
    120 
    121   spec.directives = 0;
    122   spec.named_arg_count = 0;
    123   spec.unnamed_arg_count = 0;
    124   spec.allocated = 0;
    125   spec.named = NULL;
    126   spec.unnamed = NULL;
    127 
    128   for (; *format != '\0';)
    129     if (*format++ == '%')
    130       {
    131 	/* A directive.  */
    132 	char *name = NULL;
    133 	enum format_arg_type type;
    134 
    135 	spec.directives++;
    136 
    137 	if (*format == '(')
    138 	  {
    139 	    unsigned int depth;
    140 	    const char *name_start;
    141 	    const char *name_end;
    142 	    size_t n;
    143 
    144 	    name_start = ++format;
    145 	    depth = 0;
    146 	    for (; *format != '\0'; format++)
    147 	      {
    148 		if (*format == '(')
    149 		  depth++;
    150 		else if (*format == ')')
    151 		  {
    152 		    if (depth == 0)
    153 		      break;
    154 		    else
    155 		      depth--;
    156 		  }
    157 	      }
    158 	    if (*format == '\0')
    159 	      {
    160 		*invalid_reason = INVALID_UNTERMINATED_DIRECTIVE ();
    161 		goto bad_format;
    162 	      }
    163 	    name_end = format++;
    164 
    165 	    n = name_end - name_start;
    166 	    name = (char *) xmalloc (n + 1);
    167 	    memcpy (name, name_start, n);
    168 	    name[n] = '\0';
    169 	  }
    170 
    171 	while (*format == '-' || *format == '+' || *format == ' '
    172 	       || *format == '#' || *format == '0')
    173 	  format++;
    174 
    175 	if (*format == '*')
    176 	  {
    177 	    format++;
    178 
    179 	    /* Named and unnamed specifications are exclusive.  */
    180 	    if (spec.named_arg_count > 0)
    181 	      {
    182 		*invalid_reason = INVALID_MIXES_NAMED_UNNAMED ();
    183 		goto bad_format;
    184 	      }
    185 
    186 	    if (spec.allocated == spec.unnamed_arg_count)
    187 	      {
    188 		spec.allocated = 2 * spec.allocated + 1;
    189 		spec.unnamed = (struct unnamed_arg *) xrealloc (spec.unnamed, spec.allocated * sizeof (struct unnamed_arg));
    190 	      }
    191 	    spec.unnamed[spec.unnamed_arg_count].type = FAT_INTEGER;
    192 	    spec.unnamed_arg_count++;
    193 	  }
    194 	else if (isdigit (*format))
    195 	  {
    196 	    do format++; while (isdigit (*format));
    197 	  }
    198 
    199 	if (*format == '.')
    200 	  {
    201 	    format++;
    202 
    203 	    if (*format == '*')
    204 	      {
    205 		format++;
    206 
    207 		/* Named and unnamed specifications are exclusive.  */
    208 		if (spec.named_arg_count > 0)
    209 		  {
    210 		    *invalid_reason = INVALID_MIXES_NAMED_UNNAMED ();
    211 		    goto bad_format;
    212 		  }
    213 
    214 		if (spec.allocated == spec.unnamed_arg_count)
    215 		  {
    216 		    spec.allocated = 2 * spec.allocated + 1;
    217 		    spec.unnamed = (struct unnamed_arg *) xrealloc (spec.unnamed, spec.allocated * sizeof (struct unnamed_arg));
    218 		  }
    219 		spec.unnamed[spec.unnamed_arg_count].type = FAT_INTEGER;
    220 		spec.unnamed_arg_count++;
    221 	      }
    222 	    else if (isdigit (*format))
    223 	      {
    224 		do format++; while (isdigit (*format));
    225 	      }
    226 	  }
    227 
    228 	if (*format == 'h' || *format == 'l' || *format == 'L')
    229 	  format++;
    230 
    231 	switch (*format)
    232 	  {
    233 	  case '%':
    234 	    type = FAT_ANY;
    235 	    break;
    236 	  case 'c':
    237 	    type = FAT_CHARACTER;
    238 	    break;
    239 	  case 's': case 'r':
    240 	    type = FAT_STRING;
    241 	    break;
    242 	  case 'i': case 'd': case 'u': case 'o': case 'x': case 'X':
    243 	    type = FAT_INTEGER;
    244 	    break;
    245 	  case 'e': case 'E': case 'f': case 'g': case 'G':
    246 	    type = FAT_FLOAT;
    247 	    break;
    248 	  default:
    249 	    *invalid_reason =
    250 	      (*format == '\0'
    251 	       ? INVALID_UNTERMINATED_DIRECTIVE ()
    252 	       : INVALID_CONVERSION_SPECIFIER (spec.directives, *format));
    253 	    goto bad_format;
    254 	  }
    255 
    256 	if (name != NULL)
    257 	  {
    258 	    /* Named argument.  */
    259 
    260 	    /* Named and unnamed specifications are exclusive.  */
    261 	    if (spec.unnamed_arg_count > 0)
    262 	      {
    263 		*invalid_reason = INVALID_MIXES_NAMED_UNNAMED ();
    264 		goto bad_format;
    265 	      }
    266 
    267 	    if (spec.allocated == spec.named_arg_count)
    268 	      {
    269 		spec.allocated = 2 * spec.allocated + 1;
    270 		spec.named = (struct named_arg *) xrealloc (spec.named, spec.allocated * sizeof (struct named_arg));
    271 	      }
    272 	    spec.named[spec.named_arg_count].name = name;
    273 	    spec.named[spec.named_arg_count].type = type;
    274 	    spec.named_arg_count++;
    275 	  }
    276 	else if (*format != '%')
    277 	  {
    278 	    /* Unnamed argument.  */
    279 
    280 	    /* Named and unnamed specifications are exclusive.  */
    281 	    if (spec.named_arg_count > 0)
    282 	      {
    283 		*invalid_reason = INVALID_MIXES_NAMED_UNNAMED ();
    284 		goto bad_format;
    285 	      }
    286 
    287 	    if (spec.allocated == spec.unnamed_arg_count)
    288 	      {
    289 		spec.allocated = 2 * spec.allocated + 1;
    290 		spec.unnamed = (struct unnamed_arg *) xrealloc (spec.unnamed, spec.allocated * sizeof (struct unnamed_arg));
    291 	      }
    292 	    spec.unnamed[spec.unnamed_arg_count].type = type;
    293 	    spec.unnamed_arg_count++;
    294 	  }
    295 
    296 	format++;
    297       }
    298 
    299   /* Sort the named argument array, and eliminate duplicates.  */
    300   if (spec.named_arg_count > 1)
    301     {
    302       unsigned int i, j;
    303       bool err;
    304 
    305       qsort (spec.named, spec.named_arg_count, sizeof (struct named_arg),
    306 	     named_arg_compare);
    307 
    308       /* Remove duplicates: Copy from i to j, keeping 0 <= j <= i.  */
    309       err = false;
    310       for (i = j = 0; i < spec.named_arg_count; i++)
    311 	if (j > 0 && strcmp (spec.named[i].name, spec.named[j-1].name) == 0)
    312 	  {
    313 	    enum format_arg_type type1 = spec.named[i].type;
    314 	    enum format_arg_type type2 = spec.named[j-1].type;
    315 	    enum format_arg_type type_both;
    316 
    317 	    if (type1 == type2 || type2 == FAT_ANY)
    318 	      type_both = type1;
    319 	    else if (type1 == FAT_ANY)
    320 	      type_both = type2;
    321 	    else
    322 	      {
    323 		/* Incompatible types.  */
    324 		type_both = FAT_NONE;
    325 		if (!err)
    326 		  *invalid_reason =
    327 		    xasprintf (_("The string refers to the argument named '%s' in incompatible ways."), spec.named[i].name);
    328 		err = true;
    329 	      }
    330 
    331 	    spec.named[j-1].type = type_both;
    332 	    free (spec.named[i].name);
    333 	  }
    334 	else
    335 	  {
    336 	    if (j < i)
    337 	      {
    338 		spec.named[j].name = spec.named[i].name;
    339 		spec.named[j].type = spec.named[i].type;
    340 	      }
    341 	    j++;
    342 	  }
    343       spec.named_arg_count = j;
    344       if (err)
    345 	/* *invalid_reason has already been set above.  */
    346 	goto bad_format;
    347     }
    348 
    349   result = (struct spec *) xmalloc (sizeof (struct spec));
    350   *result = spec;
    351   return result;
    352 
    353  bad_format:
    354   if (spec.named != NULL)
    355     {
    356       unsigned int i;
    357       for (i = 0; i < spec.named_arg_count; i++)
    358 	free (spec.named[i].name);
    359       free (spec.named);
    360     }
    361   if (spec.unnamed != NULL)
    362     free (spec.unnamed);
    363   return NULL;
    364 }
    365 
    366 static void
    367 format_free (void *descr)
    368 {
    369   struct spec *spec = (struct spec *) descr;
    370 
    371   if (spec->named != NULL)
    372     {
    373       unsigned int i;
    374       for (i = 0; i < spec->named_arg_count; i++)
    375 	free (spec->named[i].name);
    376       free (spec->named);
    377     }
    378   if (spec->unnamed != NULL)
    379     free (spec->unnamed);
    380   free (spec);
    381 }
    382 
    383 static int
    384 format_get_number_of_directives (void *descr)
    385 {
    386   struct spec *spec = (struct spec *) descr;
    387 
    388   return spec->directives;
    389 }
    390 
    391 static bool
    392 format_check (void *msgid_descr, void *msgstr_descr, bool equality,
    393 	      formatstring_error_logger_t error_logger,
    394 	      const char *pretty_msgstr)
    395 {
    396   struct spec *spec1 = (struct spec *) msgid_descr;
    397   struct spec *spec2 = (struct spec *) msgstr_descr;
    398   bool err = false;
    399 
    400   if (spec1->named_arg_count > 0 && spec2->unnamed_arg_count > 0)
    401     {
    402       if (error_logger)
    403 	error_logger (_("format specifications in 'msgid' expect a mapping, those in '%s' expect a tuple"),
    404 		      pretty_msgstr);
    405       err = true;
    406     }
    407   else if (spec1->unnamed_arg_count > 0 && spec2->named_arg_count > 0)
    408     {
    409       if (error_logger)
    410 	error_logger (_("format specifications in 'msgid' expect a tuple, those in '%s' expect a mapping"),
    411 		      pretty_msgstr);
    412       err = true;
    413     }
    414   else
    415     {
    416       if (spec1->named_arg_count + spec2->named_arg_count > 0)
    417 	{
    418 	  unsigned int i, j;
    419 	  unsigned int n1 = spec1->named_arg_count;
    420 	  unsigned int n2 = spec2->named_arg_count;
    421 
    422 	  /* Check the argument names are the same.
    423 	     Both arrays are sorted.  We search for the first difference.  */
    424 	  for (i = 0, j = 0; i < n1 || j < n2; )
    425 	    {
    426 	      int cmp = (i >= n1 ? 1 :
    427 			 j >= n2 ? -1 :
    428 			 strcmp (spec1->named[i].name, spec2->named[j].name));
    429 
    430 	      if (cmp > 0)
    431 		{
    432 		  if (error_logger)
    433 		    error_logger (_("a format specification for argument '%s', as in '%s', doesn't exist in 'msgid'"),
    434 				  spec2->named[j].name, pretty_msgstr);
    435 		  err = true;
    436 		  break;
    437 		}
    438 	      else if (cmp < 0)
    439 		{
    440 		  if (equality)
    441 		    {
    442 		      if (error_logger)
    443 			error_logger (_("a format specification for argument '%s' doesn't exist in '%s'"),
    444 				      spec1->named[i].name, pretty_msgstr);
    445 		      err = true;
    446 		      break;
    447 		    }
    448 		  else
    449 		    i++;
    450 		}
    451 	      else
    452 		j++, i++;
    453 	    }
    454 	  /* Check the argument types are the same.  */
    455 	  if (!err)
    456 	    for (i = 0, j = 0; j < n2; )
    457 	      {
    458 		if (strcmp (spec1->named[i].name, spec2->named[j].name) == 0)
    459 		  {
    460 		    if (spec1->named[i].type != spec2->named[j].type)
    461 		      {
    462 			if (error_logger)
    463 			  error_logger (_("format specifications in 'msgid' and '%s' for argument '%s' are not the same"),
    464 					pretty_msgstr, spec2->named[j].name);
    465 			err = true;
    466 			break;
    467 		      }
    468 		    j++, i++;
    469 		  }
    470 		else
    471 		  i++;
    472 	      }
    473 	}
    474 
    475       if (spec1->unnamed_arg_count + spec2->unnamed_arg_count > 0)
    476 	{
    477 	  unsigned int i;
    478 
    479 	  /* Check the argument types are the same.  */
    480 	  if (equality
    481 	      ? spec1->unnamed_arg_count != spec2->unnamed_arg_count
    482 	      : spec1->unnamed_arg_count < spec2->unnamed_arg_count)
    483 	    {
    484 	      if (error_logger)
    485 		error_logger (_("number of format specifications in 'msgid' and '%s' does not match"),
    486 			      pretty_msgstr);
    487 	      err = true;
    488 	    }
    489 	  else
    490 	    for (i = 0; i < spec2->unnamed_arg_count; i++)
    491 	      if (spec1->unnamed[i].type != spec2->unnamed[i].type)
    492 		{
    493 		  if (error_logger)
    494 		    error_logger (_("format specifications in 'msgid' and '%s' for argument %u are not the same"),
    495 				  pretty_msgstr, i + 1);
    496 		  err = true;
    497 		}
    498 	}
    499     }
    500 
    501   return err;
    502 }
    503 
    504 
    505 struct formatstring_parser formatstring_python =
    506 {
    507   format_parse,
    508   format_free,
    509   format_get_number_of_directives,
    510   NULL,
    511   format_check
    512 };
    513 
    514 
    515 unsigned int
    516 get_python_format_unnamed_arg_count (const char *string)
    517 {
    518   /* Parse the format string.  */
    519   char *invalid_reason = NULL;
    520   struct spec *descr =
    521     (struct spec *) format_parse (string, false, &invalid_reason);
    522 
    523   if (descr != NULL)
    524     {
    525       unsigned int result = descr->unnamed_arg_count;
    526 
    527       format_free (descr);
    528       return result;
    529     }
    530   else
    531     {
    532       free (invalid_reason);
    533       return 0;
    534     }
    535 }
    536 
    537 
    538 #ifdef TEST
    539 
    540 /* Test program: Print the argument list specification returned by
    541    format_parse for strings read from standard input.  */
    542 
    543 #include <stdio.h>
    544 #include "getline.h"
    545 
    546 static void
    547 format_print (void *descr)
    548 {
    549   struct spec *spec = (struct spec *) descr;
    550   unsigned int i;
    551 
    552   if (spec == NULL)
    553     {
    554       printf ("INVALID");
    555       return;
    556     }
    557 
    558   if (spec->named_arg_count > 0)
    559     {
    560       if (spec->unnamed_arg_count > 0)
    561 	abort ();
    562 
    563       printf ("{");
    564       for (i = 0; i < spec->named_arg_count; i++)
    565 	{
    566 	  if (i > 0)
    567 	    printf (", ");
    568 	  printf ("'%s':", spec->named[i].name);
    569 	  switch (spec->named[i].type)
    570 	    {
    571 	    case FAT_ANY:
    572 	      printf ("*");
    573 	      break;
    574 	    case FAT_CHARACTER:
    575 	      printf ("c");
    576 	      break;
    577 	    case FAT_STRING:
    578 	      printf ("s");
    579 	      break;
    580 	    case FAT_INTEGER:
    581 	      printf ("i");
    582 	      break;
    583 	    case FAT_FLOAT:
    584 	      printf ("f");
    585 	      break;
    586 	    default:
    587 	      abort ();
    588 	    }
    589 	}
    590       printf ("}");
    591     }
    592   else
    593     {
    594       printf ("(");
    595       for (i = 0; i < spec->unnamed_arg_count; i++)
    596 	{
    597 	  if (i > 0)
    598 	    printf (" ");
    599 	  switch (spec->unnamed[i].type)
    600 	    {
    601 	    case FAT_ANY:
    602 	      printf ("*");
    603 	      break;
    604 	    case FAT_CHARACTER:
    605 	      printf ("c");
    606 	      break;
    607 	    case FAT_STRING:
    608 	      printf ("s");
    609 	      break;
    610 	    case FAT_INTEGER:
    611 	      printf ("i");
    612 	      break;
    613 	    case FAT_FLOAT:
    614 	      printf ("f");
    615 	      break;
    616 	    default:
    617 	      abort ();
    618 	    }
    619 	}
    620       printf (")");
    621     }
    622 }
    623 
    624 int
    625 main ()
    626 {
    627   for (;;)
    628     {
    629       char *line = NULL;
    630       size_t line_size = 0;
    631       int line_len;
    632       char *invalid_reason;
    633       void *descr;
    634 
    635       line_len = getline (&line, &line_size, stdin);
    636       if (line_len < 0)
    637 	break;
    638       if (line_len > 0 && line[line_len - 1] == '\n')
    639 	line[--line_len] = '\0';
    640 
    641       invalid_reason = NULL;
    642       descr = format_parse (line, false, &invalid_reason);
    643 
    644       format_print (descr);
    645       printf ("\n");
    646       if (descr == NULL)
    647 	printf ("%s\n", invalid_reason);
    648 
    649       free (invalid_reason);
    650       free (line);
    651     }
    652 
    653   return 0;
    654 }
    655 
    656 /*
    657  * For Emacs M-x compile
    658  * Local Variables:
    659  * compile-command: "/bin/sh ../libtool --mode=link gcc -o a.out -static -O -g -Wall -I.. -I../lib -I../intl -DHAVE_CONFIG_H -DTEST format-python.c ../lib/libgettextlib.la"
    660  * End:
    661  */
    662 
    663 #endif /* TEST */
    664