gcc/json.cc

   1 /* JSON trees
   2    Copyright (C) 2017-2021 Free Software Foundation, Inc.
   3    Contributed by David Malcolm <dmalcolm@redhat.com>.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "json.h"
  25 #include "pretty-print.h"
  26 #include "math.h"
  27 #include "selftest.h"
  28
  29 using namespace json;
  30
  31 /* class json::value.  */
  32
  33 /* Dump this json::value tree to OUTF.
  34    No formatting is done.  There are no guarantees about the order
  35    in which the key/value pairs of json::objects are printed.  */
  36
  37 void
  38 value::dump (FILE *outf) const
  39 {
  40   pretty_printer pp;
  41   pp_buffer (&pp)->stream = outf;
  42   print (&pp);
  43   pp_flush (&pp);
  44 }
  45
  46 /* class json::object, a subclass of json::value, representing
  47    an unordered collection of key/value pairs.  */
  48
  49 /* json:object's dtor.  */
  50
  51 object::~object ()
  52 {
  53   for (map_t::iterator it = m_map.begin (); it != m_map.end (); ++it)
  54     {
  55       free (const_cast <char *>((*it).first));
  56       delete ((*it).second);
  57     }
  58 }
  59
  60 /* Implementation of json::value::print for json::object.  */
  61
  62 void
  63 object::print (pretty_printer *pp) const
  64 {
  65   /* Note that the order is not guaranteed.  */
  66   pp_character (pp, '{');
  67   for (map_t::iterator it = m_map.begin (); it != m_map.end (); ++it)
  68     {
  69       if (it != m_map.begin ())
  70         pp_string (pp, ", ");
  71       const char *key = const_cast <char *>((*it).first);
  72       value *value = (*it).second;
  73       pp_doublequote (pp);
  74       pp_string (pp, key); // FIXME: escaping?
  75       pp_doublequote (pp);
  76       pp_string (pp, ": ");
  77       value->print (pp);
  78     }
  79   pp_character (pp, '}');
  80 }
  81
  82 /* Set the json::value * for KEY, taking ownership of V
  83    (and taking a copy of KEY if necessary).  */
  84
  85 void
  86 object::set (const char *key, value *v)
  87 {
  88   gcc_assert (key);
  89   gcc_assert (v);
  90
  91   value **ptr = m_map.get (key);
  92   if (ptr)
  93     {
  94       /* If the key is already present, delete the existing value
  95          and overwrite it.  */
  96       delete *ptr;
  97       *ptr = v;
  98     }
  99   else
 100     /* If the key wasn't already present, take a copy of the key,
 101        and store the value.  */
 102     m_map.put (xstrdup (key), v);
 103 }
 104
 105 /* Get the json::value * for KEY.
 106
 107    The object retains ownership of the value.  */
 108
 109 value *
 110 object::get (const char *key) const
 111 {
 112   gcc_assert (key);
 113
 114   value **ptr = const_cast <map_t &> (m_map).get (key);
 115   if (ptr)
 116     return *ptr;
 117   else
 118     return NULL;
 119 }
 120
 121 /* class json::array, a subclass of json::value, representing
 122    an ordered collection of values.  */
 123
 124 /* json::array's dtor.  */
 125
 126 array::~array ()
 127 {
 128   unsigned i;
 129   value *v;
 130   FOR_EACH_VEC_ELT (m_elements, i, v)
 131     delete v;
 132 }
 133
 134 /* Implementation of json::value::print for json::array.  */
 135
 136 void
 137 array::print (pretty_printer *pp) const
 138 {
 139   pp_character (pp, '[');
 140   unsigned i;
 141   value *v;
 142   FOR_EACH_VEC_ELT (m_elements, i, v)
 143     {
 144       if (i)
 145         pp_string (pp, ", ");
 146       v->print (pp);
 147     }
 148   pp_character (pp, ']');
 149 }
 150
 151 /* Append non-NULL value V to a json::array, taking ownership of V.  */
 152
 153 void
 154 array::append (value *v)
 155 {
 156   gcc_assert (v);
 157   m_elements.safe_push (v);
 158 }
 159
 160 /* class json::float_number, a subclass of json::value, wrapping a double.  */
 161
 162 /* Implementation of json::value::print for json::float_number.  */
 163
 164 void
 165 float_number::print (pretty_printer *pp) const
 166 {
 167   char tmp[1024];
 168   snprintf (tmp, sizeof (tmp), "%g", m_value);
 169   pp_string (pp, tmp);
 170 }
 171
 172 /* class json::integer_number, a subclass of json::value, wrapping a long.  */
 173
 174 /* Implementation of json::value::print for json::integer_number.  */
 175
 176 void
 177 integer_number::print (pretty_printer *pp) const
 178 {
 179   char tmp[1024];
 180   snprintf (tmp, sizeof (tmp), "%ld", m_value);
 181   pp_string (pp, tmp);
 182 }
 183
 184
 185 /* class json::string, a subclass of json::value.  */
 186
 187 /* json::string's ctor.  */
 188
 189 string::string (const char *utf8)
 190 {
 191   gcc_assert (utf8);
 192   m_utf8 = xstrdup (utf8);
 193 }
 194
 195 /* Implementation of json::value::print for json::string.  */
 196
 197 void
 198 string::print (pretty_printer *pp) const
 199 {
 200   pp_character (pp, '"');
 201   for (const char *ptr = m_utf8; *ptr; ptr++)
 202     {
 203       char ch = *ptr;
 204       switch (ch)
 205         {
 206         case '"':
 207           pp_string (pp, "\\\"");
 208           break;
 209         case '\\':
 210           pp_string (pp, "\\n");
 211           break;
 212         case '\b':
 213           pp_string (pp, "\\b");
 214           break;
 215         case '\f':
 216           pp_string (pp, "\\f");
 217           break;
 218         case '\n':
 219           pp_string (pp, "\\n");
 220           break;
 221         case '\r':
 222           pp_string (pp, "\\r");
 223           break;
 224         case '\t':
 225           pp_string (pp, "\\t");
 226           break;
 227
 228         default:
 229           pp_character (pp, ch);
 230         }
 231     }
 232   pp_character (pp, '"');
 233 }
 234
 235 /* class json::literal, a subclass of json::value.  */
 236
 237 /* Implementation of json::value::print for json::literal.  */
 238
 239 void
 240 literal::print (pretty_printer *pp) const
 241 {
 242   switch (m_kind)
 243     {
 244     case JSON_TRUE:
 245       pp_string (pp, "true");
 246       break;
 247     case JSON_FALSE:
 248       pp_string (pp, "false");
 249       break;
 250     case JSON_NULL:
 251       pp_string (pp, "null");
 252       break;
 253     default:
 254       gcc_unreachable ();
 255     }
 256 }
 257
 258 \f
 259 #if CHECKING_P
 260
 261 namespace selftest {
 262
 263 /* Selftests.  */
 264
 265 /* Verify that JV->print () prints EXPECTED_JSON.  */
 266
 267 static void
 268 assert_print_eq (const json::value &jv, const char *expected_json)
 269 {
 270   pretty_printer pp;
 271   jv.print (&pp);
 272   ASSERT_STREQ (expected_json, pp_formatted_text (&pp));
 273 }
 274
 275 /* Verify that object::get works as expected.  */
 276
 277 static void
 278 test_object_get ()
 279 {
 280   object obj;
 281   value *val = new json::string ("value");
 282   obj.set ("foo", val);
 283   ASSERT_EQ (obj.get ("foo"), val);
 284   ASSERT_EQ (obj.get ("not-present"), NULL);
 285 }
 286
 287 /* Verify that JSON objects are written correctly.  We can't test more than
 288    one key/value pair, as we don't impose a guaranteed ordering.  */
 289
 290 static void
 291 test_writing_objects ()
 292 {
 293   object obj;
 294   obj.set ("foo", new json::string ("bar"));
 295   assert_print_eq (obj, "{\"foo\": \"bar\"}");
 296 }
 297
 298 /* Verify that JSON arrays are written correctly.  */
 299
 300 static void
 301 test_writing_arrays ()
 302 {
 303   array arr;
 304   assert_print_eq (arr, "[]");
 305
 306   arr.append (new json::string ("foo"));
 307   assert_print_eq (arr, "[\"foo\"]");
 308
 309   arr.append (new json::string ("bar"));
 310   assert_print_eq (arr, "[\"foo\", \"bar\"]");
 311 }
 312
 313 /* Verify that JSON numbers are written correctly.  */
 314
 315 static void
 316 test_writing_float_numbers ()
 317 {
 318   assert_print_eq (float_number (0), "0");
 319   assert_print_eq (float_number (42), "42");
 320   assert_print_eq (float_number (-100), "-100");
 321   assert_print_eq (float_number (123456789), "1.23457e+08");
 322 }
 323
 324 static void
 325 test_writing_integer_numbers ()
 326 {
 327   assert_print_eq (integer_number (0), "0");
 328   assert_print_eq (integer_number (42), "42");
 329   assert_print_eq (integer_number (-100), "-100");
 330   assert_print_eq (integer_number (123456789), "123456789");
 331   assert_print_eq (integer_number (-123456789), "-123456789");
 332 }
 333
 334 /* Verify that JSON strings are written correctly.  */
 335
 336 static void
 337 test_writing_strings ()
 338 {
 339   string foo ("foo");
 340   assert_print_eq (foo, "\"foo\"");
 341
 342   string contains_quotes ("before \"quoted\" after");
 343   assert_print_eq (contains_quotes, "\"before \\\"quoted\\\" after\"");
 344 }
 345
 346 /* Verify that JSON literals are written correctly.  */
 347
 348 static void
 349 test_writing_literals ()
 350 {
 351   assert_print_eq (literal (JSON_TRUE), "true");
 352   assert_print_eq (literal (JSON_FALSE), "false");
 353   assert_print_eq (literal (JSON_NULL), "null");
 354
 355   assert_print_eq (literal (true), "true");
 356   assert_print_eq (literal (false), "false");
 357 }
 358
 359 /* Run all of the selftests within this file.  */
 360
 361 void
 362 json_cc_tests ()
 363 {
 364   test_object_get ();
 365   test_writing_objects ();
 366   test_writing_arrays ();
 367   test_writing_float_numbers ();
 368   test_writing_integer_numbers ();
 369   test_writing_strings ();
 370   test_writing_literals ();
 371 }
 372
 373 } // namespace selftest
 374
 375 #endif /* #if CHECKING_P */