gdb/unittests/array-view-selftests.c

   1 /* Self tests for array_view for GDB, the GNU debugger.
   2
   3    Copyright (C) 2017-2019 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "common/selftest.h"
  22 #include "common/array-view.h"
  23 #include <array>
  24
  25 namespace selftests {
  26 namespace array_view_tests {
  27
  28 /* Triviality checks.  */
  29 #define CHECK_TRAIT(TRAIT)                      \
  30   static_assert (std::TRAIT<gdb::array_view<gdb_byte>>::value, "")
  31
  32 #if HAVE_IS_TRIVIALLY_COPYABLE
  33
  34 CHECK_TRAIT (is_trivially_copyable);
  35 CHECK_TRAIT (is_trivially_move_assignable);
  36 CHECK_TRAIT (is_trivially_move_constructible);
  37 CHECK_TRAIT (is_trivially_destructible);
  38
  39 #endif
  40
  41 #undef CHECK_TRAIT
  42
  43 /* Wrapper around std::is_convertible to make the code using it a bit
  44    shorter.  (With C++14 we'd use a variable template instead.)  */
  45
  46 template<typename From, typename To>
  47 static constexpr bool
  48 is_convertible ()
  49 {
  50   return std::is_convertible<From, To>::value;
  51 }
  52
  53 /* Check for implicit conversion to immutable and mutable views.  */
  54
  55 static constexpr bool
  56 check_convertible ()
  57 {
  58   using T = gdb_byte;
  59   using gdb::array_view;
  60
  61   return (true
  62           /* immutable array_view */
  63           &&  is_convertible<const T (&) [1],   array_view<const T>> ()
  64           &&  is_convertible<T (&) [1],         array_view<const T>> ()
  65           &&  is_convertible<const T,           array_view<const T>> ()
  66           &&  is_convertible<T,                 array_view<const T>> ()
  67
  68           /* mutable array_view */
  69           &&  is_convertible<T (&) [1],         array_view<T>> ()
  70           && !is_convertible<const T (&) [1],   array_view<T>> ()
  71           &&  is_convertible<T,                 array_view<T>> ()
  72           && !is_convertible<const T,           array_view<T>> ()
  73
  74           /* While float is implicitly convertible to gdb_byte, we
  75              don't want implicit float->array_view<gdb_byte>
  76              conversion.  */
  77           && !is_convertible<float,             array_view<const T>> ()
  78           && !is_convertible<float,             array_view<T>> ());
  79 }
  80
  81 static_assert (check_convertible (), "");
  82
  83 namespace no_slicing
  84 {
  85 struct A { int i; };
  86 struct B : A { int j; };
  87 struct C : A { int l; };
  88
  89 /* Check that there's no array->view conversion for arrays of derived
  90    types or subclasses.  */
  91 static constexpr bool
  92 check ()
  93 {
  94   using gdb::array_view;
  95
  96   return (true
  97
  98           /* array->view  */
  99
 100           &&  is_convertible <A (&)[1], array_view<A>> ()
 101           && !is_convertible <B (&)[1], array_view<A>> ()
 102           && !is_convertible <C (&)[1], array_view<A>> ()
 103
 104           && !is_convertible <A (&)[1], array_view<B>> ()
 105           &&  is_convertible <B (&)[1], array_view<B>> ()
 106           && !is_convertible <C (&)[1], array_view<B>> ()
 107
 108           /* elem->view  */
 109
 110           &&  is_convertible <A, array_view<A>> ()
 111           && !is_convertible <B, array_view<A>> ()
 112           && !is_convertible <C, array_view<A>> ()
 113
 114           && !is_convertible <A, array_view<B>> ()
 115           &&  is_convertible <B, array_view<B>> ()
 116           && !is_convertible <C, array_view<B>> ());
 117 }
 118
 119 } /* namespace no_slicing */
 120
 121 static_assert (no_slicing::check (), "");
 122
 123 /* Check that array_view implicitly converts from std::vector.  */
 124
 125 static constexpr bool
 126 check_convertible_from_std_vector ()
 127 {
 128   using gdb::array_view;
 129   using T = gdb_byte;
 130
 131   /* Note there's no such thing as std::vector<const T>.  */
 132
 133   return (true
 134           &&  is_convertible <std::vector<T>, array_view<T>> ()
 135           &&  is_convertible <std::vector<T>, array_view<const T>> ());
 136 }
 137
 138 static_assert (check_convertible_from_std_vector (), "");
 139
 140 /* Check that array_view implicitly converts from std::array.  */
 141
 142 static constexpr bool
 143 check_convertible_from_std_array ()
 144 {
 145   using gdb::array_view;
 146   using T = gdb_byte;
 147
 148   /* Note: a non-const T view can't refer to a const T array.  */
 149
 150   return (true
 151           &&  is_convertible <std::array<T, 1>,         array_view<T>> ()
 152           &&  is_convertible <std::array<T, 1>,         array_view<const T>> ()
 153           && !is_convertible <std::array<const T, 1>,   array_view<T>> ()
 154           &&  is_convertible <std::array<const T, 1>,   array_view<const T>> ());
 155 }
 156
 157 static_assert (check_convertible_from_std_array (), "");
 158
 159 /* Check that VIEW views C (a container like std::vector/std::array)
 160    correctly.  */
 161
 162 template<typename View, typename Container>
 163 static bool
 164 check_container_view (const View &view, const Container &c)
 165 {
 166   if (view.empty ())
 167     return false;
 168   if (view.size () != c.size ())
 169     return false;
 170   if (view.data () != c.data ())
 171     return false;
 172   for (size_t i = 0; i < c.size (); i++)
 173     {
 174       if (&view[i] != &c[i])
 175         return false;
 176       if (view[i] != c[i])
 177         return false;
 178     }
 179   return true;
 180 }
 181
 182 /* Check that VIEW views E (an object of the type of a view element)
 183    correctly.  */
 184
 185 template<typename View, typename Elem>
 186 static bool
 187 check_elem_view (const View &view, const Elem &e)
 188 {
 189   if (view.empty ())
 190     return false;
 191   if (view.size () != 1)
 192     return false;
 193   if (view.data () != &e)
 194     return false;
 195   if (&view[0] != &e)
 196     return false;
 197   if (view[0] != e)
 198     return false;
 199   return true;
 200 }
 201
 202 /* Check for operator[].  The first overload is taken iff
 203    'view<T>()[0] = T()' is a valid expression.  */
 204
 205 template<typename View,
 206          typename = decltype (std::declval<View> ()[0]
 207                               = std::declval<typename View::value_type> ())>
 208 static bool
 209 check_op_subscript (const View &view)
 210 {
 211   return true;
 212 }
 213
 214 /* This overload is taken iff 'view<T>()[0] = T()' is not a valid
 215    expression.  */
 216
 217 static bool
 218 check_op_subscript (...)
 219 {
 220   return false;
 221 }
 222
 223 /* Check construction with pointer + size.  This is a template in
 224    order to test both gdb_byte and const gdb_byte.  */
 225
 226 template<typename T>
 227 static void
 228 check_ptr_size_ctor ()
 229 {
 230   T data[] = {0x11, 0x22, 0x33, 0x44};
 231
 232   gdb::array_view<T> view (data + 1, 2);
 233
 234   SELF_CHECK (!view.empty ());
 235   SELF_CHECK (view.size () == 2);
 236   SELF_CHECK (view.data () == &data[1]);
 237   SELF_CHECK (view[0] == data[1]);
 238   SELF_CHECK (view[1] == data[2]);
 239
 240   gdb::array_view<const T> cview (data + 1, 2);
 241   SELF_CHECK (!cview.empty ());
 242   SELF_CHECK (cview.size () == 2);
 243   SELF_CHECK (cview.data () == &data[1]);
 244   SELF_CHECK (cview[0] == data[1]);
 245   SELF_CHECK (cview[1] == data[2]);
 246 }
 247
 248 /* Asserts std::is_constructible.  */
 249
 250 template<typename T, typename... Args>
 251 static constexpr bool
 252 require_not_constructible ()
 253 {
 254   static_assert (!std::is_constructible<T, Args...>::value, "");
 255
 256   /* constexpr functions can't return void in C++11 (N3444).  */
 257   return true;
 258 };
 259
 260 /* Check the array_view<T>(PTR, SIZE) ctor, when T is a pointer.  */
 261
 262 void
 263 check_ptr_size_ctor2 ()
 264 {
 265   struct A {};
 266   A an_a;
 267
 268   A *array[] = { &an_a };
 269   const A * const carray[] = { &an_a };
 270
 271   gdb::array_view<A *> v1 = {array, ARRAY_SIZE (array)};
 272   gdb::array_view<A *> v2 = {array, (char) ARRAY_SIZE (array)};
 273   gdb::array_view<A * const> v3 = {array, ARRAY_SIZE (array)};
 274   gdb::array_view<const A * const> cv1 = {carray, ARRAY_SIZE (carray)};
 275
 276   require_not_constructible<gdb::array_view<A *>, decltype (carray), size_t> ();
 277
 278   SELF_CHECK (v1[0] == array[0]);
 279   SELF_CHECK (v2[0] == array[0]);
 280   SELF_CHECK (v3[0] == array[0]);
 281
 282   SELF_CHECK (!v1.empty ());
 283   SELF_CHECK (v1.size () == 1);
 284   SELF_CHECK (v1.data () == &array[0]);
 285
 286   SELF_CHECK (cv1[0] == carray[0]);
 287
 288   SELF_CHECK (!cv1.empty ());
 289   SELF_CHECK (cv1.size () == 1);
 290   SELF_CHECK (cv1.data () == &carray[0]);
 291 }
 292
 293 /* Check construction with a pair of pointers.  This is a template in
 294    order to test both gdb_byte and const gdb_byte.  */
 295
 296 template<typename T>
 297 static void
 298 check_ptr_ptr_ctor ()
 299 {
 300   T data[] = {0x11, 0x22, 0x33, 0x44};
 301
 302   gdb::array_view<T> view (data + 1, data + 3);
 303
 304   SELF_CHECK (!view.empty ());
 305   SELF_CHECK (view.size () == 2);
 306   SELF_CHECK (view.data () == &data[1]);
 307   SELF_CHECK (view[0] == data[1]);
 308   SELF_CHECK (view[1] == data[2]);
 309
 310   gdb_byte array[] = {0x11, 0x22, 0x33, 0x44};
 311   const gdb_byte *p1 = array;
 312   gdb_byte *p2 = array + ARRAY_SIZE (array);
 313   gdb::array_view<const gdb_byte> view2 (p1, p2);
 314 }
 315
 316 /* Check construction with a pair of pointers of mixed constness.  */
 317
 318 static void
 319 check_ptr_ptr_mixed_cv ()
 320 {
 321   gdb_byte array[] = {0x11, 0x22, 0x33, 0x44};
 322   const gdb_byte *cp = array;
 323   gdb_byte *p = array;
 324   gdb::array_view<const gdb_byte> view1 (cp, p);
 325   gdb::array_view<const gdb_byte> view2 (p, cp);
 326   SELF_CHECK (view1.empty ());
 327   SELF_CHECK (view2.empty ());
 328 }
 329
 330 /* Check range-for support (i.e., begin()/end()).  This is a template
 331    in order to test both gdb_byte and const gdb_byte.  */
 332
 333 template<typename T>
 334 static void
 335 check_range_for ()
 336 {
 337   T data[] = {1, 2, 3, 4};
 338   gdb::array_view<T> view (data);
 339
 340   typename std::decay<T>::type sum = 0;
 341   for (auto &elem : view)
 342     sum += elem;
 343   SELF_CHECK (sum == 1 + 2 + 3 + 4);
 344 }
 345
 346 /* Entry point.  */
 347
 348 static void
 349 run_tests ()
 350 {
 351   /* Empty views.  */
 352   {
 353     constexpr gdb::array_view<gdb_byte> view1;
 354     constexpr gdb::array_view<const gdb_byte> view2;
 355
 356     static_assert (view1.empty (), "");
 357     static_assert (view1.data () == nullptr, "");
 358     static_assert (view1.size () == 0, "");
 359     static_assert (view2.empty (), "");
 360     static_assert (view2.size () == 0, "");
 361     static_assert (view2.data () == nullptr, "");
 362   }
 363
 364   std::vector<gdb_byte> vec = {0x11, 0x22, 0x33, 0x44 };
 365   std::array<gdb_byte, 4> array = {{0x11, 0x22, 0x33, 0x44}};
 366
 367   /* Various tests of views over std::vector.  */
 368   {
 369     gdb::array_view<gdb_byte> view = vec;
 370     SELF_CHECK (check_container_view (view, vec));
 371     gdb::array_view<const gdb_byte> cview = vec;
 372     SELF_CHECK (check_container_view (cview, vec));
 373   }
 374
 375   /* Likewise, over std::array.  */
 376   {
 377     gdb::array_view<gdb_byte> view = array;
 378     SELF_CHECK (check_container_view (view, array));
 379     gdb::array_view<gdb_byte> cview = array;
 380     SELF_CHECK (check_container_view (cview, array));
 381   }
 382
 383   /* op=(std::vector/std::array/elem) */
 384   {
 385     gdb::array_view<gdb_byte> view;
 386
 387     view = vec;
 388     SELF_CHECK (check_container_view (view, vec));
 389     view = std::move (vec);
 390     SELF_CHECK (check_container_view (view, vec));
 391
 392     view = array;
 393     SELF_CHECK (check_container_view (view, array));
 394     view = std::move (array);
 395     SELF_CHECK (check_container_view (view, array));
 396
 397     gdb_byte elem = 0;
 398     view = elem;
 399     SELF_CHECK (check_elem_view (view, elem));
 400     view = std::move (elem);
 401     SELF_CHECK (check_elem_view (view, elem));
 402   }
 403
 404   /* Test copy/move ctor and mutable->immutable conversion.  */
 405   {
 406     gdb_byte data[] = {0x11, 0x22, 0x33, 0x44};
 407     gdb::array_view<gdb_byte> view1 = data;
 408     gdb::array_view<gdb_byte> view2 = view1;
 409     gdb::array_view<gdb_byte> view3 = std::move (view1);
 410     gdb::array_view<const gdb_byte> cview1 = data;
 411     gdb::array_view<const gdb_byte> cview2 = cview1;
 412     gdb::array_view<const gdb_byte> cview3 = std::move (cview1);
 413     SELF_CHECK (view1[0] == data[0]);
 414     SELF_CHECK (view2[0] == data[0]);
 415     SELF_CHECK (view3[0] == data[0]);
 416     SELF_CHECK (cview1[0] == data[0]);
 417     SELF_CHECK (cview2[0] == data[0]);
 418     SELF_CHECK (cview3[0] == data[0]);
 419   }
 420
 421   /* Same, but op=(view).  */
 422   {
 423     gdb_byte data[] = {0x55, 0x66, 0x77, 0x88};
 424     gdb::array_view<gdb_byte> view1;
 425     gdb::array_view<gdb_byte> view2;
 426     gdb::array_view<gdb_byte> view3;
 427     gdb::array_view<const gdb_byte> cview1;
 428     gdb::array_view<const gdb_byte> cview2;
 429     gdb::array_view<const gdb_byte> cview3;
 430
 431     view1 = data;
 432     view2 = view1;
 433     view3 = std::move (view1);
 434     cview1 = data;
 435     cview2 = cview1;
 436     cview3 = std::move (cview1);
 437     SELF_CHECK (view1[0] == data[0]);
 438     SELF_CHECK (view2[0] == data[0]);
 439     SELF_CHECK (view3[0] == data[0]);
 440     SELF_CHECK (cview1[0] == data[0]);
 441     SELF_CHECK (cview2[0] == data[0]);
 442     SELF_CHECK (cview3[0] == data[0]);
 443   }
 444
 445   /* op[] */
 446   {
 447     std::vector<gdb_byte> vec2 = {0x11, 0x22};
 448     gdb::array_view<gdb_byte> view = vec2;
 449     gdb::array_view<const gdb_byte> cview = vec2;
 450
 451     /* Check that op[] on a non-const view of non-const T returns a
 452        mutable reference.  */
 453     view[0] = 0x33;
 454     SELF_CHECK (vec2[0] == 0x33);
 455
 456     /* OTOH, check that assigning through op[] on a view of const T
 457        wouldn't compile.  */
 458     SELF_CHECK (!check_op_subscript (cview));
 459     /* For completeness.  */
 460     SELF_CHECK (check_op_subscript (view));
 461   }
 462
 463   check_ptr_size_ctor<const gdb_byte> ();
 464   check_ptr_size_ctor<gdb_byte> ();
 465   check_ptr_size_ctor2 ();
 466   check_ptr_ptr_ctor<const gdb_byte> ();
 467   check_ptr_ptr_ctor<gdb_byte> ();
 468   check_ptr_ptr_mixed_cv ();
 469
 470   check_range_for<gdb_byte> ();
 471   check_range_for<const gdb_byte> ();
 472
 473   /* Check that the right ctor overloads are taken when the element is
 474      a container.  */
 475   {
 476     using Vec = std::vector<gdb_byte>;
 477     Vec vecs[3];
 478
 479     gdb::array_view<Vec> view_array = vecs;
 480     SELF_CHECK (view_array.size () == 3);
 481
 482     Vec elem;
 483     gdb::array_view<Vec> view_elem = elem;
 484     SELF_CHECK (view_elem.size () == 1);
 485   }
 486
 487   /* gdb::make_array_view, int length.  */
 488   {
 489     gdb_byte data[] = {0x55, 0x66, 0x77, 0x88};
 490     int len = sizeof (data) / sizeof (data[0]);
 491     auto view = gdb::make_array_view (data, len);
 492
 493     SELF_CHECK (view.data () == data);
 494     SELF_CHECK (view.size () == len);
 495
 496     for (size_t i = 0; i < len; i++)
 497       SELF_CHECK (view[i] == data[i]);
 498   }
 499
 500   /* Test slicing.  */
 501   {
 502     gdb_byte data[] = {0x55, 0x66, 0x77, 0x88, 0x99};
 503     gdb::array_view<gdb_byte> view = data;
 504
 505     {
 506       auto slc = view.slice (1, 3);
 507       SELF_CHECK (slc.data () == data + 1);
 508       SELF_CHECK (slc.size () == 3);
 509       SELF_CHECK (slc[0] == data[1]);
 510       SELF_CHECK (slc[0] == view[1]);
 511     }
 512
 513     {
 514       auto slc = view.slice (2);
 515       SELF_CHECK (slc.data () == data + 2);
 516       SELF_CHECK (slc.size () == 3);
 517       SELF_CHECK (slc[0] == view[2]);
 518       SELF_CHECK (slc[0] == data[2]);
 519     }
 520   }
 521 }
 522
 523 } /* namespace array_view_tests */
 524 } /* namespace selftests */
 525
 526 void
 527 _initialize_array_view_selftests ()
 528 {
 529   selftests::register_test ("array_view",
 530                             selftests::array_view_tests::run_tests);
 531 }