gdb/unittests/array-view-selftests.c

   1 /* Self tests for array_view for GDB, the GNU debugger.
   2
   3    Copyright (C) 2017-2022 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 "gdbsupport/selftest.h"
  22 #include "gdbsupport/array-view.h"
  23 #include <array>
  24 #include <vector>
  25
  26 namespace selftests {
  27 namespace array_view_tests {
  28
  29 /* Triviality checks.  */
  30 #define CHECK_TRAIT(TRAIT)                      \
  31   static_assert (std::TRAIT<gdb::array_view<gdb_byte>>::value, "")
  32
  33 #if HAVE_IS_TRIVIALLY_COPYABLE
  34
  35 CHECK_TRAIT (is_trivially_copyable);
  36 CHECK_TRAIT (is_trivially_move_assignable);
  37 CHECK_TRAIT (is_trivially_move_constructible);
  38 CHECK_TRAIT (is_trivially_destructible);
  39
  40 #endif
  41
  42 #undef CHECK_TRAIT
  43
  44 /* Wrapper around std::is_convertible to make the code using it a bit
  45    shorter.  (With C++14 we'd use a variable template instead.)  */
  46
  47 template<typename From, typename To>
  48 static constexpr bool
  49 is_convertible ()
  50 {
  51   return std::is_convertible<From, To>::value;
  52 }
  53
  54 /* Check for implicit conversion to immutable and mutable views.  */
  55
  56 static constexpr bool
  57 check_convertible ()
  58 {
  59   using T = gdb_byte;
  60   using gdb::array_view;
  61
  62   return (true
  63           /* immutable array_view */
  64           &&  is_convertible<const T (&) [1],   array_view<const T>> ()
  65           &&  is_convertible<T (&) [1],         array_view<const T>> ()
  66           &&  is_convertible<const T,           array_view<const T>> ()
  67           &&  is_convertible<T,                 array_view<const T>> ()
  68
  69           /* mutable array_view */
  70           &&  is_convertible<T (&) [1],         array_view<T>> ()
  71           && !is_convertible<const T (&) [1],   array_view<T>> ()
  72           &&  is_convertible<T,                 array_view<T>> ()
  73           && !is_convertible<const T,           array_view<T>> ()
  74
  75           /* While float is implicitly convertible to gdb_byte, we
  76              don't want implicit float->array_view<gdb_byte>
  77              conversion.  */
  78           && !is_convertible<float,             array_view<const T>> ()
  79           && !is_convertible<float,             array_view<T>> ());
  80 }
  81
  82 static_assert (check_convertible (), "");
  83
  84 namespace no_slicing
  85 {
  86 struct A { int i; };
  87 struct B : A { int j; };
  88 struct C : A { int l; };
  89
  90 /* Check that there's no array->view conversion for arrays of derived types or
  91    subclasses.  */
  92 static constexpr bool
  93 check ()
  94 {
  95   using gdb::array_view;
  96
  97   return (true
  98
  99           /* array->view  */
 100
 101           &&  is_convertible <A (&)[1], array_view<A>> ()
 102           && !is_convertible <B (&)[1], array_view<A>> ()
 103           && !is_convertible <C (&)[1], array_view<A>> ()
 104
 105           && !is_convertible <A (&)[1], array_view<B>> ()
 106           &&  is_convertible <B (&)[1], array_view<B>> ()
 107           && !is_convertible <C (&)[1], array_view<B>> ()
 108
 109           /* elem->view  */
 110
 111           &&  is_convertible <A, array_view<A>> ()
 112           && !is_convertible <B, array_view<A>> ()
 113           && !is_convertible <C, array_view<A>> ()
 114
 115           && !is_convertible <A, array_view<B>> ()
 116           &&  is_convertible <B, array_view<B>> ()
 117           && !is_convertible <C, array_view<B>> ());
 118 }
 119
 120 /* Check that there's no container->view conversion for containers of derived
 121    types or subclasses.  */
 122
 123 template<template<typename ...> class Container>
 124 static constexpr bool
 125 check_ctor_from_container ()
 126 {
 127   using gdb::array_view;
 128
 129   return (    is_convertible <Container<A>, array_view<A>> ()
 130           && !is_convertible <Container<B>, array_view<A>> ()
 131           && !is_convertible <Container<C>, array_view<A>> ()
 132
 133           && !is_convertible <Container<A>, array_view<B>> ()
 134           &&  is_convertible <Container<B>, array_view<B>> ()
 135           && !is_convertible <Container<C>, array_view<B>> ());
 136 }
 137
 138 } /* namespace no_slicing */
 139
 140 /* std::array with only one template argument, so we can pass it to
 141    check_ctor_from_container.  */
 142 template<typename T> using StdArray1 = std::array<T, 1>;
 143
 144 static_assert (no_slicing::check (), "");
 145 static_assert (no_slicing::check_ctor_from_container<std::vector> (), "");
 146 static_assert (no_slicing::check_ctor_from_container<StdArray1> (), "");
 147 static_assert (no_slicing::check_ctor_from_container<gdb::array_view> (), "");
 148
 149 /* Check that array_view implicitly converts from std::vector.  */
 150
 151 static constexpr bool
 152 check_convertible_from_std_vector ()
 153 {
 154   using gdb::array_view;
 155   using T = gdb_byte;
 156
 157   /* Note there's no such thing as std::vector<const T>.  */
 158
 159   return (true
 160           &&  is_convertible <std::vector<T>, array_view<T>> ()
 161           &&  is_convertible <std::vector<T>, array_view<const T>> ());
 162 }
 163
 164 static_assert (check_convertible_from_std_vector (), "");
 165
 166 /* Check that array_view implicitly converts from std::array.  */
 167
 168 static constexpr bool
 169 check_convertible_from_std_array ()
 170 {
 171   using gdb::array_view;
 172   using T = gdb_byte;
 173
 174   /* Note: a non-const T view can't refer to a const T array.  */
 175
 176   return (true
 177           &&  is_convertible <std::array<T, 1>,         array_view<T>> ()
 178           &&  is_convertible <std::array<T, 1>,         array_view<const T>> ()
 179           && !is_convertible <std::array<const T, 1>,   array_view<T>> ()
 180           &&  is_convertible <std::array<const T, 1>,   array_view<const T>> ());
 181 }
 182
 183 static_assert (check_convertible_from_std_array (), "");
 184
 185 /* Check that VIEW views C (a container like std::vector/std::array)
 186    correctly.  */
 187
 188 template<typename View, typename Container>
 189 static bool
 190 check_container_view (const View &view, const Container &c)
 191 {
 192   if (view.empty ())
 193     return false;
 194   if (view.size () != c.size ())
 195     return false;
 196   if (view.data () != c.data ())
 197     return false;
 198   for (size_t i = 0; i < c.size (); i++)
 199     {
 200       if (&view[i] != &c[i])
 201         return false;
 202       if (view[i] != c[i])
 203         return false;
 204     }
 205   return true;
 206 }
 207
 208 /* Check that VIEW views E (an object of the type of a view element)
 209    correctly.  */
 210
 211 template<typename View, typename Elem>
 212 static bool
 213 check_elem_view (const View &view, const Elem &e)
 214 {
 215   if (view.empty ())
 216     return false;
 217   if (view.size () != 1)
 218     return false;
 219   if (view.data () != &e)
 220     return false;
 221   if (&view[0] != &e)
 222     return false;
 223   if (view[0] != e)
 224     return false;
 225   return true;
 226 }
 227
 228 /* Check for operator[].  The first overload is taken iff
 229    'view<T>()[0] = T()' is a valid expression.  */
 230
 231 template<typename View,
 232          typename = decltype (std::declval<View> ()[0]
 233                               = std::declval<typename View::value_type> ())>
 234 static bool
 235 check_op_subscript (const View &view)
 236 {
 237   return true;
 238 }
 239
 240 /* This overload is taken iff 'view<T>()[0] = T()' is not a valid
 241    expression.  */
 242
 243 static bool
 244 check_op_subscript (...)
 245 {
 246   return false;
 247 }
 248
 249 /* Check construction with pointer + size.  This is a template in
 250    order to test both gdb_byte and const gdb_byte.  */
 251
 252 template<typename T>
 253 static void
 254 check_ptr_size_ctor ()
 255 {
 256   T data[] = {0x11, 0x22, 0x33, 0x44};
 257
 258   gdb::array_view<T> view (data + 1, 2);
 259
 260   SELF_CHECK (!view.empty ());
 261   SELF_CHECK (view.size () == 2);
 262   SELF_CHECK (view.data () == &data[1]);
 263   SELF_CHECK (view[0] == data[1]);
 264   SELF_CHECK (view[1] == data[2]);
 265
 266   gdb::array_view<const T> cview (data + 1, 2);
 267   SELF_CHECK (!cview.empty ());
 268   SELF_CHECK (cview.size () == 2);
 269   SELF_CHECK (cview.data () == &data[1]);
 270   SELF_CHECK (cview[0] == data[1]);
 271   SELF_CHECK (cview[1] == data[2]);
 272 }
 273
 274 /* Asserts std::is_constructible.  */
 275
 276 template<typename T, typename... Args>
 277 static constexpr bool
 278 require_not_constructible ()
 279 {
 280   static_assert (!std::is_constructible<T, Args...>::value, "");
 281
 282   /* constexpr functions can't return void in C++11 (N3444).  */
 283   return true;
 284 };
 285
 286 /* Check the array_view<T>(PTR, SIZE) ctor, when T is a pointer.  */
 287
 288 static void
 289 check_ptr_size_ctor2 ()
 290 {
 291   struct A {};
 292   A an_a;
 293
 294   A *array[] = { &an_a };
 295   const A * const carray[] = { &an_a };
 296
 297   gdb::array_view<A *> v1 = {array, ARRAY_SIZE (array)};
 298   gdb::array_view<A *> v2 = {array, (char) ARRAY_SIZE (array)};
 299   gdb::array_view<A * const> v3 = {array, ARRAY_SIZE (array)};
 300   gdb::array_view<const A * const> cv1 = {carray, ARRAY_SIZE (carray)};
 301
 302   require_not_constructible<gdb::array_view<A *>, decltype (carray), size_t> ();
 303
 304   SELF_CHECK (v1[0] == array[0]);
 305   SELF_CHECK (v2[0] == array[0]);
 306   SELF_CHECK (v3[0] == array[0]);
 307
 308   SELF_CHECK (!v1.empty ());
 309   SELF_CHECK (v1.size () == 1);
 310   SELF_CHECK (v1.data () == &array[0]);
 311
 312   SELF_CHECK (cv1[0] == carray[0]);
 313
 314   SELF_CHECK (!cv1.empty ());
 315   SELF_CHECK (cv1.size () == 1);
 316   SELF_CHECK (cv1.data () == &carray[0]);
 317 }
 318
 319 /* Check construction with a pair of pointers.  This is a template in
 320    order to test both gdb_byte and const gdb_byte.  */
 321
 322 template<typename T>
 323 static void
 324 check_ptr_ptr_ctor ()
 325 {
 326   T data[] = {0x11, 0x22, 0x33, 0x44};
 327
 328   gdb::array_view<T> view (data + 1, data + 3);
 329
 330   SELF_CHECK (!view.empty ());
 331   SELF_CHECK (view.size () == 2);
 332   SELF_CHECK (view.data () == &data[1]);
 333   SELF_CHECK (view[0] == data[1]);
 334   SELF_CHECK (view[1] == data[2]);
 335
 336   gdb_byte array[] = {0x11, 0x22, 0x33, 0x44};
 337   const gdb_byte *p1 = array;
 338   gdb_byte *p2 = array + ARRAY_SIZE (array);
 339   gdb::array_view<const gdb_byte> view2 (p1, p2);
 340 }
 341
 342 /* Check construction with a pair of pointers of mixed constness.  */
 343
 344 static void
 345 check_ptr_ptr_mixed_cv ()
 346 {
 347   gdb_byte array[] = {0x11, 0x22, 0x33, 0x44};
 348   const gdb_byte *cp = array;
 349   gdb_byte *p = array;
 350   gdb::array_view<const gdb_byte> view1 (cp, p);
 351   gdb::array_view<const gdb_byte> view2 (p, cp);
 352   SELF_CHECK (view1.empty ());
 353   SELF_CHECK (view2.empty ());
 354 }
 355
 356 /* Check range-for support (i.e., begin()/end()).  This is a template
 357    in order to test both gdb_byte and const gdb_byte.  */
 358
 359 template<typename T>
 360 static void
 361 check_range_for ()
 362 {
 363   T data[] = {1, 2, 3, 4};
 364   gdb::array_view<T> view (data);
 365
 366   typename std::decay<T>::type sum = 0;
 367   for (auto &elem : view)
 368     sum += elem;
 369   SELF_CHECK (sum == 1 + 2 + 3 + 4);
 370 }
 371
 372 /* Entry point.  */
 373
 374 static void
 375 run_tests ()
 376 {
 377   /* Empty views.  */
 378   {
 379     constexpr gdb::array_view<gdb_byte> view1;
 380     constexpr gdb::array_view<const gdb_byte> view2;
 381
 382     static_assert (view1.empty (), "");
 383     static_assert (view1.data () == nullptr, "");
 384     static_assert (view1.size () == 0, "");
 385     static_assert (view2.empty (), "");
 386     static_assert (view2.size () == 0, "");
 387     static_assert (view2.data () == nullptr, "");
 388   }
 389
 390   std::vector<gdb_byte> vec = {0x11, 0x22, 0x33, 0x44 };
 391   std::array<gdb_byte, 4> array = {{0x11, 0x22, 0x33, 0x44}};
 392
 393   /* Various tests of views over std::vector.  */
 394   {
 395     gdb::array_view<gdb_byte> view = vec;
 396     SELF_CHECK (check_container_view (view, vec));
 397     gdb::array_view<const gdb_byte> cview = vec;
 398     SELF_CHECK (check_container_view (cview, vec));
 399   }
 400
 401   /* Likewise, over std::array.  */
 402   {
 403     gdb::array_view<gdb_byte> view = array;
 404     SELF_CHECK (check_container_view (view, array));
 405     gdb::array_view<gdb_byte> cview = array;
 406     SELF_CHECK (check_container_view (cview, array));
 407   }
 408
 409   /* op=(std::vector/std::array/elem) */
 410   {
 411     gdb::array_view<gdb_byte> view;
 412
 413     view = vec;
 414     SELF_CHECK (check_container_view (view, vec));
 415     view = std::move (vec);
 416     SELF_CHECK (check_container_view (view, vec));
 417
 418     view = array;
 419     SELF_CHECK (check_container_view (view, array));
 420     view = std::move (array);
 421     SELF_CHECK (check_container_view (view, array));
 422
 423     gdb_byte elem = 0;
 424     view = elem;
 425     SELF_CHECK (check_elem_view (view, elem));
 426     view = std::move (elem);
 427     SELF_CHECK (check_elem_view (view, elem));
 428   }
 429
 430   /* Test copy/move ctor and mutable->immutable conversion.  */
 431   {
 432     gdb_byte data[] = {0x11, 0x22, 0x33, 0x44};
 433     gdb::array_view<gdb_byte> view1 = data;
 434     gdb::array_view<gdb_byte> view2 = view1;
 435     gdb::array_view<gdb_byte> view3 = std::move (view1);
 436     gdb::array_view<const gdb_byte> cview1 = data;
 437     gdb::array_view<const gdb_byte> cview2 = cview1;
 438     gdb::array_view<const gdb_byte> cview3 = std::move (cview1);
 439     SELF_CHECK (view1[0] == data[0]);
 440     SELF_CHECK (view2[0] == data[0]);
 441     SELF_CHECK (view3[0] == data[0]);
 442     SELF_CHECK (cview1[0] == data[0]);
 443     SELF_CHECK (cview2[0] == data[0]);
 444     SELF_CHECK (cview3[0] == data[0]);
 445   }
 446
 447   /* Same, but op=(view).  */
 448   {
 449     gdb_byte data[] = {0x55, 0x66, 0x77, 0x88};
 450     gdb::array_view<gdb_byte> view1;
 451     gdb::array_view<gdb_byte> view2;
 452     gdb::array_view<gdb_byte> view3;
 453     gdb::array_view<const gdb_byte> cview1;
 454     gdb::array_view<const gdb_byte> cview2;
 455     gdb::array_view<const gdb_byte> cview3;
 456
 457     view1 = data;
 458     view2 = view1;
 459     view3 = std::move (view1);
 460     cview1 = data;
 461     cview2 = cview1;
 462     cview3 = std::move (cview1);
 463     SELF_CHECK (view1[0] == data[0]);
 464     SELF_CHECK (view2[0] == data[0]);
 465     SELF_CHECK (view3[0] == data[0]);
 466     SELF_CHECK (cview1[0] == data[0]);
 467     SELF_CHECK (cview2[0] == data[0]);
 468     SELF_CHECK (cview3[0] == data[0]);
 469   }
 470
 471   /* op[] */
 472   {
 473     std::vector<gdb_byte> vec2 = {0x11, 0x22};
 474     gdb::array_view<gdb_byte> view = vec2;
 475     gdb::array_view<const gdb_byte> cview = vec2;
 476
 477     /* Check that op[] on a non-const view of non-const T returns a
 478        mutable reference.  */
 479     view[0] = 0x33;
 480     SELF_CHECK (vec2[0] == 0x33);
 481
 482     /* OTOH, check that assigning through op[] on a view of const T
 483        wouldn't compile.  */
 484     SELF_CHECK (!check_op_subscript (cview));
 485     /* For completeness.  */
 486     SELF_CHECK (check_op_subscript (view));
 487   }
 488
 489   check_ptr_size_ctor<const gdb_byte> ();
 490   check_ptr_size_ctor<gdb_byte> ();
 491   check_ptr_size_ctor2 ();
 492   check_ptr_ptr_ctor<const gdb_byte> ();
 493   check_ptr_ptr_ctor<gdb_byte> ();
 494   check_ptr_ptr_mixed_cv ();
 495
 496   check_range_for<gdb_byte> ();
 497   check_range_for<const gdb_byte> ();
 498
 499   /* Check that the right ctor overloads are taken when the element is
 500      a container.  */
 501   {
 502     using Vec = std::vector<gdb_byte>;
 503     Vec vecs[3];
 504
 505     gdb::array_view<Vec> view_array = vecs;
 506     SELF_CHECK (view_array.size () == 3);
 507
 508     Vec elem;
 509     gdb::array_view<Vec> view_elem = elem;
 510     SELF_CHECK (view_elem.size () == 1);
 511   }
 512
 513   /* gdb::make_array_view, int length.  */
 514   {
 515     gdb_byte data[] = {0x55, 0x66, 0x77, 0x88};
 516     int len = sizeof (data) / sizeof (data[0]);
 517     auto view = gdb::make_array_view (data, len);
 518
 519     SELF_CHECK (view.data () == data);
 520     SELF_CHECK (view.size () == len);
 521
 522     for (size_t i = 0; i < len; i++)
 523       SELF_CHECK (view[i] == data[i]);
 524   }
 525
 526   /* Test slicing.  */
 527   {
 528     gdb_byte data[] = {0x55, 0x66, 0x77, 0x88, 0x99};
 529     gdb::array_view<gdb_byte> view = data;
 530
 531     {
 532       auto slc = view.slice (1, 3);
 533       SELF_CHECK (slc.data () == data + 1);
 534       SELF_CHECK (slc.size () == 3);
 535       SELF_CHECK (slc[0] == data[1]);
 536       SELF_CHECK (slc[0] == view[1]);
 537     }
 538
 539     {
 540       auto slc = view.slice (2);
 541       SELF_CHECK (slc.data () == data + 2);
 542       SELF_CHECK (slc.size () == 3);
 543       SELF_CHECK (slc[0] == view[2]);
 544       SELF_CHECK (slc[0] == data[2]);
 545     }
 546   }
 547 }
 548
 549 template <typename T>
 550 void
 551 run_copy_test ()
 552 {
 553   /* Test non-overlapping copy.  */
 554   {
 555     const std::vector<T> src_v = {1, 2, 3, 4};
 556     std::vector<T> dest_v (4, -1);
 557
 558     SELF_CHECK (dest_v != src_v);
 559     copy (gdb::array_view<const T> (src_v), gdb::array_view<T> (dest_v));
 560     SELF_CHECK (dest_v == src_v);
 561   }
 562
 563   /* Test overlapping copy, where the source is before the destination.  */
 564   {
 565     std::vector<T> vec = {1, 2, 3, 4, 5, 6, 7, 8};
 566     gdb::array_view<T> v = vec;
 567
 568     copy (v.slice (1, 4),
 569           v.slice (2, 4));
 570
 571     std::vector<T> expected = {1, 2, 2, 3, 4, 5, 7, 8};
 572     SELF_CHECK (vec == expected);
 573   }
 574
 575   /* Test overlapping copy, where the source is after the destination.  */
 576   {
 577     std::vector<T> vec = {1, 2, 3, 4, 5, 6, 7, 8};
 578     gdb::array_view<T> v = vec;
 579
 580     copy (v.slice (2, 4),
 581           v.slice (1, 4));
 582
 583     std::vector<T> expected = {1, 3, 4, 5, 6, 6, 7, 8};
 584     SELF_CHECK (vec == expected);
 585   }
 586
 587   /* Test overlapping copy, where the source is the same as the destination.  */
 588   {
 589     std::vector<T> vec = {1, 2, 3, 4, 5, 6, 7, 8};
 590     gdb::array_view<T> v = vec;
 591
 592     copy (v.slice (2, 4),
 593           v.slice (2, 4));
 594
 595     std::vector<T> expected = {1, 2, 3, 4, 5, 6, 7, 8};
 596     SELF_CHECK (vec == expected);
 597   }
 598 }
 599
 600 /* Class with a non-trivial copy assignment operator, used to test the
 601    array_view copy function.  */
 602 struct foo
 603 {
 604   /* Can be implicitly constructed from an int, such that we can use the same
 605      templated test function to test against array_view<int> and
 606      array_view<foo>.  */
 607   foo (int n)
 608     : n (n)
 609   {}
 610
 611   /* Needed to avoid -Wdeprecated-copy-with-user-provided-copy error with
 612      Clang.  */
 613   foo (const foo &other) = default;
 614
 615   void operator= (const foo &other)
 616   {
 617     this->n = other.n;
 618     this->n_assign_op_called++;
 619   }
 620
 621   bool operator==(const foo &other) const
 622   {
 623     return this->n == other.n;
 624   }
 625
 626   int n;
 627
 628   /* Number of times the assignment operator has been called.  */
 629   static int n_assign_op_called;
 630 };
 631
 632 int foo::n_assign_op_called = 0;
 633
 634 /* Test the array_view copy free function.  */
 635
 636 static void
 637 run_copy_tests ()
 638 {
 639   /* Test with a trivial type.  */
 640   run_copy_test<int> ();
 641
 642   /* Test with a non-trivial type.  */
 643   foo::n_assign_op_called = 0;
 644   run_copy_test<foo> ();
 645
 646   /* Make sure that for the non-trivial type foo, the assignment operator was
 647      called an amount of times that makes sense.  */
 648   SELF_CHECK (foo::n_assign_op_called == 12);
 649 }
 650
 651 } /* namespace array_view_tests */
 652 } /* namespace selftests */
 653
 654 void _initialize_array_view_selftests ();
 655 void
 656 _initialize_array_view_selftests ()
 657 {
 658   selftests::register_test ("array_view",
 659                             selftests::array_view_tests::run_tests);
 660   selftests::register_test ("array_view-copy",
 661                             selftests::array_view_tests::run_copy_tests);
 662 }