gcc/function-tests.c

   1 /* Unit tests for function-handling.
   2    Copyright (C) 2015-2017 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include "tm.h"
  24 #include "opts.h"
  25 #include "signop.h"
  26 #include "hash-set.h"
  27 #include "fixed-value.h"
  28 #include "alias.h"
  29 #include "flags.h"
  30 #include "symtab.h"
  31 #include "tree-core.h"
  32 #include "stor-layout.h"
  33 #include "tree.h"
  34 #include "stringpool.h"
  35 #include "stor-layout.h"
  36 #include "rtl.h"
  37 #include "predict.h"
  38 #include "vec.h"
  39 #include "hashtab.h"
  40 #include "hash-set.h"
  41 #include "machmode.h"
  42 #include "hard-reg-set.h"
  43 #include "input.h"
  44 #include "function.h"
  45 #include "dominance.h"
  46 #include "cfg.h"
  47 #include "cfganal.h"
  48 #include "basic-block.h"
  49 #include "tree-ssa-alias.h"
  50 #include "internal-fn.h"
  51 #include "gimple-fold.h"
  52 #include "gimple-expr.h"
  53 #include "toplev.h"
  54 #include "print-tree.h"
  55 #include "tree-iterator.h"
  56 #include "gimplify.h"
  57 #include "tree-cfg.h"
  58 #include "basic-block.h"
  59 #include "double-int.h"
  60 #include "alias.h"
  61 #include "symtab.h"
  62 #include "wide-int.h"
  63 #include "inchash.h"
  64 #include "tree.h"
  65 #include "fold-const.h"
  66 #include "stor-layout.h"
  67 #include "stmt.h"
  68 #include "hash-table.h"
  69 #include "tree-ssa-alias.h"
  70 #include "internal-fn.h"
  71 #include "gimple-expr.h"
  72 #include "is-a.h"
  73 #include "gimple.h"
  74 #include "tree-pass.h"
  75 #include "context.h"
  76 #include "hash-map.h"
  77 #include "plugin-api.h"
  78 #include "ipa-ref.h"
  79 #include "cgraph.h"
  80 #include "selftest.h"
  81 #include "print-rtl.h"
  82
  83 #if CHECKING_P
  84
  85 namespace selftest {
  86
  87 /* Helper function for selftests of function-creation.  */
  88
  89 static tree
  90 make_fndecl (tree return_type,
  91              const char *name,
  92              vec <tree> &param_types,
  93              bool is_variadic = false)
  94 {
  95   tree fn_type;
  96   if (is_variadic)
  97     fn_type = build_varargs_function_type_array (return_type,
  98                                                  param_types.length (),
  99                                                  param_types.address ());
 100   else
 101     fn_type = build_function_type_array (return_type,
 102                                          param_types.length (),
 103                                          param_types.address ());
 104   /* FIXME: this uses input_location: */
 105   tree fndecl = build_fn_decl (name, fn_type);
 106
 107   return fndecl;
 108 }
 109
 110 /* Verify creating a function declaration equivalent to the following
 111      int test_fndecl_int_void (void);
 112    C declaration.  */
 113
 114 static void
 115 test_fndecl_int_void ()
 116 {
 117   auto_vec <tree> param_types;
 118   const char *name = "test_fndecl_int_void";
 119   tree fndecl = make_fndecl (integer_type_node,
 120                              name,
 121                              param_types);
 122   ASSERT_TRUE (fndecl != NULL);
 123
 124   /* Verify name of decl.  */
 125   tree declname = DECL_NAME (fndecl);
 126   ASSERT_TRUE (declname != NULL);
 127   ASSERT_EQ (IDENTIFIER_NODE, TREE_CODE (declname));
 128   /* We expect it to use a *copy* of the string we passed in.  */
 129   const char *identifier_ptr = IDENTIFIER_POINTER (declname);
 130   ASSERT_NE (name, identifier_ptr);
 131   ASSERT_EQ (0, strcmp ("test_fndecl_int_void", identifier_ptr));
 132
 133   /* Verify type of fndecl.  */
 134   ASSERT_EQ (FUNCTION_DECL, TREE_CODE (fndecl));
 135   tree fntype = TREE_TYPE (fndecl);
 136   ASSERT_EQ (FUNCTION_TYPE, TREE_CODE (fntype));
 137
 138   /* Verify return type.  */
 139   ASSERT_EQ (integer_type_node, TREE_TYPE (fntype));
 140
 141   /* Verify "void" args.  */
 142   tree argtypes = TYPE_ARG_TYPES (fntype);
 143   ASSERT_EQ (TREE_LIST, TREE_CODE (argtypes));
 144   ASSERT_EQ (void_type_node, TREE_VALUE (argtypes));
 145   ASSERT_EQ (NULL, TREE_CHAIN (argtypes));
 146 }
 147
 148 /* Verify creating a function declaration equivalent to the following
 149      float test_fndecl_float_intchar (int, char);
 150    C declaration.  */
 151
 152 static void
 153 test_fndecl_float_intchar ()
 154 {
 155   auto_vec <tree> param_types;
 156   param_types.safe_push (integer_type_node);
 157   param_types.safe_push (char_type_node);
 158   const char *name = "test_fndecl_float_intchar";
 159   tree fndecl = make_fndecl (float_type_node,
 160                              name,
 161                              param_types);
 162   ASSERT_TRUE (fndecl != NULL);
 163
 164   /* Verify name of decl.  */
 165   tree declname = DECL_NAME (fndecl);
 166   ASSERT_TRUE (declname != NULL);
 167   ASSERT_EQ (IDENTIFIER_NODE, TREE_CODE (declname));
 168   /* We expect it to use a *copy* of the string we passed in.  */
 169   const char *identifier_ptr = IDENTIFIER_POINTER (declname);
 170   ASSERT_NE (name, identifier_ptr);
 171   ASSERT_EQ (0, strcmp (name, identifier_ptr));
 172
 173   /* Verify type of fndecl.  */
 174   ASSERT_EQ (FUNCTION_DECL, TREE_CODE (fndecl));
 175   tree fntype = TREE_TYPE (fndecl);
 176   ASSERT_EQ (FUNCTION_TYPE, TREE_CODE (fntype));
 177
 178   /* Verify return type.  */
 179   ASSERT_EQ (float_type_node, TREE_TYPE (fntype));
 180
 181   /* Verify "(int, char)" args.  */
 182   tree arg0 = TYPE_ARG_TYPES (fntype);
 183   ASSERT_EQ (TREE_LIST, TREE_CODE (arg0));
 184   ASSERT_EQ (integer_type_node, TREE_VALUE (arg0));
 185   tree arg1 = TREE_CHAIN (arg0);
 186   ASSERT_TRUE (arg1 != NULL);
 187   ASSERT_EQ (TREE_LIST, TREE_CODE (arg1));
 188   ASSERT_EQ (char_type_node, TREE_VALUE (arg1));
 189   tree argterm = TREE_CHAIN (arg1);
 190   ASSERT_TRUE (argterm != NULL);
 191   ASSERT_EQ (TREE_LIST, TREE_CODE (argterm));
 192   ASSERT_EQ (void_type_node, TREE_VALUE (argterm));
 193   ASSERT_EQ (NULL, TREE_CHAIN (argterm));
 194 }
 195
 196 /* The test cases using these helper functions take a trivial function:
 197
 198      int test_fn (void) { return 42; }
 199
 200    and test various conversions done to it:
 201
 202    - gimplification
 203    - construction of the CFG
 204    - conversion to SSA form
 205    - expansion to RTL form
 206
 207    In avoid having one overlong test case, this is broken
 208    up into separate test cases for each stage, with helper functions
 209    to minimize code duplication.
 210
 211    Another approach would be to attempt to directly construct a function
 212    in the appropriate representation at each stage, though presumably
 213    that would exhibit different kinds of failure compared to this
 214    approach.  */
 215
 216 /* Construct this function:
 217    int test_fn (void) { return 42; }
 218    in generic tree form.  Return the fndecl.  */
 219
 220 static tree
 221 build_trivial_generic_function ()
 222 {
 223   auto_vec <tree> param_types;
 224   tree fndecl = make_fndecl (integer_type_node,
 225                              "test_fn",
 226                              param_types);
 227   ASSERT_TRUE (fndecl != NULL);
 228
 229   /* Populate the function.  */
 230   tree retval = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
 231                             NULL_TREE, integer_type_node);
 232   DECL_ARTIFICIAL (retval) = 1;
 233   DECL_IGNORED_P (retval) = 1;
 234   DECL_RESULT (fndecl) = retval;
 235
 236   /* Create a BIND_EXPR, and within it, a statement list.  */
 237   tree stmt_list = alloc_stmt_list ();
 238   tree_stmt_iterator stmt_iter = tsi_start (stmt_list);
 239   tree block = make_node (BLOCK);
 240   tree bind_expr
 241     = build3 (BIND_EXPR, void_type_node, NULL, stmt_list, block);
 242
 243   tree modify_retval = build2 (MODIFY_EXPR,
 244                                integer_type_node,
 245                                retval,
 246                                build_int_cst (integer_type_node, 42));
 247   tree return_stmt = build1 (RETURN_EXPR,
 248                              integer_type_node,
 249                              modify_retval);
 250   tsi_link_after (&stmt_iter, return_stmt, TSI_CONTINUE_LINKING);
 251
 252   DECL_INITIAL (fndecl) = block;
 253   BLOCK_SUPERCONTEXT (block) = fndecl;
 254
 255   /* how to add to function? the following appears to be how to
 256      set the body of a fndecl: */
 257   DECL_SAVED_TREE(fndecl) = bind_expr;
 258
 259   /* Ensure that locals appear in the debuginfo.  */
 260   BLOCK_VARS (block) = BIND_EXPR_VARS (bind_expr);
 261
 262   return fndecl;
 263 }
 264
 265 /* Construct this function:
 266      int test_fn (void) { return 42; }
 267    in "high gimple" form.  Return the fndecl.  */
 268
 269 static tree
 270 build_trivial_high_gimple_function ()
 271 {
 272   /* Construct a trivial function, and gimplify it: */
 273   tree fndecl = build_trivial_generic_function ();
 274   gimplify_function_tree (fndecl);
 275   return fndecl;
 276 }
 277
 278 /* Build a CFG for a function in gimple form.  */
 279
 280 static void
 281 build_cfg (tree fndecl)
 282 {
 283   function *fun = DECL_STRUCT_FUNCTION (fndecl);
 284   ASSERT_TRUE (fun != NULL);
 285   ASSERT_EQ (fndecl, fun->decl);
 286
 287   /* We first have to lower control flow; for our trivial test function
 288      this gives us:
 289          test_fn ()
 290          {
 291            D.56 = 42;
 292            goto <D.57>;
 293            <D.57>:
 294            return D.56;
 295          }
 296   */
 297   gimple_opt_pass *lower_cf_pass = make_pass_lower_cf (g);
 298   push_cfun (fun);
 299   lower_cf_pass->execute (fun);
 300   pop_cfun ();
 301   delete lower_cf_pass;
 302
 303   /* We can now convert to CFG form; for our trivial test function this
 304      gives us:
 305          test_fn ()
 306          {
 307            <bb 2>:
 308            D.56 = 42;
 309            return D.56;
 310          }
 311   */
 312   gimple_opt_pass *build_cfg_pass = make_pass_build_cfg (g);
 313   push_cfun (fun);
 314   build_cfg_pass->execute (fun);
 315   pop_cfun ();
 316   delete build_cfg_pass;
 317 }
 318
 319 /* Convert a gimple+CFG function to SSA form.  */
 320
 321 static void
 322 convert_to_ssa (tree fndecl)
 323 {
 324   function *fun = DECL_STRUCT_FUNCTION (fndecl);
 325   ASSERT_TRUE (fun != NULL);
 326   ASSERT_EQ (fndecl, fun->decl);
 327
 328   gimple_opt_pass *build_ssa_pass = make_pass_build_ssa (g);
 329   push_cfun (fun);
 330   build_ssa_pass->execute (fun);
 331   pop_cfun ();
 332   delete build_ssa_pass;
 333 }
 334
 335 /* Assuming we have a simple 3-block CFG like this:
 336      [ENTRY] -> [block2] -> [EXIT]
 337    get the "real" basic block (block 2).  */
 338
 339 static basic_block
 340 get_real_block (function *fun)
 341 {
 342   ASSERT_TRUE (fun->cfg != NULL);
 343   ASSERT_EQ (3, n_basic_blocks_for_fn (fun));
 344   basic_block bb2 = (*fun->cfg->x_basic_block_info)[2];
 345   ASSERT_TRUE (bb2 != NULL);
 346   return bb2;
 347 }
 348
 349 /* Verify that we have a simple 3-block CFG: the two "fake" ones, and
 350    a "real" one:
 351      [ENTRY] -> [block2] -> [EXIT].  */
 352
 353 static void
 354 verify_three_block_cfg (function *fun)
 355 {
 356   ASSERT_TRUE (fun->cfg != NULL);
 357   ASSERT_EQ (3, n_basic_blocks_for_fn (fun));
 358   ASSERT_EQ (2, n_edges_for_fn (fun));
 359
 360   /* The "fake" basic blocks.  */
 361   basic_block entry = ENTRY_BLOCK_PTR_FOR_FN (fun);
 362   ASSERT_TRUE (entry != NULL);
 363   ASSERT_EQ (ENTRY_BLOCK, entry->index);
 364
 365   basic_block exit = EXIT_BLOCK_PTR_FOR_FN (fun);
 366   ASSERT_TRUE (exit != NULL);
 367   ASSERT_EQ (EXIT_BLOCK, exit->index);
 368
 369   /* The "real" basic block.  */
 370   basic_block bb2 = get_real_block (fun);
 371   ASSERT_TRUE (bb2 != NULL);
 372   ASSERT_EQ (2, bb2->index);
 373
 374   /* Verify connectivity.  */
 375   ASSERT_EQ (NULL, entry->preds);
 376   ASSERT_EQ (1, entry->succs->length ());
 377
 378   edge from_entry_to_bb2 = (*entry->succs)[0];
 379   ASSERT_EQ (entry, from_entry_to_bb2->src);
 380   ASSERT_EQ (bb2, from_entry_to_bb2->dest);
 381
 382   ASSERT_EQ (1, bb2->preds->length ());
 383   ASSERT_EQ (from_entry_to_bb2, (*bb2->preds)[0]);
 384   ASSERT_EQ (1, bb2->succs->length ());
 385
 386   edge from_bb2_to_exit = (*bb2->succs)[0];
 387   ASSERT_EQ (bb2, from_bb2_to_exit->src);
 388   ASSERT_EQ (exit, from_bb2_to_exit->dest);
 389
 390   ASSERT_EQ (1, exit->preds->length ());
 391   ASSERT_EQ (from_bb2_to_exit, (*exit->preds)[0]);
 392   ASSERT_EQ (NULL, exit->succs);
 393 }
 394
 395 /* As above, but additionally verify the gimple statements are sane.  */
 396
 397 static void
 398 verify_three_block_gimple_cfg (function *fun)
 399 {
 400   verify_three_block_cfg (fun);
 401
 402   /* The "fake" basic blocks should be flagged as gimple, but with have no
 403      statements.  */
 404   basic_block entry = ENTRY_BLOCK_PTR_FOR_FN (fun);
 405   ASSERT_TRUE (entry != NULL);
 406   ASSERT_EQ (0, entry->flags & BB_RTL);
 407   ASSERT_EQ (NULL, bb_seq (entry));
 408
 409   basic_block exit = EXIT_BLOCK_PTR_FOR_FN (fun);
 410   ASSERT_TRUE (exit != NULL);
 411   ASSERT_EQ (0, entry->flags & BB_RTL);
 412   ASSERT_EQ (NULL, bb_seq (exit));
 413
 414   /* The "real" basic block should be flagged as gimple, and have one
 415      or more statements.  */
 416   basic_block bb2 = get_real_block (fun);
 417   ASSERT_TRUE (bb2 != NULL);
 418   ASSERT_EQ (0, entry->flags & BB_RTL);
 419   ASSERT_TRUE (bb_seq (bb2) != NULL);
 420 }
 421
 422 /* As above, but additionally verify the RTL insns are sane.  */
 423
 424 void
 425 verify_three_block_rtl_cfg (function *fun)
 426 {
 427   verify_three_block_cfg (fun);
 428
 429   /* The "fake" basic blocks should be flagged as RTL, but with no
 430      insns.  */
 431   basic_block entry = ENTRY_BLOCK_PTR_FOR_FN (fun);
 432   ASSERT_TRUE (entry != NULL);
 433   ASSERT_EQ (BB_RTL, entry->flags & BB_RTL);
 434   ASSERT_EQ (NULL, BB_HEAD (entry));
 435
 436   basic_block exit = EXIT_BLOCK_PTR_FOR_FN (fun);
 437   ASSERT_TRUE (exit != NULL);
 438   ASSERT_EQ (BB_RTL, exit->flags & BB_RTL);
 439   ASSERT_EQ (NULL, BB_HEAD (exit));
 440
 441   /* The "real" basic block should be flagged as RTL, and have one
 442      or more insns.  */
 443   basic_block bb2 = get_real_block (fun);
 444   ASSERT_TRUE (bb2 != NULL);
 445   ASSERT_EQ (BB_RTL, bb2->flags & BB_RTL);
 446   ASSERT_TRUE (BB_HEAD (bb2) != NULL);
 447 }
 448
 449 /* Test converting our trivial function:
 450      int test_fn (void) { return 42; }
 451    to gimple form.  */
 452
 453 static void
 454 test_gimplification ()
 455 {
 456   tree fndecl = build_trivial_generic_function ();
 457
 458   /* Convert to gimple: */
 459   gimplify_function_tree (fndecl);
 460
 461   /* Verify that we got gimple out of it.  */
 462
 463   /* The function is now in GIMPLE form but the CFG has not been
 464      built yet.  */
 465
 466   /* We should have a struct function for the decl.  */
 467   function *fun = DECL_STRUCT_FUNCTION (fndecl);
 468   ASSERT_TRUE (fun != NULL);
 469   ASSERT_EQ (fndecl, fun->decl);
 470
 471   /* We expect a GIMPLE_BIND, with two gimple statements within it:
 472        tmp = 42;
 473        return tmp;  */
 474
 475   gimple_seq seq_fn_body = gimple_body (fndecl);
 476   ASSERT_TRUE (seq_fn_body != NULL);
 477   gimple *bind_stmt = gimple_seq_first_stmt (seq_fn_body);
 478   ASSERT_EQ (GIMPLE_BIND, gimple_code (bind_stmt));
 479   ASSERT_EQ (NULL, bind_stmt->next);
 480
 481   gimple_seq seq_bind_body = gimple_bind_body (as_a <gbind *> (bind_stmt));
 482
 483   /* Verify that we have the 2 statements we expect.  */
 484   ASSERT_TRUE (seq_bind_body != NULL);
 485   gimple *stmt1 = gimple_seq_first_stmt (seq_bind_body);
 486   ASSERT_TRUE (stmt1 != NULL);
 487   ASSERT_EQ (GIMPLE_ASSIGN, gimple_code (stmt1));
 488   gimple *stmt2 = stmt1->next;
 489   ASSERT_TRUE (stmt2 != NULL);
 490   ASSERT_EQ (stmt1, stmt2->prev);
 491   ASSERT_EQ (GIMPLE_RETURN, gimple_code (stmt2));
 492 }
 493
 494 /* Test of building a CFG for a function in high gimple form.  */
 495
 496 static void
 497 test_building_cfg ()
 498 {
 499   /* Construct a trivial function, and gimplify it: */
 500   tree fndecl = build_trivial_high_gimple_function ();
 501   function *fun = DECL_STRUCT_FUNCTION (fndecl);
 502   ASSERT_TRUE (fun != NULL);
 503
 504   /* Build a CFG.  */
 505   build_cfg (fndecl);
 506
 507   /* The CFG-building code constructs a 4-block cfg (with
 508      ENTRY and EXIT):
 509        test_fn ()
 510        {
 511          <bb 2>:
 512          D.65 = 42;
 513
 514          <bb 3>:
 515          return D.65;
 516        }
 517      and then ought to merge blocks 2 and 3 in cleanup_tree_cfg.
 518
 519      Hence we should end up with a simple 3-block cfg, the two "fake" ones,
 520      and a "real" one:
 521        [ENTRY] -> [block2] -> [EXIT]
 522      with code like this:
 523          test_fn ()
 524          {
 525            <bb 2>:
 526            D.56 = 42;
 527            return D.56;
 528          }
 529   */
 530   verify_three_block_gimple_cfg (fun);
 531
 532   /* Verify the statements within the "real" block.  */
 533   basic_block bb2 = get_real_block (fun);
 534   gimple *stmt_a = gimple_seq_first_stmt (bb_seq (bb2));
 535   ASSERT_EQ (GIMPLE_ASSIGN, gimple_code (stmt_a));
 536   gimple *stmt_b = stmt_a->next;
 537   ASSERT_EQ (GIMPLE_RETURN, gimple_code (stmt_b));
 538   ASSERT_EQ (NULL, stmt_b->next);
 539 }
 540
 541 /* Test of conversion of gimple to SSA form.  */
 542
 543 static void
 544 test_conversion_to_ssa ()
 545 {
 546   /* As above, construct a trivial function, gimplify it, and build a CFG: */
 547   tree fndecl = build_trivial_high_gimple_function ();
 548   function *fun = DECL_STRUCT_FUNCTION (fndecl);
 549   ASSERT_TRUE (fun != NULL);
 550   build_cfg (fndecl);
 551
 552   convert_to_ssa (fndecl);
 553
 554   verify_three_block_gimple_cfg (fun);
 555
 556   /* For out trivial test function we should now have something like
 557      this:
 558        test_fn ()
 559        {
 560          <bb 2>:
 561          _1 = 42;
 562          return _1;
 563        }
 564   */
 565   basic_block bb2 = get_real_block (fun);
 566   gimple *stmt_a = gimple_seq_first_stmt (bb_seq (bb2));
 567   ASSERT_EQ (GIMPLE_ASSIGN, gimple_code (stmt_a));
 568
 569   gimple *stmt_b = stmt_a->next;
 570   ASSERT_EQ (GIMPLE_RETURN, gimple_code (stmt_b));
 571   ASSERT_EQ (NULL, stmt_b->next);
 572
 573   greturn *return_stmt = as_a <greturn *> (stmt_b);
 574   ASSERT_EQ (SSA_NAME, TREE_CODE (gimple_return_retval (return_stmt)));
 575 }
 576
 577 /* Test of expansion from gimple-ssa to RTL.  */
 578
 579 static void
 580 test_expansion_to_rtl ()
 581 {
 582   /* As above, construct a trivial function, gimplify it, build a CFG,
 583      and convert to SSA: */
 584   tree fndecl = build_trivial_high_gimple_function ();
 585   function *fun = DECL_STRUCT_FUNCTION (fndecl);
 586   ASSERT_TRUE (fun != NULL);
 587   build_cfg (fndecl);
 588   convert_to_ssa (fndecl);
 589
 590   /* We need a cgraph_node for it.  */
 591   cgraph_node::get_create (fndecl);
 592   /* Normally, cgraph_node::expand () would call
 593      init_function_start (and a bunch of other stuff),
 594      and invoke the expand pass, but it also runs
 595      all of the other passes.  So just do the minimum
 596      needed to get from gimple-SSA to RTL.  */
 597   rtl_opt_pass *expand_pass = make_pass_expand (g);
 598   push_cfun (fun);
 599   init_function_start (fndecl);
 600   expand_pass->execute (fun);
 601   pop_cfun ();
 602   delete expand_pass;
 603
 604   /* On x86_64, I get this:
 605        (note 3 1 2 2 [bb 2] NOTE_INSN_BASIC_BLOCK)
 606        (note 2 3 5 2 NOTE_INSN_FUNCTION_BEG)
 607        (insn 5 2 6 2 (set (reg:SI 87 [ D.59 ])
 608                           (const_int 42 [0x2a])) -1 (nil))
 609        (insn 6 5 10 2 (set (reg:SI 88 [ <retval> ])
 610                            (reg:SI 87 [ D.59 ])) -1 (nil))
 611        (insn 10 6 11 2 (set (reg/i:SI 0 ax)
 612                             (reg:SI 88 [ <retval> ])) -1 (nil))
 613        (insn 11 10 0 2 (use (reg/i:SI 0 ax)) -1 (nil))
 614
 615      On cr16-elf I get this:
 616        (note 4 1 2 2 [bb 2] NOTE_INSN_BASIC_BLOCK)
 617        (insn 2 4 3 2 (set (reg:SI 24)
 618             (reg/f:SI 16 virtual-incoming-args)) -1
 619           (nil))
 620        (note 3 2 6 2 NOTE_INSN_FUNCTION_BEG)
 621        (insn 6 3 7 2 (set (reg:HI 22 [ _1 ])
 622             (const_int 42 [0x2a])) -1
 623          (nil))
 624        (insn 7 6 11 2 (set (reg:HI 23 [ <retval> ])
 625            (reg:HI 22 [ _1 ])) -1
 626          (nil))
 627        (insn 11 7 12 2 (set (reg/i:HI 0 r0)
 628            (reg:HI 23 [ <retval> ])) -1
 629          (nil))
 630        (insn 12 11 0 2 (use (reg/i:HI 0 r0)) -1
 631          (nil)).  */
 632   verify_three_block_rtl_cfg (fun);
 633
 634   /* Verify as much of the RTL as we can whilst avoiding
 635      target-specific behavior.  */
 636   basic_block bb2 = get_real_block (fun);
 637
 638   /* Expect a NOTE_INSN_BASIC_BLOCK... */
 639   rtx_insn *insn = BB_HEAD (bb2);
 640   ASSERT_TRUE (insn != NULL);
 641   ASSERT_EQ (NOTE, insn->code);
 642   ASSERT_EQ (NOTE_INSN_BASIC_BLOCK, NOTE_KIND (insn));
 643   ASSERT_EQ (bb2, NOTE_BASIC_BLOCK (insn));
 644
 645   /* ...etc; any further checks are likely to over-specify things
 646      and run us into target dependencies.  */
 647
 648   /* Verify that print_rtl_function is sane.  */
 649   named_temp_file tmp_out (".rtl");
 650   FILE *outfile = fopen (tmp_out.get_filename (), "w");
 651   print_rtx_function (outfile, fun, true);
 652   fclose (outfile);
 653
 654   char *dump = read_file (SELFTEST_LOCATION, tmp_out.get_filename ());
 655   ASSERT_STR_CONTAINS (dump, "(function \"test_fn\"\n");
 656   ASSERT_STR_CONTAINS (dump, "  (insn-chain\n");
 657   ASSERT_STR_CONTAINS (dump, "    (block 2\n");
 658   ASSERT_STR_CONTAINS (dump, "      (edge-from entry (flags \"FALLTHRU\"))\n");
 659   ASSERT_STR_CONTAINS (dump, "      (cinsn "); /* ...etc.  */
 660   ASSERT_STR_CONTAINS (dump, "      (edge-to exit (flags \"FALLTHRU\"))\n");
 661   ASSERT_STR_CONTAINS (dump, "    ) ;; block 2\n");
 662   ASSERT_STR_CONTAINS (dump, "  ) ;; insn-chain\n");
 663   ASSERT_STR_CONTAINS (dump, "  (crtl\n");
 664   ASSERT_STR_CONTAINS (dump, "  ) ;; crtl\n");
 665   ASSERT_STR_CONTAINS (dump, ") ;; function \"test_fn\"\n");
 666
 667   free (dump);
 668 }
 669
 670 /* Run all of the selftests within this file.  */
 671
 672 void
 673 function_tests_c_tests ()
 674 {
 675   test_fndecl_int_void ();
 676   test_fndecl_float_intchar ();
 677   test_gimplification ();
 678   test_building_cfg ();
 679   test_conversion_to_ssa ();
 680   test_expansion_to_rtl ();
 681 }
 682
 683 } // namespace selftest
 684
 685 #endif /* #if CHECKING_P */