[thirdparty/gcc.git] / gcc / tsan.c

/* GCC instrumentation plugin for ThreadSanitizer.
   Copyright (C) 2011, 2012 Free Software Foundation, Inc.
   Contributed by Dmitry Vyukov <dvyukov@google.com>

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */


#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "intl.h"
#include "tm.h"
#include "basic-block.h"
#include "gimple.h"
#include "function.h"
#include "tree-flow.h"
#include "tree-pass.h"
#include "tree-iterator.h"
#include "langhooks.h"
#include "output.h"
#include "options.h"
#include "target.h"
#include "cgraph.h"
#include "diagnostic.h"

/* Number of instrumented memory accesses in the current function.  */

/* Builds the following decl
   void __tsan_read/writeX (void *addr);  */

static tree
get_memory_access_decl (bool is_write, unsigned size)
{
  enum built_in_function fcode;

  if (size <= 1)
    fcode = is_write ? BUILT_IN_TSAN_WRITE_1
		     : BUILT_IN_TSAN_READ_1;
  else if (size <= 3)
    fcode = is_write ? BUILT_IN_TSAN_WRITE_2
		     : BUILT_IN_TSAN_READ_2;
  else if (size <= 7)
    fcode = is_write ? BUILT_IN_TSAN_WRITE_4
		     : BUILT_IN_TSAN_READ_4;
  else if (size <= 15)
    fcode = is_write ? BUILT_IN_TSAN_WRITE_8
		     : BUILT_IN_TSAN_READ_8;
  else
    fcode = is_write ? BUILT_IN_TSAN_WRITE_16
		     : BUILT_IN_TSAN_READ_16;

  return builtin_decl_implicit (fcode);
}

/* Check as to whether EXPR refers to a store to vptr.  */

static tree
is_vptr_store (gimple stmt, tree expr, bool is_write)
{
  if (is_write == true
      && gimple_assign_single_p (stmt)
      && TREE_CODE (expr) == COMPONENT_REF)
    {
      tree field = TREE_OPERAND (expr, 1);
      if (TREE_CODE (field) == FIELD_DECL
	  && DECL_VIRTUAL_P (field))
	return gimple_assign_rhs1 (stmt);
    }
  return NULL;
}

/* Checks as to whether EXPR refers to constant var/field/param.
   Don't bother to instrument them.  */

static bool
is_load_of_const_p (tree expr, bool is_write)
{
  if (is_write)
    return false;
  if (TREE_CODE (expr) == COMPONENT_REF)
    expr = TREE_OPERAND (expr, 1);
  if (TREE_CODE (expr) == VAR_DECL
      || TREE_CODE (expr) == PARM_DECL
      || TREE_CODE (expr) == FIELD_DECL)
    {
      if (TREE_READONLY (expr))
	return true;
    }
  return false;
}

/* Instruments EXPR if needed. If any instrumentation is inserted,
 * return true. */

static bool
instrument_expr (gimple_stmt_iterator gsi, tree expr, bool is_write)
{
  enum tree_code tcode;
  tree base, rhs, expr_type, expr_ptr, builtin_decl;
  basic_block bb;
  HOST_WIDE_INT size;
  gimple stmt, g;
  location_t loc;

  base = get_base_address (expr);
  if (base == NULL_TREE
      || TREE_CODE (base) == SSA_NAME
      || TREE_CODE (base) == STRING_CST)
    return false;

  tcode = TREE_CODE (expr);

  /* Below are things we do not instrument
     (no possibility of races or not implemented yet).  */
  if (/* Compiler-emitted artificial variables.  */
      (DECL_P (expr) && DECL_ARTIFICIAL (expr))
      /* The var does not live in memory -> no possibility of races.  */
      || (tcode == VAR_DECL
	  && !TREE_ADDRESSABLE (expr)
	  && TREE_STATIC (expr) == 0)
      /* Not implemented.  */
      || TREE_CODE (TREE_TYPE (expr)) == RECORD_TYPE
      /* Not implemented.  */
      || tcode == CONSTRUCTOR
      /* Not implemented.  */
      || tcode == PARM_DECL
      /* Load of a const variable/parameter/field.  */
      || is_load_of_const_p (expr, is_write))
    return false;

  size = int_size_in_bytes (TREE_TYPE (expr));
  if (size == -1)
    return false;

  /* For now just avoid instrumenting bit field acceses.
     TODO: handle bit-fields as if touching the whole field.  */
  HOST_WIDE_INT bitsize, bitpos;
  tree offset;
  enum machine_mode mode;
  int volatilep = 0, unsignedp = 0;
  get_inner_reference (expr, &bitsize, &bitpos, &offset,
		       &mode, &unsignedp, &volatilep, false);
  if (bitpos % (size * BITS_PER_UNIT)
      || bitsize != size * BITS_PER_UNIT)
    return false;

  /* TODO: handle other case: ARRAY_RANGE_REF. */
  if (tcode != ARRAY_REF
      && tcode != VAR_DECL
      && tcode != COMPONENT_REF
      && tcode != INDIRECT_REF
      && tcode != MEM_REF)
    return false;

  stmt = gsi_stmt (gsi);
  loc = gimple_location (stmt);
  rhs = is_vptr_store (stmt, expr, is_write);
  gcc_checking_assert (rhs != NULL || is_gimple_addressable (expr));
  expr_ptr = build_fold_addr_expr (unshare_expr (expr));
  if (rhs == NULL)
    {
      expr_type = TREE_TYPE (expr);
      while (TREE_CODE (expr_type) == ARRAY_TYPE)
	expr_type = TREE_TYPE (expr_type);
      size = int_size_in_bytes (expr_type);
      g = gimple_build_call (get_memory_access_decl (is_write, size),
			     1, expr_ptr);
    }
  else
    {
      builtin_decl = builtin_decl_implicit (BUILT_IN_TSAN_VPTR_UPDATE);
      g = gimple_build_call (builtin_decl, 1, expr_ptr);
    }
  gimple_set_location (g, loc);
  /* Instrumentation for assignment of a function result
     must be inserted after the call.  Instrumentation for
     reads of function arguments must be inserted before the call.
     That's because the call can contain synchronization.  */
  if (is_gimple_call (stmt) && is_write)
    {
      /* If the call can throw, it must be the last stmt in
	 a basic block, so the instrumented stmts need to be
	 inserted in successor bbs. */
      if (is_ctrl_altering_stmt (stmt))
	{
	  edge e;

	  bb = gsi_bb (gsi);
	  e = find_fallthru_edge (bb->succs);
	  if (e)
	    gsi_insert_seq_on_edge_immediate (e, g);
	}
      else
	gsi_insert_after (&gsi, g, GSI_NEW_STMT);
    }
  else
    gsi_insert_before (&gsi, g, GSI_SAME_STMT);

  return true;
}

/* Instruments the gimple pointed to by GSI. Return
 * true if func entry/exit should be instrumented. */

static bool
instrument_gimple (gimple_stmt_iterator gsi)
{
  gimple stmt;
  tree rhs, lhs;
  bool instrumented = false;

  stmt = gsi_stmt (gsi);
  if (is_gimple_call (stmt)
      && (gimple_call_fndecl (stmt)
	  != builtin_decl_implicit (BUILT_IN_TSAN_INIT)))
    return true;
  else if (is_gimple_assign (stmt))
    {
      if (gimple_store_p (stmt))
	{
	  lhs = gimple_assign_lhs (stmt);
	  instrumented = instrument_expr (gsi, lhs, true);
	}
      if (gimple_assign_load_p (stmt))
	{
	  rhs = gimple_assign_rhs1 (stmt);
	  instrumented = instrument_expr (gsi, rhs, false);
	}
    }
  return instrumented;
}

/* Instruments all interesting memory accesses in the current function.
 * Return true if func entry/exit should be instrumented. */

static bool
instrument_memory_accesses (void)
{
  basic_block bb;
  gimple_stmt_iterator gsi;
  bool fentry_exit_instrument = false;

  FOR_EACH_BB (bb)
    for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
      fentry_exit_instrument |= instrument_gimple (gsi);
  return fentry_exit_instrument;
}

/* Instruments function entry.  */

static void
instrument_func_entry (void)
{
  basic_block succ_bb;
  gimple_stmt_iterator gsi;
  tree ret_addr, builtin_decl;
  gimple g;

  succ_bb = single_succ (ENTRY_BLOCK_PTR);
  gsi = gsi_after_labels (succ_bb);

  builtin_decl = builtin_decl_implicit (BUILT_IN_RETURN_ADDRESS);
  g = gimple_build_call (builtin_decl, 1, integer_zero_node);
  ret_addr = make_ssa_name (ptr_type_node, NULL);
  gimple_call_set_lhs (g, ret_addr);
  gimple_set_location (g, cfun->function_start_locus);
  gsi_insert_before (&gsi, g, GSI_SAME_STMT);

  builtin_decl =  builtin_decl_implicit (BUILT_IN_TSAN_FUNC_ENTRY);
  g = gimple_build_call (builtin_decl, 1, ret_addr);
  gimple_set_location (g, cfun->function_start_locus);
  gsi_insert_before (&gsi, g, GSI_SAME_STMT);
}

/* Instruments function exits.  */

static void
instrument_func_exit (void)
{
  location_t loc;
  basic_block exit_bb;
  gimple_stmt_iterator gsi;
  gimple stmt, g;
  tree builtin_decl;
  edge e;
  edge_iterator ei;

  /* Find all function exits.  */
  exit_bb = EXIT_BLOCK_PTR;
  FOR_EACH_EDGE (e, ei, exit_bb->preds)
    {
      gsi = gsi_last_bb (e->src);
      stmt = gsi_stmt (gsi);
      gcc_assert (gimple_code (stmt) == GIMPLE_RETURN);
      loc = gimple_location (stmt);
      builtin_decl = builtin_decl_implicit (BUILT_IN_TSAN_FUNC_EXIT);
      g = gimple_build_call (builtin_decl, 0);
      gimple_set_location (g, loc);
      gsi_insert_before (&gsi, g, GSI_SAME_STMT);
    }
}

/* ThreadSanitizer instrumentation pass.  */

static unsigned
tsan_pass (void)
{
  if (instrument_memory_accesses ())
    {
      instrument_func_entry ();
      instrument_func_exit ();
    }
  return 0;
}

/* The pass's gate.  */

static bool
tsan_gate (void)
{
  return flag_tsan != 0
	 && builtin_decl_implicit_p (BUILT_IN_TSAN_INIT);
}

/* Inserts __tsan_init () into the list of CTORs.  */

void
tsan_finish_file (void)
{
  tree ctor_statements;
  tree init_decl;

  ctor_statements = NULL_TREE;
  init_decl = builtin_decl_implicit (BUILT_IN_TSAN_INIT);
  append_to_statement_list (build_call_expr (init_decl, 0),
			    &ctor_statements);
  cgraph_build_static_cdtor ('I', ctor_statements,
			     MAX_RESERVED_INIT_PRIORITY - 1);
}

/* The pass descriptor.  */

struct gimple_opt_pass pass_tsan =
{
 {
  GIMPLE_PASS,
  "tsan",				/* name  */
  OPTGROUP_NONE,			/* optinfo_flags */
  tsan_gate,				/* gate  */
  tsan_pass,				/* execute  */
  NULL,					/* sub  */
  NULL,					/* next  */
  0,					/* static_pass_number  */
  TV_NONE,				/* tv_id  */
  PROP_ssa | PROP_cfg,			/* properties_required  */
  0,					/* properties_provided  */
  0,					/* properties_destroyed  */
  0,					/* todo_flags_start  */
  TODO_verify_all | TODO_update_ssa
  | TODO_update_address_taken		/* todo_flags_finish  */
 }
};

static bool
tsan_gate_O0 (void)
{
  return flag_tsan != 0 && !optimize
	 && builtin_decl_implicit_p (BUILT_IN_TSAN_INIT);
}

struct gimple_opt_pass pass_tsan_O0 =
{
 {
  GIMPLE_PASS,
  "tsan0",				/* name  */
  OPTGROUP_NONE,			/* optinfo_flags */
  tsan_gate_O0,				/* gate  */
  tsan_pass,				/* execute  */
  NULL,					/* sub  */
  NULL,					/* next  */
  0,					/* static_pass_number  */
  TV_NONE,				/* tv_id  */
  PROP_ssa | PROP_cfg,			/* properties_required  */
  0,					/* properties_provided  */
  0,					/* properties_destroyed  */
  0,					/* todo_flags_start  */
  TODO_verify_all | TODO_update_ssa
  | TODO_update_address_taken		/* todo_flags_finish  */
 }
};
Commit	Line	Data
32b4b7f5 DV	1	/* GCC instrumentation plugin for ThreadSanitizer.
	2	Copyright (C) 2011, 2012 Free Software Foundation, Inc.
	3	Contributed by Dmitry Vyukov <dvyukov@google.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
	22	#include "config.h"
	23	#include "system.h"
	24	#include "coretypes.h"
	25	#include "tree.h"
	26	#include "intl.h"
	27	#include "tm.h"
	28	#include "basic-block.h"
	29	#include "gimple.h"
	30	#include "function.h"
	31	#include "tree-flow.h"
	32	#include "tree-pass.h"
	33	#include "tree-iterator.h"
	34	#include "langhooks.h"
	35	#include "output.h"
	36	#include "options.h"
	37	#include "target.h"
	38	#include "cgraph.h"
	39	#include "diagnostic.h"
	40
	41	/* Number of instrumented memory accesses in the current function. */
	42
	43	/* Builds the following decl
	44	void __tsan_read/writeX (void addr); /
	45
	46	static tree
	47	get_memory_access_decl (bool is_write, unsigned size)
	48	{
	49	enum built_in_function fcode;
	50
	51	if (size <= 1)
	52	fcode = is_write ? BUILT_IN_TSAN_WRITE_1
	53	: BUILT_IN_TSAN_READ_1;
	54	else if (size <= 3)
	55	fcode = is_write ? BUILT_IN_TSAN_WRITE_2
	56	: BUILT_IN_TSAN_READ_2;
	57	else if (size <= 7)
	58	fcode = is_write ? BUILT_IN_TSAN_WRITE_4
	59	: BUILT_IN_TSAN_READ_4;
	60	else if (size <= 15)
	61	fcode = is_write ? BUILT_IN_TSAN_WRITE_8
	62	: BUILT_IN_TSAN_READ_8;
	63	else
	64	fcode = is_write ? BUILT_IN_TSAN_WRITE_16
65	: BUILT_IN_TSAN_READ_16;
66
67	return builtin_decl_implicit (fcode);
68	}
69
70	/* Check as to whether EXPR refers to a store to vptr. */
71
72	static tree
73	is_vptr_store (gimple stmt, tree expr, bool is_write)
74	{
75	if (is_write == true
76	&& gimple_assign_single_p (stmt)
77	&& TREE_CODE (expr) == COMPONENT_REF)
78	{
79	tree field = TREE_OPERAND (expr, 1);
80	if (TREE_CODE (field) == FIELD_DECL
81	&& DECL_VIRTUAL_P (field))
82	return gimple_assign_rhs1 (stmt);
83	}
84	return NULL;
85	}
86
87	/* Checks as to whether EXPR refers to constant var/field/param.
88	Don't bother to instrument them. */
89
90	static bool
91	is_load_of_const_p (tree expr, bool is_write)
92	{
93	if (is_write)
94	return false;
95	if (TREE_CODE (expr) == COMPONENT_REF)
96	expr = TREE_OPERAND (expr, 1);
97	if (TREE_CODE (expr) == VAR_DECL
98	\|\| TREE_CODE (expr) == PARM_DECL
99	\|\| TREE_CODE (expr) == FIELD_DECL)
100	{
101	if (TREE_READONLY (expr))
102	return true;
103	}
104	return false;
105	}
106
107	/* Instruments EXPR if needed. If any instrumentation is inserted,
108	* return true. */
109
110	static bool
111	instrument_expr (gimple_stmt_iterator gsi, tree expr, bool is_write)
112	{
113	enum tree_code tcode;
114	tree base, rhs, expr_type, expr_ptr, builtin_decl;
115	basic_block bb;
116	HOST_WIDE_INT size;
117	gimple stmt, g;
118	location_t loc;
119
120	base = get_base_address (expr);
121	if (base == NULL_TREE
122	\|\| TREE_CODE (base) == SSA_NAME
123	\|\| TREE_CODE (base) == STRING_CST)
124	return false;
125
126	tcode = TREE_CODE (expr);
127
128	/* Below are things we do not instrument
129	(no possibility of races or not implemented yet). */
130	if (/* Compiler-emitted artificial variables. */
131	(DECL_P (expr) && DECL_ARTIFICIAL (expr))
132	/* The var does not live in memory -> no possibility of races. */
133	\|\| (tcode == VAR_DECL
134	&& !TREE_ADDRESSABLE (expr)
135	&& TREE_STATIC (expr) == 0)
136	/* Not implemented. */
137	\|\| TREE_CODE (TREE_TYPE (expr)) == RECORD_TYPE
138	/* Not implemented. */
139	\|\| tcode == CONSTRUCTOR
140	/* Not implemented. */
141	\|\| tcode == PARM_DECL
142	/* Load of a const variable/parameter/field. */
143	\|\| is_load_of_const_p (expr, is_write))
144	return false;
145
146	size = int_size_in_bytes (TREE_TYPE (expr));
147	if (size == -1)
148	return false;
149
150	/* For now just avoid instrumenting bit field acceses.
151	TODO: handle bit-fields as if touching the whole field. */
152	HOST_WIDE_INT bitsize, bitpos;
153	tree offset;
154	enum machine_mode mode;
155	int volatilep = 0, unsignedp = 0;
156	get_inner_reference (expr, &bitsize, &bitpos, &offset,
157	&mode, &unsignedp, &volatilep, false);
158	if (bitpos % (size * BITS_PER_UNIT)
159	\|\| bitsize != size * BITS_PER_UNIT)
160	return false;
161
162	/* TODO: handle other case: ARRAY_RANGE_REF. */
163	if (tcode != ARRAY_REF
164	&& tcode != VAR_DECL
165	&& tcode != COMPONENT_REF
166	&& tcode != INDIRECT_REF
167	&& tcode != MEM_REF)
168	return false;
169
170	stmt = gsi_stmt (gsi);
171	loc = gimple_location (stmt);
172	rhs = is_vptr_store (stmt, expr, is_write);
173	gcc_checking_assert (rhs != NULL \|\| is_gimple_addressable (expr));
174	expr_ptr = build_fold_addr_expr (unshare_expr (expr));
175	if (rhs == NULL)
176	{
177	expr_type = TREE_TYPE (expr);
178	while (TREE_CODE (expr_type) == ARRAY_TYPE)
179	expr_type = TREE_TYPE (expr_type);
180	size = int_size_in_bytes (expr_type);
181	g = gimple_build_call (get_memory_access_decl (is_write, size),
182	1, expr_ptr);
183	}
184	else
185	{
186	builtin_decl = builtin_decl_implicit (BUILT_IN_TSAN_VPTR_UPDATE);
187	g = gimple_build_call (builtin_decl, 1, expr_ptr);
188	}
189	gimple_set_location (g, loc);
190	/* Instrumentation for assignment of a function result
191	must be inserted after the call. Instrumentation for
192	reads of function arguments must be inserted before the call.
193	That's because the call can contain synchronization. */
194	if (is_gimple_call (stmt) && is_write)
195	{
196	/* If the call can throw, it must be the last stmt in
197	a basic block, so the instrumented stmts need to be
198	inserted in successor bbs. */
199	if (is_ctrl_altering_stmt (stmt))
200	{
201	edge e;
202
203	bb = gsi_bb (gsi);
204	e = find_fallthru_edge (bb->succs);
205	if (e)
206	gsi_insert_seq_on_edge_immediate (e, g);
207	}
208	else
209	gsi_insert_after (&gsi, g, GSI_NEW_STMT);
210	}
211	else
212	gsi_insert_before (&gsi, g, GSI_SAME_STMT);
213
214	return true;
215	}
216
217	/* Instruments the gimple pointed to by GSI. Return
218	* true if func entry/exit should be instrumented. */
219
220	static bool
221	instrument_gimple (gimple_stmt_iterator gsi)
222	{
223	gimple stmt;
224	tree rhs, lhs;
225	bool instrumented = false;
226
227	stmt = gsi_stmt (gsi);
228	if (is_gimple_call (stmt)
229	&& (gimple_call_fndecl (stmt)
230	!= builtin_decl_implicit (BUILT_IN_TSAN_INIT)))
231	return true;
232	else if (is_gimple_assign (stmt))
233	{
234	if (gimple_store_p (stmt))
235	{
236	lhs = gimple_assign_lhs (stmt);
237	instrumented = instrument_expr (gsi, lhs, true);
238	}
239	if (gimple_assign_load_p (stmt))
240	{
241	rhs = gimple_assign_rhs1 (stmt);
242	instrumented = instrument_expr (gsi, rhs, false);
243	}
244	}
245	return instrumented;
246	}
247
248	/* Instruments all interesting memory accesses in the current function.
249	* Return true if func entry/exit should be instrumented. */
250
251	static bool
252	instrument_memory_accesses (void)
253	{
254	basic_block bb;
255	gimple_stmt_iterator gsi;
256	bool fentry_exit_instrument = false;
257
258	FOR_EACH_BB (bb)
259	for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
260	fentry_exit_instrument \|= instrument_gimple (gsi);
261	return fentry_exit_instrument;
262	}
263
264	/* Instruments function entry. */
265
266	static void
267	instrument_func_entry (void)
268	{
269	basic_block succ_bb;
270	gimple_stmt_iterator gsi;
271	tree ret_addr, builtin_decl;
272	gimple g;
273
274	succ_bb = single_succ (ENTRY_BLOCK_PTR);
275	gsi = gsi_after_labels (succ_bb);
276
277	builtin_decl = builtin_decl_implicit (BUILT_IN_RETURN_ADDRESS);
278	g = gimple_build_call (builtin_decl, 1, integer_zero_node);
279	ret_addr = make_ssa_name (ptr_type_node, NULL);
280	gimple_call_set_lhs (g, ret_addr);
281	gimple_set_location (g, cfun->function_start_locus);
282	gsi_insert_before (&gsi, g, GSI_SAME_STMT);
283
284	builtin_decl = builtin_decl_implicit (BUILT_IN_TSAN_FUNC_ENTRY);
285	g = gimple_build_call (builtin_decl, 1, ret_addr);
286	gimple_set_location (g, cfun->function_start_locus);
287	gsi_insert_before (&gsi, g, GSI_SAME_STMT);
288	}
289
290	/* Instruments function exits. */
291
292	static void
293	instrument_func_exit (void)
294	{
295	location_t loc;
296	basic_block exit_bb;
297	gimple_stmt_iterator gsi;
298	gimple stmt, g;
299	tree builtin_decl;
300	edge e;
301	edge_iterator ei;
302
303	/* Find all function exits. */
304	exit_bb = EXIT_BLOCK_PTR;
305	FOR_EACH_EDGE (e, ei, exit_bb->preds)
306	{
307	gsi = gsi_last_bb (e->src);
308	stmt = gsi_stmt (gsi);
309	gcc_assert (gimple_code (stmt) == GIMPLE_RETURN);
310	loc = gimple_location (stmt);
311	builtin_decl = builtin_decl_implicit (BUILT_IN_TSAN_FUNC_EXIT);
312	g = gimple_build_call (builtin_decl, 0);
313	gimple_set_location (g, loc);
314	gsi_insert_before (&gsi, g, GSI_SAME_STMT);
315	}
316	}
317
318	/* ThreadSanitizer instrumentation pass. */
319
320	static unsigned
321	tsan_pass (void)
322	{
323	if (instrument_memory_accesses ())
324	{
325	instrument_func_entry ();
326	instrument_func_exit ();
327	}
328	return 0;
329	}
330
331	/* The pass's gate. */
332
333	static bool
334	tsan_gate (void)
335	{
336	return flag_tsan != 0
337	&& builtin_decl_implicit_p (BUILT_IN_TSAN_INIT);
338	}
339
340	/* Inserts __tsan_init () into the list of CTORs. */
341
342	void
343	tsan_finish_file (void)
344	{
345	tree ctor_statements;
346	tree init_decl;
347
348	ctor_statements = NULL_TREE;
349	init_decl = builtin_decl_implicit (BUILT_IN_TSAN_INIT);
350	append_to_statement_list (build_call_expr (init_decl, 0),
351	&ctor_statements);
352	cgraph_build_static_cdtor ('I', ctor_statements,
353	MAX_RESERVED_INIT_PRIORITY - 1);
354	}
355
356	/* The pass descriptor. */
357
358	struct gimple_opt_pass pass_tsan =
359	{
360	{
361	GIMPLE_PASS,
362	"tsan", /* name */
363	OPTGROUP_NONE, /* optinfo_flags */
364	tsan_gate, /* gate */
365	tsan_pass, /* execute */
366	NULL, /* sub */
367	NULL, /* next */
368	0, /* static_pass_number */
369	TV_NONE, /* tv_id */
370	PROP_ssa \| PROP_cfg, /* properties_required */
371	0, /* properties_provided */
372	0, /* properties_destroyed */
373	0, /* todo_flags_start */
374	TODO_verify_all \| TODO_update_ssa
375	\| TODO_update_address_taken /* todo_flags_finish */
376	}
377	};
378
379	static bool
380	tsan_gate_O0 (void)
381	{
382	return flag_tsan != 0 && !optimize
383	&& builtin_decl_implicit_p (BUILT_IN_TSAN_INIT);
384	}
385
386	struct gimple_opt_pass pass_tsan_O0 =
387	{
388	{
389	GIMPLE_PASS,
390	"tsan0", /* name */
391	OPTGROUP_NONE, /* optinfo_flags */
392	tsan_gate_O0, /* gate */
393	tsan_pass, /* execute */
394	NULL, /* sub */
395	NULL, /* next */
396	0, /* static_pass_number */
397	TV_NONE, /* tv_id */
398	PROP_ssa \| PROP_cfg, /* properties_required */
399	0, /* properties_provided */
400	0, /* properties_destroyed */
401	0, /* todo_flags_start */
402	TODO_verify_all \| TODO_update_ssa
403	\| TODO_update_address_taken /* todo_flags_finish */
404	}
405	};