builtins.def (DEF_SANITIZER_BUILTIN): Define tsan builtins.

2012-11-22  Dmitry Vyukov  <dvyukov@google.com>
	    Wei Mi  <wmi@google.com>

	* builtins.def (DEF_SANITIZER_BUILTIN): Define tsan builtins. 
	* sanitizer.def: Ditto. 
	* Makefile.in (tsan.o): Add tsan.o target. 
	(BUILTINS_DEF): Add sanitizer.def.
	* passes.c (init_optimization_passes): Add tsan passes.
	* tree-pass.h (register_pass_info): Ditto.
	* toplev.c (compile_file): Ditto. 
	* doc/invoke.texi: Document tsan related options.
	* gcc.c (LINK_COMMAND_SPEC): Add LIBTSAN_SPEC in link command if
	-fsanitize=thread.
	* tsan.c: New file about tsan.
	* tsan.h: Ditto.
	* common.opt: Add -fsanitize=thread.


Co-Authored-By: Wei Mi <wmi@google.com>

From-SVN: r193736

12 files changed, 542 insertions, 3 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index cd3717f..9bd49a8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,20 @@
+2012-11-22  Dmitry Vyukov  <dvyukov@google.com>
+	    Wei Mi  <wmi@google.com>
+
+	* builtins.def (DEF_SANITIZER_BUILTIN): Define tsan builtins. 
+	* sanitizer.def: Ditto. 
+	* Makefile.in (tsan.o): Add tsan.o target. 
+	(BUILTINS_DEF): Add sanitizer.def.
+	* passes.c (init_optimization_passes): Add tsan passes.
+	* tree-pass.h (register_pass_info): Ditto.
+	* toplev.c (compile_file): Ditto. 
+	* doc/invoke.texi: Document tsan related options.
+	* gcc.c (LINK_COMMAND_SPEC): Add LIBTSAN_SPEC in link command if
+	-fsanitize=thread.
+	* tsan.c: New file about tsan.
+	* tsan.h: Ditto.
+	* common.opt: Add -fsanitize=thread.
+
 2012-11-22  Uros Bizjak  <ubizjak@gmail.com>
 
 	* doc/md.texi (RTL Templates Transformation): Use @pxref for
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 88b29ea..7ac7b25 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -863,7 +863,7 @@ RTL_ERROR_H = rtl-error.h $(RTL_H) $(DIAGNOSTIC_CORE_H)
 READ_MD_H = $(OBSTACK_H) $(HASHTAB_H) read-md.h
 PARAMS_H = params.h params.def
 BUILTINS_DEF = builtins.def sync-builtins.def omp-builtins.def \
-	gtm-builtins.def
+	gtm-builtins.def sanitizer.def
 INTERNAL_FN_DEF = internal-fn.def
 INTERNAL_FN_H = internal-fn.h $(INTERNAL_FN_DEF)
 TREE_H = coretypes.h tree.h all-tree.def tree.def c-family/c-common.def \
@@ -1365,6 +1365,7 @@ OBJS = \
 	trans-mem.o \
 	tree-affine.o \
 	asan.o \
+	tsan.o \
 	tree-call-cdce.o \
 	tree-cfg.o \
 	tree-cfgcleanup.o \
@@ -2228,6 +2229,12 @@ asan.o : asan.c asan.h $(CONFIG_H) $(SYSTEM_H) $(GIMPLE_H) \
    output.h coretypes.h $(GIMPLE_PRETTY_PRINT_H) \
    tree-iterator.h $(TREE_FLOW_H) $(TREE_PASS_H) \
    $(TARGET_H) $(EXPR_H) $(OPTABS_H) $(TM_P_H)
+tsan.o : $(CONFIG_H) $(SYSTEM_H) $(TREE_H) $(TREE_INLINE_H) \
+   $(GIMPLE_H) $(DIAGNOSTIC_H) langhooks.h \
+   $(TM_H) coretypes.h $(TREE_DUMP_H) $(TREE_PASS_H) $(CGRAPH_H) $(GGC_H) \
+   $(BASIC_BLOCK_H) $(FLAGS_H) $(FUNCTION_H) \
+   $(TM_P_H) $(TREE_FLOW_H) $(DIAGNOSTIC_CORE_H) $(GIMPLE_H) tree-iterator.h \
+   intl.h cfghooks.h output.h options.h c-family/c-common.h tsan.h
 tree-ssa-tail-merge.o: tree-ssa-tail-merge.c \
    $(SYSTEM_H) $(CONFIG_H) coretypes.h $(TM_H) $(BITMAP_H) \
    $(FLAGS_H) $(TM_P_H) $(BASIC_BLOCK_H) \
@@ -2689,7 +2696,8 @@ toplev.o : toplev.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H) \
    $(CGRAPH_H) $(COVERAGE_H) alloc-pool.h $(GGC_H) \
    $(OPTS_H) params.def tree-mudflap.h $(TREE_PASS_H) $(GIMPLE_H) \
    tree-ssa-alias.h $(PLUGIN_H) realmpfr.h tree-diagnostic.h \
-   $(TREE_PRETTY_PRINT_H) opts-diagnostic.h $(COMMON_TARGET_H)
+   $(TREE_PRETTY_PRINT_H) opts-diagnostic.h $(COMMON_TARGET_H) \
+   tsan.h
 
 hwint.o : hwint.c $(CONFIG_H) $(SYSTEM_H) $(DIAGNOSTIC_CORE_H)
 
@@ -3740,6 +3748,7 @@ GTFILES = $(CPP_ID_DATA_H) $(srcdir)/input.h $(srcdir)/coretypes.h \
   $(srcdir)/target-globals.h \
   $(srcdir)/ipa-inline.h \
   $(srcdir)/asan.c \
+  $(srcdir)/tsan.c \
   @all_gtfiles@
 
 # Compute the list of GT header files from the corresponding C sources,
diff --git a/gcc/builtins.def b/gcc/builtins.def
index d3dad11..bfafa53 100644
--- a/gcc/builtins.def
+++ b/gcc/builtins.def
@@ -149,6 +149,15 @@ along with GCC; see the file COPYING3.  If not see
   DEF_BUILTIN (ENUM, "__builtin_" NAME, BUILT_IN_NORMAL, TYPE, TYPE,    \
 	       true, true, true, ATTRS, false, flag_tm)
 
+/* Builtin used by the implementation of libsanitizer. These
+   functions are mapped to the actual implementation of the 
+   libtsan library. */
+#undef DEF_SANITIZER_BUILTIN
+#define DEF_SANITIZER_BUILTIN(ENUM, NAME, TYPE, ATTRS) \
+  DEF_BUILTIN (ENUM, "__builtin_" NAME, BUILT_IN_NORMAL, TYPE, TYPE,    \
+	       true, true, true, ATTRS, true, \
+	       flag_tsan)
+
 /* Define an attribute list for math functions that are normally
    "impure" because some of them may write into global memory for
    `errno'.  If !flag_errno_math they are instead "const".  */
@@ -825,3 +834,7 @@ DEF_GCC_BUILTIN (BUILT_IN_LINE, "LINE", BT_FN_INT, ATTR_NOTHROW_LEAF_LIST)
 
 /* GTM builtins. */
 #include "gtm-builtins.def"
+
+/* Sanitizer builtins. */
+#include "sanitizer.def"
+
diff --git a/gcc/common.opt b/gcc/common.opt
index d3ad5ab..5cf16b6 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -844,6 +844,10 @@ fsanitize=address
 Common Report Var(flag_asan)
 Enable AddressSanitizer, a memory error detector
 
+fsanitize=thread
+Common Report Var(flag_tsan)
+Enable ThreadSanitizer, a data race detector
+
 fasynchronous-unwind-tables
 Common Report Var(flag_asynchronous_unwind_tables) Optimization
 Generate unwind tables that are exact at each instruction boundary
@@ -2519,6 +2523,9 @@ Driver
 static-libasan
 Driver
 
+static-libtsan
+Driver
+
 symbolic
 Driver
 
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index a1c59f0..9c2629c 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -453,7 +453,8 @@ Objective-C and Objective-C++ Dialects}.
 @xref{Link Options,,Options for Linking}.
 @gccoptlist{@var{object-file-name}  -l@var{library} @gol
 -nostartfiles  -nodefaultlibs  -nostdlib -pie -rdynamic @gol
--s  -static -static-libgcc -static-libasan -static-libstdc++ @gol
+-s  -static -static-libgcc -static-libstdc++ @gol
+-static-libasan -static-libtsan @gol
 -shared -shared-libgcc  -symbolic @gol
 -T @var{script}  -Wl,@var{option}  -Xlinker @var{option} @gol
 -u @var{symbol}}
@@ -6862,6 +6863,12 @@ Memory access instructions will be instrumented to detect
 out-of-bounds and use-after-free bugs. So far only heap bugs will be detected.
 See @uref{http://code.google.com/p/address-sanitizer/} for more details.
 
+@item -fsanitize=thread
+Enable ThreadSanitizer, a fast data race detector.
+Memory access instructions will be instrumented to detect
+data race bugs. 
+See @uref{http://code.google.com/p/data-race-test/wiki/ThreadSanitizer} for more details.
+
 @item -fmudflap -fmudflapth -fmudflapir
 @opindex fmudflap
 @opindex fmudflapth
@@ -9947,6 +9954,15 @@ option is not used, then this links against the shared version of
 driver to link @file{libasan} statically, without necessarily linking
 other libraries statically.
 
+@item -static-libtsan
+When the @option{-fsanitize=thread} option is used to link a program,
+the GCC driver automatically links against @option{libtsan}.  If
+@file{libtsan} is available as a shared library, and the @option{-static}
+option is not used, then this links against the shared version of
+@file{libtsan}.  The @option{-static-libtsan} option directs the GCC
+driver to link @file{libtsan} statically, without necessarily linking
+other libraries statically.
+
 @item -static-libstdc++
 When the @command{g++} program is used to link a C++ program, it
 normally automatically links against @option{libstdc++}.  If
diff --git a/gcc/gcc.c b/gcc/gcc.c
index ce5ab61..13e93e5 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -560,6 +560,15 @@ proper position among the other output files.  */
 #endif
 #endif
 
+#ifndef LIBTSAN_SPEC
+#ifdef HAVE_LD_STATIC_DYNAMIC
+#define LIBTSAN_SPEC "%{static-libtsan:" LD_STATIC_OPTION \
+		     "} -ltsan %{static-libtsan:" LD_DYNAMIC_OPTION "}"
+#else
+#define LIBTSAN_SPEC "-ltsan"
+#endif
+#endif
+
 /* config.h can define LIBGCC_SPEC to override how and when libgcc.a is
    included.  */
 #ifndef LIBGCC_SPEC
@@ -704,6 +713,7 @@ proper position among the other output files.  */
     %(mflib) " STACK_SPLIT_SPEC "\
     %{fprofile-arcs|fprofile-generate*|coverage:-lgcov}\
     %{fsanitize=address:" LIBASAN_SPEC "%{static:%ecannot specify -static with -fsanitize=address}}\
+    %{fsanitize=thread:" LIBTSAN_SPEC "}\
     %{!nostdlib:%{!nodefaultlibs:%(link_ssp) %(link_gcc_c_sequence)}}\
     %{!nostdlib:%{!nostartfiles:%E}} %{T*} }}}}}}"
 #endif
diff --git a/gcc/passes.c b/gcc/passes.c
index 909f49e..ee21a9a 100644
--- a/gcc/passes.c
+++ b/gcc/passes.c
@@ -1450,6 +1450,7 @@ init_optimization_passes (void)
       NEXT_PASS (pass_pre);
       NEXT_PASS (pass_sink_code);
       NEXT_PASS (pass_asan);
+      NEXT_PASS (pass_tsan);
       NEXT_PASS (pass_tree_loop);
 	{
 	  struct opt_pass **p = &pass_tree_loop.pass.sub;
@@ -1556,6 +1557,7 @@ init_optimization_passes (void)
     }
   NEXT_PASS (pass_lower_complex_O0);
   NEXT_PASS (pass_asan_O0);
+  NEXT_PASS (pass_tsan_O0);
   NEXT_PASS (pass_cleanup_eh);
   NEXT_PASS (pass_lower_resx);
   NEXT_PASS (pass_nrv);
diff --git a/gcc/sanitizer.def b/gcc/sanitizer.def
new file mode 100644
index 0000000..28518f3
--- /dev/null
+++ b/gcc/sanitizer.def
@@ -0,0 +1,28 @@
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_INIT, "__tsan_init", 
+		      BT_FN_VOID, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_FUNC_ENTRY, "__tsan_func_entry",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_FUNC_EXIT, "__tsan_func_exit",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_VPTR_UPDATE, "__tsan_vptr_update",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_READ_1, "__tsan_read1",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_READ_2, "__tsan_read2",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_READ_4, "__tsan_read4",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_READ_8, "__tsan_read8",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_READ_16, "__tsan_read16",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_WRITE_1, "__tsan_write1",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_WRITE_2, "__tsan_write2",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_WRITE_4, "__tsan_write4",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_WRITE_8, "__tsan_write8",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_WRITE_16, "__tsan_write16",
+		      BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST)
diff --git a/gcc/toplev.c b/gcc/toplev.c
index fcdbd1a..d9d1127 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -73,6 +73,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "alloc-pool.h"
 #include "tree-mudflap.h"
 #include "asan.h"
+#include "tsan.h"
 #include "gimple.h"
 #include "tree-ssa-alias.h"
 #include "plugin.h"
@@ -575,6 +576,9 @@ compile_file (void)
       if (flag_asan)
         asan_finish_file ();
 
+      if (flag_tsan)
+	tsan_finish_file ();
+
       output_shared_constant_pool ();
       output_object_blocks ();
       finish_tm_clone_pairs ();
diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
index 929d510..7581cf3 100644
--- a/gcc/tree-pass.h
+++ b/gcc/tree-pass.h
@@ -261,6 +261,8 @@ extern struct gimple_opt_pass pass_mudflap_1;
 extern struct gimple_opt_pass pass_mudflap_2;
 extern struct gimple_opt_pass pass_asan;
 extern struct gimple_opt_pass pass_asan_O0;
+extern struct gimple_opt_pass pass_tsan;
+extern struct gimple_opt_pass pass_tsan_O0;
 extern struct gimple_opt_pass pass_lower_cf;
 extern struct gimple_opt_pass pass_refactor_eh;
 extern struct gimple_opt_pass pass_lower_eh;
diff --git a/gcc/tsan.c b/gcc/tsan.c
new file mode 100644
index 0000000..8660b87
--- /dev/null
+++ b/gcc/tsan.c
@@ -0,0 +1,405 @@
+/* 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  */
+ }
+};
diff --git a/gcc/tsan.h b/gcc/tsan.h
new file mode 100644
index 0000000..cafc980
--- /dev/null
+++ b/gcc/tsan.h
@@ -0,0 +1,26 @@
+/* ThreadSanitizer, a data race detector.
+   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/>.  */
+
+#ifndef TREE_TSAN
+#define TREE_TSAN
+
+extern void tsan_finish_file (void);
+
+#endif /* TREE_TSAN */