gcc: Bring updates from Google's enhanced gcc-4.2.1.

Google released and enhanced version of gcc-4.2.1 plus their local
patches for Android[1].

The patches are owned by Google and the license hasn't been changed
from  the original GPLv2. We are only bringing a subset of the
available patches that may be helpful in FreeBSD. Changes specific
to android are not included.

From the README.google file[1].

Patches applied to google_vendor_src_branch/gcc/gcc-4.2.1:

gcc/Makefile.in
gcc/c-common.c
gcc/c-common.h
gcc/c-opts.c
gcc/c-typeck.c
gcc/cp/typeck.c
gcc/doc/invoke.texi
gcc/flags.h
gcc/opts.c
gcc/tree-flow.h
gcc/tree-ssa-alias-warnings.c
gcc/tree-ssa-alias.c

 Backport of -Wstrict-aliasing from mainline.
  Silvius Rus <rus@google.com>

gcc/coverage.c:
  Patch coverage_checksum_string for PR 25351.
  Seongbae Park <spark@google.com>
  Not yet submitted to FSF.

gcc/c-opts.c
gcc/c-ppoutput.c
gcc/c.opt
gcc/doc/cppopts.texi
libcpp/Makefile.in
libcpp/directives-only.c
libcpp/directives.c
libcpp/files.c
libcpp/include/cpplib.h
libcpp/init.c
libcpp/internal.h
libcpp/macro.c
  Support for -fdirectives-only.
  Ollie Wild <aaw@google.com>.
  Submitted to FSF but not yet approved.

libstdc++-v3/include/ext/hashtable.h
  http://b/742065
  http://b/629994
  Reduce min size of hashtable for hash_map, hash_set from 53 to 5

libstdc++-v3/include/ext/hashtable.h
  http://b/629994
  Do not iterate over buckets if hashtable is empty.

gcc/common.opt
gcc/doc/invoke.texi
gcc/flags.h
gcc/gimplify.c
gcc/opts.c
  Add Saito's patch for -finstrument-functions-exclude-* options.

gcc/common.opt
gcc/doc/invoke.texi
gcc/final.c
gcc/flags.h
gcc/opts.c
gcc/testsuite/gcc.dg/Wframe-larger-than.c
  Add a new flag -Wframe-larger-than- which enables a new warning
  when a frame size of a function is larger than specified.
  This patch hasn't been integrated into gcc mainline yet.

gcc/tree-vrp.c
  Add a hack to avoid using ivopts information for pointers starting
  at constant values.

Reference:

[1]
https://android.googlesource.com/toolchain/gcc/+/master/gcc-4.2.1/

Obtained from:	Google Inc.
MFC after:	3 weeks

1 files changed, 127 insertions, 0 deletions

diff --git a/contrib/gcc/opts.c b/contrib/gcc/opts.c
index 1ded3c711b74..87f8984a1a9b 100644
--- a/contrib/gcc/opts.c
+++ b/contrib/gcc/opts.c
@@ -59,6 +59,11 @@ bool extra_warnings;
 bool warn_larger_than;
 HOST_WIDE_INT larger_than_size;
 
+/* True to warn about any function whose frame size is larger
+ * than N bytes. */
+bool warn_frame_larger_than;
+HOST_WIDE_INT frame_larger_than_size;
+
 /* Nonzero means warn about constructs which might not be
    strict-aliasing safe.  */
 int warn_strict_aliasing;
@@ -358,6 +363,15 @@ static bool flag_unroll_loops_set, flag_tracer_set;
 static bool flag_value_profile_transformations_set;
 static bool flag_peel_loops_set, flag_branch_probabilities_set;
 
+/* Functions excluded from profiling.  */
+
+typedef char *char_p; /* For DEF_VEC_P.  */
+DEF_VEC_P(char_p);
+DEF_VEC_ALLOC_P(char_p,heap);
+
+static VEC(char_p,heap) *flag_instrument_functions_exclude_functions;
+static VEC(char_p,heap) *flag_instrument_functions_exclude_files;
+
 /* Input file names.  */
 const char **in_fnames;
 unsigned num_in_fnames;
@@ -604,6 +618,87 @@ add_input_filename (const char *filename)
   in_fnames[num_in_fnames - 1] = filename;
 }
 
+/* Add functions or file names to a vector of names to exclude from
+   instrumentation.  */
+
+static void
+add_instrument_functions_exclude_list (VEC(char_p,heap) **pvec,
+				       const char* arg)
+{
+  char *tmp;
+  char *r;
+  char *w;
+  char *token_start;
+
+  /* We never free this string.  */
+  tmp = xstrdup (arg);
+
+  r = tmp;
+  w = tmp;
+  token_start = tmp;
+
+  while (*r != '\0')
+    {
+      if (*r == ',')
+	{
+	  *w++ = '\0';
+	  ++r;
+	  VEC_safe_push (char_p, heap, *pvec, token_start);
+	  token_start = w;
+	}
+      if (*r == '\\' && r[1] == ',')
+	{
+	  *w++ = ',';
+	  r += 2;
+	}
+      else
+	*w++ = *r++;
+    }
+  if (*token_start != '\0')
+    VEC_safe_push (char_p, heap, *pvec, token_start);
+}
+
+/* Return whether we should exclude FNDECL from instrumentation.  */
+
+bool
+flag_instrument_functions_exclude_p (tree fndecl)
+{
+  if (VEC_length (char_p, flag_instrument_functions_exclude_functions) > 0)
+    {
+      const char *name;
+      int i;
+      char *s;
+
+      name = lang_hooks.decl_printable_name (fndecl, 0);
+      for (i = 0;
+	   VEC_iterate (char_p, flag_instrument_functions_exclude_functions,
+			i, s);
+	   ++i)
+	{
+	  if (strstr (name, s) != NULL)
+	    return true;
+	}
+    }
+
+  if (VEC_length (char_p, flag_instrument_functions_exclude_files) > 0)
+    {
+      const char *name;
+      int i;
+      char *s;
+
+      name = DECL_SOURCE_FILE (fndecl);
+      for (i = 0;
+	   VEC_iterate (char_p, flag_instrument_functions_exclude_files, i, s);
+	   ++i)
+	{
+	  if (strstr (name, s) != NULL)
+	    return true;
+	}
+    }
+
+  return false;
+}
+
 /* Decode and handle the vector of command line options.  LANG_MASK
    contains has a single bit set representing the current
    language.  */
@@ -979,7 +1074,15 @@ common_handle_option (size_t scode, const char *arg, int value,
       warn_larger_than = value != -1;
       break;
 
+    case OPT_Wframe_larger_than_:
+      frame_larger_than_size = value;
+      warn_frame_larger_than = value != -1;
+      break;
+
     case OPT_Wstrict_aliasing:
+      set_warn_strict_aliasing (value);
+      break;
+
     case OPT_Wstrict_aliasing_:
       warn_strict_aliasing = value;
       break;
@@ -1086,6 +1189,16 @@ common_handle_option (size_t scode, const char *arg, int value,
       set_param_value ("max-inline-insns-auto", value / 2);
       break;
 
+    case OPT_finstrument_functions_exclude_function_list_:
+      add_instrument_functions_exclude_list
+	(&flag_instrument_functions_exclude_functions, arg);
+      break;
+
+    case OPT_finstrument_functions_exclude_file_list_:
+      add_instrument_functions_exclude_list
+	(&flag_instrument_functions_exclude_files, arg);
+      break;
+
     case OPT_fmessage_length_:
       pp_set_line_maximum_length (global_dc->printer, value);
       break;
@@ -1348,6 +1461,20 @@ set_Wunused (int setting)
   warn_unused_value = setting;
 }
 
+/* Used to set the level of strict aliasing warnings, 
+   when no level is specified (i.e., when -Wstrict-aliasing, and not
+   -Wstrict-aliasing=level was given).
+   ONOFF is assumed to take value 1 when -Wstrict-aliasing is specified,
+   and 0 otherwise.  After calling this function, wstrict_aliasing will be
+   set to the default value of -Wstrict_aliasing=level, currently 3.  */
+void
+set_warn_strict_aliasing (int onoff)
+{
+  gcc_assert (onoff == 0 || onoff == 1);
+  if (onoff != 0)
+    warn_strict_aliasing = 3;
+}
+
 /* The following routines are useful in setting all the flags that
    -ffast-math and -fno-fast-math imply.  */
 void