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, 71 insertions, 6 deletions

diff --git a/contrib/gcc/doc/invoke.texi b/contrib/gcc/doc/invoke.texi
index ce6f071909a4..51ac30f0dfa5 100644
--- a/contrib/gcc/doc/invoke.texi
+++ b/contrib/gcc/doc/invoke.texi
@@ -214,7 +214,8 @@ in the following sections.
 -Wimport  -Wno-import  -Winit-self  -Winline @gol
 -Wno-int-to-pointer-cast @gol
 -Wno-invalid-offsetof  -Winvalid-pch @gol
--Wlarger-than-@var{len}  -Wunsafe-loop-optimizations  -Wlong-long @gol
+-Wlarger-than-@var{len}  -Wframe-larger-than-@var{len} @gol
+-Wunsafe-loop-optimizations  -Wlong-long @gol
 -Wmain  -Wmissing-braces  -Wmissing-field-initializers @gol
 -Wmissing-format-attribute  -Wmissing-include-dirs @gol
 -Wmissing-noreturn @gol
@@ -758,6 +759,8 @@ See S/390 and zSeries Options.
 -fnon-call-exceptions  -funwind-tables @gol
 -fasynchronous-unwind-tables @gol
 -finhibit-size-directive  -finstrument-functions @gol
+-finstrument-functions-exclude-function-list=@var{sym},@var{sym},@dots{} @gol
+-finstrument-functions-exclude-file-list=@var{file},@var{file},@dots{} @gol
 -fno-common  -fno-ident @gol
 -fpcc-struct-return  -fpic  -fPIC -fpie -fPIE @gol
 -fno-jump-tables @gol
@@ -2505,14 +2508,40 @@ It warns about code which might break the strict aliasing rules that the
 compiler is using for optimization.  The warning does not catch all
 cases, but does attempt to catch the more common pitfalls.  It is
 included in @option{-Wall}.
+It is equivalent to -Wstrict-aliasing=3
 
-@item -Wstrict-aliasing=2
-@opindex Wstrict-aliasing=2
+@item -Wstrict-aliasing=n
+@opindex Wstrict-aliasing=n
 This option is only active when @option{-fstrict-aliasing} is active.
 It warns about code which might break the strict aliasing rules that the
-compiler is using for optimization.  This warning catches more cases than
-@option{-Wstrict-aliasing}, but it will also give a warning for some ambiguous
-cases that are safe.
+compiler is using for optimization.
+Higher levels correspond to higher accuracy (fewer false positives).
+Higher levels also correspond to more effort, similar to the way -O works.
+@option{-Wstrict-aliasing} is equivalent to @option{-Wstrict-aliasing=n},
+with n=3.
+
+Level 1: Most aggressive, quick, least accurate.
+Possibly useful when higher levels
+do not warn but -fstrict-aliasing still breaks the code, as it has very few 
+false negatives.  However, it has many false positives.
+Warns for all pointer conversions between possibly incompatible types, 
+even if never dereferenced.  Runs in the frontend only.
+
+Level 2: Aggressive, quick, not too precise.
+May still have many false positives (not as many as level 1 though),
+and few false negatives (but possibly more than level 1).
+Unlike level 1, it only warns when an address is taken.  Warns about
+incomplete types.  Runs in the frontend only.
+
+Level 3 (default for @option{-Wstrict-aliasing}): 
+Should have very few false positives and few false 
+negatives.  Slightly slower than levels 1 or 2 when optimization is enabled.
+Takes care of the common punn+dereference pattern in the frontend:
+@code{*(int*)&some_float}.
+If optimization is enabled, it also runs in the backend, where it deals 
+with multiple statement cases using flow-sensitive points-to information.
+Only warns when the converted pointer is dereferenced.
+Does not warn about incomplete types.
 
 @item -Wstrict-overflow
 @item -Wstrict-overflow=@var{n}
@@ -2828,6 +2857,10 @@ global variable or whenever a built-in function is shadowed.
 @opindex Wlarger-than
 Warn whenever an object of larger than @var{len} bytes is defined.
 
+@item -Wframe-larger-than-@var{len}
+@opindex Wframe-larger-than
+Warn whenever the frame size of a function is larger than @var{len} bytes.
+
 @item -Wunsafe-loop-optimizations
 @opindex Wunsafe-loop-optimizations
 Warn if the loop cannot be optimized because the compiler could not
@@ -13355,6 +13388,37 @@ interrupt routines, and any functions from which the profiling functions
 cannot safely be called (perhaps signal handlers, if the profiling
 routines generate output or allocate memory).
 
+@item -finstrument-functions-exclude-file-list=@var{file},@var{file},@dots{}
+@opindex finstrument-functions-exclude-file-list
+
+Set the list of functions that are excluded from instrumentation (see
+the description of @code{-finstrument-functions}).  If the file that
+contains a function definition matches with one of @var{file}, then
+that function is not instrumented.  The match is done on substrings:
+if the @var{file} parameter is a substring of the file name, it is
+considered to be a match.
+
+For example,
+@code{-finstrument-functions-exclude-file-list=/bits/stl,include/sys}
+will exclude any inline function defined in files whose pathnames
+contain @code{/bits/stl} or @code{include/sys}.
+
+If, for some reason, you want to include letter @code{','} in one of
+@var{sym}, write @code{'\,'}. For example,
+@code{-finstrument-functions-exclude-file-list='\,\,tmp'}
+(note the single quote surrounding the option).
+
+@item -finstrument-functions-exclude-function-list=@var{sym},@var{sym},@dots{}
+@opindex finstrument-functions-exclude-function-list
+
+This is similar to @code{-finstrument-functions-exclude-file-list},
+but this option sets the list of function names to be excluded from
+instrumentation.  The function name to be matched is its user-visible
+name, such as @code{vector<int> blah(const vector<int> &)}, not the
+internal mangled name (e.g., @code{_Z4blahRSt6vectorIiSaIiEE}).  The
+match is done on substrings: if the @var{sym} parameter is a substring
+of the function name, it is considered to be a match.
+
 @item -fstack-check
 @opindex fstack-check
 Generate code to verify that you do not go beyond the boundary of the
@@ -13932,3 +13996,4 @@ exist, because otherwise they won't get converted.
 
 @xref{Protoize Caveats}, for more information on how to use
 @code{protoize} successfully.
+