--- a/ChangeLog	Mon May 16 08:05:06 2016 -0700
+++ b/ChangeLog	Tue May 17 09:08:02 2016 -0700
@@ -1,3 +1,11 @@
+2016-05-17  Paul Eggert  <eggert@cs.ucla.edu>
+
+	manywarnings: update for GCC 6.1
+	* m4/manywarnings.m4 (gl_MANYWARN_ALL_GCC):
+	Add GCC 6.1 options that apply to C.
+	* build-aux/gcc-warning.spec: Add GCC 6.1 options that
+	do not apply to C, are obsolescent, etc.
+
 2016-05-12  Paul Eggert  <eggert@cs.ucla.edu>
 
 	glob: size_t overflow checks

--- a/build-aux/gcc-warning.spec	Mon May 16 08:05:06 2016 -0700
+++ b/build-aux/gcc-warning.spec	Tue May 17 09:08:02 2016 -0700
@@ -31,13 +31,16 @@
 -Wdelete-non-virtual-dtor		c++
 -Weffc++				c++
 -Werror-implicit-function-declaration	deprecated
+-Wfloat-conversion			FIXME maybe? borderline.  some will want this
 -Wfloat-equal				FIXME maybe? borderline.  some will want this
 -Wformat				covered by -Wformat=2
 -Wformat=				gcc --help=warnings artifact
+-Wframe-larger-than=<number>		FIXME: choose something sane?
 -Wfunction-elimination			fortran
 -Wimplicit-interface			fortran
 -Wimplicit-procedure			fortran
 -Winherited-variadic-ctor		c++
+-Winteger-division			fortran
 -Wintrinsic-shadow			fortran
 -Wintrinsics-std			fortran
 -Winvalid-offsetof			c++ and objc++
@@ -46,14 +49,23 @@
 -Wline-truncation			fortran
 -Wliteral-suffix			c++ and objc++
 -Wlong-long				obsolescent
+-Wlto-type-mismatch			c++ and objc++
+-Wmissing-format-attribute		obsolescent
+-Wmissing-noreturn			obsolescent
+-Wmultiple-inheritance			c++ and objc++
+-Wnamespaces				c++
 -Wnoexcept				c++
 -Wnon-template-friend			c++
 -Wnon-virtual-dtor			c++
+-Wnormalized				covered by -Wnormalized=
 -Wnormalized=<none|id|nfc|nfkc>		handled specially by gl_MANYWARN_ALL_GCC
 -Wold-style-cast			c++ and objc++
 -Woverloaded-virtual			c++
+-Woverride-init-side-effects		c++ and objc++
 -Wpadded				FIXME maybe?  warns about "stabil" member in /usr/include/bits/timex.h
 -Wpedantic				FIXME: too strict?
+-Wplacement-new				c++
+-Wplacement-new=			c++
 -Wpmf-conversions			c++ and objc++
 -Wproperty-assign-default		objc++
 -Wprotocol				objc++
@@ -64,6 +76,8 @@
 -Wreorder				c++ and objc++
 -Wselector				objc and objc++
 -Wshadow-ivar				objc
+-Wshift-overflow			covered by -Wshift-overflow=2
+-Wshift-overflow=			gcc --help=warnings artifact
 -Wsign-compare				FIXME maybe? borderline.  some will want this
 -Wsign-conversion			FIXME maybe? borderline.  some will want this
 -Wsign-promo				c++ and objc++
@@ -73,21 +87,28 @@
 -Wstrict-null-sentinel			c++ and objc++
 -Wstrict-overflow=			FIXME: choose something sane?
 -Wstrict-selector-match			objc and objc++
+-Wsubobject-linkage			c++ and objc++
 -Wsuggest-override			c++ and objc++
 -Wsurprising				fortran
 -Wswitch-enum				FIXME maybe? borderline.  some will want this
 -Wsynth					deprecated
 -Wtabs					fortran
 -Wtarget-lifetime			fortran
+-Wtemplates				c++ and objc++
+-Wterminate				c++ and objc++
 -Wtraditional				obsolescent
 -Wtraditional-conversion		obsolescent
 -Wundeclared-selector			objc and objc++
 -Wundef					FIXME maybe? too many false positives
 -Wunderflow				fortran
+-Wunreachable-code			obsolescent no-op
 -Wunsuffixed-float-constants		triggers warning in gnulib's timespec.h
+-Wunused-const-variable			covered by -Wunusec-const-variable=2
+-Wunused-const-variable=		gcc --help=warnings artifact
 -Wunused-dummy-argument			fortran
 -Wuse-without-only			fortran
 -Wuseless-cast				c++ and objc++
+-Wvirtual-inheritance			c++
 -Wvirtual-move-assign			c++
 -Wzero-as-null-pointer-constant		c++ and objc++
 -Wzerotrip				fortran

--- a/m4/manywarnings.m4	Mon May 16 08:05:06 2016 -0700
+++ b/m4/manywarnings.m4	Tue May 17 09:08:02 2016 -0700
@@ -1,4 +1,4 @@
-# manywarnings.m4 serial 7
+# manywarnings.m4 serial 8
 dnl Copyright (C) 2008-2016 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -129,6 +129,7 @@
     -Wdiscarded-qualifiers \
     -Wdiv-by-zero \
     -Wdouble-promotion \
+    -Wduplicated-cond \
     -Wempty-body \
     -Wendif-labels \
     -Wenum-compare \
@@ -140,7 +141,10 @@
     -Wformat-signedness \
     -Wformat-y2k \
     -Wformat-zero-length \
+    -Wframe-address \
     -Wfree-nonheap-object \
+    -Whsa \
+    -Wignored-attributes \
     -Wignored-qualifiers \
     -Wimplicit \
     -Wimplicit-function-declaration \
@@ -158,6 +162,7 @@
     -Wmain \
     -Wmaybe-uninitialized \
     -Wmemset-transposed-args \
+    -Wmisleading-indentation \
     -Wmissing-braces \
     -Wmissing-declarations \
     -Wmissing-field-initializers \
@@ -168,6 +173,8 @@
     -Wnarrowing \
     -Wnested-externs \
     -Wnonnull \
+    -Wnonnull-compare \
+    -Wnull-dereference \
     -Wodr \
     -Wold-style-declaration \
     -Wold-style-definition \
@@ -184,10 +191,12 @@
     -Wpragmas \
     -Wreturn-local-addr \
     -Wreturn-type \
+    -Wscalar-storage-order \
     -Wsequence-point \
     -Wshadow \
     -Wshift-count-negative \
     -Wshift-count-overflow \
+    -Wshift-negative-value \
     -Wsizeof-array-argument \
     -Wsizeof-pointer-memaccess \
     -Wstack-protector \
@@ -205,6 +214,7 @@
     -Wswitch-default \
     -Wsync-nand \
     -Wsystem-headers \
+    -Wtautological-compare \
     -Wtrampolines \
     -Wtrigraphs \
     -Wtype-limits \
@@ -237,6 +247,8 @@
   # them here so that the above 'comm' command doesn't report a false match.
   gl_manywarn_set="$gl_manywarn_set -Warray-bounds=2"
   gl_manywarn_set="$gl_manywarn_set -Wnormalized=nfc"
+  gl_manywarn_set="$gl_manywarn_set -Wshift-overflow=2"
+  gl_manywarn_set="$gl_manywarn_set -Wunused-const-variable=2"
 
   # These are needed for older GCC versions.
   if test -n "$GCC"; then