gcc: stop adding -fno-common for checking builds

Originally added in r0-44646-g204250d2fcd084 and r0-44627-gfd350d241fecf6 whic
moved -fno-common from all builds to just checking builds.

Since r10-4867-g6271dd984d7f92, GCC defaults to -fno-common. There's no need
to pass it specially for checking builds.

We could keep it for older bootstrap compilers with checking but I don't see
much value in that, it was already just a bonus before.

gcc/ChangeLog:
	* Makefile.in (NOCOMMON_FLAG): Delete.
	(GCC_WARN_CFLAGS): Drop NOCOMMON_FLAG.
	(GCC_WARN_CXXFLAGS): Drop NOCOMMON_FLAG.
	* configure.ac: Ditto.
	* configure: Regenerate.

gcc/d/ChangeLog:
	* Make-lang.in (WARN_DFLAGS): Drop NOCOMMON_FLAG.

4 files changed, 5 insertions, 16 deletions

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index f4bb4a8..4fc86ed 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -185,10 +185,6 @@ C_LOOSE_WARN = @c_loose_warn@
 STRICT_WARN = @strict_warn@
 C_STRICT_WARN = @c_strict_warn@
 
-# This is set by --enable-checking.  The idea is to catch forgotten
-# "extern" tags in header files.
-NOCOMMON_FLAG = @nocommon_flag@
-
 NOEXCEPTION_FLAGS = @noexception_flags@
 
 ALIASING_FLAGS = @aliasing_flags@
@@ -215,8 +211,8 @@ VALGRIND_DRIVER_DEFINES = @valgrind_path_defines@
 .-warn = $(STRICT_WARN)
 build-warn = $(STRICT_WARN)
 rtl-ssa-warn = $(STRICT_WARN)
-GCC_WARN_CFLAGS = $(LOOSE_WARN) $(C_LOOSE_WARN) $($(@D)-warn) $(if $(filter-out $(STRICT_WARN),$($(@D)-warn)),,$(C_STRICT_WARN)) $(NOCOMMON_FLAG) $($@-warn)
-GCC_WARN_CXXFLAGS = $(LOOSE_WARN) $($(@D)-warn) $(NOCOMMON_FLAG) $($@-warn)
+GCC_WARN_CFLAGS = $(LOOSE_WARN) $(C_LOOSE_WARN) $($(@D)-warn) $(if $(filter-out $(STRICT_WARN),$($(@D)-warn)),,$(C_STRICT_WARN)) $($@-warn)
+GCC_WARN_CXXFLAGS = $(LOOSE_WARN) $($(@D)-warn) $($@-warn)
 
 # 1 2 3 ... 9999
 one_to_9999_0:=1 2 3 4 5 6 7 8 9
diff --git a/gcc/configure b/gcc/configure
index 4faae0f..01acca7 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -862,7 +862,6 @@ valgrind_command
 valgrind_path_defines
 valgrind_path
 TREECHECKING
-nocommon_flag
 noexception_flags
 warn_cxxflags
 warn_cflags
@@ -7605,17 +7604,14 @@ do
 done
 IFS="$ac_save_IFS"
 
-nocommon_flag=""
 if test x$ac_checking != x ; then
 
 $as_echo "#define CHECKING_P 1" >>confdefs.h
 
-  nocommon_flag=-fno-common
 else
   $as_echo "#define CHECKING_P 0" >>confdefs.h
 
 fi
-
 if test x$ac_extra_checking != x ; then
 
 $as_echo "#define ENABLE_EXTRA_CHECKING 1" >>confdefs.h
@@ -21410,7 +21406,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 21413 "configure"
+#line 21409 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -21516,7 +21512,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 21519 "configure"
+#line 21515 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 3da1eaa..3f20c10 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -697,16 +697,13 @@ do
 done
 IFS="$ac_save_IFS"
 
-nocommon_flag=""
 if test x$ac_checking != x ; then
   AC_DEFINE(CHECKING_P, 1,
 [Define to 0/1 if you want more run-time sanity checks.  This one gets a grab
 bag of miscellaneous but relatively cheap checks.])
-  nocommon_flag=-fno-common
 else
   AC_DEFINE(CHECKING_P, 0)
 fi
-AC_SUBST(nocommon_flag)
 if test x$ac_extra_checking != x ; then
   AC_DEFINE(ENABLE_EXTRA_CHECKING, 1,
 [Define to 0/1 if you want extra run-time checking that might affect code
diff --git a/gcc/d/Make-lang.in b/gcc/d/Make-lang.in
index eaea6e0..077668f 100644
--- a/gcc/d/Make-lang.in
+++ b/gcc/d/Make-lang.in
@@ -55,7 +55,7 @@ CHECKING_DFLAGS = -frelease
 else
 CHECKING_DFLAGS =
 endif
-WARN_DFLAGS = -Wall -Wdeprecated $(NOCOMMON_FLAG)
+WARN_DFLAGS = -Wall -Wdeprecated
 
 # D front-end doesn't use exceptions, but it does require RTTI.
 NOEXCEPTION_DFLAGS = $(filter-out -fno-rtti, $(NOEXCEPTION_FLAGS))