kbuild: remove EXTRA_*FLAGS support

Commit f77bf01425 ("kbuild: introduce ccflags-y, asflags-y and
ldflags-y") deprecated these in 2007. The migration should have been
completed by now.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>

Documentation/dev-tools/checkpatch.rst

@@ -342,24 +342,6 @@ API usage
 
     See: https://www.kernel.org/doc/html/latest/RCU/whatisRCU.html#full-list-of-rcu-apis
 
-  **DEPRECATED_VARIABLE**
-    EXTRA_{A,C,CPP,LD}FLAGS are deprecated and should be replaced by the new
-    flags added via commit f77bf01425b1 ("kbuild: introduce ccflags-y,
-    asflags-y and ldflags-y").
-
-    The following conversion scheme maybe used::
-
-      EXTRA_AFLAGS    ->  asflags-y
-      EXTRA_CFLAGS    ->  ccflags-y
-      EXTRA_CPPFLAGS  ->  cppflags-y
-      EXTRA_LDFLAGS   ->  ldflags-y
-
-    See:
-
-      1. https://lore.kernel.org/lkml/20070930191054.GA15876@uranus.ravnborg.org/
-      2. https://lore.kernel.org/lkml/1313384834-24433-12-git-send-email-lacombar@gmail.com/
-      3. https://www.kernel.org/doc/html/latest/kbuild/makefiles.html#compilation-flags
-
   **DEVICE_ATTR_FUNCTIONS**
     The function names used in DEVICE_ATTR is unusual.
     Typically, the store and show functions are used with <attr>_store and

Documentation/kbuild/makefiles.rst

@@ -318,9 +318,6 @@ ccflags-y, asflags-y and ldflags-y
   These three flags apply only to the kbuild makefile in which they
   are assigned. They are used for all the normal cc, as and ld
   invocations happening during a recursive build.
-  Note: Flags with the same behaviour were previously named:
-  EXTRA_CFLAGS, EXTRA_AFLAGS and EXTRA_LDFLAGS.
-  They are still supported but their usage is deprecated.
 
   ccflags-y specifies options for compiling with $(CC).
 

scripts/Makefile.build

@@ -20,10 +20,6 @@ always-m :=
 targets :=
 subdir-y :=
 subdir-m :=
-EXTRA_AFLAGS   :=
-EXTRA_CFLAGS   :=
-EXTRA_CPPFLAGS :=
-EXTRA_LDFLAGS  :=
 asflags-y  :=
 ccflags-y  :=
 rustflags-y :=

scripts/Makefile.lib

@@ -1,9 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
-# Backward compatibility
-asflags-y  += $(EXTRA_AFLAGS)
-ccflags-y  += $(EXTRA_CFLAGS)
-cppflags-y += $(EXTRA_CPPFLAGS)
-ldflags-y  += $(EXTRA_LDFLAGS)
 
 # flags that take effect in current and sub directories
 KBUILD_AFLAGS += $(subdir-asflags-y)

scripts/checkpatch.pl

@@ -3689,20 +3689,6 @@ sub process {
 			}
 		}
 
-		if (($realfile =~ /Makefile.*/ || $realfile =~ /Kbuild.*/) &&
-		    ($line =~ /\+(EXTRA_[A-Z]+FLAGS).*/)) {
-			my $flag = $1;
-			my $replacement = {
-				'EXTRA_AFLAGS' =>   'asflags-y',
-				'EXTRA_CFLAGS' =>   'ccflags-y',
-				'EXTRA_CPPFLAGS' => 'cppflags-y',
-				'EXTRA_LDFLAGS' =>  'ldflags-y',
-			};
-
-			WARN("DEPRECATED_VARIABLE",
-			     "Use of $flag is deprecated, please use \`$replacement->{$flag} instead.\n" . $herecurr) if ($replacement->{$flag});
-		}
-
 # check for DT compatible documentation
 		if (defined $root &&
 			(($realfile =~ /\.dtsi?$/ && $line =~ /^\+\s*compatible\s*=\s*\"/) ||