kbuild: replace genhdr-y with generated-y

Originally, generated-y and genhdr-y had different meaning, like
follows:

- generated-y: generated headers (other than asm-generic wrappers)
- header-y   : headers to be exported
- genhdr-y   : generated headers to be exported (generated-y + header-y)

Since commit fcc8487d47 ("uapi: export all headers under uapi
directories"), headers under UAPI directories are all exported.
So, there is no more difference between generated-y and genhdr-y.

We see two users of genhdr-y, arch/{arm,x86}/include/uapi/asm/Kbuild.
They generate some headers in arch/{arm,x86}/include/generated/uapi/asm
directories, which are obviously exported.

Replace them with generated-y, and abolish genhdr-y.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>

Documentation/kbuild/makefiles.txt

@@ -45,10 +45,9 @@ This document describes the Linux kernel Makefiles.
 
 	=== 7 Kbuild syntax for exported headers
 		--- 7.1 no-export-headers
-		--- 7.2 genhdr-y
+		--- 7.2 generic-y
-		--- 7.3 generic-y
+		--- 7.3 generated-y
-		--- 7.4 generated-y
+		--- 7.4 mandatory-y
-		--- 7.5 mandatory-y
 
 	=== 8 Kbuild Variables
 	=== 9 Makefile language
@@ -1277,18 +1276,7 @@ See subsequent chapter for the syntax of the Kbuild file.
 	avoid exporting specific headers (e.g. kvm.h) on architectures that do
 	not support it. It should be avoided as much as possible.
 
-	--- 7.2 genhdr-y
+	--- 7.2 generic-y
-
-	genhdr-y specifies asm files to be generated.
-
-		Example:
-			#arch/x86/include/uapi/asm/Kbuild
-			genhdr-y += unistd_32.h
-			genhdr-y += unistd_64.h
-			genhdr-y += unistd_x32.h
-
-
-	--- 7.3 generic-y
 
 	If an architecture uses a verbatim copy of a header from
 	include/asm-generic then this is listed in the file
@@ -1315,11 +1303,10 @@ See subsequent chapter for the syntax of the Kbuild file.
 		Example: termios.h
 			#include <asm-generic/termios.h>
 
-	--- 7.4 generated-y
+	--- 7.3 generated-y
 
 	If an architecture generates other header files alongside generic-y
-	wrappers, and not included in genhdr-y, then generated-y specifies
+	wrappers, generated-y specifies them.
-	them.
 
 	This prevents them being treated as stale asm-generic wrappers and
 	removed.

arch/arm/include/uapi/asm/Kbuild

@@ -1,6 +1,6 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
-genhdr-y += unistd-common.h
+generated-y += unistd-common.h
-genhdr-y += unistd-oabi.h
+generated-y += unistd-oabi.h
-genhdr-y += unistd-eabi.h
+generated-y += unistd-eabi.h

arch/x86/include/uapi/asm/Kbuild

@@ -1,6 +1,6 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
-genhdr-y += unistd_32.h
+generated-y += unistd_32.h
-genhdr-y += unistd_64.h
+generated-y += unistd_64.h
-genhdr-y += unistd_x32.h
+generated-y += unistd_x32.h

scripts/Makefile.asm-generic

@@ -15,7 +15,7 @@ _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
 
 # Stale wrappers when the corresponding files are removed from generic-y
 # need removing.
-generated-y   := $(generic-y) $(genhdr-y) $(generated-y)
+generated-y   := $(generic-y) $(generated-y)
 all-files     := $(patsubst %, $(obj)/%, $(generated-y))
 old-headers   := $(wildcard $(obj)/*.h)
 unwanted      := $(filter-out $(all-files),$(old-headers))