All of lore.kernel.org
 help / color / mirror / Atom feed
From: Masahiro Yamada <yamada.masahiro@socionext.com>
To: linux-kbuild@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	devicetree@vger.kernel.org, linux-usb@vger.kernel.org,
	netdev@vger.kernel.org, x86@kernel.org,
	linux-media@vger.kernel.org
Subject: [PATCH 4/4] kbuild: remove 'addtree' and 'flags' magic for header search paths
Date: Mon, 13 May 2019 15:22:17 +0900	[thread overview]
Message-ID: <20190513062217.20750-5-yamada.masahiro@socionext.com> (raw)
In-Reply-To: <20190513062217.20750-1-yamada.masahiro@socionext.com>

The 'addtree' and 'flags' in scripts/Kbuild.include are so compilecated
and ugly.

As I mentioned in [1], Kbuild should stop automatic prefixing of header
search path options.

Instead, in-kernel Makefiles should explicitly add $(srctree)/ to
the search paths in the srctree.

Kbuild still caters to add $(srctree)/$(src) and $(objtree)/$(obj)
to the header search path for O= building, but never touches extra
compiler options from ccflags-y etc.

Going forward, in-kernel Makefiles should explicitly specify
$(srctree)/ if extra search paths are needed.

 Example)    ccflags-y += -I $(srctree)/foo/bar

You do not have to change external module Makefiles because $(src)
is already an absolute path for external modules.

 Example)    ccflags-y += -I $(src)/foo/bar

[1]: https://patchwork.kernel.org/patch/9632347/

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/Kbuild.include |  8 --------
 scripts/Makefile.host  | 12 +++++-------
 scripts/Makefile.lib   | 26 ++++++++------------------
 3 files changed, 13 insertions(+), 33 deletions(-)

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 7484b9d8272f..a675ce11a573 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -192,14 +192,6 @@ clean := -f $(srctree)/scripts/Makefile.clean obj
 # $(Q)$(MAKE) $(hdr-inst)=dir
 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
 
-# Prefix -I with $(srctree) if it is not an absolute path.
-# skip if -I has no parameter
-addtree = $(if $(patsubst -I%,%,$(1)), \
-$(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1)),$(1))
-
-# Find all -I options and call addtree
-flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
-
 # echo command.
 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
 echo-cmd = $(if $($(quiet)cmd_$(1)),\
diff --git a/scripts/Makefile.host b/scripts/Makefile.host
index 73b804197fca..b6a54bdf0965 100644
--- a/scripts/Makefile.host
+++ b/scripts/Makefile.host
@@ -67,18 +67,16 @@ _hostc_flags   = $(KBUILD_HOSTCFLAGS)   $(HOST_EXTRACFLAGS)   \
 _hostcxx_flags = $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
                  $(HOSTCXXFLAGS_$(basetarget).o)
 
-__hostc_flags	= $(_hostc_flags)
-__hostcxx_flags	= $(_hostcxx_flags)
-
+# $(objtree)/$(obj) for including generated headers from checkin source files
 ifeq ($(KBUILD_EXTMOD),)
 ifneq ($(srctree),.)
-__hostc_flags	= -I$(obj) $(call flags,_hostc_flags)
-__hostcxx_flags	= -I$(obj) $(call flags,_hostcxx_flags)
+_hostc_flags   += -I $(objtree)/$(obj)
+_hostcxx_flags += -I $(objtree)/$(obj)
 endif
 endif
 
-hostc_flags    = -Wp,-MD,$(depfile) $(__hostc_flags)
-hostcxx_flags  = -Wp,-MD,$(depfile) $(__hostcxx_flags)
+hostc_flags    = -Wp,-MD,$(depfile) $(_hostc_flags)
+hostcxx_flags  = -Wp,-MD,$(depfile) $(_hostcxx_flags)
 
 #####
 # Compile programs on the host
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 41e98fa66b91..1b412d4394ae 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -137,36 +137,26 @@ _c_flags += $(if $(patsubst n%,, \
 	$(CFLAGS_KCOV))
 endif
 
-__c_flags	= $(_c_flags)
-__a_flags	= $(_a_flags)
-__cpp_flags     = $(_cpp_flags)
-
-# If building the kernel in a separate objtree expand all occurrences
-# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
+# $(srctree)/$(src) for including checkin headers from generated source files
+# $(objtree)/$(obj) for including generated headers from checkin source files
 ifeq ($(KBUILD_EXTMOD),)
 ifneq ($(srctree),.)
-
-# -I$(obj) locates generated .h files
-# $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files
-#   and locates generated .h files
-# FIXME: Replace both with specific CFLAGS* statements in the makefiles
-__c_flags	= $(if $(obj),$(call addtree,-I$(src)) -I$(obj)) \
-		  $(call flags,_c_flags)
-__a_flags	= $(call flags,_a_flags)
-__cpp_flags     = $(call flags,_cpp_flags)
+_c_flags   += -I $(srctree)/$(src) -I $(objtree)/$(obj)
+_a_flags   += -I $(srctree)/$(src) -I $(objtree)/$(obj)
+_cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
 endif
 endif
 
 c_flags        = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
 		 -include $(srctree)/include/linux/compiler_types.h       \
-		 $(__c_flags) $(modkern_cflags)                           \
+		 $(_c_flags) $(modkern_cflags)                           \
 		 $(basename_flags) $(modname_flags)
 
 a_flags        = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
-		 $(__a_flags) $(modkern_aflags)
+		 $(_a_flags) $(modkern_aflags)
 
 cpp_flags      = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
-		 $(__cpp_flags)
+		 $(_cpp_flags)
 
 ld_flags       = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
 
-- 
2.17.1


      parent reply	other threads:[~2019-05-13  6:22 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-13  6:22 [PATCH 0/4] kbuild: remove 'addtree' and 'flags' magic Masahiro Yamada
2019-05-13  6:22 ` [PATCH 1/4] media: remove unneeded header search paths Masahiro Yamada
2019-05-13  6:22 ` [PATCH 2/4] media: prefix header search paths with $(srctree)/ Masahiro Yamada
2019-05-13  6:22 ` [PATCH 3/4] treewide: " Masahiro Yamada
2019-05-13  6:22 ` Masahiro Yamada [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190513062217.20750-5-yamada.masahiro@socionext.com \
    --to=yamada.masahiro@socionext.com \
    --cc=devicetree@vger.kernel.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=mchehab@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.