From patchwork Mon May 28 09:21:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 137065 Delivered-To: patch@linaro.org Received: by 2002:a2e:9706:0:0:0:0:0 with SMTP id r6-v6csp2596774lji; Mon, 28 May 2018 02:30:30 -0700 (PDT) X-Google-Smtp-Source: AB8JxZpNYausoUniSWz/VE8gJiH03sZ4USjyl7L0sApgvHaVneD5Kc9qk9BYU4Vr2Jxo3xMNUyrF X-Received: by 2002:a17:902:20c9:: with SMTP id v9-v6mr12931808plg.206.1527499830151; Mon, 28 May 2018 02:30:30 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1527499830; cv=none; d=google.com; s=arc-20160816; b=u3jRf3qRQUPTUnOWmPpzmKiRpCdga/oWKvh6c4bQGp/2mpt9AY1+Zx6nNN8g8QI0d6 rpdbk7MPtTdLWyWyugVZaMO+Ar083m+ZaA3kARnRJWA75beAVqGUlzYMIbhWpqg5vaf7 CPIU64cdEzyNfJRLZXkojZy6t3ZNn/u/wxoYnnzjucPLAQBdrVzZ15MLKIn04KEf0o0D Iyob5jHwLL2x7Aj01zEI1ID5YC/eY7cfyaZ3LIOlRgs3K+5vEl3otyO2MeouJoLYc0Rm x/BHxzRCoUZRrcL40g2SalXzUrIM8u/+Cb8THBTptQhGuTRbS0ELP+moW0SHNlCPw6An mAJw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:dkim-filter :arc-authentication-results; bh=uID5QwVz8O5eC4qs7omIna/BbDyuws8qjBNDHia+jKc=; b=z3Rbf/JwPlkKCjPuUSrR23G70008kYdr49mXD5Ip/gyx4tLhEJjoTHLzlHaIxSFbi/ Fhgk3MTdl9MgJbWzPQkTLPD6lx/GDchKGvqmSyp2bfz/sfZmgD3WHFRuPvKMQJdT2QCs WzuJ857A74+PsNnSb6fEprSTw0ttuLlfVb0wGqVateVDed5vuurnu8QCxu6060DhCnDO oimusLVPHFkzG2QB+xeT95cGmrQSKH2ajzrO+c5jxaOtjb9sBYT58Q7bz2PpyQ29zPV+ wcn6VV5NMzO90p2pIwnFj5mhiHbrn9ww4b4lBQDntprpMvo3mFhRLq5HXZEmfHU3ALei cSFg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@nifty.com header.s=dec2015msa header.b=Z35n73Ux; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 136-v6si5492350pgf.604.2018.05.28.02.30.29; Mon, 28 May 2018 02:30:30 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@nifty.com header.s=dec2015msa header.b=Z35n73Ux; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932179AbeE1Ja1 (ORCPT + 30 others); Mon, 28 May 2018 05:30:27 -0400 Received: from conuserg-10.nifty.com ([210.131.2.77]:21545 "EHLO conuserg-10.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754278AbeE1JYO (ORCPT ); Mon, 28 May 2018 05:24:14 -0400 Received: from grover.sesame (FL1-125-199-20-195.osk.mesh.ad.jp [125.199.20.195]) (authenticated) by conuserg-10.nifty.com with ESMTP id w4S9MInI027506; Mon, 28 May 2018 18:22:20 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-10.nifty.com w4S9MInI027506 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1527499340; bh=uID5QwVz8O5eC4qs7omIna/BbDyuws8qjBNDHia+jKc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z35n73UxDVdFdIMdWsyIs7/RRDNRLzToReHh/Hln5dJxq3v+z7KyBVFK6nCCdWVBo VJn2ACJqTv5/jHyrouQYL8gu5YEu5kPLveJ/I26DqLgYCWIi6lpDnukXWhDqLsxMcp tirHM8U+UwQI9vbfufsPl8S5n7ICm1K/FCWSLkPA5su2I8JX2o9693Uxj/Jc+9H2A3 BZCLv+ROi1glWk90PbXr1OqONM5OIMPAzY/pcdr88gcVGvCPPPDMKl9ja92ewy5s/F ry2m1qhIDS/BB+vWEy5lAMQbgs6ra1ZKkeG4G0PHWY15Ad7WX3mbxwGHpkfc8Czy/h HDc7WWEtUwmaA== X-Nifty-SrcIP: [125.199.20.195] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Kees Cook , Nicholas Piggin , "Luis R . Rodriguez" , Randy Dunlap , Ulf Magnusson , Sam Ravnborg , Linus Torvalds , Masahiro Yamada Subject: [PATCH v5 01/31] kbuild: remove kbuild cache Date: Mon, 28 May 2018 18:21:38 +0900 Message-Id: <1527499328-13213-2-git-send-email-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1527499328-13213-1-git-send-email-yamada.masahiro@socionext.com> References: <1527499328-13213-1-git-send-email-yamada.masahiro@socionext.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kbuild cache was introduced to remember the result of shell commands, some of which are expensive to compute, such as $(call cc-option,...). However, this turned out not so clever as I had first expected. Actually, it is problematic. For example, "$(CC) -print-file-name" is cached. If the compiler is updated, the stale search path causes build error, which is difficult to figure out. Another problem scenario is cache files could be touched while install targets are running under the root permission. We can patch them if desired, but the build infrastructure is getting uglier and uglier. Now, we are going to move compiler flag tests to the configuration phase. If this is completed, the result of compiler tests will be naturally cached in the .config file. We will not have performance issues of incremental building since this testing only happens at Kconfig time. To start this work with a cleaner code base, remove the kbuild cache first. Revert the following commits: Commit 9a234a2e3843 ("kbuild: create directory for make cache only when necessary") Commit e17c400ae194 ("kbuild: shrink .cache.mk when it exceeds 1000 lines") Commit 4e56207130ed ("kbuild: Cache a few more calls to the compiler") Commit 3298b690b21c ("kbuild: Add a cache for generated variables") Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook --- Changes in v5: None Changes in v4: None Changes in v3: None Changes in v2: None Makefile | 5 +-- scripts/Kbuild.include | 101 +++++++------------------------------------------ 2 files changed, 16 insertions(+), 90 deletions(-) -- 2.7.4 diff --git a/Makefile b/Makefile index 56ba070..02202d3 100644 --- a/Makefile +++ b/Makefile @@ -504,7 +504,7 @@ KBUILD_CFLAGS += $(call cc-option,-fno-PIE) KBUILD_AFLAGS += $(call cc-option,-fno-PIE) # check for 'asm goto' -ifeq ($(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y) +ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y) CC_HAVE_ASM_GOTO := 1 KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO @@ -807,7 +807,7 @@ KBUILD_CFLAGS += $(call cc-option,-fdata-sections,) endif # arch Makefile may override CC so keep this after arch Makefile is included -NOSTDINC_FLAGS += -nostdinc -isystem $(call shell-cached,$(CC) -print-file-name=include) +NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) CHECKFLAGS += $(NOSTDINC_FLAGS) # warn about C99 declaration after statement @@ -1625,7 +1625,6 @@ clean: $(clean-dirs) -o -name '*.asn1.[ch]' \ -o -name '*.symtypes' -o -name 'modules.order' \ -o -name modules.builtin -o -name '.tmp_*.o.*' \ - -o -name .cache.mk \ -o -name '*.c.[012]*.*' \ -o -name '*.ll' \ -o -name '*.gcno' \) -type f -print | xargs rm -f diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 50cee53..925a851 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -8,8 +8,6 @@ squote := ' empty := space := $(empty) $(empty) space_escape := _-_SPACE_-_ -right_paren := ) -left_paren := ( pound := \# ### @@ -83,71 +81,6 @@ cc-cross-prefix = \ echo $(c); \ fi))) -# Tools for caching Makefile variables that are "expensive" to compute. -# -# Here we want to help deal with variables that take a long time to compute -# by making it easy to store these variables in a cache. -# -# The canonical example here is testing for compiler flags. On a simple system -# each call to the compiler takes 10 ms, but on a system with a compiler that's -# called through various wrappers it can take upwards of 100 ms. If we have -# 100 calls to the compiler this can take 1 second (on a simple system) or 10 -# seconds (on a complicated system). -# -# The "cache" will be in Makefile syntax and can be directly included. -# Any time we try to reference a variable that's not in the cache we'll -# calculate it and store it in the cache for next time. - -# Include values from last time -make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk -$(make-cache): ; --include $(make-cache) - -cached-data := $(filter __cached_%, $(.VARIABLES)) - -# If cache exceeds 1000 lines, shrink it down to 500. -ifneq ($(word 1000,$(cached-data)),) -$(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \ - mv $(make-cache).tmp $(make-cache)) -endif - -create-cache-dir := $(if $(KBUILD_SRC),$(if $(cache-data),,1)) - -# Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios) -# -# Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_' -__sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$(subst \,_,$(subst =,_,$(subst $(space),_,$(subst $(comma),_,$(subst :,_,$(1))))))))) - -# Usage: $(call shell-cached,shell_command) -# Example: $(call shell-cached,md5sum /usr/bin/gcc) -# -# If we've already seen a call to this exact shell command (even in a -# previous invocation of make!) we'll return the value. If not, we'll -# compute it and store the result for future runs. -# -# This is a bit of voodoo, but basic explanation is that if the variable -# was undefined then we'll evaluate the shell command and store the result -# into the variable. We'll then store that value in the cache and finally -# output the value. -# -# NOTE: The $$(2) here isn't actually a parameter to __run-and-store. We -# happen to know that the caller will have their shell command in $(2) so the -# result of "call"ing this will produce a reference to that $(2). The reason -# for this strangeness is to avoid an extra level of eval (and escaping) of -# $(2). -define __run-and-store -ifeq ($(origin $(1)),undefined) - $$(eval $(1) := $$(shell $$(2))) -ifeq ($(create-cache-dir),1) - $$(shell mkdir -p $(dir $(make-cache))) - $$(eval create-cache-dir :=) -endif - $$(shell echo '$(1) := $$($(1))' >> $(make-cache)) -endif -endef -__shell-cached = $(eval $(call __run-and-store,$(1)))$($(1)) -shell-cached = $(call __shell-cached,__cached_$(call __sanitize-opt,$(1)),$(1)) - # output directory for tests below TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) @@ -155,36 +88,30 @@ TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) # Exit code chooses option. "$$TMP" serves as a temporary file and is # automatically cleaned up. -__try-run = set -e; \ +try-run = $(shell set -e; \ TMP="$(TMPOUT).$$$$.tmp"; \ TMPO="$(TMPOUT).$$$$.o"; \ if ($(1)) >/dev/null 2>&1; \ then echo "$(2)"; \ else echo "$(3)"; \ fi; \ - rm -f "$$TMP" "$$TMPO" - -try-run = $(shell $(__try-run)) - -# try-run-cached -# This works like try-run, but the result is cached. -try-run-cached = $(call shell-cached,$(__try-run)) + rm -f "$$TMP" "$$TMPO") # as-option # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) -as-option = $(call try-run-cached,\ +as-option = $(call try-run,\ $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) # as-instr # Usage: cflags-y += $(call as-instr,instr,option1,option2) -as-instr = $(call try-run-cached,\ +as-instr = $(call try-run,\ printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) # __cc-option # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) -__cc-option = $(call try-run-cached,\ +__cc-option = $(call try-run,\ $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) # Do not attempt to build with gcc plugins during cc-option tests. @@ -204,23 +131,23 @@ hostcc-option = $(call __cc-option, $(HOSTCC),\ # cc-option-yn # Usage: flag := $(call cc-option-yn,-march=winchip-c6) -cc-option-yn = $(call try-run-cached,\ +cc-option-yn = $(call try-run,\ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) # cc-disable-warning # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) -cc-disable-warning = $(call try-run-cached,\ +cc-disable-warning = $(call try-run,\ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) # cc-name # Expands to either gcc or clang -cc-name = $(call shell-cached,$(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc) +cc-name = $(shell $(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc) # cc-version -cc-version = $(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) +cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) # cc-fullversion -cc-fullversion = $(call shell-cached,$(CONFIG_SHELL) \ +cc-fullversion = $(shell $(CONFIG_SHELL) \ $(srctree)/scripts/gcc-version.sh -p $(CC)) # cc-ifversion @@ -233,21 +160,21 @@ cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo # cc-ldoption # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both) -cc-ldoption = $(call try-run-cached,\ +cc-ldoption = $(call try-run,\ $(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) # ld-option # Usage: LDFLAGS += $(call ld-option, -X) -ld-option = $(call try-run-cached, $(LD) $(LDFLAGS) $(1) -v,$(1),$(2)) +ld-option = $(call try-run, $(LD) $(LDFLAGS) $(1) -v,$(1),$(2)) # ar-option # Usage: KBUILD_ARFLAGS := $(call ar-option,D) # Important: no spaces around options -ar-option = $(call try-run-cached, $(AR) rc$(1) "$$TMP",$(1),$(2)) +ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2)) # ld-version # Note this is mainly for HJ Lu's 3 number binutil versions -ld-version = $(call shell-cached,$(LD) --version | $(srctree)/scripts/ld-version.sh) +ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh) # ld-ifversion # Usage: $(call ld-ifversion, -ge, 22252, y)