From 011bf1254772b20083b1bab53f3aa58b1ec95eb1 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 18 Jul 2014 13:40:11 +0900 Subject: kbuild: allow to override Python command name The specification of Python 3 is largely different from that of Python 2. For example, arch/ia64/scripts/unwcheck.py seems to be written in Python 2, not compatible with Python 3. It is not a good idea to invoke python scripts with the hard-coded command name 'python'. The command 'python' could possibly be Python 3 on some systems. For that case, it is reasonable to allow to override the command name by giving 'PYTHON=python2' from the command line. The 'python' in arch/ia64/Makefile should be replaced with '$(PYTHON)'. Signed-off-by: Masahiro Yamada Cc: linux-ia64@vger.kernel.org Signed-off-by: Michal Marek --- Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 97b286128c1e..89fe23a0825c 100644 --- a/Makefile +++ b/Makefile @@ -366,6 +366,7 @@ GENKSYMS = scripts/genksyms/genksyms INSTALLKERNEL := installkernel DEPMOD = /sbin/depmod PERL = perl +PYTHON = python CHECK = sparse CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \ @@ -416,7 +417,7 @@ KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(S export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC export CPP AR NM STRIP OBJCOPY OBJDUMP -export MAKE AWK GENKSYMS INSTALLKERNEL PERL UTS_MACHINE +export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS -- cgit v1.2.3 From 866ced950bcd54820c3e571229356adc2b2dd72e Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 30 Jul 2014 20:50:18 +0200 Subject: kbuild: Support split debug info v4 This is an alternative approach to lower the overhead of debug info (as we discussed a few days ago) gcc 4.7+ and newer binutils have a new "split debug info" debug info model where the debug info is only written once into central ".dwo" files. This avoids having to copy it around multiple times, from the object files to the final executable. It lowers the disk space requirements. In addition it defaults to compressed debug data. More details here: http://gcc.gnu.org/wiki/DebugFission This patch adds a new option to enable it. It has to be an option, because it'll undoubtedly break everyone's debuginfo packaging scheme. gdb/objdump/etc. all still work, if you have new enough versions. I don't see big compile wins (maybe a second or two faster or so), but the object dirs with debuginfo get significantly smaller. My standard kernel config (slightly bigger than defconfig) shrinks from 2.9G disk space to 1.1G objdir (with non reduced debuginfo). I presume if you are IO limited the compile time difference will be larger. Only problem I've seen so far is that it doesn't play well with older versions of ccache (apparently fixed, see https://bugzilla.samba.org/show_bug.cgi?id=10005) v2: various fixes from Dirk Gouders. Improve commit message slightly. v3: Fix clean rules and improve Kconfig slightly v4: Fix merge error in last version (Sam Ravnborg) Clarify description that it mainly helps disk size. Cc: Dirk Gouders Signed-off-by: Andi Kleen Acked-by: Sam Ravnborg Signed-off-by: Michal Marek --- .gitignore | 1 + Makefile | 5 +++++ lib/Kconfig.debug | 15 +++++++++++++++ 3 files changed, 21 insertions(+) (limited to 'Makefile') diff --git a/.gitignore b/.gitignore index f4c0b091dcf4..e213b27f3921 100644 --- a/.gitignore +++ b/.gitignore @@ -34,6 +34,7 @@ *.gcno modules.builtin Module.symvers +*.dwo # # Top-level generic files diff --git a/Makefile b/Makefile index 89fe23a0825c..e5a269465f99 100644 --- a/Makefile +++ b/Makefile @@ -684,7 +684,11 @@ endif endif ifdef CONFIG_DEBUG_INFO +ifdef CONFIG_DEBUG_INFO_SPLIT +KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g) +else KBUILD_CFLAGS += -g +endif KBUILD_AFLAGS += -Wa,-gdwarf-2 endif @@ -1372,6 +1376,7 @@ clean: $(clean-dirs) @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \ \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \ -o -name '*.ko.*' \ + -o -name '*.dwo' \ -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \ -o -name '*.symtypes' -o -name 'modules.order' \ -o -name modules.builtin -o -name '.tmp_*.o.*' \ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 7cfcc1b8e101..910355da9d14 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -143,6 +143,21 @@ config DEBUG_INFO_REDUCED DEBUG_INFO build and compile times are reduced too. Only works with newer gcc versions. +config DEBUG_INFO_SPLIT + bool "Produce split debuginfo in .dwo files" + depends on DEBUG_INFO + help + Generate debug info into separate .dwo files. This significantly + reduces the build directory size for builds with DEBUG_INFO, + because it stores the information only once on disk in .dwo + files instead of multiple times in object files and executables. + In addition the debug information is also compressed. + + Requires recent gcc (4.7+) and recent gdb/binutils. + Any tool that packages or reads debug information would need + to know about the .dwo files and include them. + Incompatible with older versions of ccache. + config ENABLE_WARN_DEPRECATED bool "Enable __deprecated logic" default y -- cgit v1.2.3 From bfaf2dd3509bc73bf4a4cea0e72472755ed860e2 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 30 Jul 2014 20:50:19 +0200 Subject: Kbuild: Add a option to enable dwarf4 v2 I found that a lot of unresolvable variables when using gdb on the kernel become resolvable when dwarf4 is enabled. So add a Kconfig flag to enable it. It definitely increases the debug information size, but on the other hand this isn't so bad when debug fusion is used. v2: Use cc-option Signed-off-by: Andi Kleen Acked-by: Sam Ravnborg Signed-off-by: Michal Marek --- Makefile | 3 +++ lib/Kconfig.debug | 9 +++++++++ 2 files changed, 12 insertions(+) (limited to 'Makefile') diff --git a/Makefile b/Makefile index e5a269465f99..2fd21a58f5cf 100644 --- a/Makefile +++ b/Makefile @@ -691,6 +691,9 @@ KBUILD_CFLAGS += -g endif KBUILD_AFLAGS += -Wa,-gdwarf-2 endif +ifdef CONFIG_DEBUG_INFO_DWARF4 +KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,) +endif ifdef CONFIG_DEBUG_INFO_REDUCED KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 910355da9d14..d70f203ce710 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -158,6 +158,15 @@ config DEBUG_INFO_SPLIT to know about the .dwo files and include them. Incompatible with older versions of ccache. +config DEBUG_INFO_DWARF4 + bool "Generate dwarf4 debuginfo" + depends on DEBUG_INFO + help + Generate dwarf4 debug info. This requires recent versions + of gcc and gdb. It makes the debug information larger. + But it significantly improves the success of resolving + variables in gdb on optimized code. + config ENABLE_WARN_DEPRECATED bool "Enable __deprecated logic" default y -- cgit v1.2.3 From 26ea6bb1fef06c686be771903ecab0518af5c2de Mon Sep 17 00:00:00 2001 From: Behan Webster Date: Thu, 31 Jul 2014 21:08:25 -0700 Subject: kbuild, LLVMLinux: Supress warnings unless W=1-3 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit clang has more warnings enabled by default. Turn them off unless W is set. This patch fixes a logic bug where warnings in clang were disabled when W was set. Signed-off-by: Behan Webster Signed-off-by: Jan-Simon Möller Signed-off-by: Mark Charlebois Cc: bp@alien8.de Signed-off-by: Michal Marek --- Makefile | 1 + scripts/Makefile.extrawarn | 21 +++++++++++---------- 2 files changed, 12 insertions(+), 10 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 2fd21a58f5cf..4aef4f861238 100644 --- a/Makefile +++ b/Makefile @@ -663,6 +663,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare) # source of a reference will be _MergedGlobals and not on of the whitelisted names. # See modpost pattern 2 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,) +KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior) else # This warning generated too much noise in a regular build. diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 65643506c71c..f734033af219 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -26,16 +26,6 @@ warning-1 += $(call cc-option, -Wmissing-include-dirs) warning-1 += $(call cc-option, -Wunused-but-set-variable) warning-1 += $(call cc-disable-warning, missing-field-initializers) -# Clang -warning-1 += $(call cc-disable-warning, initializer-overrides) -warning-1 += $(call cc-disable-warning, unused-value) -warning-1 += $(call cc-disable-warning, format) -warning-1 += $(call cc-disable-warning, unknown-warning-option) -warning-1 += $(call cc-disable-warning, sign-compare) -warning-1 += $(call cc-disable-warning, format-zero-length) -warning-1 += $(call cc-disable-warning, uninitialized) -warning-1 += $(call cc-option, -fcatch-undefined-behavior) - warning-2 := -Waggregate-return warning-2 += -Wcast-align warning-2 += -Wdisabled-optimization @@ -64,4 +54,15 @@ ifeq ("$(strip $(warning))","") endif KBUILD_CFLAGS += $(warning) +else + +ifeq ($(COMPILER),clang) +KBUILD_CFLAGS += $(call cc-disable-warning, initializer-overrides) +KBUILD_CFLAGS += $(call cc-disable-warning, unused-value) +KBUILD_CFLAGS += $(call cc-disable-warning, format) +KBUILD_CFLAGS += $(call cc-disable-warning, unknown-warning-option) +KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare) +KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length) +KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized) +endif endif -- cgit v1.2.3