user/sven/linux.git/scripts/Kbuild.include, branch v4.14.94

kbuild: add .DELETE_ON_ERROR special target

2018-09-26T06:37:59Z

[ Upstream commit 9c2af1c7377a8a6ef86e5cabf80978f3dbbb25c0 ] If Make gets a fatal signal while a shell is executing, it may delete the target file that the recipe was supposed to update. This is needed to make sure that it is remade from scratch when Make is next run; if Make is interrupted after the recipe has begun to write the target file, it results in an incomplete file whose time stamp is newer than that of the prerequisites files. Make automatically deletes the incomplete file on interrupt unless the target is marked .PRECIOUS. The situation is just the same as when the shell fails for some reasons. Usually when a recipe line fails, if it has changed the target file at all, the file is corrupted, or at least it is not completely updated. Yet the file’s time stamp says that it is now up to date, so the next time Make runs, it will not try to update that file. However, Make does not cater to delete the incomplete target file in this case. We need to add .DELETE_ON_ERROR somewhere in the Makefile to request it. scripts/Kbuild.include seems a suitable place to add it because it is included from almost all sub-makes. Please note .DELETE_ON_ERROR is not effective for phony targets. The external module building should never ever touch the kernel tree. The following recipe fails if include/generated/autoconf.h is missing. However, include/config/auto.conf is not deleted since it is a phony target. PHONY += include/config/auto.conf include/config/auto.conf: $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \ echo >&2; \ echo >&2 " ERROR: Kernel configuration is invalid."; \ echo >&2 " include/generated/autoconf.h or $@ are missing.";\ echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \ echo >&2 ; \ /bin/false) Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Kbuild: fix # escaping in .cmd files for future Make

2018-07-11T14:29:21Z

commit 9564a8cf422d7b58f6e857e3546d346fa970191e upstream. I tried building using a freshly built Make (4.2.1-69-g8a731d1), but already the objtool build broke with orc_dump.c: In function ‘orc_dump’: orc_dump.c:106:2: error: ‘elf_getshnum’ is deprecated [-Werror=deprecated-declarations] if (elf_getshdrnum(elf, &nr_sections)) { Turns out that with that new Make, the backslash was not removed, so cpp didn't see a #include directive, grep found nothing, and -DLIBELF_USE_DEPRECATED was wrongly put in CFLAGS. Now, that new Make behaviour is documented in their NEWS file: * WARNING: Backward-incompatibility! Number signs (#) appearing inside a macro reference or function invocation no longer introduce comments and should not be escaped with backslashes: thus a call such as: foo := $(shell echo '#') is legal. Previously the number sign needed to be escaped, for example: foo := $(shell echo '\#') Now this latter will resolve to "\#". If you want to write makefiles portable to both versions, assign the number sign to a variable: C := \# foo := $(shell echo '$C') This was claimed to be fixed in 3.81, but wasn't, for some reason. To detect this change search for 'nocomment' in the .FEATURES variable. This also fixes up the two make-cmd instances to replace # with $(pound) rather than with \#. There might very well be other places that need similar fixup in preparation for whatever future Make release contains the above change, but at least this builds an x86_64 defconfig with the new make. Link: https://bugzilla.kernel.org/show_bug.cgi?id=197847 Cc: Randy Dunlap Signed-off-by: Rasmus Villemoes Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

kbuild: fix linker feature test macros when cross compiling with Clang

2018-03-24T10:01:29Z

commit 86a9df597cdd564d2d29c65897bcad42519e3678 upstream. I was not seeing my linker flags getting added when using ld-option when cross compiling with Clang. Upon investigation, this seems to be due to a difference in how GCC vs Clang handle cross compilation. GCC is configured at build time to support one backend, that is implicit when compiling. Clang is explicit via the use of `-target ` and ships with all supported backends by default. GNU Make feature test macros that compile then link will always fail when cross compiling with Clang unless Clang's triple is passed along to the compiler. For example: $ clang -x c /dev/null -c -o temp.o $ aarch64-linux-android/bin/ld -E temp.o aarch64-linux-android/bin/ld: unknown architecture of input file `temp.o' is incompatible with aarch64 output aarch64-linux-android/bin/ld: warning: cannot find entry symbol _start; defaulting to 0000000000400078 $ echo $? 1 $ clang -target aarch64-linux-android- -x c /dev/null -c -o temp.o $ aarch64-linux-android/bin/ld -E temp.o aarch64-linux-android/bin/ld: warning: cannot find entry symbol _start; defaulting to 00000000004002e4 $ echo $? 0 This causes conditional checks that invoke $(CC) without the target triple, then $(LD) on the result, to always fail. Suggested-by: Masahiro Yamada Signed-off-by: Nick Desaulniers Reviewed-by: Matthias Kaehlcke Signed-off-by: Masahiro Yamada Signed-off-by: Greg Hackmann Signed-off-by: Greg Kroah-Hartman

kbuild: trivial cleanups on the comments

2017-08-09T15:58:20Z

This is a bunch of trivial fixes and cleanups. Signed-off-by: Cao jin Signed-off-by: Masahiro Yamada

kbuild: Add __cc-option macro

2017-06-25T03:47:55Z

cc-option uses KBUILD_CFLAGS and KBUILD_CPPFLAGS when it determines whether an option is supported or not. This is fine for options used to build the kernel itself, however some components like the x86 boot code use a different set of flags. Add the new macro __cc-option which is a more generic version of cc-option with additional parameters. One parameter is the compiler with which the check should be performed, the other the compiler options to be used instead KBUILD_C*FLAGS. Refactor cc-option and hostcc-option to use __cc-option and move hostcc-option to scripts/Kbuild.include. Suggested-by: Arnd Bergmann Suggested-by: Masahiro Yamada Signed-off-by: Matthias Kaehlcke Acked-by: Arnd Bergmann Acked-by: Michal Marek Signed-off-by: Masahiro Yamada

kbuild: remove cc-option-align

2017-06-25T03:43:00Z

Documentation/kbuild/makefiles.txt says the change for align options occurred at GCC 3.0, and Documentation/process/changes.rst says the minimal supported GCC version is 3.2, so it should be safe to hard-code -falign* options. Fix the only user arch/x86/Makefile_32.cpu and remove cc-option-align. Signed-off-by: Masahiro Yamada Acked-by: Ingo Molnar

Merge tag 'kbuild-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2017-05-11T03:11:05Z

Pull Kbuild updates from Masahiro Yamada: - improve Clang support - clean up various Makefiles - improve build log visibility (objtool, alpha, ia64) - improve compiler flag evaluation for better build performance - fix GCC version-dependent warning - fix genksyms * tag 'kbuild-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (23 commits) kbuild: dtbinst: remove unnecessary __dtbs_install_prep target ia64: beatify build log for gate.so and gate-syms.o alpha: make short build log available for division routines alpha: merge build rules of division routines alpha: add $(src)/ rather than $(obj)/ to make source file path Makefile: evaluate LDFLAGS_BUILD_ID only once objtool: make it visible in make V=1 output kbuild: clang: add -no-integrated-as to KBUILD_[AC]FLAGS kbuild: Add support to generate LLVM assembly files kbuild: Add better clang cross build support kbuild: drop -Wno-unknown-warning-option from clang options kbuild: fix asm-offset generation to work with clang kbuild: consolidate redundant sed script ASM offset generation frv: Use OFFSET macro in DEF_*REG() kbuild: avoid conflict between -ffunction-sections and -pg on gcc-4.7 kbuild: Consolidate header generation from ASM offset information kbuild: use -Oz instead of -Os when using clang kbuild, LLVMLinux: Add -Werror to cc-option to support clang Kbuild: make designated_init attribute fatal kbuild: drop unneeded patterns '.*.orig' and '.*.rej' from distclean ...

kbuild, LLVMLinux: Add -Werror to cc-option to support clang

2017-04-11T19:34:20Z

Clang will warn about unknown warnings but will not return false unless -Werror is set. GCC will return false if an unknown warning is passed. Adding -Werror make both compiler behave the same. [arnd: it turns out we need the same patch for testing whether -ffunction-sections works right with gcc. I've build tested extensively with this patch applied, so let's just merge this one now.] Signed-off-by: Mark Charlebois Signed-off-by: Behan Webster Reviewed-by: Jan-Simon Möller Signed-off-by: Arnd Bergmann Acked-by: Kees Cook Signed-off-by: Masahiro Yamada

x86/build: Mostly disable '-maccumulate-outgoing-args'

2017-03-30T09:53:04Z

The GCC '-maccumulate-outgoing-args' flag is enabled for most configs, mostly because of issues which are no longer relevant. For most configs, and with most recent versions of GCC, it's no longer needed. Clarify which cases need it, and only enable it for those cases. Also produce a compile-time error for the ftrace graph + mcount + '-Os' case, which will otherwise cause runtime failures. The main benefit of '-maccumulate-outgoing-args' is that it prevents an ugly prologue for functions which have aligned stacks. But removing the option also has some benefits: more readable argument saves, smaller text size, and (presumably) slightly improved performance. Here are the object size savings for 32-bit and 64-bit defconfig kernels: text data bss dec hex filename 10006710 3543328 1773568 15323606 e9d1d6 vmlinux.x86-32.before 9706358 3547424 1773568 15027350 e54c96 vmlinux.x86-32.after text data bss dec hex filename 10652105 4537576 843776 16033457 f4a6b1 vmlinux.x86-64.before 10639629 4537576 843776 16020981 f475f5 vmlinux.x86-64.after That comes out to a 3% text size improvement on x86-32 and a 0.1% text size improvement on x86-64. Signed-off-by: Josh Poimboeuf Cc: Andrew Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20170316193133.zrj6gug53766m6nn@treble Signed-off-by: Ingo Molnar

Kbuild: Add cpp_its_S in ksym_dep_filter

2017-02-14T09:00:26Z

Add a new command cpp_its_S introduced in commit cf2a5e0bb4c6 ("MIPS: Support generating Flattened Image Trees (.itb)") to ksym_dep_filter handler - otherwise a warning is produced during the build of MIPS platforms (when vmlinux.*.itb target is chosen). Signed-off-by: Marcin Nowakowski Cc: Michal Marek Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15278/ Signed-off-by: James Hogan