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authorLinus Torvalds <torvalds@linux-foundation.org>2018-08-15 12:09:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-15 12:09:03 -0700
commite026bcc561071c9895c73058b9cc6823defb7be6 (patch)
tree52f45a7d617d3143faecc2c901d6ef5ec5ee8620 /Documentation/kbuild/makefiles.txt
parent7c7b562c6f0a4fb13eee01cb39b111addfb165e6 (diff)
parent512ddf7d7db056edfed3159ea7cb4e4a5eefddd4 (diff)
Merge tag 'kbuild-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada: - verify depmod is installed before modules_install - support build salt in case build ids must be unique between builds - allow users to specify additional host compiler flags via HOST*FLAGS, and rename internal variables to KBUILD_HOST*FLAGS - update buildtar script to drop vax support, add arm64 support - update builddeb script for better debarch support - document the pit-fall of if_changed usage - fix parallel build of UML with O= option - make 'samples' target depend on headers_install to fix build errors - remove deprecated host-progs variable - add a new coccinelle script for refcount_t vs atomic_t check - improve double-test coccinelle script - misc cleanups and fixes * tag 'kbuild-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits) coccicheck: return proper error code on fail Coccinelle: doubletest: reduce side effect false positives kbuild: remove deprecated host-progs variable kbuild: make samples really depend on headers_install um: clean up archheaders recipe kbuild: add %asm-generic to no-dot-config-targets um: fix parallel building with O= option scripts: Add Python 3 support to tracing/draw_functrace.py builddeb: Add automatic support for sh{3,4}{,eb} architectures builddeb: Add automatic support for riscv* architectures builddeb: Add automatic support for m68k architecture builddeb: Add automatic support for or1k architecture builddeb: Add automatic support for sparc64 architecture builddeb: Add automatic support for mips{,64}r6{,el} architectures builddeb: Add automatic support for mips64el architecture builddeb: Add automatic support for ppc64 and powerpcspe architectures builddeb: Introduce functions to simplify kconfig tests in set_debarch builddeb: Drop check for 32-bit s390 builddeb: Change architecture detection fallback to use dpkg-architecture builddeb: Skip architecture detection when KBUILD_DEBARCH is set ...
Diffstat (limited to 'Documentation/kbuild/makefiles.txt')
-rw-r--r--Documentation/kbuild/makefiles.txt8
1 files changed, 7 insertions, 1 deletions
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index 048fc39a6b91..766355b1d221 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -661,7 +661,7 @@ Both possibilities are described in the following.
When compiling host programs, it is possible to set specific flags.
The programs will always be compiled utilising $(HOSTCC) passed
- the options specified in $(HOSTCFLAGS).
+ the options specified in $(KBUILD_HOSTCFLAGS).
To set flags that will take effect for all host programs created
in that Makefile, use the variable HOST_EXTRACFLAGS.
@@ -1105,6 +1105,12 @@ When kbuild executes, the following steps are followed (roughly):
target: source(s) FORCE
#WRONG!# $(call if_changed, ld/objcopy/gzip/...)
+ Note: if_changed should not be used more than once per target.
+ It stores the executed command in a corresponding .cmd
+ file and multiple calls would result in overwrites and
+ unwanted results when the target is up to date and only the
+ tests on changed commands trigger execution of commands.
+
ld
Link target. Often, LDFLAGS_$@ is used to set specific options to ld.