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authorLinus Torvalds <torvalds@linux-foundation.org>2020-08-09 14:10:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-09 14:10:26 -0700
commitfc80c51fd4b23ec007e88d4c688f2cac1b8648e7 (patch)
tree0a38fa91bbbe5de6c7c23bd65a6ab1d6593bbf93 /Documentation/kbuild
parent7a6b60441f02f6e22e7c0936ef16fa3f51832a48 (diff)
parent132305b3b474a85152302ceda4551384cce3904e (diff)
downloadlinux-fc80c51fd4b23ec007e88d4c688f2cac1b8648e7.tar.gz
linux-fc80c51fd4b23ec007e88d4c688f2cac1b8648e7.tar.xz
Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada: - run the checker (e.g. sparse) after the compiler - remove unneeded cc-option tests for old compiler flags - fix tar-pkg to install dtbs - introduce ccflags-remove-y and asflags-remove-y syntax - allow to trace functions in sub-directories of lib/ - introduce hostprogs-always-y and userprogs-always-y syntax - various Makefile cleanups * tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled kbuild: introduce hostprogs-always-y and userprogs-always-y kbuild: sort hostprogs before passing it to ifneq kbuild: move host .so build rules to scripts/gcc-plugins/Makefile kbuild: Replace HTTP links with HTTPS ones kbuild: trace functions in subdirectories of lib/ kbuild: introduce ccflags-remove-y and asflags-remove-y kbuild: do not export LDFLAGS_vmlinux kbuild: always create directories of targets powerpc/boot: add DTB to 'targets' kbuild: buildtar: add dtbs support kbuild: remove cc-option test of -ffreestanding kbuild: remove cc-option test of -fno-stack-protector Revert "kbuild: Create directory for target DTB" kbuild: run the checker after the compiler
Diffstat (limited to 'Documentation/kbuild')
-rw-r--r--Documentation/kbuild/Kconfig.recursion-issue-022
-rw-r--r--Documentation/kbuild/kconfig-language.rst18
-rw-r--r--Documentation/kbuild/llvm.rst2
-rw-r--r--Documentation/kbuild/makefiles.rst45
4 files changed, 55 insertions, 12 deletions
diff --git a/Documentation/kbuild/Kconfig.recursion-issue-02 b/Documentation/kbuild/Kconfig.recursion-issue-02
index b9fd56c4b57e..df245fd7670d 100644
--- a/Documentation/kbuild/Kconfig.recursion-issue-02
+++ b/Documentation/kbuild/Kconfig.recursion-issue-02
@@ -42,7 +42,7 @@
# "select FW_LOADER" [0], in the end the simple alternative solution to this
# problem consisted on matching semantics with newly introduced features.
#
-# [0] http://lkml.kernel.org/r/1432241149-8762-1-git-send-email-mcgrof@do-not-panic.com
+# [0] https://lkml.kernel.org/r/1432241149-8762-1-git-send-email-mcgrof@do-not-panic.com
mainmenu "Simple example to demo cumulative kconfig recursive dependency implication"
diff --git a/Documentation/kbuild/kconfig-language.rst b/Documentation/kbuild/kconfig-language.rst
index 39881b719782..1cf1aebdd6cd 100644
--- a/Documentation/kbuild/kconfig-language.rst
+++ b/Documentation/kbuild/kconfig-language.rst
@@ -540,8 +540,8 @@ followed by a test macro::
If you need to expose a compiler capability to makefiles and/or C source files,
`CC_HAS_` is the recommended prefix for the config option::
- config CC_HAS_STACKPROTECTOR_NONE
- def_bool $(cc-option,-fno-stack-protector)
+ config CC_HAS_ASM_GOTO
+ def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
Build as module only
~~~~~~~~~~~~~~~~~~~~
@@ -688,10 +688,10 @@ and real world requirements were not well understood. As it stands though
only reverse engineering techniques have been used to deduce semantics from
variability modeling languages such as Kconfig [3]_.
-.. [0] http://www.eng.uwaterloo.ca/~shshe/kconfig_semantics.pdf
-.. [1] http://gsd.uwaterloo.ca/sites/default/files/vm-2013-berger.pdf
-.. [2] http://gsd.uwaterloo.ca/sites/default/files/ase241-berger_0.pdf
-.. [3] http://gsd.uwaterloo.ca/sites/default/files/icse2011.pdf
+.. [0] https://www.eng.uwaterloo.ca/~shshe/kconfig_semantics.pdf
+.. [1] https://gsd.uwaterloo.ca/sites/default/files/vm-2013-berger.pdf
+.. [2] https://gsd.uwaterloo.ca/sites/default/files/ase241-berger_0.pdf
+.. [3] https://gsd.uwaterloo.ca/sites/default/files/icse2011.pdf
Full SAT solver for Kconfig
~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -710,10 +710,10 @@ such efforts somehow on Kconfig. There is enough interest from mentors of
existing projects to not only help advise how to integrate this work upstream
but also help maintain it long term. Interested developers should visit:
-http://kernelnewbies.org/KernelProjects/kconfig-sat
+https://kernelnewbies.org/KernelProjects/kconfig-sat
-.. [4] http://www.cs.cornell.edu/~sabhar/chapters/SATSolvers-KR-Handbook.pdf
-.. [5] http://gsd.uwaterloo.ca/sites/default/files/vm-2013-berger.pdf
+.. [4] https://www.cs.cornell.edu/~sabhar/chapters/SATSolvers-KR-Handbook.pdf
+.. [5] https://gsd.uwaterloo.ca/sites/default/files/vm-2013-berger.pdf
.. [6] https://cados.cs.fau.de
.. [7] https://vamos.cs.fau.de
.. [8] https://undertaker.cs.fau.de
diff --git a/Documentation/kbuild/llvm.rst b/Documentation/kbuild/llvm.rst
index c776b6eee969..2aac50b97921 100644
--- a/Documentation/kbuild/llvm.rst
+++ b/Documentation/kbuild/llvm.rst
@@ -76,7 +76,7 @@ Getting Help
Getting LLVM
-------------
-- http://releases.llvm.org/download.html
+- https://releases.llvm.org/download.html
- https://github.com/llvm/llvm-project
- https://llvm.org/docs/GettingStarted.html
- https://llvm.org/docs/CMake.html
diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index 6515ebc12b6f..b81b8913a5a3 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -368,6 +368,14 @@ more details, with real examples.
subdir-ccflags-y := -Werror
+ ccflags-remove-y, asflags-remove-y
+ These flags are used to remove particular flags for the compiler,
+ assembler invocations.
+
+ Example::
+
+ ccflags-remove-$(CONFIG_MCOUNT) += -pg
+
CFLAGS_$@, AFLAGS_$@
CFLAGS_$@ and AFLAGS_$@ only apply to commands in current
kbuild makefile.
@@ -375,6 +383,9 @@ more details, with real examples.
$(CFLAGS_$@) specifies per-file options for $(CC). The $@
part has a literal value which specifies the file that it is for.
+ CFLAGS_$@ has the higher priority than ccflags-remove-y; CFLAGS_$@
+ can re-add compiler flags that were removed by ccflags-remove-y.
+
Example::
# drivers/scsi/Makefile
@@ -387,6 +398,9 @@ more details, with real examples.
$(AFLAGS_$@) is a similar feature for source files in assembly
languages.
+ AFLAGS_$@ has the higher priority than asflags-remove-y; AFLAGS_$@
+ can re-add assembler flags that were removed by asflags-remove-y.
+
Example::
# arch/arm/kernel/Makefile
@@ -735,6 +749,10 @@ Both possibilities are described in the following.
hostprogs := lxdialog
always-y := $(hostprogs)
+ Kbuild provides the following shorthand for this:
+
+ hostprogs-always-y := lxdialog
+
This will tell kbuild to build lxdialog even if not referenced in
any rule.
@@ -817,7 +835,32 @@ The syntax is quite similar. The difference is to use "userprogs" instead of
5.4 When userspace programs are actually built
----------------------------------------------
- Same as "When host programs are actually built".
+ Kbuild builds userspace programs only when told to do so.
+ There are two ways to do this.
+
+ (1) Add it as the prerequisite of another file
+
+ Example::
+
+ #net/bpfilter/Makefile
+ userprogs := bpfilter_umh
+ $(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh
+
+ $(obj)/bpfilter_umh is built before $(obj)/bpfilter_umh_blob.o
+
+ (2) Use always-y
+
+ Example::
+
+ userprogs := binderfs_example
+ always-y := $(userprogs)
+
+ Kbuild provides the following shorthand for this:
+
+ userprogs-always-y := binderfs_example
+
+ This will tell Kbuild to build binderfs_example when it visits this
+ Makefile.
6 Kbuild clean infrastructure
=============================