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authorMasahiro Yamada <yamada.masahiro@socionext.com>2019-07-01 09:58:42 +0900
committerMasahiro Yamada <yamada.masahiro@socionext.com>2019-07-09 10:10:52 +0900
commit1e21cbfada87f697a2a7c450542a7d28925abee6 (patch)
treecbc197d95ca2fb327678bdd5276600ae3ddc72f8 /Documentation/kbuild
parentc93a0368aaa2962e6c89da20f79b8789b42e3387 (diff)
kbuild: support header-test-pattern-y
In my view, most of headers can be self-contained. So, it would be tedious to add every header to header-test-y explicitly. We usually end up with "all headers with some exceptions". There are two types in exceptions: [1] headers that are never compiled as standalone units For examples, include/linux/compiler-gcc.h is not intended for direct inclusion. We should always exclude such ones. [2] headers that are conditionally compiled as standalone units Some headers can be compiled only for particular architectures. For example, include/linux/arm-cci.h can be compiled only for arm/arm64 because it requires <asm/arm-cci.h> to exist. Clang can compile include/soc/nps/mtm.h only for arc because it contains an arch-specific register in inline assembler. So, you can write Makefile like this: header-test- += linux/compiler-gcc.h header-test-$(CONFIG_ARM) += linux/arm-cci.h header-test-$(CONFIG_ARM64) += linux/arm-cci.h header-test-$(CONFIG_ARC) += soc/nps/mtm.h The new syntax header-test-pattern-y will be useful to specify "the rest". The typical usage is like this: header-test-pattern-y += */*.h This will add all the headers in sub-directories to the test coverage, excluding $(header-test-). In this regards, header-test-pattern-y behaves like a weaker variant of header-test-y. Caveat: The patterns in header-test-pattern-y are prefixed with $(srctree)/$(src)/ but not $(objtree)/$(obj)/. Stale generated headers are often left over when you traverse the git history without cleaning. Wildcard patterns for $(objtree) may match to stale headers, which could fail to compile. One pitfall is $(srctree)/$(src)/ and $(objtree)/$(obj)/ point to the same directory for in-tree building. So, header-test-pattern-y should be used with care since it can potentially match to stale headers. Caveat2: You could use wildcard for header-test-. For example, header-test- += asm-generic/% ... will exclude headers in asm-generic directory. Unfortunately, the wildcard character is '%' instead of '*' here because this is evaluated by $(filter-out ...) whereas header-test-pattern-y is evaluated by $(wildcard ...). This is a kludge, but seems useful in some places... Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'Documentation/kbuild')
-rw-r--r--Documentation/kbuild/makefiles.txt10
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index 5080fec34609..b817e6cefb77 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -1025,6 +1025,16 @@ When kbuild executes, the following steps are followed (roughly):
i.e. compilable as standalone units. If CONFIG_HEADER_TEST is enabled,
this builds them as part of extra-y.
+ header-test-pattern-y
+
+ This works as a weaker version of header-test-y, and accepts wildcard
+ patterns. The typical usage is:
+
+ header-test-pattern-y += *.h
+
+ This specifies all the files that matches to '*.h' in the current
+ directory, but the files in 'header-test-' are excluded.
+
--- 6.7 Commands useful for building a boot image
Kbuild provides a few macros that are useful when building a