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| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2019-07-01 09:58:42 +0900 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2019-07-09 10:10:52 +0900 |
| commit | 1e21cbfada87f697a2a7c450542a7d28925abee6 (patch) | |
| tree | cbc197d95ca2fb327678bdd5276600ae3ddc72f8 /Documentation/kbuild | |
| parent | c93a0368aaa2962e6c89da20f79b8789b42e3387 (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.txt | 10 |
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 |