Commit 067c650c456e ("dtc: Use pkg-config to locate libyaml") added
'pkg-config --libs' to link libyaml installed in a non-standard
location.
yamltree.c includes <yaml.h>, but that commit did not add the search
path for <yaml.h>. If /usr/include/yaml.h does not exist, it fails to
build. A user can explicitly pass HOSTCFLAGS to work around it, but
the policy is not consistent.
There are two ways to deal with libraries in a non-default location.
[1] Use HOSTCFLAGS and HOSTLDFLAGS for additional search paths for
headers and libraries.
They are documented in Documentation/kbuild/kbuild.rst
$ make HOSTCFLAGS='-I <prefix>/include' HOSTLDFLAGS='-L <prefix>/lib'
[2] Use pkg-config
'pkg-config --cflags' for querying the header search path
'pkg-config --libs' for querying the lib and its path
If we go with pkg-config, use [2] consistently. Do not mix up
[1] and [2].
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---
scripts/dtc/Makefile | 3 +++
1 file changed, 3 insertions(+)
diff --git a/scripts/dtc/Makefile b/scripts/dtc/Makefile
index ef85f8b7d4a7..0b44917f981c 100644
--- a/scripts/dtc/Makefile
+++ b/scripts/dtc/Makefile
@@ -20,6 +20,9 @@ endif
HOST_EXTRACFLAGS += -DNO_YAML
else
dtc-objs += yamltree.o
+# To include <yaml.h> installed in a non-default path
+HOSTCFLAGS_yamltree.o := $(shell pkg-config --cflags yaml-0.1)
+# To link libyaml installed in a non-default path
HOSTLDLIBS_dtc := $(shell pkg-config yaml-0.1 --libs)
endif
--
2.25.1
