[Buildroot] [PATCH 1/1] package/brltty: fix build with expat

[Thomas Petazzoni]

Hello Fabrice,

On Sun, 29 Sep 2019 10:40:04 +0200
Fabrice Fontaine <fontaine.fabrice at gmail.com> wrote:

> tbl2hex is a host command line that is built with:
> 
> TBL2HEX_OBJECTS_FOR_BUILD = tbl2hex.$(O_FOR_BUILD) $(PROGRAM_OBJECTS_FOR_BUILD) dataarea.$(O_FOR_BUILD) ttb_compile.$(O_FOR_BUILD) ttb_native.$(O_FOR_BUILD) atb_compile.$(O_FOR_BUILD) ctb_compile.$(O_FOR_BUILD) cldr.$(O_FOR_BUILD)
> TBL2HEX_OBJECTS = $(TBL2HEX_OBJECTS_FOR_BUILD:.$(O_FOR_BUILD)=.$B)
> 
> tbl2hex$(X_FOR_BUILD): $(TBL2HEX_OBJECTS)
> $(CC_FOR_BUILD) $(LDFLAGS_FOR_BUILD) -o $@ $(TBL2HEX_OBJECTS) $(EXPAT_LIBS_FOR_BUILD) $(LDLIBS_FOR_BUILD)
> 
> So build fails if expat is enabled on target but not found on host:
> 
> gcc -DFOR_BUILD -I. -I. -I./../Programs -I../Programs -I../Headers -I./.. -I.. -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -D_DEFAULT_SOURCE -D_POSIX_C_SOURCE=2 -D_BSD_SOURCE -D_XOPEN_SOURCE=500 -D_XOPEN_SOURCE_EXTENDED -D_GNU_SOURCE  -D_DEFAULT_SOURCE -D_POSIX_C_SOURCE=2 -D_BSD_SOURCE -D_XOPEN_SOURCE=500 -D_XOPEN_SOURCE_EXTENDED -D_GNU_SOURCE -DHAVE_CONFIG_H -g -O2 -std=gnu99 -Wall -Werror=format-security -o cldr.build.o -c cldr.c
> cldr.c:31:10: fatal error: expat.h: No such file or directory
>  #include <expat.h>
>           ^~~~~~~~~
> 
> To fix this issue, build host-expat if needed
> 
> Fixes:
>  - http://autobuild.buildroot.org/results/362cfb57e4a91a066493269d8078d931529ddf69
> 
> Signed-off-by: Fabrice Fontaine <fontaine.fabrice at gmail.com>

Maybe it's because it's late and I'm no longer thinking properly, but
do you understand how disabling expat prevents the cldr program from
being built, and therefore the tbl2hex utility tool from being built ?
They seem to be unconditionally built by Programs/Makefile.in.

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com