Extend the platform dependent build rules.

* src/mkheader.c (mk_include_name): New.
(include_file): Implement '&' substitution.
(try_include_file): New.
(write_special): Use try_include_file and syscfg/.
(main): Add a new arg.
* configure.ac (CROSS_COMPILING): New am_conditional.
(HOST_TRIPLET_STRING): New ac_define.
* src/gen-posix-lock-obj.c (main): Print the host triplet.
* src/w32-lock-obj-pub.in: Move to ...
* src/syscfg/lock-obj-pub.mingw32.h: here.
* src/Makefile.am (lock_obj_pub): New.
(pre_mkheader_cmds): New.
(gpg-error.h): Run pre_mkheader_cmds.
(parts_of_gpg_error_h, lock-obj-pub.native.h): Do not use when
cross-compiling.

Signed-off-by: Werner Koch <wk@gnupg.org>

1 files changed, 24 insertions, 0 deletions

diff --git a/README b/README
index 73af551..3d4640c 100644
--- a/README
+++ b/README
@@ -95,6 +95,30 @@ version:
    ./autogen.sh --build-w64
 
 
+Cross-Compiling
+---------------
+
+Libgpg-error needs to figure out some platform specific properties.
+These are used to build the platform specific gpg-error.h file.  The
+detection is done during build time but can't be done when
+cross-compiling.  Thus if you run into an error during building you
+need to figure out these values.  You may use these commands:
+
+  build="$(build-aux/config.guess)"
+  ./configure --prefix=TARGETDIR --host=TARGET --build=$build
+  cd src
+  make gen-posix-lock-obj
+  scp gen-posix-lock-obj TARGET:
+  ssh TARGET ./gen-posix-lock-obj >tmp.h
+  mv tmp.h "syscfg/$(awk 'NR==1 {print $2}' tmp.h)"
+
+If you are using a VPATH build adjust accordingly.  If this all works
+for you (make sure to run the test programs on the target platform),
+please send the generated file to the gnupg-devel mailing list so that
+we can include it in the next release.
+
+
+
 Known Problems
 --------------