[libgpg-error PATCH] doc: if ever, depend on yat2m$(EXEEXT)

[Michael Haubenwallner]

Cygwin is not a "real" w32 system, and transparently hides the still
required '.exe' extension whenever possible.  Unfortunately, this does
not apply to Makefile targets, so we still have to use '.exe' here.
Fortunately, there is the portable EXEEXT Makefile variable we can use.

Furthermore, we want to use a detected yat2m utility only if we are
cross compiling, but we do not need a Makefile dependency then.
Otherwise, the just created yat2m utility should work fine.

* doc/Makefile.am (CROSS_COMPILING, HAVE_YAT2M): Set empty YAT2M_DEP.
(not CROSS_COMPILING): Ignore detected yat2m, use local one.  Use EXEEXT
in YAT2M_DEP rather than explicit '.exe' based on HAVE_W32_SYSTEM.
--

Analysis for the problem on Cygwin when YAT2M_DEP does lack EXEEXT:
* make has a default rule to create 'yat2m' from 'yat2m.c' (uses CC)
* gcc transparently adds '.exe' when creating executables for Cygwin
* 'yat2m.exe' created from default rule does perfectly work
* automake generates the 'yat2m$(EXEEXT)' Makefile target (uses libtool)
* with EXEEXT=.exe, Makefile has both targets 'yat2m' and 'yat2m.exe'
* parallel make does execute commands for both targets in parallel
* both targets really create 'yat2m.exe', overwriting each other...
---
 doc/Makefile.am | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/doc/Makefile.am b/doc/Makefile.am
index 6f3e5a1..3fff0a6 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -37,26 +37,21 @@ myman_pages   = gpg-error-config.1
 
 man_MANS = $(myman_pages)
 
+if CROSS_COMPILING
 if HAVE_YAT2M
 YAT2M_CMD = $(YAT2M)
-YAT2M_DEP = $(YAT2M)
+YAT2M_DEP =
 else
-if CROSS_COMPILING
 YAT2M_CMD = ./yat2m-for-build
 YAT2M_DEP = yat2m-for-build
 CLEANFILES += yat2m-for-build
 
 yat2m-for-build: yat2m.c
 	$(CC_FOR_BUILD) -o $@ $(srcdir)/yat2m.c
-else
-if HAVE_W32_SYSTEM
-YAT2M_CMD = ./yat2m.exe
-YAT2M_DEP = yat2m.exe
-else
-YAT2M_CMD = ./yat2m
-YAT2M_DEP = yat2m
-endif
 endif
+else
+YAT2M_CMD = ./yat2m$(EXEEXT)
+YAT2M_DEP = yat2m$(EXEEXT)
 endif
 
 yat2m-stamp: $(myman_sources) $(srcdir)/version.texi
-- 
2.16.1