Add a configure option '--disable-doc' to disable building of the
documentation by the 'all' target.
Check for the required tools at configure time, and require them if
building documentation is enabled.
Even if building the documentation was diabled with '--disable-doc',
'make -C doc' at the top-level can still make the documentation, if the
documentation tools were found. If the tools were not found, 'missing'
is used to issue a warning about that.
Update instructions for building Cygwin appropriately.
(Building documentation remains the default to increase the chances of
noticing when building the documentation is broken.)
v2:
* Include tzmap.h in BUILT_SOURCES
* Make per-file flags appear after user-supplied CXXFLAGS, so they can
override optimization level.
* Correct .o files used to define symbols exported by libm.a
* Drop gcrt0.o mistakenly included in libgmon.a
* Add missing line continuations in GMON_FILES value
v3:
* use per-file flags for .c compilation
* override C{XX,}FLAGS, as they are set on the command line by top-level make
v4:
* Drop -Wno-error=write-strings from path_testsuite CXXFLAGS
v5:
* Update for changes in master
- Add -fno-threadsafe-statics to CXX flags
- Add hypotl.cc
- Remove fenv.cc (in favour of newlib), add fenv.c stub
- Add proc.5 manpage rules
Jon Turney