Ralf Wildenhues wrote: > Hi Harald, > > * Harald Dunkel wrote on Thu, May 12, 2005 at 10:45:40AM CEST: > >>How can I use target-specific variables in Makefiles >>generated by Automake? > > > In general, that is not possible. > For specific variables, like CFLAGS, CPPFLAGS, you may do this by using > > target_CFLAGS = ... > [snip] > > but for the compiler (CC, CXX, ..) this is not implemented. > Rationale: if you change the compiler, you most likely need to have a > separate configuration (configure, configure.ac) for it. Why would I need a new configure for another compiler? AFAIR the configure script is supposed to find the settings for either the compiler I choose, or for the default compiler. In my case I have 3 compilers, thats all. It should still be possible to configure these 3 compilers in parallel. > That may be > achieved by using a subpackage (see Automake docs on this subject). > This would mean that I have to manage 2 copies of the same sources. Hardly acceptable in a development environment. Anyway, if I introduce a line myexe: some_internal_tool_used_at_build_time then Automake shows the same misbehaviour: It assumes that I would like to redefine the build rule for myexe. Actually I just want to list additional dependencies. (I know myexe_DEPENDENCIES. But the computed default value does ignore configured libraries, which makes an incremental build very unreliable.) Reading automake.in sources I found a hint where the problem is: : # A rule has three parts: a list of targets, a list of dependencies, # and optionally actions. my $RULE_PATTERN = "^($TARGET_PATTERN(?:(?:\\\\\n|\\s)+$TARGET_PATTERN)*) *:([^=].*|)\$"; : The comment is wrong. The action is not optional, if you want to detect whether the author of a Makefile.am would like to define its own build rule. In this case Automake has to look at the next line: If it starts with a tab, _then_ it is safe to assume that the build-in rule should be ignored. > There is a workaround, however: you can override the value of CC in a > Makefile.am. I use this, for example, to invoke a compiler wrapper > (mpicc) in one subdir, and use the compiler itself in all others. > I have to support a single top level Makefile (thanx to Miller ;-). A possible workaround would be to add a pattern matching suffix rule, e.g. %_gcc3.a: CC=gcc3 But this still doesn't solve the problem with myexe. Regards Harri _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
