On Tue, 11 Jul 2017 05:08:56 -0000, Michael Witten wrote: > diff --git a/libtommath/Makefile.in b/libtommath/Makefile.in > index dbcd2a0..c06187a 100644 > --- a/libtommath/Makefile.in > +++ b/libtommath/Makefile.in > @@ -17,7 +17,7 @@ endif > ifneq ($V,1) > @echo " * ${CC} $@" > endif > - ${silent} ${CC} -c ${CFLAGS} $^ -o $@ > + ${silent} ${CC} -c ${CFLAGS} $*.c -o $@ > > #default files to install > ifndef LIBNAME
The above change is not quite correct; primarily, it breaks out-of-tree builds (which are already broken, and will be fixed shortly in another patch that I'll be submitting). The patch above alters the recipe for all object files (the rule not shown is `%.o: %.c'); in the original, the automatic variable `$^' is replaced with all of the prerequisites for the target in question, but this didn't work, because another part of this patch tells `make' that some of the prerequisites are header files, and thus `$^' expands to include those header files as well, which the compiler doesn't appreciate. The solution provided here just uses the pattern-matching stem of the target, provided by the automatic variable `$*', in order to construct the relevant `*.c' file. Alas, during an out-of-tree build, the stem is not enough to construct the path to the source code that needs to be compiled. In order to benefit from the search-for-prerequisites performed by `make', it's necessary to use the `$^' automatic variable, so the real solution to all of the above is just to filter the expansion of `$^' so that only `*.c' prerequisites are placed on the command line. More concretely, the above patch *should* look like this: diff --git a/libtommath/Makefile.in b/libtommath/Makefile.in index dbcd2a0..c06187a 100644 --- a/libtommath/Makefile.in +++ b/libtommath/Makefile.in @@ -17,7 +17,7 @@ endif ifneq ($V,1) @echo " * ${CC} $@" endif - ${silent} ${CC} -c ${CFLAGS} $^ -o $@ + ${silent} ${CC} -c ${CFLAGS} $(filter %.c,$^) -o $@ #default files to install ifndef LIBNAME As out-of-tree builds are already broken, there's little value in updating this particular patch; instead, the above improvement on this patch will be incorporated in a future patch that I'll submit soon for the purpose of fixing out-of-tree builds. Sincerely, Michael Witten