##                                                             -*- makefile -*-

## We keep a list of dependencies in `.depend' for each of the source
## files on which it depends.  When one of the source files is modified
## we remove its record from .depend and regenerate its dependencies,
## tacking them onto the end of .depend.  By including the .depend file
## into the makefile, we're telling make that the makefile depends on
## the dependency list in the .depend file.
##
## This is as fast as the `.d' method described in the GNU make manual
## for automatic dependencies, but has the added advantage that all
## dependencies are stored in one place.  The advantage over the
## `makedepend' program is that only those files that are out of date
## have dependency information rebuilt, and the Makefile is not
## modified.
##
## This is also where tracing information is updated.  The $(TRACE)
## program is run on each source file to make sure that the H5TRACE()
## macros are up to date.  If they are then the file is not modified,
## otherwise the file is changed and a backup is saved by appending a
## tilde to the file name.
##
$(srcdir)/Dependencies: .depend
	@if test "$(srcdir)" != "."; then                                     \
      echo '## This file is machine generated on GNU systems.' >$@;       \
      echo '## Only temporary changes may be made here.' >>$@;            \
      echo >>$@;                                                          \
      $(PERL) -p $(top_srcdir)/bin/distdep .depend >>$@;                  \
    else                                                                  \
      echo 'Dependencies cannot be built when $$srcdir == $$builddir';    \
    fi

.depend: $(LIB_SRC) $(TEST_SRC) $(PROG_SRC)
	@touch .depend
	@for dep in $? dummy; do                                              \
      if test $$dep != "dummy" -a -n "$(PERL)"; then                      \
        case "$$dep" in                                                   \
          *.c)                                                            \
            echo Building dependencies for $$dep;                         \
            obj=`basename $$dep .c`.lo;                                   \
            sed '\%^'"$$obj"':%,\%[^\\]$$%d' <$@ >$@- && mv $@- $@;       \
            $(TRACE) $$dep;                                               \
            $(CC) -MM -MG $(CPPFLAGS) $$dep 2>/dev/null >>$@;             \
            $(PERL) -w $(top_srcdir)/bin/dependencies --srcdir=$(srcdir) --top_srcdir=$(top_srcdir) --top_builddir=$(top_builddir) $@; \
            ;;                                                            \
        esac;                                                             \
      fi;                                                                 \
    done

-include .depend

