gh-104523: use dynamic rule for compiling libmpdec and libexpat

Before we had a separate rule for each source/object file. We can
use `$(foreach $(eval $(call ...)))` to dynamically derive rules to
avoid the repetition.

skip news (behavior preserving build system change)

Author: indygreg

Makefile.pre.in

@@ -863,50 +863,12 @@ python.worker.js: $(srcdir)/Tools/wasm/python.worker.js
 LIBMPDEC_CFLAGS=@LIBMPDEC_CFLAGS@ $(PY_STDMODULE_CFLAGS) $(CCSHARED)
 
 # "%.o: %c" is not portable
-Modules/_decimal/libmpdec/basearith.o: $(srcdir)/Modules/_decimal/libmpdec/basearith.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/basearith.c
+define libmpdec_compile
+$(1): $$(srcdir)/$$(patsubst %.o,%.c,$(1)) $$(LIBMPDEC_HEADERS) $$(PYTHON_HEADERS)
+	$$(CC) -c $$(LIBMPDEC_CFLAGS) -o $$@ $$<
+endef
 
-Modules/_decimal/libmpdec/constants.o: $(srcdir)/Modules/_decimal/libmpdec/constants.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/constants.c
-
-Modules/_decimal/libmpdec/context.o: $(srcdir)/Modules/_decimal/libmpdec/context.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/context.c
-
-Modules/_decimal/libmpdec/convolute.o: $(srcdir)/Modules/_decimal/libmpdec/convolute.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/convolute.c
-
-Modules/_decimal/libmpdec/crt.o: $(srcdir)/Modules/_decimal/libmpdec/crt.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/crt.c
-
-Modules/_decimal/libmpdec/difradix2.o: $(srcdir)/Modules/_decimal/libmpdec/difradix2.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/difradix2.c
-
-Modules/_decimal/libmpdec/fnt.o: $(srcdir)/Modules/_decimal/libmpdec/fnt.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/fnt.c
-
-Modules/_decimal/libmpdec/fourstep.o: $(srcdir)/Modules/_decimal/libmpdec/fourstep.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/fourstep.c
-
-Modules/_decimal/libmpdec/io.o: $(srcdir)/Modules/_decimal/libmpdec/io.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/io.c
-
-Modules/_decimal/libmpdec/mpalloc.o: $(srcdir)/Modules/_decimal/libmpdec/mpalloc.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/mpalloc.c
-
-Modules/_decimal/libmpdec/mpdecimal.o: $(srcdir)/Modules/_decimal/libmpdec/mpdecimal.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/mpdecimal.c
-
-Modules/_decimal/libmpdec/mpsignal.o: $(srcdir)/Modules/_decimal/libmpdec/mpsignal.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/mpsignal.c
-
-Modules/_decimal/libmpdec/numbertheory.o: $(srcdir)/Modules/_decimal/libmpdec/numbertheory.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/numbertheory.c
-
-Modules/_decimal/libmpdec/sixstep.o: $(srcdir)/Modules/_decimal/libmpdec/sixstep.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/sixstep.c
-
-Modules/_decimal/libmpdec/transpose.o: $(srcdir)/Modules/_decimal/libmpdec/transpose.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/transpose.c
+$(foreach src,$(LIBMPDEC_OBJS),$(eval $(call libmpdec_compile,$(src))))
 
 $(LIBMPDEC_A): $(LIBMPDEC_OBJS)
 	-rm -f $@
@@ -916,14 +878,12 @@ $(LIBMPDEC_A): $(LIBMPDEC_OBJS)
 # Build static libexpat.a
 LIBEXPAT_CFLAGS=@LIBEXPAT_CFLAGS@ $(PY_STDMODULE_CFLAGS) $(CCSHARED)
 
-Modules/expat/xmlparse.o: $(srcdir)/Modules/expat/xmlparse.c $(LIBEXPAT_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBEXPAT_CFLAGS) -o $@ $(srcdir)/Modules/expat/xmlparse.c
-
-Modules/expat/xmlrole.o: $(srcdir)/Modules/expat/xmlrole.c $(LIBEXPAT_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBEXPAT_CFLAGS) -o $@ $(srcdir)/Modules/expat/xmlrole.c
+define expat_compile
+$(1): $$(srcdir)/$$(patsubst %.o,%.c,$(1)) $$(LIBEXPAT_HEADERS) $$(PYTHON_HEADERS)
+	$$(CC) -c $$(LIBEXPAT_CFLAGS) -o $$@ $$<
+endef
 
-Modules/expat/xmltok.o: $(srcdir)/Modules/expat/xmltok.c $(LIBEXPAT_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBEXPAT_CFLAGS) -o $@ $(srcdir)/Modules/expat/xmltok.c
+$(foreach src,$(LIBEXPAT_OBJS),$(eval $(call expat_compile,$(src))))
 
 $(LIBEXPAT_A): $(LIBEXPAT_OBJS)
 	-rm -f $@