.PHONY: all clean
SOURCES := $(wildcard *.c)
-
REFS := $(SOURCES:%.c=$(WORKDIR)/%.ref)
-
-TESTS := $(SOURCES:%.c=$(WORKDIR)/%.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.o.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.os.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.osi.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.osir.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.oi.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.oir.prg)
-TESTS += $(SOURCES:%.c=$(WORKDIR)/%.or.prg)
+TESTS := $(foreach option,. .o. .os. .osi. .osir. .oi. .oir. .or.,$(SOURCES:%.c=$(WORKDIR)/%$(option)prg))
all: $(REFS) $(TESTS)