Importing NanoBlogger post "More make idoms"

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+[[!meta  title="More make idoms"]]
+[[!meta  date="2008-08-31 20:27:09"]]
+I'm rather proud of this one (can you tell I'm overhauling sawsim's
+Makefile ;).
+
+    $ cat Makefile
+    FILES = a b
+    DS = src
+    DT = targ
+
+    all : $(FILES:%=$(DT)/%)
+            @echo "got $^"
+            @echo "done"
+
+    clean :
+            rm -rf $(DT)
+
+    .SECONDEXPANSION:
+    #$(FILES:%=$(DT)/%) : $$($$@:$(DT)/%=$(DS)/%) $(DT)
+    #              This colon --^ produces: "target pattern contains no `%'."
+    # Instead use this idom --v
+    $(FILES:%=$(DT)/%) : $$(subst $(DT),$(DS),$$@) $(DT)
+            @echo "looking for $< for $@"
+
+    $(DT) :
+            mkdir $@
+    % :
+            @echo "missing rule for $@"
+
+    $ make
+    looking for src/a for targ/a
+    looking for src/b for targ/b
+    got targ/a targ/b
+    done
+
+Of course you could accomplish the same effect with
+
+   $(DT)/% : $(SRC)/%
+           @echo "looking for $< for %@"
+
+but what fun is that? ;)
+
+[[!tag  programming]]