Remove the need to say 'HAVE_' in 'CONFIG'

Makefile

@@ -29,16 +29,16 @@ SOURCES=hello.cpp
 PRODUCTS=hello.exe
 
 # Define configuration options
-CONFIG=	HAVE_<stdio.h>		\
-	HAVE_<unistd.h>		\
-	HAVE_<nonexistent.h>	\
-	HAVE_<sys/time.h>	\
-	HAVE_<sys/improbable.h> \
-	HAVE_<iostream>		\
-	HAVE_clearenv		\
-	HAVE_libm		\
-	HAVE_liboony		\
-	HAVE_sbrk
+CONFIG=	<stdio.h>		\
+	<unistd.h>		\
+	<nonexistent.h>		\
+	<sys/time.h>		\
+	<sys/improbable.h> 	\
+	<iostream>		\
+	clearenv		\
+	libm			\
+	liboony			\
+	sbrk
 
 # Define what to test
 TESTS=product count-characters

README.md

@@ -254,16 +254,16 @@ header file.
 
 Here is an example from the sample `Makefile`:
 
-    CONFIG= HAVE_<stdio.h>                  \
-            HAVE_<unistd.h>                 \
-            HAVE_<nonexistent.h>            \
-            HAVE_<sys/time.h>               \
-            HAVE_<sys/improbable.h>         \
-            HAVE_<iostream>                 \
-            HAVE_clearenv                   \
-            HAVE_libm                       \
-            HAVE_liboony                    \
-            HAVE_sbrk
+    CONFIG= <stdio.h>                  \
+            <unistd.h>                 \
+            <nonexistent.h>            \
+            <sys/time.h>               \
+            <sys/improbable.h>         \
+            <iostream>                 \
+            clearenv                   \
+            libm                       \
+            liboony                    \
+            sbrk
 
 Here is what the generated `config.h` might look like:
 

rules.mk

@@ -372,7 +372,7 @@ endif
 NORM_CONFIG=$(subst <,.lt.,$(subst >,.gt.,$(subst /,.sl.,$(CONFIG))))
 ORIG_TARGET=$(subst .lt.,<,$(subst .gt.,>,$(subst .sl.,/,$*)))
 
-config.h: $(NORM_CONFIG:%=$(OBJDIR)/%)
+config.h: $(NORM_CONFIG:%=$(OBJDIR)/HAVE_%)
 	$(PRINT_GENERATE) cat $^ > $@
 
 # C standard headers, e.g. HAVE_<stdio.h>
@@ -380,24 +380,28 @@ $(OBJDIR)/HAVE_.lt.%.h.gt.: $(OBJDIR)/CONFIG_HAVE_%.c
 	$(PRINT_CONFIG) $(CC_CONFIG)
 $(OBJDIR)/CONFIG_HAVE_%.c: $(OBJDIR)/.mkdir
 	$(PRINT_GENERATE) echo '#include' "<$(ORIG_TARGET).h>" > "$@"; echo 'int main() { return 0; }' >> "$@"
+.PRECIOUS: $(OBJDIR)/CONFIG_HAVE_%.c
 
 # C++ Standard headers, e.g. HAVE_<iostream>
 $(OBJDIR)/HAVE_.lt.%.gt.: $(OBJDIR)/CONFIG_HAVE_%.cpp
 	$(PRINT_CONFIG) $(CXX_CONFIG)
 $(OBJDIR)/CONFIG_HAVE_%.cpp: $(OBJDIR)/.mkdir
 	$(PRINT_GENERATE) echo '#include' "<$(ORIG_TARGET)>" > "$@"; echo 'int main() { return 0; }' >> "$@"
+.PRECIOUS: $(OBJDIR)/CONFIG_HAVE_%.cpp
 
 # Library
 $(OBJDIR)/HAVE_lib%: $(OBJDIR)/CONFIG_LIB%.c
 	$(PRINT_LIBCONFIG) $(LIB_CONFIG)
 $(OBJDIR)/CONFIG_LIB%.c: $(OBJDIR)/.mkdir
 	$(PRINT_GENERATE) echo 'int main() { return 0; }' > "$@"
+.PRECIOUS: $(OBJDIR)/CONFIG_LIB%.c
 
 # Check if a function is present
 $(OBJDIR)/HAVE_%: $(OBJDIR)/CONFIG_CHECK_%.c
 	$(PRINT_CONFIG)	$(FN_CONFIG)
 $(OBJDIR)/CONFIG_CHECK_%.c: $(BUILD)config/check_%.c $(OBJDIR)/.mkdir
 	$(PRINT_COPY) cp $< $@
+.PRECIOUS: $(OBJDIR)/CONFIG_CHECK_%.c
 
 
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