[Crash-utility] RFC: crash extension module handling

[Jeff Moyer]

Dave Anderson <anderson at redhat.com> writes:

> Anyway, I've been tinkering with the extensions/Makefile to do such
> a thing, and have a crude addition that does just that, although
> it does the compile of all "new" C files every time whether they
> need it or not -- via the additional "contrib" target:
>
> 30c30
> < all: link_defs $(OBJECTS)
> ---
>> all: link_defs $(OBJECTS) contrib
> 43a44,50
>> contrib:
>> 	@for CFILE in `/bin/ls *.c | grep -v echo.c | grep -v dminfo.c
>> | grep -v 
> sial.c`; do \
>> 	   OUTPUT=`echo $$CFILE | cut -d. -f1`.so; \
>> 	   echo "gcc -nostartfiles -shared -rdynamic -o $$OUTPUT
>> $$CFILE -fPIC 
> -D$(TARGET) $(TARGET_CFLAGS)"; \
>> 	   gcc -nostartfiles -shared -rdynamic -o $$OUTPUT $$CFILE
>> -fPIC -D$(TARGET) 
> $(TARGET_CFLAGS); \
>>         done
>>
>
> It prevents the re-compilation of echo.c and dminfo.c, and of Luc
> Chouinard's upcoming sial.c extension module.  (SIAL is an alternative
> crash extension mechanism -- more on that when it's available...)
>
> Anyway, I've tried screwing around with the Makefile to use a generic
> *.so target, using $@, $(basename ...) and so on, but I'm not a Makefile
> master, and I cannot quite get it quite right, although I'm sure it can
> be done.
>
> So if anybody out there can do it cleaner than the "contrib" target above,
> I'd like to take a look.

Try this.

Cheers,

Jeff

--- crash-4.0/extensions/Makefile.orig	2007-09-20 16:35:36.000000000 -0400
+++ crash-4.0/extensions/Makefile	2007-09-20 16:35:42.000000000 -0400
@@ -26,18 +26,15 @@
 #  - create a compile stanza below, typically using "echo.so" as 
 #    a base template.
 # 
+CONTRIB_SRC := $(wildcard *.c)
+CONTRIB_SO := $(patsubst %.c,%.so,$(wildcard *.c))
 
-all: link_defs $(OBJECTS)
+all: link_defs $(OBJECTS) $(CONTRIB_SO)
 	
 link_defs:
 	@if [ ! -f defs.h ]; then \
 	  ln -s ../defs.h; fi 
 
-echo.so: ../defs.h echo.c
-	gcc -nostartfiles -shared -rdynamic -o echo.so echo.c -fPIC \
-				 		-D$(TARGET) $(TARGET_CFLAGS)
-
-dminfo.so: ../defs.h dminfo.c
-	gcc -nostartfiles -shared -rdynamic -o dminfo.so dminfo.c -fPIC \
-				 		-D$(TARGET) $(TARGET_CFLAGS)
-	
+$(CONTRIB_SO): $(CONTRIB_SRC)
+	gcc -nostartfiles -shared -rdynamic -o $@ $< -fPIC \
+						-D$(TARGET) $(TARGET_CFLAGS)