Reputation:
I'm pretty new to C and makefiles and thus do not completely understand the inner workings. As an assignment for school, I was told to make a spell checker, implementing three different ways. We were given a set of template files to work with.
In the main file (spell-checker.c
), I include hash.h
. This file gives me a few function prototypes.
I now have a few source files -- lets call them hash-glib.c
and hash-chain.c
. The first file uses glib and thus needs to include that library (hence the pkg-config stuff). I can manage to compile and run hash-glib.c
using the following makefile functions:
%.o: %.c
gcc $(CFLAGS) $< -c -o $@
hash-glib.o: hash-glib.c
gcc $< -c `pkg-config --cflags glib-2.0` $(CFLAGS)
libhash-glib.a: hash-glib.o
ar rcs libhash-glib.a $<
spell-checker-glib: spell-checker.c libhash-glib.a
gcc spell-checker.c -L. \
-lhash-glib `pkg-config --cflags --libs glib-2.0` $(CFLAGS) -o $@
I tried adding the following to get my desired result (to no avail):
libhash-chaining.a: hash-chaining.o
ar rcs libhash-chaining.a $<
spell-checker-chaining: spell-checker.c libhash-glib.a
gcc spell-checker.c -o $@ $(CFLAGS)
What am I missing here? (and for future reference -- what are some keywords I might look into?)
Thanks alot!
EDIT: This is the output:
$ make spell-checker-glib
gcc hash-glib.c -c `pkg-config --cflags glib-2.0` -std=c99 -Wall -Wextra -pedantic -O2
ar rcs libhash-glib.a hash-glib.o
gcc spell-checker.c -L. \
-lhash-glib `pkg-config --cflags --libs glib-2.0` -std=c99 -Wall -Wextra -pedantic -O2 -o spell-checker-glib
$ make spell-checker-chaining
gcc spell-checker.c -o spell-checker-chaining -std=c99 -Wall -Wextra -pedantic -O2
Undefined symbols for architecture x86_64:
"_hash_table_new", referenced from:
_main in ccGPxFvR.o
"_hash_table_insert", referenced from:
_main in ccGPxFvR.o
"_hash_table_fill", referenced from:
_main in ccGPxFvR.o
"_hash_table_size", referenced from:
_main in ccGPxFvR.o
"_hash_table_lookup", referenced from:
_main in ccGPxFvR.o
"_hash_table_destroy", referenced from:
_main in ccGPxFvR.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status
make: *** [spell-checker-chaining] Error 1
Upvotes: 1
Views: 223
Reputation: 99174
The problem is here:
spell-checker-chaining: spell-checker.c libhash-glib.a
gcc spell-checker.c -o $@ $(CFLAGS)
This compiles spell-checker.c
into spell-checker-chaining
. It requires that libhash-glib.a
exist, but doesn't use it, and doesn't mention hash-chaining
at all, so the compiler has no idea what it's supposed to use for hash functions.
I suggest you try the following:
spell-checker.o: spell-checker.c
# I'm kind of guessing here, I don't know what flags this object needs.
gcc $< `pkg-config --cflags` $(CFLAGS) -o $@
# I'm assuming spell-checker-chaining doesn't use glib.
spell-checker-chaining: spell-checker.o hash-chaining.o
gcc $^ -o $@ $(CFLAGS)
Upvotes: 2