CS107 Assignment file couldn't compile, missing expat.h and thread_107.h files
-
25-06-2021 - |
Question
I was auditing cs107 at stanford online
The problem I ran into is with assignment 6, when I type "make" in terminal, the error message pops up. Basically, I miss two header files, which I guess can be got from the pre-compiled .lib file. But somehow it just doesn't work.
Here's part of the original make file:
CFLAGS = -D_REENTRANT -g -Wall -D__ostype_is_$(OSTYPE)__ -std=gnu99 -I/usr/class/cs107/include/ -Wno-unused-function $(DFLAG)
LDFLAGS = -L/usr/class/cs107/assignments/assn-6-rss-news-search-lib/$(OSTYPE) -L/usr/class/cs107/lib -lexpat -lrssnews $(PLATFORM_LIBS) $(THREAD_LIBS)
PFLAGS= -linker=/usr/pubsw/bin/ld -best-effort -threads=yes -max-threads=1000
Edit:
When I said "This is supposed to compile even without threading implementation", I meant that it should compile without FURTHER threading implementation by students.
So here's the error message with thread:
gcc -D_REENTRANT -g -Wall -D__ostype_is_linux__ -std=gnu99 -I/usr/class/cs107/include/ -Wno-unused-function -c -o rss-news-search.o rss-news-search.c
rss-news-search.c: In function ‘main’:
rss-news-search.c:109:3: warning: implicit declaration of function ‘InitThreadPackage’ [-Wimplicit-function-declaration]
gcc rss-news-search.o -D_REENTRANT -g -Wall -D__ostype_is_linux__ -std=gnu99 -I/usr/class/cs107/include/ -Wno-unused-function -L/home/h/cs107/assn-6-rss-news-search-lib/linux -L/usr/class/cs107/lib -L. -lexpat -lrssnews -lnsl -lpthread -lthread_107_linux -o rss-news-search
/usr/bin/ld: cannot find -lthread_107_linux
collect2: ld returned 1 exit status
make: *** [rss-news-search] Error 1
here's the error message without $(THREAD_LIBS):
gcc -D_REENTRANT -g -Wall -D__ostype_is_linux__ -std=gnu99 -I/usr/class/cs107/include/ -Wno-unused-function -c -o rss-news-search.o rss-news-search.c
rss-news-search.c: In function ‘main’:
rss-news-search.c:109:3: warning: implicit declaration of function ‘InitThreadPackage’ [-Wimplicit-function-declaration]
gcc rss-news-search.o -D_REENTRANT -g -Wall -D__ostype_is_linux__ -std=gnu99 -I/usr/class/cs107/include/ -Wno-unused-function -L/home/h/cs107/assn-6-rss-news-search-lib/linux -L/usr/class/cs107/lib -L. -lexpat -lrssnews -lnsl -lpthread -o rss-news-search
rss-news-search.o: In function `main':
/home/h/cs107/assn-6-rss-news-search/rss-news-search.c:109: undefined reference to `InitThreadPackage'
collect2: ld returned 1 exit status
make: *** [rss-news-search] Error 1
In the later case, if I comment out "InitThreadPackage", it compiles just fine.
Solution
This is the procedure to compile your project:
Create a file
assn-6-rss-news-search/thread_107.h
, and put this inside:/* Empty header file */
Copy the library
librssnews.a
fromassn-6-rss-news-search-lib/linux/
toassn-6-rss-news-search/
Modify the file
rss-news-search.c
by commenting the call to the function :InitThreadPackage
on line 109://InitThreadPackage(false);
Modify the
Makefile
to include the path to the current directory (to be able to link to the library you've copied earlierlibrssnews.a
):
The line 27 should look like this:
LDFLAGS = -L/usr/class/cs107/assignments/assn-6-rss-news-search-lib/$(OSTYPE) -L/usr/class/cs107/lib -L. -lexpat -lrssnews $(PLATFORM_LIBS) $(THREAD_LIBS)
Then:
make clean
make
EDIT :
When you got this error cannot find lthread_107_linux
, Edit your Makefile to remove this $(THREAD_LIBS)
on line 27:
LDFLAGS = -L/usr/class/cs107/assignments/assn-6-rss-news-search-lib/$(OSTYPE) -L/usr/class/cs107/lib -L. -lexpat -lrssnews $(PLATFORM_LIBS)
OTHER TIPS
The class-specific header files, like thread_107.h
are found in /usr/class/cs107/include/
on whatever machine the instructor is expecting the students to use. If you're not using that machine, you'll have to copy those include files or make your own.
The expat.h
file is from an open source library. You'll need to install the appropriate package on the system you're compiling on. On Ubuntu, that's sudo apt-get install libexpat1-dev
, but the package name should be similar on other distributions.