compile

#!/bin/sh

### INITIAL

set -e    # halt on first error

set -x    # print out all commands

link=all  # link all binaries by default
linked=no # track whether we linked

case $1 in  
  -nolink) link=none ; shift ;;  # don't link
  -link)   link="$2" ; shift ; shift ;;  # link only one binary
esac

CC=gcc

# compile and link against course software and netpbm library
CFLAGS="-I. -I/csc/411/include -I/usr/local/cii/include -I/usr/local/include"
LIBS="-lcii -lnetpbm -lm -lbitpack"
LFLAGS="-L/usr/local/cii/lib -L/usr/local/lib -L/csc/411/lib"

# these flags max out warnings and debug info
FLAGS="-no-pie -g -O0 -Wall -Wextra -Werror -Wfatal-errors -std=c99 -pedantic"

rm -f *.o  # make sure no object files are left hanging around

case $# in
  0) set *.c ;; # if no args are given, compile all .c files
esac

# compile each argument to a .o file
for cfile 
do
  gcc $FLAGS $CFLAGS -c $cfile
done

### MIDDLE 
# link together .o files + libraries to make executable binaries
# using one case statement per executable binary
case $link in 
    all|um) $CC $FLAGS $LFLAGS -o um um.o program_loader.o execute.o memory.o \
                                     segment.o operators.o $LIBS
                 linked=yes ;;
esac

### FINAL
# error if asked to link something we didn't recognize
if [ $linked = no ]; then
  case $link in  # if the -link option makes no sense, complain 
    none) ;; # OK, do nothing
    *) echo "`basename $0`: don't know how to link $link" 1>&2 ; exit 1 ;;
  esac
fi