# The program "make" looks for a file called "Makefile" or "makefile" in
# the current directory.  It will not find the file if it is called "MAKEFILE"
# or "Makefile.txt"

# Any line beginning with a `#' sign is a comment and will be
# ignored by the "make" command.
# Choose the compiler. (There are others!)
CC = gcc

# List our usual flags. These ones make the compiler very careful.
CFLAGS = -pipe -ansi -pedantic -Wall -Wpointer-arith -Wcast-qual \
-Wcast-align -Wwrite-strings -Wconversion -Wstrict-prototypes \
-Wmissing-prototypes

# We need to include the mathematical library if we want to use "sqrt",
# for example. We might want other libraries too, and in that case we
# would add them here.
LIBS =  -lm

# To run a debugger, we want to compile with the "-g" flag set.
# The first line below defines the debugging flag. The second sets
# "NEWFLAGS" to contain the debugging flag if the user's command line is:
# make DEBUG=TRUE
# (instead of just plain "make" as usual). And the third line below
# adds NEWFLAGS to the end of the standard list of flags.

DEBUGFLAGS = -g
NEWFLAGS = $(DEBUG:TRUE=$(DEBUGFLAGS))
CFLAGS += $(NEWFLAGS)

# Within a makefile, you can ask "make" to call practically any Unix command.
# Ordinarily the command itself is displayed before it is executed, but if
# you begin the line in the makefile with "@", the command is not displayed.
# These lines cause "make" to display its flag settings if it is called without
# any arguments.

@echo "Flag settings with options as called:"
@echo DEBUGFLAGS=$(DEBUGFLAGS)
@echo NEWFLAGS=$(NEWFLAGS)
@echo CFLAGS=$(CFLAGS)

# The next entry lets us compile all the executables at once.
# If "make" seems not to be doing anything, the output files are presumably
# up to date already. To see them all being compiled, just remove the
# executable files and call make again.

all: hello careful math

hello : hello.c
	$(CC) $(CFLAGS) -o hello hello.c
	chmod 755 hello

# The "chmod" line makes it so that you can use the executable file
# "hello". If the line were left out, I could use it but not you.
# Notice that all the commands to construct "hello" are on lines
# following the line "hello : ". And notice that the commands ARE
# ALL INDENTED BY ONE TAB STOP. No tab, no work!

careful : careful.c
	$(CC) $(CFLAGS) -o careful careful.c
	chmod 755 careful

math: math.c
	$(CC) $(CFLAGS) -o math math.c $(LIBS)
	chmod 755 math

# This entry lets us use "make clean" to get rid of junk files.
clean:
	rm -f a.out core *.o