Description
Before the lab you should re-read the relevant lecture slides and their accompanying examples.
Create a new directory for this lab called lab09, change to this directory, and fetch the provided code for this week by running these commands:
$ mkdir lab09
$ cd lab09
$ 2041 fetch lab09
Or, if you’re not working on CSE, you can download the provided code as a zip file or a tar file.
A Makefile is a useful tool for documenting dependencies among components, as well as ensuring that executable components are up-to-date relative to their source code.
While in general automatically extract all dependencies for complex software systems, a tool that generate most of a Makefile can be very useful.
Your task in this exercise is to write a Perl script makemake.pl which generates an appropriate Makefile for a multi-file C program.
This will require making a number of assumptions.
Your task
Write a Perl script makemake.pl to generate a Makefile that will build the C program whose source code is in the current directory.
The script takes no arguments, and writes the Makefile text to its standard output.
Assumptions
The current directory contains all code files from only one C program.
The C program is composed only of .c and .h files.
Exactly one .c file will contain a main() function.
The main() function appears on a line that matches the regexp
/^\s*(int|void)\s*main\s*\(/
No other line in the files matches this regex.
The executable is named after the file containing the main() function (without the .c)
Any line starting with #include is a genuine include line
(ignore multi-line comments and other preprocessor commands like #if)
All the dependencies that need to be included in the Makefile involve files that exist in the current directory
Example Output
Three example C programs are available as a zip file
Here is the output your program should produce for each of these examples:
| $ unzip /web/cs2041/20T2/activities/makemake/examples.zip Archive: examples.zip creating: easy/ extracting: easy/graphics.h inflating: easy/graphics.c ….
$ cd easy $ ls easymain.c graphics.c graphics.h world.c world.h $ ../makemake.pl >Makefile $ cat Makefile
CC = gcc CFLAGS = -Wall -g easymain: easymain.o graphics.o world.o
graphics.o: graphics.h world.h graphics.c easymain.o: world.h graphics.h easymain.c world.o: world.h world.c $ make gcc -Wall -g -c -o easymain.o easymain.c gcc -Wall -g -c -o graphics.o graphics.c gcc -Wall -g -c -o world.o world.c gcc -o easymain easymain.o graphics.o world.o $ cd ../medium $ ls a.c a.h aaa.c aaa.h b.c b.h bb.c bb.h c.c c.h common.h main.c $ ../makemake.pl >Makefile $ cat Makefile
CC = gcc CFLAGS = -Wall -g main: a.o aaa.o b.o bb.o c.o main.o $(CC) $(CFLAGS) -o $@ a.o aaa.o b.o bb.o c.o main.o b.o: b.h bb.h aaa.h b.c c.o: c.h c.c a.o: common.h a.h a.c bb.o: bb.h aaa.h bb.c main.o: a.h c.h b.h bb.h aaa.h main.c $ make gcc -Wall -g -c -o a.o a.c gcc -Wall -g -c -o aaa.o aaa.c gcc -Wall -g -c -o b.o b.c gcc -Wall -g -c -o bb.o bb.c gcc -Wall -g -c -o c.o c.c gcc -Wall -g -c -o main.o main.c gcc -o main a.o aaa.o b.o bb.o c.o main.o $ cd ../hard $ ls circ1.c circ1.h circ2.c circ2.h circmain.c $ ../makemake.pl >Makefile $ cat Makefile
CC = gcc CFLAGS = -Wall -g circmain: circ1.o circ2.o circmain.o
circ1.o: circ1.h circ2.h circ1.c circmain.o: circ1.h circ2.h circmain.c circ2.o: circ2.h circ1.h circ2.c $ make gcc -Wall -g -c -o circ1.o circ1.c |
gcc -Wall -g -c -o circ2.o circ2.c gcc -Wall -g -c -o circmain.o circmain.c gcc -o circmain circ1.o circ2.o circmain.o
Further Requirements
You should include four standard lines at the front of every Makefile
# Makefile generated at timestamp in format given above
CC = gcc
CFLAGS = -Wall -g
There should be a blank line immediately before each Make rule
Hints
You could use a hash to represent all dependencies
The Perl expression `date` will generate a suitable timestamp
The Perl builtin glob is an easy way to get a list of the .c or .h files in the current directory
You do not need to produce rules for dependencies on standard .h files (e.g. stdio.h) You can assumes includes of standard libraries use <…> notation, e.g:
#include $lt;stdio.h>
When you think your program is working, you can use autotest to run some simple automated tests:
Write a Perl regex which matches unary number iff it is composite (not prime).
In other words write a regex that matches a string of n ones iff n is composite.
A test program is provide to assist you in doing this:
Download test_regex_prime.pl, or copy it to your CSE account using the following command:
$ cp -n /web/cs2041/20T2/activities/regex_prime/test_regex_prime.pl .
For example to test the regex ^1(11)+1$ against the integers 2 to 12, you can run
| $ chmod 755 test_regex_prime.pl
$ test_regex_prime.pl 2 12 ‘^1(11)+1$’ 2 = 11 unary – prime 3 = 111 unary – prime 4 = 1111 unary – composite 5 = 11111 unary – prime 6 = 111111 unary – composite 7 = 1111111 unary – prime 8 = 11111111 unary – composite 9 = 111111111 unary – prime 10 = 1111111111 unary – composite 11 = 11111111111 unary – prime 12 = 111111111111 unary – composite |
Put your solution in regex_prime.txt, for example:
$ test_regex_prime.pl 40 50 “$(cat regex_prime.txt)”
- = 1111111111111111111111111111111111111111 unary – composite
- = 11111111111111111111111111111111111111111 unary – prime
- = 111111111111111111111111111111111111111111 unary – composite
- = 1111111111111111111111111111111111111111111 unary – prime
- = 11111111111111111111111111111111111111111111 unary – composite
- = 111111111111111111111111111111111111111111111 unary – composite
- = 1111111111111111111111111111111111111111111111 unary – composite
- = 11111111111111111111111111111111111111111111111 unary – prime
- = 111111111111111111111111111111111111111111111111 unary – composite
- = 1111111111111111111111111111111111111111111111111 unary – composite
- = 11111111111111111111111111111111111111111111111111 unary – composite
Your regex must be less than 80 characters.
Hint: you can’t do this with a true regular expression, i.e using |*() alone, you need to use features that Perl adds.
Don’t google for other people solutions – see if you can come up with your own
