Question

gcc 4.7.2
c89

Hello,

I am wondering does any one know of any tutorials or text books that cover using makefile to create some simple unit testing for my c programs.

I would like to run some automated testing that will create a test suite and add this to my Makefile.

Just want some ideas on how to get started.

Many thanks for any suggestions

Answer 1

Generating Test Function Snippets

Generating function snippets is easy with the help of gccxml and nm. The following bash script generate_snippets.sh can be called with one command line argument to generate a test function snippet for each function defined in a source file:

#!/bin/bash
#
# Generate stub functions for one file
#

# # Initialize
FILE=$1

[ ! -e "$FILE" ] && echo "file doesn't exist" && exit -1

# # Compile
OBJECT=$(mktemp)
gcc -c $FILE -o $OBJECT

# # Get Functions

# ## Get all symbols in the text sections
Y=$(mktemp)
nm $OBJECT | grep " T " | awk '{print $3;}' | sort > $Y

# ## Get functions defined in the file (including #includes)
# get all functions defined in the compilation unit of $FILE, excluding included
# dynamically linked functions

XML=$(mktemp)
X=$(mktemp)
gccxml $FILE -fxml=$XML
grep "<Function" $XML | sed 's/^.*name="\([^"]*\).*/\1/g' | sort > $X

# ## get the common lines
# This is done to get those functions which are defined in the source file and end up in
# the compiled object file.
COMMON=$(comm $Y $X -1 -2)

# # Create stubs
for func in $COMMON;
do
    cat <<_
// Test stub for $func. Returns 1 if it fails.
char test_$func() {
    return 1;
}
_

done

# # Clean up

rm $OBJECT $XML $X $Y

TODOS

The script is not yet perfect. You should probably include a test to only generate test functions for those functions which aren’t tested yet. As this is done analogous to finding the common names between $X and $Y, I leave this as an exercise. When this is implemented, it makes sense to run this script from a Makefile. See the other answer for pointers on that.

Example Usage

Consider the C file hello.c:

#include <stdio.h>

int foo();
int bar();

int main() {
    printf("hello, world\n");
    return 0;
}


int foo() {
    printf("nothing\n");
    return 1;
}

int bar() {
    printf("still nothing\n");
    return 1;
}

Running the script above with this file as input yields the following output:

// Test stub for bar. Returns 1 if it fails.
char test_bar() {
    return 1;
}
// Test stub for foo. Returns 1 if it fails.
char test_foo() {
    return 1;
}
// Test stub for main. Returns 1 if it fails.
char test_main() {
    return 1;
}

Just put those snippets into the appropriate file and fill them with logic as needed. After that, compile the test suite and run it.