Splint (programming tool)

Splint, short for Secure Programming Lint, is a programming tool for statically checking C programs for security vulnerabilities and coding mistakes. Formerly called LCLint, it is a modern version of the Unix lint tool.

Splint has the ability to interpret special annotations to the source code, which gives it stronger checking than is possible just by looking at the source alone.

Splint is free software released under the terms of the GNU General Public License.

Recent development activity on Splint has slowed significantly. According to the CVS at SourceForge, as of January 2009 the most recent change in the repository was in August 2008. The whole year 2008 had only two write accesses to the repository.^[1] The maintainer has said that development is stagnant and the project needs new volunteers.^[2]

On the Splint homepage, the latest release is version 3.1.2 on July 12, 2007.

Example

#include <stdio.h>
int main()
{
    char c;
    while (c != 'x');
    {
        c = getchar();
        if (c = 'x')
            return 0;
        switch (c) {
        case '\n':
        case '\r':
            printf("Newline\n");
        default:
            printf("%c",c);
        }
    }
    return 0;
}

Splint's output:

Variable c used before definition
Suspected infinite loop.  No value used in loop test (c) is modified by test or loop body.
Assignment of int to char: c = getchar()
Test expression for if is assignment expression: c = 'x'
Test expression for if not boolean, type char: c = 'x'
Fall through case (no preceding break)

Fixed source:

#include <stdio.h>
int main()
{
    char c = (char) 0;  // Added an initial assignment definition.
 
    while (c != 'x') {
        c = (char) getchar();  // Type-cast to char.
        if (c == 'x') // Fixed the assignment error to make it a comparison operator.  
            return 0;
        switch (c) {
        case '\n':
        case '\r':
            printf("Newline\n");
            break;  // Added break statement to prevent fall-through.
        default:
            printf("%c",c);
            break;  //Added break statement to default catch, out of good practice.
        }
    }
    return 0;
}

See also

• Buffer overflow
• Memory debugger
• Software testing
• List of tools for static code analysis

References

External links

• Home page
• Publications about checking techniques
• SourceForge project page
• splint-discuss mailing list archive