cppcheck/tools/readme.md

Cppcheck developer and build tools

* tools/matchcompiler.py

The matchcompiler.py is a build script that performs a few code transformations to .cpp files under the lib directory. These transformations are related to the use of Token::Match() function and are intended to improve code performance. The transformed files are saved on the build directory. This tool is silently used when building the code with SRCDIR=build, that is:

$ cd path/to/cppcheck
$ make MATCHCOMPILER=yes

Here is a simple example of the matchcompiler.py optimization. Suppose there is a file example.cpp under lib/:

// lib/example.cpp
void f1() {
    Token::Match(tok, "abc");
}

void f2() {
    const char *abc = "abc";
    Token::Match(tok, abc);
}

If you manually run matchcompiler.py from the main directory:

$ cd path/to/cppcheck
$ python tools/matchcompiler.py

A file example.cpp will be generated on the build directory:

// build/example.cpp
#include "token.h"
#include "errorlogger.h"
#include <string>
#include <cstring>
static const std::string matchStr1("abc");
// pattern: abc
static bool match1(const Token* tok) {
    if (!tok || !(tok->str()==matchStr1)/* abc */)
        return false;
    return true;
}
void f1() {
    match1(tok);
}

void f2() {
    const char *abc = "abc";
    Token::Match(tok, abc);
}

From this we can see that the usage of Token::Match() in f1() has been optimized, whereas the one in f2() couldn't be optimized (the string wasn't inline on the Token::Match() call). The developer doesn't need to use this tool during development but should be aware of these optimizations. Building with this optimization, cppcheck can get a boost of 2x of speed-up.

* tools/dmake.cpp

Automatically generates the main Makefile for Cppcheck (the main Makefile should not be modified manually). To build and run the dmake tool execute:

$ cd path/to/cppcheck
$ make dmake
$ ./dmake

* tools/reduce.py

Script that reduces code for a hang/false positive.

* tools/times.sh

Script to generate a times.log file that contains timing information of the last 20 revisions.