PhpBrew\Extension\ExtensionFactory::createPeclExtension PHP Method

    public static function createPeclExtension($packageName, $packageXmlPath)
    {
        $parser = new PackageXmlParser();
        $package = $parser->parse($packageXmlPath);
        $ext = new PeclExtension($packageName);
        $ext->setPackage($package);
        /*
         * xhprof stores package.xml in the root directory, but putting the
         * config.m4 in the extension directory.
         * the path can be retrieve from the contents part from the package.xml
         */
        if ($m4path = $ext->findConfigM4FileFromPackageXml()) {
            $sourceDirectory = dirname($packageXmlPath);
            $m4dir = dirname($m4path);
            if ($m4dir != '.') {
                $sourceDirectory .= DIRECTORY_SEPARATOR . $m4dir;
            }
            $ext->setSourceDirectory($sourceDirectory);
        } else {
            $ext->setSourceDirectory(dirname($packageXmlPath));
        }
        return $ext;
    }