src/PEAR/Builder.php
function _build_win32($descfile, $callback = null)
    {
        if (is_object($descfile)) {
            $pkg = $descfile;
            $descfile = $pkg->getPackageFile();
        } else {
            $pf = &new PEAR_PackageFile($this->config, $this->debug);
            $pkg = &$pf->fromPackageFile($descfile, PEAR_VALIDATE_NORMAL);
            if (PEAR::isError($pkg)) {
                return $pkg;
            }
        }
        $dir = dirname($descfile);
        $old_cwd = getcwd();

        if (!file_exists($dir) || !is_dir($dir) || !chdir($dir)) {
            return $this->raiseError("could not chdir to $dir");
        }

        // packages that were in a .tar have the packagefile in this directory
        $vdir = $pkg->getPackage() . '-' . $pkg->getVersion();
        if (file_exists($dir) && is_dir($vdir)) {
            if (!chdir($vdir)) {
                return $this->raiseError("could not chdir to " . realpath($vdir));
            }

            $dir = getcwd();
        }

        $this->log(2, "building in $dir");

        $dsp = $pkg->getPackage().'.dsp';
        if (!file_exists("$dir/$dsp")) {
            return $this->raiseError("The DSP $dsp does not exist.");
        }
        // XXX TODO: make release build type configurable
        $command = 'msdev '.$dsp.' /MAKE "'.$pkg->getPackage(). ' - Release"';

        $err = $this->_runCommand($command, array(&$this, 'msdevCallback'));
        if (PEAR::isError($err)) {
            return $err;
        }

        // figure out the build platform and type
        $platform = 'Win32';
        $buildtype = 'Release';
        if (preg_match('/.*?'.$pkg->getPackage().'\s-\s(\w+)\s(.*?)-+/i',$this->_firstline,$matches)) {
            $platform = $matches[1];
            $buildtype = $matches[2];
        }

        if (preg_match('/(.*)?\s-\s(\d+).*?(\d+)/', $this->_lastline, $matches)) {
            if ($matches[2]) {
                // there were errors in the build
                return $this->raiseError("There were errors during compilation.");
            }
            $out = $matches[1];
        } else {
            return $this->raiseError("Did not understand the completion status returned from msdev.exe.");
        }

        // msdev doesn't tell us the output directory :/
        // open the dsp, find /out and use that directory
        $dsptext = join(file($dsp),'');

        // this regex depends on the build platform and type having been
        // correctly identified above.
        $regex ='/.*?!IF\s+"\$\(CFG\)"\s+==\s+("'.
                    $pkg->getPackage().'\s-\s'.
                    $platform.'\s'.
                    $buildtype.'").*?'.
                    '\/out:"(.*?)"/is';

        if ($dsptext && preg_match($regex, $dsptext, $matches)) {
            // what we get back is a relative path to the output file itself.
            $outfile = realpath($matches[2]);
        } else {
            return $this->raiseError("Could not retrieve output information from $dsp.");
        }
        // realpath returns false if the file doesn't exist
        if ($outfile && copy($outfile, "$dir/$out")) {
            $outfile = "$dir/$out";
        }

        $built_files[] = array(
            'file' => "$outfile",
            'php_api' => $this->php_api_version,
            'zend_mod_api' => $this->zend_module_api_no,
            'zend_ext_api' => $this->zend_extension_api_no,
            );

        return $built_files;
    }
function _build_win32($descfile, $callback = null)
    {
        if (is_object($descfile)) {
            $pkg = $descfile;
            $descfile = $pkg->getPackageFile();
        } else {
            $pf = &new PEAR_PackageFile($this->config, $this->debug);
            $pkg = &$pf->fromPackageFile($descfile, PEAR_VALIDATE_NORMAL);
            if (PEAR::isError($pkg)) {
                return $pkg;
            }
        }
        $dir = dirname($descfile);
        $old_cwd = getcwd();

        if (!file_exists($dir) || !is_dir($dir) || !chdir($dir)) {
            return $this->raiseError("could not chdir to $dir");
        }

        // packages that were in a .tar have the packagefile in this directory
        $vdir = $pkg->getPackage() . '-' . $pkg->getVersion();
        if (file_exists($dir) && is_dir($vdir)) {
            if (!chdir($vdir)) {
                return $this->raiseError("could not chdir to " . realpath($vdir));
            }

            $dir = getcwd();
        }

        $this->log(2, "building in $dir");

        $dsp = $pkg->getPackage().'.dsp';
        if (!file_exists("$dir/$dsp")) {
            return $this->raiseError("The DSP $dsp does not exist.");
        }
        // XXX TODO: make release build type configurable
        $command = 'msdev '.$dsp.' /MAKE "'.$pkg->getPackage(). ' - Release"';

        $err = $this->_runCommand($command, array(&$this, 'msdevCallback'));
        if (PEAR::isError($err)) {
            return $err;
        }

        // figure out the build platform and type
        $platform = 'Win32';
        $buildtype = 'Release';
        if (preg_match('/.*?'.$pkg->getPackage().'\s-\s(\w+)\s(.*?)-+/i',$this->_firstline,$matches)) {
            $platform = $matches[1];
            $buildtype = $matches[2];
        }

        if (preg_match('/(.*)?\s-\s(\d+).*?(\d+)/', $this->_lastline, $matches)) {
            if ($matches[2]) {
                // there were errors in the build
                return $this->raiseError("There were errors during compilation.");
            }
            $out = $matches[1];
        } else {
            return $this->raiseError("Did not understand the completion status returned from msdev.exe.");
        }

        // msdev doesn't tell us the output directory :/
        // open the dsp, find /out and use that directory
        $dsptext = join(file($dsp),'');

        // this regex depends on the build platform and type having been
        // correctly identified above.
        $regex ='/.*?!IF\s+"\$\(CFG\)"\s+==\s+("'.
                    $pkg->getPackage().'\s-\s'.
                    $platform.'\s'.
                    $buildtype.'").*?'.
                    '\/out:"(.*?)"/is';

        if ($dsptext && preg_match($regex, $dsptext, $matches)) {
            // what we get back is a relative path to the output file itself.
            $outfile = realpath($matches[2]);
        } else {
            return $this->raiseError("Could not retrieve output information from $dsp.");
        }
        // realpath returns false if the file doesn't exist
        if ($outfile && copy($outfile, "$dir/$out")) {
            $outfile = "$dir/$out";
        }

        $built_files[] = array(
            'file' => "$outfile",
            'php_api' => $this->php_api_version,
            'zend_mod_api' => $this->zend_module_api_no,
            'zend_ext_api' => $this->zend_extension_api_no,
            );

        return $built_files;
    }
Build an extension from source on windows.
requires msdev