Let 'pear build' work on windows for building pecl extensions.

A few notes:
Currently only supports release builds, and of course, requires msdev!
pecl packages must have package.xml and xxx.dsp files for this to work
the package name in package.xml must match the name of the dsp file, so
package iisfunc must have dsp iisfunc.dsp

pear/PEAR/Builder.php

@@ -37,6 +37,9 @@ class PEAR_Builder extends PEAR_Common
 
     var $current_callback = null;
 
+    // used for msdev builds
+    var $_lastline = null;
+    var $_firstline = null;
     // }}}
     // {{{ constructor
 
@@ -54,6 +57,99 @@ class PEAR_Builder extends PEAR_Common
     }
 
     // }}}
+    
+    // {{{ _build_win32()
+
+    /**
+     * Build an extension from source on windows.
+     * requires msdev
+     */
+    function _build_win32($descfile, $callback = null)
+    {
+        if (PEAR::isError($info = $this->infoFromDescriptionFile($descfile))) {
+            return $info;
+        }
+        $dir = dirname($descfile);
+        $old_cwd = getcwd();
+
+        if (!@chdir($dir)) {
+            return $this->raiseError("could not chdir to $dir");
+        }
+        $this->log(2, "building in $dir");
+
+        $dsp = $info['package'].'.dsp';
+        if (!@is_file("$dir/$dsp")) {
+            return $this->raiseError("The DSP $dsp does not exist.");
+        }
+        // XXX TODO: make release build type configurable
+        $command = 'msdev '.$dsp.' /MAKE "'.$info['package']. ' - Release"';
+        
+        $this->current_callback = $callback;
+        $err = $this->_runCommand($command, array(&$this, 'msdevCallback'));
+        if (PEAR::isError($err)) {
+            return $err;
+        }
+        
+        // figure out the build platform and type
+        $platform = 'Win32';
+        $buildtype = 'Release';
+        if (preg_match('/.*?'.$info['package'].'\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+("'.
+                    $info['package'].'\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 $dsp.");
+        }
+        if (@copy($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 $built_files;
+    }
+    // }}}
+    
+    // {{{ msdevCallback()
+    function msdevCallback($what, $data)
+    {
+        if (!$this->_firstline)
+            $this->_firstline = $data;
+        $this->_lastline = $data;
+    }
+    // }}}
+    
     // {{{ build()
 
     /**
@@ -81,6 +177,9 @@ class PEAR_Builder extends PEAR_Common
      */
     function build($descfile, $callback = null)
     {
+        if (PEAR_OS == "Windows") {
+            return $this->_build_win32($descfile,$callback);
+        }
         if (PEAR_OS != 'Unix') {
             return $this->raiseError("building extensions not supported on this platform");
         }