WinDDK ATL and MSVC express compatability

chrome/installer/mini_installer/mini_installer.cc

 // Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // mini_installer.exe is the first exe that is run when chrome is being
 // installed or upgraded. It is designed to be extremely small (~5KB with no
 // extra resources linked) and it has two main jobs:
 //   1) unpack the resources (possibly decompressing some)
 //   2) run the real installer (setup.exe) with appropiate flags.
 //
@@ skipping 10 matching lines @@
 // are forced to manually link against it. It comes in the form of two
 // object files that exist in $(VCInstallDir)\crt\src which are memset.obj and
 // P4_memset.obj. These two object files rely on the existence of a static
 // variable named __sse2_available which indicates the presence of intel sse2
 // extensions. We define it to false which causes a slower but safe code for
 // memcpy and memset intrinsics.
 
 // having the linker merge the sections is saving us ~500 bytes.
 #pragma comment(linker, "/MERGE:.rdata=.text")
 
+#include <intrin.h>  // __stosb for MSVC express memset implementation

[Mark Mentovai, 2011/03/17 16:45:10]

Maybe you can avoid diverging here by #including <intrin.h> to get __stosb and
then defining a static MyMemset function in this file that will be used with
both Express and non-Express. You can adjust the largeish comment above to
reflect what’s happening. This will allow you to get rid of the goofy
__sse2_availalbe hack, it may even reduce mini_installer’s size.

memset isn’t a complicated function to implement and performance isn’t
ultra-critical here so I’m a little surprised that the “link the object
files” approach was even taken in the first place.

[RN, 2011/03/17 20:15:11]

Well, __sse2_available is supposed to automatically determined by the compiler;
really rare to the user to specify it. I'm guessing that's because it was
requiring linking to both P4 and normal memset obj files.

Done.

 #include <windows.h>
 #include <setupapi.h>
 #include <shellapi.h>
 
 #include "chrome/installer/mini_installer/appid.h"
 #include "chrome/installer/mini_installer/decompress.h"
 #include "chrome/installer/mini_installer/mini_installer.h"
 #include "chrome/installer/mini_installer/mini_string.h"
 #include "chrome/installer/mini_installer/pe_resource.h"
 
@@ skipping 774 matching lines @@
 
   return exit_code;
 }
 
 }  // namespace mini_installer
 
 int MainEntryPoint() {
   int result = mini_installer::WMain(::GetModuleHandle(NULL));
   ::ExitProcess(result);
 }
+
+// VC Express editions don't come with the memset CRT obj file
+#ifdef COMPILER_MSVC_EXPRESS
+extern "C" {
+#pragma function(memset)
+  void* memset(void *dest, int ci, size_t count) {

[Mark Mentovai, 2011/03/17 16:45:10]

This and line 834 should be indented flush with the left margin. No indentation
within an extern "C" block. Instead, put a blank line between lines 829 and 830,
and another between 834 and 835 to set them off. Lines 832 and 833 should be
indented at 2 spaces.  Here’s what I’d write:

extern "C" {

#pragma function(memset)
void* memset(void *dest, int ci, size_t count) {
  __stosb((unsigned char*)dest, (unsigned char)ci, count);
  return dest;
}

}  // extern "C"

[RN, 2011/03/17 20:15:11]

OK - Done.

+      __stosb((unsigned char*)dest, (unsigned char)ci, count);
+      return dest;
+  }
+}
+#endif