Copy local CRT DLLs to gn output directories

build/vs_toolchain.py

Index: build/vs_toolchain.py
diff --git a/build/vs_toolchain.py b/build/vs_toolchain.py
index ddff24a43882a3f35eaffeb637a1be2b2a0b3785..35d99da0bc1a830db7d20f61764238451e3a40ac 100755
--- a/build/vs_toolchain.py
+++ b/build/vs_toolchain.py
@@ -8,6 +8,7 @@ import json
 import os
 import pipes
 import shutil
+import stat
 import subprocess
 import sys
 
@@ -74,6 +75,16 @@ def SetEnvironmentAndGetRuntimeDllDirs():
       os.environ['GYP_MSVS_OVERRIDE_PATH'] = DetectVisualStudioPath()
     if not 'GYP_MSVS_VERSION' in os.environ:
       os.environ['GYP_MSVS_VERSION'] = GetVisualStudioVersion()
+    # When using an installed toolchain these files aren't needed in the output
+    # directory in order to run binaries locally, but they are needed in order
+    # to create isolates or the mini_installer. Copying them to the output
+    # directory ensures that they are available when needed.
+    if os.access('C:/Windows/SysWOW64', os.F_OK):
+      # Default 64-bit and 32-bit system directories on 64-bit Windows.
+      vs_runtime_dll_dirs = [ 'C:/Windows/System32', 'C:/Windows/SysWOW64' ]

[scottmg, 2016/05/31 21:57:44]

Hmm, I'm confused. I would have thought it was x86, x64.

But looking below at CopyVsRuntimeDlls() I see it's x86,x64, but CopyDlls() is
x64,x86! Do you know what's going on?

[brucedawson, 2016/05/31 23:32:18]

I'm not sure. That's worrisome that gyp and gn behave differently.

While investigating I found that the behavior is also different depending on
whether you are running 64-bit python or not. Sigh...

+    else:
+      # Default 32-bit system directories on 32-bit Windows.
+      vs_runtime_dll_dirs = [ None, 'C:/Windows/System32' ]
 
   return vs_runtime_dll_dirs
 
@@ -164,8 +175,12 @@ def _CopyRuntimeImpl(target, source, verbose=True):
     if verbose:
       print 'Copying %s to %s...' % (source, target)
     if os.path.exists(target):
+      # Make the file writable so that we can delete it now.
+      os.chmod(target, stat.S_IWRITE)
       os.unlink(target)
     shutil.copy2(source, target)
+    # Make the file writable so that we can overwrite or delete it later.
+    os.chmod(target, stat.S_IWRITE)
 
 
 def _CopyRuntime2013(target_dir, source_dir, dll_pattern):
@@ -186,8 +201,16 @@ def _CopyRuntime2015(target_dir, source_dir, dll_pattern, suffix):
     target = os.path.join(target_dir, dll)
     source = os.path.join(source_dir, dll)
     _CopyRuntimeImpl(target, source)
-  ucrt_src_dir = os.path.join(source_dir, 'api-ms-win-*.dll')
-  for ucrt_src_file in glob.glob(ucrt_src_dir):
+  # OS installs of Visual Studio (and all installs of Windows 10) put the
+  # universal CRT files in c:\Windows\System32\downlevel - look for them there
+  # to support DEPOT_TOOLS_WIN_TOOLCHAIN=0.
+  if os.path.exists(os.path.join(source_dir, 'downlevel')):
+    ucrt_src_dir = os.path.join(source_dir, 'downlevel', 'api-ms-win-*.dll')

[scottmg, 2016/05/31 21:57:44]

Maybe ucrt_src_pattern or _glob instead.

[brucedawson, 2016/05/31 23:32:18]

Done.

+  else:
+    ucrt_src_dir = os.path.join(source_dir, 'api-ms-win-*.dll')
+  ucrt_files = glob.glob(ucrt_src_dir)
+  assert len(ucrt_files) > 0
+  for ucrt_src_file in ucrt_files:
     file_part = os.path.basename(ucrt_src_file)
     ucrt_dst_file = os.path.join(target_dir, file_part)
     _CopyRuntimeImpl(ucrt_dst_file, ucrt_src_file, False)