browser(webkit): copy MS VC++ redistributable libs from VS installation (#4360)

Author: yury-s

browser_patches/buildbots/README.md

@@ -120,19 +120,6 @@ The `core.longpaths` is needed for webkit since it has some very long layout pat
 
 Run `c:\mozilla-build\start-shell.bat` and checkout Playwright repo to `/c/playwright`.
 
-### 7. Create a c:\WEBKIT_WIN64_LIBS\ directory with win64 dlls
-
-
-Create a new `c:\WEBKIT_WIN64_LIBS` folder and copy the following libraries from `C:\Windows\System32` into it:
-- `msvcp140.dll`
-- `msvcp140_2.dll`
-- `vcruntime140.dll`
-- `vcruntime140_1.dll`
-
-> **NOTE**: these libraries are expected by `//browser_patches/webkit/archive.sh`. 
-
-This is necessary since mingw is a 32-bit application and cannot access the `C:\Windows\System32` folder due to [Windows FileSystem Redirector](https://docs.microsoft.com/en-us/windows/win32/winprog64/file-system-redirector?redirectedfrom=MSDN). ([StackOverflow question](https://stackoverflow.com/questions/18982551/is-mingw-caching-windows-directory-contents)) 
-
 ## Running Build Loop
 
 1. Launch `c:\mozilla-build/start-shell.bat`

browser_patches/firefox/build.sh

@@ -26,19 +26,19 @@ elif [[ "$(uname)" == "Linux" ]]; then
   echo "-- building on Linux"
   echo "ac_add_options --disable-av1" > .mozconfig
 elif [[ "$(uname)" == MINGW* ]]; then
-  TMPFILE=$(mktemp)
+  DLL_FILE=""
   if [[ $1 == "--win64" ]]; then
     echo "-- building win64 build on MINGW"
     echo "ac_add_options --target=x86_64-pc-mingw32" > .mozconfig
     echo "ac_add_options --host=x86_64-pc-mingw32" >> .mozconfig
-    "$PROGRAMFILES\Microsoft Visual Studio\Installer\vswhere.exe" -latest -find '**\Redist\MSVC\*\x64\**\vcruntime140.dll' > $TMPFILE
+    DLL_FILE=$("$PROGRAMFILES\Microsoft Visual Studio\Installer\vswhere.exe" -latest -find '**\Redist\MSVC\*\x64\**\vcruntime140.dll')
   else
     echo "-- building win32 build on MINGW"
-    "$PROGRAMFILES\Microsoft Visual Studio\Installer\vswhere.exe" -latest -find '**\Redist\MSVC\*\x86\**\vcruntime140.dll' > $TMPFILE
+    DLL_FILE=$("$PROGRAMFILES\Microsoft Visual Studio\Installer\vswhere.exe" -latest -find '**\Redist\MSVC\*\x86\**\vcruntime140.dll')
   fi
-  WIN32_REDIST_DIR=$(dirname "$(cat $TMPFILE)")
+  WIN32_REDIST_DIR=$(dirname "$DLL_FILE")
   if ! [[ -d $WIN32_REDIST_DIR ]]; then
-    echo "Error: cannot find MS VS C++ redistributable $WIN32_REDIST_DIR"
+    echo "ERROR: cannot find MS VS C++ redistributable $WIN32_REDIST_DIR"
     exit 1;
   fi
   echo "export WIN32_REDIST_DIR=\"$WIN32_REDIST_DIR\"" >> .mozconfig

browser_patches/webkit/archive.sh

@@ -71,6 +71,17 @@ createZipForLinux() {
   rm -rf $tmpdir
 }
 
+# see https://docs.microsoft.com/en-us/visualstudio/install/tools-for-managing-visual-studio-instances?view=vs-2019
+printMSVCRedistDir() {
+  local dll_file=$("$PROGRAMFILES\Microsoft Visual Studio\Installer\vswhere.exe" -latest -find '**\Redist\MSVC\*\x64\**\vcruntime140.dll')
+  local redist_dir=$(dirname "$dll_file")
+  if ! [[ -d $redist_dir ]]; then
+    echo "ERROR: cannot find MS VS C++ redistributable $redist_dir"
+    exit 1;
+  fi
+  echo "$redist_dir"
+}
+
 createZipForWindows() {
   # create a TMP directory to copy all necessary files
   local tmpdir="/tmp/webkit-deploy-$(date +%s)"
@@ -82,7 +93,7 @@ createZipForWindows() {
   cp -t $tmpdir JavaScriptCore.dll PlaywrightLib.dll WTF.dll WebKit2.dll libEGL.dll libGLESv2.dll
   cp -t $tmpdir Playwright.exe WebKitNetworkProcess.exe WebKitWebProcess.exe
   cd -
-  cd /c/WEBKIT_WIN64_LIBS
+  cd "$(printMSVCRedistDir)"
   cp -t $tmpdir msvcp140.dll vcruntime140.dll vcruntime140_1.dll msvcp140_2.dll
   cd -