Add support for X_VCPKG_BINARY_DIR environment variable

scripts/bootstrap.ps1

@@ -49,10 +49,16 @@ Write-Verbose "Examining $vcpkgRootDir for .vcpkg-root - Found"
 $Config = ConvertFrom-StringData (Get-Content "$PSScriptRoot\vcpkg-tool-metadata.txt" -Raw)
 $versionDate = $Config.VCPKG_TOOL_RELEASE_TAG
 
+if ($null -eq $env:X_VCPKG_BINARY_DIR) {
+    $vcpkgBinaryDir=$vcpkgRootDir
+} else {
+    $vcpkgBinaryDir="$env:X_VCPKG_BINARY_DIR"
+}
+
 if ($env:PROCESSOR_ARCHITECTURE -eq 'ARM64' -or $env:PROCESSOR_IDENTIFIER -match "ARMv[8,9] \(64-bit\)") {
-    & "$scriptsDir/tls12-download-arm64.exe" github.com "/microsoft/vcpkg-tool/releases/download/$versionDate/vcpkg-arm64.exe" "$vcpkgRootDir\vcpkg.exe"
+    & "$scriptsDir/tls12-download-arm64.exe" github.com "/microsoft/vcpkg-tool/releases/download/$versionDate/vcpkg-arm64.exe" "$vcpkgBinaryDir\vcpkg.exe"
 } else {
-    & "$scriptsDir/tls12-download.exe" github.com "/microsoft/vcpkg-tool/releases/download/$versionDate/vcpkg.exe" "$vcpkgRootDir\vcpkg.exe"
+    & "$scriptsDir/tls12-download.exe" github.com "/microsoft/vcpkg-tool/releases/download/$versionDate/vcpkg.exe" "$vcpkgBinaryDir\vcpkg.exe"
 }
 
 Write-Host ""
@@ -63,13 +69,13 @@ if ($LASTEXITCODE -ne 0)
     throw
 }
 
-& "$vcpkgRootDir\vcpkg.exe" version --disable-metrics
+& "$vcpkgBinaryDir\vcpkg.exe" version --disable-metrics
 
 if ($disableMetrics)
 {
-    Set-Content -Value "" -Path "$vcpkgRootDir\vcpkg.disable-metrics" -Force
+    Set-Content -Value "" -Path "$vcpkgBinaryDir\vcpkg.disable-metrics" -Force
 }
-elseif (-Not (Test-Path "$vcpkgRootDir\vcpkg.disable-metrics"))
+elseif (-Not (Test-Path "$vcpkgBinaryDir\vcpkg.disable-metrics"))
 {
     # Note that we intentionally leave any existing vcpkg.disable-metrics; once a user has
     # opted out they should stay opted out.

scripts/bootstrap.sh

@@ -54,9 +54,20 @@ if [ "$unixKernelName" = CYGWIN_NT ] || [ "$unixKernelName" = MINGW_NT ] || [ "$
     exit 0
 fi
 
+# Determine base dir to store the vcpkg executable
+if [ -z ${X_VCPKG_BINARY_DIR+x} ]; then
+    binaryDir="$vcpkgRootDir"
+else
+    binaryDir="$X_VCPKG_BINARY_DIR"
+    if [ ! -d "$X_VCPKG_BINARY_DIR" ]; then
+        echo "X_VCPKG_BINARY_DIR was set to '$X_VCPKG_BINARY_DIR', but that was not a directory."
+        exit 1
+    fi
+fi
+
 # Determine the downloads directory.
 if [ -z ${VCPKG_DOWNLOADS+x} ]; then
-    downloadsDir="$vcpkgRootDir/downloads"
+    downloadsDir="$binaryDir/downloads"
 else
     downloadsDir="$VCPKG_DOWNLOADS"
     if [ ! -d "$VCPKG_DOWNLOADS" ]; then
@@ -209,11 +220,11 @@ fi
 
 # Do the download or build.
 if [ "$vcpkgDownloadTool" = "ON" ]; then
-    vcpkgDownloadFile "https://github.com/microsoft/vcpkg-tool/releases/download/$VCPKG_TOOL_RELEASE_TAG/$vcpkgToolName" "$vcpkgRootDir/vcpkg" $vcpkgToolReleaseSha
+    vcpkgDownloadFile "https://github.com/microsoft/vcpkg-tool/releases/download/$VCPKG_TOOL_RELEASE_TAG/$vcpkgToolName" "$binaryDir/vcpkg" $vcpkgToolReleaseSha
 else
     vcpkgToolReleaseArchive="$VCPKG_TOOL_RELEASE_TAG.zip"
     vcpkgToolUrl="https://github.com/microsoft/vcpkg-tool/archive/$vcpkgToolReleaseArchive"
-    baseBuildDir="$vcpkgRootDir/buildtrees/_vcpkg"
+    baseBuildDir="$binaryDir/buildtrees/_vcpkg"
     buildDir="$baseBuildDir/build"
     archivePath="$downloadsDir/$vcpkgToolReleaseArchive"
     srcBaseDir="$baseBuildDir/src"
@@ -239,16 +250,16 @@ else
     (cd "$buildDir" && eval cmake "$srcDir" $cmakeConfigOptions) || exit 1
     (cd "$buildDir" && cmake --build .) || exit 1
 
-    rm -rf "$vcpkgRootDir/vcpkg"
-    cp "$buildDir/vcpkg" "$vcpkgRootDir/"
+    rm -rf "$binaryDir/vcpkg"
+    cp "$buildDir/vcpkg" "$binaryDir/"
 fi
 
-"$vcpkgRootDir/vcpkg" version --disable-metrics
+"$binaryDir/vcpkg" version --disable-metrics
 
 # Apply the disable-metrics marker file.
 if [ "$vcpkgDisableMetrics" = "ON" ]; then
-    touch "$vcpkgRootDir/vcpkg.disable-metrics"
-elif ! [ -f "$vcpkgRootDir/vcpkg.disable-metrics" ]; then
+    touch "$binaryDir/vcpkg.disable-metrics"
+elif ! [ -f "$binaryDir/vcpkg.disable-metrics" ]; then
     # Note that we intentionally leave any existing vcpkg.disable-metrics; once a user has
     # opted out they should stay opted out.
     cat <<EOF

scripts/buildsystems/vcpkg.cmake

@@ -463,12 +463,18 @@ endif()
 
 set(VCPKG_CMAKE_FIND_ROOT_PATH "${CMAKE_FIND_ROOT_PATH}")
 
+# by default we clobber our own source dir, but
+# this can be changed by setting X_VCPKG_BINARY_DIR
+if (NOT DEFINED ENV{X_VCPKG_BINARY_DIR})
+    set(ENV{X_VCPKG_BINARY_DIR} "${Z_VCPKG_ROOT_DIR}")
+endif()
+
 # CMAKE_EXECUTABLE_SUFFIX is not yet defined
 if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
-    set(Z_VCPKG_EXECUTABLE "${Z_VCPKG_ROOT_DIR}/vcpkg.exe")
+    set(Z_VCPKG_EXECUTABLE "$ENV{X_VCPKG_BINARY_DIR}/vcpkg.exe")
     set(Z_VCPKG_BOOTSTRAP_SCRIPT "${Z_VCPKG_ROOT_DIR}/bootstrap-vcpkg.bat")
 else()
-    set(Z_VCPKG_EXECUTABLE "${Z_VCPKG_ROOT_DIR}/vcpkg")
+    set(Z_VCPKG_EXECUTABLE "$ENV{X_VCPKG_BINARY_DIR}/vcpkg")
     set(Z_VCPKG_BOOTSTRAP_SCRIPT "${Z_VCPKG_ROOT_DIR}/bootstrap-vcpkg.sh")
 endif()