From 6670b87c18c544bbc9fa167f583b27dc52bce3d9 Mon Sep 17 00:00:00 2001
From: Robert Schumacher <roschuma@microsoft.com>
Date: Sat, 10 Mar 2018 14:19:07 -0800
Subject: [PATCH] [vcpkg] Add VCPKG_DEFAULT_VS_PATH environment variable

---
 toolsrc/include/vcpkg/vcpkgpaths.h | 4 +++-
 toolsrc/src/vcpkg.cpp              | 4 +++-
 toolsrc/src/vcpkg/vcpkgpaths.cpp   | 9 +++++++--
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/toolsrc/include/vcpkg/vcpkgpaths.h b/toolsrc/include/vcpkg/vcpkgpaths.h
index 84e8110ec9c..71f1bbba98a 100644
--- a/toolsrc/include/vcpkg/vcpkgpaths.h
+++ b/toolsrc/include/vcpkg/vcpkgpaths.h
@@ -33,7 +33,7 @@ namespace vcpkg
 
     struct VcpkgPaths
     {
-        static Expected<VcpkgPaths> create(const fs::path& vcpkg_root_dir);
+        static Expected<VcpkgPaths> create(const fs::path& vcpkg_root_dir, const std::string& default_vs_path);
 
         fs::path package_dir(const PackageSpec& spec) const;
         fs::path port_dir(const PackageSpec& spec) const;
@@ -90,5 +90,7 @@ namespace vcpkg
         Lazy<fs::path> ifw_repogen_exe;
         Lazy<std::vector<Toolset>> toolsets;
         Lazy<std::vector<Toolset>> toolsets_vs2013;
+
+        fs::path default_vs_path;
     };
 }
diff --git a/toolsrc/src/vcpkg.cpp b/toolsrc/src/vcpkg.cpp
index ef68e6f7236..d9b91536701 100644
--- a/toolsrc/src/vcpkg.cpp
+++ b/toolsrc/src/vcpkg.cpp
@@ -94,7 +94,9 @@ static void inner(const VcpkgCmdArguments& args)
 
     Checks::check_exit(VCPKG_LINE_INFO, !vcpkg_root_dir.empty(), "Error: Could not detect vcpkg-root.");
 
-    const Expected<VcpkgPaths> expected_paths = VcpkgPaths::create(vcpkg_root_dir);
+    auto default_vs_path = System::get_environment_variable("VCPKG_DEFAULT_VS_PATH").value_or("");
+
+    const Expected<VcpkgPaths> expected_paths = VcpkgPaths::create(vcpkg_root_dir, default_vs_path);
     Checks::check_exit(VCPKG_LINE_INFO,
                        !expected_paths.error(),
                        "Error: Invalid vcpkg root directory %s: %s",
diff --git a/toolsrc/src/vcpkg/vcpkgpaths.cpp b/toolsrc/src/vcpkg/vcpkgpaths.cpp
index e62ef866263..02bc5f04129 100644
--- a/toolsrc/src/vcpkg/vcpkgpaths.cpp
+++ b/toolsrc/src/vcpkg/vcpkgpaths.cpp
@@ -293,7 +293,7 @@ namespace vcpkg
         return fetch_tool(paths.scripts, "installerbase", TOOL_DATA);
     }
 
-    Expected<VcpkgPaths> VcpkgPaths::create(const fs::path& vcpkg_root_dir)
+    Expected<VcpkgPaths> VcpkgPaths::create(const fs::path& vcpkg_root_dir, const std::string& default_vs_path)
     {
         std::error_code ec;
         const fs::path canonical_vcpkg_root_dir = fs::stdfs::canonical(vcpkg_root_dir, ec);
@@ -304,6 +304,7 @@ namespace vcpkg
 
         VcpkgPaths paths;
         paths.root = canonical_vcpkg_root_dir;
+        paths.default_vs_path = default_vs_path;
 
         if (paths.root.empty())
         {
@@ -643,7 +644,11 @@ namespace vcpkg
 
         std::vector<const Toolset*> candidates = Util::element_pointers(vs_toolsets);
         const auto tsv = prebuildinfo.platform_toolset.get();
-        const auto vsp = prebuildinfo.visual_studio_path.get();
+        auto vsp = prebuildinfo.visual_studio_path.get();
+        if (!vsp && !default_vs_path.empty())
+        {
+            vsp = &default_vs_path;
+        }
 
         if (tsv && vsp)
         {