Autodetect VS 2019

Author: Zoxc

src/windows_registry.rs

@@ -217,6 +217,34 @@ mod impl_ {
         }
     }
 
+    fn vs16_instance() -> Option<PathBuf> {
+        vs15_instances()?.find_map(|instance| {
+            let instance = instance.ok()?;
+            let installation_name = instance.installation_name().ok()?;;
+            if installation_name.to_str()?.starts_with("VisualStudio/16.") {
+                Some(PathBuf::from(instance.installation_path().ok()?))
+            } else {
+                None
+            }
+        })
+    }
+
+    fn find_tool_in_vs16_path(tool: &str, target: &str) -> Option<Tool> {
+        let path = vs16_instance()?.join(tool);
+        if !path.is_file() {
+            return None;
+        }
+        let mut tool = Tool::new(path);
+        if target.contains("x86_64") {
+            tool.env.push(("Platform".into(), "X64".into()));
+        }
+        Some(tool)
+    }
+
+    fn find_msbuild_vs16(target: &str) -> Option<Tool> {
+        find_tool_in_vs16_path(r"MSBuild\Current\Bin\MSBuild.exe", target)
+    }
+
     // In MSVC 15 (2017) MS once again changed the scheme for locating
     // the tooling.  Now we must go through some COM interfaces, which
     // is super fun for Rust.
@@ -662,6 +690,10 @@ mod impl_ {
 
     pub fn has_msbuild_version(version: &str) -> bool {
         match version {
+            "16.0" => {
+                find_msbuild_vs16("x86_64-pc-windows-msvc").is_some()
+                    || find_msbuild_vs16("i686-pc-windows-msvc").is_some()
+            }
             "15.0" => {
                 find_msbuild_vs15("x86_64-pc-windows-msvc").is_some()
                     || find_msbuild_vs15("i686-pc-windows-msvc").is_some()