appveyor: Use Ninja/sccache on MSVC

Now that the final bug fixes have been merged into sccache we can start
leveraging sccache on the MSVC builders on AppVeyor instead of relying on the
ad-hoc caching strategy of trigger files and whatnot.

3 files changed, 92 insertions, 9 deletions

diff --git a/src/bootstrap/Cargo.toml b/src/bootstrap/Cargo.toml
index ecfddec328c..1088067c2de 100644
--- a/src/bootstrap/Cargo.toml
+++ b/src/bootstrap/Cargo.toml
@@ -23,6 +23,11 @@ name = "rustdoc"
 path = "bin/rustdoc.rs"
 test = false
 
+[[bin]]
+name = "sccache-plus-cl"
+path = "bin/sccache-plus-cl.rs"
+test = false
+
 [dependencies]
 build_helper = { path = "../build_helper" }
 cmake = "0.1.17"
diff --git a/src/bootstrap/bin/sccache-plus-cl.rs b/src/bootstrap/bin/sccache-plus-cl.rs
new file mode 100644
index 00000000000..cf0c1274923
--- /dev/null
+++ b/src/bootstrap/bin/sccache-plus-cl.rs
@@ -0,0 +1,43 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+extern crate gcc;
+
+use std::env;
+use std::process::{self, Command};
+
+fn main() {
+    let target = env::var("SCCACHE_TARGET").unwrap();
+    // Locate the actual compiler that we're invoking
+    env::remove_var("CC");
+    env::remove_var("CXX");
+    let mut cfg = gcc::Config::new();
+    cfg.cargo_metadata(false)
+       .out_dir("/")
+       .target(&target)
+       .host(&target)
+       .opt_level(0)
+       .debug(false);
+    let compiler = cfg.get_compiler();
+
+    // Invoke sccache with said compiler
+    let sccache_path = env::var_os("SCCACHE_PATH").unwrap();
+    let mut cmd = Command::new(&sccache_path);
+    cmd.arg(compiler.path());
+    for &(ref k, ref v) in compiler.env() {
+        cmd.env(k, v);
+    }
+    for arg in env::args().skip(1) {
+        cmd.arg(arg);
+    }
+
+    let status = cmd.status().expect("failed to spawn");
+    process::exit(status.code().unwrap_or(2))
+}
diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs
index c0b8a9f1ef6..3d87f701b2a 100644
--- a/src/bootstrap/native.rs
+++ b/src/bootstrap/native.rs
@@ -19,6 +19,7 @@
 //! ensure that they're always in place if needed.
 
 use std::env;
+use std::ffi::OsString;
 use std::fs::{self, File};
 use std::io::{Read, Write};
 use std::path::Path;
@@ -129,22 +130,56 @@ pub fn llvm(build: &Build, target: &str) {
            .define("LLVM_TABLEGEN", &host);
     }
 
-    // MSVC handles compiler business itself
-    if !target.contains("msvc") {
-        if let Some(ref ccache) = build.config.ccache {
+    let sanitize_cc = |cc: &Path| {
+        if target.contains("msvc") {
+            OsString::from(cc.to_str().unwrap().replace("\\", "/"))
+        } else {
+            cc.as_os_str().to_owned()
+        }
+    };
+
+    let configure_compilers = |cfg: &mut cmake::Config| {
+        // MSVC with CMake uses msbuild by default which doesn't respect these
+        // vars that we'd otherwise configure. In that case we just skip this
+        // entirely.
+        if target.contains("msvc") && !build.config.ninja {
+            return
+        }
+
+        let cc = build.cc(target);
+        let cxx = build.cxx(target);
+
+        // Handle msvc + ninja + ccache specially (this is what the bots use)
+        if target.contains("msvc") &&
+           build.config.ninja &&
+           build.config.ccache.is_some() {
+            let mut cc = env::current_exe().expect("failed to get cwd");
+            cc.set_file_name("sccache-plus-cl.exe");
+
+           cfg.define("CMAKE_C_COMPILER", sanitize_cc(&cc))
+              .define("CMAKE_CXX_COMPILER", sanitize_cc(&cc));
+           cfg.env("SCCACHE_PATH",
+                   build.config.ccache.as_ref().unwrap())
+              .env("SCCACHE_TARGET", target);
+
+        // If ccache is configured we inform the build a little differently hwo
+        // to invoke ccache while also invoking our compilers.
+        } else if let Some(ref ccache) = build.config.ccache {
            cfg.define("CMAKE_C_COMPILER", ccache)
-              .define("CMAKE_C_COMPILER_ARG1", build.cc(target))
+              .define("CMAKE_C_COMPILER_ARG1", sanitize_cc(cc))
               .define("CMAKE_CXX_COMPILER", ccache)
-              .define("CMAKE_CXX_COMPILER_ARG1", build.cxx(target));
+              .define("CMAKE_CXX_COMPILER_ARG1", sanitize_cc(cxx));
         } else {
-           cfg.define("CMAKE_C_COMPILER", build.cc(target))
-              .define("CMAKE_CXX_COMPILER", build.cxx(target));
+           cfg.define("CMAKE_C_COMPILER", sanitize_cc(cc))
+              .define("CMAKE_CXX_COMPILER", sanitize_cc(cxx));
         }
-        cfg.build_arg("-j").build_arg(build.jobs().to_string());
 
+        cfg.build_arg("-j").build_arg(build.jobs().to_string());
         cfg.define("CMAKE_C_FLAGS", build.cflags(target).join(" "));
         cfg.define("CMAKE_CXX_FLAGS", build.cflags(target).join(" "));
-    }
+    };
+
+    configure_compilers(&mut cfg);
 
     if env::var_os("SCCACHE_ERROR_LOG").is_some() {
         cfg.env("RUST_LOG", "sccache=info");