path: root/www-client/firefox/files/firefox-60.0-update-cc-to-honor-CC.patch

https://bugzilla.mozilla.org/show_bug.cgi?id=1496270
https://bugzilla.mozilla.org/show_bug.cgi?id=1445528

--- a/third_party/rust/cc/.cargo-checksum.json
+++ b/third_party/rust/cc/.cargo-checksum.json
@@ -1 +1 @@
-{"files":{".travis.yml":"1a4a3f7f90349924378e93acbb524b9127e37c02cfbc6dc59fd904bbdc1c8d0b","Cargo.toml":"623dd06a83bcbf2f292ab51af93e9b79b689e3be06a62968b79f4e36f1bb769f","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"378f5840b258e2779c39418f3f2d7b2ba96f1c7917dd6be0713f88305dbda397","README.md":"186c5c8a62520cb7a3d90d77161c954b52ae8456fca0e0669bc3a5b889592a43","appveyor.yml":"ab45bfdcf2596f357225a54e730c34d518a8f3ad56c2ed33af682cfd45bddc02","src/bin/gcc-shim.rs":"d6be9137cb48b86891e7b263adbf492e1193ffe682db9ba4a88eb1079b874b58","src/com.rs":"0cb06f5db0fb70d27db0e5917ca337de6e7032119e6aabfea1bad9c719f5f34b","src/lib.rs":"996b650e19d5ccd6e64e741789427017c913644e980862a7286ec4ed53c14a17","src/registry.rs":"3876ef9573e3bbc050aef41a684b9a510cc1a91b15ae874fe032cf4377b4d116","src/setup_config.rs":"1a3eeb11c6847c31f2a4685b62ab35c76f0b6d5a17f7ed99e9df164283a771f7","src/winapi.rs":"cb5e6cab3eb570b0f97c660ca448ccfb5024262c0c7b245c181daad91a79f211","src/windows_registry.rs":"6de548aa94215e449f0e58e9a3b1702939d7c2f7b63a9040901c948bf138201d","tests/cc_env.rs":"7402315eea7ffa23b29b393c1de8e236294ede9de562ff0a562704a157135341","tests/support/mod.rs":"092551f9f6e3a999fa0aa02f93314aac0bda2b09268f948c423df56a43575e0b","tests/test.rs":"b1164258714e13173f3861126e97bedf1e29aa24618993c4eb0edd57c431dcc7"},"package":"deaf9ec656256bb25b404c51ef50097207b9cbb29c933d31f92cae5a8a0ffee0"}
\ No newline at end of file
+{"files":{".travis.yml":"1a4a3f7f90349924378e93acbb524b9127e37c02cfbc6dc59fd904bbdc1c8d0b","Cargo.toml":"623dd06a83bcbf2f292ab51af93e9b79b689e3be06a62968b79f4e36f1bb769f","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"378f5840b258e2779c39418f3f2d7b2ba96f1c7917dd6be0713f88305dbda397","README.md":"186c5c8a62520cb7a3d90d77161c954b52ae8456fca0e0669bc3a5b889592a43","appveyor.yml":"ab45bfdcf2596f357225a54e730c34d518a8f3ad56c2ed33af682cfd45bddc02","src/bin/gcc-shim.rs":"d6be9137cb48b86891e7b263adbf492e1193ffe682db9ba4a88eb1079b874b58","src/com.rs":"0cb06f5db0fb70d27db0e5917ca337de6e7032119e6aabfea1bad9c719f5f34b","src/lib.rs":"6e8cea99f5fc8e5982b1ea9a336ee2f9a6158a9498c8f0c36f1e8cee8c99716e","src/registry.rs":"3876ef9573e3bbc050aef41a684b9a510cc1a91b15ae874fe032cf4377b4d116","src/setup_config.rs":"1a3eeb11c6847c31f2a4685b62ab35c76f0b6d5a17f7ed99e9df164283a771f7","src/winapi.rs":"cb5e6cab3eb570b0f97c660ca448ccfb5024262c0c7b245c181daad91a79f211","src/windows_registry.rs":"6de548aa94215e449f0e58e9a3b1702939d7c2f7b63a9040901c948bf138201d","tests/cc_env.rs":"7402315eea7ffa23b29b393c1de8e236294ede9de562ff0a562704a157135341","tests/support/mod.rs":"092551f9f6e3a999fa0aa02f93314aac0bda2b09268f948c423df56a43575e0b","tests/test.rs":"b1164258714e13173f3861126e97bedf1e29aa24618993c4eb0edd57c431dcc7"},"package":"deaf9ec656256bb25b404c51ef50097207b9cbb29c933d31f92cae5a8a0ffee0"}
\ No newline at end of file
--- a/third_party/rust/cc/src/lib.rs
+++ b/third_party/rust/cc/src/lib.rs
@@ -61,15 +61,14 @@
 extern crate rayon;
 
 use std::env;
-use std::ffi::{OsString, OsStr};
+use std::ffi::{OsStr, OsString};
 use std::fs;
-use std::path::{PathBuf, Path};
-use std::process::{Command, Stdio, Child};
-use std::io::{self, BufReader, BufRead, Read, Write};
+use std::path::{Path, PathBuf};
+use std::process::{Child, Command, Stdio};
+use std::io::{self, BufRead, BufReader, Read, Write};
 use std::thread::{self, JoinHandle};
-
-#[cfg(feature = "parallel")]
-use std::sync::Mutex;
+use std::collections::HashMap;
+use std::sync::{Arc, Mutex};
 
 // These modules are all glue to support reading the MSVC version from
 // the registry and from COM interfaces
@@ -97,6 +96,7 @@ pub struct Build {
     objects: Vec<PathBuf>,
     flags: Vec<String>,
     flags_supported: Vec<String>,
+    known_flag_support_status: Arc<Mutex<HashMap<String, bool>>>,
     files: Vec<PathBuf>,
     cpp: bool,
     cpp_link_stdlib: Option<Option<String>>,
@@ -241,8 +241,7 @@ impl ToolFamily {
     fn nvcc_debug_flag(&self) -> &'static str {
         match *self {
             ToolFamily::Msvc => unimplemented!(),
-            ToolFamily::Gnu |
-            ToolFamily::Clang => "-G",
+            ToolFamily::Gnu | ToolFamily::Clang => "-G",
         }
     }
 
@@ -251,8 +250,7 @@ impl ToolFamily {
     fn nvcc_redirect_flag(&self) -> &'static str {
         match *self {
             ToolFamily::Msvc => unimplemented!(),
-            ToolFamily::Gnu |
-            ToolFamily::Clang => "-Xcompiler",
+            ToolFamily::Gnu | ToolFamily::Clang => "-Xcompiler",
         }
     }
 }
@@ -269,10 +267,7 @@ struct Object {
 impl Object {
     /// Create a new source file -> object file pair.
     fn new(src: PathBuf, dst: PathBuf) -> Object {
-        Object {
-            src: src,
-            dst: dst,
-        }
+        Object { src: src, dst: dst }
     }
 }
 
@@ -289,6 +284,7 @@ impl Build {
             objects: Vec::new(),
             flags: Vec::new(),
             flags_supported: Vec::new(),
+            known_flag_support_status: Arc::new(Mutex::new(HashMap::new())),
             files: Vec::new(),
             shared_flag: None,
             static_flag: None,
@@ -344,10 +340,8 @@ impl Build {
     ///     .compile("foo");
     /// ```
     pub fn define<'a, V: Into<Option<&'a str>>>(&mut self, var: &str, val: V) -> &mut Build {
-        self.definitions.push((
-            var.to_string(),
-            val.into().map(|s| s.to_string()),
-        ));
+        self.definitions
+            .push((var.to_string(), val.into().map(|s| s.to_string())));
         self
     }
 
@@ -398,7 +392,16 @@ impl Build {
     ///
     /// It may return error if it's unable to run the compilier with a test file
     /// (e.g. the compiler is missing or a write to the `out_dir` failed).
+    ///
+    /// Note: Once computed, the result of this call is stored in the
+    /// `known_flag_support` field. If `is_flag_supported(flag)`
+    /// is called again, the result will be read from the hash table.
     pub fn is_flag_supported(&self, flag: &str) -> Result<bool, Error> {
+        let mut known_status = self.known_flag_support_status.lock().unwrap();
+        if let Some(is_supported) = known_status.get(flag).cloned() {
+            return Ok(is_supported);
+        }
+
         let out_dir = self.get_out_dir()?;
         let src = self.ensure_check_file()?;
         let obj = out_dir.join("flag_check");
@@ -413,7 +416,8 @@ impl Build {
             .cuda(self.cuda);
         let compiler = cfg.try_get_compiler()?;
         let mut cmd = compiler.to_command();
-        command_add_output_file(&mut cmd, &obj, target.contains("msvc"), false);
+        let is_arm = target.contains("aarch64") || target.contains("arm");
+        command_add_output_file(&mut cmd, &obj, target.contains("msvc"), false, is_arm);
 
         // We need to explicitly tell msvc not to link and create an exe
         // in the root directory of the crate
@@ -424,7 +428,10 @@ impl Build {
         cmd.arg(&src);
 
         let output = cmd.output()?;
-        Ok(output.stderr.is_empty())
+        let is_supported = output.stderr.is_empty();
+
+        known_status.insert(flag.to_owned(), is_supported);
+        Ok(is_supported)
     }
 
     /// Add an arbitrary flag to the invocation of the compiler if it supports it
@@ -777,9 +784,8 @@ impl Build {
         A: AsRef<OsStr>,
         B: AsRef<OsStr>,
     {
-        self.env.push(
-            (a.as_ref().to_owned(), b.as_ref().to_owned()),
-        );
+        self.env
+            .push((a.as_ref().to_owned(), b.as_ref().to_owned()));
         self
     }
 
@@ -880,31 +886,19 @@ impl Build {
     fn compile_objects(&self, objs: &[Object]) -> Result<(), Error> {
         use self::rayon::prelude::*;
 
-        let mut cfg = rayon::Configuration::new();
         if let Ok(amt) = env::var("NUM_JOBS") {
             if let Ok(amt) = amt.parse() {
-                cfg = cfg.num_threads(amt);
+                let _ = rayon::ThreadPoolBuilder::new()
+                    .num_threads(amt)
+                    .build_global();
             }
         }
-        drop(rayon::initialize(cfg));
-
-        let results: Mutex<Vec<Result<(), Error>>> = Mutex::new(Vec::new());
-
-        objs.par_iter().with_max_len(1).for_each(
-            |obj| {
-                let res = self.compile_object(obj);
-                results.lock().unwrap().push(res)
-            },
-        );
 
         // Check for any errors and return the first one found.
-        for result in results.into_inner().unwrap().iter() {
-            if result.is_err() {
-                return result.clone();
-            }
-        }
-
-        Ok(())
+        objs.par_iter()
+            .with_max_len(1)
+            .map(|obj| self.compile_object(obj))
+            .collect()
     }
 
     #[cfg(not(feature = "parallel"))]
@@ -917,7 +911,8 @@ impl Build {
 
     fn compile_object(&self, obj: &Object) -> Result<(), Error> {
         let is_asm = obj.src.extension().and_then(|s| s.to_str()) == Some("asm");
-        let msvc = self.get_target()?.contains("msvc");
+        let target = self.get_target()?;
+        let msvc = target.contains("msvc");
         let (mut cmd, name) = if msvc && is_asm {
             self.msvc_macro_assembler()?
         } else {
@@ -931,15 +926,17 @@ impl Build {
                 compiler
                     .path
                     .file_name()
-                    .ok_or_else(|| {
-                        Error::new(ErrorKind::IOError, "Failed to get compiler path.")
-                    })?
+                    .ok_or_else(|| Error::new(ErrorKind::IOError, "Failed to get compiler path."))?
                     .to_string_lossy()
                     .into_owned(),
             )
         };
-        command_add_output_file(&mut cmd, &obj.dst, msvc, is_asm);
-        cmd.arg(if msvc { "/c" } else { "-c" });
+        let is_arm = target.contains("aarch64") || target.contains("arm");
+        command_add_output_file(&mut cmd, &obj.dst, msvc, is_asm, is_arm);
+        // armasm and armasm64 don't requrie -c option
+        if !msvc || !is_asm || !is_arm {
+            cmd.arg(if msvc { "/c" } else { "-c" });
+        }
         cmd.arg(&obj.src);
 
         run(&mut cmd, &name)?;
@@ -967,9 +964,7 @@ impl Build {
         let name = compiler
             .path
             .file_name()
-            .ok_or_else(|| {
-                Error::new(ErrorKind::IOError, "Failed to get compiler path.")
-            })?
+            .ok_or_else(|| Error::new(ErrorKind::IOError, "Failed to get compiler path."))?
             .to_string_lossy()
             .into_owned();
 
@@ -1054,8 +1049,8 @@ impl Build {
                 cmd.args.push(crt_flag.into());
 
                 match &opt_level[..] {
-                    "z" | "s" => cmd.args.push("/Os".into()),
-                    "1" => cmd.args.push("/O1".into()),
+                    // Msvc uses /O1 to enable all optimizations that minimize code size.
+                    "z" | "s" | "1" => cmd.args.push("/O1".into()),
                     // -O3 is a valid value for gcc and clang compilers, but not msvc. Cap to /O2.
                     "2" | "3" => cmd.args.push("/O2".into()),
                     _ => {}
@@ -1070,8 +1065,10 @@ impl Build {
                     cmd.args.push(format!("-O{}", opt_level).into());
                 }
 
-                cmd.push_cc_arg("-ffunction-sections".into());
-                cmd.push_cc_arg("-fdata-sections".into());
+                if !target.contains("-ios") {
+                    cmd.push_cc_arg("-ffunction-sections".into());
+                    cmd.push_cc_arg("-fdata-sections".into());
+                }
                 if self.pic.unwrap_or(!target.contains("windows-gnu")) {
                     cmd.push_cc_arg("-fPIC".into());
                 }
@@ -1169,7 +1166,7 @@ impl Build {
                 // linker that we're generating 32-bit executables as well. This'll
                 // typically only be used for build scripts which transitively use
                 // these flags that try to compile executables.
-                if target == "i686-unknown-linux-musl" {
+                if target == "i686-unknown-linux-musl" || target == "i586-unknown-linux-musl" {
                     cmd.args.push("-Wl,-melf_i386".into());
                 }
 
@@ -1212,14 +1209,13 @@ impl Build {
         if self.cpp {
             match (self.cpp_set_stdlib.as_ref(), cmd.family) {
                 (None, _) => {}
-                (Some(stdlib), ToolFamily::Gnu) |
-                (Some(stdlib), ToolFamily::Clang) => {
+                (Some(stdlib), ToolFamily::Gnu) | (Some(stdlib), ToolFamily::Clang) => {
                     cmd.push_cc_arg(format!("-stdlib=lib{}", stdlib).into());
                 }
                 _ => {
                     println!(
                         "cargo:warning=cpp_set_stdlib is specified, but the {:?} compiler \
-                              does not support this option, ignored",
+                         does not support this option, ignored",
                         cmd.family
                     );
                 }
@@ -1272,6 +1268,10 @@ impl Build {
         let target = self.get_target()?;
         let tool = if target.contains("x86_64") {
             "ml64.exe"
+        } else if target.contains("arm") {
+            "armasm.exe"
+        } else if target.contains("aarch64") {
+            "armasm64.exe"
         } else {
             "ml.exe"
         };
@@ -1307,20 +1307,55 @@ impl Build {
         if target.contains("msvc") {
             let mut cmd = match self.archiver {
                 Some(ref s) => self.cmd(s),
-                None => {
-                    windows_registry::find(&target, "lib.exe").unwrap_or_else(
-                        || {
-                            self.cmd("lib.exe")
-                        },
-                    )
-                }
+                None => windows_registry::find(&target, "lib.exe")
+                    .unwrap_or_else(|| self.cmd("lib.exe")),
             };
+
             let mut out = OsString::from("/OUT:");
             out.push(dst);
-            run(
-                cmd.arg(out).arg("/nologo").args(&objects).args(&self.objects),
-                "lib.exe",
-            )?;
+            cmd.arg(out).arg("/nologo");
+
+            // Similar to https://github.com/rust-lang/rust/pull/47507
+            // and https://github.com/rust-lang/rust/pull/48548
+            let estimated_command_line_len = objects
+                .iter()
+                .chain(&self.objects)
+                .map(|a| a.as_os_str().len())
+                .sum::<usize>();
+            if estimated_command_line_len > 1024 * 6 {
+                let mut args = String::from("\u{FEFF}"); // BOM
+                for arg in objects.iter().chain(&self.objects) {
+                    args.push('"');
+                    for c in arg.to_str().unwrap().chars() {
+                        if c == '"' {
+                            args.push('\\')
+                        }
+                        args.push(c)
+                    }
+                    args.push('"');
+                    args.push('\n');
+                }
+
+                let mut utf16le = Vec::new();
+                for code_unit in args.encode_utf16() {
+                    utf16le.push(code_unit as u8);
+                    utf16le.push((code_unit >> 8) as u8);
+                }
+
+                let mut args_file = OsString::from(dst);
+                args_file.push(".args");
+                fs::File::create(&args_file)
+                    .unwrap()
+                    .write_all(&utf16le)
+                    .unwrap();
+
+                let mut args_file_arg = OsString::from("@");
+                args_file_arg.push(args_file);
+                cmd.arg(args_file_arg);
+            } else {
+                cmd.args(&objects).args(&self.objects);
+            }
+            run(&mut cmd, "lib.exe")?;
 
             // The Rust compiler will look for libfoo.a and foo.lib, but the
             // MSVC linker will also be passed foo.lib, so be sure that both
@@ -1412,6 +1447,18 @@ impl Build {
 
         cmd.args.push("-isysroot".into());
         cmd.args.push(sdk_path.trim().into());
+        cmd.args.push("-fembed-bitcode".into());
+        /*
+         * TODO we probably ultimatedly want the -fembed-bitcode-marker flag
+         * but can't have it now because of an issue in LLVM:
+         * https://github.com/alexcrichton/cc-rs/issues/301
+         * https://github.com/rust-lang/rust/pull/48896#comment-372192660
+         */
+        /*
+        if self.get_opt_level()? == "0" {
+            cmd.args.push("-fembed-bitcode-marker".into());
+        }
+        */
 
         Ok(())
     }
@@ -1437,37 +1484,44 @@ impl Build {
         };
 
         // On Solaris, c++/cc unlikely to exist or be correct.
-        let default = if host.contains("solaris") { gnu } else { traditional };
-
-        let tool_opt: Option<Tool> =
-            self.env_tool(env)
-                .map(|(tool, cc, args)| {
-                    let mut t = Tool::new(PathBuf::from(tool));
-                    if let Some(cc) = cc {
-                        t.cc_wrapper_path = Some(PathBuf::from(cc));
-                    }
-                    for arg in args {
-                        t.cc_wrapper_args.push(arg.into());
-                    }
-                    t
-                })
-                .or_else(|| {
-                    if target.contains("emscripten") {
-                        let tool = if self.cpp { "em++" } else { "emcc" };
-                        // Windows uses bat file so we have to be a bit more specific
-                        if cfg!(windows) {
-                            let mut t = Tool::new(PathBuf::from("cmd"));
-                            t.args.push("/c".into());
-                            t.args.push(format!("{}.bat", tool).into());
-                            Some(t)
-                        } else {
-                            Some(Tool::new(PathBuf::from(tool)))
-                        }
+        let default = if host.contains("solaris") {
+            gnu
+        } else {
+            traditional
+        };
+
+        let tool_opt: Option<Tool> = self.env_tool(env)
+            .map(|(tool, cc, args)| {
+                // chop off leading/trailing whitespace to work around
+                // semi-buggy build scripts which are shared in
+                // makefiles/configure scripts (where spaces are far more
+                // lenient)
+                let mut t = Tool::new(PathBuf::from(tool.trim()));
+                if let Some(cc) = cc {
+                    t.cc_wrapper_path = Some(PathBuf::from(cc));
+                }
+                for arg in args {
+                    t.cc_wrapper_args.push(arg.into());
+                }
+                t
+            })
+            .or_else(|| {
+                if target.contains("emscripten") {
+                    let tool = if self.cpp { "em++" } else { "emcc" };
+                    // Windows uses bat file so we have to be a bit more specific
+                    if cfg!(windows) {
+                        let mut t = Tool::new(PathBuf::from("cmd"));
+                        t.args.push("/c".into());
+                        t.args.push(format!("{}.bat", tool).into());
+                        Some(t)
                     } else {
-                        None
+                        Some(Tool::new(PathBuf::from(tool)))
                     }
-                })
-                .or_else(|| windows_registry::find_tool(&target, "cl.exe"));
+                } else {
+                    None
+                }
+            })
+            .or_else(|| windows_registry::find_tool(&target, "cl.exe"));
 
         let tool = match tool_opt {
             Some(t) => t,
@@ -1501,6 +1555,7 @@ impl Build {
                         "armv7-unknown-linux-gnueabihf" => Some("arm-linux-gnueabihf"),
                         "armv7-unknown-linux-musleabihf" => Some("arm-linux-musleabihf"),
                         "armv7-unknown-netbsd-eabihf" => Some("armv7--netbsdelf-eabihf"),
+                        "i586-unknown-linux-musl" => Some("musl"),
                         "i686-pc-windows-gnu" => Some("i686-w64-mingw32"),
                         "i686-unknown-linux-musl" => Some("musl"),
                         "i686-unknown-netbsd" => Some("i486--netbsdelf"),
@@ -1509,10 +1564,12 @@ impl Build {
                         "mips64-unknown-linux-gnuabi64" => Some("mips64-linux-gnuabi64"),
                         "mips64el-unknown-linux-gnuabi64" => Some("mips64el-linux-gnuabi64"),
                         "powerpc-unknown-linux-gnu" => Some("powerpc-linux-gnu"),
+                        "powerpc-unknown-linux-gnuspe" => Some("powerpc-linux-gnuspe"),
                         "powerpc-unknown-netbsd" => Some("powerpc--netbsd"),
                         "powerpc64-unknown-linux-gnu" => Some("powerpc-linux-gnu"),
                         "powerpc64le-unknown-linux-gnu" => Some("powerpc64le-linux-gnu"),
                         "s390x-unknown-linux-gnu" => Some("s390x-linux-gnu"),
+                        "sparc-unknown-linux-gnu" => Some("sparc-linux-gnu"),
                         "sparc64-unknown-linux-gnu" => Some("sparc64-linux-gnu"),
                         "sparc64-unknown-netbsd" => Some("sparc64--netbsd"),
                         "sparcv9-sun-solaris" => Some("sparcv9-sun-solaris"),
@@ -1538,14 +1595,18 @@ impl Build {
         };
 
         let tool = if self.cuda {
-            assert!(tool.args.is_empty(),
-                "CUDA compilation currently assumes empty pre-existing args");
+            assert!(
+                tool.args.is_empty(),
+                "CUDA compilation currently assumes empty pre-existing args"
+            );
             let nvcc = match self.get_var("NVCC") {
                 Err(_) => "nvcc".into(),
                 Ok(nvcc) => nvcc,
             };
             let mut nvcc_tool = Tool::with_features(PathBuf::from(nvcc), self.cuda);
-            nvcc_tool.args.push(format!("-ccbin={}", tool.path.display()).into());
+            nvcc_tool
+                .args
+                .push(format!("-ccbin={}", tool.path.display()).into());
             nvcc_tool
         } else {
             tool
@@ -1568,10 +1629,7 @@ impl Build {
             Some(res) => Ok(res),
             None => Err(Error::new(
                 ErrorKind::EnvVarNotFound,
-                &format!(
-                    "Could not find environment variable {}.",
-                    var_base
-                ),
+                &format!("Could not find environment variable {}.", var_base),
             )),
         }
     }
@@ -1585,21 +1643,68 @@ impl Build {
             .collect()
     }
 
-
     /// Returns compiler path, optional modifier name from whitelist, and arguments vec
     fn env_tool(&self, name: &str) -> Option<(String, Option<String>, Vec<String>)> {
-        self.get_var(name).ok().map(|tool| {
-            let whitelist = ["ccache", "distcc", "sccache"];
+        let tool = match self.get_var(name) {
+            Ok(tool) => tool,
+            Err(_) => return None,
+        };
 
-            for t in whitelist.iter() {
-                if tool.starts_with(t) && tool[t.len()..].starts_with(' ')  {
-                    let args = tool.split_whitespace().collect::<Vec<_>>();
+        // If this is an exact path on the filesystem we don't want to do any
+        // interpretation at all, just pass it on through. This'll hopefully get
+        // us to support spaces-in-paths.
+        if Path::new(&tool).exists() {
+            return Some((tool, None, Vec::new()));
+        }
+
+        // Ok now we want to handle a couple of scenarios. We'll assume from
+        // here on out that spaces are splitting separate arguments. Two major
+        // features we want to support are:
+        //
+        //      CC='sccache cc'
+        //
+        // aka using `sccache` or any other wrapper/caching-like-thing for
+        // compilations. We want to know what the actual compiler is still,
+        // though, because our `Tool` API support introspection of it to see
+        // what compiler is in use.
+        //
+        // additionally we want to support
+        //
+        //      CC='cc -flag'
+        //
+        // where the CC env var is used to also pass default flags to the C
+        // compiler.
+        //
+        // It's true that everything here is a bit of a pain, but apparently if
+        // you're not literally make or bash then you get a lot of bug reports.
+        let known_wrappers = ["ccache", "distcc", "sccache", "icecc"];
+
+        let mut parts = tool.split_whitespace();
+        let maybe_wrapper = match parts.next() {
+            Some(s) => s,
+            None => return None,
+        };
 
-                    return (args[1].to_string(), Some(t.to_string()), args[2..].iter().map(|s| s.to_string()).collect());
-                }
+        let file_stem = Path::new(maybe_wrapper)
+            .file_stem()
+            .unwrap()
+            .to_str()
+            .unwrap();
+        if known_wrappers.contains(&file_stem) {
+            if let Some(compiler) = parts.next() {
+                return Some((
+                    compiler.to_string(),
+                    Some(maybe_wrapper.to_string()),
+                    parts.map(|s| s.to_string()).collect(),
+                ));
             }
-            (tool, None, Vec::new())
-        })
+        }
+
+        Some((
+            maybe_wrapper.to_string(),
+            None,
+            parts.map(|s| s.to_string()).collect(),
+        ))
     }
 
     /// Returns the default C++ standard library for the current target: `libc++`
@@ -1611,7 +1716,7 @@ impl Build {
                 let target = self.get_target()?;
                 if target.contains("msvc") {
                     Ok(None)
-                } else if target.contains("darwin") {
+                } else if target.contains("apple") {
                     Ok(Some("c++".to_string()))
                 } else if target.contains("freebsd") {
                     Ok(Some("c++".to_string()))
@@ -1700,10 +1805,7 @@ impl Build {
             Some(s) => Ok(s),
             None => Err(Error::new(
                 ErrorKind::EnvVarNotFound,
-                &format!(
-                    "Environment variable {} not defined.",
-                    v.to_string()
-                ),
+                &format!("Environment variable {} not defined.", v.to_string()),
             )),
         }
     }
@@ -1731,8 +1833,9 @@ impl Tool {
         let family = if let Some(fname) = path.file_name().and_then(|p| p.to_str()) {
             if fname.contains("clang") {
                 ToolFamily::Clang
-            } else if fname.contains("cl") && !fname.contains("cloudabi") &&
-                      !fname.contains("uclibc") {
+            } else if fname.contains("cl") && !fname.contains("cloudabi")
+                && !fname.contains("uclibc")
+            {
                 ToolFamily::Msvc
             } else {
                 ToolFamily::Gnu
@@ -1775,8 +1878,8 @@ impl Tool {
                 cmd.arg(&self.path);
                 cmd.args(&self.cc_wrapper_args);
                 cmd
-            },
-            None => Command::new(&self.path)
+            }
+            None => Command::new(&self.path),
         };
         cmd.args(&self.args);
         for &(ref k, ref v) in self.env.iter() {
@@ -1822,10 +1925,8 @@ impl Tool {
                     cc_env.push(arg);
                 }
                 cc_env
-            },
-            None => {
-                OsString::from("")
             }
+            None => OsString::from(""),
         }
     }
 
@@ -1868,8 +1969,7 @@ fn run(cmd: &mut Command, program: &str) -> Result<(), Error> {
                 ErrorKind::ToolExecError,
                 &format!(
                     "Failed to wait on spawned child process, command {:?} with args {:?}.",
-                    cmd,
-                    program
+                    cmd, program
                 ),
             ))
         }
@@ -1884,9 +1984,7 @@ fn run(cmd: &mut Command, program: &str) -> Result<(), Error> {
             ErrorKind::ToolExecError,
             &format!(
                 "Command {:?} with args {:?} did not execute successfully (status code {}).",
-                cmd,
-                program,
-                status
+                cmd, program, status
             ),
         ))
     }
@@ -1909,8 +2007,7 @@ fn run_output(cmd: &mut Command, program: &str) -> Result<Vec<u8>, Error> {
                 ErrorKind::ToolExecError,
                 &format!(
                     "Failed to wait on spawned child process, command {:?} with args {:?}.",
-                    cmd,
-                    program
+                    cmd, program
                 ),
             ))
         }
@@ -1925,9 +2022,7 @@ fn run_output(cmd: &mut Command, program: &str) -> Result<Vec<u8>, Error> {
             ErrorKind::ToolExecError,
             &format!(
                 "Command {:?} with args {:?} did not execute successfully (status code {}).",
-                cmd,
-                program,
-                status
+                cmd, program, status
             ),
         ))
     }
@@ -1943,39 +2038,30 @@ fn spawn(cmd: &mut Command, program: &str) -> Result<(Child, JoinHandle<()>), Er
     match cmd.stderr(Stdio::piped()).spawn() {
         Ok(mut child) => {
             let stderr = BufReader::new(child.stderr.take().unwrap());
-            let print = thread::spawn(move || for line in stderr.split(b'\n').filter_map(
-                |l| l.ok(),
-            )
-            {
-                print!("cargo:warning=");
-                std::io::stdout().write_all(&line).unwrap();
-                println!("");
+            let print = thread::spawn(move || {
+                for line in stderr.split(b'\n').filter_map(|l| l.ok()) {
+                    print!("cargo:warning=");
+                    std::io::stdout().write_all(&line).unwrap();
+                    println!("");
+                }
             });
             Ok((child, print))
         }
         Err(ref e) if e.kind() == io::ErrorKind::NotFound => {
             let extra = if cfg!(windows) {
                 " (see https://github.com/alexcrichton/cc-rs#compile-time-requirements \
-                   for help)"
+                 for help)"
             } else {
                 ""
             };
             Err(Error::new(
                 ErrorKind::ToolNotFound,
-                &format!(
-                    "Failed to find tool. Is `{}` installed?{}",
-                    program,
-                    extra
-                ),
+                &format!("Failed to find tool. Is `{}` installed?{}", program, extra),
             ))
         }
         Err(_) => Err(Error::new(
             ErrorKind::ToolExecError,
-            &format!(
-                "Command {:?} with args {:?} failed to start.",
-                cmd,
-                program
-            ),
+            &format!("Command {:?} with args {:?} failed to start.", cmd, program),
         )),
     }
 }
@@ -1984,9 +2070,10 @@ fn fail(s: &str) -> ! {
     panic!("\n\nInternal error occurred: {}\n\n", s)
 }
 
-
-fn command_add_output_file(cmd: &mut Command, dst: &Path, msvc: bool, is_asm: bool) {
-    if msvc && is_asm {
+fn command_add_output_file(cmd: &mut Command, dst: &Path, msvc: bool, is_asm: bool, is_arm: bool) {
+    if msvc && is_asm && is_arm {
+        cmd.arg("-o").arg(&dst);
+    } else if msvc && is_asm {
         cmd.arg("/Fo").arg(dst);
     } else if msvc {
         let mut s = OsString::from("/Fo");