per target rustflags

"backport" of rust-lang/cargo#3157

Author: Jorge Aparicio

Diff for: CHANGELOG.md

@@ -5,6 +5,11 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Added
+
+- Xargo now supports per-target rustflags: `target.thumbv7em-none-eabihf.rustflags` in
+  .cargo/config.
+
 ## [v0.1.11] - 2016-09-30
 
 ### Fixed

Diff for: src/main.rs

@@ -21,6 +21,7 @@ use std::{env, fs, mem};
 use cargo::core::shell::{ColorConfig, Verbosity};
 use cargo::util::{self, CargoResult, ChainError, Config, Filesystem};
 use rustc_cfg::Cfg;
+use rustc_version::Channel;
 
 mod sysroot;
 
@@ -47,26 +48,35 @@ fn run(config_opt: &mut Option<Config>) -> CargoResult<()> {
                          is not set")
         }));
 
+    let meta = rustc_version::version_meta_for(&config.rustc_info().verbose_version);
+    if meta.channel != Channel::Nightly {
+        return Err(util::human("Only the nightly channel is currently supported"));
+    }
+
     let (mut cargo, target, verbose, is_cargo_doc, verb) = try!(parse_args());
 
-    let rustflags = &try!(rustflags(config));
+    let target = if let Some(target) = target {
+        Some(target)
+    } else {
+        if let Some(triple) = try!(config.get_string("build.target")) {
+            try!(Target::from(&triple.val))
+        } else {
+            None
+        }
+    };
+
+    let rustflags = &try!(rustflags(config, target.as_ref().map(|t| &t.triple), &meta.host));
     let profiles = &try!(parse_cargo_toml(config));
     let mut with_sysroot = false;
 
     match verb.as_ref().map(|s| &**s) {
         // All these commands shouldn't trigger a sysroot rebuild
-        Some("clean") | Some("new") | Some("init") | Some("update") | Some("search") => {},
+        Some("clean") | Some("new") | Some("init") | Some("update") | Some("search") => {}
         _ => {
             if let Some(target) = target {
-                try!(sysroot::create(config, &target, root, verbose, rustflags, profiles));
+                try!(sysroot::create(config, &target, root, verbose, rustflags, profiles, meta));
                 with_sysroot = true;
-            } else if let Some(triple) = try!(config.get_string("build.target")) {
-                if let Some(target) = try!(Target::from(&triple.val)) {
-                    try!(sysroot::create(config, &target, root, verbose, rustflags, profiles));
-                    with_sysroot = true;
-                }
             }
-
         }
     }
 
@@ -201,13 +211,20 @@ fn parse_args() -> CargoResult<(Command, Option<Target>, bool, bool, Option<Stri
 
 /// Returns the RUSTFLAGS the user has set either via the env variable or via build.rustflags
 // NOTE Logic copied from cargo's Context::rustflags_args
-fn rustflags(config: &Config) -> CargoResult<Vec<String>> {
+fn rustflags(config: &Config, target: Option<&String>, host: &String) -> CargoResult<Vec<String>> {
     // First try RUSTFLAGS from the environment
     if let Some(a) = env::var("RUSTFLAGS").ok() {
         let args = a.split(" ").map(str::trim).filter(|s| !s.is_empty()).map(str::to_string);
         return Ok(args.collect());
     }
 
+    // Then the target.*.rustflags value
+    if let Some(args) =
+        try!(config.get_list(&format!("target.{}.rustflags", target.unwrap_or(host)))) {
+        let args = args.val.into_iter().map(|a| a.0);
+        return Ok(args.collect());
+    }
+
     // Then the build.rustflags value
     if let Some(args) = try!(config.get_list("build.rustflags")) {
         let args = args.val.into_iter().map(|a| a.0);

Diff for: src/sysroot.rs

@@ -8,8 +8,8 @@ use cargo::util::{self, CargoResult, ChainError, Config, FileLock, Filesystem};
 use chrono::NaiveDate;
 use curl::http;
 use flate2::read::GzDecoder;
-use rustc_version::{self, Channel};
 use tar::Archive;
+use rustc_version::VersionMeta;
 use tempdir::TempDir;
 use term::color::GREEN;
 use toml::Value;
@@ -65,14 +65,9 @@ pub fn create(config: &Config,
               root: &Filesystem,
               verbose: bool,
               rustflags: &[String],
-              profiles: &Option<Value>)
+              profiles: &Option<Value>,
+              meta: VersionMeta)
               -> CargoResult<()> {
-    let meta = rustc_version::version_meta_for(&config.rustc_info().verbose_version);
-
-    if meta.channel != Channel::Nightly {
-        return Err(util::human("Only the nightly channel is currently supported"));
-    }
-
     let commit_date = try!(meta.commit_date
         .as_ref()
         .and_then(|s| NaiveDate::parse_from_str(s, "%Y-%m-%d").ok())
@@ -127,7 +122,7 @@ fn update_source(config: &Config,
             .timeout(0)
             .connect_timeout(30 * MS)
             .low_speed_limit(10 * B_PER_S)
-            .low_speed_timeout(30 * S);;
+            .low_speed_timeout(30 * S);
 
         let url = format!("https://static.rust-lang.org/dist/{}/{}",
                           date.format("%Y-%m-%d"),