From e9d46f8cb10eec1f8ee19ed2aab385d17ec85757 Mon Sep 17 00:00:00 2001
From: Cody P Schafer <dev@codyps.com>
Date: Tue, 18 Nov 2014 01:40:21 -0500
Subject: [PATCH 02/10] Target: add default target.json path:
 $libdir/rust/targets

---
 src/librustc/session/config.rs  |  6 +++---
 src/librustc/session/mod.rs     |  8 ++++++--
 src/librustc_back/target/mod.rs | 14 +++++++++++---
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs
index c5db7cd..2b9069f 100644
--- a/src/librustc/session/config.rs
+++ b/src/librustc/session/config.rs
@@ -38,7 +38,7 @@ use getopts;
 use std::collections::HashMap;
 use std::env;
 use std::fmt;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use llvm;
 
@@ -655,8 +655,8 @@ pub fn build_configuration(sess: &Session) -> ast::CrateConfig {
     v
 }
 
-pub fn build_target_config(opts: &Options, sp: &SpanHandler) -> Config {
-    let target = match Target::search(&opts.target_triple) {
+pub fn build_target_config(sysroot: &Path, opts: &Options, sp: &SpanHandler) -> Config {
+    let target = match Target::search(sysroot, &opts.target_triple[..]) {
         Ok(t) => t,
         Err(e) => {
             sp.handler().fatal(&format!("Error loading target specification: {}", e));
diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index 99a58f0..d25e476 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -385,14 +385,18 @@ pub fn build_session_(sopts: config::Options,
                       local_crate_source_file: Option<PathBuf>,
                       span_diagnostic: diagnostic::SpanHandler)
                       -> Session {
-    let host = match Target::search(config::host_triple()) {
+    let sysroot = match sopts.maybe_sysroot {
+        Some(ref x) => PathBuf::from(x),
+        None => filesearch::get_or_default_sysroot()
+    };
+    let host = match Target::search(&sysroot, config::host_triple()) {
         Ok(t) => t,
         Err(e) => {
             span_diagnostic.handler()
                 .fatal(&format!("Error loading host specification: {}", e));
     }
     };
-    let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
+    let target_cfg = config::build_target_config(&sysroot, &sopts, &span_diagnostic);
     let p_s = parse::ParseSess::with_span_handler(span_diagnostic);
     let default_sysroot = match sopts.maybe_sysroot {
         Some(_) => None,
diff --git a/src/librustc_back/target/mod.rs b/src/librustc_back/target/mod.rs
index ce05a88..1d1ff70 100644
--- a/src/librustc_back/target/mod.rs
+++ b/src/librustc_back/target/mod.rs
@@ -49,6 +49,8 @@ use serialize::json::Json;
 use std::default::Default;
 use std::io::prelude::*;
 use syntax::{diagnostic, abi};
+use std::borrow::ToOwned;
+use std::path::Path;
 
 mod android_base;
 mod apple_base;
@@ -320,12 +322,13 @@ impl Target {
     ///
     /// The error string could come from any of the APIs called, including
     /// filesystem access and JSON decoding.
-    pub fn search(target: &str) -> Result<Target, String> {
+    pub fn search(sysroot: &Path, target: &str) -> Result<Target, String> {
         use std::env;
         use std::ffi::OsString;
         use std::fs::File;
         use std::path::{Path, PathBuf};
         use serialize::json;
+        use std::iter::IntoIterator;
 
         fn load_file(path: &Path) -> Result<Target, String> {
             let mut f = try!(File::open(path).map_err(|e| e.to_string()));
@@ -417,9 +420,14 @@ impl Target {
         let target_path = env::var_os("RUST_TARGET_PATH")
                               .unwrap_or(OsString::new());
 
-        // FIXME 16351: add a sane default search path?
+        let mut default_path = sysroot.to_owned();
+        default_path.push(env!("CFG_LIBDIR_RELATIVE"));
+        default_path.push("rustlib");
 
-        for dir in env::split_paths(&target_path) {
+        let paths = env::split_paths(&target_path)
+            .chain(Some(default_path).into_iter());
+
+        for dir in paths {
             let p =  dir.join(&path);
             if p.is_file() {
                 return load_file(&p);
-- 
2.5.1