Don't put hashes in libraries of the root crate

The root crate often has artifacts which are later intended for distribution of
some form, so adding a hash will just make predicting the file name difficult.
The hash also isn't necessary as it's guaranteed to not conflict with other
files (no other dependencies are in the same directory) and all other libraries
have metadata so symbols will not conflict.

Closes #1484

src/cargo/ops/cargo_clean.rs

@@ -63,7 +63,7 @@ pub fn clean(manifest_path: &Path, opts: &CleanOptions) -> CargoResult<()> {
         try!(rm_rf(&layout.fingerprint(&pkg)));
         let profiles = [Profile::default_dev(), Profile::default_test()];
         for profile in profiles.iter() {
-            for filename in try!(cx.target_filenames(target, profile)).iter() {
+            for filename in try!(cx.target_filenames(&pkg, target, profile)).iter() {
                 try!(rm_rf(&layout.dest().join(&filename)));
                 try!(rm_rf(&layout.deps().join(&filename)));
             }

src/cargo/ops/cargo_rustc/context.rs

@@ -257,8 +257,8 @@ impl<'a, 'b: 'a> Context<'a, 'b> {
     }
 
     /// Get the metadata for a target in a specific profile
-    pub fn target_metadata(&self, target: &Target, profile: &Profile)
-                           -> Option<Metadata> {
+    pub fn target_metadata(&self, pkg: &Package, target: &Target,
+                           profile: &Profile) -> Option<Metadata> {
         let metadata = target.metadata();
         if target.is_lib() && profile.test {
             // Libs and their tests are built in parallel, so we need to make
@@ -269,19 +269,26 @@ impl<'a, 'b: 'a> Context<'a, 'b> {
             })
         } else if target.is_bin() && profile.test {
             // Make sure that the name of this test executable doesn't
-            // conflicts with a library that has the same name and is
+            // conflict with a library that has the same name and is
             // being tested
-            let mut metadata = self.resolve.root().generate_metadata();
+            let mut metadata = pkg.package_id().generate_metadata();
             metadata.mix(&format!("bin-{}", target.name()));
             Some(metadata)
+        } else if pkg.package_id() == self.resolve.root() && !profile.test {
+            // If we're not building a unit test then the root package never
+            // needs any metadata as it's guaranteed to not conflict with any
+            // other output filenames. This means that we'll have predictable
+            // file names like `target/debug/libfoo.{a,so,rlib}` and such.
+            None
         } else {
             metadata.map(|m| m.clone())
         }
     }
 
     /// Returns the file stem for a given target/profile combo
-    pub fn file_stem(&self, target: &Target, profile: &Profile) -> String {
-        match self.target_metadata(target, profile) {
+    pub fn file_stem(&self, pkg: &Package, target: &Target,
+                     profile: &Profile) -> String {
+        match self.target_metadata(pkg, target, profile) {
             Some(ref metadata) => format!("{}{}", target.crate_name(),
                                           metadata.extra_filename),
             None if target.allows_underscores() => target.name().to_string(),
@@ -291,9 +298,9 @@ impl<'a, 'b: 'a> Context<'a, 'b> {
 
     /// Return the filenames that the given target for the given profile will
     /// generate.
-    pub fn target_filenames(&self, target: &Target, profile: &Profile)
-                            -> CargoResult<Vec<String>> {
-        let stem = self.file_stem(target, profile);
+    pub fn target_filenames(&self, pkg: &Package, target: &Target,
+                            profile: &Profile) -> CargoResult<Vec<String>> {
+        let stem = self.file_stem(pkg, target, profile);
         let suffix = if target.for_host() {&self.host_exe} else {&self.target_exe};
 
         let mut ret = Vec::new();

src/cargo/ops/cargo_rustc/fingerprint.rs

@@ -57,7 +57,7 @@ pub fn prepare_target<'a, 'b>(cx: &mut Context<'a, 'b>,
     let root = cx.out_dir(pkg, kind, target);
     let mut missing_outputs = false;
     if !profile.doc {
-        for filename in try!(cx.target_filenames(target, profile)).iter() {
+        for filename in try!(cx.target_filenames(pkg, target, profile)).iter() {
             missing_outputs |= fs::metadata(root.join(filename)).is_err();
         }
     }

src/cargo/ops/cargo_rustc/mod.rs

@@ -133,7 +133,7 @@ pub fn compile_targets<'a, 'b>(targets: &[(&'a Target, &'a Profile)],
     cx.compilation.extra_env.insert("OUT_DIR".to_string(), out_dir);
 
     for &(target, profile) in targets {
-        for filename in try!(cx.target_filenames(target, profile)).iter() {
+        for filename in try!(cx.target_filenames(pkg, target, profile)).iter() {
             let dst = cx.out_dir(pkg, Kind::Target, target).join(filename);
             if profile.test {
                 cx.compilation.tests.push((target.name().to_string(), dst));
@@ -154,7 +154,7 @@ pub fn compile_targets<'a, 'b>(targets: &[(&'a Target, &'a Profile)],
                 if profile.doc { continue }
                 if cx.compilation.libraries.contains_key(&pkgid) { continue }
 
-                let v = try!(cx.target_filenames(target, profile));
+                let v = try!(cx.target_filenames(pkg, target, profile));
                 let v = v.into_iter().map(|f| {
                     (target.clone(),
                      cx.out_dir(pkg, Kind::Target, target).join(f))
@@ -342,7 +342,7 @@ fn rustc(package: &Package, target: &Target, profile: &Profile,
         }
         let exec_engine = cx.exec_engine.clone();
 
-        let filenames = try!(cx.target_filenames(target, profile));
+        let filenames = try!(cx.target_filenames(package, target, profile));
         let root = cx.out_dir(package, kind, target);
 
         // Prepare the native lib state (extra -L and -l flags)
@@ -367,7 +367,7 @@ fn rustc(package: &Package, target: &Target, profile: &Profile,
         let rustc_dep_info_loc = if do_rename {
             root.join(&crate_name)
         } else {
-            root.join(&cx.file_stem(target, profile))
+            root.join(&cx.file_stem(package, target, profile))
         }.with_extension("d");
         let dep_info_loc = fingerprint::dep_info_loc(cx, package, target,
                                                      profile, kind);
@@ -678,7 +678,7 @@ fn build_base_args(cx: &Context,
         None => {}
     }
 
-    match cx.target_metadata(target, profile) {
+    match cx.target_metadata(pkg, target, profile) {
         Some(m) => {
             cmd.arg("-C").arg(&format!("metadata={}", m.metadata));
             cmd.arg("-C").arg(&format!("extra-filename={}", m.extra_filename));
@@ -753,7 +753,7 @@ fn build_deps_args(cmd: &mut CommandPrototype,
             Kind::Target => Kind::Target,
         });
 
-        for filename in try!(cx.target_filenames(target, profile)).iter() {
+        for filename in try!(cx.target_filenames(pkg, target, profile)).iter() {
             if filename.ends_with(".a") { continue }
             let mut v = OsString::new();
             v.push(&target.crate_name());

tests/test_cargo_build_lib.rs

@@ -10,8 +10,6 @@ fn verbose_output_for_lib(p: &ProjectBuilder) -> String {
     format!("\
 {compiling} {name} v{version} ({url})
 {running} `rustc src{sep}lib.rs --crate-name {name} --crate-type lib -g \
-        -C metadata=[..] \
-        -C extra-filename=-[..] \
         --out-dir {dir}{sep}target{sep}debug \
         --emit=dep-info,link \
         -L dependency={dir}{sep}target{sep}debug \

tests/test_cargo_compile.rs

@@ -842,8 +842,6 @@ test!(verbose_build {
                 execs().with_status(0).with_stdout(&format!("\
 {compiling} test v0.0.0 ({url})
 {running} `rustc src[..]lib.rs --crate-name test --crate-type lib -g \
-        -C metadata=[..] \
-        -C extra-filename=-[..] \
         --out-dir {dir}[..]target[..]debug \
         --emit=dep-info,link \
         -L dependency={dir}[..]target[..]debug \
@@ -871,8 +869,6 @@ test!(verbose_release_build {
 {compiling} test v0.0.0 ({url})
 {running} `rustc src[..]lib.rs --crate-name test --crate-type lib \
         -C opt-level=3 \
-        -C metadata=[..] \
-        -C extra-filename=-[..] \
         --out-dir {dir}[..]target[..]release \
         --emit=dep-info,link \
         -L dependency={dir}[..]target[..]release \
@@ -925,8 +921,6 @@ test!(verbose_release_build_deps {
 {compiling} test v0.0.0 ({url})
 {running} `rustc src[..]lib.rs --crate-name test --crate-type lib \
         -C opt-level=3 \
-        -C metadata=[..] \
-        -C extra-filename=-[..] \
         --out-dir {dir}[..]target[..]release \
         --emit=dep-info,link \
         -L dependency={dir}[..]target[..]release \
@@ -1621,6 +1615,30 @@ cyclic package dependency: package `foo v0.0.1 ([..])` depends on itself
 "));
 });
 
+test!(predictable_filenames {
+    let p = project("foo")
+        .file("Cargo.toml", r#"
+            [package]
+            name = "foo"
+            version = "0.0.1"
+            authors = []
+
+            [lib]
+            name = "foo"
+            crate-type = ["staticlib", "dylib", "rlib"]
+        "#)
+        .file("src/lib.rs", "");
+
+    assert_that(p.cargo_process("build").arg("-v"),
+                execs().with_status(0));
+    assert_that(&p.root().join("target/debug/libfoo.a"), existing_file());
+    assert_that(&p.root().join("target/debug/libfoo.rlib"), existing_file());
+    let dylib_name = format!("{}foo{}", env::consts::DLL_PREFIX,
+                             env::consts::DLL_SUFFIX);
+    assert_that(&p.root().join("target/debug").join(dylib_name),
+                existing_file());
+});
+
 test!(dashes_to_underscores {
     let p = project("foo")
         .file("Cargo.toml", r#"

tests/test_cargo_compile_custom_build.rs

@@ -768,7 +768,6 @@ test!(build_cmd_with_a_build_cmd {
     --extern a=[..]liba-[..].rlib`
 {running} `[..]foo-[..]build-script-build[..]`
 {running} `rustc [..]lib.rs --crate-name foo --crate-type lib -g \
-    -C metadata=[..] -C extra-filename=-[..] \
     --out-dir [..]target[..]debug --emit=dep-info,link \
     -L [..]target[..]debug -L [..]target[..]deps`
 ", compiling = COMPILING, running = RUNNING)));

tests/test_cargo_profiles.rs

@@ -30,8 +30,6 @@ test!(profile_overrides {
 {running} `rustc src{sep}lib.rs --crate-name test --crate-type lib \
         -C opt-level=1 \
         -C debug-assertions=on \
-        -C metadata=[..] \
-        -C extra-filename=-[..] \
         -C rpath \
         --out-dir {dir}{sep}target{sep}debug \
         --emit=dep-info,link \
@@ -95,8 +93,6 @@ test!(top_level_overrides_deps {
 {running} `rustc src{sep}lib.rs --crate-name test --crate-type lib \
         -C opt-level=1 \
         -g \
-        -C metadata=[..] \
-        -C extra-filename=-[..] \
         --out-dir {dir}{sep}target{sep}release \
         --emit=dep-info,link \
         -L dependency={dir}{sep}target{sep}release \