Speed up integration tests (move building expectations)

Speed up running 'cargo test':
-Before: 2'17s
-After: 30s

Update to use new path:
Makefile, .travis.yml, CONTRIBUTING.md, tests/tests.rs

Delete unused expectation that fail to compile:
tests/expectations/moar_bitfields.rs
tests/expectations/variadic_template_args.rs

For every 'cargo test' run, the bindgen output where built.
We already test that the bindgen output match expectations/*.rs,
so there is no need to check it build unless the expectation is updated.

Move tests/expectations/*.rs to tests/expectations/tests/*.rs and make
tests/expectations a new dev-dependency package. This allow running:
 - cargo test -p tests_expectations

In addition to the speed up, we also get a clean output for the build
and test run. In particular, a number of warnings are generated that should
probably be silenced, and eventually enforced modifying travis to build:
 - RUSTFLAGS='-D warnings' cargo test -p tests_expectations

The benefit of having it as a new package is that it avoid polluting
the 'cargo test' output that should focus on bindgen.

Author: jeanphilippeD

.travis.yml

@@ -33,6 +33,7 @@ script:
   - git add -A
   - git diff @
   - git diff-index --quiet HEAD
+  - cargo test -p tests_expectations
   - cargo build --features "$BINDGEN_FEATURES _docs"
 
 notifications:

CONTRIBUTING.md

@@ -54,5 +54,8 @@ _docs = []
 name = "bindgen"
 path = "src/lib.rs"
 
+[dev-dependencies.tests_expectations]
+path = "tests/expectations"
+
 [[test]]
 name = "tests"

Cargo.toml

@@ -3,7 +3,7 @@ TEST_HEADERS := $(wildcard tests/headers/*.h) $(wildcard tests/headers/*.hpp)
 
 TEST_TARGETS := $(TEST_HEADERS:.h=.rs)
 TEST_TARGETS := $(TEST_TARGETS:.hpp=.rs)
-TEST_TARGETS := $(patsubst tests/headers/%, tests/expectations/%, $(TEST_TARGETS))
+TEST_TARGETS := $(patsubst tests/headers/%, tests/expectations/tests/%, $(TEST_TARGETS))
 
 BINDGEN := ./target/debug/bindgen
 
@@ -25,10 +25,10 @@ clean-tests:
 	$(RM) $(TEST_TARGETS)
 
 # TODO: Add options to add flags and whatnot
-tests/expectations/%.rs: tests/headers/%.h
+tests/expectations/tests/%.rs: tests/headers/%.h
 	@mkdir -p $(dir $@)
 	./tests/tools/run-bindgen.py $(BINDGEN) $< $@
 
-tests/expectations/%.rs: tests/headers/%.hpp
+tests/expectations/tests/%.rs: tests/headers/%.hpp
 	@mkdir -p $(dir $@)
 	./tests/tools/run-bindgen.py $(BINDGEN) $< $@

Makefile

@@ -0,0 +1,11 @@
+[package]
+name = "tests_expectations"
+description = "bindgen results when ran on ../headers/*"
+version = "0.1.0"
+authors = [
+  "Jyun-Yan You <[email protected]>",
+  "Emilio Cobos Álvarez <[email protected]>",
+  "The Servo project developers",
+]
+
+[dependencies]

tests/expectations/Cargo.toml

@@ -24,9 +24,9 @@ fn spawn_run_bindgen<P, Q, R>(run_bindgen: P,
     let bindgen = bindgen.as_ref();
     let header = header.as_ref();
 
-    // Convert from "tests/headers/foo.hpp" to "tests/expectations/foo.rs" by
+    // Convert from "tests/headers/foo.hpp" to "tests/expectations/tests/foo.rs" by
     // saving the filename, popping off "headers/foo.hpp", pushing
-    // "expectations", pushing the saved filename, and finally modifying the
+    // "expectations/tests", pushing the saved filename, and finally modifying the
     // extension.
 
     let mut expected = PathBuf::from(header);
@@ -36,6 +36,7 @@ fn spawn_run_bindgen<P, Q, R>(run_bindgen: P,
     expected.pop();
     expected.pop();
     expected.push("expectations");
+    expected.push("tests");
     expected.push(file_name);
     expected.set_extension("rs");
 

tests/expectations/moar_bitfields.rs

@@ -130,16 +130,6 @@ def generate_bindings(bindgen, dummy_uses, flags, header, output):
     command.append(header)
     run_cmd(command, cwd=os.getcwd(), env=make_bindgen_env())
 
-def test_generated_bindings(bindings):
-    """Run the generated bindings's #[test]s."""
-    name = None
-    # Do not delete the temp file, because we need to end the with block before
-    # we can run the tests.
-    with tempfile.NamedTemporaryFile(delete=False) as tests:
-        name = tests.name
-        run_cmd(["rustc", "--test", bindings, "-o", name])
-    run_cmd([name])
-
 def check_actual_vs_expected(expected_bindings, rust_bindings_path):
     """
     Check the actual generated rust bindings versus our expected generated rust
@@ -177,7 +167,6 @@ def main():
                       test_flags,
                       args.header,
                       args.rust_bindings)
-    test_generated_bindings(args.rust_bindings)
     check_actual_vs_expected(expected_bindings, args.rust_bindings)
     sys.exit(0)