add MIRIFLAGS env var to set Miri's flags; make cargo-miri test suite pass again

Author: RalfJung

cargo-miri/bin.rs

@@ -503,6 +503,7 @@ fn phase_cargo_rustc(args: env::ArgsOs) {
                 }
             }
             cmd.arg(format!("{}={}", emit_flag, val.join(",")));
+            // FIXME: due to this, the `.rlib` file does not get created and cargo re-triggers the build each time.
         } else {
             cmd.arg(arg);
         }
@@ -541,13 +542,13 @@ fn phase_cargo_runner(binary: &OsStr, binary_args: env::ArgsOs) {
         .unwrap_or_else(|_| show_error(format!("Unable to remove file {:?}", binary)));
 
     let mut cmd = miri();
-    // Forward rustc arguments, with our sysroot. We need to patch "--extern" filenames because
+    // Forward rustc arguments. We need to patch "--extern" filenames because
     // we forced a check-only build without cargo knowing about that: replace `.rlib` suffix by `.rmeta`.
     let mut args = info.args.into_iter();
     let extern_flag = "--extern";
     while let Some(arg) = args.next() {
         if arg.to_str() == Some(extern_flag) {
-            let next_arg = args.next().expect("`--extern` shoulw be followed by a filename");
+            let next_arg = args.next().expect("`--extern` should be followed by a filename");
             let next_arg = next_arg.to_str().expect("Cannot work with non-UTF-8 extern filenames");
             let next_arg = next_arg.strip_suffix(".rlib").expect("all extern filenames should end in `.rlib`");
             cmd.arg(extern_flag);
@@ -556,10 +557,21 @@ fn phase_cargo_runner(binary: &OsStr, binary_args: env::ArgsOs) {
             cmd.arg(arg);
         }
     }
+    // Set sysroot.
     let sysroot =
         env::var_os("MIRI_SYSROOT").expect("The wrapper should have set MIRI_SYSROOT");
     cmd.arg("--sysroot");
     cmd.arg(sysroot);
+    // Respect `MIRIFLAGS`.
+    if let Ok(a) = env::var("MIRIFLAGS") {
+        // This code is taken from `RUSTFLAGS` handling in cargo.
+        let args = a
+                .split(' ')
+                .map(str::trim)
+                .filter(|s| !s.is_empty())
+                .map(str::to_string);
+        cmd.args(args);
+    }
 
     // Then pass binary arguments.
     cmd.arg("--");

test-cargo-miri/run-test.py

@@ -21,13 +21,16 @@ def cargo_miri(cmd):
         args += ["--target", os.environ['MIRI_TEST_TARGET']]
     return args
 
-def test(name, cmd, stdout_ref, stderr_ref):
+def test(name, cmd, stdout_ref, stderr_ref, env={}):
     print("==> Testing `{}` <==".format(name))
     ## Call `cargo miri`, capture all output
+    p_env = os.environ.copy()
+    p_env.update(env)
     p = subprocess.Popen(
         cmd,
         stdout=subprocess.PIPE,
-        stderr=subprocess.PIPE
+        stderr=subprocess.PIPE,
+        env=p_env,
     )
     (stdout, stderr) = p.communicate()
     stdout = stdout.decode("UTF-8")
@@ -55,29 +58,31 @@ def test_cargo_miri_run():
         "stdout.ref", "stderr.ref"
     )
     test("cargo miri run (with arguments)",
-        cargo_miri("run") + ["--", "--", "hello world", '"hello world"'],
+        cargo_miri("run") + ["--", "hello world", '"hello world"'],
         "stdout.ref", "stderr.ref2"
     )
 
 def test_cargo_miri_test():
     test("cargo miri test",
-        cargo_miri("test") + ["--", "-Zmiri-seed=feed"],
-        "test.stdout.ref", "test.stderr.ref"
+        cargo_miri("test"),
+        "test.stdout.ref", "test.stderr.ref",
+        env={'MIRIFLAGS': "-Zmiri-seed=feed"},
     )
     test("cargo miri test (with filter)",
-        cargo_miri("test") + ["--", "--", "le1"],
+        cargo_miri("test") + ["--", "--format=pretty", "le1"],
         "test.stdout.ref2", "test.stderr.ref"
     )
     test("cargo miri test (without isolation)",
-        cargo_miri("test") + ["--", "-Zmiri-disable-isolation", "--", "num_cpus"],
-        "test.stdout.ref3", "test.stderr.ref"
+        cargo_miri("test") + ["--", "--format=pretty", "num_cpus"],
+        "test.stdout.ref3", "test.stderr.ref",
+        env={'MIRIFLAGS': "-Zmiri-disable-isolation"},
     )
     test("cargo miri test (test target)",
-        cargo_miri("test") + ["--test", "test"],
+        cargo_miri("test") + ["--test", "test", "--", "--format=pretty"],
         "test.stdout.ref4", "test.stderr.ref"
     )
     test("cargo miri test (bin target)",
-        cargo_miri("test") + ["--bin", "cargo-miri-test"],
+        cargo_miri("test") + ["--bin", "cargo-miri-test", "--", "--format=pretty"],
         "test.stdout.ref5", "test.stderr.ref"
     )
 

test-cargo-miri/test.stdout.ref

@@ -1,18 +1,10 @@
 
 running 1 test
-test test::rng ... ok
-
+.
 test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
 
 
 running 7 tests
-test do_panic ... ok
-test does_not_work_on_miri ... ignored
-test entropy_rng ... ok
-test fail_index_check ... ok
-test num_cpus ... ok
-test simple1 ... ok
-test simple2 ... ok
-
+.i.....
 test result: ok. 6 passed; 0 failed; 1 ignored; 0 measured; 0 filtered out