1 files changed, 130 insertions, 0 deletions
diff --git a/tests/ui/backtrace.rs b/tests/ui/backtrace.rs
new file mode 100644
index 00000000000..dd73dd9886a
--- /dev/null
+++ b/tests/ui/backtrace.rs
@@ -0,0 +1,130 @@
+// run-pass
+// ignore-android FIXME #17520
+// ignore-emscripten spawning processes is not supported
+// ignore-openbsd no support for libbacktrace without filename
+// ignore-sgx no processes
+// ignore-msvc see #62897 and `backtrace-debuginfo.rs` test
+// ignore-fuchsia Backtraces not symbolized
+// compile-flags:-g
+// compile-flags:-Cstrip=none
+
+use std::env;
+use std::process::{Command, Stdio};
+use std::str;
+
+#[inline(never)]
+fn foo() {
+    let _v = vec![1, 2, 3];
+    if env::var_os("IS_TEST").is_some() {
+        panic!()
+    }
+}
+
+#[inline(never)]
+fn double() {
+    struct Double;
+
+    impl Drop for Double {
+        fn drop(&mut self) { panic!("twice") }
+    }
+
+    let _d = Double;
+
+    panic!("once");
+}
+
+fn template(me: &str) -> Command {
+    let mut m = Command::new(me);
+    m.env("IS_TEST", "1")
+     .stdout(Stdio::piped())
+     .stderr(Stdio::piped());
+    return m;
+}
+
+fn expected(fn_name: &str) -> String {
+    format!(" backtrace::{}", fn_name)
+}
+
+#[cfg(not(panic = "abort"))]
+fn contains_verbose_expected(s: &str, fn_name: &str) -> bool {
+    // HACK(eddyb) work around the fact that verbosely demangled stack traces
+    // (from `RUST_BACKTRACE=full`, or, as is the case here, panic-in-panic)
+    // may contain symbols with hashes in them, i.e. `backtrace[...]::`.
+    let prefix = " backtrace";
+    let suffix = &format!("::{}", fn_name);
+    s.match_indices(prefix).any(|(i, _)| {
+        s[i + prefix.len()..]
+            .trim_start_matches('[')
+            .trim_start_matches(char::is_alphanumeric)
+            .trim_start_matches(']')
+            .starts_with(suffix)
+    })
+}
+
+fn runtest(me: &str) {
+    // Make sure that the stack trace is printed
+    let p = template(me).arg("fail").env("RUST_BACKTRACE", "1").spawn().unwrap();
+    let out = p.wait_with_output().unwrap();
+    assert!(!out.status.success());
+    let s = str::from_utf8(&out.stderr).unwrap();
+    assert!(s.contains("stack backtrace") && s.contains(&expected("foo")),
+            "bad output: {}", s);
+    assert!(s.contains(" 0:"), "the frame number should start at 0");
+
+    // Make sure the stack trace is *not* printed
+    // (Remove RUST_BACKTRACE from our own environment, in case developer
+    // is running `make check` with it on.)
+    let p = template(me).arg("fail").env_remove("RUST_BACKTRACE").spawn().unwrap();
+    let out = p.wait_with_output().unwrap();
+    assert!(!out.status.success());
+    let s = str::from_utf8(&out.stderr).unwrap();
+    assert!(!s.contains("stack backtrace") && !s.contains(&expected("foo")),
+            "bad output2: {}", s);
+
+    // Make sure the stack trace is *not* printed
+    // (RUST_BACKTRACE=0 acts as if it were unset from our own environment,
+    // in case developer is running `make check` with it set.)
+    let p = template(me).arg("fail").env("RUST_BACKTRACE","0").spawn().unwrap();
+    let out = p.wait_with_output().unwrap();
+    assert!(!out.status.success());
+    let s = str::from_utf8(&out.stderr).unwrap();
+    assert!(!s.contains("stack backtrace") && !s.contains(" - foo"),
+            "bad output3: {}", s);
+
+    #[cfg(not(panic = "abort"))]
+    {
+        // Make sure a stack trace is printed
+        let p = template(me).arg("double-fail").spawn().unwrap();
+        let out = p.wait_with_output().unwrap();
+        assert!(!out.status.success());
+        let s = str::from_utf8(&out.stderr).unwrap();
+        // loosened the following from double::h to double:: due to
+        // spurious failures on mac, 32bit, optimized
+        assert!(s.contains("stack backtrace") && contains_verbose_expected(s, "double"),
+                "bad output3: {}", s);
+
+        // Make sure a stack trace isn't printed too many times
+        let p = template(me).arg("double-fail")
+                                    .env("RUST_BACKTRACE", "1").spawn().unwrap();
+        let out = p.wait_with_output().unwrap();
+        assert!(!out.status.success());
+        let s = str::from_utf8(&out.stderr).unwrap();
+        let mut i = 0;
+        for _ in 0..2 {
+            i += s[i + 10..].find("stack backtrace").unwrap() + 10;
+        }
+        assert!(s[i + 10..].find("stack backtrace").is_none(),
+                "bad output4: {}", s);
+    }
+}
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    if args.len() >= 2 && args[1] == "fail" {
+        foo();
+    } else if args.len() >= 2 && args[1] == "double-fail" {
+        double();
+    } else {
+        runtest(&args[0]);
+    }
+}