Rollup merge of rust-lang#126036 - Oneirical:the-intelligent-intestor, r=jieyouxu

Migrate `run-make/short-ice` to `rmake`

Part of rust-lang#121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).

try-job: x86_64-msvc

Author: compiler-errors

src/tools/run-make-support/src/rustc.rs

@@ -105,6 +105,12 @@ impl Rustc {
         self
     }
 
+    //Adjust the backtrace level, displaying more detailed information at higher levels.
+    pub fn set_backtrace_level<R: AsRef<OsStr>>(&mut self, level: R) -> &mut Self {
+        self.cmd.env("RUST_BACKTRACE", level);
+        self
+    }
+
     /// Specify path to the output file. Equivalent to `-o`` in rustc.
     pub fn output<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
         self.cmd.arg("-o");

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -214,7 +214,6 @@ run-make/sepcomp-cci-copies/Makefile
 run-make/sepcomp-inlining/Makefile
 run-make/sepcomp-separate/Makefile
 run-make/share-generics-dylib/Makefile
-run-make/short-ice/Makefile
 run-make/silly-file-names/Makefile
 run-make/simd-ffi/Makefile
 run-make/split-debuginfo/Makefile

tests/run-make/short-ice/Makefile

@@ -0,0 +1,42 @@
+// Backtraces in internal compiler errors used to be unbearably long, spanning
+// multiple hundreds of lines. A fix was pushed in #108938, and this test gathers
+// varied metrics on level 1 and full-level backtraces to check that the output
+// was shortened down to an appropriate length.
+// See https://github.com/rust-lang/rust/issues/107910
+
+//@ ignore-windows
+// Reason: the assert_eq! on line 32 fails, as error output on Windows is different.
+
+use run_make_support::rustc;
+
+fn main() {
+    let rust_test_1 =
+        rustc().set_backtrace_level("1").input("src/lib.rs").arg("-Ztreat-err-as-bug=1").run_fail();
+    let rust_test_2 = rustc()
+        .set_backtrace_level("full")
+        .input("src/lib.rs")
+        .arg("-Ztreat-err-as-bug=1")
+        .run_fail();
+
+    let mut rust_test_log_1 = rust_test_1.stderr_utf8();
+    rust_test_log_1.push_str(&rust_test_1.stdout_utf8());
+    let rust_test_log_1 = rust_test_log_1.as_str();
+
+    let mut rust_test_log_2 = rust_test_2.stderr_utf8();
+    rust_test_log_2.push_str(&rust_test_2.stdout_utf8());
+    let rust_test_log_2 = rust_test_log_2.as_str();
+
+    let rustc_query_count_full = count_lines_with(rust_test_log_2, "rustc_query_");
+
+    assert!(rust_test_log_1.lines().count() < rust_test_log_2.lines().count());
+    assert_eq!(
+        count_lines_with(rust_test_log_2, "__rust_begin_short_backtrace"),
+        count_lines_with(rust_test_log_2, "__rust_end_short_backtrace")
+    );
+    assert!(count_lines_with(rust_test_log_1, "rustc_query_") + 5 < rustc_query_count_full);
+    assert!(rustc_query_count_full > 5);
+}
+
+fn count_lines_with(s: &str, search: &str) -> usize {
+    s.lines().filter(|l| l.contains(search)).count()
+}