Misc tweaks

4 files changed, 18 insertions, 6 deletions

diff --git a/src/bootstrap/bin/rustc.rs b/src/bootstrap/bin/rustc.rs
index b6ae824c376..3f97accaa4d 100644
--- a/src/bootstrap/bin/rustc.rs
+++ b/src/bootstrap/bin/rustc.rs
@@ -107,6 +107,13 @@ fn main() {
              env::join_paths(&dylib_path).unwrap());
     let mut maybe_crate = None;
 
+    // Print backtrace in case of ICE
+    if env::var("RUSTC_BACKTRACE_ON_ICE").is_ok() && env::var("RUST_BACKTRACE").is_err() {
+        cmd.env("RUST_BACKTRACE", "1");
+    }
+
+    cmd.env("RUSTC_BREAK_ON_ICE", "1");
+
     if let Some(target) = target {
         // The stage0 compiler has a special sysroot distinct from what we
         // actually downloaded, so we just always pass the `--sysroot` option.
diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index 08bb8ab4815..43387e28565 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -706,6 +706,10 @@ impl<'a> Builder<'a> {
             cargo.env("RUSTC_PRINT_STEP_TIMINGS", "1");
         }
 
+        if self.config.backtrace_on_ice {
+            cargo.env("RUSTC_BACKTRACE_ON_ICE", "1");
+        }
+
         cargo.env("RUSTC_VERBOSE", format!("{}", self.verbosity));
 
         // in std, we want to avoid denying warnings for stage 0 as that makes cfg's painful.
diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index 7175f6a6764..6dd6291be23 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -72,6 +72,7 @@ pub struct Config {
     pub dry_run: bool,
 
     pub deny_warnings: bool,
+    pub backtrace_on_ice: bool,
 
     // llvm codegen options
     pub llvm_enabled: bool,
@@ -306,6 +307,7 @@ struct Rust {
     wasm_syscall: Option<bool>,
     lld: Option<bool>,
     deny_warnings: Option<bool>,
+    backtrace_on_ice: Option<bool>,
 }
 
 /// TOML representation of how each build target is configured.
@@ -531,6 +533,7 @@ impl Config {
             config.musl_root = rust.musl_root.clone().map(PathBuf::from);
             config.save_toolstates = rust.save_toolstates.clone().map(PathBuf::from);
             set(&mut config.deny_warnings, rust.deny_warnings.or(flags.warnings));
+            set(&mut config.backtrace_on_ice, rust.backtrace_on_ice);
 
             if let Some(ref backends) = rust.codegen_backends {
                 config.rust_codegen_backends = backends.iter()
diff --git a/src/bootstrap/job.rs b/src/bootstrap/job.rs
index fa3ba02482f..6445ce8da33 100644
--- a/src/bootstrap/job.rs
+++ b/src/bootstrap/job.rs
@@ -122,12 +122,10 @@ struct JOBOBJECT_BASIC_LIMIT_INFORMATION {
 }
 
 pub unsafe fn setup(build: &mut Build) {
-    // Tell Windows to not show any UI on errors (such as not finding a required dll
-    // during startup or terminating abnormally).  This is important for running tests,
-    // since some of them use abnormal termination by design.
-    // This mode is inherited by all child processes.
-    let mode = SetErrorMode(SEM_NOGPFAULTERRORBOX); // read inherited flags
-    SetErrorMode(mode | SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX);
+    // Enable the Windows Error Reporting dialog which msys disables,
+    // so we can JIT debug rustc
+    let mode = SetErrorMode(0);
+    SetErrorMode(mode & !SEM_NOGPFAULTERRORBOX);
 
     // Create a new job object for us to use
     let job = CreateJobObjectW(0 as *mut _, 0 as *const _);