Auto merge of #50276 - Zoxc:build-cleanup, r=alexcrichton

Misc tweaks

This:
- ~~Add explicit dependencies on `getops`~~
- Fixes the libtest-json test when `RUST_BACKTRACE=1` is set
- ~~Sets `opt-level` to `3`~~
- Removes the use of `staged_api` from `rustc_plugin`
- ~~Enables the Windows Error Reporting dialog when running rustc during bootstrapping~~
- Disables Windows Error Reporting dialog when running compiletest tests
- Enables backtraces when running rustc during bootstrapping
- ~~Removes the `librustc` dependency on `libtest`~~
- Triggers JIT debugging on Windows if rustc panics during bootstrapping

r? @alexcrichton

14 files changed, 73 insertions, 12 deletions

diff --git a/config.toml.example b/config.toml.example
index effe0084381..34fcc755b3a 100644
--- a/config.toml.example
+++ b/config.toml.example
@@ -346,6 +346,9 @@
 # Whether to deny warnings in crates
 #deny-warnings = true
 
+# Print backtrace on internal compiler errors during bootstrap
+#backtrace-on-ice = false
+
 # =============================================================================
 # Options for specific targets
 #
diff --git a/src/Cargo.lock b/src/Cargo.lock
index 0f08eaf596a..a2767bd290d 100644
--- a/src/Cargo.lock
+++ b/src/Cargo.lock
@@ -390,6 +390,7 @@ dependencies = [
  "env_logger 0.5.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "filetime 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
  "getopts 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.40 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "miow 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
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 _);
diff --git a/src/librustc/util/common.rs b/src/librustc/util/common.rs
index c74e42263ef..85533caffce 100644
--- a/src/librustc/util/common.rs
+++ b/src/librustc/util/common.rs
@@ -58,6 +58,17 @@ fn panic_hook(info: &panic::PanicInfo) {
         if backtrace {
             TyCtxt::try_print_query_stack();
         }
+
+        #[cfg(windows)]
+        unsafe {
+            if env::var("RUSTC_BREAK_ON_ICE").is_ok() {
+                extern "system" {
+                    fn DebugBreak();
+                }
+                // Trigger a debugger if we crashed during bootstrap
+                DebugBreak();
+            }
+        }
     }
 }
 
diff --git a/src/librustc_plugin/lib.rs b/src/librustc_plugin/lib.rs
index 622d8e51a6c..348aa6a7cef 100644
--- a/src/librustc_plugin/lib.rs
+++ b/src/librustc_plugin/lib.rs
@@ -65,7 +65,6 @@
        html_root_url = "https://doc.rust-lang.org/nightly/")]
 
 #![feature(rustc_diagnostic_macros)]
-#![feature(staged_api)]
 
 #[macro_use] extern crate syntax;
 
diff --git a/src/librustc_plugin/registry.rs b/src/librustc_plugin/registry.rs
index ebfd8785a0a..7e3c411c1d2 100644
--- a/src/librustc_plugin/registry.rs
+++ b/src/librustc_plugin/registry.rs
@@ -128,8 +128,6 @@ impl<'a> Registry<'a> {
     /// This can be used in place of `register_syntax_extension` to register legacy custom derives
     /// (i.e. attribute syntax extensions whose name begins with `derive_`). Legacy custom
     /// derives defined by this function do not trigger deprecation warnings when used.
-    #[unstable(feature = "rustc_private", issue = "27812")]
-    #[rustc_deprecated(since = "1.15.0", reason = "replaced by macros 1.1 (RFC 1861)")]
     pub fn register_custom_derive(&mut self, name: ast::Name, extension: SyntaxExtension) {
         assert!(name.as_str().starts_with("derive_"));
         self.whitelisted_custom_derives.push(name);
diff --git a/src/test/run-make-fulldeps/libtest-json/Makefile b/src/test/run-make-fulldeps/libtest-json/Makefile
index ec91ddfb9f9..a0bc8cf6688 100644
--- a/src/test/run-make-fulldeps/libtest-json/Makefile
+++ b/src/test/run-make-fulldeps/libtest-json/Makefile
@@ -6,7 +6,7 @@ OUTPUT_FILE := $(TMPDIR)/libtest-json-output.json
 
 all:
 	$(RUSTC) --test f.rs
-	$(call RUN,f) -Z unstable-options --test-threads=1 --format=json > $(OUTPUT_FILE) || true
+	RUST_BACKTRACE=0 $(call RUN,f) -Z unstable-options --test-threads=1 --format=json > $(OUTPUT_FILE) || true
 
 	cat $(OUTPUT_FILE) | "$(PYTHON)" validate_json.py
 
diff --git a/src/tools/compiletest/Cargo.toml b/src/tools/compiletest/Cargo.toml
index 77554f244c8..45cb147fbbc 100644
--- a/src/tools/compiletest/Cargo.toml
+++ b/src/tools/compiletest/Cargo.toml
@@ -19,5 +19,6 @@ rustfix = "0.2"
 libc = "0.2"
 
 [target.'cfg(windows)'.dependencies]
+lazy_static = "1.0"
 miow = "0.3"
 winapi = { version = "0.3", features = ["winerror"] }
diff --git a/src/tools/compiletest/src/main.rs b/src/tools/compiletest/src/main.rs
index a7849d53c3d..e2b446c99dc 100644
--- a/src/tools/compiletest/src/main.rs
+++ b/src/tools/compiletest/src/main.rs
@@ -23,6 +23,9 @@ extern crate libc;
 extern crate log;
 extern crate regex;
 #[macro_use]
+#[cfg(windows)]
+extern crate lazy_static;
+#[macro_use]
 extern crate serde_derive;
 extern crate serde_json;
 extern crate test;
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index fae75c352da..1bac9ef66bb 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -38,6 +38,39 @@ use std::str;
 
 use extract_gdb_version;
 
+#[cfg(windows)]
+fn disable_error_reporting<F: FnOnce() -> R, R>(f: F) -> R {
+    use std::sync::Mutex;
+    const SEM_NOGPFAULTERRORBOX: u32 = 0x0002;
+    extern "system" {
+        fn SetErrorMode(mode: u32) -> u32;
+    }
+
+    lazy_static! {
+        static ref LOCK: Mutex<()> = {
+            Mutex::new(())
+        };
+    }
+    // Error mode is a global variable, so lock it so only one thread will change it
+    let _lock = LOCK.lock().unwrap();
+
+    // Tell Windows to not show any UI on errors (such as 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.
+    unsafe {
+        let old_mode = SetErrorMode(SEM_NOGPFAULTERRORBOX); // read inherited flags
+        SetErrorMode(old_mode | SEM_NOGPFAULTERRORBOX);
+        let r = f();
+        SetErrorMode(old_mode);
+        r
+    }
+}
+
+#[cfg(not(windows))]
+fn disable_error_reporting<F: FnOnce() -> R, R>(f: F) -> R {
+    f()
+}
+
 /// The name of the environment variable that holds dynamic library locations.
 pub fn dylib_env_var() -> &'static str {
     if cfg!(windows) {
@@ -1578,8 +1611,7 @@ impl<'test> TestCx<'test> {
         let newpath = env::join_paths(&path).unwrap();
         command.env(dylib_env_var(), newpath);
 
-        let mut child = command
-            .spawn()
+        let mut child = disable_error_reporting(|| command.spawn())
             .expect(&format!("failed to exec `{:?}`", &command));
         if let Some(input) = input {
             child
diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index 8caf39fc27b..9a87fcb00d5 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -73,6 +73,7 @@ static WHITELIST: &'static [Crate] = &[
     Crate("flate2"),
     Crate("fuchsia-zircon"),
     Crate("fuchsia-zircon-sys"),
+    Crate("getopts"),
     Crate("humantime"),
     Crate("jobserver"),
     Crate("kernel32-sys"),