Making ICEs and test them in incremental

src/librustc/query/mod.rs

@@ -29,6 +29,12 @@ use syntax_pos::symbol::InternedString;
 // Queries marked with `fatal_cycle` do not need the latter implementation,
 // as they will raise an fatal error on query cycles instead.
 rustc_queries! {
+    Other {
+        query trigger_delay_span_bug(key: DefId) -> () {
+            desc { "trigger a delay span bug" }
+        }
+    }
+
     Other {
         /// Records the type of every item.
         query type_of(key: DefId) -> Ty<'tcx> {

src/librustc_codegen_utils/lib.rs

@@ -19,26 +19,52 @@ extern crate rustc;
 
 use rustc::ty::TyCtxt;
 use rustc::ty::query::Providers;
-use rustc::hir::def_id::LOCAL_CRATE;
+use rustc::hir::def_id::{LOCAL_CRATE, DefId};
 use syntax::symbol::sym;
 
 pub mod link;
 pub mod codegen_backend;
 pub mod symbol_names;
 pub mod symbol_names_test;
 
+
+pub fn trigger_delay_span_bug(tcx: TyCtxt<'_>, key: DefId) {
+    tcx.sess.delay_span_bug(tcx.def_span(key), "compilation successful");
+}
+
 /// check for the #[rustc_error] annotation, which forces an
 /// error in codegen. This is used to write compile-fail tests
 /// that actually test that compilation succeeds without
 /// reporting an error.
 pub fn check_for_rustc_errors_attr(tcx: TyCtxt<'_>) {
     if let Some((def_id, _)) = tcx.entry_fn(LOCAL_CRATE) {
-        if tcx.has_attr(def_id, sym::rustc_error) {
-            tcx.sess.span_fatal(tcx.def_span(def_id), "compilation successful");
+        let attrs = &*tcx.get_attrs(def_id);
+        for attr in attrs {
+            if attr.check_name(sym::rustc_error) {
+                match attr.meta_item_list() {
+                    // check if there is a #[rustc_error(delayed)]
+                    Some(list) => {
+                        if list.iter().any(|list_item| {
+                            list_item.ident().map(|i| i.name) ==
+                                Some(sym::delay_span_bug_from_inside_query)
+                        }) {
+                            tcx.ensure().trigger_delay_span_bug(def_id);
+                        }
+                    }
+                    // bare #[rustc_error]
+                    None => {
+                        tcx.sess.span_fatal(tcx.def_span(def_id), "compilation successful");
+                    }
+                }
+            }
         }
     }
 }
 
 pub fn provide(providers: &mut Providers<'_>) {
     crate::symbol_names::provide(providers);
+    *providers = Providers {
+        trigger_delay_span_bug,
+        ..*providers
+    };
 }

src/libsyntax/feature_gate/builtin_attrs.rs

@@ -533,7 +533,10 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     rustc_attr!(TEST, rustc_variance, Normal, template!(Word)),
     rustc_attr!(TEST, rustc_layout, Normal, template!(List: "field1, field2, ...")),
     rustc_attr!(TEST, rustc_regions, Normal, template!(Word)),
-    rustc_attr!(TEST, rustc_error, Whitelisted, template!(Word)),
+    rustc_attr!(
+        TEST, rustc_error, Whitelisted,
+        template!(Word, List: "delay_span_bug_from_inside_query")
+    ),
     rustc_attr!(TEST, rustc_dump_user_substs, Whitelisted, template!(Word)),
     rustc_attr!(TEST, rustc_if_this_changed, Whitelisted, template!(Word, List: "DepNode")),
     rustc_attr!(TEST, rustc_then_this_would_need, Whitelisted, template!(List: "DepNode")),

src/libsyntax_pos/symbol.rs

@@ -234,6 +234,7 @@ symbols! {
         default_lib_allocator,
         default_type_parameter_fallback,
         default_type_params,
+        delay_span_bug_from_inside_query,
         deny,
         deprecated,
         deref,

src/test/incremental/delayed_span_bug.rs

@@ -0,0 +1,8 @@
+// revisions: cfail1 cfail2
+// should-ice
+// error-pattern: compilation successful
+
+#![feature(rustc_attrs)]
+
+#[rustc_error(delay_span_bug_from_inside_query)]
+fn main() {}

src/tools/compiletest/src/header.rs

@@ -376,6 +376,8 @@ pub struct TestProps {
     // If true, `rustfix` will only apply `MachineApplicable` suggestions.
     pub rustfix_only_machine_applicable: bool,
     pub assembly_output: Option<String>,
+    // If true, the test is expected to ICE
+    pub should_ice: bool,
 }
 
 impl TestProps {
@@ -414,6 +416,7 @@ impl TestProps {
             run_rustfix: false,
             rustfix_only_machine_applicable: false,
             assembly_output: None,
+            should_ice: false,
         }
     }
 
@@ -464,6 +467,10 @@ impl TestProps {
                 self.pp_exact = config.parse_pp_exact(ln, testfile);
             }
 
+            if !self.should_ice {
+                self.should_ice = config.parse_should_ice(ln);
+            }
+
             if !self.build_aux_docs {
                 self.build_aux_docs = config.parse_build_aux_docs(ln);
             }
@@ -688,6 +695,9 @@ fn iter_header(testfile: &Path, cfg: Option<&str>, it: &mut dyn FnMut(&str)) {
 }
 
 impl Config {
+    fn parse_should_ice(&self, line: &str) -> bool {
+        self.parse_name_directive(line, "should-ice")
+    }
     fn parse_error_pattern(&self, line: &str) -> Option<String> {
         self.parse_name_value_directive(line, "error-pattern")
     }

src/tools/compiletest/src/runtest.rs

@@ -383,7 +383,7 @@ impl<'test> TestCx<'test> {
     fn run_cfail_test(&self) {
         let proc_res = self.compile_test();
         self.check_if_test_should_compile(&proc_res);
-        self.check_no_compiler_crash(&proc_res);
+        self.check_no_compiler_crash(&proc_res, self.props.should_ice);
 
         let output_to_check = self.get_output(&proc_res);
         let expected_errors = errors::load_errors(&self.testpaths.file, self.revision);
@@ -395,6 +395,12 @@ impl<'test> TestCx<'test> {
         } else {
             self.check_error_patterns(&output_to_check, &proc_res);
         }
+        if self.props.should_ice {
+            match proc_res.status.code() {
+                Some(101) => (),
+                _ => self.fatal("expected ICE"),
+            }
+        }
 
         self.check_forbid_output(&output_to_check, &proc_res);
     }
@@ -428,7 +434,12 @@ impl<'test> TestCx<'test> {
     }
 
     fn check_correct_failure_status(&self, proc_res: &ProcRes) {
-        let expected_status = Some(self.props.failure_status);
+        let expected_status =
+            if self.props.should_ice {
+                Some(101)
+            } else {
+                Some(self.props.failure_status)
+            };
         let received_status = proc_res.status.code();
 
         if expected_status != received_status {
@@ -1402,9 +1413,11 @@ impl<'test> TestCx<'test> {
         }
     }
 
-    fn check_no_compiler_crash(&self, proc_res: &ProcRes) {
+    fn check_no_compiler_crash(&self, proc_res: &ProcRes, should_ice: bool) {
         match proc_res.status.code() {
-            Some(101) => self.fatal_proc_rec("compiler encountered internal error", proc_res),
+            Some(101) if !should_ice => {
+                self.fatal_proc_rec("compiler encountered internal error", proc_res)
+            }
             None => self.fatal_proc_rec("compiler terminated by signal", proc_res),
             _ => (),
         }
@@ -2518,7 +2531,7 @@ impl<'test> TestCx<'test> {
             self.fatal_proc_rec("compilation failed!", &proc_res);
         }
 
-        self.check_no_compiler_crash(&proc_res);
+        self.check_no_compiler_crash(&proc_res, self.props.should_ice);
 
         const PREFIX: &'static str = "MONO_ITEM ";
         const CGU_MARKER: &'static str = "@@";