From b4b7ccbd1ce1d794f4f9718ec0182b15591b73fa Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Sat, 3 Mar 2018 12:26:18 -0800
Subject: [PATCH 1/5] Add crate name to "main function not found" error
 message.

Fixes #44798 and rust-lang/cargo#4948.
---
 src/librustc/middle/entry.rs                          | 11 +++++++----
 src/librustc_driver/driver.rs                         |  2 +-
 src/test/ui/error-codes/E0522.stderr                  |  2 +-
 src/test/ui/feature-gate-i128_type2.stderr            |  2 +-
 .../feature-gate/issue-43106-gating-of-bench.stderr   |  2 +-
 .../feature-gate/issue-43106-gating-of-inline.stderr  |  2 +-
 .../issue-43106-gating-of-macro_escape.stderr         |  2 +-
 .../issue-43106-gating-of-proc_macro_derive.stderr    |  2 +-
 .../issue-43106-gating-of-rustc_deprecated.stderr     |  2 +-
 .../feature-gate/issue-43106-gating-of-stable.stderr  |  2 +-
 .../ui/feature-gate/issue-43106-gating-of-test.stderr |  2 +-
 .../issue-43106-gating-of-unstable.stderr             |  2 +-
 src/test/ui/generator/yield-in-const.stderr           |  2 +-
 src/test/ui/generator/yield-in-static.stderr          |  2 +-
 src/test/ui/imports/macro-paths.stderr                |  2 +-
 src/test/ui/imports/macros.stderr                     |  2 +-
 .../in-band-lifetimes/mismatched_trait_impl-2.stderr  |  2 +-
 src/test/ui/issue-47706-trait.stderr                  |  2 +-
 src/test/ui/main-wrong-location.stderr                |  2 +-
 src/test/ui/missing-items/m2.stderr                   |  2 +-
 src/test/ui/resolve/issue-14254.stderr                |  2 +-
 src/test/ui/resolve/issue-21221-2.stderr              |  2 +-
 .../suggest-path-instead-of-mod-dot-item.stderr       |  2 +-
 src/test/ui/span/issue-35987.stderr                   |  2 +-
 src/test/ui/token/issue-10636-2.stderr                |  2 +-
 src/test/ui/token/issue-41155.stderr                  |  2 +-
 26 files changed, 32 insertions(+), 29 deletions(-)

diff --git a/src/librustc/middle/entry.rs b/src/librustc/middle/entry.rs
index 8b4b9aaeac848..3473923c411fd 100644
--- a/src/librustc/middle/entry.rs
+++ b/src/librustc/middle/entry.rs
@@ -55,7 +55,9 @@ impl<'a, 'tcx> ItemLikeVisitor<'tcx> for EntryContext<'a, 'tcx> {
     }
 }
 
-pub fn find_entry_point(session: &Session, hir_map: &hir_map::Map) {
+pub fn find_entry_point(session: &Session,
+                        hir_map: &hir_map::Map,
+                        crate_name: &str) {
     let any_exe = session.crate_types.borrow().iter().any(|ty| {
         *ty == config::CrateTypeExecutable
     });
@@ -81,7 +83,7 @@ pub fn find_entry_point(session: &Session, hir_map: &hir_map::Map) {
 
     hir_map.krate().visit_all_item_likes(&mut ctxt);
 
-    configure_main(&mut ctxt);
+    configure_main(&mut ctxt, crate_name);
 }
 
 // Beware, this is duplicated in libsyntax/entry.rs, make sure to keep
@@ -150,7 +152,7 @@ fn find_item(item: &Item, ctxt: &mut EntryContext, at_root: bool) {
     }
 }
 
-fn configure_main(this: &mut EntryContext) {
+fn configure_main(this: &mut EntryContext, crate_name: &str) {
     if this.start_fn.is_some() {
         *this.session.entry_fn.borrow_mut() = this.start_fn;
         this.session.entry_type.set(Some(config::EntryStart));
@@ -162,7 +164,8 @@ fn configure_main(this: &mut EntryContext) {
         this.session.entry_type.set(Some(config::EntryMain));
     } else {
         // No main function
-        let mut err = struct_err!(this.session, E0601, "main function not found");
+        let mut err = struct_err!(this.session, E0601,
+            "main function not found in crate {}", crate_name);
         if !this.non_main_fns.is_empty() {
             // There were some functions named 'main' though. Try to give the user a hint.
             err.note("the main function must be defined at the crate level \
diff --git a/src/librustc_driver/driver.rs b/src/librustc_driver/driver.rs
index 542f818c3818a..e52575f02b2ff 100644
--- a/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@ -979,7 +979,7 @@ pub fn phase_3_run_analysis_passes<'tcx, F, R>(trans: &TransCrate,
 
     time(sess,
          "looking for entry point",
-         || middle::entry::find_entry_point(sess, &hir_map));
+         || middle::entry::find_entry_point(sess, &hir_map, name));
 
     sess.plugin_registrar_fn.set(time(sess, "looking for plugin registrar", || {
         plugin::build::find_plugin_registrar(sess.diagnostic(), &hir_map)
diff --git a/src/test/ui/error-codes/E0522.stderr b/src/test/ui/error-codes/E0522.stderr
index 5a6331bca0bde..31898312133ea 100644
--- a/src/test/ui/error-codes/E0522.stderr
+++ b/src/test/ui/error-codes/E0522.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate E0522
 
 error[E0522]: definition of an unknown language item: `cookie`
   --> $DIR/E0522.rs:13:1
diff --git a/src/test/ui/feature-gate-i128_type2.stderr b/src/test/ui/feature-gate-i128_type2.stderr
index 2348e7fe2c5b3..89b17ddbf0018 100644
--- a/src/test/ui/feature-gate-i128_type2.stderr
+++ b/src/test/ui/feature-gate-i128_type2.stderr
@@ -30,7 +30,7 @@ LL |     let x: u128 = 0; //~ ERROR 128-bit type is unstable
    |
    = help: add #![feature(i128_type)] to the crate attributes to enable
 
-error[E0601]: main function not found
+error[E0601]: main function not found in crate feature_gate_i128_type2
 
 error[E0658]: repr with 128-bit type is unstable (see issue #35118)
   --> $DIR/feature-gate-i128_type2.rs:30:1
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr
index f9f1cce91f1c7..27bf9c99652b0 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_43106_gating_of_bench
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-inline.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-inline.stderr
index 36320be1dc81f..68f3099ff7e1c 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-inline.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-inline.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_43106_gating_of_inline
 
 error[E0518]: attribute should be applied to function
   --> $DIR/issue-43106-gating-of-inline.rs:21:1
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.stderr
index d1d37720a55db..f8c1d9204af42 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.stderr
@@ -6,7 +6,7 @@ LL | #![macro_escape]
    |
    = help: consider an outer attribute, #[macro_use] mod ...
 
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_43106_gating_of_macro_escape
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.stderr
index c7654a3f258c9..de4ef084e4f22 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.stderr
@@ -34,7 +34,7 @@ error: the `#[proc_macro_derive]` attribute may only be used on bare functions
 LL |     #[proc_macro_derive = "2500"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_43106_gating_of_proc_macro_derive
 
 error: aborting due to 7 previous errors
 
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.stderr
index 5a1dd706ff3c9..af1e659d48c82 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_43106_gating_of_rustc_deprecated
 
 error: stability attributes may not be used outside of the standard library
   --> $DIR/issue-43106-gating-of-rustc_deprecated.rs:17:1
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-stable.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-stable.stderr
index bee9b8e968200..ebdaecc087825 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-stable.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-stable.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_43106_gating_of_stable
 
 error: stability attributes may not be used outside of the standard library
   --> $DIR/issue-43106-gating-of-stable.rs:17:1
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr
index f9f1cce91f1c7..0d35be76d9241 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_43106_gating_of_test
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-unstable.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-unstable.stderr
index 970cc2f2a349d..3da5f0cec92b8 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-unstable.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-unstable.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_43106_gating_of_unstable
 
 error: stability attributes may not be used outside of the standard library
   --> $DIR/issue-43106-gating-of-unstable.rs:17:1
diff --git a/src/test/ui/generator/yield-in-const.stderr b/src/test/ui/generator/yield-in-const.stderr
index 41a20893f5c46..f37a881a451f0 100644
--- a/src/test/ui/generator/yield-in-const.stderr
+++ b/src/test/ui/generator/yield-in-const.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate yield_in_const
 
 error[E0627]: yield statement outside of generator literal
   --> $DIR/yield-in-const.rs:13:17
diff --git a/src/test/ui/generator/yield-in-static.stderr b/src/test/ui/generator/yield-in-static.stderr
index 71ebc189035a5..0ade7a20cac8c 100644
--- a/src/test/ui/generator/yield-in-static.stderr
+++ b/src/test/ui/generator/yield-in-static.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate yield_in_static
 
 error[E0627]: yield statement outside of generator literal
   --> $DIR/yield-in-static.rs:13:18
diff --git a/src/test/ui/imports/macro-paths.stderr b/src/test/ui/imports/macro-paths.stderr
index 1422fb0904d0c..bf33bfaaf1fa0 100644
--- a/src/test/ui/imports/macro-paths.stderr
+++ b/src/test/ui/imports/macro-paths.stderr
@@ -36,7 +36,7 @@ LL | | }
    | |_^
    = note: macro-expanded items do not shadow when used in a macro invocation path
 
-error[E0601]: main function not found
+error[E0601]: main function not found in crate macro_paths
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/imports/macros.stderr b/src/test/ui/imports/macros.stderr
index d74020ecab298..c7a89df2a97a3 100644
--- a/src/test/ui/imports/macros.stderr
+++ b/src/test/ui/imports/macros.stderr
@@ -51,7 +51,7 @@ LL |     use two_macros::m;
    |         ^^^^^^^^^^^^^
    = note: macro-expanded macro imports do not shadow
 
-error[E0601]: main function not found
+error[E0601]: main function not found in crate macros
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr b/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr
index a3d05e72ed9f5..816a27086ccec 100644
--- a/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr
+++ b/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate mismatched_trait_impl_2
 
 error[E0495]: cannot infer an appropriate lifetime for lifetime parameter in generic type due to conflicting requirements
   --> $DIR/mismatched_trait_impl-2.rs:18:5
diff --git a/src/test/ui/issue-47706-trait.stderr b/src/test/ui/issue-47706-trait.stderr
index 542ba50178067..069ae9994a1a3 100644
--- a/src/test/ui/issue-47706-trait.stderr
+++ b/src/test/ui/issue-47706-trait.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_47706_trait
 
 error[E0593]: function is expected to take a single 0-tuple as argument, but it takes 2 distinct arguments
   --> $DIR/issue-47706-trait.rs:13:20
diff --git a/src/test/ui/main-wrong-location.stderr b/src/test/ui/main-wrong-location.stderr
index aad68de9ec794..c5affade5e214 100644
--- a/src/test/ui/main-wrong-location.stderr
+++ b/src/test/ui/main-wrong-location.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate main_wrong_location
    |
    = note: the main function must be defined at the crate level but you have one or more functions named 'main' that are not defined at the crate level. Either move the definition or attach the `#[main]` attribute to override this behavior.
 note: here is a function named 'main'
diff --git a/src/test/ui/missing-items/m2.stderr b/src/test/ui/missing-items/m2.stderr
index 1e4b47b44fabd..3b611518283bb 100644
--- a/src/test/ui/missing-items/m2.stderr
+++ b/src/test/ui/missing-items/m2.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found
+error[E0601]: main function not found in crate m2
 
 error[E0046]: not all trait items implemented, missing: `CONSTANT`, `Type`, `method`
   --> $DIR/m2.rs:19:1
diff --git a/src/test/ui/resolve/issue-14254.stderr b/src/test/ui/resolve/issue-14254.stderr
index 325e885084529..395ca412f3511 100644
--- a/src/test/ui/resolve/issue-14254.stderr
+++ b/src/test/ui/resolve/issue-14254.stderr
@@ -142,7 +142,7 @@ error[E0425]: cannot find value `bah` in this scope
 LL |         bah;
    |         ^^^ help: try: `Self::bah`
 
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_14254
 
 error: aborting due to 25 previous errors
 
diff --git a/src/test/ui/resolve/issue-21221-2.stderr b/src/test/ui/resolve/issue-21221-2.stderr
index 50781d4379272..fdafb509268ab 100644
--- a/src/test/ui/resolve/issue-21221-2.stderr
+++ b/src/test/ui/resolve/issue-21221-2.stderr
@@ -8,7 +8,7 @@ help: possible candidate is found in another module, you can import it into scop
 LL | use foo::bar::T;
    |
 
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_21221_2
 
 error: cannot continue compilation due to previous error
 
diff --git a/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.stderr b/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.stderr
index 263319f2ffa9e..e1a205e7b3ebf 100644
--- a/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.stderr
+++ b/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.stderr
@@ -72,7 +72,7 @@ LL |     a::b()
    |        |
    |        did you mean `I`?
 
-error[E0601]: main function not found
+error[E0601]: main function not found in crate suggest_path_instead_of_mod_dot_item
 
 error: aborting due to 10 previous errors
 
diff --git a/src/test/ui/span/issue-35987.stderr b/src/test/ui/span/issue-35987.stderr
index d3267d0cc1579..09d34f3d1afd8 100644
--- a/src/test/ui/span/issue-35987.stderr
+++ b/src/test/ui/span/issue-35987.stderr
@@ -8,7 +8,7 @@ help: possible better candidate is found in another module, you can import it in
 LL | use std::ops::Add;
    |
 
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_35987
 
 error: cannot continue compilation due to previous error
 
diff --git a/src/test/ui/token/issue-10636-2.stderr b/src/test/ui/token/issue-10636-2.stderr
index 4b672f31d3851..273cabb0474e6 100644
--- a/src/test/ui/token/issue-10636-2.stderr
+++ b/src/test/ui/token/issue-10636-2.stderr
@@ -22,7 +22,7 @@ error: expected expression, found `)`
 LL | } //~ ERROR: incorrect close delimiter
    | ^ expected expression
 
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_10636_2
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/token/issue-41155.stderr b/src/test/ui/token/issue-41155.stderr
index 00155cc28734a..80a4d43116f55 100644
--- a/src/test/ui/token/issue-41155.stderr
+++ b/src/test/ui/token/issue-41155.stderr
@@ -12,7 +12,7 @@ error[E0412]: cannot find type `S` in this scope
 LL | impl S { //~ ERROR cannot find type
    |      ^ not found in this scope
 
-error[E0601]: main function not found
+error[E0601]: main function not found in crate issue_41155
 
 error: aborting due to 3 previous errors
 

From 6aa4dcb9cf615ca4dd01b5f732d171103028c78b Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Mon, 12 Mar 2018 13:21:43 -0700
Subject: [PATCH 2/5] Add empty main() to tests where it is missing.

---
 src/test/ui/error-codes/E0522.rs                           | 2 ++
 src/test/ui/error-codes/E0522.stderr                       | 7 ++-----
 src/test/ui/feature-gate-i128_type2.rs                     | 2 ++
 src/test/ui/feature-gate-i128_type2.stderr                 | 7 ++-----
 src/test/ui/feature-gate/issue-43106-gating-of-inline.rs   | 2 ++
 .../ui/feature-gate/issue-43106-gating-of-inline.stderr    | 7 ++-----
 .../ui/feature-gate/issue-43106-gating-of-macro_escape.rs  | 4 ++++
 .../feature-gate/issue-43106-gating-of-macro_escape.stderr | 7 +------
 .../issue-43106-gating-of-proc_macro_derive.rs             | 2 ++
 .../issue-43106-gating-of-proc_macro_derive.stderr         | 5 +----
 .../feature-gate/issue-43106-gating-of-rustc_deprecated.rs | 1 +
 .../issue-43106-gating-of-rustc_deprecated.stderr          | 5 +----
 src/test/ui/feature-gate/issue-43106-gating-of-stable.rs   | 2 ++
 .../ui/feature-gate/issue-43106-gating-of-stable.stderr    | 5 +----
 src/test/ui/feature-gate/issue-43106-gating-of-unstable.rs | 2 ++
 .../ui/feature-gate/issue-43106-gating-of-unstable.stderr  | 5 +----
 src/test/ui/generator/yield-in-const.rs                    | 2 ++
 src/test/ui/generator/yield-in-const.stderr                | 7 ++-----
 src/test/ui/generator/yield-in-static.rs                   | 2 ++
 src/test/ui/generator/yield-in-static.stderr               | 7 ++-----
 src/test/ui/imports/macro-paths.rs                         | 2 ++
 src/test/ui/imports/macro-paths.stderr                     | 7 ++-----
 src/test/ui/imports/macros.rs                              | 2 ++
 src/test/ui/imports/macros.stderr                          | 7 ++-----
 src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.rs   | 2 ++
 .../ui/in-band-lifetimes/mismatched_trait_impl-2.stderr    | 7 ++-----
 src/test/ui/issue-47706-trait.rs                           | 2 ++
 src/test/ui/issue-47706-trait.stderr                       | 7 ++-----
 src/test/ui/missing-items/m2.rs                            | 2 ++
 src/test/ui/missing-items/m2.stderr                        | 7 ++-----
 src/test/ui/resolve/issue-14254.rs                         | 2 ++
 src/test/ui/resolve/issue-14254.stderr                     | 7 ++-----
 src/test/ui/resolve/issue-21221-2.rs                       | 2 ++
 src/test/ui/resolve/issue-21221-2.stderr                   | 2 --
 .../ui/resolve/suggest-path-instead-of-mod-dot-item.rs     | 2 ++
 .../ui/resolve/suggest-path-instead-of-mod-dot-item.stderr | 7 ++-----
 src/test/ui/span/issue-35987.rs                            | 2 ++
 src/test/ui/span/issue-35987.stderr                        | 2 --
 src/test/ui/token/issue-10636-2.rs                         | 2 ++
 src/test/ui/token/issue-10636-2.stderr                     | 5 +----
 src/test/ui/token/issue-41155.rs                           | 2 ++
 src/test/ui/token/issue-41155.stderr                       | 7 ++-----
 42 files changed, 75 insertions(+), 95 deletions(-)

diff --git a/src/test/ui/error-codes/E0522.rs b/src/test/ui/error-codes/E0522.rs
index 3d4377853464b..c50cb759e05c2 100644
--- a/src/test/ui/error-codes/E0522.rs
+++ b/src/test/ui/error-codes/E0522.rs
@@ -15,3 +15,5 @@ fn cookie() -> ! {
 //~^^ ERROR definition of an unknown language item: `cookie` [E0522]
     loop {}
 }
+
+fn main() {}
diff --git a/src/test/ui/error-codes/E0522.stderr b/src/test/ui/error-codes/E0522.stderr
index 31898312133ea..9f3f8968d734e 100644
--- a/src/test/ui/error-codes/E0522.stderr
+++ b/src/test/ui/error-codes/E0522.stderr
@@ -1,12 +1,9 @@
-error[E0601]: main function not found in crate E0522
-
 error[E0522]: definition of an unknown language item: `cookie`
   --> $DIR/E0522.rs:13:1
    |
 LL | #[lang = "cookie"]
    | ^^^^^^^^^^^^^^^^^^ definition of unknown language item `cookie`
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors occurred: E0522, E0601.
-For more information about an error, try `rustc --explain E0522`.
+For more information about this error, try `rustc --explain E0522`.
diff --git a/src/test/ui/feature-gate-i128_type2.rs b/src/test/ui/feature-gate-i128_type2.rs
index d3bd810ceb2b4..8a7d316ed8384 100644
--- a/src/test/ui/feature-gate-i128_type2.rs
+++ b/src/test/ui/feature-gate-i128_type2.rs
@@ -30,3 +30,5 @@ fn test3_2() {
 enum A { //~ ERROR 128-bit type is unstable
     A(u64)
 }
+
+fn main() {}
diff --git a/src/test/ui/feature-gate-i128_type2.stderr b/src/test/ui/feature-gate-i128_type2.stderr
index 89b17ddbf0018..23d4d6c98d90a 100644
--- a/src/test/ui/feature-gate-i128_type2.stderr
+++ b/src/test/ui/feature-gate-i128_type2.stderr
@@ -30,8 +30,6 @@ LL |     let x: u128 = 0; //~ ERROR 128-bit type is unstable
    |
    = help: add #![feature(i128_type)] to the crate attributes to enable
 
-error[E0601]: main function not found in crate feature_gate_i128_type2
-
 error[E0658]: repr with 128-bit type is unstable (see issue #35118)
   --> $DIR/feature-gate-i128_type2.rs:30:1
    |
@@ -42,7 +40,6 @@ LL | | }
    |
    = help: add #![feature(repr128)] to the crate attributes to enable
 
-error: aborting due to 6 previous errors
+error: aborting due to 5 previous errors
 
-Some errors occurred: E0601, E0658.
-For more information about an error, try `rustc --explain E0601`.
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-inline.rs b/src/test/ui/feature-gate/issue-43106-gating-of-inline.rs
index 24e77bf60a8d1..410f960e655fb 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-inline.rs
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-inline.rs
@@ -35,3 +35,5 @@ mod inline {
     #[inline = "2100"] impl S { }
     //~^ ERROR attribute should be applied to function
 }
+
+fn main() {}
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-inline.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-inline.stderr
index 68f3099ff7e1c..d67d78e31a9d5 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-inline.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-inline.stderr
@@ -1,5 +1,3 @@
-error[E0601]: main function not found in crate issue_43106_gating_of_inline
-
 error[E0518]: attribute should be applied to function
   --> $DIR/issue-43106-gating-of-inline.rs:21:1
    |
@@ -39,7 +37,6 @@ error[E0518]: attribute should be applied to function
 LL |     #[inline = "2100"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^ ---------- not a function
 
-error: aborting due to 6 previous errors
+error: aborting due to 5 previous errors
 
-Some errors occurred: E0518, E0601.
-For more information about an error, try `rustc --explain E0518`.
+For more information about this error, try `rustc --explain E0518`.
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.rs b/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.rs
index 3b2dbdefebad8..ec3c97beab0f3 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.rs
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.rs
@@ -13,5 +13,9 @@
 // `#![macro_escape]` is incompatible with crate-level `#![macro_use]`
 // already present in issue-43106-gating-of-builtin-attrs.
 
+// must-compile-successfully
+
 #![macro_escape]
 //~^ WARN macro_escape is a deprecated synonym for macro_use
+
+fn main() {}
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.stderr
index f8c1d9204af42..d19720397e66d 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-macro_escape.stderr
@@ -1,13 +1,8 @@
 warning: macro_escape is a deprecated synonym for macro_use
-  --> $DIR/issue-43106-gating-of-macro_escape.rs:16:1
+  --> $DIR/issue-43106-gating-of-macro_escape.rs:18:1
    |
 LL | #![macro_escape]
    | ^^^^^^^^^^^^^^^^
    |
    = help: consider an outer attribute, #[macro_use] mod ...
 
-error[E0601]: main function not found in crate issue_43106_gating_of_macro_escape
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0601`.
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.rs b/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.rs
index 133f70e0f3b19..5bb8bb024ed51 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.rs
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.rs
@@ -40,3 +40,5 @@ mod proc_macro_derive2 {
     #[proc_macro_derive = "2500"] impl S { }
     //~^ ERROR the `#[proc_macro_derive]` attribute may only be used on bare functions
 }
+
+fn main() {}
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.stderr
index de4ef084e4f22..419efb6825a97 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-proc_macro_derive.stderr
@@ -34,8 +34,5 @@ error: the `#[proc_macro_derive]` attribute may only be used on bare functions
 LL |     #[proc_macro_derive = "2500"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0601]: main function not found in crate issue_43106_gating_of_proc_macro_derive
+error: aborting due to 6 previous errors
 
-error: aborting due to 7 previous errors
-
-For more information about this error, try `rustc --explain E0601`.
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.rs b/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.rs
index 10c1398634923..0c6cfb5da565c 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.rs
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.rs
@@ -36,3 +36,4 @@ mod rustc_deprecated {
     //~^ ERROR stability attributes may not be used outside of the standard library
 }
 
+fn main() {}
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.stderr
index af1e659d48c82..35c15cb6b1ea8 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-rustc_deprecated.stderr
@@ -1,5 +1,3 @@
-error[E0601]: main function not found in crate issue_43106_gating_of_rustc_deprecated
-
 error: stability attributes may not be used outside of the standard library
   --> $DIR/issue-43106-gating-of-rustc_deprecated.rs:17:1
    |
@@ -42,6 +40,5 @@ error: stability attributes may not be used outside of the standard library
 LL |     #[rustc_deprecated = "1500"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 8 previous errors
+error: aborting due to 7 previous errors
 
-For more information about this error, try `rustc --explain E0601`.
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-stable.rs b/src/test/ui/feature-gate/issue-43106-gating-of-stable.rs
index a6eaabf7a383e..6415243d0873e 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-stable.rs
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-stable.rs
@@ -35,3 +35,5 @@ mod stable {
     #[stable = "1300"] impl S { }
     //~^ ERROR stability attributes may not be used outside of the standard library
 }
+
+fn main() {}
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-stable.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-stable.stderr
index ebdaecc087825..21543d1b20afc 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-stable.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-stable.stderr
@@ -1,5 +1,3 @@
-error[E0601]: main function not found in crate issue_43106_gating_of_stable
-
 error: stability attributes may not be used outside of the standard library
   --> $DIR/issue-43106-gating-of-stable.rs:17:1
    |
@@ -42,6 +40,5 @@ error: stability attributes may not be used outside of the standard library
 LL |     #[stable = "1300"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 8 previous errors
+error: aborting due to 7 previous errors
 
-For more information about this error, try `rustc --explain E0601`.
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-unstable.rs b/src/test/ui/feature-gate/issue-43106-gating-of-unstable.rs
index ff0600deb1936..140474d82c88d 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-unstable.rs
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-unstable.rs
@@ -35,3 +35,5 @@ mod unstable {
     #[unstable = "1200"] impl S { }
     //~^ ERROR stability attributes may not be used outside of the standard library
 }
+
+fn main() {}
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-unstable.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-unstable.stderr
index 3da5f0cec92b8..6124e16f41804 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-unstable.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-unstable.stderr
@@ -1,5 +1,3 @@
-error[E0601]: main function not found in crate issue_43106_gating_of_unstable
-
 error: stability attributes may not be used outside of the standard library
   --> $DIR/issue-43106-gating-of-unstable.rs:17:1
    |
@@ -42,6 +40,5 @@ error: stability attributes may not be used outside of the standard library
 LL |     #[unstable = "1200"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 8 previous errors
+error: aborting due to 7 previous errors
 
-For more information about this error, try `rustc --explain E0601`.
diff --git a/src/test/ui/generator/yield-in-const.rs b/src/test/ui/generator/yield-in-const.rs
index e166d26515975..8636a66ae00ae 100644
--- a/src/test/ui/generator/yield-in-const.rs
+++ b/src/test/ui/generator/yield-in-const.rs
@@ -12,3 +12,5 @@
 
 const A: u8 = { yield 3u8; 3u8};
 //~^ ERROR yield statement outside
+
+fn main() {}
diff --git a/src/test/ui/generator/yield-in-const.stderr b/src/test/ui/generator/yield-in-const.stderr
index f37a881a451f0..874edce593168 100644
--- a/src/test/ui/generator/yield-in-const.stderr
+++ b/src/test/ui/generator/yield-in-const.stderr
@@ -1,12 +1,9 @@
-error[E0601]: main function not found in crate yield_in_const
-
 error[E0627]: yield statement outside of generator literal
   --> $DIR/yield-in-const.rs:13:17
    |
 LL | const A: u8 = { yield 3u8; 3u8};
    |                 ^^^^^^^^^
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors occurred: E0601, E0627.
-For more information about an error, try `rustc --explain E0601`.
+For more information about this error, try `rustc --explain E0627`.
diff --git a/src/test/ui/generator/yield-in-static.rs b/src/test/ui/generator/yield-in-static.rs
index 823a2aa425e2c..21601f47f677d 100644
--- a/src/test/ui/generator/yield-in-static.rs
+++ b/src/test/ui/generator/yield-in-static.rs
@@ -12,3 +12,5 @@
 
 static B: u8 = { yield 3u8; 3u8};
 //~^ ERROR yield statement outside
+
+fn main() {}
diff --git a/src/test/ui/generator/yield-in-static.stderr b/src/test/ui/generator/yield-in-static.stderr
index 0ade7a20cac8c..35d1ebaabdc1c 100644
--- a/src/test/ui/generator/yield-in-static.stderr
+++ b/src/test/ui/generator/yield-in-static.stderr
@@ -1,12 +1,9 @@
-error[E0601]: main function not found in crate yield_in_static
-
 error[E0627]: yield statement outside of generator literal
   --> $DIR/yield-in-static.rs:13:18
    |
 LL | static B: u8 = { yield 3u8; 3u8};
    |                  ^^^^^^^^^
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors occurred: E0601, E0627.
-For more information about an error, try `rustc --explain E0601`.
+For more information about this error, try `rustc --explain E0627`.
diff --git a/src/test/ui/imports/macro-paths.rs b/src/test/ui/imports/macro-paths.rs
index 88a6e1c0d92e6..e709eeee14a84 100644
--- a/src/test/ui/imports/macro-paths.rs
+++ b/src/test/ui/imports/macro-paths.rs
@@ -36,3 +36,5 @@ fn g() {
         mod baz { pub use two_macros::m; }
     }
 }
+
+fn main() {}
diff --git a/src/test/ui/imports/macro-paths.stderr b/src/test/ui/imports/macro-paths.stderr
index bf33bfaaf1fa0..799e7f972464b 100644
--- a/src/test/ui/imports/macro-paths.stderr
+++ b/src/test/ui/imports/macro-paths.stderr
@@ -36,9 +36,6 @@ LL | | }
    | |_^
    = note: macro-expanded items do not shadow when used in a macro invocation path
 
-error[E0601]: main function not found in crate macro_paths
+error: aborting due to 2 previous errors
 
-error: aborting due to 3 previous errors
-
-Some errors occurred: E0601, E0659.
-For more information about an error, try `rustc --explain E0601`.
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/imports/macros.rs b/src/test/ui/imports/macros.rs
index 98577d73ee0f6..5d6a11913849a 100644
--- a/src/test/ui/imports/macros.rs
+++ b/src/test/ui/imports/macros.rs
@@ -49,3 +49,5 @@ mod m4 {
     use two_macros::m;
     m!(); //~ ERROR ambiguous
 }
+
+fn main() {}
diff --git a/src/test/ui/imports/macros.stderr b/src/test/ui/imports/macros.stderr
index c7a89df2a97a3..f91987cd9f340 100644
--- a/src/test/ui/imports/macros.stderr
+++ b/src/test/ui/imports/macros.stderr
@@ -51,9 +51,6 @@ LL |     use two_macros::m;
    |         ^^^^^^^^^^^^^
    = note: macro-expanded macro imports do not shadow
 
-error[E0601]: main function not found in crate macros
+error: aborting due to 3 previous errors
 
-error: aborting due to 4 previous errors
-
-Some errors occurred: E0601, E0659.
-For more information about an error, try `rustc --explain E0601`.
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.rs b/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.rs
index f845762cefd8b..ff04cfe99c0bc 100644
--- a/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.rs
+++ b/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.rs
@@ -20,3 +20,5 @@ impl Deref for Struct {
     }
 }
 //~^^^^ ERROR cannot infer an appropriate lifetime for lifetime parameter
+
+fn main() {}
diff --git a/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr b/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr
index 816a27086ccec..37b586e1e3bd0 100644
--- a/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr
+++ b/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr
@@ -1,5 +1,3 @@
-error[E0601]: main function not found in crate mismatched_trait_impl_2
-
 error[E0495]: cannot infer an appropriate lifetime for lifetime parameter in generic type due to conflicting requirements
   --> $DIR/mismatched_trait_impl-2.rs:18:5
    |
@@ -18,7 +16,6 @@ LL | |     }
            expected fn(&Struct) -> &Trait + 'static
               found fn(&Struct) -> &Trait
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors occurred: E0495, E0601.
-For more information about an error, try `rustc --explain E0495`.
+For more information about this error, try `rustc --explain E0495`.
diff --git a/src/test/ui/issue-47706-trait.rs b/src/test/ui/issue-47706-trait.rs
index 86a9da49a054a..4ce653547da03 100644
--- a/src/test/ui/issue-47706-trait.rs
+++ b/src/test/ui/issue-47706-trait.rs
@@ -14,3 +14,5 @@ trait T {
     }
     //~^^ ERROR function is expected to take a single 0-tuple as argument
 }
+
+fn main() {}
diff --git a/src/test/ui/issue-47706-trait.stderr b/src/test/ui/issue-47706-trait.stderr
index 069ae9994a1a3..717b3eb0b5625 100644
--- a/src/test/ui/issue-47706-trait.stderr
+++ b/src/test/ui/issue-47706-trait.stderr
@@ -1,5 +1,3 @@
-error[E0601]: main function not found in crate issue_47706_trait
-
 error[E0593]: function is expected to take a single 0-tuple as argument, but it takes 2 distinct arguments
   --> $DIR/issue-47706-trait.rs:13:20
    |
@@ -8,7 +6,6 @@ LL |     fn f(&self, _: ()) {
 LL |         None::<()>.map(Self::f);
    |                    ^^^ expected function that takes a single 0-tuple as argument
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors occurred: E0593, E0601.
-For more information about an error, try `rustc --explain E0593`.
+For more information about this error, try `rustc --explain E0593`.
diff --git a/src/test/ui/missing-items/m2.rs b/src/test/ui/missing-items/m2.rs
index 9f1954526916f..f655047f6f5ac 100644
--- a/src/test/ui/missing-items/m2.rs
+++ b/src/test/ui/missing-items/m2.rs
@@ -18,3 +18,5 @@ struct X {
 
 impl m1::X for X { //~ ERROR not all trait items implemented
 }
+
+fn main() {}
diff --git a/src/test/ui/missing-items/m2.stderr b/src/test/ui/missing-items/m2.stderr
index 3b611518283bb..3f7a4039eb76b 100644
--- a/src/test/ui/missing-items/m2.stderr
+++ b/src/test/ui/missing-items/m2.stderr
@@ -1,5 +1,3 @@
-error[E0601]: main function not found in crate m2
-
 error[E0046]: not all trait items implemented, missing: `CONSTANT`, `Type`, `method`
   --> $DIR/m2.rs:19:1
    |
@@ -10,7 +8,6 @@ LL | impl m1::X for X { //~ ERROR not all trait items implemented
    = note: `Type` from trait: `type Type;`
    = note: `method` from trait: `fn(&Self, std::string::String) -> <Self as m1::X>::Type`
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors occurred: E0046, E0601.
-For more information about an error, try `rustc --explain E0046`.
+For more information about this error, try `rustc --explain E0046`.
diff --git a/src/test/ui/resolve/issue-14254.rs b/src/test/ui/resolve/issue-14254.rs
index 896085329ab94..eab500de25569 100644
--- a/src/test/ui/resolve/issue-14254.rs
+++ b/src/test/ui/resolve/issue-14254.rs
@@ -111,3 +111,5 @@ impl Foo for Box<isize> {
         //~^ ERROR cannot find value `bah`
     }
 }
+
+fn main() {}
diff --git a/src/test/ui/resolve/issue-14254.stderr b/src/test/ui/resolve/issue-14254.stderr
index 395ca412f3511..055cbb2d57916 100644
--- a/src/test/ui/resolve/issue-14254.stderr
+++ b/src/test/ui/resolve/issue-14254.stderr
@@ -142,9 +142,6 @@ error[E0425]: cannot find value `bah` in this scope
 LL |         bah;
    |         ^^^ help: try: `Self::bah`
 
-error[E0601]: main function not found in crate issue_14254
+error: aborting due to 24 previous errors
 
-error: aborting due to 25 previous errors
-
-Some errors occurred: E0425, E0601.
-For more information about an error, try `rustc --explain E0425`.
+For more information about this error, try `rustc --explain E0425`.
diff --git a/src/test/ui/resolve/issue-21221-2.rs b/src/test/ui/resolve/issue-21221-2.rs
index 4ddb4d669fcd2..361e8caf7442e 100644
--- a/src/test/ui/resolve/issue-21221-2.rs
+++ b/src/test/ui/resolve/issue-21221-2.rs
@@ -27,3 +27,5 @@ pub mod baz {
 struct Foo;
 impl T for Foo { }
 //~^ ERROR cannot find trait `T`
+
+fn main() {}
diff --git a/src/test/ui/resolve/issue-21221-2.stderr b/src/test/ui/resolve/issue-21221-2.stderr
index fdafb509268ab..c61ffe3b33e8a 100644
--- a/src/test/ui/resolve/issue-21221-2.stderr
+++ b/src/test/ui/resolve/issue-21221-2.stderr
@@ -8,7 +8,5 @@ help: possible candidate is found in another module, you can import it into scop
 LL | use foo::bar::T;
    |
 
-error[E0601]: main function not found in crate issue_21221_2
-
 error: cannot continue compilation due to previous error
 
diff --git a/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.rs b/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.rs
index 981a853a04056..d24fced5d313f 100644
--- a/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.rs
+++ b/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.rs
@@ -65,3 +65,5 @@ fn h8() -> i32 {
     a::b()
     //~^ ERROR expected function, found module `a::b`
 }
+
+fn main() {}
diff --git a/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.stderr b/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.stderr
index e1a205e7b3ebf..9216c0b321929 100644
--- a/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.stderr
+++ b/src/test/ui/resolve/suggest-path-instead-of-mod-dot-item.stderr
@@ -72,9 +72,6 @@ LL |     a::b()
    |        |
    |        did you mean `I`?
 
-error[E0601]: main function not found in crate suggest_path_instead_of_mod_dot_item
+error: aborting due to 9 previous errors
 
-error: aborting due to 10 previous errors
-
-Some errors occurred: E0423, E0601.
-For more information about an error, try `rustc --explain E0423`.
+For more information about this error, try `rustc --explain E0423`.
diff --git a/src/test/ui/span/issue-35987.rs b/src/test/ui/span/issue-35987.rs
index fa0410686c26c..19e05f33825f7 100644
--- a/src/test/ui/span/issue-35987.rs
+++ b/src/test/ui/span/issue-35987.rs
@@ -20,3 +20,5 @@ impl<T: Clone, Add> Add for Foo<T> {
         unimplemented!();
     }
 }
+
+fn main() {}
diff --git a/src/test/ui/span/issue-35987.stderr b/src/test/ui/span/issue-35987.stderr
index 09d34f3d1afd8..2d4a7cc72f5f6 100644
--- a/src/test/ui/span/issue-35987.stderr
+++ b/src/test/ui/span/issue-35987.stderr
@@ -8,7 +8,5 @@ help: possible better candidate is found in another module, you can import it in
 LL | use std::ops::Add;
    |
 
-error[E0601]: main function not found in crate issue_35987
-
 error: cannot continue compilation due to previous error
 
diff --git a/src/test/ui/token/issue-10636-2.rs b/src/test/ui/token/issue-10636-2.rs
index 4aa4127019378..711803754408f 100644
--- a/src/test/ui/token/issue-10636-2.rs
+++ b/src/test/ui/token/issue-10636-2.rs
@@ -17,3 +17,5 @@ pub fn trace_option(option: Option<isize>) {
 
 } //~ ERROR: incorrect close delimiter
 //~^ ERROR: expected expression, found `)`
+
+fn main() {}
diff --git a/src/test/ui/token/issue-10636-2.stderr b/src/test/ui/token/issue-10636-2.stderr
index 273cabb0474e6..56a30423171da 100644
--- a/src/test/ui/token/issue-10636-2.stderr
+++ b/src/test/ui/token/issue-10636-2.stderr
@@ -22,8 +22,5 @@ error: expected expression, found `)`
 LL | } //~ ERROR: incorrect close delimiter
    | ^ expected expression
 
-error[E0601]: main function not found in crate issue_10636_2
+error: aborting due to 3 previous errors
 
-error: aborting due to 4 previous errors
-
-For more information about this error, try `rustc --explain E0601`.
diff --git a/src/test/ui/token/issue-41155.rs b/src/test/ui/token/issue-41155.rs
index 550a90fc6af26..7bd8506af90b9 100644
--- a/src/test/ui/token/issue-41155.rs
+++ b/src/test/ui/token/issue-41155.rs
@@ -11,3 +11,5 @@
 impl S { //~ ERROR cannot find type
     pub
 } //~ ERROR expected one of
+
+fn main() {}
diff --git a/src/test/ui/token/issue-41155.stderr b/src/test/ui/token/issue-41155.stderr
index 80a4d43116f55..b56b95a8aafd7 100644
--- a/src/test/ui/token/issue-41155.stderr
+++ b/src/test/ui/token/issue-41155.stderr
@@ -12,9 +12,6 @@ error[E0412]: cannot find type `S` in this scope
 LL | impl S { //~ ERROR cannot find type
    |      ^ not found in this scope
 
-error[E0601]: main function not found in crate issue_41155
+error: aborting due to 2 previous errors
 
-error: aborting due to 3 previous errors
-
-Some errors occurred: E0412, E0601.
-For more information about an error, try `rustc --explain E0412`.
+For more information about this error, try `rustc --explain E0412`.

From b08e6d305f8366c8fa7e08d829bb0c6939124759 Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Mon, 12 Mar 2018 13:23:12 -0700
Subject: [PATCH 3/5] Add suggestion where to add main function.

---
 src/librustc/middle/entry.rs                          |  3 +++
 src/test/ui/error-codes/E0601.rs                      | 11 +++++++++++
 src/test/ui/error-codes/E0601.stderr                  |  7 +++++++
 .../feature-gate/issue-43106-gating-of-bench.stderr   |  2 ++
 .../ui/feature-gate/issue-43106-gating-of-test.stderr |  2 ++
 5 files changed, 25 insertions(+)
 create mode 100644 src/test/ui/error-codes/E0601.rs
 create mode 100644 src/test/ui/error-codes/E0601.stderr

diff --git a/src/librustc/middle/entry.rs b/src/librustc/middle/entry.rs
index 3473923c411fd..8193aad762730 100644
--- a/src/librustc/middle/entry.rs
+++ b/src/librustc/middle/entry.rs
@@ -178,6 +178,9 @@ fn configure_main(this: &mut EntryContext, crate_name: &str) {
             err.emit();
             this.session.abort_if_errors();
         } else {
+            if let Some(ref filename) = this.session.local_crate_source_file {
+                err.note(&format!("consider adding a main function to {}", filename.display()));
+            }
             if this.session.teach(&err.get_code().unwrap()) {
                 err.note("If you don't know the basics of Rust, you can go look to the Rust Book \
                           to get started: https://doc.rust-lang.org/book/");
diff --git a/src/test/ui/error-codes/E0601.rs b/src/test/ui/error-codes/E0601.rs
new file mode 100644
index 0000000000000..37b3f523475fc
--- /dev/null
+++ b/src/test/ui/error-codes/E0601.rs
@@ -0,0 +1,11 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test for main function not found.
diff --git a/src/test/ui/error-codes/E0601.stderr b/src/test/ui/error-codes/E0601.stderr
new file mode 100644
index 0000000000000..eff0a3299020d
--- /dev/null
+++ b/src/test/ui/error-codes/E0601.stderr
@@ -0,0 +1,7 @@
+error[E0601]: main function not found in crate E0601
+   |
+   = note: consider adding a main function to $DIR/E0601.rs
+
+error: aborting due to previous error
+
+If you want more information on this error, try using "rustc --explain E0601"
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr
index 27bf9c99652b0..32ee8026197b7 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr
@@ -1,4 +1,6 @@
 error[E0601]: main function not found in crate issue_43106_gating_of_bench
+   |
+   = note: consider adding a main function to $DIR/issue-43106-gating-of-bench.rs
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr
index 0d35be76d9241..b86dd834d9a04 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr
@@ -1,4 +1,6 @@
 error[E0601]: main function not found in crate issue_43106_gating_of_test
+   |
+   = note: consider adding a main function to $DIR/issue-43106-gating-of-test.rs
 
 error: aborting due to previous error
 

From 2f1b34cc15d9ce8daecfb7855957a36e6e10f2e5 Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Tue, 13 Mar 2018 11:22:43 -0700
Subject: [PATCH 4/5] Add backticks to `main` not found errors.

---
 src/librustc/middle/entry.rs                                | 4 ++--
 src/test/compile-fail/cfg-attr-cfg-2.rs                     | 2 +-
 src/test/compile-fail/cfg-in-crate-1.rs                     | 2 +-
 src/test/compile-fail/elided-test.rs                        | 2 +-
 src/test/compile-fail/missing-main.rs                       | 2 +-
 src/test/ui/error-codes/E0601.stderr                        | 4 ++--
 src/test/ui/feature-gate/issue-43106-gating-of-bench.rs     | 2 +-
 src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr | 4 ++--
 src/test/ui/feature-gate/issue-43106-gating-of-test.rs      | 2 +-
 src/test/ui/feature-gate/issue-43106-gating-of-test.stderr  | 4 ++--
 src/test/ui/main-wrong-location.stderr                      | 2 +-
 11 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/src/librustc/middle/entry.rs b/src/librustc/middle/entry.rs
index 8193aad762730..37d79f408f3f0 100644
--- a/src/librustc/middle/entry.rs
+++ b/src/librustc/middle/entry.rs
@@ -165,7 +165,7 @@ fn configure_main(this: &mut EntryContext, crate_name: &str) {
     } else {
         // No main function
         let mut err = struct_err!(this.session, E0601,
-            "main function not found in crate {}", crate_name);
+            "`main` function not found in crate `{}`", crate_name);
         if !this.non_main_fns.is_empty() {
             // There were some functions named 'main' though. Try to give the user a hint.
             err.note("the main function must be defined at the crate level \
@@ -179,7 +179,7 @@ fn configure_main(this: &mut EntryContext, crate_name: &str) {
             this.session.abort_if_errors();
         } else {
             if let Some(ref filename) = this.session.local_crate_source_file {
-                err.note(&format!("consider adding a main function to {}", filename.display()));
+                err.note(&format!("consider adding a `main` function to `{}`", filename.display()));
             }
             if this.session.teach(&err.get_code().unwrap()) {
                 err.note("If you don't know the basics of Rust, you can go look to the Rust Book \
diff --git a/src/test/compile-fail/cfg-attr-cfg-2.rs b/src/test/compile-fail/cfg-attr-cfg-2.rs
index b71a3be5dcea4..58a62d45ea5d7 100644
--- a/src/test/compile-fail/cfg-attr-cfg-2.rs
+++ b/src/test/compile-fail/cfg-attr-cfg-2.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 //
-// error-pattern: main function not found
+// error-pattern: `main` function not found
 // compile-flags: --cfg foo
 
 // main is conditionally compiled, but the conditional compilation
diff --git a/src/test/compile-fail/cfg-in-crate-1.rs b/src/test/compile-fail/cfg-in-crate-1.rs
index 94ae8d89b4fc4..bbccf2bcd0f81 100644
--- a/src/test/compile-fail/cfg-in-crate-1.rs
+++ b/src/test/compile-fail/cfg-in-crate-1.rs
@@ -8,6 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:main function not found
+// error-pattern: `main` function not found
 
 #![cfg(bar)]
diff --git a/src/test/compile-fail/elided-test.rs b/src/test/compile-fail/elided-test.rs
index b62214b12f9a0..0cdd0010a745d 100644
--- a/src/test/compile-fail/elided-test.rs
+++ b/src/test/compile-fail/elided-test.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern: main function not found
+// error-pattern: `main` function not found
 
 // Since we're not compiling a test runner this function should be elided
 // and the build will fail because main doesn't exist
diff --git a/src/test/compile-fail/missing-main.rs b/src/test/compile-fail/missing-main.rs
index 4bfdaf69480e6..2788a5c2d5854 100644
--- a/src/test/compile-fail/missing-main.rs
+++ b/src/test/compile-fail/missing-main.rs
@@ -8,5 +8,5 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:main function not found
+// error-pattern: `main` function not found
 fn mian() { }
diff --git a/src/test/ui/error-codes/E0601.stderr b/src/test/ui/error-codes/E0601.stderr
index eff0a3299020d..6fe05d2dc8e03 100644
--- a/src/test/ui/error-codes/E0601.stderr
+++ b/src/test/ui/error-codes/E0601.stderr
@@ -1,6 +1,6 @@
-error[E0601]: main function not found in crate E0601
+error[E0601]: `main` function not found in crate `E0601`
    |
-   = note: consider adding a main function to $DIR/E0601.rs
+   = note: consider adding a `main` function to `$DIR/E0601.rs`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-bench.rs b/src/test/ui/feature-gate/issue-43106-gating-of-bench.rs
index a34f98f03559f..6c22679933874 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-bench.rs
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-bench.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern: main function not found
+// error-pattern: `main` function not found
 
 // At time of authorship, a crate-level #![bench] with no `--test`
 // will cause compilation to error unconditionally with "main function
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr
index 32ee8026197b7..503ef020d9604 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-bench.stderr
@@ -1,6 +1,6 @@
-error[E0601]: main function not found in crate issue_43106_gating_of_bench
+error[E0601]: `main` function not found in crate `issue_43106_gating_of_bench`
    |
-   = note: consider adding a main function to $DIR/issue-43106-gating-of-bench.rs
+   = note: consider adding a `main` function to `$DIR/issue-43106-gating-of-bench.rs`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-test.rs b/src/test/ui/feature-gate/issue-43106-gating-of-test.rs
index adcbfe77280b7..06632396249a5 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-test.rs
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-test.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern: main function not found
+// error-pattern: `main` function not found
 
 // At time of authorship, crate-level #[test] attribute with no
 // `--test` signals unconditional error complaining of missing main
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr
index b86dd834d9a04..2ab35be43c576 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-test.stderr
@@ -1,6 +1,6 @@
-error[E0601]: main function not found in crate issue_43106_gating_of_test
+error[E0601]: `main` function not found in crate `issue_43106_gating_of_test`
    |
-   = note: consider adding a main function to $DIR/issue-43106-gating-of-test.rs
+   = note: consider adding a `main` function to `$DIR/issue-43106-gating-of-test.rs`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/main-wrong-location.stderr b/src/test/ui/main-wrong-location.stderr
index c5affade5e214..a5ef92f14bbc5 100644
--- a/src/test/ui/main-wrong-location.stderr
+++ b/src/test/ui/main-wrong-location.stderr
@@ -1,4 +1,4 @@
-error[E0601]: main function not found in crate main_wrong_location
+error[E0601]: `main` function not found in crate `main_wrong_location`
    |
    = note: the main function must be defined at the crate level but you have one or more functions named 'main' that are not defined at the crate level. Either move the definition or attach the `#[main]` attribute to override this behavior.
 note: here is a function named 'main'

From 525727529492f30ef9d68467d5b8a7f18f65d743 Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Wed, 14 Mar 2018 13:04:24 -0700
Subject: [PATCH 5/5] Update E0601 test for new message format.

---
 src/test/ui/error-codes/E0601.stderr | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/test/ui/error-codes/E0601.stderr b/src/test/ui/error-codes/E0601.stderr
index 6fe05d2dc8e03..cbc20db35da77 100644
--- a/src/test/ui/error-codes/E0601.stderr
+++ b/src/test/ui/error-codes/E0601.stderr
@@ -4,4 +4,4 @@ error[E0601]: `main` function not found in crate `E0601`
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0601"
+For more information about this error, try `rustc --explain E0601`.