Provide a span if main function is not present in crate

Unfortunately, the diagnotic machinery does not cope well with an empty
span which can happen if the crate is empty, in which case we merely set
a spanless note.

7 files changed, 28 insertions, 19 deletions

diff --git a/src/test/ui/parser/issue-2354.rs b/src/test/ui/parser/issue-2354.rs
index 565f84822f7..a14eb6e32fc 100644
--- a/src/test/ui/parser/issue-2354.rs
+++ b/src/test/ui/parser/issue-2354.rs
@@ -1,4 +1,7 @@
 fn foo() { //~ NOTE un-closed delimiter
+//~^ ERROR `main` function not found
+//~^^ NOTE main function must be defined
+//~^^^ NOTE you have one or more functions
   match Some(10) {
   //~^ NOTE this delimiter might not be properly closed...
       Some(y) => { panic!(); }
@@ -11,5 +14,5 @@ fn bar() {
     while (i < 1000) {}
 }
 
-fn main() {} //~ NOTE here is a function named 'main'
+fn main() {} //~ NOTE here is a function named `main`
              //~ ERROR this file contains an un-closed delimiter
diff --git a/src/test/ui/parser/issue-2354.stderr b/src/test/ui/parser/issue-2354.stderr
index 7098da738b8..038e3dcfa40 100644
--- a/src/test/ui/parser/issue-2354.stderr
+++ b/src/test/ui/parser/issue-2354.stderr
@@ -1,8 +1,9 @@
 error: this file contains an un-closed delimiter
-  --> $DIR/issue-2354.rs:15:66
+  --> $DIR/issue-2354.rs:18:66
    |
 LL | fn foo() {
    |          - un-closed delimiter
+...
 LL |   match Some(10) {
    |                  - this delimiter might not be properly closed...
 ...
@@ -13,13 +14,24 @@ LL |
    |                                                                  ^
 
 error[E0601]: `main` function not found in crate `issue_2354`
+  --> $DIR/issue-2354.rs:1:1
+   |
+LL | / fn foo() {
+LL | |
+LL | |
+LL | |
+...  |
+LL | | fn main() {}
+LL | |
+   | |_________________________________________________________________^ the main function must be defined at the crate level (in `$DIR/issue-2354.rs`)
    |
-   = 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'
-  --> $DIR/issue-2354.rs:14:1
+note: here is a function named `main`
+  --> $DIR/issue-2354.rs:17:1
    |
 LL | fn main() {}
    | ^^^^^^^^^^^^
+   = note: you have one or more functions named `main` not defined at the crate level
+   = help: either move the `main` function definitions or attach the `#[main]` attribute to one of them
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/parser/lex-bad-char-literals-2.rs b/src/test/ui/parser/lex-bad-char-literals-2.rs
index 1e180f87fc1..d35dafd9a34 100644
--- a/src/test/ui/parser/lex-bad-char-literals-2.rs
+++ b/src/test/ui/parser/lex-bad-char-literals-2.rs
@@ -2,3 +2,5 @@
 static c: char =
     'nope' //~ ERROR: character literal may only contain one codepoint
 ;
+
+fn main() {}
diff --git a/src/test/ui/parser/lex-bad-char-literals-2.stderr b/src/test/ui/parser/lex-bad-char-literals-2.stderr
index b0a4ed02434..5653d4ea672 100644
--- a/src/test/ui/parser/lex-bad-char-literals-2.stderr
+++ b/src/test/ui/parser/lex-bad-char-literals-2.stderr
@@ -8,10 +8,5 @@ help: if you meant to write a `str` literal, use double quotes
 LL |     "nope"
    |     ^^^^^^
 
-error[E0601]: `main` function not found in crate `lex_bad_char_literals_2`
-   |
-   = note: consider adding a `main` function to `$DIR/lex-bad-char-literals-2.rs`
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0601`.
diff --git a/src/test/ui/parser/unclosed-delimiter-in-dep.stderr b/src/test/ui/parser/unclosed-delimiter-in-dep.stderr
index 633c63bea91..818f61b4d22 100644
--- a/src/test/ui/parser/unclosed-delimiter-in-dep.stderr
+++ b/src/test/ui/parser/unclosed-delimiter-in-dep.stderr
@@ -1,5 +1,5 @@
 error: incorrect close delimiter: `}`
-  --> $DIR/unclosed_delim_mod.rs:5:1
+  --> $DIR/unclosed_delim_mod.rs:7:1
    |
 LL | pub fn new() -> Result<Value, ()> {
    |                                   - close delimiter possibly meant for this
diff --git a/src/test/ui/parser/unclosed_delim_mod.rs b/src/test/ui/parser/unclosed_delim_mod.rs
index b1664f49dc5..486e2331281 100644
--- a/src/test/ui/parser/unclosed_delim_mod.rs
+++ b/src/test/ui/parser/unclosed_delim_mod.rs
@@ -1,3 +1,5 @@
+fn main() {}
+
 pub struct Value {}
 pub fn new() -> Result<Value, ()> {
     Ok(Value {
diff --git a/src/test/ui/parser/unclosed_delim_mod.stderr b/src/test/ui/parser/unclosed_delim_mod.stderr
index cc04eb531cb..fe2d968af0f 100644
--- a/src/test/ui/parser/unclosed_delim_mod.stderr
+++ b/src/test/ui/parser/unclosed_delim_mod.stderr
@@ -1,5 +1,5 @@
 error: incorrect close delimiter: `}`
-  --> $DIR/unclosed_delim_mod.rs:5:1
+  --> $DIR/unclosed_delim_mod.rs:7:1
    |
 LL | pub fn new() -> Result<Value, ()> {
    |                                   - close delimiter possibly meant for this
@@ -9,10 +9,5 @@ LL |     }
 LL | }
    | ^ incorrect close delimiter
 
-error[E0601]: `main` function not found in crate `unclosed_delim_mod`
-   |
-   = note: consider adding a `main` function to `$DIR/unclosed_delim_mod.rs`
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0601`.