defatalize BangProcMacro::expand

src/test/ui/proc-macro/invalid-punct-ident-1.rs

@@ -14,3 +14,5 @@
 extern crate invalid_punct_ident;
 
 invalid_punct!(); //~ ERROR proc macro panicked
+
+fn main() {}

src/test/ui/proc-macro/invalid-punct-ident-2.rs

@@ -14,3 +14,5 @@
 extern crate invalid_punct_ident;
 
 invalid_ident!(); //~ ERROR proc macro panicked
+
+fn main() {}

src/test/ui/proc-macro/invalid-punct-ident-3.rs

@@ -14,3 +14,5 @@
 extern crate invalid_punct_ident;
 
 invalid_raw_ident!(); //~ ERROR proc macro panicked
+
+fn main() {}

src/test/ui/proc-macro/invalid-punct-ident-4.rs

@@ -1,7 +1,10 @@
 // aux-build:invalid-punct-ident.rs
 
-#[macro_use]
+// We use `main` not found below as a witness for error recovery in proc macro expansion.
+
+#[macro_use] //~ ERROR `main` function not found
 extern crate invalid_punct_ident;
 
-lexer_failure!(); //~ ERROR proc macro panicked
-                  //~| ERROR unexpected closing delimiter: `)`
+lexer_failure!();
+//~^ ERROR proc macro panicked
+//~| ERROR unexpected closing delimiter: `)`

src/test/ui/proc-macro/invalid-punct-ident-4.stderr

@@ -1,5 +1,5 @@
 error: unexpected closing delimiter: `)`
-  --> $DIR/invalid-punct-ident-4.rs:6:1
+  --> $DIR/invalid-punct-ident-4.rs:8:1
    |
 LL | lexer_failure!();
    | ^^^^^^^^^^^^^^^^^ unexpected closing delimiter
@@ -7,10 +7,20 @@ LL | lexer_failure!();
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: proc macro panicked
-  --> $DIR/invalid-punct-ident-4.rs:6:1
+  --> $DIR/invalid-punct-ident-4.rs:8:1
    |
 LL | lexer_failure!();
    | ^^^^^^^^^^^^^^^^^
 
-error: aborting due to 2 previous errors
+error[E0601]: `main` function not found in crate `invalid_punct_ident_4`
+  --> $DIR/invalid-punct-ident-4.rs:5:1
+   |
+LL | / #[macro_use]
+LL | | extern crate invalid_punct_ident;
+LL | |
+LL | | lexer_failure!();
+   | |_________________^ consider adding a `main` function to `$DIR/invalid-punct-ident-4.rs`
 
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0601`.