[EXPERIMENT] Panic when the pretty-print/reparse check fails

Aaron1011 · Aaron1011 · commit 2e29575463cc · 2020-12-12T22:40:18.000-05:00
Opening for a Crater run. Most of the failures will probably be due to
minor pretty-printer inconsistencies, but we might find some token
collection bugs.
diff --git a/compiler/rustc_parse/src/lib.rs b/compiler/rustc_parse/src/lib.rs
@@ -378,8 +378,10 @@ pub fn nt_to_tokenstream(nt: &Nonterminal, sess: &ParseSess, span: Span) -> Toke
 
         info!("cached   tokens debug: {:?}", tokens);
         info!("reparsed tokens debug: {:?}", reparsed_tokens_with_parens);
+        panic!("Mismatched tokens at {:?} : tokens: {:?}", span, tokens);
+    } else {
+        panic!("Missing tokens at {:?} : reparsed tokens: {:?}", span, reparsed_tokens);
     }
-    reparsed_tokens
 }
 
 // See comments in `Nonterminal::to_tokenstream` for why we care about

Original file line number	Diff line number	Diff line change
`@@ -378,8 +378,10 @@ pub fn nt_to_tokenstream(nt: &Nonterminal, sess: &ParseSess, span: Span) -> Toke`
`378`	`378`
`379`	`379`	`info!("cached tokens debug: {:?}", tokens);`
`380`	`380`	`info!("reparsed tokens debug: {:?}", reparsed_tokens_with_parens);`
	`381`	`+ panic!("Mismatched tokens at {:?} : tokens: {:?}", span, tokens);`
	`382`	`+ } else {`
	`383`	`+ panic!("Missing tokens at {:?} : reparsed tokens: {:?}", span, reparsed_tokens);`
`381`	`384`	`}`
`382`		`- reparsed_tokens`
`383`	`385`	`}`
`384`	`386`
`385`	`387`	// See comments in `Nonterminal::to_tokenstream` for why we care about