From cef7764a7624fabeb151b861f005a9d89da91a09 Mon Sep 17 00:00:00 2001
From: Yuki Okushi <huyuumi.dev@gmail.com>
Date: Wed, 29 Jan 2020 18:02:58 +0900
Subject: [PATCH 1/2] Avoid ICE in macro's diagnostics

---
 src/librustc_parse/parser/item.rs             |  40 ++++++++++--------
 src/test/ui/parser/issue-62524.stderr         |   5 +--
 src/test/ui/parser/issue-68629.rs             | Bin 0 -> 336 bytes
 src/test/ui/parser/issue-68629.stderr         | Bin 0 -> 1441 bytes
 .../ui/parser/mbe_missing_right_paren.stderr  |   4 +-
 5 files changed, 27 insertions(+), 22 deletions(-)
 create mode 100644 src/test/ui/parser/issue-68629.rs
 create mode 100644 src/test/ui/parser/issue-68629.stderr

diff --git a/src/librustc_parse/parser/item.rs b/src/librustc_parse/parser/item.rs
index 31db7fc5f759d..11adc9fafd6a8 100644
--- a/src/librustc_parse/parser/item.rs
+++ b/src/librustc_parse/parser/item.rs
@@ -1638,26 +1638,32 @@ impl<'a> Parser<'a> {
             .span_to_snippet(self.prev_span)
             .map(|s| s.ends_with(")") || s.ends_with("]"))
             .unwrap_or(false);
-        let right_brace_span = if has_close_delim {
-            // it's safe to peel off one character only when it has the close delim
-            self.prev_span.with_lo(self.prev_span.hi() - BytePos(1))
-        } else {
-            self.prev_span.shrink_to_hi()
-        };
 
-        self.struct_span_err(
+        let mut err = self.struct_span_err(
             self.prev_span,
             "macros that expand to items must be delimited with braces or followed by a semicolon",
-        )
-        .multipart_suggestion(
-            "change the delimiters to curly braces",
-            vec![
-                (self.prev_span.with_hi(self.prev_span.lo() + BytePos(1)), "{".to_string()),
-                (right_brace_span, '}'.to_string()),
-            ],
-            Applicability::MaybeIncorrect,
-        )
-        .span_suggestion(
+        );
+
+        // To avoid ICE, we shouldn't emit actual suggestions when it hasn't closing delims
+        if has_close_delim {
+            err.multipart_suggestion(
+                "change the delimiters to curly braces",
+                vec![
+                    (self.prev_span.with_hi(self.prev_span.lo() + BytePos(1)), '{'.to_string()),
+                    (self.prev_span.with_lo(self.prev_span.hi() - BytePos(1)), '}'.to_string()),
+                ],
+                Applicability::MaybeIncorrect,
+            );
+        } else {
+            err.span_suggestion(
+                self.prev_span,
+                "change the delimiters to curly braces",
+                " { /* items */ }".to_string(),
+                Applicability::MaybeIncorrect,
+            );
+        }
+
+        err.span_suggestion(
             self.prev_span.shrink_to_hi(),
             "add a semicolon",
             ';'.to_string(),
diff --git a/src/test/ui/parser/issue-62524.stderr b/src/test/ui/parser/issue-62524.stderr
index 3482435cd1d03..8191c9682cefd 100644
--- a/src/test/ui/parser/issue-62524.stderr
+++ b/src/test/ui/parser/issue-62524.stderr
@@ -16,9 +16,8 @@ LL | | Ϥ,
    |
 help: change the delimiters to curly braces
    |
-LL | y!{
-LL | Ϥ}
-   |
+LL | y! { /* items */ }
+   |    ^^^^^^^^^^^^^^^
 help: add a semicolon
    |
 LL | Ϥ,;
diff --git a/src/test/ui/parser/issue-68629.rs b/src/test/ui/parser/issue-68629.rs
new file mode 100644
index 0000000000000000000000000000000000000000..672a31f12c838bf7b2e54e6012354acea5852515
GIT binary patch
literal 336
zcmZvXJx;_x424tY3`jf<5T&Q!A~frragxy{c4RwRRveA9a2G5JXwult``*tuqRpbl
zL$vxB!l<oH=0W(LpS>SPu$kJhQv{p5;*gu@UEo0$&<UY8mJ?wt%`vr=QB;DOI7kvN
zt2$RyUfb5v^90?fm^xyi0DtTxHB*q{&9NOGxbh!gPx!Ks%$)qc%+gL#4qG3%8kN&+
rg+w&6bO!!*z$N^GCTW#pyy(t-|MVQ*y}W<6zUzQVVBcR#Z+W*L$M$$^

literal 0
HcmV?d00001

diff --git a/src/test/ui/parser/issue-68629.stderr b/src/test/ui/parser/issue-68629.stderr
new file mode 100644
index 0000000000000000000000000000000000000000..a7885ecec5647e4c3eece95ce5b4ea25c70273ca
GIT binary patch
literal 1441
zcmds1!A{#i5Y5@&P^qs{Pe^GBsA=L#oO-FmsaH^7vtHvB_D;03Zi*7VjBnvz7~2pB
zh#gRGox{qqy>I5tdo#v+@-a$x?P%%1LHPhm5$M{u80Y2cP~S$taCm~xKY#rmS?1CV
z$CL5V^o!?s5+BM}tfSLYtnuMv;K8S}m95`l7DZ-1e%g<J^pE&o`{BQJ!{coPdJ{~a
z^=B{uQU`y3N9sh*;vIe3lV-b3d((u>GE$oxXmUYW$52j8pmSoAAThZuY%pHR>k?jw
zjr&?B7k2}SO=`nbNA<KLYwe{D64jMWv<CbC7!^u;VuVZun7<3<5*bQ}Dg~n`Ibd!!
zLM2$*kYVnXHVpDeDbHysQqFInz^1U8a&kR-PU7!da^mGE<3eKAO!*oe+N`UeHZg1P
zGLtW2=uEjQBW&8Dy^tg5(&smim2VZ$Y!a+6I(X!KFhVuSjcG7@9#NA;CCLlAPn+pg
z#XnlC9d^>nISMi&()C&hTn4^`b;3YKhczvX0CWw<BtCw{rQM3HYt@{5u<i;;DZL>~
PvGC@PrIJxEPL84np&G4n

literal 0
HcmV?d00001

diff --git a/src/test/ui/parser/mbe_missing_right_paren.stderr b/src/test/ui/parser/mbe_missing_right_paren.stderr
index c5b3cc275ce9a..4ce39de886649 100644
--- a/src/test/ui/parser/mbe_missing_right_paren.stderr
+++ b/src/test/ui/parser/mbe_missing_right_paren.stderr
@@ -14,8 +14,8 @@ LL | macro_rules! abc(ؼ
    |
 help: change the delimiters to curly braces
    |
-LL | macro_rules! abc{ؼ}
-   |                 ^ ^
+LL | macro_rules! abc { /* items */ }
+   |                  ^^^^^^^^^^^^^^^
 help: add a semicolon
    |
 LL | macro_rules! abc(ؼ;

From b1c91ee1b1a671e1d277763169abd9986195712a Mon Sep 17 00:00:00 2001
From: Yuki Okushi <huyuumi.dev@gmail.com>
Date: Thu, 30 Jan 2020 17:33:19 +0900
Subject: [PATCH 2/2] Change Applicability to `HasPlaceholders`

---
 src/librustc_parse/parser/item.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/librustc_parse/parser/item.rs b/src/librustc_parse/parser/item.rs
index 11adc9fafd6a8..b55756d8129de 100644
--- a/src/librustc_parse/parser/item.rs
+++ b/src/librustc_parse/parser/item.rs
@@ -1659,7 +1659,7 @@ impl<'a> Parser<'a> {
                 self.prev_span,
                 "change the delimiters to curly braces",
                 " { /* items */ }".to_string(),
-                Applicability::MaybeIncorrect,
+                Applicability::HasPlaceholders,
             );
         }