From 52acaa69743be657f7d3003ca2a2abf7f1cd7a2e Mon Sep 17 00:00:00 2001
From: Mazdak Farrokhzad <twingoow@gmail.com>
Date: Tue, 3 Dec 2019 10:19:58 +0100
Subject: implement recovery in check_assoc_op

---
 src/librustc_parse/parser/diagnostics.rs | 18 +-----------------
 src/librustc_parse/parser/expr.rs        | 26 +++++++++++++++++++++++++-
 src/librustc_parse/parser/stmt.rs        | 22 ++--------------------
 3 files changed, 28 insertions(+), 38 deletions(-)

(limited to 'src/librustc_parse/parser')

diff --git a/src/librustc_parse/parser/diagnostics.rs b/src/librustc_parse/parser/diagnostics.rs
index ba125cacab4..8b58fb03bf4 100644
--- a/src/librustc_parse/parser/diagnostics.rs
+++ b/src/librustc_parse/parser/diagnostics.rs
@@ -11,7 +11,7 @@ use syntax::ptr::P;
 use syntax::ThinVec;
 use syntax::util::parser::AssocOp;
 use syntax::struct_span_err;
-use syntax_pos::symbol::{kw, sym};
+use syntax_pos::symbol::kw;
 use syntax_pos::{Span, DUMMY_SP, MultiSpan, SpanSnippetError};
 
 use log::{debug, trace};
@@ -312,22 +312,6 @@ impl<'a> Parser<'a> {
         };
         self.last_unexpected_token_span = Some(self.token.span);
         let mut err = self.fatal(&msg_exp);
-        if self.token.is_ident_named(sym::and) {
-            err.span_suggestion_short(
-                self.token.span,
-                "use `&&` instead of `and` for the boolean operator",
-                "&&".to_string(),
-                Applicability::MaybeIncorrect,
-            );
-        }
-        if self.token.is_ident_named(sym::or) {
-            err.span_suggestion_short(
-                self.token.span,
-                "use `||` instead of `or` for the boolean operator",
-                "||".to_string(),
-                Applicability::MaybeIncorrect,
-            );
-        }
         let sp = if self.token == token::Eof {
             // This is EOF; don't want to point at the following char, but rather the last token.
             self.prev_span
diff --git a/src/librustc_parse/parser/expr.rs b/src/librustc_parse/parser/expr.rs
index f20d0aa2236..0792f1b3b7f 100644
--- a/src/librustc_parse/parser/expr.rs
+++ b/src/librustc_parse/parser/expr.rs
@@ -345,7 +345,31 @@ impl<'a> Parser<'a> {
     ///
     /// Also performs recovery for `and` / `or` which are mistaken for `&&` and `||` respectively.
     fn check_assoc_op(&self) -> Option<AssocOp> {
-        AssocOp::from_token(&self.token)
+        match (AssocOp::from_token(&self.token), &self.token.kind) {
+            (op @ Some(_), _) => op,
+            (None, token::Ident(sym::and, false)) => {
+                self.error_bad_logical_op("and", "&&", "conjunction");
+                Some(AssocOp::LAnd)
+            }
+            (None, token::Ident(sym::or, false)) => {
+                self.error_bad_logical_op("or", "||", "disjunction");
+                Some(AssocOp::LOr)
+            }
+            _ => None,
+        }
+    }
+
+    /// Error on `and` and `or` suggesting `&&` and `||` respectively.
+    fn error_bad_logical_op(&self, bad: &str, good: &str, english: &str) {
+        self.struct_span_err(self.token.span, &format!("`{}` is not a logical operator", bad))
+            .span_suggestion(
+                self.token.span,
+                &format!("instead of `{}`, use `{}` to perform logical {}", bad, good, english),
+                good.to_string(),
+                Applicability::MachineApplicable,
+            )
+            .note("unlike in e.g., python and PHP, `&&` and `||` are used for logical operators")
+            .emit();
     }
 
     /// Checks if this expression is a successfully parsed statement.
diff --git a/src/librustc_parse/parser/stmt.rs b/src/librustc_parse/parser/stmt.rs
index d1ed6968fb9..036badfe75d 100644
--- a/src/librustc_parse/parser/stmt.rs
+++ b/src/librustc_parse/parser/stmt.rs
@@ -15,7 +15,7 @@ use syntax::ast::{Attribute, AttrStyle, VisibilityKind, MacStmtStyle, Mac};
 use syntax::util::classify;
 use syntax::token;
 use syntax_pos::source_map::{respan, Span};
-use syntax_pos::symbol::{kw, sym};
+use syntax_pos::symbol::kw;
 
 use std::mem;
 
@@ -301,25 +301,7 @@ impl<'a> Parser<'a> {
         let sp = self.token.span;
         let tok = self.this_token_descr();
         let mut e = self.span_fatal(sp, &format!("expected `{{`, found {}", tok));
-        let do_not_suggest_help =
-            self.token.is_keyword(kw::In) || self.token == token::Colon;
-
-        if self.token.is_ident_named(sym::and) {
-            e.span_suggestion_short(
-                self.token.span,
-                "use `&&` instead of `and` for the boolean operator",
-                "&&".to_string(),
-                Applicability::MaybeIncorrect,
-            );
-        }
-        if self.token.is_ident_named(sym::or) {
-            e.span_suggestion_short(
-                self.token.span,
-                "use `||` instead of `or` for the boolean operator",
-                "||".to_string(),
-                Applicability::MaybeIncorrect,
-            );
-        }
+        let do_not_suggest_help = self.token.is_keyword(kw::In) || self.token == token::Colon;
 
         // Check to see if the user has written something like
         //
-- 
cgit 1.4.1-3-g733a5