3 files changed, 82 insertions, 12 deletions

diff --git a/crates/ra_parser/src/grammar/expressions.rs b/crates/ra_parser/src/grammar/expressions.rs
index e35c46a5e..c8ce07179 100644
--- a/crates/ra_parser/src/grammar/expressions.rs
+++ b/crates/ra_parser/src/grammar/expressions.rs
@@ -38,6 +38,13 @@ pub(crate) fn block(p: &mut Parser) {
     m.complete(p, BLOCK);
 }
 
+fn is_expr_stmt_attr_allowed(kind: SyntaxKind) -> bool {
+    match kind {
+        BIN_EXPR | RANGE_EXPR | IF_EXPR => false,
+        _ => true,
+    }
+}
+
 pub(crate) fn expr_block_contents(p: &mut Parser) {
     // This is checked by a validator
     attributes::inner_attributes(p);
@@ -62,6 +69,7 @@ pub(crate) fn expr_block_contents(p: &mut Parser) {
         //     #[C] #[D] {}
         //     #[D] return ();
         // }
+        let has_attrs = p.at(POUND);
         attributes::outer_attributes(p);
         if p.at(LET_KW) {
             let_stmt(p, m);
@@ -74,18 +82,17 @@ pub(crate) fn expr_block_contents(p: &mut Parser) {
         };
 
         let (cm, blocklike) = expr_stmt(p);
-        let cm = match cm {
-            None => {
-                if p.at(R_CURLY) {
-                    m.abandon(p);
-                } else {
-                    p.expect(SEMI);
-                    m.complete(p, EXPR_STMT);
-                }
-                continue;
+
+        if let Some(cm) = &cm {
+            if has_attrs && !is_expr_stmt_attr_allowed(cm.kind()) {
+                // test_err attr_on_expr_not_allowed
+                // fn foo() {
+                //    #[A] 1 + 2;
+                //    #[B] if true {};
+                // }
+                p.error(format!("attributes are not allowed on {:?}", cm.kind()));
             }
-            Some(cm) => cm,
-        };
+        }
 
         if p.at(R_CURLY) {
             // test attr_on_last_expr_in_block
@@ -93,7 +100,11 @@ pub(crate) fn expr_block_contents(p: &mut Parser) {
             //     { #[A] bar!()? }
             //     #[B] &()
             // }
-            m.contract_child(p, cm);
+            if let Some(cm) = cm {
+                m.contract_child(p, cm);
+            } else {
+                m.abandon(p);
+            }
         } else {
             // test no_semi_after_block
             // fn foo() {
diff --git a/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.rs b/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.rs
new file mode 100644
index 000000000..d725a07ce
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.rs
@@ -0,0 +1,4 @@
+fn foo() {
+   #[A] 1 + 2;
+   #[B] if true {};
+}
diff --git a/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.txt b/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.txt
new file mode 100644
index 000000000..fdea1ec1e
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.txt
@@ -0,0 +1,55 @@
+SOURCE_FILE@[0; 48)
+  FN_DEF@[0; 47)
+    FN_KW@[0; 2)
+    WHITESPACE@[2; 3)
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7)
+      R_PAREN@[7; 8)
+    WHITESPACE@[8; 9)
+    BLOCK@[9; 47)
+      L_CURLY@[9; 10)
+      WHITESPACE@[10; 14)
+      EXPR_STMT@[14; 25)
+        ATTR@[14; 18)
+          POUND@[14; 15)
+          TOKEN_TREE@[15; 18)
+            L_BRACK@[15; 16)
+            IDENT@[16; 17) "A"
+            R_BRACK@[17; 18)
+        WHITESPACE@[18; 19)
+        BIN_EXPR@[19; 24)
+          LITERAL@[19; 20)
+            INT_NUMBER@[19; 20) "1"
+          WHITESPACE@[20; 21)
+          PLUS@[21; 22)
+          WHITESPACE@[22; 23)
+          LITERAL@[23; 24)
+            INT_NUMBER@[23; 24) "2"
+            err: `attributes are not allowed on BIN_EXPR`
+        SEMI@[24; 25)
+      WHITESPACE@[25; 29)
+      EXPR_STMT@[29; 45)
+        ATTR@[29; 33)
+          POUND@[29; 30)
+          TOKEN_TREE@[30; 33)
+            L_BRACK@[30; 31)
+            IDENT@[31; 32) "B"
+            R_BRACK@[32; 33)
+        WHITESPACE@[33; 34)
+        IF_EXPR@[34; 44)
+          IF_KW@[34; 36)
+          WHITESPACE@[36; 37)
+          CONDITION@[37; 41)
+            LITERAL@[37; 41)
+              TRUE_KW@[37; 41)
+          WHITESPACE@[41; 42)
+          BLOCK@[42; 44)
+            L_CURLY@[42; 43)
+            R_CURLY@[43; 44)
+            err: `attributes are not allowed on IF_EXPR`
+        SEMI@[44; 45)
+      WHITESPACE@[45; 46)
+      R_CURLY@[46; 47)
+  WHITESPACE@[47; 48)