Merge #3836

3836: Macro patterns are not confused with expressions. r=matklad a=matklad

We treat macro calls as expressions (there's appropriate Into impl),
which causes problem if there's expresison and non-expression macro in
the same node (like in the match arm).

We fix this problem by nesting macor patterns into another node (the
same way we nest path into PathExpr or PathPat). Ideally, we probably
should add a similar nesting for macro expressions, but that needs
some careful thinking about macros in blocks: `{ am_i_expression!() }`.



bors r+
🤖

Co-authored-by: Aleksey Kladov <[email protected]>

2 files changed, 52 insertions, 11 deletions

diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index 7204ca5b1..0c339b987 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -2563,6 +2563,38 @@ impl LiteralPat {
     }
 }
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct MacroPat {
+    pub(crate) syntax: SyntaxNode,
+}
+impl std::fmt::Display for MacroPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
+impl AstNode for MacroPat {
+    fn can_cast(kind: SyntaxKind) -> bool {
+        match kind {
+            MACRO_PAT => true,
+            _ => false,
+        }
+    }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        if Self::can_cast(syntax.kind()) {
+            Some(Self { syntax })
+        } else {
+            None
+        }
+    }
+    fn syntax(&self) -> &SyntaxNode {
+        &self.syntax
+    }
+}
+impl MacroPat {
+    pub fn macro_call(&self) -> Option<MacroCall> {
+        AstChildren::new(&self.syntax).next()
+    }
+}
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct RecordPat {
     pub(crate) syntax: SyntaxNode,
 }
@@ -4600,6 +4632,7 @@ pub enum Pat {
     SlicePat(SlicePat),
     RangePat(RangePat),
     LiteralPat(LiteralPat),
+    MacroPat(MacroPat),
 }
 impl From<OrPat> for Pat {
     fn from(node: OrPat) -> Pat {
@@ -4671,6 +4704,11 @@ impl From<LiteralPat> for Pat {
         Pat::LiteralPat(node)
     }
 }
+impl From<MacroPat> for Pat {
+    fn from(node: MacroPat) -> Pat {
+        Pat::MacroPat(node)
+    }
+}
 impl std::fmt::Display for Pat {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
@@ -4681,7 +4719,7 @@ impl AstNode for Pat {
         match kind {
             OR_PAT | PAREN_PAT | REF_PAT | BOX_PAT | BIND_PAT | PLACEHOLDER_PAT | DOT_DOT_PAT
             | PATH_PAT | RECORD_PAT | TUPLE_STRUCT_PAT | TUPLE_PAT | SLICE_PAT | RANGE_PAT
-            | LITERAL_PAT => true,
+            | LITERAL_PAT | MACRO_PAT => true,
             _ => false,
         }
     }
@@ -4701,6 +4739,7 @@ impl AstNode for Pat {
             SLICE_PAT => Pat::SlicePat(SlicePat { syntax }),
             RANGE_PAT => Pat::RangePat(RangePat { syntax }),
             LITERAL_PAT => Pat::LiteralPat(LiteralPat { syntax }),
+            MACRO_PAT => Pat::MacroPat(MacroPat { syntax }),
             _ => return None,
         };
         Some(res)
@@ -4721,6 +4760,7 @@ impl AstNode for Pat {
             Pat::SlicePat(it) => &it.syntax,
             Pat::RangePat(it) => &it.syntax,
             Pat::LiteralPat(it) => &it.syntax,
+            Pat::MacroPat(it) => &it.syntax,
         }
     }
 }
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0129_marco_pat.txt b/crates/ra_syntax/test_data/parser/inline/ok/0129_marco_pat.txt
index b05ccc0ed..36d8f4a5f 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0129_marco_pat.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0129_marco_pat.txt
@@ -15,16 +15,17 @@ SOURCE_FILE@[0; 33)
         LET_STMT@[16; 30)
           LET_KW@[16; 19) "let"
           WHITESPACE@[19; 20) " "
-          MACRO_CALL@[20; 25)
-            PATH@[20; 21)
-              PATH_SEGMENT@[20; 21)
-                NAME_REF@[20; 21)
-                  IDENT@[20; 21) "m"
-            EXCL@[21; 22) "!"
-            TOKEN_TREE@[22; 25)
-              L_PAREN@[22; 23) "("
-              IDENT@[23; 24) "x"
-              R_PAREN@[24; 25) ")"
+          MACRO_PAT@[20; 25)
+            MACRO_CALL@[20; 25)
+              PATH@[20; 21)
+                PATH_SEGMENT@[20; 21)
+                  NAME_REF@[20; 21)
+                    IDENT@[20; 21) "m"
+              EXCL@[21; 22) "!"
+              TOKEN_TREE@[22; 25)
+                L_PAREN@[22; 23) "("
+                IDENT@[23; 24) "x"
+                R_PAREN@[24; 25) ")"
           WHITESPACE@[25; 26) " "
           EQ@[26; 27) "="
           WHITESPACE@[27; 28) " "