Also support statements and patterns for macro expansion

Author: GuillaumeGomez

src/librustdoc/html/macro_expansion.rs

@@ -1,5 +1,5 @@
-use rustc_ast::visit::{Visitor, walk_crate, walk_expr, walk_item};
-use rustc_ast::{Crate, Expr, Item};
+use rustc_ast::visit::{Visitor, walk_crate, walk_expr, walk_item, walk_pat, walk_stmt};
+use rustc_ast::{Crate, Expr, Item, Pat, Stmt};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_span::source_map::SourceMap;
 use rustc_span::{BytePos, Span};
@@ -137,4 +137,20 @@ impl<'ast> Visitor<'ast> for ExpandedCodeVisitor<'ast> {
             walk_item(self, item);
         }
     }
+
+    fn visit_stmt(&mut self, stmt: &'ast Stmt) {
+        if stmt.span.from_expansion() {
+            self.handle_new_span(stmt.span, || rustc_ast_pretty::pprust::stmt_to_string(stmt));
+        } else {
+            walk_stmt(self, stmt);
+        }
+    }
+
+    fn visit_pat(&mut self, pat: &'ast Pat) {
+        if pat.span.from_expansion() {
+            self.handle_new_span(pat.span, || rustc_ast_pretty::pprust::pat_to_string(pat));
+        } else {
+            walk_pat(self, pat);
+        }
+    }
 }

tests/rustdoc/macro/macro_expansion.rs

@@ -0,0 +1,28 @@
+// This test checks that patterns and statements are also getting expanded.
+
+//@ compile-flags: -Zunstable-options --generate-macro-expansion
+
+#![crate_name = "foo"]
+
+//@ has 'src/foo/macro_expansion.rs.html'
+//@ count - '//span[@class="expansion"]' 2
+
+macro_rules! pat {
+    ($x:literal) => {
+        Some($x)
+    }
+}
+
+macro_rules! stmt {
+    ($x:expr) => {{
+        let _ = $x;
+    }}
+}
+
+fn bar() {
+    match Some("hello") {
+        pat!("blolb") => {}
+        _ => {}
+    }
+    stmt!(1)
+}