mbe: Parse macro attribute rules

This handles various kinds of errors, but does not allow applying the
attributes yet.

This adds the feature gate `macro_attr`.

2 files changed, 112 insertions, 0 deletions

diff --git a/tests/ui/parser/macro/macro-attr-bad.rs b/tests/ui/parser/macro/macro-attr-bad.rs
new file mode 100644
index 00000000000..4313a4d04ab
--- /dev/null
+++ b/tests/ui/parser/macro/macro-attr-bad.rs
@@ -0,0 +1,32 @@
+#![crate_type = "lib"]
+#![feature(macro_attr)]
+
+macro_rules! attr_incomplete_1 { attr }
+//~^ ERROR macro definition ended unexpectedly
+
+macro_rules! attr_incomplete_2 { attr() }
+//~^ ERROR macro definition ended unexpectedly
+
+macro_rules! attr_incomplete_3 { attr() {} }
+//~^ ERROR expected `=>`
+
+macro_rules! attr_incomplete_4 { attr() {} => }
+//~^ ERROR macro definition ended unexpectedly
+
+macro_rules! attr_noparens_1 { attr{} {} => {} }
+//~^ ERROR macro attribute argument matchers require parentheses
+
+macro_rules! attr_noparens_2 { attr[] {} => {} }
+//~^ ERROR macro attribute argument matchers require parentheses
+
+macro_rules! attr_noparens_3 { attr _ {} => {} }
+//~^ ERROR invalid macro matcher
+
+macro_rules! attr_dup_matcher_1 { attr() {$x:ident $x:ident} => {} }
+//~^ ERROR duplicate matcher binding
+
+macro_rules! attr_dup_matcher_2 { attr($x:ident $x:ident) {} => {} }
+//~^ ERROR duplicate matcher binding
+
+macro_rules! attr_dup_matcher_3 { attr($x:ident) {$x:ident} => {} }
+//~^ ERROR duplicate matcher binding
diff --git a/tests/ui/parser/macro/macro-attr-bad.stderr b/tests/ui/parser/macro/macro-attr-bad.stderr
new file mode 100644
index 00000000000..4d286b66649
--- /dev/null
+++ b/tests/ui/parser/macro/macro-attr-bad.stderr
@@ -0,0 +1,80 @@
+error: macro definition ended unexpectedly
+  --> $DIR/macro-attr-bad.rs:4:38
+   |
+LL | macro_rules! attr_incomplete_1 { attr }
+   |                                      ^ expected macro attr args
+
+error: macro definition ended unexpectedly
+  --> $DIR/macro-attr-bad.rs:7:40
+   |
+LL | macro_rules! attr_incomplete_2 { attr() }
+   |                                        ^ expected macro attr body
+
+error: expected `=>`, found end of macro arguments
+  --> $DIR/macro-attr-bad.rs:10:43
+   |
+LL | macro_rules! attr_incomplete_3 { attr() {} }
+   |                                           ^ expected `=>`
+
+error: macro definition ended unexpectedly
+  --> $DIR/macro-attr-bad.rs:13:46
+   |
+LL | macro_rules! attr_incomplete_4 { attr() {} => }
+   |                                              ^ expected right-hand side of macro rule
+
+error: macro attribute argument matchers require parentheses
+  --> $DIR/macro-attr-bad.rs:16:36
+   |
+LL | macro_rules! attr_noparens_1 { attr{} {} => {} }
+   |                                    ^^
+   |
+help: the delimiters should be `(` and `)`
+   |
+LL - macro_rules! attr_noparens_1 { attr{} {} => {} }
+LL + macro_rules! attr_noparens_1 { attr() {} => {} }
+   |
+
+error: macro attribute argument matchers require parentheses
+  --> $DIR/macro-attr-bad.rs:19:36
+   |
+LL | macro_rules! attr_noparens_2 { attr[] {} => {} }
+   |                                    ^^
+   |
+help: the delimiters should be `(` and `)`
+   |
+LL - macro_rules! attr_noparens_2 { attr[] {} => {} }
+LL + macro_rules! attr_noparens_2 { attr() {} => {} }
+   |
+
+error: invalid macro matcher; matchers must be contained in balanced delimiters
+  --> $DIR/macro-attr-bad.rs:22:37
+   |
+LL | macro_rules! attr_noparens_3 { attr _ {} => {} }
+   |                                     ^
+
+error: duplicate matcher binding
+  --> $DIR/macro-attr-bad.rs:25:52
+   |
+LL | macro_rules! attr_dup_matcher_1 { attr() {$x:ident $x:ident} => {} }
+   |                                           -------- ^^^^^^^^ duplicate binding
+   |                                           |
+   |                                           previous binding
+
+error: duplicate matcher binding
+  --> $DIR/macro-attr-bad.rs:28:49
+   |
+LL | macro_rules! attr_dup_matcher_2 { attr($x:ident $x:ident) {} => {} }
+   |                                        -------- ^^^^^^^^ duplicate binding
+   |                                        |
+   |                                        previous binding
+
+error: duplicate matcher binding
+  --> $DIR/macro-attr-bad.rs:31:51
+   |
+LL | macro_rules! attr_dup_matcher_3 { attr($x:ident) {$x:ident} => {} }
+   |                                        --------   ^^^^^^^^ duplicate binding
+   |                                        |
+   |                                        previous binding
+
+error: aborting due to 10 previous errors
+