From 4bd09ce06f50d266c992c984cc993384d5e6655e Mon Sep 17 00:00:00 2001
From: Owen Avery <powerboat9.gamer@gmail.com>
Date: Tue, 14 Feb 2023 18:42:39 -0500
Subject: [PATCH] gccrs: Parse AltPattern

Renamed Parser::parse_pattern to Parser::parse_pattern_no_alt and created
new method Parser::parse_pattern to handle alternate patterns.

gcc/rust/ChangeLog:

	* parse/rust-parse-impl.h
	(Parser::parse_pattern): Add.
	(Parser::parse_pattern_no_alt): Rename.
	* parse/rust-parse.h:
	(Parser::parse_pattern): Add.
	(Parser::parse_pattern_no_alt): Rename.

gcc/testsuite/ChangeLog:

	* rust/compile/pattern-or.rs: New test.

Signed-off-by: Owen Avery <powerboat9.gamer@gmail.com>
---
 gcc/rust/parse/rust-parse-impl.h         | 33 +++++++++++++++++++++++-
 gcc/rust/parse/rust-parse.h              |  1 +
 gcc/testsuite/rust/compile/pattern-or.rs |  7 +++++
 3 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/rust/compile/pattern-or.rs

diff --git a/gcc/rust/parse/rust-parse-impl.h b/gcc/rust/parse/rust-parse-impl.h
index ef0eaef1b367..d1f192e3183e 100644
--- a/gcc/rust/parse/rust-parse-impl.h
+++ b/gcc/rust/parse/rust-parse-impl.h
@@ -10619,10 +10619,41 @@ Parser<ManagedTokenSource>::parse_range_pattern_bound ()
     }
 }
 
-// Parses a pattern (will further disambiguate any pattern).
 template <typename ManagedTokenSource>
 std::unique_ptr<AST::Pattern>
 Parser<ManagedTokenSource>::parse_pattern ()
+{
+  Location start_locus = lexer.peek_token ()->get_locus ();
+
+  /* skip optional starting pipe */
+  maybe_skip_token (PIPE);
+
+  auto first = parse_pattern_no_alt ();
+
+  if (lexer.peek_token ()->get_id () != PIPE)
+    /* no alternates */
+    return first;
+
+  std::vector<std::unique_ptr<AST::Pattern>> alts;
+  alts.push_back (std::move (first));
+
+  do
+    {
+      lexer.skip_token ();
+      alts.push_back (parse_pattern_no_alt ());
+    }
+  while (lexer.peek_token ()->get_id () == PIPE);
+
+  /* alternates */
+  return std::unique_ptr<AST::Pattern> (
+    new AST::AltPattern (std::move (alts), start_locus));
+}
+
+// Parses a pattern without alternates ('|')
+// (will further disambiguate any pattern).
+template <typename ManagedTokenSource>
+std::unique_ptr<AST::Pattern>
+Parser<ManagedTokenSource>::parse_pattern_no_alt ()
 {
   const_TokenPtr t = lexer.peek_token ();
   switch (t->get_id ())
diff --git a/gcc/rust/parse/rust-parse.h b/gcc/rust/parse/rust-parse.h
index a4b65c502217..54a87c946f99 100644
--- a/gcc/rust/parse/rust-parse.h
+++ b/gcc/rust/parse/rust-parse.h
@@ -126,6 +126,7 @@ public:
 
   std::unique_ptr<AST::Item> parse_item (bool called_from_statement);
   std::unique_ptr<AST::Pattern> parse_pattern ();
+  std::unique_ptr<AST::Pattern> parse_pattern_no_alt ();
 
   /**
    * Parse a statement
diff --git a/gcc/testsuite/rust/compile/pattern-or.rs b/gcc/testsuite/rust/compile/pattern-or.rs
new file mode 100644
index 000000000000..054b43f05046
--- /dev/null
+++ b/gcc/testsuite/rust/compile/pattern-or.rs
@@ -0,0 +1,7 @@
+// { dg-additional-options "-fsyntax-only" }
+
+fn main() {
+    match ((12, 13)) {
+        (_, 5) | (12, _) => {}
+    }
+}
-- 
2.47.2