[gcc/devel/rust/master] Parse AltPattern

[Thomas Schwinge <tschwinge@gcc.gnu.org>]

https://gcc.gnu.org/g:15ca76ea868ccb9dbb0bd1a77f9b13746220499f

commit 15ca76ea868ccb9dbb0bd1a77f9b13746220499f
Author: Owen Avery <powerboat9.gamer@gmail.com>
Date:   Tue Feb 14 18:42:39 2023 -0500

    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>

Diff:
---
 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(-)

diff --git a/gcc/rust/parse/rust-parse-impl.h b/gcc/rust/parse/rust-parse-impl.h
index db32803ddbe..4c39284749d 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 a4b65c50221..54a87c946f9 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 00000000000..054b43f0504
--- /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, _) => {}
+    }
+}