gccrs: ast: Add RestPattern AST node

Add the RestPattern AST node representing ".." code in some rust
context. This commit also provides the different visitors for this node.

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Add visitor.
	* ast/rust-ast-dump.h: Add visitor prototype.
	* ast/rust-ast-full-decls.h (class RestPattern): Add forward
	declaration for class RestPattern.
	* ast/rust-ast-visitor.h: Add visitor prototype.
	* ast/rust-ast.cc (RestPattern::accept_vis): Add function to
	accept a foreign visitor.
	* ast/rust-pattern.h (class RestPattern): Add class RestPattern.
	* checks/errors/rust-feature-gate.h: Add visitor prototype.
	* expand/rust-attribute-visitor.cc (AttrVisitor::visit): Add
	visitor implementation.
	* expand/rust-attribute-visitor.h: Add visitor prototype.
	* hir/rust-ast-lower-base.cc (ASTLoweringBase::visit): Add
	visitor implementation.
	* hir/rust-ast-lower-base.h: Add visitor prototype.
	* resolve/rust-ast-resolve-base.cc (ResolverBase::visit): Add
	visitor implementation.
	* resolve/rust-ast-resolve-base.h: Add visitor prototype.
	* resolve/rust-early-name-resolver.cc (EarlyNameResolver::visit):
	Add visitor implementation.
	* resolve/rust-early-name-resolver.h: Add visitor prototype.
	* util/rust-attributes.cc (AttributeChecker::visit): Add visitor
	implementation.
	* util/rust-attributes.h: Add visitor prototype.

Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>

6 files changed, 27 insertions, 0 deletions

diff --git a/gcc/rust/ast/rust-ast-dump.cc b/gcc/rust/ast/rust-ast-dump.cc
index 97056c6..f619108 100644
--- a/gcc/rust/ast/rust-ast-dump.cc
+++ b/gcc/rust/ast/rust-ast-dump.cc
@@ -1610,6 +1610,10 @@ void
 Dump::visit (WildcardPattern &)
 {}
 
+void
+Dump::visit (RestPattern &)
+{}
+
 // void Dump::visit(RangePatternBound& ){}
 
 void
diff --git a/gcc/rust/ast/rust-ast-dump.h b/gcc/rust/ast/rust-ast-dump.h
index a6adab9..50c9e91 100644
--- a/gcc/rust/ast/rust-ast-dump.h
+++ b/gcc/rust/ast/rust-ast-dump.h
@@ -273,6 +273,7 @@ private:
   void visit (LiteralPattern &pattern);
   void visit (IdentifierPattern &pattern);
   void visit (WildcardPattern &pattern);
+  void visit (RestPattern &pattern);
   // void visit(RangePatternBound& bound);
   void visit (RangePatternBoundLiteral &bound);
   void visit (RangePatternBoundPath &bound);
diff --git a/gcc/rust/ast/rust-ast-full-decls.h b/gcc/rust/ast/rust-ast-full-decls.h
index 352c1b9..5a85646 100644
--- a/gcc/rust/ast/rust-ast-full-decls.h
+++ b/gcc/rust/ast/rust-ast-full-decls.h
@@ -228,6 +228,7 @@ class MetaListNameValueStr;
 class LiteralPattern;
 class IdentifierPattern;
 class WildcardPattern;
+class RestPattern;
 class RangePatternBound;
 class RangePatternBoundLiteral;
 class RangePatternBoundPath;
diff --git a/gcc/rust/ast/rust-ast-visitor.h b/gcc/rust/ast/rust-ast-visitor.h
index 776e1e2..6990d61 100644
--- a/gcc/rust/ast/rust-ast-visitor.h
+++ b/gcc/rust/ast/rust-ast-visitor.h
@@ -183,6 +183,7 @@ public:
   virtual void visit (LiteralPattern &pattern) = 0;
   virtual void visit (IdentifierPattern &pattern) = 0;
   virtual void visit (WildcardPattern &pattern) = 0;
+  virtual void visit (RestPattern &pattern) = 0;
   // virtual void visit(RangePatternBound& bound) = 0;
   virtual void visit (RangePatternBoundLiteral &bound) = 0;
   virtual void visit (RangePatternBoundPath &bound) = 0;
diff --git a/gcc/rust/ast/rust-ast.cc b/gcc/rust/ast/rust-ast.cc
index 13d31cf..6572a3e 100644
--- a/gcc/rust/ast/rust-ast.cc
+++ b/gcc/rust/ast/rust-ast.cc
@@ -5575,6 +5575,12 @@ WildcardPattern::accept_vis (ASTVisitor &vis)
 }
 
 void
+RestPattern::accept_vis (ASTVisitor &vis)
+{
+  vis.visit (*this);
+}
+
+void
 RangePatternBoundLiteral::accept_vis (ASTVisitor &vis)
 {
   vis.visit (*this);
diff --git a/gcc/rust/ast/rust-pattern.h b/gcc/rust/ast/rust-pattern.h
index 1fcd818..0f6cf8f 100644
--- a/gcc/rust/ast/rust-pattern.h
+++ b/gcc/rust/ast/rust-pattern.h
@@ -191,6 +191,20 @@ protected:
   }
 };
 
+class RestPattern : public Pattern
+{
+  Location locus;
+
+public:
+  std::string as_string () const override { return ".."; }
+
+  RestPattern (Location locus) : locus (locus) {}
+
+  Location get_locus () const override final { return locus; }
+
+  void accept_vis (ASTVisitor &vis) override;
+};
+
 // Base range pattern bound (lower or upper limit) - abstract
 class RangePatternBound
 {