Merge #866

866: Add support for wildcard patterns within MatchExprs r=philberty a=philberty

GCC CASE_LABEL_EXPR's contain operand 0 and 1, operand 0 is used for the
low value of a case label and operand 1 for a high value. So with this
CASE_LABEL_EXPR is is possible to support a range of values from low->high
if set apropriately, but for the wildcard case this is effectively a
default case which means we set both operand 0 and 1 to NULL_TREE.

Fixes #853


Co-authored-by: Philip Herron <philip.herron@embecosm.com>

2 files changed, 31 insertions, 15 deletions

diff --git a/gcc/rust/hir/rust-ast-lower-pattern.cc b/gcc/rust/hir/rust-ast-lower-pattern.cc
index 156f023..4bf3c51 100644
--- a/gcc/rust/hir/rust-ast-lower-pattern.cc
+++ b/gcc/rust/hir/rust-ast-lower-pattern.cc
@@ -23,6 +23,23 @@ namespace Rust {
 namespace HIR {
 
 void
+ASTLoweringPattern::visit (AST::IdentifierPattern &pattern)
+{
+  auto crate_num = mappings->get_current_crate ();
+  Analysis::NodeMapping mapping (crate_num, pattern.get_node_id (),
+				 mappings->get_next_hir_id (crate_num),
+				 UNKNOWN_LOCAL_DEFID);
+
+  std::unique_ptr<Pattern> to_bind;
+  translated
+    = new HIR::IdentifierPattern (mapping, pattern.get_ident (),
+				  pattern.get_locus (), pattern.get_is_ref (),
+				  pattern.get_is_mut () ? Mutability::Mut
+							: Mutability::Imm,
+				  std::move (to_bind));
+}
+
+void
 ASTLoweringPattern::visit (AST::PathInExpression &pattern)
 {
   translated = ASTLowerPathInExpression::translate (&pattern);
@@ -135,5 +152,16 @@ ASTLoweringPattern::visit (AST::StructPattern &pattern)
   translated = new HIR::StructPattern (mapping, *path, std::move (elems));
 }
 
+void
+ASTLoweringPattern::visit (AST::WildcardPattern &pattern)
+{
+  auto crate_num = mappings->get_current_crate ();
+  Analysis::NodeMapping mapping (crate_num, pattern.get_node_id (),
+				 mappings->get_next_hir_id (crate_num),
+				 UNKNOWN_LOCAL_DEFID);
+
+  translated = new HIR::WildcardPattern (mapping, pattern.get_locus ());
+}
+
 } // namespace HIR
 } // namespace Rust
diff --git a/gcc/rust/hir/rust-ast-lower-pattern.h b/gcc/rust/hir/rust-ast-lower-pattern.h
index bd25b83..60a3ad1 100644
--- a/gcc/rust/hir/rust-ast-lower-pattern.h
+++ b/gcc/rust/hir/rust-ast-lower-pattern.h
@@ -48,21 +48,7 @@ public:
     return resolver.translated;
   }
 
-  void visit (AST::IdentifierPattern &pattern) override
-  {
-    auto crate_num = mappings->get_current_crate ();
-    Analysis::NodeMapping mapping (crate_num, pattern.get_node_id (),
-				   mappings->get_next_hir_id (crate_num),
-				   UNKNOWN_LOCAL_DEFID);
-
-    std::unique_ptr<Pattern> to_bind;
-    translated
-      = new HIR::IdentifierPattern (mapping, pattern.get_ident (),
-				    pattern.get_locus (), pattern.get_is_ref (),
-				    pattern.get_is_mut () ? Mutability::Mut
-							  : Mutability::Imm,
-				    std::move (to_bind));
-  }
+  void visit (AST::IdentifierPattern &pattern) override;
 
   void visit (AST::PathInExpression &pattern) override;
 
@@ -70,6 +56,8 @@ public:
 
   void visit (AST::TupleStructPattern &pattern) override;
 
+  void visit (AST::WildcardPattern &pattern) override;
+
 private:
   ASTLoweringPattern () : translated (nullptr) {}