Merge #1244

1244: Allow match on integer and char types r=dafaust a=dafaust

Enable compiling match expressions on other primitive types like `i32`, `usize` and `char`.


Co-authored-by: David Faust <david.faust@oracle.com>

4 files changed, 45 insertions, 3 deletions

diff --git a/gcc/rust/backend/rust-compile-expr.cc b/gcc/rust/backend/rust-compile-expr.cc
index 0307df1..824d6d3 100644
--- a/gcc/rust/backend/rust-compile-expr.cc
+++ b/gcc/rust/backend/rust-compile-expr.cc
@@ -212,7 +212,8 @@ CompileExpr::visit (HIR::MatchExpr &expr)
     }
 
   TyTy::TypeKind scrutinee_kind = scrutinee_expr_tyty->get_kind ();
-  rust_assert (scrutinee_kind == TyTy::TypeKind::BOOL
+  rust_assert ((TyTy::is_primitive_type_kind (scrutinee_kind)
+		&& scrutinee_kind != TyTy::TypeKind::NEVER)
 	       || scrutinee_kind == TyTy::TypeKind::ADT);
 
   if (scrutinee_kind == TyTy::TypeKind::ADT)
@@ -223,6 +224,13 @@ CompileExpr::visit (HIR::MatchExpr &expr)
       rust_assert (adt->is_enum ());
       rust_assert (adt->number_of_variants () > 0);
     }
+  else if (scrutinee_kind == TyTy::TypeKind::FLOAT)
+    {
+      // FIXME: CASE_LABEL_EXPR does not support floating point types.
+      // Find another way to compile these.
+      sorry_at (expr.get_locus ().gcc_location (),
+		"match on floating-point types is not yet supported");
+    }
 
   TyTy::BaseType *expr_tyty = nullptr;
   if (!ctx->get_tyctx ()->lookup_type (expr.get_mappings ().get_hirid (),
@@ -253,7 +261,7 @@ CompileExpr::visit (HIR::MatchExpr &expr)
     = CompileExpr::Compile (expr.get_scrutinee_expr ().get (), ctx);
 
   tree match_scrutinee_expr_qualifier_expr;
-  if (scrutinee_kind == TyTy::TypeKind::BOOL)
+  if (TyTy::is_primitive_type_kind (scrutinee_kind))
     {
       match_scrutinee_expr_qualifier_expr = match_scrutinee_expr;
     }
@@ -274,7 +282,7 @@ CompileExpr::visit (HIR::MatchExpr &expr)
   else
     {
       // FIXME: match on other types of expressions not yet implemented.
-      gcc_assert (0);
+      gcc_unreachable ();
     }
 
   // setup the end label so the cases can exit properly
diff --git a/gcc/rust/backend/rust-compile-pattern.cc b/gcc/rust/backend/rust-compile-pattern.cc
index e8f1c51..9c1a35a 100644
--- a/gcc/rust/backend/rust-compile-pattern.cc
+++ b/gcc/rust/backend/rust-compile-pattern.cc
@@ -89,6 +89,17 @@ CompilePatternCaseLabelExpr::visit (HIR::LiteralPattern &pattern)
 			    pattern.get_literal (), pattern.get_locus (),
 			    std::vector<AST::Attribute> ());
 
+  // Note: Floating point literals are currently accepted but will likely be
+  // forbidden in LiteralPatterns in a future version of Rust.
+  // See: https://github.com/rust-lang/rust/issues/41620
+  // For now, we cannot compile them anyway as CASE_LABEL_EXPR does not support
+  // floating point types.
+  if (pattern.get_literal ().get_lit_type () == HIR::Literal::LitType::FLOAT)
+    {
+      sorry_at (pattern.get_locus ().gcc_location (),
+		"floating-point literal in pattern");
+    }
+
   tree lit = CompileExpr::Compile (litexpr, ctx);
 
   case_label_expr = build_case_label (lit, NULL_TREE, associated_case_label);
diff --git a/gcc/rust/typecheck/rust-tyty.cc b/gcc/rust/typecheck/rust-tyty.cc
index 6b034ea..d0e8b76 100644
--- a/gcc/rust/typecheck/rust-tyty.cc
+++ b/gcc/rust/typecheck/rust-tyty.cc
@@ -114,6 +114,26 @@ TypeKindFormat::to_string (TypeKind kind)
 }
 
 bool
+is_primitive_type_kind (TypeKind kind)
+{
+  switch (kind)
+    {
+    case TypeKind::BOOL:
+    case TypeKind::CHAR:
+    case TypeKind::INT:
+    case TypeKind::UINT:
+    case TypeKind::ISIZE:
+    case TypeKind::USIZE:
+    case TypeKind::FLOAT:
+    case TypeKind::NEVER:
+    case TypeKind::STR:
+      return true;
+    default:
+      return false;
+    }
+}
+
+bool
 BaseType::satisfies_bound (const TypeBoundPredicate &predicate) const
 {
   const Resolver::TraitReference *query = predicate.get ();
diff --git a/gcc/rust/typecheck/rust-tyty.h b/gcc/rust/typecheck/rust-tyty.h
index 5f35c32..a2950e9 100644
--- a/gcc/rust/typecheck/rust-tyty.h
+++ b/gcc/rust/typecheck/rust-tyty.h
@@ -67,6 +67,9 @@ enum TypeKind
   ERROR
 };
 
+extern bool
+is_primitive_type_kind (TypeKind kind);
+
 class TypeKindFormat
 {
 public: