conv: Add return conversion pattern.

lib/vast/Conversion/Parser/ToParser.cpp

@@ -258,6 +258,20 @@ namespace vast::conv {
                 : base(mctx), models(models)
             {}
 
+            static std::optional< function_model > get_model(
+                const function_models &models, string_ref name
+            ) {
+                if (auto kv = models.find(name); kv != models.end()) {
+                    return kv->second;
+                }
+
+                return std::nullopt;
+            }
+
+            std::optional< function_model > get_model(string_ref name) const {
+                return get_model(models, name);
+            }
+
             const function_models &models;
         };
 
@@ -408,34 +422,60 @@ namespace vast::conv {
             }
         };
 
-        struct FuncConversion
-            : parser_conversion_pattern_base< hl::FuncOp >
-            , tc::op_type_conversion< hl::FuncOp, function_type_converter >
+        struct ReturnConversion
+            : parser_conversion_pattern_base< hl::ReturnOp >
         {
-            using op_t = hl::FuncOp;
+            using op_t = hl::ReturnOp;
             using base = parser_conversion_pattern_base< op_t >;
             using base::base;
 
             using adaptor_t = typename op_t::Adaptor;
 
-            static std::optional< function_model > get_model(
-                const function_models &models, op_t op
-            ) {
-                if (auto kv = models.find(op.getSymName()); kv != models.end()) {
-                    return kv->second;
-                }
+            logical_result matchAndRewrite(
+                op_t op, adaptor_t adaptor, conversion_rewriter &rewriter
+            ) const override {
+                auto func = op->getParentOfType< hl::FuncOp >();
+                auto model = get_model(func.getSymName());
 
-                return std::nullopt;
+                auto rty = model
+                    ? model->get_return_type(rewriter.getContext())
+                    : pr::MaybeDataType::get(rewriter.getContext());
+
+                rewriter.replaceOpWithNewOp< op_t >(
+                    op, convert_value_types(adaptor.getOperands(), rty, rewriter)
+                );
+
+                return mlir::success();
             }
 
-            std::optional< function_model > get_model(op_t op) const {
-                return get_model(models, op);
+            static void legalize(parser_conversion_config &cfg) {
+                cfg.target.addLegalOp< mlir::UnrealizedConversionCastOp >();
+                cfg.target.addDynamicallyLegalOp< op_t >([](op_t op) {
+                    for (auto ty : op.getResult().getType()) {
+                        if (!is_parser_type(ty)) {
+                            return false;
+                        }
+                    }
+                    return true;
+                });
             }
+        };
+
+        struct FuncConversion
+            : parser_conversion_pattern_base< hl::FuncOp >
+            , tc::op_type_conversion< hl::FuncOp, function_type_converter >
+        {
+            using op_t = hl::FuncOp;
+            using base = parser_conversion_pattern_base< op_t >;
+            using base::base;
+
+            using adaptor_t = typename op_t::Adaptor;
+
 
             logical_result matchAndRewrite(
                 op_t op, adaptor_t adaptor, conversion_rewriter &rewriter
             ) const override {
-                auto tc = function_type_converter(*rewriter.getContext(), get_model(op));
+                auto tc = function_type_converter(*rewriter.getContext(), get_model(op.getSymName()));
                 if (auto func_op = mlir::dyn_cast< core::function_op_interface >(op.getOperation())) {
                     return this->replace(func_op, rewriter, tc);
                 }
@@ -447,7 +487,7 @@ namespace vast::conv {
                 cfg.target.addLegalOp< mlir::UnrealizedConversionCastOp >();
                 cfg.target.addDynamicallyLegalOp< op_t >([models = cfg.models](op_t op) {
                     return function_type_converter(
-                        *op.getContext(), get_model(models, op)
+                        *op.getContext(), get_model(models, op.getSymName())
                     ).isLegal(op.getFunctionType());
                 });
             }
@@ -459,6 +499,7 @@ namespace vast::conv {
             FuncConversion,
             ParamConversion,
             DeclRefConversion,
+            ReturnConversion,
             CallConversion
         >;