Commit 09a78d6235

@@ -421,9 +421,17 @@ static TypeTableEntry * analyze_expression(CodeGen *g, ImportTableEntry *import,
 
                 TypeTableEntry *explicit_type = variable_declaration->type != nullptr ?
                     resolve_type(g, variable_declaration->type) : nullptr;
+                if (explicit_type == g->builtin_types.entry_unreachable) {
+                    add_node_error(g, variable_declaration->type,
+                        buf_sprintf("variable of type 'unreachable' is not allowed."));
+                }
 
                 TypeTableEntry *implicit_type = variable_declaration->expr != nullptr ?
                     analyze_expression(g, import, context, explicit_type, variable_declaration->expr) : nullptr;
+                if (implicit_type == g->builtin_types.entry_unreachable) {
+                    add_node_error(g, node,
+                        buf_sprintf("variable initialization is unreachable."));
+                }
 
                 if (implicit_type == nullptr) {
                     add_node_error(g, node, buf_sprintf("initial values are required for variable declaration."));
@@ -715,6 +723,11 @@ static void analyze_top_level_declaration(CodeGen *g, ImportTableEntry *import,
                     assert(param_decl->type->type == NodeTypeType);
                     TypeTableEntry *type = param_decl->type->codegen_node->data.type_node.entry;
 
+                    if (type == g->builtin_types.entry_unreachable) {
+                        add_node_error(g, param_decl->type,
+                            buf_sprintf("parameter of type 'unreachable' is not allowed."));
+                    }
+
                     LocalVariableTableEntry *variable_entry = allocate<LocalVariableTableEntry>(1);
                     buf_init_from_buf(&variable_entry->name, &param_decl->name);
                     variable_entry->type = type;

@@ -404,6 +404,22 @@ fn f() {
 }
     )SOURCE", 1, ".tmp_source.zig:3:9: error: type mismatch. expected bool. got i32");
 
+    add_compile_fail_case("assign unreachable", R"SOURCE(
+fn f() {
+    let a = return;
+}
+    )SOURCE", 1, ".tmp_source.zig:3:5: error: variable initialization is unreachable.");
+
+    add_compile_fail_case("unreachable variable", R"SOURCE(
+fn f() {
+    let a : unreachable = return;
+}
+    )SOURCE", 1, ".tmp_source.zig:3:13: error: variable of type 'unreachable' is not allowed.");
+
+    add_compile_fail_case("unreachable parameter", R"SOURCE(
+fn f(a : unreachable) {}
+    )SOURCE", 1, ".tmp_source.zig:2:10: error: parameter of type 'unreachable' is not allowed.");
+
 }
 
 static void print_compiler_invocation(TestCase *test_case, Buf *zig_stderr) {