codegen: Don't append unreachable clean-up section of Block

Found by -Werror=unreachable-code

See https://gitlab.gnome.org/GNOME/vala/issues/838

diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index 1e2b4b38e796af5878cfecef57893c49fd0acfb3..5b8140be0a201719928916ecdc904b40f29d1746 100644 (file)
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -2325,7 +2325,13 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
                        }
                }
 
-               if (b.parent_symbol is Method) {
+               bool unreachable_exit_block = false;
+               if (b.parent_symbol is Subroutine) {
+                       unowned BasicBlock? exit_block = ((Subroutine) b.parent_symbol).exit_block;
+                       unreachable_exit_block = (exit_block == null || exit_block.get_predecessors ().size <= 0);
+               }
+
+               if (!unreachable_exit_block && b.parent_symbol is Method) {
                        var m = (Method) b.parent_symbol;
                        foreach (Parameter param in m.get_parameters ()) {
                                if (!param.captured && !param.ellipsis && requires_destroy (param.variable_type) && param.direction == ParameterDirection.IN) {
@@ -2338,14 +2344,14 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
                        foreach (var postcondition in m.get_postconditions ()) {
                                create_postcondition_statement (postcondition);
                        }
-               } else if (b.parent_symbol is PropertyAccessor) {
+               } else if (!unreachable_exit_block && b.parent_symbol is PropertyAccessor) {
                        var acc = (PropertyAccessor) b.parent_symbol;
                        if (acc.value_parameter != null && !acc.value_parameter.captured && requires_destroy (acc.value_parameter.variable_type)) {
                                ccode.add_expression (destroy_parameter (acc.value_parameter));
                        }
                }
 
-               if (b.captured) {
+               if (!unreachable_exit_block && b.captured) {
                        int block_id = get_block_id (b);
 
                        var data_unref = new CCodeFunctionCall (new CCodeIdentifier ("block%d_data_unref".printf (block_id)));