[vala/0.40] codegen: Real structs are allowed by simple generics and passed as reference

[Rico Tzschichholz <ricotz src gnome org>]

commit 4f7c841ec72dd2c1226012e9caba770acc50a384
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Mon Jul 8 19:11:19 2019 +0200

    codegen: Real structs are allowed by simple generics and passed as reference
    
    Add the required pointer-indirections to fix invalid memory accesses.
    
    Fixes https://gitlab.gnome.org/GNOME/vala/issues/819

 codegen/valaccodemethodcallmodule.vala | 10 +++++++++
 tests/Makefile.am                      |  1 +
 tests/methods/varargs-gvalue.vala      | 10 +++++++++
 tests/methods/varargs-struct.vala      | 40 ++++++++++++++++++++++++++++++++++
 4 files changed, 61 insertions(+)
---
diff --git a/codegen/valaccodemethodcallmodule.vala b/codegen/valaccodemethodcallmodule.vala
index 37716c9b7..d8eabffd0 100644
--- a/codegen/valaccodemethodcallmodule.vala
+++ b/codegen/valaccodemethodcallmodule.vala
@@ -268,6 +268,10 @@ public class Vala.CCodeMethodCallModule : CCodeAssignmentModule {
                                // generic method
                                int type_param_index = 0;
                                foreach (var type_arg in ma.get_type_arguments ()) {
+                                       // real structs are passed by reference for simple generics
+                                       if (get_ccode_simple_generics (m) && type_arg.is_real_struct_type () 
&& !type_arg.nullable && !(type_arg is PointerType)) {
+                                           type_arg = new PointerType (type_arg);
+                                       }
                                        in_arg_map.set (get_param_pos (get_ccode_generic_type_pos (m) + 0.01 
* type_param_index), new CCodeIdentifier (get_ccode_name (type_arg)));
                                        type_param_index++;
                                }
@@ -765,6 +769,12 @@ public class Vala.CCodeMethodCallModule : CCodeAssignmentModule {
                        }
                }
 
+               // real structs are passed by reference for simple generics
+               if (m != null && get_ccode_simple_generics (m) && m.return_type is GenericType
+                   && expr.value_type.is_real_struct_type () && !expr.value_type.nullable && 
!(expr.value_type is PointerType)) {
+                   ccall_expr = new CCodeUnaryExpression (CCodeUnaryOperator.POINTER_INDIRECTION, new 
CCodeParenthesizedExpression (ccall_expr));
+               }
+
                if (m != null && get_ccode_type (m) != null && get_ccode_type (m) != get_ccode_name 
(m.return_type)) {
                        // Bug 699956: Implement cast for method return type if [CCode type=] annotation is 
specified
                        ccall_expr = new CCodeCastExpression (ccall_expr, get_ccode_name (m.return_type));
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 2860cc213..6ca023f0b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -138,6 +138,7 @@ TESTS = \
        methods/printf-constructor-invalid.test \
        methods/varargs-gvalue.vala \
        methods/varargs-out.vala \
+       methods/varargs-struct.vala \
        control-flow/assigned-local-variable.vala \
        control-flow/break.vala \
        control-flow/break-invalid.test \
diff --git a/tests/methods/varargs-gvalue.vala b/tests/methods/varargs-gvalue.vala
index 3160b2356..25388207f 100644
--- a/tests/methods/varargs-gvalue.vala
+++ b/tests/methods/varargs-gvalue.vala
@@ -7,9 +7,19 @@ void foo (int first_arg, ...) {
        assert (val.get_string () == "foo");
 }
 
+void faz (int first_arg, ...) {
+       var args = va_list ();
+       Value* val = args.arg ();
+
+       assert (first_arg == 23);
+       assert (val.holds (typeof (string)));
+       assert (val.get_string () == "foo");
+}
+
 void main () {
        Value val = Value (typeof (string));
        val.set_string ("foo");
 
        foo (42, val);
+       faz (23, val);
 }
diff --git a/tests/methods/varargs-struct.vala b/tests/methods/varargs-struct.vala
new file mode 100644
index 000000000..29ab4ec49
--- /dev/null
+++ b/tests/methods/varargs-struct.vala
@@ -0,0 +1,40 @@
+[CCode (has_type_id = false)]
+struct Bar {
+       public int i;
+       public int j;
+}
+
+void foo (int first_arg, ...) {
+       var args = va_list ();
+       Bar bar = args.arg ();
+
+       assert (first_arg == 42);
+       assert (bar.i == 23);
+       assert (bar.j == 4711);
+}
+
+void faz (int first_arg, ...) {
+       var args = va_list ();
+       Bar* bar = args.arg ();
+
+       assert (first_arg == 23);
+       assert (bar.i == 23);
+       assert (bar.j == 4711);
+}
+
+void fab (int first_arg, ...) {
+       var args = va_list ();
+       Bar? bar = args.arg ();
+
+       assert (first_arg == 65);
+       assert (bar.i == 23);
+       assert (bar.j == 4711);
+}
+
+void main () {
+       Bar bar = {23, 4711};
+
+       foo (42, bar);
+       faz (23, bar);
+       fab (65, bar);
+}