[vala/0.36: 50/212] codegen: Adjust format-index for printf/scanf-methods which throw errors

[Rico Tzschichholz <ricotz src gnome org>]

commit 85b8b81c3e9b86d04ff83a899b6c4a36442e23fa
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Sun Aug 27 09:11:48 2017 +0200

    codegen: Adjust format-index for printf/scanf-methods which throw errors
    
    If there is no explicit FormatArg annotation while this method throws an
    error, it is required to mark the parameter located right before ellipsis
    as format-arg to account for the parameter shifting caused by the inserted
    GError parameter.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=781061

 codegen/valaccodemethodmodule.vala |   15 ++++++++++++++-
 tests/Makefile.am                  |    1 +
 tests/methods/bug781061.vala       |   30 ++++++++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 1 deletions(-)
---
diff --git a/codegen/valaccodemethodmodule.vala b/codegen/valaccodemethodmodule.vala
index 4d0d5fb..a4fcb12 100644
--- a/codegen/valaccodemethodmodule.vala
+++ b/codegen/valaccodemethodmodule.vala
@@ -1031,6 +1031,9 @@ public abstract class Vala.CCodeMethodModule : CCodeStructModule {
                        }
                }
 
+               var needs_format_arg = m.get_format_arg_index () < 0 && (m.printf_format || m.scanf_format);
+
+               CCodeParameter? prev_cparam = null;
                foreach (Parameter param in m.get_parameters ()) {
                        if (param.direction != ParameterDirection.OUT) {
                                if ((direction & 1) == 0) {
@@ -1044,7 +1047,17 @@ public abstract class Vala.CCodeMethodModule : CCodeStructModule {
                                }
                        }
 
-                       generate_parameter (param, decl_space, cparam_map, carg_map);
+                       var cparam = generate_parameter (param, decl_space, cparam_map, carg_map);
+
+                       // if there is no explicit FormatArg annotation while this method throws an error
+                       // it is required to mark the parameter located right before ellipsis as format-arg
+                       // to account for the parameter shifting caused by the inserted GError parameter
+                       if (needs_format_arg) {
+                               if (prev_cparam != null && cparam.ellipsis) {
+                                       prev_cparam.modifiers |= CCodeModifiers.FORMAT_ARG;
+                               }
+                               prev_cparam = cparam;
+                       }
                }
 
                if ((direction & 2) != 0) {
diff --git a/tests/Makefile.am b/tests/Makefile.am
index c5cc723..16724e3 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -92,6 +92,7 @@ TESTS = \
        methods/bug771964.vala \
        methods/bug774060.vala \
        methods/bug775466.test \
+       methods/bug781061.vala \
        methods/generics.vala \
        methods/printf-invalid.test \
        methods/printf-constructor.vala \
diff --git a/tests/methods/bug781061.vala b/tests/methods/bug781061.vala
new file mode 100644
index 0000000..0969935
--- /dev/null
+++ b/tests/methods/bug781061.vala
@@ -0,0 +1,30 @@
+errordomain FooError {
+       FAILED;
+}
+
+[PrintfFormat]
+void print_something_throws (bool ok, string format, ...) throws FooError {
+       var vargs = va_list ();
+       print_something_vargs_throws (ok, format, vargs);
+}
+
+[PrintfFormat]
+void print_something_vargs_throws (bool ok, string format, va_list vargs) throws FooError {
+}
+
+[ScanfFormat]
+void scan_something_throws (bool ok, string format, ...) throws FooError {
+}
+
+[ScanfFormat]
+void scan_something_vargs_throws (bool ok, string format, va_list vargs) throws FooError {
+}
+
+void main () {
+       try {
+               print_something_throws (true, "%s", "foo");
+               int i;
+               scan_something_throws (false, "%d", out i);
+       } catch (FooError e) {
+       }
+}