utils: ipc: Add support for Flags

Add Flags<E> as a supported type in the IPA interface.

It is used in mojom with the [flags] attribute. Any field or parameter
type E that is prefixed with the [flags] attribute will direct the code
generator to generate the type name "Flags<E>" and appropriate
serialization/deserialization code for Flags<E> instead of for E.

It is usable and has been tested in struct members, function input and
output parameters, and Signal parameters. This does not add support for
returning Flags as direct return values.

Additionally, the [scopedEnum] attribute can be used on enum
definitions, which will instruct the code generator to convert it to an
enum class instead of a raw enum.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 36 insertions, 5 deletions

diff --git a/utils/ipc/generators/mojom_libcamera_generator.py b/utils/ipc/generators/mojom_libcamera_generator.py
index 753bfc73..442f797c 100644
--- a/utils/ipc/generators/mojom_libcamera_generator.py
+++ b/utils/ipc/generators/mojom_libcamera_generator.py
@@ -74,6 +74,8 @@ def GetDefaultValue(element):
         return element.default
     if type(element.kind) == mojom.Kind:
         return '0'
+    if IsFlags(element):
+        return ''
     if mojom.IsEnumKind(element.kind):
         return f'static_cast<{element.kind.mojom_name}>(0)'
     if isinstance(element.kind, mojom.Struct) and \
@@ -184,7 +186,7 @@ def MethodParameters(method):
     params = []
     for param in method.parameters:
         params.append('const %s %s%s' % (GetNameForElement(param),
-                                         '&' if not IsPod(param) else '',
+                                         '' if IsPod(param) or IsEnum(param) else '&',
                                          param.mojom_name))
     for param in MethodParamOutputs(method):
         params.append(f'{GetNameForElement(param)} *{param.mojom_name}')
@@ -220,9 +222,30 @@ def IsControls(element):
 def IsEnum(element):
     return mojom.IsEnumKind(element.kind)
 
+
+# Only works the enum definition, not types
+def IsScoped(element):
+    attributes = getattr(element, 'attributes', None)
+    if not attributes:
+        return False
+    return 'scopedEnum' in attributes
+
+
+def IsEnumScoped(element):
+    if not IsEnum(element):
+        return False
+    return IsScoped(element.kind)
+
 def IsFd(element):
     return mojom.IsStructKind(element.kind) and element.kind.mojom_name == "SharedFD"
 
+
+def IsFlags(element):
+    attributes = getattr(element, 'attributes', None)
+    if not attributes:
+        return False
+    return 'flags' in attributes
+
 def IsMap(element):
     return mojom.IsMapKind(element.kind)
 
@@ -251,9 +274,11 @@ def ByteWidthFromCppType(t):
         raise Exception('invalid type')
     return str(int(_bit_widths[key]) // 8)
 
-
 # Get the type name for a given element
 def GetNameForElement(element):
+    # Flags
+    if IsFlags(element):
+        return f'Flags<{GetFullNameForElement(element.kind)}>'
     # structs
     if (mojom.IsEnumKind(element) or
         mojom.IsInterfaceKind(element) or
@@ -302,15 +327,18 @@ def GetNameForElement(element):
 def GetFullNameForElement(element):
     name = GetNameForElement(element)
     namespace_str = ''
-    if mojom.IsStructKind(element):
+    if (mojom.IsStructKind(element) or mojom.IsEnumKind(element)):
         namespace_str = element.module.mojom_namespace.replace('.', '::')
     elif (hasattr(element, 'kind') and
-             (mojom.IsStructKind(element.kind) or
-              mojom.IsEnumKind(element.kind))):
+          (mojom.IsStructKind(element.kind) or mojom.IsEnumKind(element.kind))):
         namespace_str = element.kind.module.mojom_namespace.replace('.', '::')
 
     if namespace_str == '':
         return name
+
+    if IsFlags(element):
+        return GetNameForElement(element)
+
     return f'{namespace_str}::{name}'
 
 def ValidateZeroLength(l, s, cap=True):
@@ -407,10 +435,13 @@ class Generator(generator.Generator):
             'is_array': IsArray,
             'is_controls': IsControls,
             'is_enum': IsEnum,
+            'is_enum_scoped': IsEnumScoped,
             'is_fd': IsFd,
+            'is_flags': IsFlags,
             'is_map': IsMap,
             'is_plain_struct': IsPlainStruct,
             'is_pod': IsPod,
+            'is_scoped': IsScoped,
             'is_str': IsStr,
             'method_input_has_fd': MethodInputHasFd,
             'method_output_has_fd': MethodOutputHasFd,