Adapt format.py for attribute conditionals

Allows format.py to format & and | separated conditionals in
attribute value fields.

Bug: 378692747
Change-Id: I0d9b1eb7b47c3a4052729379c2579b9322997c69
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6020699
Commit-Queue: Alex Gough <ajgo@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1383207}

mojo/public/tools/mojom/mojom/format/format.py

@@ -145,6 +145,10 @@ def _format_attribute_list(node, indent, newline=True):
                 lw.write('"')
                 lw.write(attr.value.replace('"', '\\"'))
                 lw.write('"')
+            elif isinstance(attr.value, ast.AttributeValueOrList):
+                lw.write('|'.join(x.name for x in attr.value))
+            elif isinstance(attr.value, ast.AttributeValueAndList):
+                lw.write('&'.join(x.name for x in attr.value))
             else:
                 raise ValueError(
                     f'Unxpected value type {type(attr.value)} for {attr}')

mojo/public/tools/mojom/mojom/format/testdata/attributes.in

@@ -9,3 +9,9 @@ struct Struct {
   // Another field.
   [ShouldWeEscapeQuotes="did you say\"yes?\""] string c@3; // End comment.
 };
+
+[EnableIf=is_one|is_two]
+struct Struct {
+  [EnableIfNot=is_one&is_blue]
+  string field;
+};

mojo/public/tools/mojom/mojom/format/testdata/attributes.out

@@ -11,3 +11,9 @@ struct Struct {
   [ShouldWeEscapeQuotes="did you say\"yes?\""]
   string c@3;  // End comment.
 };
+
+[EnableIf=is_one|is_two]
+struct Struct {
+  [EnableIfNot=is_one&is_blue]
+  string field;
+};