[clang-format] Add BracedInitializerIndentWidth option

The option allows users to specify how many columns to use to indent
the contents of initializer lists.

Closes #51070.

Differential Revision: https://reviews.llvm.org/D146101

3 files changed, 46 insertions, 4 deletions

diff --git a/clang/docs/ClangFormatStyleOptions.rst b/clang/docs/ClangFormatStyleOptions.rst
index 2e9038933c81..bdcd1e88d240 100644
--- a/clang/docs/ClangFormatStyleOptions.rst
+++ b/clang/docs/ClangFormatStyleOptions.rst
@@ -1829,6 +1829,41 @@ the configuration (without a prefix: ``Auto``).
                            }
 
 
+.. _BracedInitializerIndentWidth:
+
+**BracedInitializerIndentWidth** (``Unsigned``) :versionbadge:`clang-format 17` :ref:`¶ <BracedInitializerIndentWidth>`
+  The number of columns to use to indent the contents of braced init lists.
+  If unset, ``ContinuationIndentWidth`` is used.
+
+  .. code-block:: c++
+
+    AlignAfterOpenBracket: AlwaysBreak
+    BracedInitializerIndentWidth: 2
+
+    void f() {
+      SomeClass c{
+        "foo",
+        "bar",
+        "baz",
+      };
+      auto s = SomeStruct{
+        .foo = "foo",
+        .bar = "bar",
+        .baz = "baz",
+      };
+      SomeArrayT a[3] = {
+        {
+          foo,
+          bar,
+        },
+        {
+          foo,
+          bar,
+        },
+        SomeArrayT{},
+      };
+    }
+
 .. _BreakAfterAttributes:
 
 **BreakAfterAttributes** (``AttributeBreakingStyle``) :versionbadge:`clang-format 16` :ref:`¶ <BreakAfterAttributes>`
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 55fc0e6c790b..d66993b0929f 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -513,6 +513,8 @@ clang-format
 - Add additional Qualifier Ordering support for special cases such
   as templates, requires clauses, long qualified names.
 - Fix all known issues associated with ``LambdaBodyIndentation: OuterScope``.
+- Add ``BracedInitializerIndentWidth`` which can be used to configure
+  the indentation level of the contents of braced init lists.
 
 libclang
 --------
diff --git a/clang/docs/tools/dump_format_style.py b/clang/docs/tools/dump_format_style.py
index fe6e9147ee94..7b032894ce62 100755
--- a/clang/docs/tools/dump_format_style.py
+++ b/clang/docs/tools/dump_format_style.py
@@ -69,9 +69,13 @@ def to_yaml_type(typestr: str):
   elif typestr == 'std::string':
     return 'String'
 
-  subtype, napplied = re.subn(r'^std::vector<(.*)>$', r'\1', typestr)
-  if napplied == 1:
-    return 'List of ' + pluralize(to_yaml_type(subtype))
+  match = re.match(r'std::vector<(.*)>$', typestr)
+  if match:
+    return 'List of ' + pluralize(to_yaml_type(match.group(1)))
+
+  match = re.match(r'std::optional<(.*)>$', typestr)
+  if match:
+    return to_yaml_type(match.group(1))
 
   return typestr
 
@@ -331,7 +335,8 @@ class OptionsReader:
       if option.type not in ['bool', 'unsigned', 'int', 'std::string',
                              'std::vector<std::string>',
                              'std::vector<IncludeCategory>',
-                             'std::vector<RawStringFormat>']:
+                             'std::vector<RawStringFormat>',
+                             'std::optional<unsigned>']:
         if option.type in enums:
           option.enum = enums[option.type]
         elif option.type in nested_structs: