[clang] [libclang] Add clang_Type_getDependentSizeExpr (PR #212648)

[via cfe-commits]

https://github.com/w-utter updated https://github.com/llvm/llvm-project/pull/212648

>From ded00301e58cb228a318e0c008bdcd33a4c836c7 Mon Sep 17 00:00:00 2001
From: will <104373134+w-utter at users.noreply.github.com>
Date: Wed, 29 Jul 2026 08:52:56 +1000
Subject: [PATCH] [libclang] Add clang_Type_getDependentSizeExpr

---
 clang/include/clang-c/Index.h     |  8 ++++++++
 clang/tools/libclang/CXType.cpp   | 26 ++++++++++++++++++++++++++
 clang/tools/libclang/libclang.map |  1 +
 3 files changed, 35 insertions(+)

diff --git a/clang/include/clang-c/Index.h b/clang/include/clang-c/Index.h
index 8427236e0b444..3c2ae30d9bbb9 100644
--- a/clang/include/clang-c/Index.h
+++ b/clang/include/clang-c/Index.h
@@ -3734,6 +3734,14 @@ CINDEX_LINKAGE CXType clang_Type_getModifiedType(CXType T);
  */
 CINDEX_LINKAGE CXType clang_Type_getValueType(CXType CT);
 
+
+/**
+ *  Gets the expression associated with this dependent sized array
+ *
+ *  If a non-dependent type is passed in, an invalid cursor is returned.
+ */
+CINDEX_LINKAGE CXCursor clang_Type_getDependentSizeExpr(CXType CT);
+
 /**
  * Return the offset of the field represented by the Cursor.
  *
diff --git a/clang/tools/libclang/CXType.cpp b/clang/tools/libclang/CXType.cpp
index 0063939dec423..52e813ea3c795 100644
--- a/clang/tools/libclang/CXType.cpp
+++ b/clang/tools/libclang/CXType.cpp
@@ -912,6 +912,32 @@ long long clang_getNumElements(CXType CT) {
   return result;
 }
 
+CXCursor clang_Type_getDependentSizeExpr(CXType CT) {
+  QualType T = GetQualType(CT);
+  const Type *TP = T.getTypePtrOrNull();
+
+  if (!TP)
+    return cxcursor::MakeCXCursorInvalid(CXCursor_NoDeclFound);
+
+  const Expr* E = nullptr;
+
+  switch (TP->getTypeClass()) {
+  case Type::DependentSizedArray:
+    E = cast<DependentSizedArrayType> (TP)->getSizeExpr();
+    break;
+  case Type::DependentSizedExtVector:
+    E = cast<DependentSizedExtVectorType> (TP)->getSizeExpr();
+    break;
+  default:
+    break;
+  }
+
+  if (!E) 
+    return cxcursor::MakeCXCursorInvalid(CXCursor_NoDeclFound);
+  
+  return cxcursor::MakeCXCursor(E, nullptr, GetTU(CT));
+}
+
 CXType clang_getArrayElementType(CXType CT) {
   QualType ET = QualType();
   QualType T = GetQualType(CT);
diff --git a/clang/tools/libclang/libclang.map b/clang/tools/libclang/libclang.map
index 57f281096929d..4864cb6da5929 100644
--- a/clang/tools/libclang/libclang.map
+++ b/clang/tools/libclang/libclang.map
@@ -461,6 +461,7 @@ LLVM_23 {
   global:
     clang_ModuleCache_prune;
     clang_ModuleCache_pruneWithCallback;
+    clang_Type_getDependentSizeExpr;
 };
 
 # Example of how to add a new symbol version entry.  If you do add a new symbol