[clang] [Clang] prevent assertion failure by skipping analysis of invalid field declaration (PR #99998)

[Oleksandr T. via cfe-commits]

https://github.com/a-tarasyuk created https://github.com/llvm/llvm-project/pull/99998

Fixes #99868

>From 17f20934a971f058c8befd3a7bd850bd2c59a78c Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk at outlook.com>
Date: Tue, 23 Jul 2024 02:04:26 +0300
Subject: [PATCH] [Clang] prevent assertion failure by skipping analysis of
 invalid field declaration

---
 clang/docs/ReleaseNotes.rst                            |  1 +
 clang/lib/AST/DeclCXX.cpp                              |  3 +++
 .../test/CXX/temp/temp.arg/temp.arg.template/p3-0x.cpp | 10 ++++++++++
 3 files changed, 14 insertions(+)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 9a07ad42b8f6f..bd4d65b8dd1b9 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -1105,6 +1105,7 @@ Bug Fixes to C++ Support
 - Clang now diagnoses explicit object parameters in member pointers and other contexts where they should not appear.
   Fixes (#GH85992).
 - Fixed a crash-on-invalid bug involving extraneous template parameter with concept substitution. (#GH73885)
+- Fixed assertion failure by skipping the analysis of an invalid field declaration. (#GH99868)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 72d68f39a97a5..b573c2713a3aa 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -675,6 +675,9 @@ bool CXXRecordDecl::hasSubobjectAtOffsetZeroOfEmptyBaseType(
       if (!IsFirstField && !FD->isZeroSize(Ctx))
         continue;
 
+      if (FD->isInvalidDecl())
+        continue;
+
       //   -- If X is n array type, [visit the element type]
       QualType T = Ctx.getBaseElementType(FD->getType());
       if (auto *RD = T->getAsCXXRecordDecl())
diff --git a/clang/test/CXX/temp/temp.arg/temp.arg.template/p3-0x.cpp b/clang/test/CXX/temp/temp.arg/temp.arg.template/p3-0x.cpp
index 51489c5eac5ad..19793fe826372 100644
--- a/clang/test/CXX/temp/temp.arg/temp.arg.template/p3-0x.cpp
+++ b/clang/test/CXX/temp/temp.arg/temp.arg.template/p3-0x.cpp
@@ -38,3 +38,13 @@ X1<int, X1a> inst_x1a;
 X1<long, X1b> inst_x1b;
 X1<short, X1c> inst_x1c;
 X1<short, X1d> inst_x1d; // expected-error{{template template argument has different template parameters than its corresponding template template paramete}}
+
+template <int> class X2; // expected-note{{template is declared here}} \
+                         // expected-note{{template is declared here}}
+class X3 : X2<1> {}; // expected-error{{implicit instantiation of undefined template 'X2<1>'}}
+
+template <int> class X4 : X3 {
+  struct {
+    X2<1> e; // expected-error{{implicit instantiation of undefined template 'X2<1>'}}
+  } f;
+};