[PATCH] D133948: [clang][C++20] Fix clang/clangd assert/crash after compilation errors

[Dmitry Polukhin via Phabricator via llvm-commits]

DmitryPolukhin updated this revision to Diff 460437.
DmitryPolukhin added a comment.

clang-format


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D133948/new/

https://reviews.llvm.org/D133948

Files:
  clang/lib/Sema/SemaExpr.cpp
  clang/test/SemaCXX/remove-nested-immediate-invocation-crash.cpp


Index: clang/test/SemaCXX/remove-nested-immediate-invocation-crash.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/remove-nested-immediate-invocation-crash.cpp
@@ -0,0 +1,11 @@
+// RUN: not %clang_cc1 -fsyntax-only -verify -std=gnu++20 -ferror-limit 19 %s
+// Creduced test case for the crash in RemoveNestedImmediateInvocation after compliation errros.
+
+a, class b {                               template < typename c>                 consteval b(c
+} template <typename...> using d = b;
+auto e(d<>) -> int:;
+}
+f
+}
+g() {
+                    auto h = "":(::i(e(h))
Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -17624,9 +17624,13 @@
     Transformer.AllowSkippingFirstCXXConstructExpr = false;
 
   ExprResult Res = Transformer.TransformExpr(It->getPointer()->getSubExpr());
-  assert(Res.isUsable());
-  Res = SemaRef.MaybeCreateExprWithCleanups(Res);
-  It->getPointer()->setSubExpr(Res.get());
+  // The result may not be usable in case of previous compilation errors.
+  // In this case evaluation of the expression may result in crash so just
+  // don't do anything further with the result.
+  if (Res.isUsable()) {
+    Res = SemaRef.MaybeCreateExprWithCleanups(Res);
+    It->getPointer()->setSubExpr(Res.get());
+  }
 }
 
 static void


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