[clang] 2fbf18b - [clang] Fix aggregate initialization inside lambda constexpr

[Mariya Podchishchaeva via cfe-commits]

Author: Mariya Podchishchaeva
Date: 2023-03-06T03:38:49-05:00
New Revision: 2fbf18b40026b46bd380fae58575cebbd9801ff4

URL: https://github.com/llvm/llvm-project/commit/2fbf18b40026b46bd380fae58575cebbd9801ff4
DIFF: https://github.com/llvm/llvm-project/commit/2fbf18b40026b46bd380fae58575cebbd9801ff4.diff

LOG: [clang] Fix aggregate initialization inside lambda constexpr

Constant evaluator only considered access to `this` pointer to be
possible if `this` poitners was captured. However `this` can also appear if
there was a default member initializer.

Fixes https://github.com/llvm/llvm-project/issues/60936

Reviewed By: shafik

Differential Revision: https://reviews.llvm.org/D144866

Added: 
    

Modified: 
    clang/docs/ReleaseNotes.rst
    clang/lib/AST/ExprConstant.cpp
    clang/test/SemaCXX/lambda-expressions.cpp

Removed: 
    


################################################################################
diff  --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 988bcf1860987..cd91fbe78bb2b 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -178,6 +178,8 @@ Bug Fixes in This Version
   (`#57682 <https://github.com/llvm/llvm-project/issues/57682>`_)
 - Clang now support export declarations in the language linkage.
   (`#60405 <https://github.com/llvm/llvm-project/issues/60405>`_)
+- Fix aggregate initialization inside lambda constexpr.
+  (`#60936 <https://github.com/llvm/llvm-project/issues/60936>`_)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

diff  --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 9e67f862ae634..6b0beb1973893 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -8758,16 +8758,19 @@ class PointerExprEvaluator
       return false;
     }
     Result = *Info.CurrentCall->This;
-    // If we are inside a lambda's call operator, the 'this' expression refers
-    // to the enclosing '*this' object (either by value or reference) which is
-    // either copied into the closure object's field that represents the '*this'
-    // or refers to '*this'.
+
     if (isLambdaCallOperator(Info.CurrentCall->Callee)) {
-      // Ensure we actually have captured 'this'. (an error will have
-      // been previously reported if not).
+      // Ensure we actually have captured 'this'. If something was wrong with
+      // 'this' capture, the error would have been previously reported.
+      // Otherwise we can be inside of a default initialization of an object
+      // declared by lambda's body, so no need to return false.
       if (!Info.CurrentCall->LambdaThisCaptureField)
-        return false;
+        return true;
 
+      // If we have captured 'this',  the 'this' expression refers
+      // to the enclosing '*this' object (either by value or reference) which is
+      // either copied into the closure object's field that represents the
+      // '*this' or refers to '*this'.
       // Update 'Result' to refer to the data member/field of the closure object
       // that represents the '*this' capture.
       if (!HandleLValueMember(Info, E, Result,

diff  --git a/clang/test/SemaCXX/lambda-expressions.cpp b/clang/test/SemaCXX/lambda-expressions.cpp
index 0c19d94e8bd9f..84d224fdc835e 100644
--- a/clang/test/SemaCXX/lambda-expressions.cpp
+++ b/clang/test/SemaCXX/lambda-expressions.cpp
@@ -689,3 +689,18 @@ void Func1() {
 }
 
 }
+
+#if __cplusplus > 201402L
+namespace GH60936 {
+struct S {
+  int i;
+  // `&i` in default initializer causes implicit `this` access.
+  int *p = &i;
+};
+
+static_assert([]() constexpr {
+  S r = S{2};
+  return r.p != nullptr;
+}());
+} // namespace GH60936
+#endif