[clang] Fixed Constant Evaluation don't Call Destructor

[Mr-Anyone]

Within the condition statement of the for block, the destructor doesn't get when evaluating compile time constants.

resolves #139818

[llvmbot]

@llvm/pr-subscribers-clang

Author: Vincent (Mr-Anyone)

Changes

Within the condition statement of the for block, the destructor doesn't get when evaluating compile time constants.

resolves #139818

---

Full diff: https://github.com/llvm/llvm-project/pull/140278.diff

3 Files Affected:

• (modified) clang/docs/ReleaseNotes.rst (+1)
• (modified) clang/lib/AST/ExprConstant.cpp (+5-1)
• (modified) clang/test/SemaCXX/static-assert-cxx26.cpp (+35)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 0c12091a90add..76c139632b31c 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -623,6 +623,7 @@ Bug Fixes in This Version
 - Fix crash due to unknown references and pointer implementation and handling of
   base classes. (GH139452)
 - Fixed an assertion failure in serialization of constexpr structs containing unions. (#GH140130)
+- Fix constant evaluation in for loop not calling destructor (#GH139818)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index ca1fbdf7e652f..d8364977258a1 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -5742,8 +5742,12 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
       if (FS->getCond() && !EvaluateCond(Info, FS->getConditionVariable(),
                                          FS->getCond(), Continue))
         return ESR_Failed;
-      if (!Continue)
+
+      if (!Continue) {
+        if (!IterScope.destroy())
+          return ESR_Failed;
         break;
+      }
 
       EvalStmtResult ESR = EvaluateLoopBody(Result, Info, FS->getBody());
       if (ESR != ESR_Continue) {
diff --git a/clang/test/SemaCXX/static-assert-cxx26.cpp b/clang/test/SemaCXX/static-assert-cxx26.cpp
index b53c67ee67932..7a47f2784ceb3 100644
--- a/clang/test/SemaCXX/static-assert-cxx26.cpp
+++ b/clang/test/SemaCXX/static-assert-cxx26.cpp
@@ -416,3 +416,38 @@ static_assert(
       // expected-note@-1 {{read of dereferenced one-past-the-end pointer is not allowed in a constant expression}}
 );
 }
+
+// taken from: https://github.com/llvm/llvm-project/issues/139818
+namespace GH139818{
+    struct A {
+      constexpr ~A() { ref = false; }
+      constexpr operator bool() {
+        return b;
+      }
+      bool b;
+      bool& ref;
+    };
+
+    constexpr bool f1() {
+      bool ret = true;
+      for (bool b = false; A x{b, ret}; b = true) {}
+      return ret;
+    }
+
+    static_assert(!f1());
+
+    struct Y {
+      constexpr ~Y() noexcept(false) { throw "oops"; }  // expected-error {{cannot use 'throw' with exceptions disabled}}
+                                                        // expected-note@-1 {{subexpression not valid in a constant expression}}
+      constexpr operator bool() {
+        return b;
+      }
+      bool b;
+    };
+    constexpr bool f2() {
+      for (bool b = false; Y x = {b}; b = true) {} // expected-note {{in call to 'x.~Y()'}}
+      return true;
+    }
+    static_assert(f2()); // expected-error {{static assertion expression is not an integral constant expression}}
+                         // expected-note@-1 {{in call to 'f2()'}}
+};

[Mr-Anyone]

ping

[Mr-Anyone]

Documentation fail seems to be fixed by #142387

[Sirraide]

One comment but otherwise this LGTM.

[Sirraide]

Documentation fail seems to be fixed by #142387

Yeah, the changes to the release notes look fine, so if CI is unhappy about them then that’s for some other reason.

[Mr-Anyone]

@Sirraide I don't have merge access. Could you please merge? Thanks.