[PATCH] D142401: [Clang] Fix a crash when recursively callig a default member initializer.

[Corentin Jabot via Phabricator via cfe-commits]

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This fixes a regression introduced by ca61961380 <https://reviews.llvm.org/rGca619613801233ef2def8c3cc7d311d5ed0033cb>, that would lead
to a segfault due to stack exhaustion when recursively calling
a default member initializer.

Fixes #60082

I'm not able to  get clang to emit a stack exhaustion warning,
which it seems like it should be able to.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D142401

Files:
  clang/lib/Sema/SemaExpr.cpp
  clang/test/SemaCXX/cxx11-default-member-initializers.cpp


Index: clang/test/SemaCXX/cxx11-default-member-initializers.cpp
===================================================================
--- clang/test/SemaCXX/cxx11-default-member-initializers.cpp
+++ clang/test/SemaCXX/cxx11-default-member-initializers.cpp
@@ -49,3 +49,20 @@
 };
 }
 #endif
+
+// Recursively constructing default member initializers
+// should not crash clang.
+namespace GH60082 {
+
+struct A;
+
+int f(const A&) { return 42; }
+
+struct A {
+   int x = f(A());
+   A() { }
+};
+
+void foo() { A(); }
+
+}
Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -5910,7 +5910,9 @@
       *this, ExpressionEvaluationContext::PotentiallyEvaluated, Param);
   ExprEvalContexts.back().IsCurrentlyCheckingDefaultArgumentOrInitializer =
       SkipImmediateInvocations;
-  MarkDeclarationsReferencedInExpr(Init, /*SkipLocalVariables*/ true);
+  runWithSufficientStackSpace(CallLoc, [&] {
+    MarkDeclarationsReferencedInExpr(Init, /*SkipLocalVariables*/ true);
+  });
   return false;
 }
 
@@ -6008,8 +6010,11 @@
       ExprEvalContexts.back().DelayedDefaultInitializationContext = {
           CallLoc, Param, CurContext};
       EnsureImmediateInvocationInDefaultArgs Immediate(*this);
-      ExprResult Res = Immediate.TransformInitializer(Param->getInit(),
-                                                      /*NotCopy=*/false);
+      ExprResult Res;
+      runWithSufficientStackSpace(CallLoc, [&] {
+        Res = Immediate.TransformInitializer(Param->getInit(),
+                                             /*NotCopy=*/false);
+      });
       if (Res.isInvalid())
         return ExprError();
       Res = ConvertParamDefaultArgument(Param, Res.get(),
@@ -6090,9 +6095,11 @@
         NestedDefaultChecking;
 
     EnsureImmediateInvocationInDefaultArgs Immediate(*this);
-    ExprResult Res =
-        Immediate.TransformInitializer(Field->getInClassInitializer(),
-                                       /*CXXDirectInit=*/false);
+    ExprResult Res;
+    runWithSufficientStackSpace(Loc, [&] {
+      Res = Immediate.TransformInitializer(Field->getInClassInitializer(),
+                                           /*CXXDirectInit=*/false);
+    });
     if (!Res.isInvalid())
       Res = ConvertMemberDefaultInitExpression(Field, Res.get(), Loc);
     if (Res.isInvalid()) {
@@ -6105,7 +6112,9 @@
   if (Field->getInClassInitializer()) {
     Expr *E = Init ? Init : Field->getInClassInitializer();
     if (!NestedDefaultChecking)
-      MarkDeclarationsReferencedInExpr(E, /*SkipLocalVariables=*/false);
+      runWithSufficientStackSpace(Loc, [&] {
+        MarkDeclarationsReferencedInExpr(E, /*SkipLocalVariables=*/false);
+      });
     // C++11 [class.base.init]p7:
     //   The initialization of each base and member constitutes a
     //   full-expression.


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