Merge pull request #8526 from JinShil/fix_15373

Fix Issue 15373 - Segfault when using typeid on extern(C++) class with virtual functions merged-on-behalf-of: Jacob Carlborg <jacob-carlborg@users.noreply.github.com>
dlang · Jul 30, 2018 · 2de9326 · 2de9326
2 parents 1bb0dce + 76d4781
commit 2de9326
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Showing 3 changed files with 52 additions and 6 deletions.
diff --git a/src/dmd/expressionsem.d b/src/dmd/expressionsem.d
@@ -4726,13 +4726,22 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
             ta.checkComplexTransition(exp.loc, sc);
 
         Expression e;
-        if (ea && ta.toBasetype().ty == Tclass)
+        auto tb = ta.toBasetype();
+        if (ea && tb.ty == Tclass)
         {
-            /* Get the dynamic type, which is .classinfo
-             */
-            ea = ea.expressionSemantic(sc);
-            e = new TypeidExp(ea.loc, ea);
-            e.type = Type.typeinfoclass.type;
+            if (tb.toDsymbol(sc).isClassDeclaration().classKind == ClassKind.cpp)
+            {
+                error(exp.loc, "Runtime type information is not supported for `extern(C++)` classes");
+                e = new ErrorExp();
+            }
+            else
+            {
+                /* Get the dynamic type, which is .classinfo
+                */
+                ea = ea.expressionSemantic(sc);
+                e = new TypeidExp(ea.loc, ea);
+                e.type = Type.typeinfoclass.type;
+            }
         }
         else if (ta.ty == Terror)
         {

diff --git a/test/fail_compilation/test15373.d b/test/fail_compilation/test15373.d
@@ -0,0 +1,22 @@
+/*
+TEST_OUTPUT:
+---
+fail_compilation/test15373.d(21): Error: Runtime type information is not supported for `extern(C++)` classes
+---
+*/
+
+// https://issues.dlang.org/show_bug.cgi?id=15373
+
+// Using `typeid` on an `extern(C++) class` type is ok  as it is evaluated at compile-time
+// See test/runnable/test15373.d
+
+// Using `typeid` on an `extern(C++) class` instance is not ok because `extern(C++) class`
+// instances are not rooted in `Object`
+
+extern(C++) class C { }
+
+void foo()
+{
+    C c = new C();
+    auto ti = typeid(c);
+}
diff --git a/test/runnable/test15373.d b/test/runnable/test15373.d
@@ -0,0 +1,15 @@
+// https://issues.dlang.org/show_bug.cgi?id=15373
+
+// Using `typeid` on an `extern(C++) class` type is fine as it is evaluated at compile-time
+
+// Using `typeid` on an `extern(C++) class` instance is not ok because `extern(C++) class`
+// instances are not rooted in `Object`.  See test/fail_compilation/test15373.d
+
+extern(C++) class C
+{ }
+
+void main()
+{
+    auto Cti = typeid(C);
+    assert(Cti.name == "test15373.C");
+}