Delete implicit members whose definition does not compile

Author: lucic71

cpp2rust/converter/converter_lib.cpp

@@ -1636,27 +1636,42 @@ void DefineImplicitMembers(clang::Sema &sema, clang::CXXRecordDecl *decl) {
   tu_scope.setEntity(sema.Context.getTranslationUnitDecl());
   auto *saved_tu_scope = std::exchange(sema.TUScope, &tu_scope);
   sema.ForceDeclarationOfImplicitMembers(decl);
+  auto define = [&](clang::FunctionDecl *fn, auto &&definer) {
+    RuleDecls::Trial trial(sema);
+    definer();
+    if (trial.failed()) {
+      fn->setDeletedAsWritten(true);
+    }
+  };
   for (auto ctor : decl->ctors()) {
     if (ctor->isCopyConstructor() && ctor->isImplicit() &&
         !ctor->doesThisDeclarationHaveABody() && !ctor->isDeleted()) {
-      sema.DefineImplicitCopyConstructor(decl->getLocation(), ctor);
+      define(ctor, [&] {
+        sema.DefineImplicitCopyConstructor(decl->getLocation(), ctor);
+      });
     }
     if (ctor->isMoveConstructor() && !ctor->isUserProvided() &&
         !ctor->doesThisDeclarationHaveABody() && !ctor->isDeleted() &&
         !HasDefaultedCopyConstructor(decl)) {
-      sema.DefineImplicitMoveConstructor(decl->getLocation(), ctor);
+      define(ctor, [&] {
+        sema.DefineImplicitMoveConstructor(decl->getLocation(), ctor);
+      });
     }
   }
   for (auto *method : decl->methods()) {
     if (method->isMoveAssignmentOperator() && !method->isUserProvided() &&
         !method->doesThisDeclarationHaveABody() && !method->isDeleted() &&
         !HasDefaultedCopyAssignment(decl)) {
-      sema.DefineImplicitMoveAssignment(decl->getLocation(), method);
+      define(method, [&] {
+        sema.DefineImplicitMoveAssignment(decl->getLocation(), method);
+      });
     }
     if (method->isCopyAssignmentOperator() && !method->isUserProvided() &&
         !method->doesThisDeclarationHaveABody() && !method->isDeleted() &&
         NeedsDefaultedCopyAssignment(decl)) {
-      sema.DefineImplicitCopyAssignment(decl->getLocation(), method);
+      define(method, [&] {
+        sema.DefineImplicitCopyAssignment(decl->getLocation(), method);
+      });
     }
   }
   auto define_defaulted_comparison = [&](clang::FunctionDecl *fn) {
@@ -1669,7 +1684,9 @@ void DefineImplicitMembers(clang::Sema &sema, clang::CXXRecordDecl *decl) {
 #else
     auto kind = sema.getDefaultedComparisonKind(fn);
 #endif
-    sema.DefineDefaultedComparison(decl->getLocation(), fn, kind);
+    define(fn, [&] {
+      sema.DefineDefaultedComparison(decl->getLocation(), fn, kind);
+    });
   };
   for (auto *method : decl->methods()) {
     define_defaulted_comparison(method);

tests/unit/copy_move_deleted.cpp

@@ -1,5 +1,6 @@
 #include <cassert>
 #include <utility>
+#include <vector>
 
 struct NoCopy {
   int v;
@@ -43,6 +44,10 @@ struct Container {
   int tag;
 };
 
+struct VecHolder {
+  std::vector<NoCopy> items;
+};
+
 static void bump(NoCopy *p) { p->v++; }
 static void bump_ref(Immovable &r) { r.v++; }
 
@@ -71,5 +76,9 @@ int main() {
   Container c{NoCopy(6), 7};
   Container d(std::move(c));
   assert(d.inner.v == 6 && d.tag == 7 && c.inner.v == 0);
+
+  VecHolder h;
+  VecHolder h2(std::move(h));
+  assert(h2.items.size() == 0);
   return 0;
 }