Merge pull request gcc-mirror#84 from villevoutilainen/exception-leak-found-by-ran

Fix the exception leak found by Ran

Author: villevoutilainen

gcc/cp/contracts.cc

@@ -1543,7 +1543,13 @@ build_contract_condition_function (tree fndecl, bool pre)
   *last = void_list_node;
 
   /* The handlers are void fns.  */
-  TREE_TYPE (fn) = build_function_type (void_type_node, arg_types);
+  tree adjusted_type = build_function_type (void_type_node, arg_types);
+
+  /* If the original function is noexcept, build a noexcept function. */
+  if (flag_exceptions && type_noexcept_p (TREE_TYPE (fndecl)))
+    adjusted_type = build_exception_variant (adjusted_type, noexcept_true_spec);
+
+  TREE_TYPE (fn) = adjusted_type;
   DECL_RESULT (fn) = NULL_TREE; /* Let the start function code fill it in.  */
 
   if (DECL_IOBJ_MEMBER_FUNCTION_P (fndecl))

gcc/testsuite/g++.dg/contracts/cpp26/contract-violation-noexcept2.C

@@ -0,0 +1,38 @@
+// test that a noexcept function can't throw even if a violation handler throws
+// { dg-do run }
+// { dg-options "-std=c++2a -fcontracts  -fcontracts-nonattr " }
+// { dg-additional-sources "throwing-violation-handler.cc" }
+
+#include <exception>
+
+void f(int x) noexcept pre(x >= 0)
+{
+}
+
+void g();
+
+bool f_result = true;
+
+void my_term()
+{
+  try { throw; }
+  catch(int) { __builtin_exit(0); }
+}
+
+
+int main()
+{
+  std::set_terminate (my_term);
+  try
+  {
+    g();
+  } catch (...) {
+    // We should not get here
+    __builtin_abort();
+  }
+  if (!f_result)
+    // We should not get here
+    __builtin_abort();
+  // We should not get here
+  __builtin_abort();
+}

gcc/testsuite/g++.dg/contracts/cpp26/throwing-violation-handler.cc

@@ -0,0 +1,23 @@
+#include <contracts>
+
+void handle_contract_violation(const std::contracts::contract_violation&)
+{
+  throw 666;
+}
+
+/* ODR hack to the hilt - f is actually noexcept, and has a contract.
+   We do this to avoid the call site knowing that, so that we verify
+   that the function terminates when it calls the throwing handler
+   that we use above. */
+int f(int);
+
+extern bool f_result;
+
+void g()
+{
+  try {
+    f(-42);
+  } catch (...) {
+    f_result = false;
+  }
+}