Merge branch 'pybind:master' into master

include/pybind11/attr.h

@@ -10,6 +10,7 @@
 
 #pragma once
 
+#include "detail/common.h"
 #include "cast.h"
 
 #include <functional>
@@ -477,7 +478,7 @@ struct process_attribute<arg_v> : process_attribute_default<arg_v> {
         }
 
         if (!a.value) {
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             std::string descr("'");
             if (a.name) {
                 descr += std::string(a.name) + ": ";
@@ -498,7 +499,8 @@ struct process_attribute<arg_v> : process_attribute_default<arg_v> {
 #else
             pybind11_fail("arg(): could not convert default argument "
                           "into a Python object (type not registered yet?). "
-                          "Compile in debug mode for more information.");
+                          "#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for "
+                          "more information.");
 #endif
         }
         r->args.emplace_back(a.name, a.descr, a.value.inc_ref(), !a.flag_noconvert, a.flag_none);

include/pybind11/cast.h

@@ -777,8 +777,9 @@ protected:
             return true;
         }
         throw cast_error("Unable to cast from non-held to held instance (T& to Holder<T>) "
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-                         "(compile in debug mode for type information)");
+                         "(#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for "
+                         "type information)");
 #else
                          "of type '"
                          + type_id<holder_type>() + "''");
@@ -1001,9 +1002,9 @@ struct return_value_policy_override<
 template <typename T, typename SFINAE>
 type_caster<T, SFINAE> &load_type(type_caster<T, SFINAE> &conv, const handle &handle) {
     if (!conv.load(handle, true)) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-        throw cast_error(
+        throw cast_error("Unable to cast Python instance to C++ type (#define "
-            "Unable to cast Python instance to C++ type (compile in debug mode for details)");
+                         "PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)");
 #else
         throw cast_error("Unable to cast Python instance of type "
                          + (std::string) str(type::handle_of(handle)) + " to C++ type '"
@@ -1068,10 +1069,10 @@ inline void handle::cast() const {
 template <typename T>
 detail::enable_if_t<!detail::move_never<T>::value, T> move(object &&obj) {
     if (obj.ref_count() > 1) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
         throw cast_error(
             "Unable to cast Python instance to C++ rvalue: instance has multiple references"
-            " (compile in debug mode for details)");
+            " (#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)");
 #else
         throw cast_error("Unable to move from Python " + (std::string) str(type::handle_of(obj))
                          + " instance to C++ " + type_id<T>()
@@ -1172,10 +1173,10 @@ PYBIND11_NAMESPACE_END(detail)
 
 // The overloads could coexist, i.e. the #if is not strictly speaking needed,
 // but it is an easy minor optimization.
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
 inline cast_error cast_error_unable_to_convert_call_arg() {
-    return cast_error(
+    return cast_error("Unable to convert call argument to Python object (#define "
-        "Unable to convert call argument to Python object (compile in debug mode for details)");
+                      "PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)");
 }
 #else
 inline cast_error cast_error_unable_to_convert_call_arg(const std::string &name,
@@ -1197,7 +1198,7 @@ tuple make_tuple(Args &&...args_) {
         detail::make_caster<Args>::cast(std::forward<Args>(args_), policy, nullptr))...}};
     for (size_t i = 0; i < args.size(); i++) {
         if (!args[i]) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             throw cast_error_unable_to_convert_call_arg();
 #else
             std::array<std::string, size> argtypes{{type_id<Args>()...}};
@@ -1249,7 +1250,7 @@ private:
         : arg(base), value(reinterpret_steal<object>(detail::make_caster<T>::cast(
                          std::forward<T>(x), return_value_policy::automatic, {}))),
           descr(descr)
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
           ,
           type(type_id<T>())
 #endif
@@ -1289,7 +1290,7 @@ public:
     object value;
     /// The (optional) description of the default value
     const char *descr;
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
     /// The C++ type name of the default value (only available when compiled in debug mode)
     std::string type;
 #endif
@@ -1487,7 +1488,7 @@ private:
         auto o = reinterpret_steal<object>(
             detail::make_caster<T>::cast(std::forward<T>(x), policy, {}));
         if (!o) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             throw cast_error_unable_to_convert_call_arg();
 #else
             throw cast_error_unable_to_convert_call_arg(std::to_string(args_list.size()),
@@ -1505,21 +1506,21 @@ private:
 
     void process(list & /*args_list*/, arg_v a) {
         if (!a.name) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             nameless_argument_error();
 #else
             nameless_argument_error(a.type);
 #endif
         }
         if (m_kwargs.contains(a.name)) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             multiple_values_error();
 #else
             multiple_values_error(a.name);
 #endif
         }
         if (!a.value) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             throw cast_error_unable_to_convert_call_arg();
 #else
             throw cast_error_unable_to_convert_call_arg(a.name, a.type);
@@ -1534,7 +1535,7 @@ private:
         }
         for (auto k : reinterpret_borrow<dict>(kp)) {
             if (m_kwargs.contains(k.first)) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
                 multiple_values_error();
 #else
                 multiple_values_error(str(k.first));
@@ -1545,9 +1546,10 @@ private:
     }
 
     [[noreturn]] static void nameless_argument_error() {
-        throw type_error("Got kwargs without a name; only named arguments "
+        throw type_error(
-                         "may be passed via py::arg() to a python function call. "
+            "Got kwargs without a name; only named arguments "
-                         "(compile in debug mode for details)");
+            "may be passed via py::arg() to a python function call. "
+            "(#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)");
     }
     [[noreturn]] static void nameless_argument_error(const std::string &type) {
         throw type_error("Got kwargs without a name of type '" + type
@@ -1555,8 +1557,9 @@ private:
                            "arguments may be passed via py::arg() to a python function call. ");
     }
     [[noreturn]] static void multiple_values_error() {
-        throw type_error("Got multiple values for keyword argument "
+        throw type_error(
-                         "(compile in debug mode for details)");
+            "Got multiple values for keyword argument "
+            "(#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)");
     }
 
     [[noreturn]] static void multiple_values_error(const std::string &name) {
@@ -1603,7 +1606,7 @@ unpacking_collector<policy> collect_arguments(Args &&...args) {
 template <typename Derived>
 template <return_value_policy policy, typename... Args>
 object object_api<Derived>::operator()(Args &&...args) const {
-#ifndef NDEBUG
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
     if (!PyGILState_Check()) {
         pybind11_fail("pybind11::object_api<>::operator() PyGILState_Check() failure.");
     }

include/pybind11/detail/common.h

@@ -1157,5 +1157,12 @@ constexpr inline bool silence_msvc_c4127(bool cond) { return cond; }
 #    define PYBIND11_SILENCE_MSVC_C4127(...) __VA_ARGS__
 #endif
 
+// Pybind offers detailed error messages by default for all builts that are debug (through the
+// negation of ndebug). This can also be manually enabled by users, for any builds, through
+// defining PYBIND11_DETAILED_ERROR_MESSAGES.
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES) && !defined(NDEBUG)
+#    define PYBIND11_DETAILED_ERROR_MESSAGES
+#endif
+
 PYBIND11_NAMESPACE_END(detail)
 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

include/pybind11/detail/type_caster_base.h

@@ -394,15 +394,16 @@ instance::get_value_and_holder(const type_info *find_type /*= nullptr default in
         return value_and_holder();
     }
 
-#if defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-    pybind11_fail("pybind11::detail::instance::get_value_and_holder: "
-                  "type is not a pybind11 base of the given instance "
-                  "(compile in debug mode for type details)");
-#else
     pybind11_fail("pybind11::detail::instance::get_value_and_holder: `"
                   + get_fully_qualified_tp_name(find_type->type)
                   + "' is not a pybind11 base of the given `"
                   + get_fully_qualified_tp_name(Py_TYPE(this)) + "' instance");
+#else
+    pybind11_fail(
+        "pybind11::detail::instance::get_value_and_holder: "
+        "type is not a pybind11 base of the given instance "
+        "(#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for type details)");
 #endif
 }
 
@@ -612,14 +613,15 @@ public:
                 if (copy_constructor) {
                     valueptr = copy_constructor(src);
                 } else {
-#if defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-                    throw cast_error("return_value_policy = copy, but type is "
-                                     "non-copyable! (compile in debug mode for details)");
-#else
                     std::string type_name(tinfo->cpptype->name());
                     detail::clean_type_id(type_name);
                     throw cast_error("return_value_policy = copy, but type " + type_name
                                      + " is non-copyable!");
+#else
+                    throw cast_error("return_value_policy = copy, but type is "
+                                     "non-copyable! (#define PYBIND11_DETAILED_ERROR_MESSAGES or "
+                                     "compile in debug mode for details)");
 #endif
                 }
                 wrapper->owned = true;
@@ -631,15 +633,16 @@ public:
                 } else if (copy_constructor) {
                     valueptr = copy_constructor(src);
                 } else {
-#if defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-                    throw cast_error("return_value_policy = move, but type is neither "
-                                     "movable nor copyable! "
-                                     "(compile in debug mode for details)");
-#else
                     std::string type_name(tinfo->cpptype->name());
                     detail::clean_type_id(type_name);
                     throw cast_error("return_value_policy = move, but type " + type_name
                                      + " is neither movable nor copyable!");
+#else
+                    throw cast_error("return_value_policy = move, but type is neither "
+                                     "movable nor copyable! "
+                                     "(#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in "
+                                     "debug mode for details)");
 #endif
                 }
                 wrapper->owned = true;

include/pybind11/gil.h

@@ -62,7 +62,7 @@ public:
 
         if (!tstate) {
             tstate = PyThreadState_New(internals.istate);
-#    if !defined(NDEBUG)
+#    if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             if (!tstate) {
                 pybind11_fail("scoped_acquire: could not create thread state!");
             }
@@ -84,7 +84,7 @@ public:
 
     PYBIND11_NOINLINE void dec_ref() {
         --tstate->gilstate_counter;
-#    if !defined(NDEBUG)
+#    if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
         if (detail::get_thread_state_unchecked() != tstate) {
             pybind11_fail("scoped_acquire::dec_ref(): thread state must be current!");
         }
@@ -93,7 +93,7 @@ public:
         }
 #    endif
         if (tstate->gilstate_counter == 0) {
-#    if !defined(NDEBUG)
+#    if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             if (!release) {
                 pybind11_fail("scoped_acquire::dec_ref(): internal error!");
             }

include/pybind11/pybind11.h

@@ -370,7 +370,7 @@ protected:
         rec->is_constructor = (std::strcmp(rec->name, "__init__") == 0)
                               || (std::strcmp(rec->name, "__setstate__") == 0);
 
-#if !defined(NDEBUG) && !defined(PYBIND11_DISABLE_NEW_STYLE_INIT_WARNING)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES) && !defined(PYBIND11_DISABLE_NEW_STYLE_INIT_WARNING)
         if (rec->is_constructor && !rec->is_new_style_constructor) {
             const auto class_name
                 = detail::get_fully_qualified_tp_name((PyTypeObject *) rec->scope.ptr());
@@ -518,8 +518,9 @@ protected:
             if (chain->is_method != rec->is_method) {
                 pybind11_fail(
                     "overloading a method with both static and instance methods is not supported; "
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-                    "compile in debug mode for more details"
+                    "#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for more "
+                    "details"
 #else
                     "error while attempting to bind "
                     + std::string(rec->is_method ? "instance" : "static") + " method "
@@ -906,7 +907,7 @@ protected:
 
 // 5. Put everything in a vector.  Not technically step 5, we've been building it
 // in `call.args` all along.
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
                 if (call.args.size() != func.nargs || call.args_convert.size() != func.nargs) {
                     pybind11_fail("Internal error: function call dispatcher inserted wrong number "
                                   "of arguments!");

tests/pybind11_tests.cpp

@@ -67,10 +67,10 @@ PYBIND11_MODULE(pybind11_tests, m) {
 
     bind_ConstructorStats(m);
 
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-    m.attr("debug_enabled") = true;
+    m.attr("detailed_error_messages_enabled") = true;
 #else
-    m.attr("debug_enabled") = false;
+    m.attr("detailed_error_messages_enabled") = false;
 #endif
 
     py::class_<UserType>(m, "UserType", "A `py::class_` type for testing")

tests/test_methods_and_attributes.cpp

@@ -361,10 +361,10 @@ TEST_SUBMODULE(methods_and_attributes, m) {
 
     // test_bad_arg_default
     // Issue/PR #648: bad arg default debugging output
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-    m.attr("debug_enabled") = true;
+    m.attr("detailed_error_messages_enabled") = true;
 #else
-    m.attr("debug_enabled") = false;
+    m.attr("detailed_error_messages_enabled") = false;
 #endif
     m.def("bad_arg_def_named", [] {
         auto m = py::module_::import("pybind11_tests");

tests/test_methods_and_attributes.py

@@ -216,15 +216,15 @@ def test_metaclass_override():
 
 
 def test_no_mixed_overloads():
-    from pybind11_tests import debug_enabled
+    from pybind11_tests import detailed_error_messages_enabled
 
     with pytest.raises(RuntimeError) as excinfo:
         m.ExampleMandA.add_mixed_overloads1()
     assert str(
         excinfo.value
     ) == "overloading a method with both static and instance methods is not supported; " + (
-        "compile in debug mode for more details"
+        "#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for more details"
-        if not debug_enabled
+        if not detailed_error_messages_enabled
         else "error while attempting to bind static method ExampleMandA.overload_mixed1"
         "(arg0: float) -> str"
     )
@@ -234,8 +234,8 @@ def test_no_mixed_overloads():
     assert str(
         excinfo.value
     ) == "overloading a method with both static and instance methods is not supported; " + (
-        "compile in debug mode for more details"
+        "#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for more details"
-        if not debug_enabled
+        if not detailed_error_messages_enabled
         else "error while attempting to bind instance method ExampleMandA.overload_mixed2"
         "(self: pybind11_tests.methods_and_attributes.ExampleMandA, arg0: int, arg1: int)"
         " -> str"
@@ -344,16 +344,16 @@ def test_cyclic_gc():
 
 
 def test_bad_arg_default(msg):
-    from pybind11_tests import debug_enabled
+    from pybind11_tests import detailed_error_messages_enabled
 
     with pytest.raises(RuntimeError) as excinfo:
         m.bad_arg_def_named()
     assert msg(excinfo.value) == (
         "arg(): could not convert default argument 'a: UnregisteredType' in function "
         "'should_fail' into a Python object (type not registered yet?)"
-        if debug_enabled
+        if detailed_error_messages_enabled
         else "arg(): could not convert default argument into a Python object (type not registered "
-        "yet?). Compile in debug mode for more information."
+        "yet?). #define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for more information."
     )
 
     with pytest.raises(RuntimeError) as excinfo:
@@ -361,9 +361,9 @@ def test_bad_arg_default(msg):
     assert msg(excinfo.value) == (
         "arg(): could not convert default argument 'UnregisteredType' in function "
         "'should_fail' into a Python object (type not registered yet?)"
-        if debug_enabled
+        if detailed_error_messages_enabled
         else "arg(): could not convert default argument into a Python object (type not registered "
-        "yet?). Compile in debug mode for more information."
+        "yet?). #define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for more information."
     )
 
 

tests/test_pickling.cpp

@@ -61,6 +61,8 @@ void wrap(py::module m) {
 } // namespace exercise_trampoline
 
 TEST_SUBMODULE(pickling, m) {
+    m.def("simple_callable", []() { return 20220426; });
+
     // test_roundtrip
     class Pickleable {
     public:

tests/test_pickling.py

@@ -1,4 +1,5 @@
 import pickle
+import re
 
 import pytest
 
@@ -6,6 +7,20 @@ import env
 from pybind11_tests import pickling as m
 
 
+def test_pickle_simple_callable():
+    assert m.simple_callable() == 20220426
+    if env.PYPY:
+        serialized = pickle.dumps(m.simple_callable)
+        deserialized = pickle.loads(serialized)
+        assert deserialized() == 20220426
+    else:
+        # To document broken behavior: currently it fails universally with
+        # all C Python versions.
+        with pytest.raises(TypeError) as excinfo:
+            pickle.dumps(m.simple_callable)
+        assert re.search("can.*t pickle .*PyCapsule.* object", str(excinfo.value))
+
+
 @pytest.mark.parametrize("cls_name", ["Pickleable", "PickleableNew"])
 def test_roundtrip(cls_name):
     cls = getattr(m, cls_name)

tests/test_pytypes.py

@@ -4,7 +4,7 @@ import sys
 import pytest
 
 import env
-from pybind11_tests import debug_enabled
+from pybind11_tests import detailed_error_messages_enabled
 from pybind11_tests import pytypes as m
 
 
@@ -416,8 +416,8 @@ def test_print(capture):
         m.print_failure()
     assert str(excinfo.value) == "Unable to convert call argument " + (
         "'1' of type 'UnregisteredType' to Python object"
-        if debug_enabled
+        if detailed_error_messages_enabled
-        else "to Python object (compile in debug mode for details)"
+        else "to Python object (#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)"
     )