updated pybind11 to support python 3.9

Author: Gal Ben David

README.md

@@ -8,7 +8,7 @@
 </p>
 
 ![license](https://img.shields.io/badge/MIT-License-blue)
-![Python](https://img.shields.io/badge/Python-3.6%20%7C%203.7%20%7C%203.8%20%7C%20pypy3-blue)
+![Python](https://img.shields.io/badge/Python-3.6%20%7C%203.7%20%7C%203.8%20%7C%203.9%20%7C%20pypy3-blue)
 ![Build](https://github.com/Intsights/PySubstringSearch/workflows/Build/badge.svg)
 [![PyPi](https://img.shields.io/pypi/v/PySubstringSearch.svg)](https://pypi.org/project/PySubstringSearch/)
 

src/pybind11/attr.h

@@ -12,7 +12,7 @@
 
 #include "cast.h"
 
-NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 
 /// \addtogroup annotations
 /// @{
@@ -23,6 +23,9 @@ struct is_method { handle class_; is_method(const handle &c) : class_(c) { } };
 /// Annotation for operators
 struct is_operator { };
 
+/// Annotation for classes that cannot be subclassed
+struct is_final { };
+
 /// Annotation for parent scope
 struct scope { handle value; scope(const handle &s) : value(s) { } };
 
@@ -37,8 +40,9 @@ struct sibling { handle value; sibling(const handle &value) : value(value.ptr())
 
 /// Annotation indicating that a class derives from another given type
 template <typename T> struct base {
+
     PYBIND11_DEPRECATED("base<T>() was deprecated in favor of specifying 'T' as a template argument to class_")
-    base() { }
+    base() { } // NOLINT(modernize-use-equals-default): breaks MSVC 2015 when adding an attribute
 };
 
 /// Keep patient alive while nurse lives
@@ -58,7 +62,7 @@ struct metaclass {
     handle value;
 
     PYBIND11_DEPRECATED("py::metaclass() is no longer required. It's turned on by default now.")
-    metaclass() {}
+    metaclass() { } // NOLINT(modernize-use-equals-default): breaks MSVC 2015 when adding an attribute
 
     /// Override pybind11's default metaclass
     explicit metaclass(handle value) : value(value) { }
@@ -70,6 +74,9 @@ struct module_local { const bool value; constexpr module_local(bool v = true) :
 /// Annotation to mark enums as an arithmetic type
 struct arithmetic { };
 
+/// Mark a function for addition at the beginning of the existing overload chain instead of the end
+struct prepend { };
+
 /** \rst
     A call policy which places one or more guard variables (``Ts...``) around the function call.
 
@@ -110,7 +117,7 @@ struct call_guard<T, Ts...> {
 
 /// @} annotations
 
-NAMESPACE_BEGIN(detail)
+PYBIND11_NAMESPACE_BEGIN(detail)
 /* Forward declarations */
 enum op_id : int;
 enum op_type : int;
@@ -134,7 +141,8 @@ struct argument_record {
 struct function_record {
     function_record()
         : is_constructor(false), is_new_style_constructor(false), is_stateless(false),
-          is_operator(false), has_args(false), has_kwargs(false), is_method(false) { }
+          is_operator(false), is_method(false), has_args(false),
+          has_kwargs(false), has_kw_only_args(false), prepend(false) { }
 
     /// Function name
     char *name = nullptr; /* why no C++ strings? They generate heavier code.. */
@@ -172,18 +180,30 @@ struct function_record {
     /// True if this is an operator (__add__), etc.
     bool is_operator : 1;
 
+    /// True if this is a method
+    bool is_method : 1;
+
     /// True if the function has a '*args' argument
     bool has_args : 1;
 
     /// True if the function has a '**kwargs' argument
     bool has_kwargs : 1;
 
-    /// True if this is a method
-    bool is_method : 1;
+    /// True once a 'py::kw_only' is encountered (any following args are keyword-only)
+    bool has_kw_only_args : 1;
+
+    /// True if this function is to be inserted at the beginning of the overload resolution chain
+    bool prepend : 1;
 
     /// Number of arguments (including py::args and/or py::kwargs, if present)
     std::uint16_t nargs;
 
+    /// Number of trailing arguments (counted in `nargs`) that are keyword-only
+    std::uint16_t nargs_kw_only = 0;
+
+    /// Number of leading arguments (counted in `nargs`) that are positional-only
+    std::uint16_t nargs_pos_only = 0;
+
     /// Python method object
     PyMethodDef *def = nullptr;
 
@@ -201,7 +221,7 @@ struct function_record {
 struct type_record {
     PYBIND11_NOINLINE type_record()
         : multiple_inheritance(false), dynamic_attr(false), buffer_protocol(false),
-          default_holder(true), module_local(false) { }
+          default_holder(true), module_local(false), is_final(false) { }
 
     /// Handle to the parent scope
     handle scope;
@@ -254,6 +274,9 @@ struct type_record {
     /// Is the class definition local to the module shared object?
     bool module_local : 1;
 
+    /// Is the class inheritable from python classes?
+    bool is_final : 1;
+
     PYBIND11_NOINLINE void add_base(const std::type_info &base, void *(*caster)(void *)) {
         auto base_info = detail::get_type_info(base, false);
         if (!base_info) {
@@ -353,12 +376,20 @@ template <> struct process_attribute<is_new_style_constructor> : process_attribu
     static void init(const is_new_style_constructor &, function_record *r) { r->is_new_style_constructor = true; }
 };
 
+inline void process_kw_only_arg(const arg &a, function_record *r) {
+    if (!a.name || strlen(a.name) == 0)
+        pybind11_fail("arg(): cannot specify an unnamed argument after an kw_only() annotation");
+    ++r->nargs_kw_only;
+}
+
 /// Process a keyword argument attribute (*without* a default value)
 template <> struct process_attribute<arg> : process_attribute_default<arg> {
     static void init(const arg &a, function_record *r) {
         if (r->is_method && r->args.empty())
             r->args.emplace_back("self", nullptr, handle(), true /*convert*/, false /*none not allowed*/);
         r->args.emplace_back(a.name, nullptr, handle(), !a.flag_noconvert, a.flag_none);
+
+        if (r->has_kw_only_args) process_kw_only_arg(a, r);
     }
 };
 
@@ -390,6 +421,22 @@ template <> struct process_attribute<arg_v> : process_attribute_default<arg_v> {
 #endif
         }
         r->args.emplace_back(a.name, a.descr, a.value.inc_ref(), !a.flag_noconvert, a.flag_none);
+
+        if (r->has_kw_only_args) process_kw_only_arg(a, r);
+    }
+};
+
+/// Process a keyword-only-arguments-follow pseudo argument
+template <> struct process_attribute<kw_only> : process_attribute_default<kw_only> {
+    static void init(const kw_only &, function_record *r) {
+        r->has_kw_only_args = true;
+    }
+};
+
+/// Process a positional-only-argument maker
+template <> struct process_attribute<pos_only> : process_attribute_default<pos_only> {
+    static void init(const pos_only &, function_record *r) {
+        r->nargs_pos_only = static_cast<std::uint16_t>(r->args.size());
     }
 };
 
@@ -416,6 +463,11 @@ struct process_attribute<dynamic_attr> : process_attribute_default<dynamic_attr>
     static void init(const dynamic_attr &, type_record *r) { r->dynamic_attr = true; }
 };
 
+template <>
+struct process_attribute<is_final> : process_attribute_default<is_final> {
+    static void init(const is_final &, type_record *r) { r->is_final = true; }
+};
+
 template <>
 struct process_attribute<buffer_protocol> : process_attribute_default<buffer_protocol> {
     static void init(const buffer_protocol &, type_record *r) { r->buffer_protocol = true; }
@@ -431,6 +483,12 @@ struct process_attribute<module_local> : process_attribute_default<module_local>
     static void init(const module_local &l, type_record *r) { r->module_local = l.value; }
 };
 
+/// Process a 'prepend' attribute, putting this at the beginning of the overload chain
+template <>
+struct process_attribute<prepend> : process_attribute_default<prepend> {
+    static void init(const prepend &, function_record *r) { r->prepend = true; }
+};
+
 /// Process an 'arithmetic' attribute for enums (does nothing here)
 template <>
 struct process_attribute<arithmetic> : process_attribute_default<arithmetic> {};
@@ -489,5 +547,5 @@ constexpr bool expected_num_args(size_t nargs, bool has_args, bool has_kwargs) {
     return named == 0 || (self + named + has_args + has_kwargs) == nargs;
 }
 
-NAMESPACE_END(detail)
-NAMESPACE_END(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

src/pybind11/buffer_info.h

@@ -11,7 +11,30 @@
 
 #include "detail/common.h"
 
-NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+// Default, C-style strides
+inline std::vector<ssize_t> c_strides(const std::vector<ssize_t> &shape, ssize_t itemsize) {
+    auto ndim = shape.size();
+    std::vector<ssize_t> strides(ndim, itemsize);
+    if (ndim > 0)
+        for (size_t i = ndim - 1; i > 0; --i)
+            strides[i - 1] = strides[i] * shape[i];
+    return strides;
+}
+
+// F-style strides; default when constructing an array_t with `ExtraFlags & f_style`
+inline std::vector<ssize_t> f_strides(const std::vector<ssize_t> &shape, ssize_t itemsize) {
+    auto ndim = shape.size();
+    std::vector<ssize_t> strides(ndim, itemsize);
+    for (size_t i = 1; i < ndim; ++i)
+        strides[i] = strides[i - 1] * shape[i - 1];
+    return strides;
+}
+
+PYBIND11_NAMESPACE_END(detail)
 
 /// Information record describing a Python buffer object
 struct buffer_info {
@@ -24,7 +47,7 @@ struct buffer_info {
     std::vector<ssize_t> strides; // Number of bytes between adjacent entries (for each per dimension)
     bool readonly = false;        // flag to indicate if the underlying storage may be written to
 
-    buffer_info() { }
+    buffer_info() = default;
 
     buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,
                 detail::any_container<ssize_t> shape_in, detail::any_container<ssize_t> strides_in, bool readonly=false)
@@ -53,8 +76,15 @@ struct buffer_info {
 
     explicit buffer_info(Py_buffer *view, bool ownview = true)
     : buffer_info(view->buf, view->itemsize, view->format, view->ndim,
-            {view->shape, view->shape + view->ndim}, {view->strides, view->strides + view->ndim}, view->readonly) {
-        this->view = view;
+            {view->shape, view->shape + view->ndim},
+            /* Though buffer::request() requests PyBUF_STRIDES, ctypes objects
+             * ignore this flag and return a view with NULL strides.
+             * When strides are NULL, build them manually.  */
+            view->strides
+            ? std::vector<ssize_t>(view->strides, view->strides + view->ndim)
+            : detail::c_strides({view->shape, view->shape + view->ndim}, view->itemsize),
+            view->readonly) {
+        this->m_view = view;
         this->ownview = ownview;
     }
 
@@ -73,28 +103,30 @@ struct buffer_info {
         ndim = rhs.ndim;
         shape = std::move(rhs.shape);
         strides = std::move(rhs.strides);
-        std::swap(view, rhs.view);
+        std::swap(m_view, rhs.m_view);
         std::swap(ownview, rhs.ownview);
         readonly = rhs.readonly;
         return *this;
     }
 
     ~buffer_info() {
-        if (view && ownview) { PyBuffer_Release(view); delete view; }
+        if (m_view && ownview) { PyBuffer_Release(m_view); delete m_view; }
     }
 
+    Py_buffer *view() const { return m_view; }
+    Py_buffer *&view() { return m_view; }
 private:
     struct private_ctr_tag { };
 
     buffer_info(private_ctr_tag, void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,
                 detail::any_container<ssize_t> &&shape_in, detail::any_container<ssize_t> &&strides_in, bool readonly)
     : buffer_info(ptr, itemsize, format, ndim, std::move(shape_in), std::move(strides_in), readonly) { }
 
-    Py_buffer *view = nullptr;
+    Py_buffer *m_view = nullptr;
     bool ownview = false;
 };
 
-NAMESPACE_BEGIN(detail)
+PYBIND11_NAMESPACE_BEGIN(detail)
 
 template <typename T, typename SFINAE = void> struct compare_buffer_info {
     static bool compare(const buffer_info& b) {
@@ -110,5 +142,5 @@ template <typename T> struct compare_buffer_info<T, detail::enable_if_t<std::is_
     }
 };
 
-NAMESPACE_END(detail)
-NAMESPACE_END(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)