bpo-42431: Fix outdated bytes comments (GH-23458)

Also move definitions of internal macros F_LJUST etc to private header.

Author: serhiy-storchaka

Include/bytesobject.h

@@ -1,5 +1,5 @@
 
-/* Bytes (String) object interface */
+/* Bytes object interface */
 
 #ifndef Py_BYTESOBJECT_H
 #define Py_BYTESOBJECT_H
@@ -10,23 +10,20 @@ extern "C" {
 #include <stdarg.h>
 
 /*
-Type PyBytesObject represents a character string.  An extra zero byte is
+Type PyBytesObject represents a byte string.  An extra zero byte is
 reserved at the end to ensure it is zero-terminated, but a size is
 present so strings with null bytes in them can be represented.  This
 is an immutable object type.
 
-There are functions to create new string objects, to test
-an object for string-ness, and to get the
-string value.  The latter function returns a null pointer
+There are functions to create new bytes objects, to test
+an object for bytes-ness, and to get the
+byte string value.  The latter function returns a null pointer
 if the object is not of the proper type.
 There is a variant that takes an explicit size as well as a
 variant that assumes a zero-terminated string.  Note that none of the
-functions should be applied to nil objects.
+functions should be applied to NULL pointer.
 */
 
-/* Caching the hash (ob_shash) saves recalculation of a string's hash value.
-   This significantly speeds up dict lookups. */
-
 PyAPI_DATA(PyTypeObject) PyBytes_Type;
 PyAPI_DATA(PyTypeObject) PyBytesIter_Type;
 
@@ -50,26 +47,16 @@ PyAPI_FUNC(PyObject *) PyBytes_DecodeEscape(const char *, Py_ssize_t,
                                             const char *, Py_ssize_t,
                                             const char *);
 
-/* Provides access to the internal data buffer and size of a string
-   object or the default encoded version of a Unicode object. Passing
-   NULL as *len parameter will force the string buffer to be
-   0-terminated (passing a string with embedded NULL characters will
+/* Provides access to the internal data buffer and size of a bytes object.
+   Passing NULL as len parameter will force the string buffer to be
+   0-terminated (passing a string with embedded NUL characters will
    cause an exception).  */
 PyAPI_FUNC(int) PyBytes_AsStringAndSize(
-    PyObject *obj,      /* string or Unicode object */
+    PyObject *obj,      /* bytes object */
     char **s,           /* pointer to buffer variable */
-    Py_ssize_t *len     /* pointer to length variable or NULL
-                           (only possible for 0-terminated
-                           strings) */
+    Py_ssize_t *len     /* pointer to length variable or NULL */
     );
 
-/* Flags used by string formatting */
-#define F_LJUST (1<<0)
-#define F_SIGN  (1<<1)
-#define F_BLANK (1<<2)
-#define F_ALT   (1<<3)
-#define F_ZERO  (1<<4)
-
 #ifndef Py_LIMITED_API
 #  define Py_CPYTHON_BYTESOBJECT_H
 #  include  "cpython/bytesobject.h"

Include/cpython/bytesobject.h

@@ -10,7 +10,7 @@ typedef struct {
     /* Invariants:
      *     ob_sval contains space for 'ob_size+1' elements.
      *     ob_sval[ob_size] == 0.
-     *     ob_shash is the hash of the string or -1 if not computed yet.
+     *     ob_shash is the hash of the byte string or -1 if not computed yet.
      */
 } PyBytesObject;
 

Include/internal/pycore_format.h

@@ -0,0 +1,27 @@
+#ifndef Py_INTERNAL_FORMAT_H
+#define Py_INTERNAL_FORMAT_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef Py_BUILD_CORE
+#  error "this header requires Py_BUILD_CORE define"
+#endif
+
+/* Format codes
+ * F_LJUST      '-'
+ * F_SIGN       '+'
+ * F_BLANK      ' '
+ * F_ALT        '#'
+ * F_ZERO       '0'
+ */
+#define F_LJUST (1<<0)
+#define F_SIGN  (1<<1)
+#define F_BLANK (1<<2)
+#define F_ALT   (1<<3)
+#define F_ZERO  (1<<4)
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_INTERNAL_FORMAT_H */

Makefile.pre.in

@@ -1112,6 +1112,7 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/internal/pycore_context.h \
 		$(srcdir)/Include/internal/pycore_dtoa.h \
 		$(srcdir)/Include/internal/pycore_fileutils.h \
+		$(srcdir)/Include/internal/pycore_format.h \
 		$(srcdir)/Include/internal/pycore_getopt.h \
 		$(srcdir)/Include/internal/pycore_gil.h \
 		$(srcdir)/Include/internal/pycore_hamt.h \

Objects/bytearrayobject.c

@@ -13,10 +13,9 @@ class bytearray "PyByteArrayObject *" "&PyByteArray_Type"
 [clinic start generated code]*/
 /*[clinic end generated code: output=da39a3ee5e6b4b0d input=5535b77c37a119e0]*/
 
+/* For PyByteArray_AS_STRING(). */
 char _PyByteArray_empty_string[] = "";
 
-/* end nullbytes support */
-
 /* Helpers */
 
 static int
@@ -266,7 +265,7 @@ PyByteArray_Concat(PyObject *a, PyObject *b)
 
     result = (PyByteArrayObject *) \
         PyByteArray_FromStringAndSize(NULL, va.len + vb.len);
-    // result->ob_bytes is NULL if result is an empty string:
+    // result->ob_bytes is NULL if result is an empty bytearray:
     // if va.len + vb.len equals zero.
     if (result != NULL && result->ob_bytes != NULL) {
         memcpy(result->ob_bytes, va.buf, va.len);
@@ -1007,9 +1006,6 @@ bytearray_richcompare(PyObject *self, PyObject *other, int op)
     Py_buffer self_bytes, other_bytes;
     int cmp;
 
-    /* Bytes can be compared to anything that supports the (binary)
-       buffer API.  Except that a comparison with Unicode is always an
-       error, even if the comparison is for equality. */
     if (!PyObject_CheckBuffer(self) || !PyObject_CheckBuffer(other)) {
         if (PyUnicode_Check(self) || PyUnicode_Check(other)) {
             if (_Py_GetConfig()->bytes_warning && (op == Py_EQ || op == Py_NE)) {
@@ -1021,6 +1017,7 @@ bytearray_richcompare(PyObject *self, PyObject *other, int op)
         Py_RETURN_NOTIMPLEMENTED;
     }
 
+    /* Bytearrays can be compared to anything that supports the buffer API. */
     if (PyObject_GetBuffer(self, &self_bytes, PyBUF_SIMPLE) != 0) {
         PyErr_Clear();
         Py_RETURN_NOTIMPLEMENTED;
@@ -1328,7 +1325,7 @@ bytearray_translate_impl(PyByteArrayObject *self, PyObject *table,
         if (trans_table[c] != -1)
             *output++ = (char)trans_table[c];
     }
-    /* Fix the size of the resulting string */
+    /* Fix the size of the resulting bytearray */
     if (inlen > 0)
         if (PyByteArray_Resize(result, output - output_start) < 0) {
             Py_CLEAR(result);
@@ -2083,7 +2080,7 @@ bytearray.hex
         How many bytes between separators.  Positive values count from the
         right, negative values count from the left.
 
-Create a str of hexadecimal numbers from a bytearray object.
+Create a string of hexadecimal numbers from a bytearray object.
 
 Example:
 >>> value = bytearray([0xb9, 0x01, 0xef])
@@ -2099,7 +2096,7 @@ Create a str of hexadecimal numbers from a bytearray object.
 
 static PyObject *
 bytearray_hex_impl(PyByteArrayObject *self, PyObject *sep, int bytes_per_sep)
-/*[clinic end generated code: output=29c4e5ef72c565a0 input=814c15830ac8c4b5]*/
+/*[clinic end generated code: output=29c4e5ef72c565a0 input=808667e49bcccb54]*/
 {
     char* argbuf = PyByteArray_AS_STRING(self);
     Py_ssize_t arglen = PyByteArray_GET_SIZE(self);
@@ -2358,7 +2355,7 @@ PyTypeObject PyByteArray_Type = {
     PyObject_Del,                       /* tp_free */
 };
 
-/*********************** Bytes Iterator ****************************/
+/*********************** Bytearray Iterator ****************************/
 
 typedef struct {
     PyObject_HEAD

Objects/bytesobject.c

@@ -5,6 +5,7 @@
 #include "Python.h"
 #include "pycore_abstract.h"      // _PyIndex_Check()
 #include "pycore_bytes_methods.h" // _Py_bytes_startswith()
+#include "pycore_format.h"        // F_LJUST
 #include "pycore_initconfig.h"    // _PyStatus_OK()
 #include "pycore_object.h"        // _PyObject_GC_TRACK
 #include "pycore_pymem.h"         // PYMEM_CLEANBYTE
@@ -21,11 +22,11 @@ class bytes "PyBytesObject *" "&PyBytes_Type"
 
 _Py_IDENTIFIER(__bytes__);
 
-/* PyBytesObject_SIZE gives the basic size of a string; any memory allocation
-   for a string of length n should request PyBytesObject_SIZE + n bytes.
+/* PyBytesObject_SIZE gives the basic size of a bytes object; any memory allocation
+   for a bytes object of length n should request PyBytesObject_SIZE + n bytes.
 
    Using PyBytesObject_SIZE instead of sizeof(PyBytesObject) saves
-   3 bytes per string allocation on a typical system.
+   3 or 7 bytes per bytes object allocation on a typical system.
 */
 #define PyBytesObject_SIZE (offsetof(PyBytesObject, ob_sval) + 1)
 
@@ -439,19 +440,6 @@ getnextarg(PyObject *args, Py_ssize_t arglen, Py_ssize_t *p_argidx)
     return NULL;
 }
 
-/* Format codes
- * F_LJUST      '-'
- * F_SIGN       '+'
- * F_BLANK      ' '
- * F_ALT        '#'
- * F_ZERO       '0'
- */
-#define F_LJUST (1<<0)
-#define F_SIGN  (1<<1)
-#define F_BLANK (1<<2)
-#define F_ALT   (1<<3)
-#define F_ZERO  (1<<4)
-
 /* Returns a new reference to a PyBytes object, or NULL on failure. */
 
 static char*
@@ -1560,7 +1548,7 @@ bytes_richcompare(PyBytesObject *a, PyBytesObject *b, int op)
         case Py_EQ:
         case Py_LE:
         case Py_GE:
-            /* a string is equal to itself */
+            /* a byte string is equal to itself */
             Py_RETURN_TRUE;
         case Py_NE:
         case Py_LT:
@@ -2149,7 +2137,7 @@ bytes_translate_impl(PyBytesObject *self, PyObject *table,
         Py_INCREF(input_obj);
         return input_obj;
     }
-    /* Fix the size of the resulting string */
+    /* Fix the size of the resulting byte string */
     if (inlen > 0)
         _PyBytes_Resize(&result, output - output_start);
     return result;
@@ -2453,7 +2441,7 @@ bytes.hex
         How many bytes between separators.  Positive values count from the
         right, negative values count from the left.
 
-Create a str of hexadecimal numbers from a bytes object.
+Create a string of hexadecimal numbers from a bytes object.
 
 Example:
 >>> value = b'\xb9\x01\xef'
@@ -2469,7 +2457,7 @@ Create a str of hexadecimal numbers from a bytes object.
 
 static PyObject *
 bytes_hex_impl(PyBytesObject *self, PyObject *sep, int bytes_per_sep)
-/*[clinic end generated code: output=1f134da504064139 input=f1238d3455990218]*/
+/*[clinic end generated code: output=1f134da504064139 input=1a21282b1f1ae595]*/
 {
     const char *argbuf = PyBytes_AS_STRING(self);
     Py_ssize_t arglen = PyBytes_GET_SIZE(self);
@@ -2771,7 +2759,7 @@ _PyBytes_FromIterator(PyObject *it, PyObject *x)
     Py_ssize_t i, size;
     _PyBytesWriter writer;
 
-    /* For iterator version, create a string object and resize as needed */
+    /* For iterator version, create a bytes object and resize as needed */
     size = PyObject_LengthHint(x, 64);
     if (size == -1 && PyErr_Occurred())
         return NULL;

Objects/clinic/bytearrayobject.c.h

@@ -42,6 +42,7 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include "Python.h"
 #include "pycore_abstract.h"      // _PyIndex_Check()
 #include "pycore_bytes_methods.h" // _Py_bytes_lower()
+#include "pycore_format.h"        // F_LJUST
 #include "pycore_initconfig.h"    // _PyStatus_OK()
 #include "pycore_interp.h"        // PyInterpreterState.fs_codec
 #include "pycore_object.h"        // _PyObject_GC_TRACK()

Objects/clinic/bytesobject.c.h

@@ -176,6 +176,7 @@
     <ClInclude Include="..\Include\internal\pycore_context.h" />
     <ClInclude Include="..\Include\internal\pycore_dtoa.h" />
     <ClInclude Include="..\Include\internal\pycore_fileutils.h" />
+    <ClInclude Include="..\Include\internal\pycore_format.h" />
     <ClInclude Include="..\Include\internal\pycore_gc.h" />
     <ClInclude Include="..\Include\internal\pycore_getopt.h" />
     <ClInclude Include="..\Include\internal\pycore_gil.h" />