gh-89653: PEP 670: Convert unicodeobject.h macros to functions (#92648)

Convert the following Unicode macros to static inline functions.

Surrogate functions:

* Py_UNICODE_IS_SURROGATE()
* Py_UNICODE_IS_HIGH_SURROGATE()
* Py_UNICODE_IS_LOW_SURROGATE()
* Py_UNICODE_HIGH_SURROGATE()
* Py_UNICODE_LOW_SURROGATE()
* Py_UNICODE_JOIN_SURROGATES()

"Is" functions:

* Py_UNICODE_ISALNUM()
* Py_UNICODE_ISSPACE()

In the implementation of these functions, the character type is now
well defined to Py_UCS4.

Include/cpython/unicodeobject.h

@@ -15,53 +15,31 @@
 #  define USE_UNICODE_WCHAR_CACHE 1
 #endif /* USE_UNICODE_WCHAR_CACHE */
 
-/* Since splitting on whitespace is an important use case, and
-   whitespace in most situations is solely ASCII whitespace, we
-   optimize for the common case by using a quick look-up table
-   _Py_ascii_whitespace (see below) with an inlined check.
+// Static inline functions to work with surrogates
+static inline int Py_UNICODE_IS_SURROGATE(Py_UCS4 ch) {
+    return (0xD800 <= ch && ch <= 0xDFFF);
+}
+static inline int Py_UNICODE_IS_HIGH_SURROGATE(Py_UCS4 ch) {
+    return (0xD800 <= ch && ch <= 0xDBFF);
+}
+static inline int Py_UNICODE_IS_LOW_SURROGATE(Py_UCS4 ch) {
+    return (0xDC00 <= ch && ch <= 0xDFFF);
+}
 
- */
-#define Py_UNICODE_ISSPACE(ch) \
-    ((Py_UCS4)(ch) < 128U ? _Py_ascii_whitespace[(ch)] : _PyUnicode_IsWhitespace(ch))
+// Join two surrogate characters and return a single Py_UCS4 value.
+static inline Py_UCS4 Py_UNICODE_JOIN_SURROGATES(Py_UCS4 high, Py_UCS4 low)  {
+    return 0x10000 + (((high & 0x03FF) << 10) | (low & 0x03FF));
+}
 
-#define Py_UNICODE_ISLOWER(ch) _PyUnicode_IsLowercase(ch)
-#define Py_UNICODE_ISUPPER(ch) _PyUnicode_IsUppercase(ch)
-#define Py_UNICODE_ISTITLE(ch) _PyUnicode_IsTitlecase(ch)
-#define Py_UNICODE_ISLINEBREAK(ch) _PyUnicode_IsLinebreak(ch)
+// High surrogate = top 10 bits added to D800
+static inline Py_UCS4 Py_UNICODE_HIGH_SURROGATE(Py_UCS4 ch) {
+    return (0xD800 - (0x10000 >> 10) + (ch >> 10));
+}
 
-#define Py_UNICODE_TOLOWER(ch) _PyUnicode_ToLowercase(ch)
-#define Py_UNICODE_TOUPPER(ch) _PyUnicode_ToUppercase(ch)
-#define Py_UNICODE_TOTITLE(ch) _PyUnicode_ToTitlecase(ch)
-
-#define Py_UNICODE_ISDECIMAL(ch) _PyUnicode_IsDecimalDigit(ch)
-#define Py_UNICODE_ISDIGIT(ch) _PyUnicode_IsDigit(ch)
-#define Py_UNICODE_ISNUMERIC(ch) _PyUnicode_IsNumeric(ch)
-#define Py_UNICODE_ISPRINTABLE(ch) _PyUnicode_IsPrintable(ch)
-
-#define Py_UNICODE_TODECIMAL(ch) _PyUnicode_ToDecimalDigit(ch)
-#define Py_UNICODE_TODIGIT(ch) _PyUnicode_ToDigit(ch)
-#define Py_UNICODE_TONUMERIC(ch) _PyUnicode_ToNumeric(ch)
-
-#define Py_UNICODE_ISALPHA(ch) _PyUnicode_IsAlpha(ch)
-
-#define Py_UNICODE_ISALNUM(ch) \
-   (Py_UNICODE_ISALPHA(ch) || \
-    Py_UNICODE_ISDECIMAL(ch) || \
-    Py_UNICODE_ISDIGIT(ch) || \
-    Py_UNICODE_ISNUMERIC(ch))
-
-/* macros to work with surrogates */
-#define Py_UNICODE_IS_SURROGATE(ch) (0xD800 <= (ch) && (ch) <= 0xDFFF)
-#define Py_UNICODE_IS_HIGH_SURROGATE(ch) (0xD800 <= (ch) && (ch) <= 0xDBFF)
-#define Py_UNICODE_IS_LOW_SURROGATE(ch) (0xDC00 <= (ch) && (ch) <= 0xDFFF)
-/* Join two surrogate characters and return a single Py_UCS4 value. */
-#define Py_UNICODE_JOIN_SURROGATES(high, low)  \
-    (((((Py_UCS4)(high) & 0x03FF) << 10) |      \
-      ((Py_UCS4)(low) & 0x03FF)) + 0x10000)
-/* high surrogate = top 10 bits added to D800 */
-#define Py_UNICODE_HIGH_SURROGATE(ch) (0xD800 - (0x10000 >> 10) + ((ch) >> 10))
-/* low surrogate = bottom 10 bits added to DC00 */
-#define Py_UNICODE_LOW_SURROGATE(ch) (0xDC00 + ((ch) & 0x3FF))
+// Low surrogate = bottom 10 bits added to DC00
+static inline Py_UCS4 Py_UNICODE_LOW_SURROGATE(Py_UCS4 ch) {
+    return (0xDC00 + (ch & 0x3FF));
+}
 
 /* --- Unicode Type ------------------------------------------------------- */
 
@@ -1013,10 +991,6 @@ PyAPI_FUNC(Py_ssize_t) _PyUnicode_InsertThousandsGrouping(
 
 /* === Characters Type APIs =============================================== */
 
-/* Helper array used by Py_UNICODE_ISSPACE(). */
-
-PyAPI_DATA(const unsigned char) _Py_ascii_whitespace[];
-
 /* These should not be used directly. Use the Py_UNICODE_IS* and
    Py_UNICODE_TO* macros instead.
 
@@ -1124,6 +1098,50 @@ PyAPI_FUNC(int) _PyUnicode_IsAlpha(
     Py_UCS4 ch       /* Unicode character */
     );
 
+// Helper array used by Py_UNICODE_ISSPACE().
+PyAPI_DATA(const unsigned char) _Py_ascii_whitespace[];
+
+// Since splitting on whitespace is an important use case, and
+// whitespace in most situations is solely ASCII whitespace, we
+// optimize for the common case by using a quick look-up table
+// _Py_ascii_whitespace (see below) with an inlined check.
+static inline int Py_UNICODE_ISSPACE(Py_UCS4 ch) {
+    if (ch < 128) {
+        return _Py_ascii_whitespace[ch];
+    }
+    return _PyUnicode_IsWhitespace(ch);
+}
+
+#define Py_UNICODE_ISLOWER(ch) _PyUnicode_IsLowercase(ch)
+#define Py_UNICODE_ISUPPER(ch) _PyUnicode_IsUppercase(ch)
+#define Py_UNICODE_ISTITLE(ch) _PyUnicode_IsTitlecase(ch)
+#define Py_UNICODE_ISLINEBREAK(ch) _PyUnicode_IsLinebreak(ch)
+
+#define Py_UNICODE_TOLOWER(ch) _PyUnicode_ToLowercase(ch)
+#define Py_UNICODE_TOUPPER(ch) _PyUnicode_ToUppercase(ch)
+#define Py_UNICODE_TOTITLE(ch) _PyUnicode_ToTitlecase(ch)
+
+#define Py_UNICODE_ISDECIMAL(ch) _PyUnicode_IsDecimalDigit(ch)
+#define Py_UNICODE_ISDIGIT(ch) _PyUnicode_IsDigit(ch)
+#define Py_UNICODE_ISNUMERIC(ch) _PyUnicode_IsNumeric(ch)
+#define Py_UNICODE_ISPRINTABLE(ch) _PyUnicode_IsPrintable(ch)
+
+#define Py_UNICODE_TODECIMAL(ch) _PyUnicode_ToDecimalDigit(ch)
+#define Py_UNICODE_TODIGIT(ch) _PyUnicode_ToDigit(ch)
+#define Py_UNICODE_TONUMERIC(ch) _PyUnicode_ToNumeric(ch)
+
+#define Py_UNICODE_ISALPHA(ch) _PyUnicode_IsAlpha(ch)
+
+static inline int Py_UNICODE_ISALNUM(Py_UCS4 ch) {
+   return (Py_UNICODE_ISALPHA(ch)
+           || Py_UNICODE_ISDECIMAL(ch)
+           || Py_UNICODE_ISDIGIT(ch)
+           || Py_UNICODE_ISNUMERIC(ch));
+}
+
+
+/* === Misc functions ===================================================== */
+
 PyAPI_FUNC(PyObject*) _PyUnicode_FormatLong(PyObject *, int, int, int);
 
 /* Return an interned Unicode object for an Identifier; may fail if there is no memory.*/