Issue #13088: Add shared Py_hexdigits constant to format a number into base 16

Include/codecs.h

@@ -174,6 +174,8 @@ PyAPI_FUNC(PyObject *) PyCodec_XMLCharRefReplaceErrors(PyObject *exc);
 /* replace the unicode encode error with backslash escapes (\x, \u and \U) */
 PyAPI_FUNC(PyObject *) PyCodec_BackslashReplaceErrors(PyObject *exc);
 
+extern const char *Py_hexdigits;
+
 #ifdef __cplusplus
 }
 #endif

Modules/_codecsmodule.c

@@ -162,7 +162,6 @@ static PyObject *
 escape_encode(PyObject *self,
               PyObject *args)
 {
-    static const char *hexdigits = "0123456789abcdef";
     PyObject *str;
     Py_ssize_t size;
     Py_ssize_t newsize;
@@ -205,8 +204,8 @@ escape_encode(PyObject *self,
             else if (c < ' ' || c >= 0x7f) {
                 *p++ = '\\';
                 *p++ = 'x';
-                *p++ = hexdigits[(c & 0xf0) >> 4];
-                *p++ = hexdigits[c & 0xf];
+                *p++ = Py_hexdigits[(c & 0xf0) >> 4];
+                *p++ = Py_hexdigits[c & 0xf];
             }
             else
                 *p++ = c;

Modules/_hashopenssl.c

@@ -201,13 +201,11 @@ EVP_hexdigest(EVPobject *self, PyObject *unused)
 
     /* Make hex version of the digest */
     for(i=j=0; i<digest_size; i++) {
-        char c;
+        unsigned char c;
         c = (digest[i] >> 4) & 0xf;
-        c = (c>9) ? c+'a'-10 : c + '0';
-        hex_digest[j++] = c;
+        hex_digest[j++] = Py_hexdigits[c];
         c = (digest[i] & 0xf);
-        c = (c>9) ? c+'a'-10 : c + '0';
-        hex_digest[j++] = c;
+        hex_digest[j++] = Py_hexdigits[c];
     }
     retval = PyUnicode_FromStringAndSize(hex_digest, digest_size * 2);
     PyMem_Free(hex_digest);

Modules/_json.c

@@ -175,18 +175,18 @@ ascii_escape_unichar(Py_UCS4 c, unsigned char *output, Py_ssize_t chars)
                 Py_UCS4 v = c - 0x10000;
                 c = 0xd800 | ((v >> 10) & 0x3ff);
                 output[chars++] = 'u';
-                output[chars++] = "0123456789abcdef"[(c >> 12) & 0xf];
-                output[chars++] = "0123456789abcdef"[(c >>  8) & 0xf];
-                output[chars++] = "0123456789abcdef"[(c >>  4) & 0xf];
-                output[chars++] = "0123456789abcdef"[(c      ) & 0xf];
+                output[chars++] = Py_hexdigits[(c >> 12) & 0xf];
+                output[chars++] = Py_hexdigits[(c >>  8) & 0xf];
+                output[chars++] = Py_hexdigits[(c >>  4) & 0xf];
+                output[chars++] = Py_hexdigits[(c      ) & 0xf];
                 c = 0xdc00 | (v & 0x3ff);
                 output[chars++] = '\\';
             }
             output[chars++] = 'u';
-            output[chars++] = "0123456789abcdef"[(c >> 12) & 0xf];
-            output[chars++] = "0123456789abcdef"[(c >>  8) & 0xf];
-            output[chars++] = "0123456789abcdef"[(c >>  4) & 0xf];
-            output[chars++] = "0123456789abcdef"[(c      ) & 0xf];
+            output[chars++] = Py_hexdigits[(c >> 12) & 0xf];
+            output[chars++] = Py_hexdigits[(c >>  8) & 0xf];
+            output[chars++] = Py_hexdigits[(c >>  4) & 0xf];
+            output[chars++] = Py_hexdigits[(c      ) & 0xf];
     }
     return chars;
 }

Modules/_pickle.c

@@ -1776,7 +1776,6 @@ save_bytes(PicklerObject *self, PyObject *obj)
 static PyObject *
 raw_unicode_escape(PyObject *obj)
 {
-    static const char *hexdigits = "0123456789abcdef";
     PyObject *repr, *result;
     char *p;
     Py_ssize_t i, size, expandsize;
@@ -1809,23 +1808,23 @@ raw_unicode_escape(PyObject *obj)
         if (ch >= 0x10000) {
             *p++ = '\\';
             *p++ = 'U';
-            *p++ = hexdigits[(ch >> 28) & 0xf];
-            *p++ = hexdigits[(ch >> 24) & 0xf];
-            *p++ = hexdigits[(ch >> 20) & 0xf];
-            *p++ = hexdigits[(ch >> 16) & 0xf];
-            *p++ = hexdigits[(ch >> 12) & 0xf];
-            *p++ = hexdigits[(ch >> 8) & 0xf];
-            *p++ = hexdigits[(ch >> 4) & 0xf];
-            *p++ = hexdigits[ch & 15];
+            *p++ = Py_hexdigits[(ch >> 28) & 0xf];
+            *p++ = Py_hexdigits[(ch >> 24) & 0xf];
+            *p++ = Py_hexdigits[(ch >> 20) & 0xf];
+            *p++ = Py_hexdigits[(ch >> 16) & 0xf];
+            *p++ = Py_hexdigits[(ch >> 12) & 0xf];
+            *p++ = Py_hexdigits[(ch >> 8) & 0xf];
+            *p++ = Py_hexdigits[(ch >> 4) & 0xf];
+            *p++ = Py_hexdigits[ch & 15];
         }
         /* Map 16-bit characters to '\uxxxx' */
         else if (ch >= 256 || ch == '\\' || ch == '\n') {
             *p++ = '\\';
             *p++ = 'u';
-            *p++ = hexdigits[(ch >> 12) & 0xf];
-            *p++ = hexdigits[(ch >> 8) & 0xf];
-            *p++ = hexdigits[(ch >> 4) & 0xf];
-            *p++ = hexdigits[ch & 15];
+            *p++ = Py_hexdigits[(ch >> 12) & 0xf];
+            *p++ = Py_hexdigits[(ch >> 8) & 0xf];
+            *p++ = Py_hexdigits[(ch >> 4) & 0xf];
+            *p++ = Py_hexdigits[ch & 15];
         }
         /* Copy everything else as-is */
         else

Modules/binascii.c

@@ -1078,13 +1078,11 @@ binascii_hexlify(PyObject *self, PyObject *args)
 
     /* make hex version of string, taken from shamodule.c */
     for (i=j=0; i < arglen; i++) {
-        char c;
+        unsigned char c;
         c = (argbuf[i] >> 4) & 0xf;
-        c = (c>9) ? c+'a'-10 : c + '0';
-        retbuf[j++] = c;
+        retbuf[j++] = Py_hexdigits[c];
         c = argbuf[i] & 0xf;
-        c = (c>9) ? c+'a'-10 : c + '0';
-        retbuf[j++] = c;
+        retbuf[j++] = Py_hexdigits[c];
     }
     PyBuffer_Release(&parg);
     return retval;

Modules/md5module.c

@@ -391,13 +391,11 @@ MD5_hexdigest(MD5object *self, PyObject *unused)
 
     /* Make hex version of the digest */
     for(i=j=0; i<MD5_DIGESTSIZE; i++) {
-        char c;
+        unsigned char c;
         c = (digest[i] >> 4) & 0xf;
-        c = (c>9) ? c+'a'-10 : c + '0';
-        hex_digest[j++] = c;
+        hex_digest[j++] = Py_hexdigits[c];
         c = (digest[i] & 0xf);
-        c = (c>9) ? c+'a'-10 : c + '0';
-        hex_digest[j++] = c;
+        hex_digest[j++] = Py_hexdigits[c];
     }
     return retval;
 }

Modules/sha1module.c

@@ -367,13 +367,11 @@ SHA1_hexdigest(SHA1object *self, PyObject *unused)
 
     /* Make hex version of the digest */
     for(i=j=0; i<SHA1_DIGESTSIZE; i++) {
-        char c;
+        unsigned char c;
         c = (digest[i] >> 4) & 0xf;
-        c = (c>9) ? c+'a'-10 : c + '0';
-        hex_digest[j++] = c;
+        hex_digest[j++] = Py_hexdigits[c];
         c = (digest[i] & 0xf);
-        c = (c>9) ? c+'a'-10 : c + '0';
-        hex_digest[j++] = c;
+        hex_digest[j++] = Py_hexdigits[c];
     }
     return retval;
 }

Modules/sha256module.c

@@ -460,13 +460,11 @@ SHA256_hexdigest(SHAobject *self, PyObject *unused)
 
     /* Make hex version of the digest */
     for(i=j=0; i<self->digestsize; i++) {
-        char c;
+        unsigned char c;
         c = (digest[i] >> 4) & 0xf;
-        c = (c>9) ? c+'a'-10 : c + '0';
-        hex_digest[j++] = c;
+        hex_digest[j++] = Py_hexdigits[c];
         c = (digest[i] & 0xf);
-        c = (c>9) ? c+'a'-10 : c + '0';
-        hex_digest[j++] = c;
+        hex_digest[j++] = Py_hexdigits[c];
     }
     return retval;
 }

Modules/sha512module.c

@@ -526,13 +526,11 @@ SHA512_hexdigest(SHAobject *self, PyObject *unused)
 
     /* Make hex version of the digest */
     for (i=j=0; i<self->digestsize; i++) {
-        char c;
+        unsigned char c;
         c = (digest[i] >> 4) & 0xf;
-        c = (c>9) ? c+'a'-10 : c + '0';
-        hex_digest[j++] = c;
+        hex_digest[j++] = Py_hexdigits[c];
         c = (digest[i] & 0xf);
-        c = (c>9) ? c+'a'-10 : c + '0';
-        hex_digest[j++] = c;
+        hex_digest[j++] = Py_hexdigits[c];
     }
     return retval;
 }

Objects/bytearrayobject.c

@@ -850,7 +850,6 @@ bytearray_init(PyByteArrayObject *self, PyObject *args, PyObject *kwds)
 static PyObject *
 bytearray_repr(PyByteArrayObject *self)
 {
-    static const char *hexdigits = "0123456789abcdef";
     const char *quote_prefix = "bytearray(b";
     const char *quote_postfix = ")";
     Py_ssize_t length = Py_SIZE(self);
@@ -912,8 +911,8 @@ bytearray_repr(PyByteArrayObject *self)
         else if (c < ' ' || c >= 0x7f) {
             *p++ = '\\';
             *p++ = 'x';
-            *p++ = hexdigits[(c & 0xf0) >> 4];
-            *p++ = hexdigits[c & 0xf];
+            *p++ = Py_hexdigits[(c & 0xf0) >> 4];
+            *p++ = Py_hexdigits[c & 0xf];
         }
         else
             *p++ = c;

Objects/bytesobject.c

@@ -564,7 +564,6 @@ PyBytes_AsStringAndSize(register PyObject *obj,
 PyObject *
 PyBytes_Repr(PyObject *obj, int smartquotes)
 {
-    static const char *hexdigits = "0123456789abcdef";
     register PyBytesObject* op = (PyBytesObject*) obj;
     Py_ssize_t i, length = Py_SIZE(op);
     size_t newsize, squotes, dquotes;
@@ -620,8 +619,8 @@ PyBytes_Repr(PyObject *obj, int smartquotes)
         else if (c < ' ' || c >= 0x7f) {
             *p++ = '\\';
             *p++ = 'x';
-            *p++ = hexdigits[(c & 0xf0) >> 4];
-            *p++ = hexdigits[c & 0xf];
+            *p++ = Py_hexdigits[(c & 0xf0) >> 4];
+            *p++ = Py_hexdigits[c & 0xf];
         }
         else
             *p++ = c;

Objects/floatobject.c

@@ -1058,7 +1058,7 @@ static char
 char_from_hex(int x)
 {
     assert(0 <= x && x < 16);
-    return "0123456789abcdef"[x];
+    return Py_hexdigits[x];
 }
 
 static int

Python/codecs.c

@@ -11,6 +11,8 @@ Copyright (c) Corporation for National Research Initiatives.
 #include "Python.h"
 #include <ctype.h>
 
+const char *Py_hexdigits = "0123456789abcdef";
+
 /* --- Codec Registry ----------------------------------------------------- */
 
 /* Import the standard encodings package which will register the first
@@ -673,8 +675,6 @@ PyObject *PyCodec_XMLCharRefReplaceErrors(PyObject *exc)
     }
 }
 
-static const char *hexdigits = "0123456789abcdef";
-
 PyObject *PyCodec_BackslashReplaceErrors(PyObject *exc)
 {
 #ifndef Py_UNICODE_WIDE
@@ -731,22 +731,22 @@ PyObject *PyCodec_BackslashReplaceErrors(PyObject *exc)
             }
             if (c >= 0x00010000) {
                 *outp++ = 'U';
-                *outp++ = hexdigits[(c>>28)&0xf];
-                *outp++ = hexdigits[(c>>24)&0xf];
-                *outp++ = hexdigits[(c>>20)&0xf];
-                *outp++ = hexdigits[(c>>16)&0xf];
-                *outp++ = hexdigits[(c>>12)&0xf];
-                *outp++ = hexdigits[(c>>8)&0xf];
+                *outp++ = Py_hexdigits[(c>>28)&0xf];
+                *outp++ = Py_hexdigits[(c>>24)&0xf];
+                *outp++ = Py_hexdigits[(c>>20)&0xf];
+                *outp++ = Py_hexdigits[(c>>16)&0xf];
+                *outp++ = Py_hexdigits[(c>>12)&0xf];
+                *outp++ = Py_hexdigits[(c>>8)&0xf];
             }
             else if (c >= 0x100) {
                 *outp++ = 'u';
-                *outp++ = hexdigits[(c>>12)&0xf];
-                *outp++ = hexdigits[(c>>8)&0xf];
+                *outp++ = Py_hexdigits[(c>>12)&0xf];
+                *outp++ = Py_hexdigits[(c>>8)&0xf];
             }
             else
                 *outp++ = 'x';
-            *outp++ = hexdigits[(c>>4)&0xf];
-            *outp++ = hexdigits[c&0xf];
+            *outp++ = Py_hexdigits[(c>>4)&0xf];
+            *outp++ = Py_hexdigits[c&0xf];
         }
 
         restuple = Py_BuildValue("(On)", res, end);

Python/traceback.c

@@ -463,12 +463,11 @@ dump_decimal(int fd, int value)
 static void
 dump_hexadecimal(int width, unsigned long value, int fd)
 {
-    const char *hexdigits = "0123456789abcdef";
     int len;
     char buffer[sizeof(unsigned long) * 2 + 1];
     len = 0;
     do {
-        buffer[len] = hexdigits[value & 15];
+        buffer[len] = Py_hexdigits[value & 15];
         value >>= 4;
         len++;
     } while (len < width || value);