commit 190433d8150bf719fa0ba972dbacf2214942f54e
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Tue Feb 11 18:47:20 2020 -0800
committer GitHub <noreply@github.com> Tue Feb 11 18:47:20 2020 -0800
tree 542d09915c36b8e496c0c66950eb0bf29704e271
parent 0f0d2e496205c345b182b6572ee09db23f8f9daf

closes bpo-39605: Fix some casts to not cast away const. (GH-18453)


gcc -Wcast-qual turns up a number of instances of casting away constness of pointers. Some of these can be safely modified, by either:

Adding the const to the type cast, as in:

-    return _PyUnicode_FromUCS1((unsigned char*)s, size);
+    return _PyUnicode_FromUCS1((const unsigned char*)s, size);

or, Removing the cast entirely, because it's not necessary (but probably was at one time), as in:

-    PyDTrace_FUNCTION_ENTRY((char *)filename, (char *)funcname, lineno);
+    PyDTrace_FUNCTION_ENTRY(filename, funcname, lineno);

These changes will not change code, but they will make it much easier to check for errors in consts
(cherry picked from commit e6be9b59a911626d6597fe148c32f0342bd2bd24)

Co-authored-by: Andy Lester <andy@petdance.com>

Objects/bytes_methods.c

diff --git a/Objects/bytes_methods.c b/Objects/bytes_methods.c
index 7d13184..db030be 100644
--- a/Objects/bytes_methods.c
+++ b/Objects/bytes_methods.c
@@ -12,7 +12,7 @@
 _Py_bytes_isspace(const char *cptr, Py_ssize_t len)
 {
     const unsigned char *p
-        = (unsigned char *) cptr;
+        = (const unsigned char *) cptr;
     const unsigned char *e;
 
     /* Shortcut for single character strings */
@@ -42,7 +42,7 @@
 _Py_bytes_isalpha(const char *cptr, Py_ssize_t len)
 {
     const unsigned char *p
-        = (unsigned char *) cptr;
+        = (const unsigned char *) cptr;
     const unsigned char *e;
 
     /* Shortcut for single character strings */
@@ -72,7 +72,7 @@
 _Py_bytes_isalnum(const char *cptr, Py_ssize_t len)
 {
     const unsigned char *p
-        = (unsigned char *) cptr;
+        = (const unsigned char *) cptr;
     const unsigned char *e;
 
     /* Shortcut for single character strings */
@@ -123,7 +123,7 @@
             /* Help allocation */
             const char *_p = p;
             while (_p < aligned_end) {
-                unsigned long value = *(unsigned long *) _p;
+                unsigned long value = *(const unsigned long *) _p;
                 if (value & ASCII_CHAR_MASK) {
                     Py_RETURN_FALSE;
                 }
@@ -154,7 +154,7 @@
 _Py_bytes_isdigit(const char *cptr, Py_ssize_t len)
 {
     const unsigned char *p
-        = (unsigned char *) cptr;
+        = (const unsigned char *) cptr;
     const unsigned char *e;
 
     /* Shortcut for single character strings */
@@ -184,7 +184,7 @@
 _Py_bytes_islower(const char *cptr, Py_ssize_t len)
 {
     const unsigned char *p
-        = (unsigned char *) cptr;
+        = (const unsigned char *) cptr;
     const unsigned char *e;
     int cased;
 
@@ -218,7 +218,7 @@
 _Py_bytes_isupper(const char *cptr, Py_ssize_t len)
 {
     const unsigned char *p
-        = (unsigned char *) cptr;
+        = (const unsigned char *) cptr;
     const unsigned char *e;
     int cased;
 
@@ -254,7 +254,7 @@
 _Py_bytes_istitle(const char *cptr, Py_ssize_t len)
 {
     const unsigned char *p
-        = (unsigned char *) cptr;
+        = (const unsigned char *) cptr;
     const unsigned char *e;
     int cased, previous_is_cased;