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
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index 1d45c7a..3a9ce93 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -2025,7 +2025,7 @@
{
if (kind == PyUnicode_1BYTE_KIND) {
assert(ch < 256);
- return (char *) memchr((void *) s, (char) ch, end - s);
+ return (char *) memchr((const void *) s, (char) ch, end - s);
}
for (;;) {
while (PyUnicode_READ(kind, s, 0) > ch)
@@ -2043,7 +2043,7 @@
int translated, int universal, PyObject *readnl,
int kind, const char *start, const char *end, Py_ssize_t *consumed)
{
- Py_ssize_t len = ((char*)end - (char*)start)/kind;
+ Py_ssize_t len = (end - start)/kind;
if (translated) {
/* Newlines are already translated, only search for \n */