Fixed a number of compiler warnings (#239)

* Fixed incorrect format specifiers when calling sprintf()
* Fixed potentially uninitialized variable
* Removed unused variables

Author: glaubitz

docs/versionhistory.rst

@@ -8,6 +8,7 @@ This library adheres to `Semantic Versioning <http://semver.org/>`_.
 **UNRELEASED**
 
 - Fixed compilation of C extension failing on GCC 14
+- Fixed compiler warnings when building C extension
 
 **5.6.3** (2024-04-11)
 

source/decoder.c

@@ -1,6 +1,7 @@
 #define PY_SSIZE_T_CLEAN
 #include <Python.h>
 #include <datetime.h>
+#include <inttypes.h>
 #include <string.h>
 #include <stdbool.h>
 #include <limits.h>
@@ -694,7 +695,7 @@ decode_bytestring(CBORDecoderObject *self, uint8_t subtype)
         return NULL;
 
     if (length > (uint64_t)PY_SSIZE_T_MAX - (uint64_t)PyBytesObject_SIZE) {
-        sprintf(length_hex, "%llX", length);
+        sprintf(length_hex, "%" PRIX64, length);
         PyErr_Format(
                 _CBOR2_CBORDecodeValueError,
                 "excessive bytestring size 0x%s", length_hex);
@@ -894,7 +895,7 @@ decode_string(CBORDecoderObject *self, uint8_t subtype)
     if (decode_length(self, subtype, &length, &indefinite) == -1)
         return NULL;
     if (length > (uint64_t)PY_SSIZE_T_MAX - (uint64_t)PyBytesObject_SIZE) {
-        sprintf(length_hex, "%llX", length);
+        sprintf(length_hex, "%" PRIX64, length);
         PyErr_Format(
                 _CBOR2_CBORDecodeValueError,
                 "excessive string size 0x%s", length_hex);
@@ -1057,7 +1058,7 @@ decode_array(CBORDecoderObject *self, uint8_t subtype)
     if (indefinite)
         return decode_indefinite_array(self);
     if (length > (uint64_t)PY_SSIZE_T_MAX) {
-        sprintf(length_hex, "%llX", length);
+        sprintf(length_hex, "%" PRIX64, length);
         PyErr_Format(
                 _CBOR2_CBORDecodeValueError,
                 "excessive array size 0x%s", length_hex);

source/encoder.c

@@ -1040,8 +1040,6 @@ CBOREncoder_encode_date(CBOREncoderObject *self, PyObject *value)
     // semantic type 100 or 1004
 
     PyObject *tmp, *ret = NULL;
-    const char *buf;
-    Py_ssize_t length;
     if (self->date_as_datetime) {
         tmp = PyDateTimeAPI->DateTime_FromDateAndTime(
                 PyDateTime_GET_YEAR(value),
@@ -1120,7 +1118,7 @@ decimal_negative(PyObject *value)
 static PyObject *
 encode_decimal_digits(CBOREncoderObject *self, PyObject *value)
 {
-    PyObject *tuple, *digits, *exp, *sig, *ten, *tmp, *ret = NULL;
+    PyObject *tuple, *digits, *exp, *sig, *ten, *tmp = NULL, *ret = NULL;
     int sign = 0;
     bool sharing;