Merge in release25-maint r60793:
Added checks for integer overflows, contributed by Google. Some are
only available if asserts are left in the code, in cases where they
can't be triggered from Python code.
diff --git a/Include/pyport.h b/Include/pyport.h
index 7c684f7..15c8644 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -117,6 +117,17 @@
# error "Python needs a typedef for Py_ssize_t in pyport.h."
#endif
+/* Largest possible value of size_t.
+ SIZE_MAX is part of C99, so it might be defined on some
+ platforms. If it is not defined, (size_t)-1 is a portable
+ definition for C89, due to the way signed->unsigned
+ conversion is defined. */
+#ifdef SIZE_MAX
+#define PY_SIZE_MAX SIZE_MAX
+#else
+#define PY_SIZE_MAX ((size_t)-1)
+#endif
+
/* Largest positive value of type Py_ssize_t. */
#define PY_SSIZE_T_MAX ((Py_ssize_t)(((size_t)-1)>>1))
/* Smallest negative value of type Py_ssize_t. */