lib: Rewrite POINTER_CAST_TO() to avoid new clang warning

Fixes:
warning: performing pointer subtraction with a null pointer has undefined behavior [-Wnull-pointer-subtraction]

diff --git a/src/lib/macros.h b/src/lib/macros.h
index cecd56913a081d02cbd8cbf83aa2284ca6b450a6..c264ec6066b052e7bc44c87c5ae7a4b1b929aa3e 100644 (file)
--- a/src/lib/macros.h
+++ b/src/lib/macros.h
@@ -41,7 +41,7 @@
 #define POINTER_CAST(i) \
        ((void *) (((uintptr_t)NULL) + (i)))
 #define POINTER_CAST_TO(p, type) \
-       ((type) ((const char *) (p) - (const char *) NULL))
+       ((type)(uintptr_t)(p))
 
 /* Define VA_COPY() to do the right thing for copying va_list variables.
    config.h may have already defined VA_COPY as va_copy or __va_copy. */