From 2d6d099fed05b1509e81e54458516528bfbbf38d Mon Sep 17 00:00:00 2001 From: Vaibhav Jain Date: Tue, 21 May 2019 12:06:16 +0530 Subject: [PATCH] Fix GCC-9.1 warning with macro GET_ARG_NUMERIC MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit GCC-9.1 reports following error when trying to compile file src/malloc_io.c and with CFLAGS='-Werror' : src/malloc_io.c: In function ‘malloc_vsnprintf’: src/malloc_io.c:369:2: error: case label value exceeds maximum value for type [-Werror] 369 | case '?' | 0x80: \ | ^~~~ src/malloc_io.c:581:5: note: in expansion of macro ‘GET_ARG_NUMERIC’ 581 | GET_ARG_NUMERIC(val, 'p'); | ^~~~~~~~~~~~~~~ ... cc1: all warnings being treated as errors make: *** [Makefile:388: src/malloc_io.sym.o] Error 1 The warning is reported as by default the type 'char' is 'signed char' and or-ing 0x80 will turn the case label char negative which will be beyond the printable ascii range (0 - 127). The patch fixes this by explicitly casting the 'len' variable as unsigned char' inside the 'switch' statement so that value of expression " '?' | 0x80 " falls within the legal values of the variable 'len'. --- src/malloc_io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/malloc_io.c b/src/malloc_io.c index 7bdc13f9..dd882651 100644 --- a/src/malloc_io.c +++ b/src/malloc_io.c @@ -362,7 +362,7 @@ malloc_vsnprintf(char *str, size_t size, const char *format, va_list ap) { } \ } while (0) #define GET_ARG_NUMERIC(val, len) do { \ - switch (len) { \ + switch ((unsigned char)len) { \ case '?': \ val = va_arg(ap, int); \ break; \