From 64b56eaa3961038302ea3a8cc20d1f39c8d03c01 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin (Intel)" Date: Wed, 12 Dec 2018 15:56:28 -0800 Subject: configure: add -Wno-shift-negative-value Shifting negative values is undefined in standard C, but we have tons of dependencies that signed arithmetic is 2's-complement in the code anyway, and on gcc-like compilers we pass the -fwrapv option to indicate exactly that. Therefore, this is not a valid warning in our case and should be suppressed. Signed-off-by: H. Peter Anvin (Intel) --- configure.ac | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'configure.ac') diff --git a/configure.ac b/configure.ac index e707158c..38b3b596 100644 --- a/configure.ac +++ b/configure.ac @@ -281,6 +281,11 @@ PA_ADD_CFLAGS([-Wlong-long],[-Wno-long-long]) dnl This is needed because we intentionally expect strncpy() to fill dnl in a zero-padded (not zero-terminated) buffer in several backends PA_ADD_CFLAGS([-Wstringop-truncation],[-Wno-stringop-truncation]) +dnl This is needed because we assume 2's-completement signed arithmetic; +dnl on compilers with gcc-like command line syntax we pass the -fwrapv +dnl option for exactly that reason. +PA_ADD_CFLAGS([-Wshift-negative-value],[-Wno-shift-negative-value]) + dnl PA_ADD_CFLAGS([-Wwrite-strings]) PA_ARG_ENABLED([werror], [compile with -Werror to error out on any warning], -- cgit v1.2.1