[PATCH 1/2] build: disable GCC string op warnings when unoptimized

[Stephen Hemminger <stephen@networkplumber.org>]

Without optimization GCC produces warnings for unreachable code paths.
They check memcpy() against the object size even on paths that are dead
for the inlined arguments. This breaks debug builds of app/test
with -Werror on lib/stack/rte_stack_pile.h,
and has required local pragma workarounds elsewhere.

Disable both warnings when optimization is 0. They stay enabled for
optimized builds, where the analysis is flow-sensitive.

Bugzilla ID: 2061

Reported-by: Ali Alnubani <alialnu@nvidia.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 config/meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/config/meson.build b/config/meson.build
index 745097e8aa..bfac1cd93d 100644
--- a/config/meson.build
+++ b/config/meson.build
@@ -378,6 +378,12 @@ if cc.has_argument('-Wno-comma')
     no_comma_cflag = '-Wno-comma'
 endif
 
+# GCC's string/memory access warnings are flow-insensitive without
+# optimization and produce false positives on dead paths of inlined code.
+if get_option('optimization') == '0' and cc.get_id() == 'gcc'
+    global_cflags += ['-Wno-stringop-overflow', '-Wno-stringop-overread']
+endif
+
 foreach arg: global_cflags
     if cc.has_argument(arg)
         add_project_arguments(arg, language: 'c')
-- 
2.53.0