When building the project with "make DESTDIR=... install", the root Makefile defines CFLAGS and LDFLAGS without any warning flags ("CFLAGS += -I$(DESTDIR)/usr/include" and "LDFLAGS += -L$(DESTDIR)/usr/lib"). As the Makefiles in subdirectories do not override the flags with warning flags, the code gets compiled without any enabled warning. This leads for example to code being introduced which breaks building libsepol from its directory, while building it from the root Makefile still works fine. This issue can be fixed by defining a set of flags in the root Makefile which are used by all Makefiles in subdirectories. The flags have been chosen following these principles: * they are compatible with both clang and gcc, * they already appear in at least one Makefile, and * they are not triggered with the current git master version. Signed-off-by: Nicolas Iooss <nicolas.iooss@xxxxxxx> --- Makefile | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Makefile b/Makefile index 7701e16252fe..6da7f7b71bdc 100644 --- a/Makefile +++ b/Makefile @@ -6,6 +6,16 @@ DISTCLEANSUBDIRS=libselinux libsemanage ifeq ($(DEBUG),1) export CFLAGS = -g3 -O0 -gdwarf-2 -fno-strict-aliasing -Wall -Wshadow -Werror export LDFLAGS = -g +else + export CFLAGS ?= -O2 -Werror -Wall -Wextra \ + -Wmissing-format-attribute \ + -Wmissing-noreturn \ + -Wpointer-arith \ + -Wshadow \ + -Wstrict-prototypes \ + -Wundef \ + -Wunused \ + -Wwrite-strings endif ifneq ($(DESTDIR),) -- 2.14.1