Re: tools/lib/lk: redefinition of _FORTIFY_SOURCE (gcc-4.7.2)

[Dirk Gouders]

Dirk Gouders <dirk@xxxxxxxxxxx> writes:

> What probably might help in any case is undefining _FORTIFY_SOURCE before
> defining it, because as far as I know, there is no problem with
> undefining something that is not yet defined, but I could imagine,
> others might have more elegant suggestions:
>
> CFLAGS = -ggdb3 -Wall -Wextra -std=gnu99 -Werror -O6 -U_FORTIFY_SOURCE
> -D_FORTIFY_SOURCE=2 $(EXTRA_WARNINGS) $(EXTRA_CFLAGS) -fPIC

More elegant would probably be to look at tools/perf/Makefile and handle
the problem as is done there:

CFLAGS = -ggdb3 -Wall -Wextra -std=gnu99 -Werror -O6 $(EXTRA_WARNINGS) $(EXTRA_CFLAGS) -fPIC

ifeq ($(call try-cc,$(SOURCE_HELLO),$(CFLAGS) -D_FORTIFY_SOURCE=2,-D_FORTIFY_SOURCE=2),y)
               CFLAGS := $(CFLAGS) -D_FORTIFY_SOURCE=2
endif

I tested it here and it works well.

Dirk
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