[Bug lto/78529] [7 Regression] gcc.c-torture/execute/builtins/strcat-chk.c failed with lto/O2

[rguenther at suse dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78529

--- Comment #33 from rguenther at suse dot de <rguenther at suse dot de> ---
On Wed, 22 Mar 2017, jakub at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78529
> 
> --- Comment #32 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
> It is actually the *-lib.c files that should be -fno-lto.
> But it seems all the source files are compiled/linked using one driver
> invocation, so I have no idea how to do -fno-lto just for one file.

Somehow change builtins.exp from

foreach src [lsort [find $srcdir/$subdir *.c]] {
    if {![string match *-lib.c $src] && [runtest_file_p $runtests $src]} {
        c-torture-execute [list $src \
                                [file root $src]-lib.c \
                                $srcdir/$subdir/lib/main.c] \
                                $additional_flags

to first compile [file root $src]-lib.c to [file root $src]-lib.o
and then do

        c-torture-execute [list $src \
                                [file root $src]-lib.o \
                                $srcdir/$subdir/lib/main.c] \
                                $additional_flags

?  Using gcc_target_compile in some way, like

        gcc_target_compile [file root $src]-lib.c [file root $src]-lib.o