On Thu, 17 Nov 2016, Christophe Lyon wrote:
> On 16 November 2016 at 10:35, Richard Biener <rguent...@suse.de> wrote:
> >
> > Since GCC 4.6 we aggressively prune bodies of GNU extern inline functions
> > which means that instrumenting them via -finstrument-functions doesn't
> > work because that takes the address of the function. Fixed by not
> > instrumenting those functions (we still instrument regular always-inline
> > functions and that works as expected).
> >
> > In the PR this affects intrinsic header functions but it will also
> > affect fortify wrappers and in both cases instrumenting is undesirable
> > I think.
> >
> > Bootstrap / regtest in progress on x86_64-unknown-linux-gnu.
> >
> > Richard.
> >
> > 2016-11-16 Richard Biener <rguent...@suse.de>
> >
> > PR middle-end/78333
> > * gimplify.c (gimplify_function_tree): Do not instrument
> > GNU extern inline functions.
> >
> > * gcc.dg/pr78333.c: New testcase.
> >
> > Index: gcc/gimplify.c
> > ===================================================================
> > --- gcc/gimplify.c (revision 242408)
> > +++ gcc/gimplify.c (working copy)
> > @@ -12547,6 +12559,10 @@ gimplify_function_tree (tree fndecl)
> > /* ??? Add some way to ignore exceptions for this TFE. */
> > if (flag_instrument_function_entry_exit
> > && !DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl)
> > + /* Do not instrument extern inline functions. */
> > + && !(DECL_DECLARED_INLINE_P (fndecl)
> > + && DECL_EXTERNAL (fndecl)
> > + && DECL_DISREGARD_INLINE_LIMITS (fndecl))
> > && !flag_instrument_functions_exclude_p (fndecl))
> > {
> > tree x;
> > Index: gcc/testsuite/gcc.dg/pr78333.c
> > ===================================================================
> > --- gcc/testsuite/gcc.dg/pr78333.c (revision 0)
> > +++ gcc/testsuite/gcc.dg/pr78333.c (working copy)
> > @@ -0,0 +1,9 @@
> > +/* { dg-do link } */
> > +/* { dg-options "-finstrument-functions" } */
> > +
> > +extern inline __attribute__((gnu_inline, always_inline)) int foo () { }
> > +int main()
> > +{
> > + foo ();
> > + return 0;
> > +}
>
> Hi Richard,
>
> The new testcase fails to link on bare-metal targets (arm/aarch64):
> /cc4ckSGA.o: In function `main':
> pr78333.c:(.text+0x1c): undefined reference to `__cyg_profile_func_enter'
> pr78333.c:(.text+0x34): undefined reference to `__cyg_profile_func_exit'
> collect2: error: ld returned 1 exit status
>
> I understand that we really want this test to have dg-do link unlike most
> of the other tests using -finstrument-functions, so we do not want to
> switch to dg-do compile.
Yes, we need a link test (maybe a very carefully crafted scan-assembler
test would also work...)
> Do we want to skip this test in bare-metal configs, or is it a new bug?
Is there some dg- target for "bare metal"? Can we use ! freestanding?
Otherwise does abusing sth like { dg-require-profiling
"-finstrument-functions" } work? (seems to just test if -pg works)
Thanks,
Richard.
