https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78086
--- Comment #3 from dave.anglin at bell dot net ---
On 2016-10-25, at 8:29 AM, dave.anglin at bell dot net wrote:
>> However, 'cannot open data file, assuming not executed' message is very
>> suspicious.
>
> The .gcda files are not being generated. Investigating.
The problem was introduced in r240529:
2016-09-27 Martin Liska <mli...@suse.cz>
PR gcov-profile/7970
PR gcov-profile/16855
PR gcov-profile/44779
* coverage.c (build_gcov_exit_decl): New function.
(coverage_obj_init): Call the function and generate __gcov_exit
destructor.
* doc/gcov.texi: Document when __gcov_exit function is called.
It appears to be issue with constructors/destructors. With gcc-6, we had:
.section .ctors,"aw",@progbits
.align 8
.dword P%_GLOBAL__sub_I_65535_0_noop
_GLOBAL__sub_I_65535_0_noop is called.
With r240529, we have:
.section .ctors.00001,"aw",@progbits
.align 8
.dword P%_GLOBAL__sub_I_65534_0_noop
[...]
.section .dtors.00001,"aw",@progbits
.align 8
.dword P%_GLOBAL__sub_D_65534_1_noop
Neither the constructor or destructor is called.
It looks to me like the priority change has changed the constructor section:
default_named_section_asm_out_constructor (rtx symbol, int priority)
{
section *sec;
if (priority != DEFAULT_INIT_PRIORITY)
sec = get_cdtor_priority_section (priority,
/*constructor_p=*/true);
else
sec = get_section (".ctors", SECTION_WRITE, NULL);
assemble_addr_to_section (symbol, sec);
}
Probably, defining CTORS_SECTION_ASM_OP and DTORS_SECTION_ASM_OP will fix.
On the other hand, I think SUPPORTS_INIT_PRIORITY is 0.
--
John David Anglin dave.ang...@bell.net
