On 08/03/2016 09:45 AM, David Malcolm wrote:
This adds fix-it hints to c-format.c so that it can (sometimes) suggest
the format string the user should have used.
The patch adds selftests for the new code in c-format.c. These
selftests are thus lang-specific. This is the first time we've had
lang-specific selftests, and hence the patch also adds a langhook for
running them. (Note that currently the Makefile only invokes the
selftests for cc1).
Successfully bootstrapped®rtested in conjunction with the rest of the
patch kit on x86_64-pc-linux-gnu.
(The v2 version of the patch had a successful selftest run for stage 1 on
powerpc-ibm-aix7.1.3.0 (gcc111) in conjunction with the rest of the patch
kit, and a successful build of stage1 for all targets via config-list.mk;
the patch has only been rebased since)
OK for trunk if it passes testing?
gcc/c-family/ChangeLog:
PR c/64955
* c-common.h (selftest::c_format_c_tests): New declaration.
(selftest::run_c_tests): New declaration.
* c-format.c: Include "selftest.h.
(format_warning_va): Add param "corrected_substring" and use
it to add a replacement fix-it hint.
(format_warning_at_substring): Likewise.
(format_warning_at_char): Update for new param of
format_warning_va.
(check_format_info_main): Pass "fki" to check_format_types.
(check_format_types): Add param "fki" and pass it to
format_type_warning.
(deref_n_times): New function.
(get_modifier_for_format_len): New function.
(selftest::test_get_modifier_for_format_len): New function.
(get_format_for_type): New function.
(format_type_warning): Add param "fki" and use it to attempt
to provide hints for argument types when calling
format_warning_at_substring.
(selftest::get_info): New function.
(selftest::assert_format_for_type_streq): New function.
(ASSERT_FORMAT_FOR_TYPE_STREQ): New macro.
(selftest::test_get_format_for_type_printf): New function.
(selftest::test_get_format_for_type_scanf): New function.
(selftest::c_format_c_tests): New function.
gcc/c/ChangeLog:
PR c/64955
* c-lang.c (LANG_HOOKS_RUN_LANG_SELFTESTS): If CHECKING_P, wire
this up to selftest::run_c_tests.
(selftest::run_c_tests): New function.
gcc/ChangeLog:
PR c/64955
* langhooks-def.h (LANG_HOOKS_RUN_LANG_SELFTESTS): New default
do-nothing langhook.
(LANG_HOOKS_INITIALIZER): Add LANG_HOOKS_RUN_LANG_SELFTESTS.
* langhooks.h (struct lang_hooks): Add run_lang_selftests.
* selftest-run-tests.c: Include "tree.h" and "langhooks.h".
(selftest::run_tests): Call lang_hooks.run_lang_selftests.
gcc/testsuite/ChangeLog:
PR c/64955
* gcc.dg/format/diagnostic-ranges.c: Add fix-it hints to expected
output.
So presumably we always use the type of the argument as the "correct"
type and assume the format string is what needs to be fixed (with the
exception of getting the right amount of *s handled). That seems
intuitively the right thing to do, but do we have a hit rate better than
50% in practice?
This is OK. I'm really just curious about your thoughts/experiences on
the heuristics.
jeff
