On Mon, Sep 17, 2012 at 7:17 PM, Ian Lance Taylor <i...@google.com> wrote:
> This patch to the diagnostic code uses the new backtrace library to
> print a backtrace on an ICE. For example, here is the output of a test
> case I took from a C++ PR:
>
> /home/iant/foo2.cc:6:6: internal compiler error: in cp_lexer_new_from_tokens,
> at cp/parser.c:638
> 0xec549f internal_error(char const*, ...)
> ../../trunk/gcc/diagnostic.c:1057
> 0xec3f53 fancy_abort(char const*, int, char const*)
> ../../trunk/gcc/diagnostic.c:1111
> 0x5ff78e cp_lexer_new_from_tokens
> ../../trunk/gcc/cp/parser.c:638
> 0x5ff78e cp_parser_push_lexer_for_tokens
> ../../trunk/gcc/cp/parser.c:3290
> 0x60ff40 cp_parser_late_parsing_for_member
> ../../trunk/gcc/cp/parser.c:21713
> 0x60ff40 cp_parser_class_specifier_1
> ../../trunk/gcc/cp/parser.c:18207
> 0x60ff40 cp_parser_class_specifier
> ../../trunk/gcc/cp/parser.c:18231
> 0x60ff40 cp_parser_type_specifier
> ../../trunk/gcc/cp/parser.c:13390
> 0x61c83d cp_parser_decl_specifier_seq
> ../../trunk/gcc/cp/parser.c:10731
> 0x628317 cp_parser_single_declaration
> ../../trunk/gcc/cp/parser.c:21313
> 0x6289c0 cp_parser_template_declaration_after_export
> ../../trunk/gcc/cp/parser.c:21198
> 0x62de39 cp_parser_declaration
> ../../trunk/gcc/cp/parser.c:10183
> 0x62c487 cp_parser_declaration_seq_opt
> ../../trunk/gcc/cp/parser.c:10105
> 0x62c762 cp_parser_translation_unit
> ../../trunk/gcc/cp/parser.c:3757
> 0x62c762 c_parse_file()
> ../../trunk/gcc/cp/parser.c:27557
> 0x72e4e4 c_common_parse_file()
> ../../trunk/gcc/c-family/c-opts.c:1138
> Please submit a full bug report,
> with preprocessed source if appropriate.
> See <http://gcc.gnu.org/bugs.html> for instructions.
>
>
> Bootstrapped on x86_64-unknown-linux-gnu. I didn't bother to run the
> testsuite, since the code only changes when an ICE occurs anyhow.
>
> OK for mainline?
Hm. Can you please be that verbose only for ENABLE_CHECKING compilers?
I'd say that we should do sth fancy with the backtrace first, like in your
example note that it came from an assert (and skip the first two frames),
or more simple - skip frames until the function name we printed anyways
is listed. Then for !ENABLE_CHECKING I'd derive bugzilla components
(backtrace from the frontend? from which tree/RTL pass?).
I mean the above is so verbose that bugreporters likely will only paste the
last non-interesting lines like
0x62c762 cp_parser_translation_unit
../../trunk/gcc/cp/parser.c:3757
0x62c762 c_parse_file()
../../trunk/gcc/cp/parser.c:27557
0x72e4e4 c_common_parse_file()
../../trunk/gcc/c-family/c-opts.c:1138
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
also consider ICEs from infinite recursion - you'd get a way too large backtrace
(so please consider pruning recursions).
Or at least provide a way to disable the backtrace printing with a configure
switch.
Thanks,
Richard.
> Ian
>
> gcc/:
>
> 2012-09-17 Ian Lance Taylor <i...@google.com>
>
> * diagnostic.c: Include "demangle.h" and "backtrace.h".
> (bt_stop): New static array.
> (bt_callback, bt_err_callback): New static functions.
> (diagnostic_action_after_output): Call backtrace_full for DK_ICE.
> * Makefile.in (BACKTRACE): New variable.
> (BACKTRACEINC, LIBBACKTRACE): New variables.
> (BACKTRACE_H): New variable.
> (LIBDEPS, LIBS): Add $(LIBBACKTRACE).
> (INCLUDES): Add $(BACKTRACEINC).
> (diagnostic.o): Depend upon $(DEMANGLE_H) and $(BACKTRACE_H).
>
> ./:
>
> 2012-09-17 Ian Lance Taylor <i...@google.com>
>
> * Makefile.def: Make all-gcc depend on all-libbacktrace.
> * Makefile.in: Rebuild.
>
>
