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?
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.
Index: gcc/diagnostic.c
===================================================================
--- gcc/diagnostic.c (revision 191393)
+++ gcc/diagnostic.c (working copy)
@@ -27,8 +27,10 @@ along with GCC; see the file COPYING3.
#include "system.h"
#include "coretypes.h"
#include "version.h"
+#include "demangle.h"
#include "input.h"
#include "intl.h"
+#include "backtrace.h"
#include "diagnostic.h"
#define pedantic_warning_kind(DC) \
@@ -296,6 +298,93 @@ diagnostic_show_locus (diagnostic_contex
pp_set_prefix (context->printer, saved_prefix);
}
+/* Functions at which to stop the backtrace print. It's not
+ particularly helpful to print the callers of these functions. */
+
+static const char * const bt_stop[] =
+{
+ "main",
+ "toplev_main",
+ "execute_one_pass",
+ "compile_file",
+};
+
+/* A callback function passed to the backtrace_full function. */
+
+static int
+bt_callback (void *data, uintptr_t pc, const char *filename, int lineno,
+ const char *function)
+{
+ int *pcount = (int *) data;
+
+ /* If we don't have any useful information, don't print
+ anything. */
+ if (filename == NULL && function == NULL)
+ return 0;
+
+ /* Print up to 20 functions. We could make this a --param, but
+ since this is only for debugging just use a constant for now. */
+ if (*pcount >= 20)
+ {
+ /* Returning a non-zero value stops the backtrace. */
+ return 1;
+ }
+ ++*pcount;
+
+ char *alc = NULL;
+ if (function != NULL)
+ {
+ char *str = cplus_demangle_v3 (function,
+ (DMGL_VERBOSE | DMGL_ANSI
+ | DMGL_GNU_V3 | DMGL_PARAMS));
+ if (str != NULL)
+ {
+ alc = str;
+ function = str;
+ }
+
+ for (size_t i = 0; i < ARRAY_SIZE (bt_stop); ++i)
+ {
+ size_t len = strlen (bt_stop[i]);
+ if (strncmp (function, bt_stop[i], len) == 0
+ && (function[len] == '\0' || function[len] == '('))
+ {
+ if (alc != NULL)
+ free (alc);
+ /* Returning a non-zero value stops the backtrace. */
+ return 1;
+ }
+ }
+ }
+
+ fprintf (stderr, "0x%lx %s\n\t%s:%d\n",
+ pc,
+ function == NULL ? "???" : function,
+ filename == NULL ? "???" : filename,
+ lineno);
+
+ if (alc != NULL)
+ free (alc);
+
+ return 0;
+}
+
+/* A callback function passed to the backtrace_full function. This is
+ called if backtrace_full has an error. */
+
+static void
+bt_err_callback (void *data ATTRIBUTE_UNUSED, const char *msg, int errnum)
+{
+ if (errnum < 0)
+ {
+ /* This means that no debug info was available. Just quietly
+ skip printing backtrace info. */
+ return;
+ }
+ fprintf (stderr, "%s%s%s\n", msg, errnum == 0 ? "" : ": ",
+ errnum == 0 ? "" : xstrerror (errnum));
+}
+
/* Take any action which is expected to happen after the diagnostic
is written out. This function does not always return. */
static void
@@ -334,6 +423,17 @@ diagnostic_action_after_output (diagnost
break;
case DK_ICE:
+ {
+ struct backtrace_state *state =
+ backtrace_create_state (NULL, 0, bt_err_callback, NULL);
+ if (state != NULL)
+ {
+ int count = 0;
+ backtrace_full (state, 2, bt_callback, bt_err_callback,
+ (void *) &count);
+ }
+ }
+
if (context->abort_on_error)
real_abort ();
Index: gcc/Makefile.in
===================================================================
--- gcc/Makefile.in (revision 191393)
+++ gcc/Makefile.in (working copy)
@@ -346,6 +346,11 @@ DECNUMFMT = $(srcdir)/../libdecnumber/$(
DECNUMINC = -I$(DECNUM) -I$(DECNUMFMT) -I../libdecnumber
LIBDECNUMBER = ../libdecnumber/libdecnumber.a
+# The backtrace library.
+BACKTRACE = $(srcdir)/../libbacktrace
+BACKTRACEINC = -I$(BACKTRACE)
+LIBBACKTRACE = ../libbacktrace/.libs/libbacktrace.a
+
# Target to use when installing include directory. Either
# install-headers-tar, install-headers-cpio or install-headers-cp.
INSTALL_HEADERS_DIR = @build_install_headers_dir@
@@ -905,6 +910,7 @@ OPTS_H = $(INPUT_H) $(VEC_H) opts.h
DECNUM_H = $(DECNUM)/decContext.h $(DECNUM)/decDPD.h $(DECNUM)/decNumber.h \
$(DECNUMFMT)/decimal32.h $(DECNUMFMT)/decimal64.h \
$(DECNUMFMT)/decimal128.h $(DECNUMFMT)/decimal128Local.h
+BACKTRACE_H = $(BACKTRACE)/backtrace.h
MKDEPS_H = $(srcdir)/../libcpp/include/mkdeps.h
SYMTAB_H = $(srcdir)/../libcpp/include/symtab.h $(OBSTACK_H)
CPP_ID_DATA_H = $(CPPLIB_H) $(srcdir)/../libcpp/include/cpp-id-data.h
@@ -987,7 +993,7 @@ BUILD_LIBIBERTY = $(build_libobjdir)/lib
# Dependencies on the intl and portability libraries.
LIBDEPS= libcommon.a $(CPPLIB) $(LIBIBERTY) $(LIBINTL_DEP) $(LIBICONV_DEP) \
- $(LIBDECNUMBER)
+ $(LIBDECNUMBER) $(LIBBACKTRACE)
# Likewise, for use in the tools that must run on this machine
# even if we are cross-building GCC.
@@ -995,8 +1001,8 @@ BUILD_LIBDEPS= $(BUILD_LIBIBERTY)
# How to link with both our special library facilities
# and the system's installed libraries.
-LIBS = @LIBS@ libcommon.a $(CPPLIB) $(LIBINTL) $(LIBICONV) $(LIBIBERTY) \
- $(LIBDECNUMBER) $(HOST_LIBS)
+LIBS = @LIBS@ libcommon.a $(CPPLIB) $(LIBINTL) $(LIBICONV) $(LIBBACKTRACE) \
+ $(LIBIBERTY) $(LIBDECNUMBER) $(HOST_LIBS)
BACKENDLIBS = $(CLOOGLIBS) $(GMPLIBS) $(PLUGINLIBS) $(HOST_LIBS) \
$(ZLIB)
# Any system libraries needed just for GNAT.
@@ -1028,7 +1034,7 @@ BUILD_ERRORS = build/errors.o
# libintl.h will be found in ../intl if we are using the included libintl.
INCLUDES = -I. -I$(@D) -I$(srcdir) -I$(srcdir)/$(@D) \
-I$(srcdir)/../include @INCINTL@ \
- $(CPPINC) $(GMPINC) $(DECNUMINC) \
+ $(CPPINC) $(GMPINC) $(DECNUMINC) $(BACKTRACEINC) \
$(CLOOGINC) $(ISLINC)
.c.o:
@@ -2613,7 +2619,8 @@ fold-const.o : fold-const.c $(CONFIG_H)
$(GGC_H) $(TM_P_H) langhooks.h $(MD5_H) intl.h $(TARGET_H) \
$(GIMPLE_H) realmpfr.h $(TREE_FLOW_H)
diagnostic.o : diagnostic.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
- version.h $(INPUT_H) intl.h $(DIAGNOSTIC_H) diagnostic.def
+ version.h $(DEMANGLE_H) $(INPUT_H) intl.h $(BACKTRACE_H) $(DIAGNOSTIC_H) \
+ diagnostic.def
opts.o : opts.c $(OPTS_H) $(OPTIONS_H) $(DIAGNOSTIC_CORE_H) $(CONFIG_H) $(SYSTEM_H) \
coretypes.h $(TM_H) \
$(DIAGNOSTIC_H) insn-attr-common.h intl.h $(COMMON_TARGET_H) \
Index: Makefile.def
===================================================================
--- Makefile.def (revision 191397)
+++ Makefile.def (working copy)
@@ -305,6 +305,7 @@ dependencies = { module=all-gcc; on=all-
dependencies = { module=all-gcc; on=all-build-libiberty; };
dependencies = { module=all-gcc; on=all-build-fixincludes; };
dependencies = { module=all-gcc; on=all-zlib; };
+dependencies = { module=all-gcc; on=all-libbacktrace; hard=true; };
dependencies = { module=all-gcc; on=all-libcpp; hard=true; };
dependencies = { module=all-gcc; on=all-libdecnumber; hard=true; };
dependencies = { module=all-gcc; on=all-libiberty; };
