3.3 PATCH: Support DWARF-2 EH on IRIX 6 O32
Rainer Orth
ro@TechFak.Uni-Bielefeld.DE
Fri Jul 19 12:20:00 GMT 2002
While debugging a large number of C++ EH failures on the
mips-sgi-irix6.[25]o32 configuration with gas 2.12.1 and stabs-in-mdebug
debug information, I noticed that I see almost no information on the
affected routines in libstdc++.so and libgcc_s.so, so stabs support in gdb
5.2 seems to suffer from severe bitrot (or intrinsic limitations of the
format). To get a handle on what's going on, I decided to try switching to
DWARF-2 debugging. Trying to use gas 2.12.1 initially, bootstrap failed
since that version generates invalid object files (with sections completely
beyond the end of the object file, something the IRIX 6 O32 ld correctly
chokes on). Switching to gas 2.12.90 allowed me to bootstrap with DWARF-2
debugging the default (by configuring with --without-stabs to override the
default provided by the toplevel configure.in) and find the cause of the
observed EH failures: the configuration didn't include crt{begin, end}.o,
thus __register_frame_info wasn't called and unwind-dw2-fde.c
unseen_objects and seen_objects in unwind-dw2-fde.c remained uninitialized,
so _Unwind_Find_FDE returned NULL, causing __cxa_throw to fail and crash
the program.
Fixing this (and a follow-up patch to handle the new -mdebug switch in gas
2.12.90) gave me testsuite results for this configuration with only 10
additional failures compared to the mips-sgi-irix6.2 (i.e. N32 ABI)
results. I'll post an analysis (and hopefully fixes) of those failures
when I return from vacation in three weeks.
The following trivial patch implements this:
* It makes DWARF-2 debugging the default for the mips-sgi-irix5 and
mips-sgi-irix6*o32 configurations with gas (this is currently overridden
as described above).
* It builds and includes crt{begin, end}.o for the gas configurations only.
Since the IRIX 6 O32 as doesn't handle named sections (despite being an
ELF assembler, it's mainly a port of the old IRIX 5 one), this must not
be turned on when as is in use.
Bootstrapped successfully on mips-sgi-irix6.5o32.
Ok for mainline?
Rainer
Wed Jul 17 20:41:46 2002 Rainer Orth <ro@TechFak.Uni-Bielefeld.DE>
* config/mips/iris5gas.h (DWARF2_DEBUGGING_INFO): Define.
(PREFERRED_DEBUGGING_TYPE): Use DWARF2_DEBUG.
(LINK_SPEC): Define.
(STARTFILE_SPEC): Define.
(ENDFILE_SPEC): Define.
* config/mips/iris6-o32.h (LINK_SPEC): Move ...
* config/mips/iris6-o32-as.h (LINK_SPEC): ... here.
* config/mips/iris6-o32-gas.h: New file.
* config.gcc (mips-sgi-irix6*o32): Use it.
* config/mips/t-iris5-gas: New file.
* config.gcc (mips-sgi-irix6*o32, mips-sgi-irix5*): Use it.
Index: gcc/config.gcc
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config.gcc,v
retrieving revision 1.224
diff -u -p -r1.224 config.gcc
--- gcc/config.gcc 14 Jul 2002 07:01:35 -0000 1.224
+++ gcc/config.gcc 19 Jul 2002 17:03:37 -0000
@@ -1748,11 +1748,12 @@ mcore-*-pe*)
mips-sgi-irix6*o32) # SGI System V.4., IRIX 6, O32 ABI
if test x$gas = xyes
then
- tm_file="mips/iris5.h mips/iris5gas.h"
+ tm_file="mips/iris5.h mips/iris5gas.h mips/iris6-o32-gas.h"
if test x$stabs = xyes
then
tm_file="${tm_file} dbx.h"
fi
+ tmake_file=mips/t-iris5-gas
else
tm_file="mips/iris5.h mips/iris6-o32-as.h"
tmake_file=mips/t-iris5-as
@@ -1826,6 +1827,7 @@ mips-sgi-irix5*) # SGI System V.4., IRI
then
tm_file="${tm_file} dbx.h"
fi
+ tmake_file=mips/t-iris5-gas
else
tm_file=mips/iris5.h
tmake_file=mips/t-iris5-as
Index: gcc/config/mips/iris5gas.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/mips/iris5gas.h,v
retrieving revision 1.8
diff -u -p -r1.8 iris5gas.h
--- gcc/config/mips/iris5gas.h 11 Jul 2002 18:56:56 -0000 1.8
+++ gcc/config/mips/iris5gas.h 19 Jul 2002 17:03:45 -0000
@@ -2,13 +2,43 @@
/* Enable debugging. */
#define DBX_DEBUGGING_INFO
+#define DWARF2_DEBUGGING_INFO
#define SDB_DEBUGGING_INFO
#define MIPS_DEBUGGING_INFO
-#define PREFERRED_DEBUGGING_TYPE SDB_DEBUG
+#define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
/* GNU as does handle DWARF2 directives. */
#undef DWARF2_UNWIND_INFO
#define DWARF2_UNWIND_INFO 1
+
+/* Override iris5.h version to invoke [cd]tors and register eh frame
+ information. */
+#undef LINK_SPEC
+#define LINK_SPEC "\
+%{G*} %{EB} %{EL} %{mips1} %{mips2} %{mips3} \
+%{bestGnum} %{shared} %{non_shared} \
+%{call_shared} %{no_archive} %{exact_version} \
+%{static: -non_shared} \
+%{!static: \
+ %{!shared:%{!non_shared:%{!call_shared: -call_shared -no_unresolved}}}} \
+%{rpath} -init __do_global_ctors -fini __do_global_dtors \
+%{shared:-hidden_symbol __do_global_ctors,__do_global_ctors_1,__do_global_dtors} \
+-_SYSTYPE_SVR4"
+
+/* Override iris5.h versions to include crtbegin.o and crtend.o. */
+
+#undef STARTFILE_SPEC
+#define STARTFILE_SPEC "\
+%{!static: \
+ %{!shared:%{pg:gcrt1.o%s}%{!pg:%{p:mcrt1.o%s libprof1.a%s}%{!p:crt1.o%s}}}} \
+%{static: \
+ %{pg:gcrt1.o%s} \
+ %{!pg:%{p:/usr/lib/nonshared/mcrt1.o%s libprof1.a%s} \
+ %{!p:/usr/lib/nonshared/crt1.o%s}}} \
+crtbegin.o%s"
+
+#undef ENDFILE_SPEC
+#define ENDFILE_SPEC "crtend.o%s %{!shared:crtn.o%s}"
/* Irix 5 does not have some strange restrictions that Irix 3 had. */
#undef SET_FILE_NUMBER
Index: gcc/config/mips/iris6-o32-as.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/mips/iris6-o32-as.h,v
retrieving revision 1.1
diff -u -p -r1.1 iris6-o32-as.h
--- gcc/config/mips/iris6-o32-as.h 11 Jul 2002 18:56:56 -0000 1.1
+++ gcc/config/mips/iris6-o32-as.h 19 Jul 2002 17:03:45 -0000
@@ -11,3 +11,19 @@
#define SUBTARGET_ASM_OPTIMIZING_SPEC "\
%{noasmopt:-O0} \
%{!noasmopt:%{O|O1|O2|O3:-O2}}"
+
+/* Enforce use of O32 linker, irrespective of SGI_ABI environment variable
+ and machine type (e.g., R8000 systems default to -64). Copied from
+ iris5.h, only adding -32. The default options -call_shared -no_unresolved
+ are only passed if not invoked with -r. */
+#undef LINK_SPEC
+#define LINK_SPEC "\
+%{G*} %{EB} %{EL} %{mips1} %{mips2} %{mips3} \
+%{bestGnum} %{shared} %{non_shared} \
+%{call_shared} %{no_archive} %{exact_version} \
+%{static: -non_shared} \
+%{!static: \
+ %{!shared:%{!non_shared:%{!call_shared:%{!r: -call_shared -no_unresolved}}}}} \
+%{rpath} \
+-_SYSTYPE_SVR4 \
+-32"
Index: gcc/config/mips/iris6-o32-gas.h
===================================================================
RCS file: gcc/config/mips/iris6-o32-gas.h
diff -N gcc/config/mips/iris6-o32-gas.h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ gcc/config/mips/iris6-o32-gas.h 19 Jul 2002 17:03:45 -0000
@@ -0,0 +1,19 @@
+/* Definitions of target machine for GNU compiler, for MIPS running IRIX 6
+ (O32 ABI) using the GNU assembler. */
+
+/* Enforce use of O32 linker, irrespective of SGI_ABI environment variable
+ and machine type (e.g., R8000 systems default to -64). Copied from
+ iris5gas.h, only adding -32. The default options -call_shared
+ -no_unresolved are only passed if not invoked with -r. */
+#undef LINK_SPEC
+#define LINK_SPEC "\
+%{G*} %{EB} %{EL} %{mips1} %{mips2} %{mips3} \
+%{bestGnum} %{shared} %{non_shared} \
+%{call_shared} %{no_archive} %{exact_version} \
+%{static: -non_shared} \
+%{!static: \
+ %{!shared:%{!non_shared:%{!call_shared:%{!r: -call_shared -no_unresolved}}}}} \
+%{rpath} -init __do_global_ctors -fini __do_global_dtors \
+%{shared:-hidden_symbol __do_global_ctors,__do_global_ctors_1,__do_global_dtors} \
+-_SYSTYPE_SVR4 \
+-32"
Index: gcc/config/mips/iris6-o32.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/mips/iris6-o32.h,v
retrieving revision 1.1
diff -u -p -r1.1 iris6-o32.h
--- gcc/config/mips/iris6-o32.h 11 Jul 2002 18:56:56 -0000 1.1
+++ gcc/config/mips/iris6-o32.h 19 Jul 2002 17:03:45 -0000
@@ -66,19 +66,3 @@
to -mips1 if no ISA is specified. */
#undef SUBTARGET_ASM_SPEC
#define SUBTARGET_ASM_SPEC "-32 %{!mips*:-mips2}"
-
-/* Enforce use of O32 linker, irrespective of SGI_ABI environment variable
- and machine type (e.g., R8000 systems default to -64). Copied from
- iris5.h, only adding -32. The default options -call_shared -no_unresolved
- are only passed if not invoked with -r. */
-#undef LINK_SPEC
-#define LINK_SPEC "\
-%{G*} %{EB} %{EL} %{mips1} %{mips2} %{mips3} \
-%{bestGnum} %{shared} %{non_shared} \
-%{call_shared} %{no_archive} %{exact_version} \
-%{static: -non_shared} \
-%{!static: \
- %{!shared:%{!non_shared:%{!call_shared:%{!r: -call_shared -no_unresolved}}}}} \
-%{rpath} \
--_SYSTYPE_SVR4 \
--32"
Index: gcc/config/mips/t-iris5-gas
===================================================================
RCS file: gcc/config/mips/t-iris5-gas
diff -N gcc/config/mips/t-iris5-gas
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ gcc/config/mips/t-iris5-gas 19 Jul 2002 17:03:47 -0000
@@ -0,0 +1,5 @@
+# For svr4 we build crtbegin.o and crtend.o which serve to add begin and
+# end labels to the .ctors and .dtors section when we link using gcc.
+
+EXTRA_MULTILIB_PARTS=crtbegin.o crtend.o
+CRTSTUFF_T_CFLAGS=-g1
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