Add R_X86_64_converted_reloc_bit to relocation type to indicate if a
relocation is converted from a GOTPCREL relocation. Linker now generates
failed to convert GOTPCREL relocation; relink with --no-relax
for all cases, including relocations against local symbols.
bfd/
* elf64-x86-64.c (R_X86_64_converted_reloc_bit): New.
(elf_x86_64_info_to_howto): Get the real relocation type by
masking out R_X86_64_converted_reloc_bit.
(elf_x86_64_check_tls_transition): Get the real relocation type
by masking out R_X86_64_converted_reloc_bit.
(elf_x86_64_convert_load_reloc): Set R_X86_64_converted_reloc_bit
instead of setting converted_reloc.
(elf_x86_64_relocate_section): Check R_X86_64_converted_reloc_bit
instead of converted_reloc. Get the real relocation type by
masking out R_X86_64_converted_reloc_bit.
(elf_x86_64_link_setup_gnu_properties): Verify that the value of
R_X86_64_converted_reloc_bit is valid.
* elfxx-x86.h (converted_reloc): Removed.
ld/
* testsuite/ld-x86-64/pr19609-2a.d: Updated.
* testsuite/ld-x86-64/pr19609-2b.d: Likewise.
* testsuite/ld-x86-64/pr19609-4a.d: Likewise.
* testsuite/ld-x86-64/pr19609-4c.d: Likewise.
Don't change r_type when performing TLS transitions to avoid getting
the relocation type with ELF32_R_TYPE again.
* elf32-i386.c (elf_i386_relocate_section): Don't change r_type
when calling elf_i386_tls_transition. Don't use ELF32_R_TYPE
to get the relocation type again.
* elf64-x86-64.c (elf_x86_64_relocate_section): Don't change
r_type when calling elf_x86_64_tls_transition. Don't use
ELF32_R_TYPE to get the relocation type again.
Since 2273f0ac95 ("change minsyms not to be relocated at
read-time"), printing TLS symbols of objfiles with a non-zero base
address, without debug info, fails.
E.g., with:
$ mv /usr/lib/debug /usr/lib/debug-x
to get debug info out of the way, we get:
$ echo 'int main(){}' | gcc -pthread -x c -
$ ./gdb -q -ex start -ex 'p (int) errno' ./a.out
Cannot access memory at address 0xffffef7c0698
instead of the expected:
$1 = 0
The regression is not visible with glibc debuginfo installed.
The problem is that we compute the address of TLS minsyms incorrectly.
To trigger the problem, it is important that the variable is in an
objfile with a non-zero base address. While glibc is a shared library
for 'errno', it's easier for the testcase to use PIE instead of a
shlib. For TLS variables in PT_EXEC the regression obviously does not
happen.
gdb/ChangeLog
2017-09-06 Jan Kratochvil <jan.kratochvil@redhat.com>
* parse.c (find_minsym_type_and_address): Don't relocate addresses
of TLS symbols.
gdb/testsuite/ChangeLog
2017-09-06 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.threads/tls-nodebug-pie.c: New file.
* gdb.threads/tls-nodebug-pie.exp: New file.
commit 23732b1e32
Author: Pedro Alves <palves@redhat.com>
Date: Tue Jun 27 16:22:08 2017 +0100
changed objfile_per_bfd_storage->storage_obstack
from 'struct obstack storage_obstack;'
to 'auto_obstack storage_obstack;'
So the obstack is auto allocated when the objfile_per_bfd_storage ctor is
manually called by get_objfile_bfd_data).
However, the ctor call was still followed by a manual call to
obstack_init (&storage->storage_obstack);
This results in a bunch of leaks detected by valgrind, such as:
==24665== 4,064 bytes in 1 blocks are definitely lost in loss record 11,469 of 11,590
==24665== at 0x4C27BF5: malloc (vg_replace_malloc.c:299)
==24665== by 0x5437B7: xmalloc (common-utils.c:44)
==24665== by 0x77CAA7: _obstack_begin_worker (obstack.c:141)
==24665== by 0x60168F: auto_obstack (gdb_obstack.h:70)
==24665== by 0x60168F: get_objfile_bfd_data(objfile*, bfd*) (objfiles.h:188)
==24665== by 0x601DB6: allocate_objfile(bfd*, char const*, enum_flags<objfile_flag>) (objfiles.c:423)
==24665== by 0x647753: symbol_file_add_with_addrs(bfd*, char const*, enum_flags<symfile_add_flag>, section_addr_info*, enum_flags<objfile_flag>, objfile*) (symfile.c:1158)
==24665== by 0x647C7B: symbol_file_add_separate(bfd*, char const*, enum_flags<symfile_add_flag>, objfile*) (symfile.c:1252)
==24665== by 0x4C7D79: elf_symfile_read(objfile*, enum_flags<symfile_add_flag>) (elfread.c:1270)
==24665== by 0x647CB4: read_symbols(objfile*, enum_flags<symfile_add_flag>) (symfile.c:861)
==24665== by 0x647809: syms_from_objfile_1 (symfile.c:1062)
-> remove the manual call to obstack_init.
Reg-tested on Debian 8/amd64, tests results are the same before/after the patch.
valgrind still show some leaks, but less.
gdb/ChangeLog
2017-09-05 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* objfiles.c (get_objfile_bfd_data): Remove useless obstack_init
call.
When GOTPCREL relocation conversion leads to relocation overflow, we
may get a mysterious linker message, like
relocation truncated to fit: R_X86_64_32S against symbol `foo'
This patch changes the linker message to
failed to convert GOTPCREL relocation; relink with --no-relax
bfd/
* elf64-x86-64.c (elf_x86_64_convert_load_reloc): Remove the sec
argument. Don't check relocation overflow. Avoid relocation
overflow if --no-relax is used. Set converted_reloc on symbol
if a GOTPCREL relocation is converted.
(elf_x86_64_relocate_section): Issue a fatal error and suggest
--no-relax if GOTPCREL relocation conversion leads to relocation
overflow.
* elfxx-x86.h (elf_x86_link_hash_entry): Add converted_reloc.
ld/
* testsuite/ld-x86-64/pr19609-4e.d: Updated.
* testsuite/ld-x86-64/pr19609-6a.d: Likewise.
I noticed that the gdb.rust tests fail because the test suite passes
-fdiagnostics-color=never to rustc. This is not a recognized rustc
option, and the test suite already handles passing the appropriate
option to the Rust compiler.
This patch fixes the problem.
testsuite/ChangeLog
2017-09-05 Tom Tromey <tom@tromey.com>
* lib/gdb.exp (gdb_compile): Don't use universal_compile_options
for rust.
Using follow-exec-mode "new" takes a different code path than "same", so
it's interesting to test this path in combination with a change in
architecture of the inferior. This test fails if you remove the
previous patch.
gdb/testsuite/ChangeLog:
* gdb.multi/multi-arch-exec.exp: Test with different
"follow-exec-mode" settings.
(do_test): New procedure.
As mentioned in the previous patch, we should avoid doing register reads
after a process does an exec and before we've updated that inferior's
gdbarch. Otherwise, we may interpret the registers using the wrong
architecture. When a process does an exec with "follow-exec-mode new",
a new inferior is added by follow_exec. The gdbarch of that new
inferior is at first set to some default value, probably specific to the
gdb build (I get "i386" here), which may not be the right one. It is
updated later by the call to target_find_description. Before that
point, if we try to read the inferior's registers, we may not interpret
them correctly. This has been exposed by a failure in
gdb.base/foll-exec-mode.exp after the previous patch, with:
Remote 'g' packet reply is too long (expected 312 bytes, got 816 bytes)
The call to "add_thread" done just after adding the inferior is
problematic, because it ends up reading the registers (because the ptid
is re-used, we end up doing a switch_to_thread to it, which tries to
update stop_pc). The registers returned by gdbserver are the x86-64
ones, while we try to interpret them using the "i386" gdbarch.
Postponing the call to add_thread to until the target
description/gdbarch has been updated seems to fix the issue.
As to why this issue was uncovered by the previous patch: what I think
happened before that patch is that since we were updating stop_pc before
switching to the new inferior, we were filling the regcache associated
to the ptid (this worked fine as long as the architectures of the
previous and new process images were the same). The call to
switch_to_thread then worked, because the register read hit the
regcache. Now, it triggers a register read, while the gdbarch is not
set correctly, leading to the "reply is too long" error. If this is
right, it sounds wrong that we delete and re-add a thread with the same
ptid, and are able to access the registers from the deleted thread.
When we delete a thread, should we clear the regcache associated to that
ptid, so that the new thread starts with a fresh/empty regcache?
gdb/ChangeLog:
* infrun.c (follow_exec): Call add_thread after
target_find_description.
When an inferior execs and changes architecture (e.g. 64 bits to 32
bits), the gdbarch associated to the inferior is updated by the
follow_exec call in handle_inferior_event_1. We should avoid doing any
register read before that point, because the registers sent by the
remote side will be those of the new architecture, but we would
interpret them using the old architecture. We do just that by setting
stop_pc during this window, which obviously requires reading the
registers. This results in gdb.multi/multi-arch-exec.exp failing, GDB
outputting the following error:
Truncated register 50 in remote 'g' packet
This patch fixes that by postponing the setting of stop_pc to after
we've updated the inferior gdbarch.
This bug was hiding another problem, and as such introduces some
failures in gdb.base/foll-exec-mode.exp. The following patch takes care
of that.
gdb/ChangeLog:
* infrun.c (handle_inferior_event_1): When exec'ing, read
stop_pc after follow_exec.
... by adding the expected size, and the received size. I found this
useful when debugging gdbarch/remote issues, since it gives a hint of
what gdb expects and what the remote sent.
gdb/ChangeLog:
* remote.c (process_g_packet): Update error message.
This patch fixes the build failure caused by 22916b0
(Convert the rest x86 target descriptions).
gdb:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* configure.tgt (gdb_target_obs): Add i386.o for x86_64-*
targets.
While working on the no-debug-info debugging improvements, I found
evaluate_subexp_standard's function call code unnecessarily long and
hard to navigate and debug. The use of goto doesn't help either.
This commit tries to improve things by factoring out the
function-call-related code to separate helper functions.
gdb/ChangeLog:
2017-09-05 Pedro Alves <palves@redhat.com>
* eval.c (eval_call, evaluate_funcall): New functions, factored
out from ...
(evaluate_subexp_standard): ... this.
GDBserver now is able to generate target descriptions from features, so
don't need to remember these target description files.
Note that it should be i386/amd64-avx-avx512-linux.xml instead of
i386/amd64-avx-avx512.xml in $srv_amd64_linux_xmlfiles. This patch
removes it anyway.
gdb/gdbserver:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* configure.srv (srv_amd64_linux_xmlfiles): Remove
i386/amd64-XXX-linux from it.
Now, all these amd64-linux pre-generated tdesc can be used as test, so
don't need to build them if $development is false.
gdb/gdbserver:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* configure.srv: Empty srv_amd64_linux_regobj if $development is
false.
(ipa_amd64_linux_regobj): Remove.
(ipa_x32_linux_regobj): Remove.
This patch changes amd64-linux target descriptions so that they can be
dynamically generated in both GDB and GDBserver.
gdb/gdbserver:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* Makefile.in (arch-amd64.o): New rule.
* configure.srv: Append arch-amd64.o.
* linux-amd64-ipa.c: Include common/x86-xstate.h.
(get_ipa_tdesc): Call amd64_linux_read_description.
(initialize_low_tracepoint): Don't call init_registers_x32_XXX
and init_registers_amd64_XXX.
* linux-x86-low.c (x86_linux_read_description): Call
amd64_linux_read_description.
(x86_get_ipa_tdesc_idx): Call amd64_get_ipa_tdesc_idx.
(initialize_low_arch): Don't call init_registers_x32_XXX and
init_registers_amd64_XXX.
* linux-x86-tdesc-selftest.c: Declare init_registers_amd64_XXX
and tdesc_amd64_XXX.
[__x86_64__] (amd64_tdesc_test): New function.
(initialize_low_tdesc) [__x86_64__]: Call init_registers_x32_XXX
and init_registers_amd64_XXX.
* linux-x86-tdesc.c: Include arch/amd64.h.
(xcr0_to_tdesc_idx): New function.
(i386_linux_read_description): New function.
(amd64_get_ipa_tdesc_idx): New function.
* linux-x86-tdesc.h (amd64_get_ipa_tdesc_idx): Declare.
(amd64_get_ipa_tdesc): Declare.
gdb:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* amd64-linux-tdep.c: Include arch/amd64.h. Don't include
features/i386/*.c.
(amd64_linux_read_description): Call
amd64_create_target_description.
* arch/amd64.c: New file.
* arch/amd64.h: New file.
* configure.tgt (x86_64-*-linux*): Append amd64.o.
* Makefile.in (ALL_64_TARGET_OBS): Append amd64.o.
This patch adds a new function amd64_linux_read_description, which
creates amd64-linux target descriptions according to its two
arguments, xcr0 and is_x32.
gdb:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* amd64-linux-tdep.c (amd64_linux_read_description): New
function.
(amd64_linux_core_read_description): Call
amd64_linux_read_description.
(amd64_linux_init_abi): Likewise.
(amd64_x32_linux_init_abi): Likewise.
* amd64-linux-tdep.h (amd64_linux_read_description): Declare.
* x86-linux-nat.c (x86_linux_read_description): Call
amd64_linux_read_description.
GDBserver now is able to generate target descriptions from features, so
don't need to remember these target description files.
gdb/gdbserver:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* configure.srv (srv_i386_linux_xmlfiles): Remove
i386/i386-XXX-linux.xml from it.
Now, these *-generate.c files are only used in GDBserver for unit test.
If $development is false (in release), these *-generate.c files won't be
used at all.
gdb/gdbserver:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* configure.srv: Set srv_i386_linux_regobj empty if $development
is false.
* linux-i386-ipa.c (initialize_low_tracepoint): Don't call
initialize_low_tdesc.
* linux-x86-low.c (initialize_low_arch): Wrap initialize_low_tdesc
with #if initialize_low_tdesc.
* linux-x86-tdesc-selftest.c: New file.
* linux-x86-tdesc.c: Move code to linux-x86-tdesc-selftest.c.
The code on creating i386-linux target descriptions are quite similar
between GDB and GDBserver, so this patch moves them into a shared file
arch/i386.c. I didn't name it as i386-linux.c, because I want to reuse it
to create other i386 non-linux target descriptions later.
gdb:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* Makefile.in (ALL_TARGET_OBS): Add i386.o.
(SFILES): Add arch/i386.c.
(HFILES_NO_SRCDIR): Add arch/i386.h.
* arch/i386.c: New file.
* arch/i386.h: New file.
* arch/tdesc.h (allocate_target_description): Declare.
(set_tdesc_architecture): Declare.
(set_tdesc_osabi): Declare.
* configure.tgt (i[34567]86-*-linux*): Add i386.o.
* i386-linux-tdep.c: Don't include ../features/i386/32bit-XXX.c.
include arch/i386.h.
(i386_linux_read_description): Remove code and call
i386_create_target_description.
(set_tdesc_architecture): New function.
(set_tdesc_osabi): New function.
* target-descriptions.h (allocate_target_description): Remove.
gdb/gdbserver:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* Makefile.in (arch-i386.o): New rule.
* configure.srv (i[34567]86-*-linux*): Add arch-i386.o.
(x86_64-*-linux*): Likewise.
* linux-x86-tdesc.c: Don't include ../features/i386/32bit-XXX.c,
include arch/i386.h.
(i386_linux_read_description): Remove code and call
i386_create_target_description.
* tdesc.c (allocate_target_description): New function.
* tdesc.h (set_tdesc_architecture): Remove declaration.
(set_tdesc_osabi): Likewise.
GDBserver still uses pre-generated target descriptions in order to
reply to GDB's query on target description (see xml-builtin-generated.c
in GDBserver build directory). This patch teaches GDBserver to
create XML contents according to the target descriptions rather than
using pre-generated ones.
First, change target feature c files to pass the feature xml file
name to tdesc_create_feature, so that target description in GDBserver
can record them, and create XML contents from these features in
buffer, like
...
<xi:include href="$FEATURE1_XML_NAME"/>
<xi:include href="$FEATURE2_XML_NAME"/>
...
and send this buffer back to GDB.
Note that this patch reuses target_desc.xmltarget a little bit, which is
to hold the XML contents dynamically generated in tdesc_get_features_xml.
However, it is not xfree'ed in ~target_desc, because we can't tell it is
from xstrdup or a literal string. Since we don't delete target_desc,
there is no memory leak yet. After we change all target descriptions to
the new style, target_desc.xmltarget is from xstrdup, then, we can safely
xfree it in ~target_desc.
gdb:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* arch/tdesc.h (tdesc_create_feature): Add an argument xml.
* target-descriptions.c (tdesc_create_feature): Likewise, and
adjust code.
* features/i386/32bit-avx.c: Re-generated.
* features/i386/32bit-avx512.c: Re-generated.
* features/i386/32bit-core.c: Re-generated.
* features/i386/32bit-linux.c: Re-generated.
* features/i386/32bit-mpx.c: Re-generated.
* features/i386/32bit-pkeys.c: Re-generated.
* features/i386/32bit-sse.c: Re-generated.
gdb/gdbserver:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* linux-x86-tdesc.c: Don't include <inttypes.h>.
(i386_linux_read_description) [!IN_PROCESS_AGENT]: Call
set_tdesc_architecture and set_tdesc_osabi. Remove code setting
.xmltarget.
* server.c (get_features_xml): Call tdesc_get_features_xml.
* tdesc.c (set_tdesc_architecture): New function.
(set_tdesc_osabi): New function.
(tdesc_get_features_xml): New function.
(tdesc_create_feature): Add an argument.
* tdesc.h (struct target_desc) <features>: New field.
<arch, osabi>: New field.
(~target_desc): xfree features, arch, and osabi.
(target_desc::oerator==): Don't compare .xmltarget.
[!IN_PROCESS_AGENT] (set_tdesc_architecture): Declare.
(set_tdesc_osabi): Likewise.
(tdesc_get_features_xml): Likewise.
This patch adds a unit test in GDBserver to test dynamically created
target descriptions equal these pre-generated ones.
gdb/gdbserver:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* linux-x86-tdesc.c: Include selftest.h.
(i386_tdesc_test): New function.
(initialize_low_tdesc): Call selftests::register_test.
* tdesc.h: Include regdef.h.
(target_desc): Override operator == and !=.
gdb:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* regformats/regdef.h (struct reg): Override operator == and !=.
tdesc_i386_XXX_linux is used in many places in linux-x86-low.c and this
patch adds a new function i386_linux_read_description to return the right
tdesc according to xcr0. i386_linux_read_description is quite similar to
the counterpart in GDB, and the following patch will share the duplicated
code, so this patch adds arch/tdesc.h includes the declarations of various
tdesc apis which are used by the shared code. The generated c feature
files can include arch/tdesc.h only.
gdb/gdbserver:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* configure.srv (srv_tgtobj): Append linux-x86-tdesc.o.
(ipa_obj): Likewise.
* linux-i386-ipa.c: Include common/x86-xstate.h
(get_ipa_tdesc): Call i386_linux_read_description.
(initialize_low_tracepoint): Don't call init_registers_XXX
functions, call initialize_low_tdesc instead.
* linux-x86-low.c (x86_linux_read_description): Call
i386_linux_read_description.
(initialize_low_arch): Don't call init_registers_i386_XXX
functions, call initialize_low_tdesc.
* linux-x86-tdesc.c: New file.
* linux-x86-tdesc.h (x86_linux_tdesc): New X86_TDESC_LAST.
(i386_get_ipa_tdesc_idx): Declare.
(i386_get_ipa_tdesc): Declare.
(initialize_low_tdesc): Declare.
gdb:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* arch/tdesc.h: New file.
* regformats/regdat.sh: Generate code using tdesc_create_reg.
* target-descriptions.c: Update comments.
* target-descriptions.h: Include "arch/tdesc.h". Remove the
declarations.
* features/i386/32bit-avx.c: Re-generated.
* features/i386/32bit-avx512.c: Re-generated.
* features/i386/32bit-core.c: Re-generated.
* features/i386/32bit-linux.c: Re-generated.
* features/i386/32bit-mpx.c: Re-generated.
* features/i386/32bit-pkeys.c: Re-generated.
* features/i386/32bit-sse.c: Re-generated.
Nowadays, target_desc.reg_defs is a pointer points to a pre-generated
array, which is not flexible. This patch changes it from an array
to a VEC so that GDBserver can create target descriptions dynamically
later. Instead of using pre-generated array, the -generated.c calls
VEC_safe_push to add each register to vector.
Since target_desc.reg_defs is used in IPA, we need to build common/vec.c
for IPA too.
gdb/gdbserver:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* Makefile.in (IPA_OBJS): Add vec-ipa.o
* regcache.c (get_thread_regcache): Use VEC_length.
(init_register_cache): Likewise.
(regcache_cpy): Likewise.
(registers_to_string): Iterate reg_defs via VEC_iterate.
(find_regno): Likewise.
(find_register_by_number): Use VEC_index.
(register_size): Call find_register_by_number.
(register_data): Call find_register_by_number.
(supply_regblock): Use VEC_length.
(regcache_raw_read_unsigned): Likewise.
* tdesc.c (init_target_desc): Iterate reg_defs via
VEC_iterate.
(default_description): Update initializer.
(copy_target_description): Don't update field num_registers.
* tdesc.h (struct target_desc) <reg_defs>: Change it to VEC.
<num_registers>: Remove.
gdb:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* regformats/regdat.sh: Update generated code.
regformats/regdat.sh generate some *-generated.c files when GDBserver
is built. Each .c file has some static variables, which are only used
within function init_registers_XXX, like this,
static struct reg regs_i386_linux[] = {
{ "eax", 0, 32 },
{ "ecx", 32, 32 },
...
};
static const char *expedite_regs_i386_linux[] = { "ebp", "esp", "eip", 0 };
static const char *xmltarget_i386_linux = "i386-linux.xml";
void
init_registers_i386_linux (void)
{
...
}
This patch moves these static variables' definitions to function
init_registers_XXX, so the generated files look like this,
void
init_registers_i386_linux (void)
{
static struct target_desc tdesc_i386_linux_s;
struct target_desc *result = &tdesc_i386_linux_s;
static struct reg regs_i386_linux[] = {
...
};
static const char *expedite_regs_i386_linux[] = { "ebp", "esp", "eip", 0 };
static const char *xmltarget_i386_linux = "i386-linux.xml";
...
}
We want GDBserver create target descriptions dynamically in each
init_registers_XXXX functions, so this patch moves all the related code
into function init_registers_XXXX, so that the following patch can easily
change function init_registers_XXXX to create target description
dynamically, rather than using current pre-generated array.
gdb:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* regformats/regdat.sh: Adjust code order.
My compiler (gcc 5.4.0, clang 3.8) gives this warning:
/home/emaisin/src/binutils-gdb/gdb/expprint.c: In lambda function:
/home/emaisin/src/binutils-gdb/gdb/expprint.c:1055:35: error: format not a string literal and no format arguments [-Werror=format-security]
fprintf_filtered (stream, mod);
^
Fix it by not using the passed string as the format string.
gdb/ChangeLog:
* expprint.c (dump_subexp_body_standard): Use constant format
string in fprintf_filtered call.
Previously this used the error function from GDB directly when linked
against GDB instead of the error method in the host callbacks
structure. This was exposed via a link error when GDB was converted
to C++. The error function invokes the error callback similar to
sim_io_error.
Note that there are also error functions in sim/ppc/main.c and
sim/ppc/misc.c. The ppc libsim.a expects each consumer to provide
several symbols used by the library including "error". sim-calls.c
provides these symbols when the library is linked into gdb. The dgen,
igen, tmp-filter, tmp-ld-decode, tmp-ld-cache, and tmp-ld-insn programs
use the functions from misc.c. psim uses the functions from main.c.
sim/ppc/ChangeLog:
PR sim/20863
* sim_calls.c (error): New function.
NetBSD recently added PT_GETDBREGS and PT_SETDBREGS ptrace operations
that match the existing ones supported by x86-bsd-nat.c. NetBSD's
headers do not provide the DBREG_DRX helper macro, so define a local
version in x86-bsd-nat.c. In addition, add the x86-nat.o and x86-dregs.o
object files to the native NetBSD x86 build targets.
gdb/ChangeLog:
* configure.nat: Add "x86-nat.o x86-dregs.o" for NetBSD/amd64 and
NetBSD/i386.
* x86-bsd-nat.c [!DBREG_DRX && __NetBSD__]: Define DBREG_DRX.
Recent versions of NetBSD hide certain kernel structures needed by the
KVM target from userland unless this macro is defined.
gdb/ChangeLog:
* bsd-kvm.o: Define _KMEMUSER.
* configure.ac: Define _KMEMUSER when checking for "struct lwp".
* configure: Regenerate.
Here's the documentation bits for all the improvements done in
previous commits.
Note that the original "weak alias functions" paragraph ends up
disappearing, because this patch, which I'm considering kind of part
of this series, makes the alias case Just Work:
https://sourceware.org/ml/gdb-patches/2017-07/msg00018.html
gdb/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* NEWS (Safer support for debugging with no debug info): New.
gdb/doc/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Variables) <Program Variables>: Document inspecting
no-debug-info variables.
(Symbols) <Examining the Symbol Table>: Document inspecting
no-debug-info types.
(Calling) <Calling functions with no debug info>: New subsection,
documenting calling no-debug-info functions.
(Non-debug DLL Symbols) <Working with Minimal Symbols>: Update.
Trying to print a function local static variable of a const-qualified
method still doesn't work after the previous fixes:
(gdb) p 'S::method() const'::static_var
$1 = {i1 = 1, i2 = 2, i3 = 3}
(gdb) p S::method() const::static_var
No symbol "static_var" in specified context.
The reason is that the expression parser/evaluator loses the "const",
and the above unquoted case is just like trying to print a variable of
the non-const overload, if it exists, even. As if the above unquoted
case had been written as:
(gdb) p S::method()::static_var
No symbol "static_var" in specified context.
We can see the problem without static vars in the picture. With:
struct S
{
void method ();
void method () const;
};
Compare:
(gdb) print 'S::method(void) const'
$1 = {void (const S * const)} 0x400606 <S::method() const>
(gdb) print S::method(void) const
$2 = {void (S * const)} 0x4005d8 <S::method()> # wrong method!
That's what we need to fix. If we fix that, the function local static
case starts working.
The grammar production for function/method types is this one:
exp: exp '(' parameter_typelist ')' const_or_volatile
This results in a TYPE_INSTANCE expression evaluator operator. For
the example above, we get something like this ("set debug expression 1"):
...
0 TYPE_INSTANCE 1 TypeInstance: Type @0x560fda958be0 (void)
5 OP_SCOPE Type @0x560fdaa544d8 (S) Field name: `method'
...
While evaluating TYPE_INSTANCE, we end up in
value_struct_elt_for_reference, trying to find the method named
"method" that has the prototype recorded in TYPE_INSTANCE. In this
case, TYPE_INSTANCE says that we're looking for a method that has
"(void)" as parameters (that's what "1 TypeInstance: Type
@0x560fda958be0 (void)" above means. The trouble is that nowhere in
this mechanism do we communicate to value_struct_elt_for_reference
that we're looking for the _const_ overload.
value_struct_elt_for_reference only compared parameters, and the
non-const "method()" overload has matching parameters, so it's
considered the right match...
Conveniently, the "const_or_volatile" production in the grammar
already records "const" and "volatile" info in the type stack. The
type stack is not used in this code path, but we can borrow the
information. The patch converts the info in the type stack to an
"instance flags" enum, and adds that as another element in
TYPE_INSTANCE operators. This type instance flags is then applied to
the temporary type that is passed to value_struct_elt_for_reference
for matching.
The other side of the problem is that methods in the debug info aren't
marked const/volatile, so with that in place, the matching never finds
const/volatile-qualified methods.
The problem is that in the DWARF, there's no indication at all whether
a method is const/volatile qualified... For example (c++filt applied
to the linkage name for convenience):
<2><d3>: Abbrev Number: 6 (DW_TAG_subprogram)
<d4> DW_AT_external : 1
<d4> DW_AT_name : (indirect string, offset: 0x3df): method
<d8> DW_AT_decl_file : 1
<d9> DW_AT_decl_line : 58
<da> DW_AT_linkage_name: (indirect string, offset: 0x5b2): S::method() const
<de> DW_AT_declaration : 1
<de> DW_AT_object_pointer: <0xe6>
<e2> DW_AT_sibling : <0xec>
I see the same with both GCC and Clang. The patch works around this
by extracting the cv qualification from the "const" and "volatile" in
the demangled name. This will need further tweaking for "&" and
"const &" overloads, but we don't support them in the parser yet,
anyway.
The TYPE_CONST changes were necessary otherwise the comparisons in valops.c:
if (TYPE_CONST (intype) != TYPE_FN_FIELD_CONST (f, j))
continue;
would fail, because when both TYPE_CONST() TYPE_FN_FIELD_CONST() were
true, their values were different.
BTW, I'm recording the const/volatile-ness of methods in the
TYPE_FN_FIELD info because #1 - I'm not sure it's kosher to change the
method's type directly (vs having to call make_cv_type to create a new
type), and #2 it's what stabsread.c does:
...
case 'A': /* Normal functions. */
new_sublist->fn_field.is_const = 0;
new_sublist->fn_field.is_volatile = 0;
(*pp)++;
break;
case 'B': /* `const' member functions. */
new_sublist->fn_field.is_const = 1;
new_sublist->fn_field.is_volatile = 0;
...
After all this, this finally all works:
print S::method(void) const
$1 = {void (const S * const)} 0x400606 <S::method() const>
(gdb) p S::method() const::static_var
$2 = {i1 = 1, i2 = 2, i3 = 3}
gdb/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* c-exp.y (function_method, function_method_void): Add current
instance flags to TYPE_INSTANCE.
* dwarf2read.c (check_modifier): New.
(compute_delayed_physnames): Assert that only C++ adds delayed
physnames. Mark fn_fields as const/volatile depending on
physname.
* eval.c (make_params): New type_instance_flags parameter. Use
it as the new type's instance flags.
(evaluate_subexp_standard) <TYPE_INSTANCE>: Extract the instance
flags element and pass it to make_params.
* expprint.c (print_subexp_standard) <TYPE_INSTANCE>: Handle
instance flags element.
(dump_subexp_body_standard) <TYPE_INSTANCE>: Likewise.
* gdbtypes.h: Include "enum-flags.h".
(type_instance_flags): New enum-flags type.
(TYPE_CONST, TYPE_VOLATILE, TYPE_RESTRICT, TYPE_ATOMIC)
(TYPE_CODE_SPACE, TYPE_DATA_SPACE): Return boolean.
* parse.c (operator_length_standard) <TYPE_INSTANCE>: Adjust.
(follow_type_instance_flags): New function.
(operator_check_standard) <TYPE_INSTANCE>: Adjust.
* parser-defs.h (follow_type_instance_flags): Declare.
* valops.c (value_struct_elt_for_reference): const/volatile must
match too.
gdb/testsuite/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* gdb.base/func-static.c (S::method const, S::method volatile)
(S::method volatile const): New methods.
(c_s, v_s, cv_s): New instances.
(main): Call method() on them.
* gdb.base/func-static.exp (syntax_re, cannot_resolve_re): New variables.
(cannot_resolve): New procedure.
(cxx_scopes_list): Test cv methods. Add print-scope-quote and
print-quote-unquoted columns.
(do_test): Test printing each scope too.
While the previous commit made "p method()::static_var" (no
single-quotes) Just Work, if users (or frontends) try wrapping the
expression with quotes, they'll get:
(gdb) p 'S::method()::static_var'
'S::method()::static_var' has unknown type; cast it to its declared type
even if we _do_ have debug info for that variable. That's better than
the bogus/confusing value what GDB would print before the
stop-assuming-int patch:
(gdb) p 'S::method()::static_var'
$1 = 1
but I think it'd still be nice to make this case Just Work too.
In this case, due to the quoting, the C/C++ parser (c-exp.y)
interprets the whole expression/string as a single symbol name, and we
end up calling lookup_symbol on that name. There's no debug symbol
with that fully-qualified name, but since the compiler gives the
static variable a mangled linkage name exactly like the above, it
appears in the mininal symbols:
$ nm -A local-static | c++filt | grep static_var
local-static:0000000000601040 d S::method()::static_var
... and that's what GDB happens to find/print. This only happens in
C++, note, since for C the compiler uses different linkage names:
local-static-c:0000000000601040 d static_var.1848
So while (in C++, not C) function local static variables are given a
mangled name that demangles to the same syntax that GDB
documents/expects as the way to access function local statics, there's
no global symbol in the debug info with that name at all. The debug
info for a static local variable for a non-inline function looks like
this:
<1><2a1>: Abbrev Number: 19 (DW_TAG_subprogram)
...
<2><2f7>: Abbrev Number: 20 (DW_TAG_variable)
<2f8> DW_AT_name : (indirect string, offset: 0x4e9): static_var
<2fc> DW_AT_decl_file : 1
<2fd> DW_AT_decl_line : 64
<2fe> DW_AT_type : <0x25>
<302> DW_AT_location : 9 byte block: 3 40 10 60 0 0 0 0 0 (DW_OP_addr: 601040)
and for an inline function, it looks like this (linkage name run
through c++filt for convenience):
<2><21b>: Abbrev Number: 16 (DW_TAG_variable)
<21c> DW_AT_name : (indirect string, offset: 0x21a): static_var
<220> DW_AT_decl_file : 1
<221> DW_AT_decl_line : 48
<222> DW_AT_linkage_name: (indirect string, offset: 0x200): S::inline_method()::static_var
<226> DW_AT_type : <0x25>
<22a> DW_AT_external : 1
<22a> DW_AT_location : 9 byte block: 3 a0 10 60 0 0 0 0 0 (DW_OP_addr: 6010a0)
(The inline case makes the variable external so that the linker can
merge the different inlined copies. It seems like GCC never outputs
the linkage name for non-extern globals.)
When we read the DWARF, we record the static_var variable as a regular
variable of the containing function's block. This makes stopping in
the function and printing the variable as usual. The variable just so
happens to have a memory address as location.
So one way to make "p 'S::method()::static_var'" work would be to
record _two_ copies of the symbols for these variables. One in the
function's scope/block, with "static_var" as name, as we currently do,
and another in the static or global blocks (depending on whether the
symbol is external), with a fully-qualified name. I wrote a prototype
patch for that, and it works. For the non-inline case above, since
the debug info doesn't point to the linkage same, that patch built the
physname of the static local variable as the concat of the physname of
the containing function, plus "::", plus the variable's name. We
could make that approach work for C too, though it kind of feels
awkward to record fake symbol names like that in C.
The other approach I tried is to change the C++ symbol lookup routines
instead. This is the approach this commit takes. We can already
lookup up symbol in namespaces and classes, so this feels like a good
fit, and was easy enough. The advantage is that this doesn't require
recording extra symbols.
The test in gdb.cp/m-static.exp that exposed the need for this is
removed, since the same functionality is now covered by
gdb.cp/local-static.exp.
gdb/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* cp-namespace.c (cp_search_static_and_baseclasses): Handle
function/method scopes; lookup the nested name as a function local
static variable.
gdb/testsuite/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* gdb.base/local-static.exp: Also test with
class::method::variable wholly quoted.
* gdb.cp/m-static.exp (class::method::variable): Remove test.
This commit makes "print S::method()::static_var" actually find the
debug symbol for static_var. Currently, you get:
(gdb) print S::method()::static_var
A syntax error in expression, near `'.
Quoting the whole string would seemingly work before the previous
patch that made GDB stop assuming int for no-debug-info variables:
(gdb) p 'S::method()::static_var'
$1 = 1
... except that's incorrect output, because:
(gdb) ptype 'S::method()::static_var'
type = <data variable, no debug info>
The way to make it work correctly currently is by quoting the
function/method part, like this:
(gdb) print 'S::method()'::static_var
$1 = {i1 = 1, i2 = 2, i3 = 3}
(gdb) ptype 'S::method()'::static_var
type = struct aggregate {
int i1;
int i2;
int i3;
}
At least after the "stop assuming int" patch, this is what we
now get:
(gdb) p 'S::method()::static_var'
'S::method()::static_var' has unknown type; cast it to its declared type
(gdb) p (struct aggregate) 'S::method()::static_var'
$1 = {i1 = 1, i2 = 2, i3 = 3}
However, IMO, users shouldn't really have to care about any of this.
GDB should Just Work, without quoting, IMO.
So here's a patch that implements support for that in the C++ parser.
With this patch, you now get:
(gdb) p S::method()::S_M_s_var_aggregate
$1 = {i1 = 1, i2 = 2, i3 = 3}
(gdb) ptype S::method()::S_M_s_var_aggregate
type = struct aggregate {
int i1;
int i2;
int i3;
}
gdb/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
(%type <voidval>): Add function_method.
* c-exp.y (exp): New production for calls with no arguments.
(function_method, function_method_void_or_typelist): New
productions.
(exp): New production for "method()::static_var".
* eval.c (evaluate_subexp_standard): Handle OP_FUNC_STATIC_VAR.
* expprint.c (print_subexp_standard, dump_subexp_body_standard):
Handle OP_FUNC_STATIC_VAR.
* parse.c (operator_length_standard):
Handle OP_FUNC_STATIC_VAR.
* std-operator.def (OP_FUNC_STATIC_VAR): New.
gdb/testsuite/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* gdb.base/local-static.c: New.
* gdb.base/local-static.cc: New.
* gdb.base/local-static.exp: New.
Since minsym references now go via OP_VAR_MSYM_VALUE, UNOP_MEMVAL_TLS
is no longer used anywhere.
gdb/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* eval.c (evaluate_subexp_standard): Remove UNOP_MEMVAL_TLS
handling.
* expprint.c (print_subexp_standard, dump_subexp_body_standard):
Ditto.
* parse.c (operator_length_standard, operator_check_standard):
Ditto.
* std-operator.def (UNOP_MEMVAL_TLS): Delete.
An earlier commit made GDB no longer assume no-debug-info functions
return int. This commit gives the same treatment to variables.
Currently, you can end misled by GDB over output like this:
(gdb) p var
$1 = -1
(gdb) p /x var
$2 = 0xffffffff
until you realize that GDB is assuming that the variable is an "int",
because:
(gdb) ptype var
type = <data variable, no debug info>
You may try to fix it by casting, but that doesn't really help:
(gdb) p /x (unsigned long long) var
$3 = 0xffffffffffffffff # incorrect
^^
That's incorrect output, because the variable was defined like this:
uint64_t var = 0x7fffffffffffffff;
^^
What happened is that with the cast, GDB did an int -> 'unsigned long
long' conversion instead of reinterpreting the variable as the cast-to
type. To get at the variable properly you have to reinterpret the
variable's address manually instead, with either:
(gdb) p /x *(unsigned long long *) &var
$4 = 0x7fffffffffffffff
(gdb) p /x {unsigned long long} &var
$5 = 0x7fffffffffffffff
After this commit GDB does it for you. This is what you'll get
instead:
(gdb) p var
'var' has unknown type; cast it to its declared type
(gdb) p /x (unsigned long long) var
$1 = 0x7fffffffffffffff
As in the functions patch, the "compile" machinery doesn't currently
have the cast-to type handy, so it continues assuming no-debug
variables have int type, though now at least it warns.
The change to gdb.cp/m-static.exp deserves an explanation:
- gdb_test "print 'gnu_obj_1::method()::sintvar'" "\\$\[0-9\]+ = 4" \
+ gdb_test "print (int) 'gnu_obj_1::method()::sintvar'" "\\$\[0-9\]+ = 4" \
That's printing the "sintvar" function local static of the
"gnu_obj_1::method()" method.
The problem with that test is that that "'S::method()::static_var'"
syntax doesn't really work in C++ as you'd expect. The way to make it
work correctly currently is to quote the method part, not the whole
expression, like:
(gdb) print 'gnu_obj_1::method()'::sintvar
If you wrap the whole expression in quotes, like in m-static.exp, what
really happens is that the parser considers the whole string as a
symbol name, but there's no debug symbol with that name. However,
local statics have linkage and are given a mangled name that demangles
to the same string as the full expression, so that's what GDB prints.
After this commit, and without the cast, the print in m-static.exp
would error out saying that the variable has unknown type:
(gdb) p 'gnu_obj_1::method()::sintvar'
'gnu_obj_1::method()::sintvar' has unknown type; cast it to its declared type
TBC, if currently (even before this series) you try to print any
function local static variable of type other than int, you'll get
bogus results. You can see that with m-static.cc as is, even.
Printing the "svar" local, which is a boolean (1 byte) still prints as
"int" (4 bytes):
(gdb) p 'gnu_obj_1::method()::svar'
$1 = 1
(gdb) ptype 'gnu_obj_1::method()::svar'
type = <data variable, no debug info>
This probably prints some random bogus value on big endian machines.
If 'svar' was of some aggregate type (etc.) we'd still print it as
int, so the problem would have been more obvious... After this
commit, you'll get instead:
(gdb) p 'gnu_obj_1::method()::svar'
'gnu_obj_1::method()::svar' has unknown type; cast it to its declared type
... so at least GDB is no longer misleading. Making GDB find the real
local static debug symbol is the subject of the following patches. In
the end, it'll all "Just Work".
gdb/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* ax-gdb.c: Include "typeprint.h".
(gen_expr_for_cast): New function.
(gen_expr) <OP_CAST, OP_CAST_TYPE>: Use it.
<OP_VAR_VALUE, OP_MSYM_VAR_VALUE>: Error out if the variable's
type is unknown.
* dwarf2read.c (new_symbol_full): Fallback to int instead of
nodebug_data_symbol.
* eval.c: Include "typeprint.h".
(evaluate_subexp_standard) <OP_VAR_VALUE, OP_VAR_MSYM_VALUE>:
Error out if symbol has unknown type.
<UNOP_CAST, UNOP_CAST_TYPE>: Common bits factored out to
evaluate_subexp_for_cast.
(evaluate_subexp_for_address, evaluate_subexp_for_sizeof): Handle
OP_VAR_MSYM_VALUE.
(evaluate_subexp_for_cast): New function.
* gdbtypes.c (init_nodebug_var_type): New function.
(objfile_type): Use it to initialize types of variables with no
debug info.
* typeprint.c (error_unknown_type): New.
* typeprint.h (error_unknown_type): New declaration.
* compile/compile-c-types.c (convert_type_basic): Handle
TYPE_CODE_ERROR; warn and fallback to int for variables with
unknown type.
gdb/testsuite/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* gdb.asm/asm-source.exp: Add casts to int.
* gdb.base/nodebug.c (dataglobal8, dataglobal32_1, dataglobal32_2)
(dataglobal64_1, dataglobal64_2): New globals.
* gdb.base/nodebug.exp: Test different expressions involving the
new globals, with print, whatis and ptype. Add casts to int.
* gdb.base/solib-display.exp: Add casts to int.
* gdb.compile/compile-ifunc.exp: Expect warning. Add cast to int.
* gdb.cp/m-static.exp: Add cast to int.
* gdb.dwarf2/dw2-skip-prologue.exp: Add cast to int.
* gdb.threads/tls-nodebug.exp: Check that gdb errors out printing
tls variable with no debug info without a cast. Test with a cast
to int too.
* gdb.trace/entry-values.exp: Add casts.
A following patch will want to call the new evaluate_var_value
function in another spot.
gdb/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* eval.c (evaluate_var_value): New function, factored out from ...
(evaluate_subexp_standard): ... here.
H.J. Lu
Jan Kratochvil
GDB Administrator
Philippe Waroquiers
Tom Tromey
Simon Marchi
Yao Qi
Pedro Alves
Nick Clifton
John Baldwin
Alexander Fedotov-B55613