This patch adds semantic RTL descriptions to the eBPF instructions
defined in cpu/bpf.cpu. It also contains a couple of minor
improvements.
Tested in bpf-unknown-none targets.
No regressions.
cpu/ChangeLog:
2020-05-28 Jose E. Marchesi <jose.marchesi@oracle.com>
David Faust <david.faust@oracle.com>
* bpf.cpu (define-alu-insn-un): Add definitions of semantics.
(define-alu-insn-mov): Likewise.
(daib): Likewise.
(define-alu-instructions): Likewise.
(define-endian-insn): Likewise.
(define-lddw): Likewise.
(dlabs): Likewise.
(dlind): Likewise.
(dxli): Likewise.
(dxsi): Likewise.
(dsti): Likewise.
(define-ldstx-insns): Likewise.
(define-st-insns): Likewise.
(define-cond-jump-insn): Likewise.
(dcji): Likewise.
(define-condjump-insns): Likewise.
(define-call-insn): Likewise.
(ja): Likewise.
("exit"): Likewise.
(define-atomic-insns): Likewise.
(sem-exchange-and-add): New macro.
* bpf.cpu ("brkpt"): New instruction.
(bpfbf): Set word-bitsize to 32 and insn-endian big.
(h-gpr): Prefer r0 to `a' and r6 to `ctx'.
(h-pc): Expand definition.
* bpf.opc (bpf_print_insn): Set endian_code to BIG.
opcodes/ChangeLog:
2020-05-28 Jose E. Marchesi <jose.marchesi@oracle.com>
David Faust <david.faust@oracle.com>
* bpf-desc.c: Regenerate.
* bpf-opc.h: Likewise.
* bpf-opc.c: Likewise.
* bpf-dis.c: Likewise.
Add a comment to clarify why we temporarily override some of the
context's fields, and especially the per_objfile field. A longer
explanation can be found in this previous commit
44486dcf19 ("gdb: use caller objfile in dwarf_evaluate_loc_desc::push_dwarf_reg_entry_value")
gdb/ChangeLog:
* dwarf2/loc.c (class dwarf_evaluate_loc_desc)
<push_dwarf_reg_entry_value>: Add comment.
Change-Id: I60c6e1062799f729b30a9db78bcb6448783324b4
Python3.9b1 is now available on Rawhide. GDB w/ Python 3.9 support
can be built using the configure switch -with-python=/usr/bin/python3.9.
Attempting to run gdb/Python3.9 segfaults on startup:
#0 0x00007ffff7b0582c in PyEval_ReleaseLock () from /lib64/libpython3.9.so.1.0
#1 0x000000000069ccbf in do_start_initialization ()
at worktree-test1/gdb/python/python.c:1789
#2 _initialize_python ()
at worktree-test1/gdb/python/python.c:1877
#3 0x00000000007afb0a in initialize_all_files () at init.c:237
...
Consulting the the documentation...
https://docs.python.org/3/c-api/init.html
...we find that PyEval_ReleaseLock() has been deprecated since version
3.2. It recommends using PyEval_SaveThread or PyEval_ReleaseThread()
instead. In do_start_initialization, in gdb/python/python.c, we
can replace the calls to PyThreadState_Swap() and PyEval_ReleaseLock()
with a single call to PyEval_SaveThread. (Thanks to Keith Seitz
for working this out.)
With that in place, GDB gets a little bit further. It still dies
on startup, but the backtrace is different:
#0 0x00007ffff7b04306 in PyOS_InterruptOccurred ()
from /lib64/libpython3.9.so.1.0
#1 0x0000000000576e86 in check_quit_flag ()
at worktree-test1/gdb/extension.c:776
#2 0x0000000000576f8a in set_active_ext_lang (now_active=now_active@entry=0x983c00 <extension_language_python>)
at worktree-test1/gdb/extension.c:705
#3 0x000000000069d399 in gdbpy_enter::gdbpy_enter (this=0x7fffffffd2d0,
gdbarch=0x0, language=0x0)
at worktree-test1/gdb/python/python.c:211
#4 0x0000000000686e00 in python_new_inferior (inf=0xddeb10)
at worktree-test1/gdb/python/py-inferior.c:251
#5 0x00000000005d9fb9 in std::function<void (inferior*)>::operator()(inferior*) const (__args#0=<optimized out>, this=0xccad20)
at /usr/include/c++/10/bits/std_function.h:617
#6 gdb::observers::observable<inferior*>::notify (args#0=0xddeb10,
this=<optimized out>)
at worktree-test1/gdb/../gdbsupport/observable.h:106
#7 add_inferior_silent (pid=0)
at worktree-test1/gdb/inferior.c:113
#8 0x00000000005dbcb8 in initialize_inferiors ()
at worktree-test1/gdb/inferior.c:947
...
We checked with some Python Developers and were told that we should
acquire the GIL prior to calling any Python C API function. We
definitely don't have the GIL for calls of PyOS_InterruptOccurred().
I moved class_gdbpy_gil earlier in the file and use it in
gdbpy_check_quit_flag() to acquire (and automatically release) the
GIL.
With those changes in place, I was able to run to a GDB prompt. But,
when trying to quit, it segfaulted again due to due to some other
problems with gdbpy_check_quit_flag():
Thread 1 "gdb" received signal SIGSEGV, Segmentation fault.
0x00007ffff7bbab0c in new_threadstate () from /lib64/libpython3.9.so.1.0
(top-gdb) bt 8
#0 0x00007ffff7bbab0c in new_threadstate () from /lib64/libpython3.9.so.1.0
#1 0x00007ffff7afa5ea in PyGILState_Ensure.cold ()
from /lib64/libpython3.9.so.1.0
#2 0x000000000069b58c in gdbpy_gil::gdbpy_gil (this=<synthetic pointer>)
at worktree-test1/gdb/python/python.c:278
#3 gdbpy_check_quit_flag (extlang=<optimized out>)
at worktree-test1/gdb/python/python.c:278
#4 0x0000000000576e96 in check_quit_flag ()
at worktree-test1/gdb/extension.c:776
#5 0x000000000057700c in restore_active_ext_lang (previous=0xe9c050)
at worktree-test1/gdb/extension.c:729
#6 0x000000000088913a in do_my_cleanups (
pmy_chain=0xc31870 <final_cleanup_chain>,
old_chain=0xae5720 <sentinel_cleanup>)
at worktree-test1/gdbsupport/cleanups.cc:131
#7 do_final_cleanups ()
at worktree-test1/gdbsupport/cleanups.cc:143
In this case, we're trying to call a Python C API function after
Py_Finalize() has been called from finalize_python(). I made
finalize_python set gdb_python_initialized to false and then cause
check_quit_flag() to return early when it's false.
With these changes in place, GDB seems to be working again with
Python3.9b1. I think it likely that there are other problems lurking.
I wouldn't be surprised to find that there are other calls into Python
where we don't first make sure that we have the GIL. Further changes
may well be needed.
I see no regressions testing on Rawhide using a GDB built with the
default Python version (3.8.3) versus one built using Python 3.9b1.
I've also tested on Fedora 28, 29, 30, 31, and 32 (all x86_64) using
the default (though updated) system installed versions of Python on
those OSes. This means that I've tested against Python versions
2.7.15, 2.7.17, 2.7.18, 3.7.7, 3.8.2, and 3.8.3. In each case GDB
still builds without problem and shows no regressions after applying
this patch.
gdb/ChangeLog:
2020-MM-DD Kevin Buettner <kevinb@redhat.com>
Keith Seitz <keiths@redhat.com>
* python/python.c (do_start_initialization): For Python 3.9 and
later, call PyEval_SaveThread instead of PyEval_ReleaseLock.
(class gdbpy_gil): Move to earlier in file.
(finalize_python): Set gdb_python_initialized.
(gdbpy_check_quit_flag): Acquire GIL via gdbpy_gil. Return early
when not initialized.
These failures were caused by the PDP11's mix of little-endian octets
in shorts but shorts in big endian order for long or quad so regexps
did not match. Also tests used addresses as values in .long which
required BRD_RELOC_32 that was not implemented.
* gas/config/tc-pdp11.c (md_number_to_chars): Implement .quad
* gas/testsuite/gas/all/gas.exp: Select alternate test scripts for
pdp11, skip octa test completely.
* gas/testsuite/gas/all/eqv-dot-pdp11.s: Identical to eqv-dot.s
* gas/testsuite/gas/all/eqv-dot-pdp11.d: Match different octet order.
* gas/testsuite/gas/all/cond-pdp11.l: Match different octet order.
* bfd/pdp11.c: Implement BRD_RELOC_32 to relocate the low 16 bits of
addreses in .long (used in testsuites) and .stab values.
When running the testsuite with clang, gdb.base/sigaltstack.c
fails to compile with the following error:
warning: enumeration values 'LEAF' and 'NR_LEVELS' not handled
in switch [-Wswitch]
This prevents the gdb.base/sigaltstack.exp from executing.
This commit fixes.
gdb/testsuite/ChangeLog:
* gdb.base/sigaltstack.c (catcher): Add default case to switch
statement.
In commit
89b07335fe ("Add dwarf2_per_objfile to dwarf_expr_context and dwarf2_frame_cache")
I replaced the offset property of dwarf_expr_context by a per_objfile
property (since we can get the text offset from the objfile). The
previous code in dwarf_evaluate_loc_desc::push_dwarf_reg_entry_value
(dwarf_evaluate_loc_desc derives from dwarf_expr_context) did
temporarily override the offset property while evaluating a DWARF
sub-expression. I speculated that this sub-expression always came from
the same objfile as the outer expression, so I didn't see the need to
temporarily override the per_objfile property in the new code. A later
commit:
9f47c70716 ("Remove dwarf2_per_cu_data::objfile ()")
added the following assertion to verify this:
gdb_assert (this->per_objfile == caller_per_objfile);
It turns out that this is not true. Call sites can refer to function in
another objfile, and therefore the caller's objfile can be different
from the callee's objfile. This can happen when the call site DIE in the
DWARF represents a function call done through a function pointer. The
DIE can't describe statically which function is being called, since it's
variable and not known at compile time. Instead, it provides an
expression that evaluates to the address of the function being called.
In this case, the called function can very well be in a separate
objfile.
Fix this by overriding the per_objfile property while evaluating the
sub-expression.
This was exposed by the gdb.base/catch-load.exp test failing on openSUSE
Tumbleweed with the glibc debug info installed. It was also reported to
fail on Fedora.
When I investigated the problem, the particular call site on which we
did hit the assert was coming from this DIE, in
/usr/lib/debug/lib64/libc-2.31.so-2.31-5.1.x86_64.debug on openSUSE
Tumbleweed:
0x0091aa10: DW_TAG_GNU_call_site
DW_AT_low_pc [DW_FORM_addr] (0x00000000001398e0)
DW_AT_GNU_call_site_target [DW_FORM_exprloc] (DW_OP_fbreg -272, DW_OP_deref)
DW_AT_sibling [DW_FORM_ref4] (0x0091aa2b)
And for you curious out there, this call site is found in this function:
0x0091a91d: DW_TAG_subprogram
DW_AT_external [DW_FORM_flag_present] (true)
DW_AT_name [DW_FORM_strp] ("_dl_catch_exception")
DW_AT_decl_file [DW_FORM_data1] ("/usr/src/debug/glibc-2.31-5.1.x86_64/elf/dl-error-skeleton.c")
...
Which is a function that indeed uses a function pointer.
gdb/ChangeLog:
* dwarf2/loc.c (class dwarf_evaluate_loc_desc)
<push_dwarf_reg_entry_value>: Remove assert. Override
per_objfile with caller_per_objfile.
Change-Id: Ib227d767ce525c10607ab6621a373aaae982c67a
Clang fails to compile three testcases with the following error:
warning: 'register' storage class specifier is deprecated and
incompatible with C++17 [-Wdeprecated-register]
This prevents the following testcases from executing:
gdb.cp/classes.exp
gdb.cp/inherit.exp
gdb.cp/misc.exp
This commit builds those testcases with -Wno-deprecated-register, to
avoid the failure. Note that this commit reveals five "wrong access
specifier for typedef" failures in gdb.cp/classes.exp when compiling
the testsuite with clang.
gdb/testsuite/ChangeLog:
* gdb.cp/classes.exp (prepare_for_testing): Add
additional_flags=-Wno-deprecated-register.
* gdb.cp/inherit.exp (prepare_for_testing): Likewise.
* gdb.cp/misc.exp: Likewise.
There's a PR gold/15646 - "gold-generated .gdb_index has duplicated
symbols that gdb-generated index doesn't", that causes gold to generate
duplicate symbols in the index.
F.i., a namespace N1 declared in a header file can be listed for two CUs that
include the header file:
...
[759] N1:
2 [global type]
3 [global type]
...
This causes a gdb performance problem: f.i. when attempting to set a
breakpoint on a non-existing function N1::misspelled, the symtab for both CUs
will be expanded.
Gdb contains a workaround for this, added in commit 8943b87476 "Work around
gold/15646", that skips duplicate global symbols in the index.
However, the workaround does not check for the symbol kind ("type" in the
example above).
Make the workaround more precise by limiting it to symbol kind "type".
Tested on x86_64-linux, with target boards cc-with-gdb-index and
gold-gdb-index.
gdb/ChangeLog:
2020-05-28 Tom de Vries <tdevries@suse.de>
* dwarf2/read.c (dw2_symtab_iter_next, dw2_expand_marked_cus): Limit
PR gold/15646 workaround to symbol kind "type".
When running the testsuite with clang, gdb.linespec/cpls-ops.cc
fails to compile with the following errors:
warning: 'operator new' should not return a null pointer unless
it is declared 'throw()' or 'noexcept' [-Wnew-returns-null]
warning: 'operator new[]' should not return a null pointer unless
it is declared 'throw()' or 'noexcept' [-Wnew-returns-null]
This prevents the gdb.linespec/cpls-ops.exp testcase from executing.
This commit fixes.
gdb/testsuite/ChangeLog:
* gdb.linespec/cpls-ops.cc (dummy): New static global.
(test_op_new::operator new): Add return statement.
(test_op_new_array::operator new[]): Likewise.
Since this value is used in fields of type tilepro_pipeline (as
NO_PIPELINE, see tc-tilepro.c) it is appropriate to put it in
the tilepro_pipelen enum. This avoids a warning about converting from
one enum type to another.
PR 26044
* opcode/tilepro.h (TILEPRO_NUM_PIPELINE_ENCODINGS): Move to
tilepro_pipeline enum.
Add a configure option, --enable-textrel-check=[no|yes|warning|error],
to decide what ELF linker should do by default with DT_TEXTREL in an
executable or shared library.
PR ld/20824
* NEWS: Mention --enable-textrel-check=[no|yes|warning|error].
* configure.ac: Add --enable-textrel-check=[no|yes|warning|error].
(DEFAULT_LD_TEXTREL_CHECK): New AC_DEFINE_UNQUOTED.
(DEFAULT_LD_TEXTREL_CHECK_WARNING): Likewise.
* ldmain.c (main): Initialize link_info.textrel_check to
DEFAULT_LD_TEXTREL_CHECK.
* lexsup.c (ld_options): Check DEFAULT_LD_TEXTREL_CHECK_WARNING.
* config.in: Regenerated.
* configure: Likewise.
* lexsup.c (parse_args): Generate an error if a name is not
provided to the -Map option.
(ld_options): Mention that the -Map option supports a directory
name as an argument.
* NEWS: Remove mention of support for an empty string as an
argument to -Map.
* ld.texi: Likewise.
PR gas/26001
* gas/config/tc-pdp11.c (parse_reg): Distinguish register names from
symbols that begin with a register name.
* gas/testsuite/gas/pdp11/pdp11.exp: Add test of such symbols.
* gas/testsuite/gas/pdp11/pr26001.s: Likewise.
* gas/testsuite/gas/pdp11/pr26001.d: Likewise.
The next pointer of struct riscv_csr_extra was not always initilized
to NULL or a valid pointer, causing the assembler to attempt to read
through an uninitialized pointer on startup.
gas/ChangeLog:
* config/tc-riscv.c (riscv_init_csr_hash): NULL initilize next
pointer when creating struct riscv_csr_extra.
Noticed by my autotester covering cris-axis-linux-gnu:
...
Running <x>/src/ld/testsuite/ld-elf/elf.exp ...
XPASS: ld-elf/pr19539
...
This was apparently as intended, so I'm just adjusting the xfail.
PR ld/22909
* testsuite/ld-elf/pr19539.d: Don't xfail for cris*-*-*.
gdb.linespec/cp-completion-aliases.exp is calling
test_gdb_complete_{tab,cmd}_unique and
test_gdb_complete_{tab,cmd}_multiple separately for each use case.
I.e., testing once for TAB completion and once for the "complete"
command. There's no need to do that explicitly and separately, we
have wrapper procedures to do that for us.
gdb/testsuite/ChangeLog:
2020-05-27 Pedro Alves <palves@redhat.com>
* gdb.linespec/cp-completion-aliases.exp: Remove readline_is_used
check. Use test_gdb_complete_unique instead of
test_gdb_complete_tab_unique + test_gdb_complete_cmd_unique. Use
test_gdb_complete_multiple instead of
test_gdb_complete_tab_multiple + test_gdb_complete_cmd_multiple.
An earlier patch added the add_partial_symbol helper function to
dwarf2/read.c. However, a couple of calls to add_psymbol_to_list were
left in place. It turns out that these calls slow down partial symbol
reading, because they still go via the path that tries to needlessly
demangle already-demangled names.
This patch improves the performance of partial symbol reading by
changing this code to use add_partial_symbol instead.
The run previous to this had times of (see the first patch in the
series for an explanation):
gdb 1.64
libxul 1.99
Ada 2.47
This patch improves the times to:
gdb 1.47
libxul 1.89
Ada 2.39
gdb/ChangeLog
2020-05-27 Tom Tromey <tromey@adacore.com>
* dwarf2/read.c (load_partial_dies): Use add_partial_symbol.
Profiling showed that calls to abbrev_table::lookup_abbrev were "too
visible". As these are just forwarding calls to the hash table, this
patch inlines the lookup. Also, htab_find_with_hash is used, avoiding
another call.
The run previous to this had times of (see the first patch in the
series for an explanation):
gdb 1.69
libxul 2.02
Ada 2.52
This patch improves the times to:
gdb 1.64
libxul 1.99
Ada 2.47
gdb/ChangeLog
2020-05-27 Tom Tromey <tromey@adacore.com>
* dwarf2/abbrev.h (struct abbrev_table) <lookup_abbrev>: Inline.
Use htab_find_with_hash.
<add_abbrev>: Remove "abbrev_number" parameter.
* dwarf2/abbrev.c (abbrev_table::add_abbrev): Remove
"abbrev_number" parameter. Use htab_find_slot_with_hash.
(hash_abbrev): Add comment.
(abbrev_table::lookup_abbrev): Move to header file.
(abbrev_table::read): Update.
Currently the name of a partial DIE is computed eagerly. However, the
name is not always needed. This patch changes partial DIEs to compute
their name lazily, improving performance by avoiding unnecessary name
computations.
The run previous to this had times of (see the first patch in the
series for an explanation):
gdb 1.88
libxul 2.11
Ada 2.60
This patch improves the times to:
gdb 1.69
libxul 2.02
Ada 2.52
gdb/ChangeLog
2020-05-27 Tom Tromey <tromey@adacore.com>
* dwarf2/read.c (struct partial_die_info) <name>: Declare new
method.
<canonical_name>: New member.
<raw_name>: Rename from "name".
(partial_die_info): Initialize canonical_name.
(scan_partial_symbols): Check raw_name.
(partial_die_parent_scope, partial_die_full_name)
(add_partial_symbol, add_partial_subprogram)
(add_partial_enumeration, load_partial_dies): Use "name" method.
(partial_die_info::name): New method.
(partial_die_info::read, guess_partial_die_structure_name)
(partial_die_info::fixup): Update.
This inlines a couple of methods on struct attribute, improving the
performance of DWARF partial symbol reading. These methods were
discovered as hot spots using callgrind.
For this patch, and for all the patches in this series, I tested gdb's
performance on three programs:
1. gdb itself -- I built gdb and copied it to /tmp, ensuring that the
same version was used in all tests.
2. The system libxul.so, the main library of Firefox. I installed the
separate debuginfo and ensured that gdb read it.
3. A large-ish Ada program that I happen to have.
I ran gdb 10 times like:
/bin/time -f %e \
./gdb/gdb --data-directory ./gdb/data-directory -nx \
-iex 'set debug-file-directory /usr/lib/debug' \
-batch $X
... where $X was the test executable. Then I computed the mean time.
This was all done with a standard (-g -O2) build of gdb.
The baseline times were
gdb 1.90
libxul 2.12
Ada 2.61
This patch brings the numbers down to
gdb 1.88
libxul 2.11
Ada 2.60
Not a huge change, but still visible in the results.
gdb/ChangeLog
2020-05-27 Tom Tromey <tromey@adacore.com>
* dwarf2/attribute.h (struct attribute) <form_is_ref>: Inline.
<get_ref_die_offset>: Inline.
<get_ref_die_offset_complaint>: New method.
* dwarf2/attribute.c (attribute::form_is_ref): Move to header.
(attribute::get_ref_die_offset_complaint): Rename from
get_ref_die_offset. Just issue complaint.
Fixes this testsuite fail on Windows:
FAIL: gdb.base/bad-file.exp: directory
If both tries to open the file fail (without and with ".exe"), use the
errno value of the first try.
gdb/ChangeLog:
2020-05-27 Hannes Domani <ssbssa@yahoo.de>
* exec.c (exec_file_attach): Use errno value of first openp failure.
Only the process handle returned by OpenProcess or CreateProcess needs to
be closed, the one provided by WaitForDebugEvent is closed automatically.
gdbserver/ChangeLog:
2020-05-27 Hannes Domani <ssbssa@yahoo.de>
* win32-low.cc (do_initial_child_stuff): Set open_process_used.
(win32_clear_inferiors): Use open_process_used.
(get_child_debug_event): Likewise.
I sometimes encountered a weird breakpoint failure when using start:
(gdb) start
Temporary breakpoint 2 at 0x40162d: file gdb-25911.c, line 4.
Starting program: C:\src\tests\gdb-25911.exe
Warning:
Cannot insert breakpoint 2.
Cannot access memory at address 0x401628
After trying a lot of combinations, I found a way to reproduce it:
(gdb) file gdb-25987.exe
Reading symbols from gdb-25987.exe...
(gdb) start
Temporary breakpoint 1 at 0x401638: file gdb-25987.cpp, line 13.
Starting program: C:\src\tests\gdb-25987.exe
Temporary breakpoint 1, main () at gdb-25987.cpp:13
13 int main() {
(gdb) c
Continuing.
Program received signal SIGSEGV, Segmentation fault.
MyClass::call (this=0x3d20d0) at gdb-25987.cpp:8
8 *(char*)(nullptr) = 1;
(gdb) kill
Kill the program being debugged? (y or n) y
[Inferior 1 (process 1140) killed]
(gdb) file gdb-25911.exe
Load new symbol table from "gdb-25911.exe"? (y or n) y
Reading symbols from gdb-25911.exe...
(gdb) start
Temporary breakpoint 2 at 0x40162d: file gdb-25911.c, line 4.
Starting program: C:\src\tests\gdb-25911.exe
Warning:
Cannot insert breakpoint 2.
Cannot access memory at address 0x401628
Command aborted.
The actual failure was that ReadProcessMemory used a process handle that
was no longer valid.
And the underlying reason was that the windows_thread_info destructor
closes a thread handle that was provided earlier by WaitForDebugEvent.
But since this is not allowed (and it was actually already closed at this
point, and the handle value reused), this closed another still-needed handle.
gdb/ChangeLog:
2020-05-27 Hannes Domani <ssbssa@yahoo.de>
* nat/windows-nat.c (windows_thread_info::~windows_thread_info):
Don't close thread handle.
* lexsup.c (parse_args): If the map filename is defined but empty
create a name based upon the output file name. If the name is
defined but refers to a directory create a file inside the
directory based on the output file name.
* ld.texi: Document the new feature.
* testsuite/ld-script/map-address.exp: Add test of new feature.
* NEWS: Mention the new feature.
This changes the DWARF reader to share partial symtabs (or indices if
they are available) across objfiles. This has a few parts.
* If multiple objfiles backed by the same BFD can share partial symtabs
(see below), a single dwarf2_per_bfd is created. It is stored in the
per-bfd `dwarf2_per_bfd_bfd_data_key` registry. Multiple
dwarf2_per_objfile objects will point to the same instance. The
lifetime of these dwarf2_per_bfd objects is naturally handled. When
all the objfiles using the BFD are destroyed, the BFD's refount drops
to 0, which triggers the removal of the corresponding dwarf2_per_bfd
object from the registry and its destruction.
* If multiple objfiles backed by the same BFD can't share partial
symtabs (see below), one dwarf2_per_bfd object is created for each
objfile. Each dwarf2_per_objfile will point to their own instance of
dwarf2_per_bfd. These instances of dwarf2_per_bfd are kept in a
per-objfile registry, meaning that when the objfile gets destroyed,
the dwarf2_per_bfd instance gets destroyed as well.
* objfile::partial_symtabs is changed to be a shared_ptr again. This
lets us stash a second reference in dwarf2_per_bfd; if the DWARF
data is being shared, we can simply copy this value to the new
objfile.
* Two dwarf2_per_objfile objects backed by the same BFD may share a
dwarf2_per_bfd instance if:
* No other symbol reader has found symbols, and
* No BFD section rqeuires relocation
gdb/ChangeLog:
YYYY-MM-DD Tom Tromey <tom@tromey.com>
YYYY-MM-DD Simon Marchi <simon.marchi@efficios.com>
* objfiles.h (struct objfile) <partial_symtabs>: Now a
shared_ptr.
* dwarf2/read.h (struct dwarf2_per_objfile) <partial_symtabs>: New
member.
* dwarf2/read.c (dwarf2_per_bfd_bfd_data_key,
dwarf2_per_bfd_objfile_data_key>: New globals.
(dwarf2_has_info): Use shared dwarf2_per_bfd if possible.
(dwarf2_get_section_info): Use get_dwarf2_per_objfile.
(dwarf2_initialize_objfile): Consider cases where per_bfd can be
shared.
(dwarf2_build_psymtabs): Set objfile::partial_symtabs and
short-circuit when sharing.
(dwarf2_build_psymtabs): Set dwarf2_per_objfile::partial_symtabs.
(dwarf2_psymtab::expand_psymtab): Use free_cached_comp_units.
Change-Id: I868c64448589102ab8cbb8f06c31a8de50a14004
The `line_header_hash` field of `struct dwarf2_per_bfd` contains some
`struct line_header` objects. A `struct line_header` objects contains
some `file_entry` objects. A `file_entry` object contains a pointer to
the `symtab` object created from it. The `line_header_hash` is
therefore ultimately objfile-dependent and can't be shared as-is between
objfiles.
Move it from `dwarf2_per_bfd` to `dwarf2_per_objfile`.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_bfd) <line_header_hash>: Move
to...
(struct dwarf2_per_objfile) <line_header_hash>: ... here.
* dwarf2/read.c (handle_DW_AT_stmt_list): Update.
Change-Id: I8d2ee04df4f4847c2db99061fc976c35af98ac71
mapped_debug_names currently has a dwarf2_per_objfile field. Since we
want it to become objfile-independent, this field must be removed.
This patch removes it, and then arranges for all methods that needed it
to accept a dwarf2_per_objfile parameter. This trickles down at various
places, like the dw2_debug_names_iterator type.
Ultimately, the objfile only seems to be needed because we might need to
read a string from the string section. For that, we might need to read
in the section, and if it's a relocatable section, the objfile is needed
in order to do the relocation. This pattern happens often (that we to
pass an objfile only because a section might be read). I think it's a
bit ugly, but I don't have a good alternative right now.
gdb/ChangeLog:
* dwarf2/read.c (struct mapped_index_base) <symbol_name_at,
build_name_components, find_name_components_bounds>:
Add per_objfile parameter.
(struct mapped_index) <symbol_name_at>: Likewise.
(struct mapped_debug_names): Remove constructor.
<dwarf2_per_objfile>: Remove field.
<namei_to_name, symbol_name_at>: Add per_objfile parameter.
(mapped_index_base::find_name_components_bounds,
mapped_index_base::build_name_components,
dw2_expand_symtabs_matching_symbol): Likewise.
(class mock_mapped_index) <symbol_name_at>: Likewise.
(check_match): Likewise.
(check_find_bounds_finds): Likewise.
(test_mapped_index_find_name_component_bounds): Update.
(CHECK_MATCH): Update.
(dw2_expand_symtabs_matching): Update.
(class dw2_debug_names_iterator) <dw2_debug_names_iterator>: Add
per_objfile parameter.
<find_vec_in_debug_names>: Likewise.
<m_per_objfile>: New field.
(mapped_debug_names::namei_to_name): Add dwarf2_per_objfile
parameter.
(dw2_debug_names_iterator::find_vec_in_debug_names): Likewise.
(dw2_debug_names_iterator::next): Update.
(dw2_debug_names_lookup_symbol): Update.
(dw2_debug_names_expand_symtabs_for_function): Update.
(dw2_debug_names_map_matching_symbols): Update.
(dw2_debug_names_expand_symtabs_matching): Update.
(dwarf2_read_debug_names): Update.
Change-Id: I00ee0d939390d353442675c7d400a261307c57a1
The dwarf2_per_cu_data type is going to become objfile-independent,
while the dwarf2_cu type will stay object-dependent. This patch removes
the backlink from dwarf2_per_cu_data to dwarf2_cu, in favor of the
dwarf2_per_objfile::m_dwarf2_cus map. It maps dwarf2_per_cu_data
objects to the corresponding dwarf2_cu objects for this objfile. If a
CU has been read in in the context of this objfile, then an entry will
be present in the map.
The dwarf2_cu objects that are read in are currently kept in a linked
list rooted in the dwarf2_per_bfd. Except that the dwarf2_cu objects
are not simply linked together, they are interleaved with their
corresponding dwarf2_per_cu_data objects. So if we have CUs A and B
read in, the dwarf2_per_bfd::read_in_chain will point to a chain like
this (DPCD == dwarf2_per_cu_data, DC == dwarf2_cu):
DPCD A -> DC A -> DPCD B -> DC B
Obviously, this can't stay as is, since a same CU can be read in for an
objfile but not read in for another objfile sharing the same BFD, and
the dwarf2_per_cu_data::cu link is removed. This is all replaced by
the dwarf2_per_objfile::m_dwarf2_cus map.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_cu): Forward-declare.
(struct dwarf2_per_bfd) <free_cached_comp_units>: Remove,
move to dwarf2_per_objfile.
<read_in_chain>: Remove.
(struct dwarf2_per_objfile) <get_cu, set_cu, remove_cu,
remove_all_cus, age_comp_units>: New methods.
<m_dwarf2_cus>: New member.
(struct dwarf2_per_cu_data) <cu>: Remove.
* dwarf2/read.c (struct dwarf2_cu) <read_in_chain>: Remove.
(age_cached_comp_units, free_one_cached_comp_unit): Remove,
moved to methods of dwarf2_per_objfile.
(dwarf2_clear_marks): Remove.
(dwarf2_queue_item::~dwarf2_queue_item): Update.
(dwarf2_per_bfd::~dwarf2_per_bfd): Don't free dwarf2_cus.
(dwarf2_per_bfd::free_cached_comp_units): Remove.
(dwarf2_per_objfile::remove_all_cus): New.
(class free_cached_comp_units) <~free_cached_comp_units>:
Update.
(load_cu): Update.
(dw2_do_instantiate_symtab): Adjust.
(fill_in_sig_entry_from_dwo_entry): Adjust.
(cutu_reader::init_tu_and_read_dwo_dies): Update.
(cutu_reader::cutu_reader): Likewise.
(cutu_reader::keep): Use dwarf2_per_objfile::set_cu.
(cutu_reader::cutu_reader): Use dwarf2_per_objfile::get_cu.
(process_psymtab_comp_unit): Use dwarf2_per_objfile::remove_cu
and dwarf2_per_objfile::age_comp_units.
(load_partial_comp_unit): Update.
(maybe_queue_comp_unit): Use dwarf2_per_objfile::get_cu.
(process_queue): Likewise.
(find_partial_die): Use dwarf2_per_objfile::get_cu instead of cu
backlink.
(dwarf2_read_addr_index): Likewise.
(follow_die_offset): Likewise.
(dwarf2_fetch_die_loc_sect_off): Likewise.
(dwarf2_fetch_constant_bytes): Likewise.
(dwarf2_fetch_die_type_sect_off): Likewise.
(follow_die_sig_1): Likewise.
(load_full_type_unit): Likewise.
(read_signatured_type): Likewise.
(dwarf2_cu::dwarf2_cu): Don't set cu field.
(dwarf2_cu::~dwarf2_cu): Remove.
(dwarf2_per_objfile::get_cu): New.
(dwarf2_per_objfile::set_cu): New.
(age_cached_comp_units): Rename to...
(dwarf2_per_objfile::age_comp_units): ... this. Adjust
to std::unordered_map.
(free_one_cached_comp_unit): Rename to...
(dwarf2_per_objfile::remove_cu): ... this. Adjust
to std::unordered_map.
(dwarf2_per_objfile::~dwarf2_per_objfile): New.
(dwarf2_mark_helper): Use dwarf2_per_objfile::get_cu, expect
a dwarf2_per_objfile in data.
(dwarf2_mark): Pass dwarf2_per_objfile in data to htab_traverse.
(dwarf2_clear_marks): Remove.
Change-Id: Ia33ac71c79b2de4710569008e22a6563a1505cde
It is possible, seemingly for a special case described in
find_partial_die, for cutu_reader to re-use an existing dwarf2_cu
instead of creating a new one. This happens when running this test, for
example:
make check TESTS="gdb.dwarf2/fission-reread.exp"
Right now the, `use_existing_cu` flag tells cutu_reader to use the
dwarf2_cu object at dwarf2_per_cu_data::cu. However, we'll remove that
field, so we need to find another solution.
This situation arises when some caller up the stack has already created
the dwarf2_cu to read a dwarf2_per_cu_data, but needs to re-read it with
some other parameters. Therefore, it's possible to just have that
caller pass down the dwarf2_cu object to use as a `existing_cu`
parameter. If `existing_cu` is NULL, it tells cutu_reader that it needs
to instantiate a new one.
gdb/ChangeLog:
* dwarf2/read.c (class cutu_reader) <cutu_reader>: Replace
`int use_existing_cu` parameter with `dwarf2_cu *existing_cu`.
(init_tu_and_read_dwo_dies): Likewise.
(cutu_reader::init_tu_and_read_dwo_dies): Likewise.
(cutu_reader::cutu_reader): Likewise.
(load_partial_comp_unit): Likewise.
(process_psymtab_comp_unit): Update.
(build_type_psymtabs_1): Update.
(process_skeletonless_type_unit): Update.
(load_full_comp_unit): Update.
(find_partial_die): Update.
(dwarf2_read_addr_index): Update.
(read_signatured_type): Update.
Change-Id: Id03e3bc3de3cf99d9e4b4080ad83b029c93bf434
The per_cu_header_read_in function allows obtaining a filled
comp_unit_head object for a given dwarf2_per_cu_data object. If a
dwarf2_cu object exists for this dwarf2_per_cu_data, then it just
returns a pointer to the comp_unit_head from that dwarf2_cu. Otherwise,
it reads the header into a temporary buffer provided by the caller, and
returns a pointer to that.
Since the dwarf2_per_cu_data::cu link is going to be removed
(dwarf2_per_cu_data will become objfile-independent while dwarf2_cu
stays objfile-dependent), we cannot rely anymore on returning the header
from the dwarf2_cu object.
The not too complex solution implemented by this patch is to keep a copy
of the header in the dwarf2_per_cu_data object, independent from the
copy in dwarf2_cu. The new copy is only used in the addr_size,
offset_size and ref_addr_size methods of dwarf2_per_cu_data.
There's nothing intrinsic to the comp_unit_head object that prevents it
to be shared between two dwarf2_cu objects (belonging to different
objfiles) representing the same CU. In other words, I think we could
eventually get rid of the copy in dwarf2_cu to only keep the one in
dwarf2_per_cu_data. It is not trivial, however, so I have decided not
to do it for the moment.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_cu_data) <m_header,
m_header_read_in>: New fields.
<get_header>: New method.
* dwarf2/read.c (per_cu_header_read_in): Remove.
(dwarf2_per_cu_data::get_header): New.
(dwarf2_per_cu_data::addr_size): Update.
(dwarf2_per_cu_data::offset_size): Update.
(dwarf2_per_cu_data::ref_addr_size): Update.
Change-Id: Id7541fca7562843eba110ece21c4df38d45fca23
In a subsequent patch, the dwarf2_per_cu_data::cu link will be removed.
dwarf2_cu objects will instead need to be looked up from a per-objfile
map, using the dwarf2_per_cu_data object as the key.
To make it easier for some callers, this patch makes load_cu return the
dwarf2_cu it creates. If the caller needs to use the created dwarf2_cu,
it will have it available right away, rather than having to do a map
lookup.
At the same time, this allows changing queue_and_load_all_dwo_tus to
take a dwarf2_cu instead of a dwarf2_per_cu_data.
gdb/ChangeLog:
* dwarf2/read.c (load_cu): Return dwarf2_cu.
(dw2_do_instantiate_symtab): Update.
(queue_and_load_all_dwo_tus): Change parameter from
dwarf2_per_cu_data to dwarf2_cu.
(dwarf2_fetch_die_loc_sect_off): Update.
(dwarf2_fetch_constant_bytes): Update.
(dwarf2_fetch_die_type_sect_off): Update.
Change-Id: I8a04c5d1b8cc661b8203f97999258ba8e04e1765
These two functions work on a dwarf2_cu. It is currently obtained from
the per_cu->cu link, which we want to remove. Make them accept the
dwarf2_cu directly as a parameter. This moves the per_cu->cu references
one level up, but that one will be removed too in a subsequent patch.
gdb/ChangeLog:
* dwarf2/read.c (process_full_comp_unit,
process_full_type_unit): Remove per_cu, per_objfile paramters.
Add dwarf2_cu parameter.
(process_queue): Update.
Change-Id: I1027d36986073ac991e198e06f9d51341dc19c6e
All these functions actually only need to receive a dwarf2_per_bfd, pass
that instead of dwarf2_per_objfile.
gdb/ChangeLog:
* dwarf2/read.c (create_cu_from_index_list): Replace
dwarf2_per_objfile parameter with dwarf2_per_bfd.
(create_cus_from_index_list): Likewise.
(create_cus_from_index): Likewise.
(create_signatured_type_table_from_index): Likewise.
(create_cus_from_debug_names_list): Likewise.
(create_cus_from_debug_names): Likewise.
(dwarf2_read_gdb_index): Update.
(dwarf2_read_debug_names): Update.
Change-Id: I8cd7dc04bf815723a48745e7e9b283663dccc1ac
signatured_type has a link to the "struct type". However, types are
inherently objfile-specific, so once sharing is implemented, this will
be incorrect.
This patch moves the type to a new map in the DWARF unshareable
object.
gdb/ChangeLog:
YYYY-MM-DD Tom Tromey <tom@tromey.com>
YYYY-MM-DD Simon Marchi <simon.marchi@efficios.com>
* dwarf2/read.h (struct dwarf2_per_objfile)
<get_type_for_signatured_type, set_type_for_signatured_type>:
New methods.
<m_type_map>: New member.
(struct signatured_type) <type>: Remove.
* dwarf2/read.c
(dwarf2_per_objfile::get_type_for_signatured_type,
dwarf2_per_objfile::set_type_for_signatured_type): New.
(get_signatured_type): Use new methods.
Change-Id: I765ae3c43fae1064f51ced352167a57638609f02
type_unit_group has links to the compunit_symtab and other symtabs.
However, once this object is shared across objfiles, this will no
longer be ok.
This patch introduces a new type_unit_group_unshareable and arranges to
store a map from type unit groups to type_unit_group_unshareable objects
in dwarf2_per_objfile.
gdb/ChangeLog:
YYYY-MM-DD Tom Tromey <tom@tromey.com>
YYYY-MM-DD Simon Marchi <simon.marchi@efficios.com>
* dwarf2/read.h (struct type_unit_group_unshareable): New.
(struct dwarf2_per_objfile) <type_units>: New member.
<get_type_unit_group_unshareable>: New method.
* dwarf2/read.c (struct type_unit_group) <compunit_symtab,
num_symtabs, symtabs>: Remove; move to
type_unit_group_unshareable.
(dwarf2_per_objfile::get_type_unit_group_unshareable): New.
(process_full_type_unit, dwarf2_cu::setup_type_unit_groups)
(dwarf2_cu::setup_type_unit_groups): Use type_unit_group_unshareable.
Change-Id: I1fec2fab59e0ec40fee3614fc821172a469c0e41
This patch removes the remaining references to that field in obvious
ways (the same object is already available some other way in these
contexts).
gdb/ChangeLog:
* dwarf2/read.c (process_psymtab_comp_unit): Remove reference to
dwarf2_per_cu_data::dwarf2_per_objfile.
(compute_compunit_symtab_includes): Likewise.
(dwarf2_cu::start_symtab): Likewise.
Change-Id: I965700fa793d8457711a2d6ae448aaefd779eb96
Max Filippov
GDB Administrator
David Faust
Jose E. Marchesi
Simon Marchi
Kevin Buettner
Stephen Casner
Gary Benson
Nick Clifton
Simon Marchi
Tom de Vries
Alan Modra
H.J. Lu
Simon Cook
Hans-Peter Nilsson
Pedro Alves
Tom Tromey
Hannes Domani
Tom Tromey