The following patch adds a hash type for gdb::string_view in gdbsupport,
which will use the fast_hash function. Move the latter to gdbsupport.
Change-Id: Id74510e17801e775bd5ffa5f443713d79adf14ad
Approved-By: Andrew Burgess <aburgess@redhat.com>
This commit is the result of running the gdb/copyright.py script,
which automated the update of the copyright year range for all
source files managed by the GDB project to be updated to include
year 2023.
PR gdb/28947
The address_significant gdbarch setting was introduced as a way to remove
non-address bits from pointers, and it is specified by a constant. This
constant represents the number of address bits in a pointer.
Right now AArch64 is the only architecture that uses it, and 56 was a
correct option so far.
But if we are using Pointer Authentication (PAuth), we might use up to 2 bytes
from the address space to store the required information. We could also have
cases where we're using both PAuth and MTE.
We could adjust the constant to 48 to cover those cases, but this doesn't
cover the case where GDB needs to sign-extend kernel addresses after removal
of the non-address bits.
This has worked so far because bit 55 is used to select between kernel-space
and user-space addresses. But trying to clear a range of bits crossing the
bit 55 boundary requires the hook to be smarter.
The following patch renames the gdbarch hook from significant_addr_bit to
remove_non_address_bits and passes a pointer as opposed to the number of
bits. The hook is now responsible for removing the required non-address bits
and sign-extending the address if needed.
While at it, make GDB and GDBServer share some more code for aarch64 and add a
new arch-specific testcase gdb.arch/aarch64-non-address-bits.exp.
Bug-url: https://sourceware.org/bugzilla/show_bug.cgi?id=28947
Approved-By: Simon Marchi <simon.marchi@efficios.com>
It seems to me that streq and compare_cstrings belong near the other
string utility functions in common-utils.h; and furthermore that streq
ought to be inlined. This patch makes this change.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
I stumbled across subset_compare today, and after looking at the
callers I realized it could be removed and replaced with calls to
startswith.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
The throw_perror_with_name function is not used outside of utils.c
right now. And as perror_with_name is just a wrapper around
throw_perror_with_name, then any future calls would be to
perror_with_name.
Lets make throw_perror_with_name static.
There should be no user visible changes after this commit.
fprintf_symbol_filtered is misnamed, because whether filtering happens
is now up to the stream. This renames it to fprintf_symbol, which
isn't a great name (the first "f" doesn't mean much and the second one
is truly meaningless here), but "print_symbol" was already taken.
puts_filtered_tabular is now misnamed, because whether filtering
happens is now up to the stream. So, rename it. (This function is
pretty weird, and should probably be rewritten to avoid using the
chars_printed global, and moved into objc-lang.c. However, I haven't
done so.)
Now that filtered and unfiltered output can be treated identically, we
can unify the printf family of functions. This is done under the name
"gdb_printf". Most of this patch was written by script.
Now that filtered and unfiltered output can be treated identically, we
can unify the putc family of functions. This is done under the name
"gdb_putc". Most of this patch was written by script.
Now that filtered and unfiltered output can be treated identically, we
can unify the puts family of functions. This is done under the name
"gdb_puts". Most of this patch was written by script.
Now that filtered and unfiltered output can be treated identically, we
can unify the vprintf family of functions: vprintf_filtered,
vprintf_unfiltered, vfprintf_filtered and vfprintf_unfiltered. (For
the gdb_stdout variants, recall that only printf_unfiltered gets truly
unfiltered output at this point.) This removes one such function and
renames the remaining two to "gdb_vprintf". All callers are updated.
Much of this patch was written by script.
This rewrites the output pager as a ui_file implementation.
A new header is introduced to declare the pager class. The
implementation remains in utils.c for the time being, because there
are some static globals there that must be used by this code. (This
could be cleaned up at some future date.)
I went through all the text output in gdb to ensure that this change
should be ok. There are a few cases:
* Any existing call to printf_unfiltered is required to be avoid the
pager. This is ensured directly in the implementation.
* All remaining calls to the f*_unfiltered functions -- the ones that
take an explicit ui_file -- either send to an unfiltered stream
(e.g., gdb_stderr), which is obviously ok; or conditionally send to
gdb_stdout
I investigated all such calls by searching for:
grep -e '\bf[a-z0-9_]*_unfiltered' *.[chyl] */*.[ch] | grep -v gdb_stdlog | grep -v gdb_stderr
This yields a number of candidates to check.
* The breakpoint _print_recreate family, and
save_trace_state_variables. These are used for "save" commands
and so are fine.
* Things printing to a temporary stream. Obviously ok.
* Disassembly selftests.
* print_gdb_help - this is non-obvious, but ok because paging isn't
yet enabled at this point during startup.
* serial.c - doens't use gdb_stdout
* The code in compile/. This is all printing to a file.
* DWARF DIE dumping - doesn't reference gdb_stdout.
* Calls to the _filtered form -- these are all clearly ok, because if
they are using gdb_stdout, then filtering will still apply; and if
not, then filtering never applied and still will not.
Therefore, at this point, there is no longer any distinction between
all the other _filtered and _unfiltered calls, and they can be
unified.
In this patch, take special note of the vfprintf_maybe_filtered and
ui_file::vprintf change. This is one instance of the above idea,
erasing the distinction between filtered and unfiltered -- in this
part of the change, the "unfiltered_output" flag is never passe to
cli_ui_out. Subsequent patches will go much further in this
direction.
Also note the can_emit_style_escape changes in ui-file.c. Checking
against gdb_stdout or gdb_stderr was always a bit of a hack; and now
it is no longer needed, because this is decision can be more fully
delegated to the particular ui_file implementation.
ui_file::can_page is removed, because this patch removed the only call
to it.
I think this is the main part of fixing PR cli/7234.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=7234
At the end of this series, the use of unfiltered output will be very
restricted -- only places that definitely need it will use it. To
this end, I thought it would be good to reduce the number of
_unfiltered APIs that are exposed. This patch changes gdb so that
only printf_unfiltered exists. (After this patch, the f* variants
still exist as well, but those will be removed later.)
This adds a "timestamped_file" subclass of ui_file. This class adds a
timestamp to its output when appropriate. That is, it follows the
rule already used in vfprintf_unfiltered of adding a timestamp at most
once per write.
The new class is not yet used.
This patch adds support for wild template parameter list matches, similar
to how ABI tags or function overloads are now handled.
With this patch, users will be able to "gloss over" the details of matching
template parameter lists. This is accomplished by adding (yet more) logic
to strncmp_iw_with_mode to skip parameter lists if none is explicitly given
by the user.
Here's a simple example using gdb.linespec/cpls-ops.exp:
Before
------
(gdb) ptype test_op_call
type = struct test_op_call {
public:
void operator()(void);
void operator()(int);
void operator()(long);
void operator()<int>(int *);
}
(gdb) b test_op_call::operator()
Breakpoint 1 at 0x400583: test_op_call::operator(). (3 locations)
(gdb) i b
Num Type Disp Enb Address What
1 breakpoint keep y <MULTIPLE>
1.1 y 0x400583 in test_op_call::operator()(int)
at cpls-ops.cc:43
1.2 y 0x40058e in test_op_call::operator()()
at cpls-ops.cc:47
1.3 y 0x40059e in test_op_call::operator()(long)
at cpls-ops.cc:51
The breakpoint at test_op_call::operator()<int> was never set.
After
-----
(gdb) b test_op_call::operator()
Breakpoint 1 at 0x400583: test_op_call::operator(). (4 locations)
(gdb) i b
Num Type Disp Enb Address What
1 breakpoint keep y <MULTIPLE>
1.1 y 0x400583 in test_op_call::operator()(int)
at cpls-ops.cc:43
1.2 y 0x40058e in test_op_call::operator()()
at cpls-ops.cc:47
1.3 y 0x40059e in test_op_call::operator()(long)
at cpls-ops.cc:51
1.4 y 0x4008d0 in test_op_call::operator()<int>(int*)
at cpls-ops.cc:57
Similar to how scope lookups work, passing "-qualified" to the break command
will cause a literal lookup of the symbol. In the example immediately above,
this will cause GDB to only find the three non-template functions.
I think it only really makes sense to call wrap_here with an argument
consisting solely of spaces. Given this, it seemed better to me that
the argument be an int, rather than a string. This patch is the
result. Much of it was written by a script.
In my tour of the ui_file subsystem, I found that fputstr and fputstrn
can be simplified. The _filtered forms are never used (and IMO
unlikely to ever be used) and so can be removed. And, the interface
can be simplified by removing a callback function and moving the
implementation directly to ui_file.
A new self-test is included. Previously, I think nothing was testing
this code.
Regression tested on x86-64 Fedora 34.
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
gdbtypes.h uses core_addr_eq and core_addr_hash in a weird way: taking
the address of a member and then passing this (as a void*) to these
functions.
It seems better to simply inline the ordinary code here. CORE_ADDR is
a scalar so it can be directly compared, and the identity hash
function seems safe to assume as well.
After this, core_addr_eq and core_addr_hash are unused, so this patch
removes them.
gdb_print_host_address is just a simple wrapper around
fprintf_filtered. However, it is readily replaced in all callers by a
combination of %s and call to host_address_to_string. This also
simplifies the code, so I think it's worthwhile to remove this
function.
Regression tested on x86-64 Fedora 64.
gdb_bfd.c contains most of gdb's BFD-related utility functions.
However, gdb_bfd_errmsg is in utils.c. It seemed better to me to move
this out of util.[ch] and into the BFD-related file instead.
Tested by rebuilding.
This removes the print_spaces helper function, in favor of using the
"*%s" idiom that's already used in many places in gdb. One spot (in
symmisc.c) is changed to use print_spaces_filtered, because the rest
of that function is using filtered output. (This highlights one way
that the printf idiom is better -- this error is harder to make when
using that.)
Regression tested on x86-64 Fedora 34.
I noticed that puts_debug isn't used in the tree. git log tells me
that the last use was removed in 2015:
commit 40e0b27177
Author: Pedro Alves <palves@redhat.com>
Date: Mon Aug 24 15:40:26 2015 +0100
Delete the remaining ROM monitor targets
... and this commit mentions that the code being removed here probably
hadn't worked for 6 years prior to that.
Based on this, I'm removing puts_debug. I don't think it's useful.
Tested by rebuilding.
n_spaces keeps the spaces in a static buffer. If a caller overwrites
these, it may give an incorrect result to a subsequent caller. So,
make the return type const to help avoid this outcome.
This commits adds const versions for the GET and AS_ARRAX_VIEW methods
of gdb_argv. Those methods will be required in the following patch of
the series.
In a bigger series I'm working on, it is convenient to have a
libiberty hash table that manages objects allocated with 'new'. To
make this simpler, I wrote a small template function to serve as a
concise wrapper. Then I realized that this could be reused in a few
other places.
gdb/ChangeLog
2021-05-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (allocate_type_unit_groups_table)
(handle_DW_AT_stmt_list, allocate_dwo_file_hash_table): Use
htab_delete_entry.
(free_line_header_voidp): Remove.
* completer.c
(completion_tracker::completion_hash_entry::deleter): Remove.
(completion_tracker::discard_completions): Use htab_delete_entry.
* utils.h (htab_delete_entry): New template function.
Now that libiberty includes htab_eq_string, we can remove the
identical function from gdb.
gdb/ChangeLog
2021-05-07 Tom Tromey <tom@tromey.com>
* breakpoint.c (ambiguous_names_p): Use htab_eq_string.
* utils.c (streq_hash): Remove.
* utils.h (streq_hash): Don't declare.
* completer.c (completion_tracker::discard_completions): Update
comment.
* ada-lang.c (_initialize_ada_language): Use htab_eq_string.
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...
gdb/ChangeLog
Update copyright year range in copyright header of all GDB files.
After seeing Simon's patch, I thought maybe it was finally time to
remove printfi_filtered and fprintfi_filtered, in favor of using the
"%*s" approach to indenting.
In this patch I took the straightforward approach of always adding a
leading "%*s", even when the format already started with "%s", to
avoid the trickier form of:
printf ("%*s", -indent, string)
Regression tested on x86-64 Fedora 32.
Let me know what you think.
gdb/ChangeLog
2020-12-17 Tom Tromey <tromey@adacore.com>
* gdbtypes.c (print_args, dump_fn_fieldlists, print_cplus_stuff)
(print_gnat_stuff, print_fixed_point_type_info)
(recursive_dump_type): Update.
* go32-nat.c (go32_sysinfo, display_descriptor): Update.
* c-typeprint.c (c_type_print_base_struct_union)
(c_type_print_base_1): Update.
* rust-lang.c (rust_internal_print_type): Update.
* f-typeprint.c (f_language::f_type_print_base): Update.
* utils.h (fprintfi_filtered, printfi_filtered): Remove.
* m2-typeprint.c (m2_record_fields): Update.
* p-typeprint.c (pascal_type_print_base): Update.
* compile/compile-loc2c.c (push, pushf, unary, binary)
(do_compile_dwarf_expr_to_c): Update.
* utils.c (fprintfi_filtered, printfi_filtered): Remove.
This is a generic function which I would like to use in a followup
patch adding support for fixed-point types. So this commit moves it
out of valarith.c into util.c, and makes it non-static.
gdb/ChangeLog:
* utils.h (uinteger_pow): Add declaration.
* utils.c (uinteger_pow): Moved here (without changes)...
* valarith.c (uinteger_pow): ... from here.
This changes gdb/compile to use gdb_argv directly, rather than
manually managing the arrays itself. A few new helpers are added to
gdb_argv.
gdb/ChangeLog
2020-09-23 Tom Tromey <tom@tromey.com>
* utils.h (class gdb_argv): Add move operators.
<append>: New methods.
* compile/compile.c (build_argc_argv): Remove.
(compile_args_argc): Remove.
(compile_args_argv): Change type.
(set_compile_args): Simplify.
(append_args): Remove.
(filter_args): Remove argcp parameter.
(get_args): Return gdb_argv. Simplify.
(compile_to_object): Update.
Introduce the gdb_argv::as_array_view method, as a way to easily pass
the parsed arguments array to a function taking an array view. There is
currently one caller where we can use this (which prompted the
suggestion to implement this method).
Add some selftests for the new method, which at the same time test a
little bit gdb_argv. As far as I know, it's not tested currently.
gdb/ChangeLog:
* utils.h (class gdb_argv) <as_array_view>: New method.
* utils.c (gdb_argv_as_array_view_test): New.
(_initialize_utils): Register selftest.
* maint.c (maintenance_selftest): Use the new method.
Change-Id: I0645037613ed6549aabe60f14a36f3494513b177
I noticed a couple of spots that call malloc_failure, but that don't
need to.
* In xml-support.c, "concat" uses xmalloc, so cannot return NULL.
* In utils.c, "buildargv" also uses xmalloc, so can only return NULL
if the argument is empty.
Tested by the buildbot.
gdb/ChangeLog
2019-12-12 Tom Tromey <tromey@adacore.com>
* xml-support.c (xml_fetch_content_from_file): Don't call
malloc_failure.
* utils.h (class gdb_argv): Remove malloc_failure comment.
* utils.c (gdb_argv::reset): Don't call malloc_failure.
Change-Id: I59483620deb6609ccf2f024d94a29113bb62d1a9
This function is not just slower than xxhash, it is slower than
even libiberty's iterative_hash, so there does not seem to be
a reason for it to exist.
------------------------------------------------------------
Benchmark Time CPU Iterations
------------------------------------------------------------
BM_xxh3 11 ns 11 ns 66127192
BM_xxh32 19 ns 19 ns 36792609
BM_xxh64 16 ns 16 ns 42941328
BM_city32 26 ns 26 ns 27028370
BM_city64 17 ns 17 ns 40472793
BM_iterative_hash 77 ns 77 ns 9088854
BM_bcache_hash 125 ns 125 ns 5599232
gdb/ChangeLog:
2019-12-03 Christian Biesinger <cbiesinger@google.com>
* bcache.c (hash): Remove.
(hash_continue): Remove.
* bcache.h (hash): Remove.
(hash_continue): Remove.
(struct bcache) <ctor>: Update.
* psymtab.c (psymbol_hash): Update.
* stabsread.c (hashname): Update.
* utils.h (fast_hash): Add an argument for a start value,
defaulting to zero.
Change-Id: I107f013eda5fdd3293326b5a206be43155dae0f8
I accidentally pushed the wrong version of the patch for commit
7bb4305982 (where the review
comments were not fixed), and I did a bad conflict resolution
for ccb1ba6229 leading to a
compile error when libxxhash is available. This fixes both
issues.
gdb/ChangeLog:
2019-10-22 Christian Biesinger <cbiesinger@google.com>
* symtab.c (struct demangled_name_entry): Add a constructor.
(free_demangled_name_entry): New function to call the destructor
for demangled_name_entry.
(create_demangled_names_hash): Pass free_demangled_name_entry to
htab_create_alloc.
(symbol_set_names): Call placement new for demangled_name_entry.
* utils.c: No longer include xxhash.h here, now that fast_hash
is inlined in the header.
* utils.h: Instead, include it here.
Change-Id: If776099d39a65a12733d42efcb859feca1b07a39
XXHash is faster than htab_hash_string:
------------------------------------------------------------
Benchmark Time CPU Iterations
------------------------------------------------------------
BM_xxh3 11 ns 11 ns 65887249
BM_xxh32 19 ns 19 ns 36511877
BM_xxh64 16 ns 16 ns 42964585
BM_hash_string 182 ns 182 ns 3853125
BM_iterative_hash 77 ns 77 ns 9087638
Unfortunately, XXH3 is still experimental (see
https://github.com/Cyan4973/xxHash#user-content-new-experimental-hash-algorithm)
However, regular XXH64 is still a lot faster than
htab_hash_string per my benchmark above. I used the
following string for the benchmark:
static constexpr char str[] = "_ZZZL13make_gdb_typeP7gdbarchP10tdesc_typeEN16gdb_type_creator19make_gdb_type_flagsEPK22tdesc_type_with_fieldsE19__PRETTY_FUNCTION__";
htab_hash_string is currently 4.35% + 7.98% (rehashing) of gdb
startup when attaching to Chrome's content_shell.
An additional 5.21% is spent in msymbol_hash, which does not use
this hash function. Unfortunately, since it has to lowercase the
string, it can't use this hash function.
BM_msymbol_hash 52 ns 52 ns 13281495
It may be worth investigating if strlen+XXHash is still faster than
htab_hash_string, which would make it easier to use in more places.
Debian ships xxhash as libxxhash{0,-dev}. Fedora ships it as xxhash-devel.
gdb/ChangeLog:
2019-10-22 Christian Biesinger <cbiesinger@google.com>
* Makefile.in: Link with libxxhash.
* config.in: Regenerate.
* configure: Regenerate.
* configure.ac: Search for libxxhash.
* utils.c (fast_hash): Use xxhash if present.
Change-Id: Icab218388b9f829522ed3977f04301ae6d4fc4ca
Also updates a caller in symtab.c. For now this just calls htab_hash_string
but the next patch will change it to xxhash, if available.
gdb/ChangeLog:
2019-10-22 Christian Biesinger <cbiesinger@google.com>
* utils.h (fast_hash): New function.
* symtab.c (hash_demangled_name_entry): Call new function
fast_hash.
Change-Id: I77cac0d9aa78fc65316a2af449f52edcae72dc9b
