This commit should fix PR gdb/20091, PR gdb/17201, and PR gdb/17071.
Additionally, PR gdb/17199 relates to this area of code, but is more
of a request to refactor some parts of GDB, this commit does not
address that request, but it is probably worth reading that PR when
looking at this commit.
When the current language is C++, and the user places a breakpoint on
a function in a shared library, GDB will currently find two locations
for the breakpoint, one location will be within the function itself as
we would expect, but the other location will be within the PLT table
for the call to the named function. Consider this session:
$ gdb -q /tmp/breakpoint-shlib-func
Reading symbols from /tmp/breakpoint-shlib-func...
(gdb) start
Temporary breakpoint 1 at 0x40112e: file /tmp/breakpoint-shlib-func.cc, line 20.
Starting program: /tmp/breakpoint-shlib-func
Temporary breakpoint 1, main () at /tmp/breakpoint-shlib-func.cc:20
20 int answer = foo ();
(gdb) break foo
Breakpoint 2 at 0x401030 (2 locations)
(gdb) info breakpoints
Num Type Disp Enb Address What
2 breakpoint keep y <MULTIPLE>
2.1 y 0x0000000000401030 <foo()@plt>
2.2 y 0x00007ffff7fc50fd in foo() at /tmp/breakpoint-shlib-func-lib.cc:20
This is not the expected behaviour. If we compile the same test using
a C compiler then we see this:
(gdb) break foo
Breakpoint 2 at 0x7ffff7fc50fd: file /tmp/breakpoint-shlib-func-c-lib.c, line 20.
(gdb) info breakpoints
Num Type Disp Enb Address What
2 breakpoint keep y 0x00007ffff7fc50fd in foo at /tmp/breakpoint-shlib-func-c-lib.c:20
Here's what's happening. When GDB parses the symbols in the main
executable and the shared library we see a number of different symbols
for foo, and use these to create entries in GDB's msymbol table:
- In the main executable we see a symbol 'foo@plt' that points at
the plt entry for foo, from this we add two entries into GDB's
msymbol table, one called 'foo@plt' which points at the plt entry
and has type mst_text, then we create a second symbol, this time
called 'foo' with type mst_solib_trampoline which also points at
the plt entry,
- Then, when the shared library is loaded we see another symbol
called 'foo', this one points at the actual implementation in the
shared library. This time GDB creates a msymbol called 'foo' with
type mst_text that points at the implementation.
This means that GDB creates 3 msymbols to represent the 2 symbols
found in the executable and shared library.
When the user creates a breakpoint on 'foo' GDB eventually ends up in
search_minsyms_for_name (linespec.c), this function then calls
iterate_over_minimal_symbols passing in the name we are looking for
wrapped in a lookup_name_info object.
In iterate_over_minimal_symbols we iterate over two hash tables (using
the name we're looking for as the hash key), first we walk the hash
table of symbol linkage names, then we walk the hash table of
demangled symbol names.
When the language is C++ the symbols for 'foo' will all have been
mangled, as a result, in this case, the iteration of the linkage name
hash table will find no matching results.
However, when we walk the demangled hash table we do find some
results. In order to match symbol names, GDB obtains a symbol name
matching function by calling the get_symbol_name_matcher method on the
language_defn class. For C++, in this case, the matching function we
use is cp_fq_symbol_name_matches, which delegates the work to
strncmp_iw_with_mode with mode strncmp_iw_mode::MATCH_PARAMS and
language set to language_cplus.
The strncmp_iw_mode::MATCH_PARAMS mode means that strncmp_iw_mode will
skip any parameters in the demangled symbol name when checking for a
match, e.g. 'foo' will match the demangled name 'foo()'. The way this
is done is that the strings are matched character by character, but,
once the string we are looking for ('foo' here) is exhausted, if we
are looking at '(' then we consider the match a success.
Lets consider the 3 symbols GDB created. If the function declaration
is 'void foo ()' then from the main executable we added symbols
'_Z3foov@plt' and '_Z3foov', while from the shared library we added
another symbol call '_Z3foov'. When these are demangled they become
'foo()@plt', 'foo()', and 'foo()' respectively.
Now, the '_Z3foov' symbol from the main executable has the type
mst_solib_trampoline, and in search_minsyms_for_name, we search for
any symbols of type mst_solib_trampoline and filter these out of the
results.
However, the '_Z3foov@plt' symbol (from the main executable), and the
'_Z3foov' symbol (from the shared library) both have type mst_text.
During the demangled name matching, due to the use of MATCH_PARAMS
mode, we stop the comparison as soon as we hit a '(' in the demangled
name. And so, '_Z3foov@plt', which demangles to 'foo()@plt' matches
'foo', and '_Z3foov', which demangles to 'foo()' also matches 'foo'.
By contrast, for C, there are no demangled hash table entries to be
iterated over (in iterate_over_minimal_symbols), we only consider the
linkage name symbols which are 'foo@plt' and 'foo'. The plain 'foo'
symbol obviously matches when we are looking for 'foo', but in this
case the 'foo@plt' will not match due to the '@plt' suffix.
And so, when the user asks for a breakpoint in 'foo', and the language
is C, search_minsyms_for_name, returns a single msymbol, the mst_text
symbol for foo in the shared library, while, when the language is C++,
we get two results, '_Z3foov' for the shared library function, and
'_Z3foov@plt' for the plt entry in the main executable.
I propose to fix this in strncmp_iw_with_mode. When the mode is
MATCH_PARAMS, instead of stopping at a '(' and assuming the match is a
success, GDB will instead search forward for the matching, closing,
')', effectively skipping the parameter list, and then resume
matching. Thus, when comparing 'foo' to 'foo()@plt' GDB will
effectively compare against 'foo@plt' (skipping the parameter list),
and the match will fail, just as it does when the language is C.
There is one slight complication, which is revealed by the test
gdb.linespec/cpcompletion.exp, when searching for the symbol of a
const member function, the demangled symbol will have 'const' at the
end of its name, e.g.:
struct_with_const_overload::const_overload_fn() const
Previously, the matching would stop at the '(' character, but after my
change the whole '()' is skipped, and the match resumes. As a result,
the 'const' modifier results in a failure to match, when previously
GDB would have found a match.
To work around this issue, in strncmp_iw_with_mode, when mode is
MATCH_PARAMS, after skipping the parameter list, if the next character
is '@' then we assume we are looking at something like '@plt' and
return a value indicating the match failed, otherwise, we return a
value indicating the match succeeded, this allows things like 'const'
to be skipped.
With these changes in place I now see GDB correctly setting a
breakpoint only at the implementation of 'foo' in the shared library.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=20091
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=17201
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=17071
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=17199
Tested-By: Bruno Larsen <blarsen@redhat.com>
Approved-By: Simon Marchi <simon.marchi@efficios.com>
gdbsupport/errors.h declares perror_with_name and leaves the
implementation to the clients.
However gdb and gdbserver's implementations are essentially the
same, resulting in unnecessary code duplication.
Fix this by implementing perror_with_name in gdbsupport. Add an
optional parameter for specifying the errno used to generate the
error message.
Also move the implementation of perror_string to gdbsupport since
perror_with_name requires it.
Approved-By: Tom Tromey <tom@tromey.com>
When an assert triggers in tui mode the output is not great, the
internal backtrace that is generated is printed directly to the file
descriptor for gdb_stderr, and, as a result, does not currently format
itself correctly - the output uses only '\n' at the end of each line,
and so, when the terminal is in raw mode, the cursor does not return
to the start of each line after the '\n'.
This is mostly fixable, we could update bt-utils.c to use '\r\n'
instead of just '\n', and this would fix most of the problems. The
one we can't easily fix is if/when GDB is built to use execinfo
instead of libbacktrace, in this case we use backtrace_symbols_fd to
print the symbols, and this function only uses '\n' as the line
terminator. Fixing this would require switching to backtrace_symbols,
but that API uses malloc, which is something we're trying to
avoid (this code is called when GDB hits an error, so ideally we don't
want to rely on malloc).
However, the execinfo code is only used when libbacktrace is not
available (or the user specifically disables libbacktrace) so maybe we
can ignore that problem...
... but there is another problem. When the backtrace is printed in
raw mode, it is possible that the backtrace fills the screen. With
the terminal in raw mode we don't have the ability to scroll back,
which means we loose some of the backtrace, which isn't ideal.
In this commit I propose that we should disable tui mode whenever we
handle a fatal signal, or when we hit the internal error code
path (e.g. when an assert triggers). With this done then we don't
need to update the bt-utils.c code, and the execinfo version of the
code (using backtrace_symbols_fd) works just fine. We also get the
ability to scroll back to view the error message and all of the
backtrace, assuming the users terminal supports scrolling back.
The only downside I see with this change is if the tui_disable call
itself causes an error for some reason, or, if we handle a single at a
time when it is not safe to call tui_disable, in these cases the extra
tui_disable call might cause GDB to loose the original error.
However, I think (just from personal experience) that the above two
issues are pretty rare and the benefits from this change far out
weighs the possible drawbacks.
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>
Currently, every internal_error call must be passed __FILE__/__LINE__
explicitly, like:
internal_error (__FILE__, __LINE__, "foo %d", var);
The need to pass in explicit __FILE__/__LINE__ is there probably
because the function predates widespread and portable variadic macros
availability. We can use variadic macros nowadays, and in fact, we
already use them in several places, including the related
gdb_assert_not_reached.
So this patch renames the internal_error function to something else,
and then reimplements internal_error as a variadic macro that expands
__FILE__/__LINE__ itself.
The result is that we now should call internal_error like so:
internal_error ("foo %d", var);
Likewise for internal_warning.
The patch adjusts all calls sites. 99% of the adjustments were done
with a perl/sed script.
The non-mechanical changes are in gdbsupport/errors.h,
gdbsupport/gdb_assert.h, and gdb/gdbarch.py.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Change-Id: Ia6f372c11550ca876829e8fd85048f4502bdcf06
This patch removes ui_register_input_event_handler and
ui_unregister_input_event_handler, replacing them with methods on
'ui'. It also changes gdb to use these methods everywhere, rather
than sometimes reaching in to the ui to manage the file descriptor
directly.
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.
PR cli/17151 points out that "set height 1" has pathological behavior
in gdb. What I see is that gdb will endlessly print the pagination
prompt. This patch takes a simple and expedient approach to a fix:
pretend that the height is really 2.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=17151
PR cli/20741 points out that when pagination is disabled, this also
disabled word wrapping. However, the manual documents that these
settings are separate -- if you intend to disable the wrapping, you
must use "set width unlimited".
This patch fixes the bug by letting the pagination-disabled case fall
through to the code that also handles word-wrapping.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=20741
While working on a different patch, I triggered an assertion from the
initialize_current_architecture code, specifically from one of
the *_gdbarch_init functions in a *-tdep.c file. This exposes a
couple of issues with GDB.
This is easy enough to reproduce by adding 'gdb_assert (false)' into a
suitable function. For example, I added a line into i386_gdbarch_init
and can see the following issue.
I start GDB and immediately hit the assert, the output is as you'd
expect, except for the very last line:
$ ./gdb/gdb --data-directory ./gdb/data-directory/
../../src.dev-1/gdb/i386-tdep.c:8455: internal-error: i386_gdbarch_init: Assertion `false' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
----- Backtrace -----
... snip ...
---------------------
../../src.dev-1/gdb/i386-tdep.c:8455: internal-error: i386_gdbarch_init: Assertion `false' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) ../../src.dev-1/gdb/ser-event.c:212:16: runtime error: member access within null pointer of type 'struct serial'
Something goes wrong when we try to query the user. Note, I
configured GDB with --enable-ubsan, I suspect that without this the
above "error" would actually just be a crash.
The backtrace from ser-event.c:212 looks like this:
(gdb) bt 10
#0 serial_event_clear (event=0x675c020) at ../../src/gdb/ser-event.c:212
#1 0x0000000000769456 in invoke_async_signal_handlers () at ../../src/gdb/async-event.c:211
#2 0x000000000295049b in gdb_do_one_event () at ../../src/gdbsupport/event-loop.cc:194
#3 0x0000000001f015f8 in gdb_readline_wrapper (
prompt=0x67135c0 "../../src/gdb/i386-tdep.c:8455: internal-error: i386_gdbarch_init: Assertion `false' failed.\nA problem internal to GDB has been detected,\nfurther debugging may prove unreliable.\nQuit this debugg"...)
at ../../src/gdb/top.c:1141
#4 0x0000000002118b64 in defaulted_query(const char *, char, typedef __va_list_tag __va_list_tag *) (
ctlstr=0x2e4eb68 "%s\nQuit this debugging session? ", defchar=0 '\000', args=0x7fffffffa6e0)
at ../../src/gdb/utils.c:934
#5 0x0000000002118f72 in query (ctlstr=0x2e4eb68 "%s\nQuit this debugging session? ")
at ../../src/gdb/utils.c:1026
#6 0x00000000021170f6 in internal_vproblem(internal_problem *, const char *, int, const char *, typedef __va_list_tag __va_list_tag *) (problem=0x6107bc0 <internal_error_problem>, file=0x2b976c8 "../../src/gdb/i386-tdep.c",
line=8455, fmt=0x2b96d7f "%s: Assertion `%s' failed.", ap=0x7fffffffa8e8) at ../../src/gdb/utils.c:417
#7 0x00000000021175a0 in internal_verror (file=0x2b976c8 "../../src/gdb/i386-tdep.c", line=8455,
fmt=0x2b96d7f "%s: Assertion `%s' failed.", ap=0x7fffffffa8e8) at ../../src/gdb/utils.c:485
#8 0x00000000029503b3 in internal_error (file=0x2b976c8 "../../src/gdb/i386-tdep.c", line=8455,
fmt=0x2b96d7f "%s: Assertion `%s' failed.") at ../../src/gdbsupport/errors.cc:55
#9 0x000000000122d5b6 in i386_gdbarch_init (info=..., arches=0x0) at ../../src/gdb/i386-tdep.c:8455
(More stack frames follow...)
It turns out that the problem is that the async event handler
mechanism has been invoked, but this has not yet been initialized.
If we look at gdb_init (in gdb/top.c) we can indeed see the call to
gdb_init_signals is after the call to initialize_current_architecture.
If I reorder the calls, moving gdb_init_signals earlier, then the
initial error is resolved, however, things are still broken. I now
see the same "Quit this debugging session? (y or n)" prompt, but when
I provide an answer and press return GDB immediately crashes.
So what's going on now? The next problem is that the call_readline
field within the current_ui structure is not initialized, and this
callback is invoked to process the reply I entered.
The problem is that call_readline is setup as a result of calling
set_top_level_interpreter, which is called from captured_main_1.
Unfortunately, set_top_level_interpreter is called after gdb_init is
called.
I wondered how to solve this problem for a while, however, I don't
know if there's an easy "just reorder some lines" solution here.
Looking through captured_main_1 there seems to be a bunch of
dependencies between printing various things, parsing config files,
and setting up the interpreter. I'm sure there is a solution hiding
in there somewhere.... I'm just not sure I want to spend any longer
looking for it.
So.
I propose a simpler solution, more of a hack/work-around. In utils.c
we already have a function filtered_printing_initialized, this is
checked in a few places within internal_vproblem. In some of these
cases the call gates whether or not GDB will query the user.
My proposal is to add a new readline_initialized function, which
checks if the current_ui has had readline initialized yet. If this is
not the case then we should not attempt to query the user.
After this change GDB prints the error message, the backtrace, and
then aborts (including dumping core). This actually seems pretty sane
as, if GDB has not yet made it through the initialization then it
doesn't make much sense to allow the user to say "no, I don't want to
quit the debug session" (I think).
I noticed that GDB will display URLs in a few spots. This changes
them to be styled. Originally I thought I'd introduce a new "url"
style, but there aren't many places to use this, so I just reused
filename styling instead. This patch also changes the debuginfod URL
list to be printed one URL per line. I think this is probably a bit
easier to read.
Pedro pointed out that gdb worker threads should not react to quits.
While I don't think that the new DWARF reader can call QUIT from a
worker thread (and I don't think the existing minsym threading code
can either), it seems safest to address this before checking in the
new code. This patch arranges for the QUIT macro to only work on the
main thread.
Various spots in gdb currently know about the wrap buffer, and so are
careful to call wrap_here to be certain that all output has been
flushed.
Now that the pager is just an ordinary stream, this isn't needed, and
a simple call to gdb_flush is enough.
Similarly, there are places where gdb prints to gdb_stderr, but first
flushes gdb_stdout. stderr_file already flushes gdb_stdout, so these
aren't needed.
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
When the pager is rewritten as a ui_file, gdb will still need a way to
bypass the filtering. After examining a few approaches, I chose this
patch, which adds a puts_unfiltered method to ui_file. For most
implementations of ui_file, this will just delegate to puts. This
patch also switches printf_unfiltered to use the new method.
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.)
Currently, timestamps for logging are done by looking for the use of
gdb_stdlog in vfprintf_unfiltered. This seems potentially buggy, in
that during logging or other redirects (like execute_fn_to_ui_file) we
might have gdb_stdout==gdb_stdlog and so, conceivably, wind up with
timestamps in a log when they were not desired.
It seems better, instead, for timestamps to be a property of the
ui_file itself.
This patch changes gdb to use the new timestamped_file for gdb_stdlog
where appropriate, and removes the special case from
vfprintf_unfiltered.
Note that this may somewhat change the output in some cases -- in
particular, when going through execute_fn_to_ui_file (or the _string
variant), timestamps won't be emitted. This could be fixed in those
functions, but it wasn't clear to me whether this is really desirable.
Note also that this changes the TUI to send gdb_stdlog to gdb_stderr.
I imagine that the previous use of gdb_stdout here was inadvertent.
(And in any case it probably doesn't matter.)
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.
This patch attempts to make a start at adding unit tests for
strncmp_iw_with_mode. While there is quite a bit of testing
of this function in other tests, these are currently end-to-end
tests.
This patch attempts to cover the basics of string matching, white
space, C++ ABI tags, and several other topics. However, one area
that is ostensibly missing is testing the `match_for_lcd' feature.
This is otherwise tested as part of our end-to-end DejaGNU-based
testing.
A have had situation where a unfiltered output (done using
fputs_unfiltered) ended up triggering pagination. The backtrace for this was:
...
#24 0x000055839377ee4e in check_async_event_handlers () at ../../gdb/async-event.c:335
#25 0x0000558394b67b57 in gdb_do_one_event () at ../../gdbsupport/event-loop.cc:216
#26 0x0000558394587454 in gdb_readline_wrapper (prompt=0x7ffd907712d0 "--Type <RET> for more, q to quit, c to continue without paging--") at ../../gdb/top.c:1148
#27 0x0000558394707270 in prompt_for_continue () at ../../gdb/utils.c:1438
#28 0x00005583947088b3 in fputs_maybe_filtered (linebuffer=0x60c0000f4000 " [...quite big message...]", stream=0x60300028e9d0, filter=0) at ../../gdb/utils.c:1752
#29 0x0000558394708e57 in fputs_unfiltered (linebuffer=0x60c0000f4000 " [...quite big message...]", stream=0x60300028e9d0) at ../../gdb/utils.c:1811
...
This comes from what appears to be a oversight in fputs_maybe_filtered. This
function has a FILTER parameter which if true makes the function pause after
every screenful (i.e. triggers pagination).
The filter parameter is correctly used to guard the first place where
prompt_for_continue. There is a second place in the function which can call
prompt_for_continue, but is currently unguarded. I believe that this is an
oversight, this patch fixes that.
Tested on Linux-x86_64, no regression observed.
Change-Id: Iad8ffd50a87cf20077500878e2564b5a7dc81ece
I noticed that host_hex_value is redundant, because gdbsupport already
has fromhex. This patch removes the former in favor of the latter.
Regression tested on x86-64 Fedora 34.
This removes the global wrap_here function, so that future calls
cannot be introduced. Instead, all callers must use the method on the
appropriate ui_file.
This temporarily moves the implementation of this method to utils.c.
This will change once the remaining patches to untangle the pager have
been written.
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.
A common pattern for string_file is to want to move out the internal
string buffer, because it is the result of the computation that we want
to return. It is the reason why string_file::string returns a non-const
reference, as explained in the comment. I think it would make sense to
have a dedicated method for that instead and make string_file::string
return a const reference.
This allows removing the explicit std::move in the typical case. Note
that compile_program::compute was missing a move, meaning that the
resulting string was copied. With the new version, it's not possible to
forget to move.
Change-Id: Ieaefa35b73daa7930b2f3a26988b6e3b4121bb79
In an earlier version of the pager rewrite series, it was important to
audit unfiltered output calls to see which were truly necessary.
This is no longer necessary, but it still seems like a decent cleanup
to change calls to avoid explicitly passing gdb_stdout. That is,
rather than using something like fprintf_unfiltered with gdb_stdout,
the code ought to use plain printf_unfiltered instead.
This patch makes this change. I went ahead and converted all the
_filtered calls I could find, as well, for the same clarity.
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.
The patch to fix paging with redirection caused a regression in the
internal AdaCore test suite. The problem occurs when running an MI
command from the CLI using interpreter-exec, when paging is enabled.
This scenario isn't covered by the current test suite, so this patch
includes a new test.
The problem is that, in this situation, MI does:
fputs_unfiltered (strcmp (context->command, "target-select") == 0
? "^connected" : "^done", mi->raw_stdout);
Here raw_stdout is a stdio_file wrapping stdout, so the pager thinks
that it is ok to buffer the output. However, in this setup, it isn't
ok, and flushing the wrap buffer doesn't really work properly. Also,
MI next does:
mi_out_put (uiout, mi->raw_stdout);
... but this uses ui_file::write, which also doesn't flush the wrap
buffer.
I think all this will be fixed by the pager rewrite series I'm working
on. However, in the meantime, adding the old gdb_stdout check back to
the pager fixes this problem.
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.
I noticed yesterday that if gdb output is redirected to a file, the
pager will still be active. This is irritating, because the output
isn't actually visible -- just the pager prompt. Looking in bugzilla,
I found that this had been filed 17 years ago, as PR cli/8798.
This patch fixes the bug. It changes the pagination code to query the
particular ui-file to see if paging is allowable. The ui-file
implementations are changed so that only the stdout implementation and
a tee (where one sub-file is stdout) can page.
Regression tested on x86-64 Fedora 34.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=8798
