I noticed that nat/windows-nat.c checks __USEWIDE, but nothing sets it
there -- I forgot to copy over the definition when making this file.
This patch tries to fix the problem. I don't have a Cygwin setup, so
I don't know whether this is sufficient, but it's probably necessary.
Pedro Alves warned me that there is a race in
gdb.dwarf2/calling-convention.exp making the test sometimes fail on his
setup. This can be reliably reproduced using :
make check-read1 TESTS="gdb.dwarf2/calling-convention.exp"
The relevant part of the gdb.log file is:
return 35
Function 'foo' does not follow the target calling convention.
If you continue, setting the return value will probably lead to unpredictable behaviors.
Make foo return now? (y or n) PASS: gdb.dwarf2/calling-convention.exp: return 35
n
Not confirmed
(gdb) FAIL: gdb.dwarf2/calling-convention.exp: finish
The issue is that when doing the test for "return 35", the DejaGnu test
sends "n" (to tell GDB not to perform the return action) but never
consumes the "Not confirmed" acknowledgment sent by GDB. Later, when
trying to do the next test, DejaGnu tries to match the leftover output
from the "return" test. As this output is not expected, the test fails.
Fix by using gdb_test to send the "n" answer and match the confirmation
and consume all output to the prompt.
Also do minor adjustments to the main regex:
- Remove the leading ".*" which is not required.
- Ensure that the "?" from the question is properly escaped.
Tested on x86_64-gnu-linux, using
- make check TESTS="gdb.dwarf2/calling-convention.exp"
- make check-read1 TESTS="gdb.dwarf2/calling-convention.exp"
- make check-readmore TESTS="gdb.dwarf2/calling-convention.exp"
Co-authored-by: Pedro Alves <pedro@palves.net>
Change-Id: I42858b13db2cbd623c5c1739de65ad423e0c0938
Currently, one use of target_waitstatus yields a warning:
target/waitstatus.h: In function 'void stop_all_threads()':
target/waitstatus.h:175:13: warning: 'ws.target_waitstatus::m_value' may be used uninitialized in this function [-Wmaybe-uninitialized]
175 | m_value = other.m_value;
| ~~~~~~~~^~~~~~~~~~~~~~~
This patch silences the warning. I tried the "volatile member"
approach that was used for gdb::optional, but that didn't work, so
this patch simply initializes the member.
Internally at AdaCore, we recently started testing a 64-bit gdb
debugging 32-bit processes. This failed with gdb head, but not with
gdb 11.
The tests fail like this:
Starting program: [...].exe
warning: Could not load shared library symbols for WOW64_IMAGE_SECTION.
Do you need "set solib-search-path" or "set sysroot"?
warning: Could not load shared library symbols for WOW64_IMAGE_SECTION.
Do you need "set solib-search-path" or "set sysroot"?
warning: Could not load shared library symbols for NOT_AN_IMAGE.
Do you need "set solib-search-path" or "set sysroot"?
warning: Could not load shared library symbols for NOT_AN_IMAGE.
Do you need "set solib-search-path" or "set sysroot"?
After some debugging and bisecting, to my surprise the bug was
introduced by commit 183be222 ("gdb, gdbserver: make target_waitstatus
safe").
The problem occurs in handle_exception. Previously the code did:
- ourstatus->kind = TARGET_WAITKIND_STOPPED;
[...]
case EXCEPTION_BREAKPOINT:
[...]
- ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
[...]
/* FALLTHROUGH */
case STATUS_WX86_BREAKPOINT:
DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_BREAKPOINT");
- ourstatus->value.sig = GDB_SIGNAL_TRAP;
[...]
- last_sig = ourstatus->value.sig;
However, in the new code, the fallthrough case does:
+ ourstatus->set_stopped (GDB_SIGNAL_TRAP);
... which changes the 'kind' in 'ourstatus' after falling through.
This patch rearranges the 'last_sig' setting to more closely match
what was done before (this is probably not strictly needed but also
seemed harmless), and removes the fall-through in the
'ignore_first_breakpoint' case when __x86_64__ is defined.
This slightly reorganizes the Python events documentation. It hoists
the "ThreadEvent" text out of the list of events, where it seemed to
be misplaced. It tidies the formatting a little bit (adding some
vertical space for easier reading in info), fixes a typo, adds some
missing commas, and fixes an incorrect reference to NewInferiorEvent.
Building with clang++-14, I see:
CXX dwarf2/cooked-index.o
In file included from /home/smarchi/src/binutils-gdb/gdb/dwarf2/cooked-index.c:21:
/home/smarchi/src/binutils-gdb/gdb/dwarf2/cooked-index.h:172:12: error: explicitly defaulted move constructor is implicitly deleted [-Werror,-Wdefaulted-function-deleted]
explicit cooked_index (cooked_index &&other) = default;
^
/home/smarchi/src/binutils-gdb/gdb/dwarf2/cooked-index.h:225:16: note: move constructor of 'cooked_index' is implicitly deleted because field 'm_storage' has a deleted move constructor
auto_obstack m_storage;
^
/home/smarchi/src/binutils-gdb/gdb/../gdbsupport/gdb_obstack.h:128:28: note: 'auto_obstack' has been explicitly marked deleted here
DISABLE_COPY_AND_ASSIGN (auto_obstack);
^
In file included from /home/smarchi/src/binutils-gdb/gdb/dwarf2/cooked-index.c:21:
/home/smarchi/src/binutils-gdb/gdb/dwarf2/cooked-index.h:174:17: error: explicitly defaulted move assignment operator is implicitly deleted [-Werror,-Wdefaulted-function-deleted]
cooked_index &operator= (cooked_index &&other) = default;
^
/home/smarchi/src/binutils-gdb/gdb/dwarf2/cooked-index.h:225:16: note: move assignment operator of 'cooked_index' is implicitly deleted because field 'm_storage' has a deleted move assignment operator
auto_obstack m_storage;
^
/home/smarchi/src/binutils-gdb/gdb/../gdbsupport/gdb_obstack.h:128:3: note: 'operator=' has been explicitly marked deleted here
DISABLE_COPY_AND_ASSIGN (auto_obstack);
^
/home/smarchi/src/binutils-gdb/gdb/../include/ansidecl.h:425:8: note: expanded from macro 'DISABLE_COPY_AND_ASSIGN'
void operator= (const TYPE &) = delete
^
We explicitly make cooked_index have a default move constructor and
move assignment operator. But it doesn't actually happen because
cooked_index has a field of type auto_obstack, which isn't movable.
We don't actually need cooked_index to be movable at the moment, so
remove those lines.
Change-Id: Ifc1fe3d7d67e3ae1a14363d6c1869936fe80b0a2
Currently, the configure check for std::thread relies on pthreads
existing. However, this means that if std::thread is implemented for
a non-pthreads host, then the check will yield the wrong answer. This
happened in AdaCore internal builds. Here, we have this GCC patch:
https://gcc.gnu.org/legacy-ml/gcc-patches/2019-06/msg01840.html
... which adds mingw support to GCC's gthreads implementation, and
also to std::thread.
This configure change fixes this problem and enables threading for
gdb.
When I build gdb with gcc 8.3, there exist the following build errors,
rename the typedef to task_t to fix them.
CXX thread-pool.o
In file included from /home/loongson/gdb.git/gdbsupport/thread-pool.cc:21:
/home/loongson/gdb.git/gdbsupport/../gdbsupport/thread-pool.h: In member function ‘std::future<void> gdb::thread_pool::post_task(std::function<void()>&&)’:
/home/loongson/gdb.git/gdbsupport/../gdbsupport/thread-pool.h:69:44: error: declaration of ‘task’ shadows a previous local [-Werror=shadow=local]
std::packaged_task<void ()> task (std::move (func));
^~~~
/home/loongson/gdb.git/gdbsupport/../gdbsupport/thread-pool.h:102:39: note: shadowed declaration is here
typedef std::packaged_task<void ()> task;
^~~~
/home/loongson/gdb.git/gdbsupport/../gdbsupport/thread-pool.h: In member function ‘std::future<_Res> gdb::thread_pool::post_task(std::function<T()>&&)’:
/home/loongson/gdb.git/gdbsupport/../gdbsupport/thread-pool.h:80:41: error: declaration of ‘task’ shadows a previous local [-Werror=shadow=local]
std::packaged_task<T ()> task (std::move (func));
^~~~
/home/loongson/gdb.git/gdbsupport/../gdbsupport/thread-pool.h:102:39: note: shadowed declaration is here
typedef std::packaged_task<void ()> task;
^~~~
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
On openSUSE Leap 15.3, mpx support has been disabled for m32, so I run into:
...
(gdb) run ^M
Starting program: outputs/gdb.arch/i386-mpx/i386-mpx ^M
[Thread debugging using libthread_db enabled]^M
Using host libthread_db library "/lib64/libthread_db.so.1".^M
No MPX support^M
...
and eventually into all sort of fails in this and other mpx test-cases.
Fix this by detecting the "No MPX support" message in have_mpx.
Tested on x86_64-linux with target boards unix and unix/-m32.
Before the change tc-m68k maintained a list of seen labels.
Alignment check traversed label list to resolve symbol to label.
This caused quadratic slowdown as each symbol was checked against
each label. Worst affected files are the ones built with debugging
enabled as DWARF generates many labels.
The change embeds auxiliary label information right into symbol using
TC_SYMFIELD_TYPE.
Before the change test from PR 29058 did not finish in 10 minutes. After
the change it finishes in 2 seconds.
gas/ChangeLog:
PR 29058
* config/tc-m68k.h (TC_SYMFIELD_TYPE): define as m68k_tc_sy.
* config/tc-m68k.c (m68k_frob_label): Use TC_SYMFIELD_TYPE to
store label information.
Fix this error when building with clang++-14:
CXX complaints.o
/home/smarchi/src/binutils-gdb/gdb/complaints.c:130:65: error: format string is not a string literal [-Werror,-Wformat-nonliteral]
g_complaint_interceptor->m_complaints.insert (string_vprintf (fmt, args));
^~~
Change-Id: I0ef11f970510eb8638d1651fa0d5eeecd6a9d31a
Building with clang++-14, I see:
CXX mips-tdep.o
/home/smarchi/src/binutils-gdb/gdb/mips-tdep.c:453:12: error: use of bitwise '|' with boolean operands [-Werror,-Wbitwise-instead-of-logical]
return !(MSYMBOL_TARGET_FLAG_MIPS16 (msym)
~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/smarchi/src/binutils-gdb/gdb/mips-tdep.h:54:2: note: expanded from macro 'MSYMBOL_TARGET_FLAG_MIPS16'
(sym)->target_flag_1 ()
^
/home/smarchi/src/binutils-gdb/gdb/mips-tdep.c:453:12: note: cast one or both operands to int to silence this warning
/home/smarchi/src/binutils-gdb/gdb/mips-tdep.h:54:2: note: expanded from macro 'MSYMBOL_TARGET_FLAG_MIPS16'
(sym)->target_flag_1 ()
^
That's since commit e165fcef1e ("gdb: remove MSYMBOL_TARGET_FLAG_{1,2}
macros"). Fix this by using the boolean || rather than the bitwise |,
since the new methods return bool values. No change in behavior
expected.
Change-Id: Ia82664135aa25db64c29c92f5c1141859d345bf7
Tromey noticed that intrusive_list_node leaves its data members
public, which seems sub-optimal.
This commit makes intrusive_list_node's data fields private.
intrusive_list_iterator, intrusive_list_reverse_iterator, and
intrusive_list do need to access the fields, so they are made friends.
Change-Id: Ia8b306b40344cc218d423c8dfb8355207a612ac5
Now that Ada is able to parse & print 0xffffffffffffffff (2^64-1) in
hex, move it to the else branch like most other languages.
Change-Id: Ib305f6bb2b6b230a1190ea783b245b865821094c
On irc, Pedro pointed out that Ada couldn't properly handle
0xffffffffffffffff. This used to work, but is a regression due to
some patches I wrote in the Ada lexer. This patch fixes the bug.
Reading a simple file compiled with :
$ gcc -DONE=1 -gdwarf-4 -g3 test.c
$ gcc --version
gcc (Ubuntu 9.4.0-1ubuntu1~20.04) 9.4.0
I get:
Reading symbols from /tmp/cwd/a.out...
/home/smarchi/src/binutils-gdb/gdb/dwarf2/cooked-index.c:332:11: runtime error: null pointer passed as argument 2, which is declared to never be null
It looks like even if the size is 0 (the size of the `entries` vector is
0), we shouldn't be passing a NULL pointer to memcpy. And
`entries.data ()` returns NULL.
Fix that by using std::vector::insert to insert the items of entries
into m_entries. I haven't checked, but it should essentially compile
down to a memcpy, since the vector elements are trivially copyiable.
Change-Id: I75f1c901e9b522e42e89eb5936e2c70d68eb21e5
Change this field to an std::vector to facilitate memory management.
Since the linetable_entry array is copied into the symtab resulting from
the subfile, it is possible to change it without changing how symtab
stores the linetable entries (which would be a much larger change).
There is a small change in buildsym_compunit::record_line to avoid
accessing a now invalid linetable_entry. Before this patch, we keep a
pointer to the last linetable entry, pop it from the vector, and then
read last->line. It works with the manually-maintained array, but since
we now use std::vector::pop_back, I am afraid that it could be flagged
as an invalid access by the various static / dynamic analysis tools to
access the linetable_entry object after popping it from the vector.
Instead, record just the line number in an optional and use it.
There are substantial changes in xcoffread.c that simplify the code, but
I can't test them. I was hesitant to do this change because of that,
but I decided to send it anyway. I don't think that an almost dead
platform should hold back improving the code in the common parts of GDB.
The changes in xcoffread.c are:
- Make arrange_linetable "arrange" the linetable passed as a parameter,
instead of returning possibly a new one, possibly the same one.
- In the "Process main file's line numbers.", I'm not too sure what
happens. We get the lintable from "main_subfile", "arrange" it, but
then assign the result to the current subfile, obtained with
get_current_subfile. I assume that the current subfile is also the
main one, so now I just call arrange_linetable on the main subfile's
line table.
- Remove that weird "Useless if!!!" FIXME comment. It's been there
forever, but the "if" is still there, so I guess the "if" can stay
there.
Change-Id: I11799006fd85189e8cf5bd3a168f8f38c2c27a80
Reduce manual memory management and make the code a bit easier to read.
This helps me a bit in the following patch.
I don't have a way to test this, it's best-effort.
Change-Id: I64af9cd756311deabc6cd95e701dfb21234a40a5
Change subfile::name to be a string, for easier memory management.
Change buildsym_compunit::m_comp_dir as well, since we move one in to
the other at some point in patch_subfile_names, so it's easier to do
both at the same time. There are various NULL checks for both fields
currently, replace them with empty checks, I think it ends up
equivalent.
I can't test the change in xcoffread.c, it's best-effort.
Change-Id: I62b5fb08b2089e096768a090627ac7617e90a016
Allocate struct subfile with new, initialize its fields instead of
memset-ing it to 0. Use a unique_ptr for the window after a subfile has
been allocated but before it is linked in the buildsym_compunit's list
of subfile (and therefore owned by the buildsym_compunit.
I can't test the change in xcoffread.c, it's best-effort. I couldn't
find where subfiles are freed in that file, I assume they were
intentionally (or not) leaked.
Change-Id: Ib3b6877de31b7e65bc466682f08dbf5840225f24
When building with -std=c++11, I get:
CXX dwarf2/read.o
/home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c: In function ‘void dwarf2_build_psymtabs_hard(dwarf2_per_objfile*)’:
/home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:7130:23: error: expected type-specifier before ‘typeof’
7130 | using iter_type = typeof (per_bfd->all_comp_units.begin ());
| ^~~~~~
This is because typeof is a GNU extension. Use C++'s decltype keyword
instead.
Change-Id: Ieca2e8d25e50f71dc6c615a405a972a54de3ef14
When building with -std=c++11, I get:
In file included from /home/smarchi/src/binutils-gdb/gdb/unittests/parallel-for-selftests.c:22: /home/smarchi/src/binutils-gdb/gdb/../gdbsupport/parallel-for.h:134:10: error: ‘result_of_t’ is not a member of ‘std’; did you mean ‘result_of’?
134 | std::result_of_t<RangeFunction (RandomIt, RandomIt)>
| ^~~~~~~~~~~
| result_of
This is because result_of_t has been introduced in C++14. Use the
equivalent result_of<...>::type instead.
result_of and result_of_t have been removed in C++20 though, so I think
we'll need some patches eventually to make the code use invoke_result
instead, depending on the C++ version.
Change-Id: I4817f361c0ebcdd4b32976898fc368bb302b61b9
Now that the psymtab reader has been removed, the
dwarf2_per_cu_data::v union is no longer needed. Instead, we can
simply move the members from dwarf2_per_cu_quick_data into
dwarf2_per_cu_data and remove the "quick" object entirely.
This patch finally enables the new indexer. It is left until this
point in the series to avoid any regressions; in particular, it has to
come after the changes to the DWARF index writer to avoid this
problem.
However, if you experiment with the series, this patch can be moved
anywhere from the patch to wire in the new reader to this point.
Moving this patch around is how I got separate numbers for the
parallelization and background finalization patches.
In the ongoing performance example, this reduces the time from the
baseline of 1.598869 to 0.903534.
This updates the .gdb_index writer to work with the new DWARF scanner.
The .debug_names writer is deferred to another patch, to make review
simpler.
This introduces a small hack to psyms_seen_size, but is
inconsequential because this function will be deleted in a subsequent
patch.
This updates the DWARF index writing code to make the addrmap-writing
a bit more generic. Now, it can handle multiple maps, and it can work
using the maps generated by the new indexer.
Note that the new addrmap_index_data::using_index field will be
deleted in a future patch, when the rest of the DWARF psymtab code is
removed.
To support the removal of partial symtabs from the DWARF index writer,
this makes a small change to have write_address_map accept the address
map as a parameter, rather than assuming it always comes from the
per-BFD object.
In order to change the DWARF index writer to avoid partial symtabs,
this patch changes the key type in psym_index_map (and renames that
type as well). Using the dwarf2_per_cu_data as the key makes it
simpler to reuse this code with the new indexer.
After scanning the CUs, the DWARF indexer merges all the data into a
single vector, canonicalizing C++ names as it proceeds. While not
necessarily single-threaded, this process is currently done in just
one thread, to keep memory costs lower.
However, this work is all done without reference to any data outside
of the indexes. This patch improves the apparent performance of GDB
by moving it to the background. All uses of the index are then made
to wait for this process to complete.
In our ongoing example, this reduces the scanning time on gdb itself
to 0.173937 (wall). Recall that before this patch, the time was
0.668923; and psymbol reader does this in 1.598869. That is, at the
end of this series, we see about a 10x speedup.
This parallelizes the new DWARF indexer. The indexer's storage was
designed so that each storage object and each indexer is fully
independent. This setup makes it simple to scan different CUs
independently.
This patch creates a new cooked index storage object per thread, and
then scans a subset of all the CUs in each such thread, using gdb's
existing thread pool.
In the ongoing "gdb gdb" example, this patch reduces the wall time
down to 0.668923, from 0.903534. (Note that the 0.903534 is the time
for the new index -- that is, when the "enable the new index" patch is
rebased to before this one. However, in the final series, that patch
appears toward the end. Hopefully this isn't too confusing.)
Because BFD is not thread-safe, we need to be sure that any section
data that is needed is read before trying to do any DWARF indexing in
the background.
This patch takes a simple approach to this -- it pre-reads the
"info"-related sections. This is done for the main file, but also any
auxiliary files as well, such as the DWO file.
This patch could be perhaps enhanced by removing some now-redundant
calls to dwarf2_section_info::read.
This introduces a new class that can be used to make the "complaint"
code thread-safe. Instantiating the class installs a new handler that
collects complaints, and then prints them all when the object is
destroyed.
This approach requires some locks. I couldn't think of a better way
to handle this, though, because the I/O system is not thread-safe.
It seemed to me that only GDB developers are likely to enable
complaints, and because the complaint macro handle this case already
(before any locks are required), I reasoned that any performance
degradation that would result here would be fine.
As an aside about complaints -- are they useful at all? I just ignore
them, myself, since mostly they seem to indicate compiler problems
that can't be solved in the GDB world anyway. I'd personally prefer
them to be in a separate tool, like a hypothetical 'dwarflint'.
This wires the new DWARF indexer into the existing reader code. That
is, this patch makes the modification necessary to enable the new
indexer. It is not actually enabled by this patch -- that will be
done later.
I did a bit of performance testing for this patch and a few others. I
copied my built gdb to /tmp, so that each test would be done on the
same executable. Then, each time, I did:
$ ./gdb -nx
(gdb) maint time 1
(gdb) file /tmp/gdb
This patch is the baseline and on one machine came in at 1.598869 wall
time.
This implements quick_symbol_functions for the cooked DWARF index.
This is the code that interfaces between the new index and the rest of
gdb. Cooked indexes still aren't created by anything.
For the most part this is straightforward. It shares some concepts
with the existing DWARF indices. However, because names are stored
pre-split in the cooked index, name lookup here is necessarily
different; see expand_symtabs_matching for the gory details.
This patch adds the code to index DWARF. This is just the scanner; it
reads the DWARF and constructs the index, but nothing calls it yet.
The indexer is split into two parts: a storage object and an indexer
object. This is done to support the parallelization of this code -- a
future patch will create a single storage object per thread.
This patch introduces the new DWARF index class. It is called
"cooked" to contrast against a "raw" index, which is mapped from disk
without extra effort.
Nothing constructs a cooked index yet. The essential idea here is
that index entries are created via the "add" method; then when all the
entries have been read, they are "finalize"d -- name canonicalization
is performed and the entries are added to a sorted vector.
Entries use the DWARF name (DW_AT_name) or linkage name, not the full
name as is done for partial symbols.
These two facets -- the short name and the deferred canonicalization
-- help improve the performance of this approach. This will become
clear in later patches, when parallelization is added.
Some special code is needed for Ada, because GNAT only emits mangled
("encoded", in the Ada lingo) names, and so we reconstruct the
hierarchical structure after the fact. This is also done in the
finalization phase.
One other aspect worth noting is that the way the "main" function is
found is different in the new code. Currently gdb will notice
DW_AT_main_subprogram, but won't recognize "main" during reading --
this is done later, via explicit symbol lookup. This is done
differently in the new code so that finalization can be done in the
background without then requiring a synchronization to look up the
symbol.
The new DIE scanner works more or less along the lines indicated by
the text for the .debug_names section, disregarding the bugs in the
specification.
While working on this, I noticed that whether a DIE is interesting is
a static property of the DIE's abbrev. It also turns out that many
abbrevs imply a static size for the DIE data, and additionally that
for many abbrevs, the sibling offset is stored at a constant offset
from the start of the DIE.
This patch changes the abbrev reader to analyze each abbrev and stash
the results on the abbrev. These combine to speed up the new indexer.
If the "interesting" flag is false, GDB knows to skip the DIE
immediately. If the sibling offset is statically known, skipping can
be done without reading any attributes; and in some other cases, the
DIE can be skipped using simple arithmetic.
The replacement for the DWARF psymbol reader works in a somewhat
different way. The current reader reads and stores all the DIEs that
might be interesting. Then, if it is missing a DIE, it re-scans the
CU and reads them all. This approach is used for both intra- and
inter-CU references.
I instrumented the partial DIE hash to see how frequently it was used:
[ 0] -> 1538165
[ 1] -> 4912
[ 2] -> 96102
[ 3] -> 175
[ 4] -> 244
That is, most DIEs are never used, and some are looked up twice -- but
this is just an artifact of the implementation of
partial_die_info::fixup, which may do two lookups.
Based on this, the new implementation doesn't try to store any DIEs,
but instead just re-scans them on demand. In order to do this,
though, it is convenient to have a cache of DWARF abbrevs. This way,
if a second CU is needed to resolve an inter-CU reference, the abbrevs
for that CU need only be computed a single time.
This changes the file_and_directory object to be able to compute and
cache the "fullname" in the same way that is done by other code, like
the psymtab reader.
This adds a std::hash specialization for gdb_exception. This lets us
store these objects in a hash table, which is used later in this
series to de-duplicate the exception output from multiple threads.
