Tom Tromey [Sun, 18 Apr 2021 20:08:54 +0000 (14:08 -0600)]
Enable the new DWARF indexer
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.
Tom Tromey [Fri, 28 May 2021 21:52:44 +0000 (15:52 -0600)]
Genericize addrmap handling in the DWARF index writer
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.
Tom Tromey [Thu, 27 May 2021 22:29:52 +0000 (16:29 -0600)]
Change parameters to write_address_map
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.
Tom Tromey [Thu, 27 May 2021 20:59:32 +0000 (14:59 -0600)]
Change the key type in psym_index_map
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.
Tom Tromey [Sat, 22 May 2021 21:20:06 +0000 (15:20 -0600)]
"Finalize" the DWARF index in the background
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.
Tom Tromey [Sun, 18 Apr 2021 21:20:43 +0000 (15:20 -0600)]
Parallelize DWARF indexing
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.)
Tom Tromey [Mon, 28 Jun 2021 00:44:29 +0000 (18:44 -0600)]
Pre-read DWARF section data
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.
Tom Tromey [Mon, 6 Sep 2021 16:20:02 +0000 (10:20 -0600)]
Introduce thread-safe handling for complaints
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'.
Tom Tromey [Sat, 22 May 2021 13:54:06 +0000 (07:54 -0600)]
Wire in the new DWARF indexer
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.
Tom Tromey [Sat, 22 May 2021 13:53:40 +0000 (07:53 -0600)]
Implement quick_symbol_functions for cooked DWARF index
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.
Tom Tromey [Sat, 22 May 2021 13:51:24 +0000 (07:51 -0600)]
The new DWARF indexer
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.
Tom Tromey [Sun, 14 Mar 2021 17:38:54 +0000 (11:38 -0600)]
Introduce the new DWARF index class
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.
Tom Tromey [Sun, 7 Mar 2021 02:47:38 +0000 (19:47 -0700)]
Statically examine abbrev properties
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.
Tom Tromey [Tue, 3 Nov 2020 00:35:51 +0000 (17:35 -0700)]
Introduce DWARF abbrev cache
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:
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.
Tom Tromey [Tue, 30 Nov 2021 00:56:56 +0000 (17:56 -0700)]
Add "fullname" handling to file_and_directory
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.
Tom Tromey [Mon, 6 Sep 2021 21:22:44 +0000 (15:22 -0600)]
Specialize std::hash for gdb_exception
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.
Tom Tromey [Sun, 13 Jun 2021 18:46:28 +0000 (12:46 -0600)]
Return vector of results from parallel_for_each
This changes gdb::parallel_for_each to return a vector of the results.
However, if the passed-in function returns void, the return type
remains 'void'. This functionality is used later, to parallelize the
new indexer.
Tom Tromey [Sun, 23 May 2021 15:04:27 +0000 (09:04 -0600)]
Add batching parameter to parallel_for_each
parallel_for_each currently requires each thread to process at least
10 elements. However, when indexing, it's fine for a thread to handle
just a single CU. This patch parameterizes this, and updates the one
user.
Tom Tromey [Fri, 18 Jun 2021 21:36:40 +0000 (15:36 -0600)]
Refactor build_type_psymtabs_reader
The new DWARF scanner needs to save the entire cutu_reader object, not
just parts of it. In order to make this possible, this patch
refactors build_type_psymtabs_reader. This change is done separately
because it is easy to review in isolation and it helps make the later
patches smaller.
Tom Tromey [Sun, 21 Mar 2021 17:07:28 +0000 (11:07 -0600)]
Add name splitting
The new DWARF index code works by keeping names pre-split. That is,
rather than storing a symbol name like "a::b::c", the names "a", "b",
and "c" will be stored separately.
This patch introduces some helper code to split a full name into its
components.
Tom Tromey [Sat, 5 Jun 2021 15:24:52 +0000 (09:24 -0600)]
Allow ada_decode not to decode operators
The new DWARF scanner records names as they appear in DWARF. However,
because Ada is unusual, it also decodes the Ada names to synthesize
package components for them. In order for this to work out properly,
gdb also needs a mode where ada_decode can be instructed not to decode
Ada operator names. That is what this patch implements.
Tom Tromey [Sat, 12 Jun 2021 15:01:50 +0000 (09:01 -0600)]
Refactor dwarf2_get_pc_bounds
This changes dwarf2_get_pc_bounds so that it does not directly access
a psymtab or psymtabs_addrmap. Instead, both the addrmap and the
desired payload are passed as parameters. This makes it suitable to
be used by the new indexer.
Tom Tromey [Fri, 11 Jun 2021 19:23:28 +0000 (13:23 -0600)]
Add dwarf2_per_cu_data::addresses_seen
This adds a new member to dwarf2_per_cu_data that indicates whether
addresses have been seen for this CU. This is then set by the
.debug_aranges reader. The idea here is to detect when a CU does not
have address information, so that the new indexer will know to do
extra scanning in that case.
Tom Tromey [Tue, 16 Nov 2021 21:25:08 +0000 (14:25 -0700)]
Fix latent bug in read_addrmap_from_aranges
Tom de Vries found a failure that we tracked down to a latent bug in
read_addrmap_from_aranges (previously create_addrmap_from_aranges).
The bug is that this code can erroneously reject .debug_aranges when
dwz is in use, due to CUs at duplicate offsets. Because aranges can't
refer to a CU coming from the dwz file, the fix is to simply skip such
CUs in the loop.
Tom Tromey [Thu, 31 Mar 2022 02:19:54 +0000 (20:19 -0600)]
Allow thread-pool.h to work without threads
thread-pool.h requires CXX_STD_THREAD in order to even be included.
However, there's no deep reason for this, and during review we found
that one patch in the new DWARF indexer series unconditionally
requires the thread pool.
Because the thread pool already allows a task to be run in the calling
thread (for example if it is configured to have no threads in the
pool), it seemed straightforward to make this code ok to use when host
threads aren't available at all.
This patch implements this idea. I built it on a thread-less host
(mingw, before my recent configure patch) and verified that the result
builds.
After the thread-pool change, parallel-for.h no longer needs any
CXX_STD_THREAD checks at all, so this patch removes these as well.
Tom de Vries [Tue, 12 Apr 2022 14:36:31 +0000 (16:36 +0200)]
[gdb/testsuite] Fix gdb.base/stap-probe.exp with read1
When running test-case gdb.base/stap-probe.exp with make target check-read1, I
run into this and similar:
...
FAIL: gdb.base/stap-probe.exp: without semaphore, not optimized: \
info probes stap (timeout)
...
Fix this by using gdb_test_lines instead of gdb_test.
Tom Tromey [Tue, 12 Apr 2022 13:55:40 +0000 (07:55 -0600)]
Add C++ "save gdb-index" test
I found a bug in the new DWARF reader series, related to the handling
of enumerator names. This bug caused a crash, so this patch adds a
regression test for this particular case. I'm checking this in.
However, it turns out I somehow neglected to send part of the patch.
Internally, I also removed the "Ada Settings" node from the manual, as
it only documents the obsolete setting.
Tom Tromey [Thu, 17 Mar 2022 14:36:01 +0000 (08:36 -0600)]
Require GNAT debug info for some Ada tests
A few Ada tests require some debug info in the GNAT runtime. When run
without this info, these tests can't pass. This patch changes these
tests to detect this situation and stop with "untested".
Jan Beulich [Tue, 12 Apr 2022 07:04:42 +0000 (09:04 +0200)]
gas: new_logical_line{,_flags}() can return "void"
With the sole user of the return value gone, convert the return type to
void. This in turn allows simplifying another construct, by moving it
slightly later in the function.
Jan Beulich [Tue, 12 Apr 2022 07:04:15 +0000 (09:04 +0200)]
gas: drop .appfile and .appline
These were used originally to represent "# <line> <file>" constructs
inserted by (typically) compilers when pre-processing. Quite some time
ago they were replaced by .linefile though. Since the original
directives were never documented, we ought to be able to remove support
for them. As a result in a number of case function parameter aren't used
anymore and can hence be dropped.
Jan Beulich [Tue, 12 Apr 2022 07:03:43 +0000 (09:03 +0200)]
gas: further adjust file/line handling for .macro
Commit 7992631e8c0b ("gas/Dwarf: improve debug info generation from .irp
and alike blocks"), while dealing okay with actual assembly source files
not using .file/.line and alike outside but not inside of .macro, has
undue effects when the logical file/line pair was already overridden:
Line numbers would continuously increment while processing the expanded
macro, while the goal of the PR gas/16908 workaround is to keep the
expansion associated with the line invoking the macro. However, as soon
as enough state was overridden _inside_ the macro to cause as_where() to
no longer fall back top as_where_physical(), honor this by resuming the
bumping of the logical line number.
Note that from_sb_is_expansion's initializer was 1 for an unknown
reason. While renaming the variable and changing its type, also change
the initializer to "expanding_none", which would have been "0" in the
original code. Originally the initializer value itself wasn't ever used
anyway (requiring sb_index != -1), as it necessarily had changed in
input_scrub_include_sb() alongside setting sb_index to other than -1.
Strictly speaking input_scrub_insert_line() perhaps shouldn't use
expanding_none, yet none of the other enumerators fit there either. And
then strictly speaking that function probably shouldn't exist in the
first place. It's used only by tic54x.
Jan Beulich [Tue, 12 Apr 2022 07:03:13 +0000 (09:03 +0200)]
gas: further adjust file/line handling for .irp and alike
Commit 7992631e8c0b ("gas/Dwarf: improve debug info generation from .irp
and alike blocks"), while dealing okay with actual assembly source files
not using .file/.line and alike outside but not inside of .irp et al,
has undue effects when the logical file/line pair was already
overridden: Line numbers would continuously increment upon every
iteration, thus potentially getting far off. Furthermore it left it to
the user to actually insert .file/.line inside such constructs. Note
though that before aforementioned change things weren't pretty either:
Diagnostics (and debug info) would be associated with the directive
terminating the iteration construct, rather than with the actual lines.
Handle this automatically by simply latching the present line and then
re-instating coordinates first thing on every iteration; note that the
file can't change from what was previously pushed on the scrubber's
state stack, and hence can be taken from there by using a new flavor of
.linefile (which is far better memory-footprint-wise than recording the
full path in the inserted directive). (This then leaves undisturbed any
file/line control occurring in the body of the construct, as these will
only be seen and processed afterwards.)
gdb/doc: add section about Fortran intrinsic functions and types
The earlier version of this document had no sections about the
available Fortran intrinsic functions or the Fortran builtin types.
I added two sections 'Fortran intrinsics' and 'Fortran types' to
document the available Fortran language features. The subsection
'Fortran Defaults' has been integrated into the Fortran subsection.
gdb/fortran: rewrite intrinsic handling and add some missing overloads
The operators FLOOR, CEILING, CMPLX, LBOUND, UBOUND, and SIZE accept
(some only with Fortran 2003) the optional parameter KIND. This
parameter determines the kind of the associated return value. So far,
implementation of this kind parameter has been missing in GDB.
Additionally, the one argument overload for the CMPLX intrinsic function
was not yet available.
This patch adds overloads for all above mentioned functions to the
Fortran intrinsics handling in GDB.
It re-writes the intrinsic function handling section to use the helper
methods wrap_unop_intrinsic/wrap_binop_intrinsic/wrap_triop_intrinsic.
These methods define the action taken when a Fortran intrinsic function
is called with a certain amount of arguments (1/2/3). The helper methods
fortran_wrap2_kind and fortran_wrap3_kind have been added as equivalents
to the existing wrap and wrap2 methods.
After adding more overloads to the intrinsics handling, some of the
operation names were no longer accurate. E.g. UNOP_FORTRAN_CEILING
has been renamed to FORTRAN_CEILING as it is no longer a purely unary
intrinsic function. This patch also introduces intrinsic functions with
one, two, or three arguments to the Fortran parser and the
UNOP_OR_BINOP_OR_TERNOP_INTRINSIC token has been added.
gdb/fortran: Change GDB print for fortran default types
Currently, when asking GDB to print the type of a Fortran default type
such as INTEGER or REAL, GDB will return the default name of that type,
e.g. "integer"/"real":
(gdb) ptype integer
type = integer
(gdb) ptype real
type = real
For LOGICAL and COMPLEX it would return the actual underlying types
(gdb) ptype logical
type = logical*4
(gdb) ptype complex
type = complex*4
Similarly, GDB would print the default integer type for the underlying
default type:
(gdb) ptype integer*4
type = integer
(gdb) ptype real*4
type = real
(gdb) ptype logical
type = logical*4
(gdb) ptype complex*4
type = complex*4
This is inconsistent and a bit confusing. Both options somehow indicate
what the internal underlying type for the default type is - but I think
the logical/complex version is a bit clearer.
Consider again:
(gdb) ptype integer
type = integer
This indicates to a user that the type of "integer" is Fortran's default
integer type. Without examining "ptype integer*4" I would expect, that
any variable declared integer in the actual code would also fit into a
GDB integer. But, since we cannot adapt out internal types to the
compiler flags used at compile time of a debugged binary, this might be
wrong. Consider debugging Fortran code compiled with GNU and e.g. the
"-fdefault-integer-8" flag. In this case the gfortran default integer
would be integer*8 while GDB internally still would use a builtin_integer,
so an integer of the size of an integer*4 type. On the other hand having
GDB print
(gdb) ptype integer
type = integer*4
makes this clearer. I would still be tempted to fit a variable declared
integer in the code into a GDB integer - but at least ptype would
directly tell me what is going on. Note, that when debugging a binary
compiled with "-fdefault-integer-8" a user will always see the actual
underlying type of any variable declared "integer" in the Fortran code.
So having the code
program test
integer :: a = 5
print *, a ! breakpt
end program test
will, when breaking at breakpt print
(gdb) ptype var
type = integer(kind=4)
or
(gdb) ptype var
type = integer(kind=8)
depending on the compiler flag.
This patch changes the outputs for the REAL and INTEGER default types to
actually print the internally used type over the default type name.
The new behavior for the above examples is:
(gdb) ptype integer
type = integer*4
(gdb) ptype integer*4
type = integer*4
Existing testcases have been adapted to reflect the new behavior.
The currently implemented intrinsic type handling for Fortran missed some
tokens and their parsing. While still not all Fortran type kinds are
implemented this patch at least makes the currently handled types
consistent. As an example for what this patch does, consider the
intrinsic type INTEGER. GDB implemented the handling of the
keywords "integer" and "integer_2" but missed "integer_4" and "integer_8"
even though their corresponding internal types were already available as
the Fortran builtin types builtin_integer and builtin_integer_s8.
Similar problems applied to LOGICAL, REAL, and COMPLEX. This patch adds
all missing tokens and their parsing. Whenever a section containing the
type handling was touched, it also was reordered to be in a more easy to
grasp order. All INTEGER/REAL/LOGICAL/COMPLEX types were grouped
together and ordered ascending in their size making a missing one more
easy to spot.
Before this change GDB would print the following when tyring to use the
INTEGER keywords:
(gdb) set language fortran
(gdb) ptype integer*1
unsupported kind 1 for type integer
(gdb) ptype integer_1
No symbol table is loaded. Use the "file" command.
(gdb) ptype integer*2
type = integer*2
(gdb) ptype integer_2
type = integer*2
(gdb) ptype integer*4
type = integer
(gdb) ptype integer_4
No symbol table is loaded. Use the "file" command.
(gdb) ptype integer*8
type = integer*8
(gdb) ptype integer_8
No symbol table is loaded. Use the "file" command.
(gdb) ptype integer
type = integer
With this patch all keywords are available and the GDB prints:
(gdb) set language fortran
(gdb) ptype integer*1
type = integer*1
(gdb) ptype integer_1
type = integer*1
(gdb) ptype integer*2
type = integer*2
(gdb) ptype integer_2
type = integer*2
(gdb) ptype integer*4
type = integer*4
(gdb) ptype integer_4
type = integer*4
(gdb) ptype integer*8
type = integer*8
(gdb) ptype integer_8
type = integer*8
(gdb) ptype integer
type = integer
The described changes have been applied to INTEGER, REAL, COMPLEX,
and LOGICAL. Existing testcases have been adapted to reflect the
new behavior. Tests for formerly missing types have been added.
gdb/fortran: change default logical type to builtin_logical
According to the Fortran standard, logical is of the size of a
'single numeric storage unit' (just like real and integer). For
gfortran, flang and ifx/ifort this storage unit (or the default
logical type) is of size kind 4, actually occupying 4 bytes of
storage, and so the default type for logical expressions in
Fortran should probably also be Logical*4 and not Logical*2. I
adapted GDB's behavior to be in line with
gfortran/ifort/ifx/flang.
were possible in GDB, which seems confusing for a user. The reason
is a mixup in the implementation of the Fortran COMPLEX type. In
Fortran the "*X" after a type would normally (I don't think this
is language required) specify the type's size in memory. For the
COMPLEX type the kind parameters usually (at least for GNU, Intel, Flang)
specify not the size of the whole type but the size of the individual
two REALs used to form the COMPLEX. Thus, a COMPLEX*4 will usually
consist of two REAL*4s. Internally this type was represented by a
builtin_complex_s8 - but here I think the s8 actually meant the raw
size of the type. This is confusing and I renamed the types (e.g.
builting_complex_s8 became builtin_complex_s4 according to its most
common useage) and their printed names to their language equivalent.
Additionally, I added the default COMPLEX type "COMPLEX" being the same
as a COMPLEX*4 (as is normally the case) and removed the latter. I added
a few tests for this new behavior as well.
Tom de Vries [Mon, 11 Apr 2022 08:28:41 +0000 (10:28 +0200)]
[gdb/testsuite] Fix gdb.base/annota1.exp with pie
Since commit 359efc2d894 ("[gdb/testsuite] Make gdb.base/annota1.exp more
robust") we see this fail with target board unix/-fPIE/-pie:
...
FAIL: gdb.base/annota1.exp: run until main breakpoint (timeout)
...
The problem is that the commit makes the number and order of matched
annotations fixed, while between target boards unix and unix/-fPIE/-pie there
is a difference:
...
\032\032post-prompt
Starting program: outputs/gdb.base/annota1/annota1
+\032\032breakpoints-invalid
+
\032\032starting
\032\032frames-invalid
...
Fix this by optionally matching the additional annotation.
Tom de Vries [Mon, 11 Apr 2022 08:17:31 +0000 (10:17 +0200)]
[gdb/testsuite] Fix gdb.dwarf2/dw2-lines.exp for m32 pie
As reported in PR29043, when running test-case gdb.dwarf2/dw2-lines.exp with
target board unix/-m32/-fPIE/-pie, we run into:
...
Breakpoint 2, 0x56555540 in bar ()^M
(gdb) PASS: gdb.dwarf2/dw2-lines.exp: cv=2: cdw=32: lv=2: ldw=32: \
continue to breakpoint: foo \(1\)
next^M
Single stepping until exit from function bar,^M
which has no line number information.^M
0x56555587 in main ()^M
(gdb) FAIL: gdb.dwarf2/dw2-lines.exp: cv=2: cdw=32: lv=2: ldw=32: \
next to foo (2)
...
The problem is that the bar breakpoint ends up at an unexpected location
because:
- the synthetic debug info is incomplete and doesn't provide line info
for the prologue part of the function, so consequently gdb uses the i386
port prologue skipper to get past the prologue
- the i386 port prologue skipper doesn't get past a get_pc_thunk call.
Work around this in the test-case by breaking on bar_label instead.
Tested on x86_64-linux with target boards unix, unix/-m32, unix/-fPIE/-pie and
unix/-m32/-fPIE/-pie.
Alan Modra [Mon, 4 Apr 2022 12:04:06 +0000 (21:34 +0930)]
Rearrange struct bfd_section a little
For better packing on 64-bit hosts.
* section.c (struct bfd_section): Move next and prev field earlier.
Move alignment_power later.
(BFD_FAKE_SECTION): Adjust to suit.
* bfd-in2.h: Regenerate.
Alan Modra [Sat, 9 Apr 2022 05:56:25 +0000 (15:26 +0930)]
Don't run pr27228 test for hppa
As the comment says, hppa doesn't support use of BFD_RELOC_* in
.reloc directives. Using xfail can result in a spurious XPASS result
as BFD_RELOC values change.
* testsuite/gas/elf/pr27228.d: Change xfail to notarget for hppa.
Pedro Alves [Fri, 1 Apr 2022 12:26:57 +0000 (13:26 +0100)]
gdb: Avoid undefined shifts, fix Go shifts
I noticed that a build of GDB with GCC + --enable-ubsan, testing
against GDBserver showed this GDB crash:
(gdb) PASS: gdb.trace/trace-condition.exp: trace: 0x00abababcdcdcdcd << 46 == 0x7373400000000000: advance to trace begin
tstart
../../src/gdb/valarith.c:1365:15: runtime error: left shift of 48320975398096333 by 46 places cannot be represented in type 'long int'
ERROR: GDB process no longer exists
GDB process exited with wait status 269549 exp9 0 1
UNRESOLVED: gdb.trace/trace-condition.exp: trace: 0x00abababcdcdcdcd << 46 == 0x7373400000000000: start trace experiment
The problem is that, "0x00abababcdcdcdcd << 46" is an undefined signed
left shift, because the result is not representable in the type of the
lhs, which is signed. This actually became defined in C++20, and if
you compile with "g++ -std=c++20 -Wall", you'll see that GCC no longer
warns about it, while it warns if you specify prior language versions.
While at it, there are a couple other situations that are undefined
(and are still undefined in C++20) and result in GDB dying: shifting
by a negative ammount, or by >= than the bit size of the promoted lhs.
For the latter, GDB shifts using (U)LONGEST internally, so you have to
shift by >= 64 bits to see it:
$ gdb --batch -q -ex "p 1 << 64"
../../src/gdb/valarith.c:1365:15: runtime error: shift exponent 64 is too large for 64-bit type 'long int'
$ # gdb exited
Also, right shifting a negative value is implementation-defined
(before C++20, after which it is defined). For this, I chose to
change nothing in GDB other than adding tests, as I don't really know
whether we need to do anything. AFAIK, most implementations do an
arithmetic right shift, and it may be we don't support any host or
target that behaves differently. Plus, this becomes defined in C++20
exactly as arithmetic right shift.
Compilers don't error out on such shifts, at best they warn, so I
think GDB should just continue doing the shifts anyhow too.
Thus:
- Adjust scalar_binop to avoid the undefined paths, either by adding
explicit result paths, or by casting the lhs of the left shift to
unsigned, as appropriate.
For the shifts by a too-large count, I made the result be what you'd
get if you split the large count in a series of smaller shifts.
Thus:
Left shift, positive or negative lhs:
V << 64
=> V << 16 << 16 << 16 << 16
=> 0
Right shift, positive lhs:
Vpos >> 64
=> Vpos >> 16 >> 16 >> 16 >> 16
=> 0
Right shift, negative lhs:
Vneg >> 64
=> Vneg >> 16 >> 16 >> 16 >> 16
=> -1
This is actually Go's semantics (the compiler really emits
instructions to make it so that you get 0 or -1 if you have a
too-large shift). So for that language GDB does the shift and
nothing else. For other C-like languages where such a shift is
undefined, GDB warns in addition to performing the shift.
For shift by a negative count, for Go, this is a hard error. For
other languages, since their compilers only warn, I made GDB warn
too. The semantics I chose (we're free to pick them since this is
undefined behavior) is as-if you had shifted by the count cast to
unsigned, thus as if you had shifted by a too-large count, thus the
same as the previous scenario illustrated above.
Examples:
(gdb) set language go
(gdb) p 1 << 100
$1 = 0
(gdb) p -1 << 100
$2 = 0
(gdb) p 1 >> 100
$3 = 0
(gdb) p -1 >> 100
$4 = -1
(gdb) p -2 >> 100
$5 = -1
(gdb) p 1 << -1
left shift count is negative
(gdb) set language c
(gdb) p -2 >> 100
warning: right shift count >= width of type
$6 = -1
(gdb) p -2 << 100
warning: left shift count >= width of type
$7 = 0
(gdb) p 1 << -1
warning: left shift count is negative
$8 = 0
(gdb) p -1 >> -1
warning: right shift count is negative
$9 = -1
- The warnings' texts are the same as what GCC prints.
- Add comprehensive tests in a new gdb.base/bitshift.exp testcase, so
that we exercise all these scenarios.
... to the Fortran, Go, and Fortran number parsers, fixing the same
problems there.
Also add a new testcase that exercises printing 0xffffffffffffffff
(max 64-bit) in all languages, which crashes a GDB built with UBsan
without the fix.
I moved get_set_option_choices out of all-architectures.exp.tcl to
common code to be able to extract all the supported languages. I did
a tweak to it to generalize it a bit -- you now have to pass down the
"set" part of the command as well. This is so that the proc can be
used with "maintenance set" commands as well in future.
Simon Marchi [Fri, 8 Apr 2022 14:56:41 +0000 (10:56 -0400)]
Pass PKG_CONFIG_PATH down from top-level Makefile
[Sending to binutils, gdb-patches and gcc-patches, since it touches the
top-level Makefile/configure]
I have my debuginfod library installed in a non-standard location
(/opt/debuginfod), which requires me to set
PKG_CONFIG_PATH=/opt/debuginfod/lib/pkg-config. If I just set it during
configure:
$ PKG_CONFIG_PATH=/opt/debuginfod/lib/pkg-config ./configure --with-debuginfod
$ make
or
$ ./configure --with-debuginfod PKG_CONFIG_PATH=/opt/debuginfod/lib/pkg-config
$ make
Then PKG_CONFIG_PATH is only present (and ignored) during the top-level
configure. When running make (which runs gdb's and binutils'
configure), PKG_CONFIG_PATH is not set, which results in their configure
script not finding the library:
checking for libdebuginfod >= 0.179... no
configure: error: "--with-debuginfod was given, but libdebuginfod is missing or unusable."
Change the top-level configure/Makefile system to capture the value
passed when configuring the top-level and pass it down to
subdirectories (similar to CFLAGS, LDFLAGS, etc).
I don't know much about the top-level build system, so I really don't
know if I did this correctly. The changes are:
- Use AC_SUBST(PKG_CONFIG_PATH) in configure.ac, so that
@PKG_CONFIG_PATH@ gets replaced with the actual PKG_CONFIG_PATH value
in config files (i.e. Makefile)
- Add a PKG_CONFIG_PATH Makefile variable in Makefile.tpl, initialized
to @PKG_CONFIG_PATH@
- Add PKG_CONFIG_PATH to HOST_EXPORTS in Makefile.tpl, which are the
variables set when running the sub-configures
I initially added PKG_CONFIG_PATH to flags_to_pass, in Makefile.def, but
I don't think it's needed. AFAIU, this defines the flags to pass down
when calling "make" in subdirectories. We only need PKG_CONFIG_PATH to
be passed down during configure. After that, it's captured in
gdb/config.status, so even if a "make" causes a re-configure later
(because gdb/configure has changed, for example), the PKG_CONFIG_PATH
value will be remembered.
Simon Marchi [Thu, 7 Apr 2022 19:08:57 +0000 (15:08 -0400)]
gdb/testsuite: use nopie in gdb.dwarf2/dw2-inline-param.exp
I see this failure:
(gdb) run ^M
Starting program: /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.dwarf2/dw2-inline-param/dw2-inline-param ^M
Warning:^M
Cannot insert breakpoint 1.^M
Cannot access memory at address 0x113b^M
^M
(gdb) FAIL: gdb.dwarf2/dw2-inline-param.exp: runto: run to *0x113b
The test loads the binary in GDB, grabs the address of a symbol, strips
the binary, reloads it in GDB, runs the program, and then tries to place
a breakpoint at that address. The problem is that the binary is built
as position independent, so the address GDB grabs in the first place
isn't where the code ends up after running.
Fix this by linking the binary as non-position-independent. The
alternative would be to compute the relocated address where to place the
breakpoint, but that's not very straightforward, unfortunately.
I was confused for a while, I was trying to load the binary in GDB
manually to get the symbol address, but GDB was telling me the symbol
could not be found. Meanwhile, it clearly worked in gdb.log. The thing
is that GDB strips the binary in-place, so we don't have access to the
intermediary binary with symbols. Change the test to output the
stripped binary to a separate file instead.
Bernhard Heckel [Tue, 5 Apr 2022 15:44:46 +0000 (17:44 +0200)]
gdb/fortran: print fortran extended types with ptype
Add the print of the base-class of an extended type to the output of
ptype. This requires the Fortran compiler to emit DW_AT_inheritance
for the extended type.
Bernhard Heckel [Tue, 5 Apr 2022 15:44:46 +0000 (17:44 +0200)]
gdb/fortran: add support for accessing fields of extended types
Fortran 2003 supports type extension. This patch allows access
to inherited members by using their fully qualified name as described
in the Fortran standard.
In doing so the patch also fixes a bug in GDB when trying to access the
members of a base class in a derived class via the derived class' base
class member.
This patch fixes PR22497 and PR26373 on GDB side.
Using the example Fortran program from PR22497
program mvce
implicit none
type :: my_type
integer :: my_int
end type my_type
type, extends(my_type) :: extended_type
end type extended_type
type(my_type) :: foo
type(extended_type) :: bar
foo%my_int = 0
bar%my_int = 1
print*, foo, bar
end program mvce
and running this with GDB and setting a BP at 17:
Before:
(gdb) p bar%my_type
A syntax error in expression, near `my_type'.
(gdb) p bar%my_int
There is no member named my_int.
(gdb) p bar%my_type%my_int
A syntax error in expression, near `my_type%my_int'.
(gdb) p bar
$1 = ( my_type = ( my_int = 1 ) )
After:
(gdb) p bar%my_type
$1 = ( my_int = 1 )
(gdb) p bar%my_int
$2 = 1 # this line requires DW_TAG_inheritance to work
(gdb) p bar%my_type%my_int
$3 = 1
(gdb) p bar
$4 = ( my_type = ( my_int = 1 ) )
In the above example "p bar%my_int" requires the compiler to emit
information about the inheritance relationship between extended_type
and my_type which gfortran and flang currently do not de. The
respective issue gcc/49475 has been put as kfail.
gdb: add support for Fortran's ASSUMED RANK arrays
Added support for Fortran assumed rank arrays. Unfortunately, this
commit contained a bug that means though GDB can correctly calculate
the rank of an assumed rank array, GDB can't fetch the contents of an
assumed rank array.
The history of this patch can be seen on the mailing list here:
The original patches did support fetching the array contents, it was
only the later series that introduced the regression.
The problem is that when calculating the array rank the result is a
count of the number of ranks, i.e. this is a 1 based result, 1, 2, 3,
etc.
In contrast, when computing the details of any particular rank the
value passed to the DWARF expression evaluator should be a 0 based
rank offset, i.e. a 0 based number, 0, 1, 2, etc.
In the patches that were originally merged, this was not the case, and
we were passing the 1 based rank number to the expression evaluator,
e.g. passing 1 when we should pass 0, 2 when we should pass 1, etc.
As a result the DWARF expression evaluator was reading the
wrong (undefined) memory, and returning garbage results.
In this commit I have extended the test case to cover checking the
array contents, I've then ensured we make use of the correct rank
value, and extended some comments, and added or adjusted some asserts
as appropriate.
Simon Marchi [Thu, 7 Apr 2022 01:51:57 +0000 (21:51 -0400)]
gdb/testsuite: add "macros" option to gdb_compile
Make gdb_compile handle a new "macros" option, which makes it pass the
appropriate flag to make the compiler include macro information in the
debug info. This will help simplify tests using macros, reduce
redundant code, and make it easier to add support for a new compiler.
Right now it only handles clang specially (using -fdebug-macro) and
falls back to -g3 otherwise (which works for gcc). Other compilers can
be added as needed.
There are some tests that are currently skipped if the compiler is nor
gcc nor clang. After this patch, the tests will attempt to run (the -g3
fall back will be used). That gives a chance to people using other
compilers to notice something is wrong and maybe add support for their
compiler. If it is needed to support a compiler that doesn't have a way
to include macro information, then we can always introduce a
"skip_macro_tests" that can be used to skip over them.
Tom de Vries [Thu, 7 Apr 2022 17:25:26 +0000 (19:25 +0200)]
[gdb/testsuite] Make gdb.base/annota1.exp more robust
On openSUSE Tumbleweed I run into:
...
FAIL: gdb.base/annota1.exp: run until main breakpoint (timeout)
...
The problem is that the libthread_db message occurs at a location where it's
not expected:
...
Starting program: outputs/gdb.base/annota1/annota1 ^M
^M
^Z^Zstarting^M
^M
^Z^Zframes-invalid^M
[Thread debugging using libthread_db enabled]^M
Using host libthread_db library "/lib64/libthread_db.so.1".^M
^M
^Z^Zbreakpoints-invalid^M
^M
...
Fix this by making the matching more robust:
- rewrite the regexp such that each annotation is on a single line,
starting with \r\n\032\032 and ending with \r\n
- add a regexp variable optional_re, that matches all possible optional
output, and use it as a separator in the first part of the regexp
Simon Marchi [Thu, 7 Apr 2022 01:51:55 +0000 (21:51 -0400)]
gdb/testsuite/dwarf: simplify line number program syntax
By calling `uplevel $body` in the program proc (a pattern we use at many
places), we can get rid of curly braces around each line number program
directive. That seems like a nice small improvement to me.
Simon Marchi [Tue, 29 Mar 2022 20:14:36 +0000 (16:14 -0400)]
gdb: remove symtab::objfile
Same idea as previous patch, but for symtab::objfile. I find
it clearer without this wrapper, as it shows that the objfile is
common to all symtabs of a given compunit. Otherwise, you could think
that each symtab (of a given compunit) can have a specific objfile.
Simon Marchi [Wed, 6 Apr 2022 14:42:03 +0000 (10:42 -0400)]
gdb: remove symtab::blockvector
symtab::blockvector is a wrapper around compunit_symtab::blockvector.
It is a bit misleadnig, as it gives the impression that a symtab has a
blockvector. Remove it, change all users to fetch the blockvector
through the compunit instead.
Simon Marchi [Wed, 6 Apr 2022 14:42:02 +0000 (10:42 -0400)]
gdb: remove symtab::dirname
I think the symtab::dirname method is bogus, or at least very
misleading. It makes you think that it returns the directory that was
used to find that symtab's file during compilation (i.e. the directory
the file refers to in the DWARF line header file table), or the
directory part of the symtab's filename maybe. In fact, it returns the
compilation unit's directory, which is the CWD of the compiler, at
compilation time. At least for DWARF, if the symtab's filename is
relative, it will be relative to that directory. But if the symtab's
filename is absolute, then the directory returned by symtab::dirname has
nothing to do with the symtab's filename.
Remove symtab::dirname to avoid this confusion, change all users to
fetch the same information through the compunit. At least, it will be
clear that this is a compunit property, not a symtab property.
Simon Marchi [Tue, 8 Feb 2022 21:31:09 +0000 (16:31 -0500)]
gdb/testsuite: make gdb_breakpoint and runto take a linespec
Change gdb_breakpoint to accept a linespec, not just a function. In
fact, no behavior changes are necessary, this only changes the parameter
name and documentation. Change runto as well, since the two are so
close (runto forwards all its arguments to gdb_breakpoint).
I wrote this for a downstrean GDB port, but thought it could be
useful upstream, eventually, even though not callers take advantage of
it yet.
Andrew Burgess [Thu, 31 Mar 2022 17:19:23 +0000 (18:19 +0100)]
gdb: update comments throughout reggroups.{c,h} files
This commit updates the comments in the gdb/reggroups.{c,h} files.
Fill in some missing comments, correct a few comments that were not
clear, and where we had comments duplicated between .c and .h files,
update the .c to reference the .h.
Andrew Burgess [Thu, 31 Mar 2022 17:10:34 +0000 (18:10 +0100)]
gdb: move struct reggroup into reggroups.h header
Move 'struct reggroup' into the reggroups.h header. Remove the
reggroup_name and reggroup_type accessor functions, and just use the
name/type member functions within 'struct reggroup', update all uses
of these removed functions.
There should be no user visible changes after this commit.