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2025-04-29gdb/dwarf: scan .debug_info.dwo just onceSimon Marchi2-183/+94
When building -gsplit-dwarf and -fdebug-types-section in DWARF 5, the resulting .dwo files will typically have a .debug_info.dwo section with multiple type units followed by one compile unit: $ llvm-dwarfdump -F -color a-test.dwo | grep ' Unit' 0x00000000: Type Unit: length = 0x000008a0, format = DWARF32, version = 0x0005, unit_type = DW_UT_split_type, abbr_offset = 0x0000, addr_size = 0x08, name = 'vector<int, std::allocator<int> >', type_signature = 0xb499dcf29e2928c4, type_offset = 0x0023 (next unit at 0x000008a4) 0x000008a4: Type Unit: length = 0x00000099, format = DWARF32, version = 0x0005, unit_type = DW_UT_split_type, abbr_offset = 0x0000, addr_size = 0x08, name = 'allocator<int>', type_signature = 0x496a8791a842701b, type_offset = 0x0023 (next unit at 0x00000941) ... 0x000015c1: Compile Unit: length = 0x00000f58, format = DWARF32, version = 0x0005, unit_type = DW_UT_split_compile, abbr_offset = 0x0000, addr_size = 0x08, DWO_id = 0xe8e359820d1c5803 (next unit at 0x0000251d) In open_and_init_dwo_file, we call create_dwo_cus_hash_table, which scans the section, looking for compile units, then call create_dwo_debug_types_hash_table, which scans the section again, looking for type units. It would make more sense to scan the section just once and handle both compile and type units at the same time. To achieve this, add create_dwo_unit_hash_tables, which knows how to handle both unit kinds in a single scan. It replaces create_dwo_cus_hash_table and create_dwo_debug_type_hash_table. Change open_and_init_dwo_file to call it. Note that I removed the DWARF version check in open_and_init_dwo_file when processing .debug_type.dwo sections: in DWARF 5, the .debug_type.dwo sections will just not exist, so the `dwo_file->sections.types` vector will be empty. Change-Id: I6e51d0ca06c258e0bf0e59927d62ae2df314a162 Approved-By: Tom Tromey <tom@tromey.com>
2025-04-29gdb/dwarf: scan DWARF 5 DWO CUs by just reading the headerSimon Marchi1-24/+50
create_dwo_cus_hash_table is implemented by creating a cutu_reader (which is somewhat heavy) for all units in a .dwo file. The purpose of this cutu_reader is to be able to get the DWO ID, if it is specified by a DW_AT_GNU_dwo_id attribute. In DWARF 5, however, the DWO ID is available in the CU header. We can access it without accessing the DIEs, by just reading the header, which is more lightweight. Add a new code path to create_dwo_cus_hash_table that does that. The logic is copied from create_dwo_debug_type_hash_table, which does this already. This change helps circumvent a performance problem I want to fix (the same I was trying to fix in this patch [1]) when loading a file built with -gdwarf-5, -gsplit-dwarf and -fdebug-types-section. In this configuration, the produced .dwo files contain one compile unit and many type units each. All units in a given .dwo share the same abbrev table. Creating a cutu_reader for each unit meant re-reading the same abbrev table over and over. What's particularly bad is that this is done with the dwo_lock held, preventing other indexing threads from making progress. To give a rough idea, here's the time take by each worker to index units before this patch (on a rather large program): Time for "DWARF indexing worker": wall 18.627, user 0.885, sys 0.042, user+sys 0.927, 5.0 % CPU Time for "DWARF indexing worker": wall 18.888, user 0.862, sys 0.042, user+sys 0.904, 4.8 % CPU Time for "DWARF indexing worker": wall 19.172, user 1.848, sys 0.069, user+sys 1.917, 10.0 % CPU Time for "DWARF indexing worker": wall 19.297, user 1.544, sys 0.051, user+sys 1.595, 8.3 % CPU Time for "DWARF indexing worker": wall 19.545, user 3.408, sys 0.084, user+sys 3.492, 17.9 % CPU Time for "DWARF indexing worker": wall 19.759, user 4.221, sys 0.117, user+sys 4.338, 22.0 % CPU Time for "DWARF indexing worker": wall 19.789, user 4.187, sys 0.105, user+sys 4.292, 21.7 % CPU Time for "DWARF indexing worker": wall 19.825, user 4.933, sys 0.135, user+sys 5.068, 25.6 % CPU And the times with this patch: Time for "DWARF indexing worker": wall 0.163, user 0.089, sys 0.029, user+sys 0.118, 72.4 % CPU Time for "DWARF indexing worker": wall 0.176, user 0.096, sys 0.041, user+sys 0.137, 77.8 % CPU Time for "DWARF indexing worker": wall 0.265, user 0.167, sys 0.054, user+sys 0.221, 83.4 % CPU Time for "DWARF indexing worker": wall 0.353, user 0.257, sys 0.060, user+sys 0.317, 89.8 % CPU Time for "DWARF indexing worker": wall 0.524, user 0.399, sys 0.088, user+sys 0.487, 92.9 % CPU Time for "DWARF indexing worker": wall 0.648, user 0.517, sys 0.107, user+sys 0.624, 96.3 % CPU Time for "DWARF indexing worker": wall 0.657, user 0.523, sys 0.107, user+sys 0.630, 95.9 % CPU Time for "DWARF indexing worker": wall 0.753, user 0.612, sys 0.120, user+sys 0.732, 97.2 % CPU [1] https://inbox.sourceware.org/gdb-patches/20250326200002.136200-8-simon.marchi@efficios.com/ Change-Id: I34a422577e4c3ad7d478ec6df12a0e44d284c249 Approved-By: Tom Tromey <tom@tromey.com>
2025-04-29gdb/dwarf: replace some "compile unit" terminology with "unit"Simon Marchi10-177/+167
In DWARF 5 (and even previous versions, with type units), compile units are just one type of units. In many places, we still use "compile units" when in reality it would be better to talk about "units" (unless we specifically want to talk about compile units). Rename comp-unit-head.{c.h} to unit-head.{c,h}, and do a big pass of renames in it to remove the specific mentions of compile units, where in fact we want to talk about units in general. Change-Id: Ia06c90ccb25756c366f269a12620f2f7c8378adb Approved-By: Tom Tromey <tom@tromey.com>
2025-04-29gdb: add some scoped_time_its to profile startup timeSimon Marchi4-3/+20
I'm investigating some issues where GDB takes a lot of time to start up (read: for the DWARF index to be ready to do anything useful). Adding those scoped_time_it instances helped me gain some insights about where GDB spends time. I think they would be useful to have upstream, to make investigating future problems easier. It would also be useful to be able to give some numbers in the commit messages. Here's an example of what GDB outputs: Time for "minsyms install worker": wall 0.045, user 0.040, sys 0.004, user+sys 0.044, 97.8 % CPU Time for "minsyms install worker": wall 0.511, user 0.457, sys 0.048, user+sys 0.505, 98.8 % CPU Time for "minsyms install worker": wall 1.513, user 1.389, sys 0.111, user+sys 1.500, 99.1 % CPU Time for "minsyms install worker": wall 1.688, user 1.451, sys 0.102, user+sys 1.553, 92.0 % CPU Time for "minsyms install worker": wall 1.897, user 1.518, sys 0.089, user+sys 1.607, 84.7 % CPU Time for "minsyms install worker": wall 2.811, user 2.558, sys 0.231, user+sys 2.789, 99.2 % CPU Time for "minsyms install worker": wall 3.257, user 3.049, sys 0.188, user+sys 3.237, 99.4 % CPU Time for "minsyms install worker": wall 3.617, user 3.089, sys 0.211, user+sys 3.300, 91.2 % CPU Time for "DWARF indexing worker": wall 19.517, user 0.894, sys 0.075, user+sys 0.969, 5.0 % CPU Time for "DWARF indexing worker": wall 19.807, user 0.891, sys 0.086, user+sys 0.977, 4.9 % CPU Time for "DWARF indexing worker": wall 20.270, user 1.559, sys 0.119, user+sys 1.678, 8.3 % CPU Time for "DWARF indexing worker": wall 20.329, user 1.878, sys 0.147, user+sys 2.025, 10.0 % CPU Time for "DWARF indexing worker": wall 20.848, user 3.483, sys 0.224, user+sys 3.707, 17.8 % CPU Time for "DWARF indexing worker": wall 21.088, user 4.285, sys 0.295, user+sys 4.580, 21.7 % CPU Time for "DWARF indexing worker": wall 21.109, user 4.501, sys 0.274, user+sys 4.775, 22.6 % CPU Time for "DWARF indexing worker": wall 21.198, user 5.087, sys 0.319, user+sys 5.406, 25.5 % CPU Time for "DWARF skeletonless type units": wall 4.024, user 3.858, sys 0.115, user+sys 3.973, 98.7 % CPU Time for "DWARF add parent map": wall 0.092, user 0.086, sys 0.004, user+sys 0.090, 97.8 % CPU Time for "DWARF finalize worker": wall 0.278, user 0.241, sys 0.009, user+sys 0.250, 89.9 % CPU Time for "DWARF finalize worker": wall 0.307, user 0.304, sys 0.000, user+sys 0.304, 99.0 % CPU Time for "DWARF finalize worker": wall 0.727, user 0.719, sys 0.000, user+sys 0.719, 98.9 % CPU Time for "DWARF finalize worker": wall 0.913, user 0.901, sys 0.003, user+sys 0.904, 99.0 % CPU Time for "DWARF finalize worker": wall 0.776, user 0.767, sys 0.004, user+sys 0.771, 99.4 % CPU Time for "DWARF finalize worker": wall 1.897, user 1.869, sys 0.006, user+sys 1.875, 98.8 % CPU Time for "DWARF finalize worker": wall 2.534, user 2.512, sys 0.005, user+sys 2.517, 99.3 % CPU Time for "DWARF finalize worker": wall 2.607, user 2.583, sys 0.006, user+sys 2.589, 99.3 % CPU Time for "DWARF finalize worker": wall 3.142, user 3.094, sys 0.022, user+sys 3.116, 99.2 % CPU Change-Id: I9453589b9005c3226499428ae9cab9f4a8c22904 Approved-By: Tom Tromey <tom@tromey.com>
2025-04-29gdb: add scoped_time_itSimon Marchi3-1/+72
New in v2: - actually use m_enabled in the constructor and destructor - output using gdb_stdlog->write_async_safe instead of gdb_printf scoped_time_it is a small utility that measures and prints how much time a given thread spent in a given scope. Similar to the time(1) command, it prints the time spent in user mode, system mode, and the wall clock time. It also prints the CPU utilization percentage, which is: (user + sys) / wall This can help spot cases where the workload is not well balanced between workers, or the CPU utilization is not optimal (perhaps due to contention around a lock for example). To use it, just add it in some scope. For instance, a subsequent patch adds it here: workers.add_task ([this, task_count, iter, last] () { scoped_time_it time_it ("DWARF indexing worker"); process_cus (task_count, iter, last); }); On destruction, if enabled, it prints a line showing the time spent by that thread, similar to what time(1) prints. The example above prints this (one line for each worker thread): Time for "DWARF indexing worker": wall 0.173, user 0.120, sys 0.034, user+sys 0.154, 89.0 % CPU Time for "DWARF indexing worker": wall 0.211, user 0.144, sys 0.047, user+sys 0.191, 90.5 % CPU Time for "DWARF indexing worker": wall 0.368, user 0.295, sys 0.057, user+sys 0.352, 95.7 % CPU Time for "DWARF indexing worker": wall 0.445, user 0.361, sys 0.072, user+sys 0.433, 97.3 % CPU Time for "DWARF indexing worker": wall 0.592, user 0.459, sys 0.113, user+sys 0.572, 96.6 % CPU Time for "DWARF indexing worker": wall 0.739, user 0.608, sys 0.115, user+sys 0.723, 97.8 % CPU Time for "DWARF indexing worker": wall 0.831, user 0.677, sys 0.140, user+sys 0.817, 98.3 % CPU Time for "DWARF indexing worker": wall 0.949, user 0.789, sys 0.144, user+sys 0.933, 98.3 % CPU The object is only enabled if per_command_time (controlled by "maint set per-command time") is true at construction time. I wanted to avoid adding a new command for now, but eventually if there are too many scoped_time_it around the code base and we want to be able to enabled them selectively (e.g. just the ones in the DWARF reader, or in the symbol searching functions, etc), we could have a dedicated command for that. I added this functionality to GDB because it relies on gdb_printf and per_command_time, but if we ever need it in gdbsupport, I'm sure we could find a way to put it there. Change-Id: I5416ac1448f960f44d85f8449943d994198a271e Approved-By: Tom Tromey <tom@tromey.com>
2025-04-29gdbsupport: move run_time_clock::now(user, system) out of run_time_clockSimon Marchi1-1/+1
It is completely unrelated to run_time_clock, so I don't think it makes sense to have it as a static function there. Move it to be a free function named "get_run_time". Change-Id: I0c3e4d3cc44ca37e523c94d72f7cd66add95645e Approved-By: Tom Tromey <tom@tromey.com>
2025-04-29Handle base type without DW_AT_byte_sizeTom Tromey3-30/+59
DWARF says that a base type can have DW_AT_bit_size, without DW_AT_byte_size. However, gdb does not correctly handle this; in fact, it crashes, as pointed out in this LLVM merge request: https://github.com/llvm/llvm-project/pull/137123 This patch reworks the base type size logic a bit to handle this situation. Tested-by: Kevin Buettner <kevinb@redhat.com> Approved-by: Kevin Buettner <kevinb@redhat.com>
2025-04-29[gdb/contrib] Add script to license check new filesKeith Seitz1-0/+149
While reading through gdb-patches backlog after a return from PTO, I noticed that a newly added file was licensed with "MIT", and that license was not listed in Fedora's gdb.spec file. [Fedora no longer supports "effective" licenses.] That lead me to this simple script which generates a list of all the newly added files between two given commits and scans these files for licenses. Example usage: bash$ cd /path/to/binutils-gdb/gdb bash$ ./contrib/license-check-new-files.sh -s gdb-15-branchpoint gdb-16-branchpoint Scanning directories gdb*/... gdb/contrib/common-misspellings.txt: no longer in repo? gdb/contrib/spellcheck.sh: no longer in repo? gdbsupport/unordered_dense.h: MIT I don't think anything in here is Fedora- or RPM-specific, so I'd like to submit this for consideration for inclusion in contrib/. I believe other distros may find it useful. Approved-By: Tom Tromey <tom@tromey.com>
2025-04-29Change acronym BFD to Binary File Descriptor.Jeremy Bryant1-1/+1
This fixes a typo in gdb/README. Approved-By: Tom Tromey <tom@tromey.com>
2025-04-29[gdb/testsuite] Fix gdb.base/ptype.exp with gcc 15Tom de Vries1-4/+4
With test-case gdb.base/ptype.exp and gcc 15 I run into: ... (gdb) ptype old_fptr^M type = double (*)(void)^M (gdb) FAIL: $exp: ptype old_fptr (compiler doesn't emit unprototyped types) ... Since C23, non-prototype function declarations are no longer supported, so "double (*old_fptr) ()" is interpreted as "double (*old_fptr) (void)". We could try to fix this by detecting the language dialect used, and accepting the output in that case, but that feels fragile. We could try to fix this by hard-coding the language dialect, but that doesn't work for all compilers. So instead, we opt for the simplest solution: just accept this output, and produce a pass. Tested on aarch64-linux. Approved-By: Tom Tromey <tom@tromey.com> PR testsuite/32756 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32756
2025-04-29[gdb/testsuite] Fix gdb.python/py-objfile.exp with gcc 15Tom de Vries4-5/+8
When running test-case gdb.python/py-objfile.exp with gcc 15, we get: ... (gdb) p main^M $2 = {int (void)} 0x40066c <main>^M (gdb) FAIL: $exp: print main with debug info ... The source file declares main as "int main ()" ... and until C23 this meant a non-prototype function declaration and we'd have: ... (gdb) p main^M $2 = {int ()} 0x40066c <main>^M ... However, starting C23 "int main ()" is simply equivalent to "int main (void)". Fix this by: - declaring main as "int main (void)" in the test-case, and - updating the regexp to expect an "int (void)" prototype. Likewise in gdb.base/jit-bfd-name.exp. Tested on aarch64-linux. Approved-By: Tom Tromey <tom@tromey.com> PR testsuite/32756 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32756
2025-04-29[gdb/testsuite] Don't use string_to_regexp twice in gdb.base/options.expTom de Vries1-2/+1
In test-case gdb.base/options.exp, in proc test_completer_recognizes we have: ... set expected_re [string_to_regexp $input_line] test_gdb_complete_unique $input_line $expected_re ... However, the first thing we do in proc test_gdb_complete_unique is to apply string_to_regexp to the second argument: ... proc test_gdb_complete_unique { input_line complete_line {append_char " "} {max_completions false} {testname ""} } { set complete_line_re [string_to_regexp $complete_line] test_gdb_complete_unique_re \ $input_line \ $complete_line_re \ $append_char \ $max_completions\ $testname } ... This happens to not cause any FAILs at the moment, but this should be done only once. Fix this not using string_to_regexp in proc test_completer_recognizes. Tested on x86_64-linux. Approved-By: Tom Tromey <tom@tromey.com>
2025-04-29[gdb] Handle nullptr gdb_std{err,out} in {gdbpy,ioscm}_flushTom de Vries2-5/+14
Using the trigger patch described in the previous commit, I get: ... $ gdb (gdb) <q>error detected on stdin Fatal signal: Segmentation fault ----- Backtrace ----- 0x64c7b3 gdb_internal_backtrace_1 /data/vries/gdb/src/gdb/bt-utils.c:127 0x64c937 _Z22gdb_internal_backtracev /data/vries/gdb/src/gdb/bt-utils.c:196 0x94db83 handle_fatal_signal /data/vries/gdb/src/gdb/event-top.c:1021 0x94dd48 handle_sigsegv /data/vries/gdb/src/gdb/event-top.c:1098 0x7f372be578ff ??? 0x10b7c0a _Z9gdb_flushP7ui_file /data/vries/gdb/src/gdb/utils.c:1527 0xd4b938 gdbpy_flush /data/vries/gdb/src/gdb/python/python.c:1624 0x7f372d73b276 _PyCFunction_FastCallDict Objects/methodobject.c:231 0x7f372d73b276 _PyCFunction_FastCallKeywords Objects/methodobject.c:294 0x7f372d794a09 call_function Python/ceval.c:4851 0x7f372d78e838 _PyEval_EvalFrameDefault Python/ceval.c:3351 0x7f372d796e6e PyEval_EvalFrameEx Python/ceval.c:754 0x7f372d796e6e _PyFunction_FastCall Python/ceval.c:4933 0x7f372d796e6e _PyFunction_FastCallDict Python/ceval.c:5035 0x7f372d6fefc8 _PyObject_FastCallDict Objects/abstract.c:2310 0x7f372d6fefc8 _PyObject_Call_Prepend Objects/abstract.c:2373 0x7f372d6fe162 _PyObject_FastCallDict Objects/abstract.c:2331 0x7f372d700705 callmethod Objects/abstract.c:2583 0x7f372d700705 _PyObject_CallMethodId Objects/abstract.c:2640 0x7f372d812a41 flush_std_files Python/pylifecycle.c:699 0x7f372d81281d Py_FinalizeEx Python/pylifecycle.c:768 0xd4d49b finalize_python /data/vries/gdb/src/gdb/python/python.c:2308 0x9587eb _Z17ext_lang_shutdownv /data/vries/gdb/src/gdb/extension.c:330 0xfd98df _Z10quit_forcePii /data/vries/gdb/src/gdb/top.c:1817 0x6b3080 _Z12quit_commandPKci /data/vries/gdb/src/gdb/cli/cli-cmds.c:483 0x1056577 stdin_event_handler /data/vries/gdb/src/gdb/ui.c:131 0x1986970 handle_file_event /data/vries/gdb/src/gdbsupport/event-loop.cc:551 0x1986f4b gdb_wait_for_event /data/vries/gdb/src/gdbsupport/event-loop.cc:672 0x1985e0c _Z16gdb_do_one_eventi /data/vries/gdb/src/gdbsupport/event-loop.cc:263 0xb66f2e start_event_loop /data/vries/gdb/src/gdb/main.c:402 0xb670ba captured_command_loop /data/vries/gdb/src/gdb/main.c:466 0xb68b9b captured_main /data/vries/gdb/src/gdb/main.c:1344 0xb68c44 _Z8gdb_mainP18captured_main_args /data/vries/gdb/src/gdb/main.c:1363 0x41a3b1 main /data/vries/gdb/src/gdb/gdb.c:38 --------------------- A fatal error internal to GDB has been detected, further debugging is not possible. GDB will now terminate. This is a bug, please report it. For instructions, see: <https://www.gnu.org/software/gdb/bugs/>. Segmentation fault (core dumped) $ q ... Fix this in gdbpy_flush by checking for nullptr gdb_stdout/gdb_stderr (and likewise in ioscm_flush) such that we get instead: ... $ gdb (gdb) <q>error detected on stdin $ q ... Tested on x86_64-linux. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2025-04-29[gdb] Fix sig_write for null gdb_stderrTom de Vries2-7/+16
When running test-case gdb.tui/tui-layout-asm.exp with target board dwarf5-fission-debug-types, the test-case fails and I get a core dump: ... # of unexpected core files 1 ... Looking at the backtrace of the core file, what seems to be happening is that: - gdbpy_flush attempts to flush gdb_stdout, which is nullptr - that causes a segfault - gdb intercepts this and starts to handle it using handle_fatal_signal - handle_fatal_signal calls sig_write, which attempts to write to gdb_stderr, which is nullptr, - that causes another segfault - gdb exits I managed to reproduce the problem by the following trigger patch in stdin_event_handler: ... - if (error) + if (1 || error) { current_ui = main_ui; ui->unregister_file_handler (); - if (main_ui == ui) + if (1 || main_ui == ui) { gdb_printf (gdb_stderr, _("error detected on stdin\n")); + gdb_stderr = nullptr; + gdb_stdout = nullptr; + gdb_stdlog = nullptr; quit_command ((char *) 0, 0); } ... which gives us: ... $ gdb (gdb) <q>error detected on stdin Segmentation fault (core dumped) $ q ... Fix sig_write to handle the case that gdb_stderr == nullptr, such that we get instead: ... $ gdb (gdb) <q>error detected on stdin Fatal signal: Segmentation fault ----- Backtrace ----- ... --------------------- A fatal error internal to GDB has been detected, further debugging is not possible. GDB will now terminate. This is a bug, please report it. For instructions, see: <https://www.gnu.org/software/gdb/bugs/>. Segmentation fault (core dumped) $ q ... Tested on x86_64-linux. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2025-04-29[gdb] Factor out sig_writeTom de Vries3-25/+13
Lambda function sig_write: ... const auto sig_write = [] (const char *msg) -> void { gdb_stderr->write_async_safe (msg, strlen (msg)); } ... is defined a few times. Factor this out into a regular function. Tested on x86_64-linux. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2025-04-28Fix "set debug parser"Tom Tromey5-3/+29
While debugging my longer series, I discovered that I broken "set debug parser" a couple years ago. This patch fixes it and adds a minimal test case so that it, hopefully, will not break again. This patch also adds parser debugging to the C++ name canonicalizer. Thanks to Tom de Vries for fixing the test case.
2025-04-28Regenerate more configury files for 64-bit BFD detection fixMaciej W. Rozycki1-3/+0
The fix for 64-bit BFD detection omitted the regeneration of a bunch of configury files; fix that.
2025-04-28Fix 64-bit BFD detection causing build failuresMaciej W. Rozycki3-98/+42
We have a discrepancy with 64-bit BFD handling across our component subdirectories leading to link failures such as: ld: ../opcodes/.libs/libopcodes.a(disassemble.o): in function `disassembler': disassemble.c:(.text+0x65): undefined reference to `print_insn_alpha' ld: disassemble.c:(.text+0x105): undefined reference to `print_insn_ia64' ld: disassemble.c:(.text+0x11d): undefined reference to `print_insn_loongarch' ld: disassemble.c:(.text+0x1a1): undefined reference to `print_insn_big_mips' [...] with some configurations having a 32-bit host and 64-bit BFD, such as: `--host=i386-linux-gnu --target=riscv64-linux-gnu --enable-targets=all'. This is ultimately due to how 64-bit BFD is enabled for bfd/ itself and other subdirectorses and has been a regression from commit 1d5269c994bf ("unify 64-bit bfd checks"). For bfd/ the BFD_64_BIT autoconf macro from config/bfd64.m4 is used combined with this logic in bfd/configure.ac: case ${host64}-${target64}-${want64} in *true*) wordsize=64 bfd64_libs='$(BFD64_LIBS)' all_backends='$(BFD64_BACKENDS) $(BFD32_BACKENDS)' [...] ;; false-false-false) wordsize=32 all_backends='$(BFD32_BACKENDS)' ;; esac where the value of ${wordsize} switches between 32-bit and 64-bit BFD via these pieces: #define BFD_ARCH_SIZE @wordsize@ and: #if BFD_ARCH_SIZE >= 64 #define BFD64 #endif in bfd/bfd-in.h, which ultimately becomes a part of "bfd.h". Then ${host64} is determined in bfd/configure.ac from the host's word size, via the host's pointer size: if test "x${ac_cv_sizeof_void_p}" = "x8"; then host64=true fi And ${target64} is determined in bfd/configure.ac from the target's word size: if test ${target_size} = 64; then target64=true fi Where multiple targets have been requested with `--enable-targets=all' the presence of any 64-bit target will set "true" here. Finally ${want64} is set according to `--enable-64-bit-bfd' user option with an arrangement involving BFD_64_BIT: BFD_64_BIT if test $enable_64_bit_bfd = yes ; then want64=true else want64=false fi which also, redundantly, checks and sets its result upon the host's word size. Lastly ${want64} is also selectively set by target fragments in bfd/config.bfd, which mostly if not completely overlaps with ${target64} setting as described above. Conversely other subdirectories only rely on BFD_64_BIT, so they fail to notice that BFD is 64-bit and do not enable their 64-bit handling where the host requested is 32-bit and 64-bit BFD has been enabled other than with `--enable-64-bit-bfd'. One consequence is opcodes/disassemble.c enables calls to its numerous own 64-bit backends by checking the BFD64 macro from "bfd.h", however does not actually enable said backends in its Makefile. Hence the link errors quoted above. Address the problem then by moving the `--enable-64-bit-bfd' option back to bfd/configure.ac and remove the call to BFD_64_BIT from there and then rewrite the macro in terms of checking for the presence of BFD64 macro in "bfd.h", which is the canonical way of determining whether BFD is 64-bit or not. Rather than running `grep' directly on ../bfd/bfd-in3.h as the opcodes/ fragment used to before the problematic commit: if grep '#define BFD_ARCH_SIZE 64' ../bfd/bfd-in3.h > /dev/null; then run the preprocessor on "bfd.h", which allows to invoke the macro from configure.ac files placed in subdirectories located at deeper levels, by relying on the preprocessor's search path. This requires however that the invokers rely on `all-bfd' rather than `configure-bfd' for their `configure' invocation stage, because "bfd.h" is made by `make all' rather than `configure' in bfd/. Do not cache the result of this check however, as reconfiguring a tree such as to flip `--enable-64-bit-bfd' on or to change a secondary target may affect BFD64 and we have no access to information about secondary targets in BFD_64_BIT. Also remove the ENABLE_BFD_64_BIT automake conditional, as it's not used anywhere. Last but not least remove the hack from gdb/configure.ac to fail builds for `mips*-*-*' hosts where `--enable-targets=all' has been requested, but `--enable-64-bit-bfd' has not as it's no longer needed. Such builds complete successfully now, having enabled 64-bit BFD implicitly. Tested-By: Guinevere Larsen <guinevere@redhat.com> Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Alan Modra <amodra@gmail.com> Approved-By: Luis Machado <luis.machado@arm.com>
2025-04-28[gdb/testsuite] Avoid generating gdb_leak_detector.cpython-<n>.pycTom de Vries3-0/+18
After running test-case gdb.python/py-color-leak.exp in a container where I don't have PYTHONDONTWRITEBYTECODE set, I get: ... $ ls src/gdb/testsuite/gdb.python/__pycache__/ gdb_leak_detector.cpython-313.pyc ... Fix this by setting sys.dont_write_bytecode to True in the python scripts importing the module. Tested on x86_64-linux.
2025-04-26Add "maint canonicalize" commandTom Tromey4-0/+34
This adds a new "maint canonicalize" command that can be used to see the canonical form of a C++ name. I've needed this a few times when debugging gdb. Reviewed-By: Eli Zaretskii <eliz@gnu.org> Reviewed-By: Tom de Vries <tdevries@suse.de>
2025-04-26[gdb/contrib] Add codespell:ignore-begin/ignore-end (disabled)Tom de Vries1-0/+9
It would be useful to tell codespell to ignore blocks of code. A feature ignore-multiline-regex exists, which can be used to implement this: ... $ codespell --ignore-multiline-regex \ 'codespell:ignore-begin.*codespell:ignore-end' ... Unfortunately there's a bug in codespell where using -w in combination with --ignore-multiline-regex drops all newlines in the updated file. In absence of a fix, commit this solution disabled, to locally document the current state of this feature.
2025-04-25[pre-commit] Add codespell-log commit-msg hookTom de Vries1-0/+95
Now that we're using codespell to check spelling in gdb files, can we use codespell to bring this spelling warning: ... $ echo usuable | codespell - 1: usuable usuable ==> usable ... to: ... $ git commit -a -m "Usuable stuff" ... ? First, let's look at a straightforward commit-msg hook implementation: ... - id: codespell name: codespell-commit-msg verbose: true always_run: true stages: [commit-msg] ... installed using: ... $ pre-commit install -t commit-msg ... When trying the commit, we get: ... $ echo "/* bla */" >> gdb/gdb.c $ git commit -a -m "Usuable stuff" black................................................(no files to check)Skipped flake8...............................................(no files to check)Skipped isort................................................(no files to check)Skipped codespell............................................(no files to check)Skipped check-include-guards.................................(no files to check)Skipped black................................................(no files to check)Skipped flake8...............................................(no files to check)Skipped codespell............................................(no files to check)Skipped codespell-commit-msg.....................................................Failed - hook id: codespell - duration: 0.06s - exit code: 65 .git/COMMIT_EDITMSG:1: Usuable ==> Usable check-include-guards.................................(no files to check)Skipped $ ... The commit was aborted, but the commit message is still there: ... $ cat .git/COMMIT_EDITMSG Usuable stuff ... We can retry and edit the commit message to clean up the typo: ... $ git commit -e -F .git/COMMIT_EDITMSG -a ... but it's a bit cumbersome. Furthermore, say we fix a typo and want to document this in the commit log, and do: ... $ git commit -m "Fixed typo: useable -> usable" -a ... This commit cannot succeed, unless we add a codespell ignore tag, which feels like taking it too far. Both these problems can be addressed by setting things up in such a way that the commit always succeeds, and codespell output is shown as a hint. Ideally, we'd tell to pre-commit to implement this using some setting, but there doesn't seem to be one. So we use some indirection. Instead of using native codespell, use a local hook that calls a script gdb/contrib/codespell-log.sh, which calls pre-commit, which calls codespell. Using this approach, we get: ... $ echo "/* bla */" >> gdb/gdb.c $ git commit -a -m "Usuable stuff" black................................................(no files to check)Skipped flake8...............................................(no files to check)Skipped isort................................................(no files to check)Skipped codespell............................................(no files to check)Skipped check-include-guards.................................(no files to check)Skipped black................................................(no files to check)Skipped flake8...............................................(no files to check)Skipped codespell............................................(no files to check)Skipped check-include-guards.................................(no files to check)Skipped codespell-log............................................................Passed - hook id: codespell-log - duration: 0.18s codespell-log-internal...................................................Failed - hook id: codespell - exit code: 65 .git/COMMIT_EDITMSG:1: Usuable ==> Usable [codespell/codespell-log-2 d081bd25a40] Usuable stuff 1 file changed, 1 insertion(+) $ ... This is obviously convoluted, but it works. Perhaps we can propose a pre-commit improvement (always_pass) and simplify this eventually. Checked new script codespell-log.sh with shell-check. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2025-04-25gdb: fix 32 bit buildGuinevere Larsen1-1/+1
The recent commit dbbb9cfd3708a5b09b449c6cbc4d74dfec13904d added a message using %ld to print an std::vector::size, which is of size_t type. on 64 bit machines, size_t will be an unsigned long int, making %ld work just fine, but on 32 bit ones, size_t will be unsigned int, which causes the build to fail. This commit fixes that by using %zu instead. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32901 Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Luis Machado <luis.machado@arm.com>
2025-04-25Revert "gdb: update corner case when canonicalizing riscv syscall names"Guinevere Larsen1-1/+1
This reverts commit b2aba1ce1326df73c03641e1cb01d2c5aa577015. That commit was pushed in error, as I confused which patch was approved in the list
2025-04-24gdb/dwarf: add dwarf2_cu::find_die methodSimon Marchi2-5/+13
I added this small helper method in the series I'm writing, to make finding a DIE by section offset a bit nicer than using the unordered_set methods. It doesn't have any dependencies, so I thought I would submit it on its own. Change-Id: If7313194ab09d9bd6d6a52c24eb6fd9a9c1b76e0 Approved-by: Kevin Buettner <kevinb@redhat.com>
2025-04-24gdb: fix some flake8 F824 warningsSimon Marchi12-36/+2
flake8 7.2.0 appears to have this new warning: F824: global name / nonlocal name is unused: name is never assigned in scope It points out a few places in our code base where "global" is not necessary, fix them. Change-Id: Ia6fb08686977559726fefe2a5bb95d8dcb298bb0 Approved-By: Tom Tromey <tom@tromey.com>
2025-04-24Use correct sign extension for enumeration typesTom Tromey1-22/+37
This changes update_enumeration_type_from_children to use the correct sign-extension method on the attribute. The logic here is a bit complicated: if the enum has an underlying type, then we use that type's signed-ness to interpret attributes; otherwise we must assume attributes are encoded as signed values. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24Use bool in update_enumeration_type_from_childrenTom Tromey1-6/+6
This is just a small preliminary cleanup to use 'bool' in update_enumeration_type_from_children.
2025-04-24Remove dead code from dwarf2_const_value_dataTom Tromey1-35/+16
dwarf2_const_value_data checks the size of the data like so: if (bits < sizeof (*value) * 8) ... else if (bits == sizeof (*value) * 8) ... else ... However, 'bits' can only be 8, 16, 32, or 64. And, because 'value' is a LONGEST, which is alwasy 64-bit, the final 'else' can never be taken. This patch removes the dead code. And, because this was the only reason for a non-void return value, the return type is changed as well. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24Use attribute::signed_constant in attribute::as_booleanTom Tromey1-1/+4
This changes attribute::as_boolean to use attribute::signed_constant. This is maybe overkill but lets any reasonable constant form through. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24Use correct sign for variant part discriminantsTom Tromey1-10/+24
The discriminant value for a variant part may be signed or unsigned, depending on the type of the variant. This patch changes the DWARF reader to delay interpretation of the relevant attribute until the signed-ness is known. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24Use correct sign in get_mpzTom Tromey2-2/+11
This changes dwarf2/read.c:get_mpz to use the correct sign-extension function. Normally a rational constant uses signed values, but a purely unsigned form also seems fine here. This adds a new attribute::form_is_strictly_unsigned, which is more precise than form_is_unsigned (which accepts a lot of forms that aren't really for ordinary constants). Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24Use attribute::unsigned_constant for DW_AT_data_member_locationTom Tromey1-3/+3
This changes the DWARF reader to use attribute::unsigned_constant for DW_AT_data_member_location. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24Use attribute::unsigned_constant for DW_AT_data_bit_offsetTom Tromey1-10/+16
This changes the DWARF reader to use attribute::unsigned_constant when examining DW_AT_data_bit_offset. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24Use correct sign for DW_AT_GNU_biasTom Tromey1-2/+7
DW_AT_GNU_bias may be signed or unsigned, depending on the underlying type. This patch changes the DWARF reader to examine the type before decoding the attribute. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24Use attribute::unsigned_constant for DW_AT_bit_strideTom Tromey1-1/+1
DW_AT_bit_stride uses an unsigned constant, so make this explicit in the reader. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24Use attribute::signed_constant for fixed-point scaleTom Tromey1-2/+2
This changes the DWARF reader to use attribute::signed_constant for DW_AT_binary_scale and DW_AT_decimal_scale. (FWIW these were the attributes that first lead me to find this problem.) Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24Introduce attribute::signed_constantTom Tromey2-0/+39
This introduces a new method, attribute::signed_constant. This should be used wherever DWARF specifies a signed integer constant, or where this is implied by the context. It properly handles sign-extension for DW_FORM_data*. To my surprise, there doesn't seem to be a pre-existing sign-extension function. I've added one to common-utils.h alongside the align functions. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24Use attribute::unsigned_constant for sizesTom Tromey1-17/+16
This changes the DWARF reader to use attribute::unsigned_constant for DW_AT_bit_size, DW_AT_byte_size, DW_AT_data_byte_size, and DW_AT_string_length. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
2025-04-24gdb: update corner case when canonicalizing riscv syscall namesGuinevere Larsen1-1/+1
The script syscalls/riscv-canonicalize-syscall-gen.py has been recently introduced to help support record-full in riscv systems. However, it was developed before commit 432eca4113d5748ad284a068873455f9962b44fe, which made the GDB enum more consistent, which forced the python script to have a corner case for the "gdb_old_mmap" case. Since the aforementioned commit has already been merged, we need to update the special case for the mmap syscall. A special case is still needed because the script would expect that the glibc sources call the syscall "old_mmap", or that gdb call it "gdb_sys_mmap", neither of which happens unfortunately. This commit doesn't change the .c file because it was already fixed by a different commit, 65ab41b7d5c612b6000b28f4c50bb256b2a9e22b, which was pushed as obvious to fix the build issues. Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Luis Machado <luis.machado@arm.com>
2025-04-24Fix documentation for gdb.blocked_signalsTom Tromey1-5/+5
gdb exports a context manager named gdb.blocked_signals, but the documentation erroneously refers to it as gdb.block_signals. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32891 Approved-By: Eli Zaretskii <eliz@gnu.org> Approved-By: Tom de Vries <tdevries@suse.de>
2025-04-24Add TLS NEWS entry and document 'set force-internal-tls-address-lookup' commandKevin Buettner2-0/+70
Reviewed-By: Eli Zaretskii <eliz@gnu.org> Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Luis Machado <luis.machado@arm.com>
2025-04-24New test - gdb.base/tls-dlobj.expKevin Buettner3-0/+776
This test exercises musl_link_map_to_tls_module_id() and glibc_link_map_to_tls_module_id(), both of which are in solib-svr4.c. Prior to writing this test, I had only written what is now named 'musl_link_map_to_tls_module_id' and it worked for both GLIBC and MUSL. Once I wrote this new test, tls-dlobj.exp, there were a number of tests which didn't work with GLIBC. This led me to write a GLIBC-specific link map to module id function, i.e, 'glibc_link_map_to_tls_module_id'. It only has one compilation scenario, in which the pthread(s) library is used - as noted in a comment, it became too much of a hassle to try to KFAIL things, though it certainly could have been done in much the same was as was done in gdb.base/multiobj.exp. It didn't seem that important to do so, however, since I believe that the other tests have adequate coverage for different compilation scenarios. Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Luis Machado <luis.machado@arm.com>
2025-04-24New test - gdb.base/tls-multiobj.expKevin Buettner5-0/+397
This test exercises GDB's internal TLS support when both the main program and several shared libraries have TLS variables. It also tests existing (non-internal) TLS support too. It tests using two compilation scenarios, "default", in which libpthread is not linked with the program and libraries as well as one which does use libpthread. It tests link map address to module id mapping code in GDB in addition to the ability of GDB to traverse TLS data structures with several libraries in play. Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Luis Machado <luis.machado@arm.com>
2025-04-24New test - gdb.base/tls-nothreads.expKevin Buettner3-0/+355
This commit introduces a new test, gdb.base/tls-nothreads.exp. It has a test case, a C file, which has several TLS variables in the main program, which, once compiled and linked, should end up (in ELF files) in .tdata and .tbss. The test compiles the program in a number of different ways, making sure that each variable is accessible regardless of how it was compiled. Note that some of the compilation scenarios end up with a statically linked executable. Prior to this series of commits, accessing TLS variables from a statically linked program on Linux did not work. For certain targets (x86_64, aarch64, s390x, riscv, and ppc64), all on Linux, support has been added to GDB for accessing thread local storage in statically linked executables. This test is important for testing those build scenarios. But it's also important to make sure that GDB's internal TLS support works for other scenarios too. In order to accomplish that, the tests are also run in a mode which forces the internal support to be used. It also adds a new file, gdb.base/tls-common.exp.tcl, which includes some common definitions used by the three new TLS tests, including the one added by this commit. In particular, it sets a TCL variable, 'internal_tls_linux_targets' which list the targets mentioned earlier. This means that as internal TLS support is added for other targets, the target should be listed in just one file as opposed to three (or more if other tests using tls-common.exp.tcl are added). Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Luis Machado <luis.machado@arm.com>
2025-04-24Delete disabled i386 internal TLS supportKevin Buettner1-46/+0
As mentioned in the previous commit, this commit deletes the disabled code which could be used to implement internal TLS support for the i386 target. Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Luis Machado <luis.machado@arm.com>
2025-04-24Internal, but disabled, TLS support for i386Kevin Buettner1-0/+46
This commit shows how internal TLS address lookup support could be implemented for the i386 target. Unfortunately, it doesn't work due to I386_GSBASE_REGNUM being unavailable for Linux targets. I looked at trying to access the gsbase register via PTRACE_GET_THREAD_AREA, but did not understand it well enough to finish it. Since the i386 target is much less important than it used to be, I gave up working on it. I don't want to leave this disabled code in our sources, so I will delete it in the next commit, however, this commit will be in our git repo, so it'll be available for someone with sufficient interest in the i386 target to look at. Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Luis Machado <luis.machado@arm.com>
2025-04-24Internal TLS support for aarch64, x86_64, riscv, ppc64, and s390xKevin Buettner6-5/+286
For each architecture, aarch64, x86_64, riscv, ppc64, and s390x, this commit defines a suitable 'get_tls_dtv_addr' method and, when necessary, a 'get_tls_dtp_offset' method. It also registers svr4_tls_get_thread_local_address, defined in svr4-tls-tdep.c (in an earlier commit), as the get_thread_local_address gdbarch method. It also registers its architecture specific code using svr4_tls_register_tls_methods(). Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=24548 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31563 Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Luis Machado <luis.machado@arm.com>
2025-04-24Implement internal TLS address lookup for select Linux targetsKevin Buettner4-0/+319
This commit adds non-architecture-specific support for internal TLS address lookup for targets which register their support with the new file svr4-tls-tdep.c. By "internal", I mean support which does not rely on libthread_db. Knowledge of how to traverse TLS data structures is contained in this commit along with the next commit containing architecture specific knowledge regarding TLS offsets, registers, and such. The new function 'svr4_tls_get_thread_local_address' is a gdbarch method. It should be passed as an argument to set_gdbarch_get_thread_local_address in architecture specific <arch>-linux-tdep.c files which wish to offer internal TLS support. The architecture specific tdep files need to define a get_tls_dtv_addr method - as the name suggests, it needs to return the address of the DTV (dynamic thread vector) via architecture specific means. This usually entails fetching the thread pointer via a register or registers assigned to this purpose, and then using that value to locate the address of the DTV from within the TCB (thread control block). Additionally, some architectures also need to provide a DTP offset, which is used by the MUSL C library to adjust the value obtained from a DTV entry to that of the start of the TLS block for a particular thread. This is provided, when necessary, by a get_tls_dtp_offset method. Both methods, get_tls_dtv_addr and get_tls_dtp_offset, are registered with data structures maintained by linux-tdep.c via the new function svr4_tls_register_tls_methods(). Thus, for example, on RISC-V, riscv_linux_init_abi() will make the following two calls, the first for registering the internal get_thread_local_address gdbarch method and the second for registering riscv-specific methods for obtaining the DTV address and DTP offset: set_gdbarch_get_thread_local_address (gdbarch, svr4_tls_get_thread_local_address); svr4_tls_register_tls_methods (info, gdbarch, riscv_linux_get_tls_dtv_addr, riscv_linux_get_tls_dtp_offset); Internal TLS support is provided for two C libraries, GLIBC, and MUSL. Details for accessing the various TLS data structures differ between these libraries. As a consequence, linux-tdep.h defines a new enum, svr4_tls_libc, with values svr4_tls_libc_unknown, svr4_tls_libc_musl, and svr4_tls_libc_glibc. A new static function libc_tls_sniffer uses heuristics to (try to) decide whether a program was linked against GLIBC or MUSL. Working out what the heuristics should be, especially for statically linked binaries, turned out to be harder than I thought it would be. A new maintenance setting, force-internal-tls-address-lookup, has been added, which, when set to 'on', will (as the name suggests) force the internal TLS lookup mechanisms to be used. Otherwise, if thread_db support is available (via the thread stratum), that will be preferred since it should be more accurate. I expect that this setting will be mostly used by test cases in the GDB test suite. The new test cases that are part of this series all use it, with iterations using both 'on' and 'off' for all of the tests therein. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=24548 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31563 Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Luis Machado <luis.machado@arm.com>
2025-04-24Track and fetch TLS module ids for MUSL and GLIBCKevin Buettner2-4/+220
This commit adds, to solib-svr4.h and solib-svr4.c, functions glibc_link_map_to_tls_module_id and musl_link_map_to_tls_module_id for use with callers in a new file svr4-tls-tdep.c (which is not in this commit). It adds a number of helper functions for implementing link map to module id support. It also renames existing function 'find_program_interpreter' to 'svr4_find_program_interpreter' and makes it visible to other source files within GDB. It will be used in the libc sniffing code in svr4-tls-tdep.c in a later commit in this series. The libc sniffer is needed in order to know which link map to module id function to call as the method for determining module ids differs between libc / dynamic linker implementations. These details are discussed in comments in the patch. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=24548 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31563 Tested-By: Luis Machado <luis.machado@arm.com> Approved-By: Luis Machado <luis.machado@arm.com>