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2022-02-28Handle multi-byte bracket sequences in Ada lexerTom Tromey6-21/+52
As noted in an earlier patch, the Ada lexer does not handle multi-byte bracket sequences. This patch adds support for these for character literals. gdb does not generally seem to handle the Ada wide string types, so for the time being these continue to be excluded -- but an explicit error is added to make this more clear.
2022-02-28Handle 'QWW' encoding case in Ada enumsTom Tromey5-3/+125
In Ada, an enum can contain character literals. GNAT encodes these values in a special way. For example, the Unicode character U+0178 would be represented as 'QW0178' in the DWARF: <3><112f>: Abbrev Number: 2 (DW_TAG_enumerator) <1130> DW_AT_name : (indirect string, offset: 0x19ff): QW0178 <1134> DW_AT_const_value : 2 gdb handles this reasonably well, but failed to handle the 'QWW' encoding, which is used for characters outside the base plane. Also, while working on this, I noticed that gdb will print the decimal value for an enum character constant: (gdb) print Char_X $2 = 1 'x' This is a nice feature, IMO, because in this situation the 'x' enum constant does not have its usual decimal value -- it has the value that's assigned based on the enumeration type. However, gdb did not do this when it decided to print the constant using the bracket notation: (gdb) print Char_Thorn $3 = ["de"] This patch changes gdb to print the decimal value here as well, and to put the bracket notation in single quotes -- otherwise gdb will be printing something that it can't then read. Now it looks like: (gdb) print Char_Thorn $3 = 4 '["de"]' Note that gdb can't read longer bracket notations, like the other ones printed in this test case: (gdb) print Char_King $4 = 3 '["01fa00"]' While I think this is a bug, I plan to fix it separately. Finally, in the new test case, the copyright dates are chosen this way because this all started as a copy of an existing test.
2022-02-28gdb/python: Add gdb.InferiorThread.details attributeAndrew Burgess5-0/+58
This adds a new read-only attribute gdb.InferiorThread.details, this attribute contains a string, the results of target_extra_thread_info for the thread, or None, if target_extra_thread_info returns nullptr. As the string returned by target_extra_thread_info is unstructured, this attribute is only really useful for echoing straight through to the user, but, if a user wants to write a command that displays the same, or a similar 'Thread Id' to the one seen in 'info threads', then they need access to this string. Given that the string produced by target_extra_thread_info varies by target, there's only minimal testing of this attribute, I check that the attribute can be accessed, and that the return value is either None, or a string.
2022-02-28Error when gdb_is_target_1 is called without running gdb instanceKeith Seitz1-0/+15
This is a snafu that I encountered while implementing the previous patch, which attempted to use gdb_is_target_native. This proc and gdb_is_target_remote both rely on gdb_is_target_1, which actually cannot be called without gdb already running. This patch adds appropriate warning comments to these procs and causes gdb_is_target_1 to issue a Tcl error if it is called without a gdb instance already running. This should prevent unwitting callers from using this at the wrong time.
2022-02-28Fix gdb.fortran "failed to extract expected results" errorsKeith Seitz2-0/+12
When running the gdb.fortran tests array-slices.exp and lbound-ubound.exp, the test suite throws several ERRORs on native-gdbserver/-m{32,64}, and native-extended-gdbsever/-m{32,64}: [on native-extended-gdbserver/-m64] Running /home/keiths/work/gdb/branches/testsuite-errors/linux/gdb/testsuite/../../../src/gdb/testsuite/gdb.fortran/array-slices.exp ... ERROR: failed to extract expected results ERROR: failed to extract expected results Running /home/keiths/work/gdb/branches/testsuite-errors/linux/gdb/testsuite/../../../src/gdb/testsuite/gdb.fortran/lbound-ubound.exp ... ERROR: failed to extract expected results for lbound This occurs because the tests require inferior I/O which we do not have access to while using these targets. This patch skips these tests when running on non-native targets.
2022-02-26Handle recursive internal problem in gdb_internal_error_resyncKevin Buettner1-0/+4
I came across this problem when testing gdb.base/gdb-sigterm.exp on a machine with a pre-release version of glib-2.34 installed: A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) Recursive internal problem. FAIL: gdb.base/gdb-sigterm.exp: expect eof #0 (GDB internal error) Resyncing due to internal error. ERROR: : spawn id exp11 not open while executing "expect { -i exp11 -timeout 10 -re "Quit this debugging session\\? \\(y or n\\) $" { send_gdb "n\n" answer incr count } -re "Create..." ("uplevel" body line 1) invoked from within "uplevel $body" NONE : spawn id exp11 not open ERROR: Could not resync from internal error (timeout) gdb.base/gdb-sigterm.exp: expect eof #0: stepped 9 times UNRESOLVED: gdb.base/gdb-sigterm.exp: 50 SIGTERM passes I don't have a problem with the latter ERROR nor the UNRESOLVED messages. However the first ERROR regarding the exp11 spawn id not being open is not especially useful. This commit handles the "Recursive internal problem" case, avoiding the problematic ERROR shown above. With this commit in place, the log messages look like this instead: A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) Recursive internal problem. FAIL: gdb.base/gdb-sigterm.exp: expect eof #15 (GDB internal error) Resyncing due to internal error. ERROR: Could not resync from internal error (recursive internal problem) gdb.base/gdb-sigterm.exp: expect eof #15: stepped 12 times UNRESOLVED: gdb.base/gdb-sigterm.exp: 50 SIGTERM passes gdb/testsuite/ChangeLog: * lib/gdb.exp (gdb_internal_error_resync): Handle "Recursive internal problem".
2022-02-25gdb-add-index: disable debuginfodAaron Merey1-0/+1
gdb-add-index may trigger debuginfod's first-use notice. The notice is misleading in this case. It instructs the user to modify .gdbinit in order to permanently enable/disable debuginfod but gdb-add-index invokes gdb with -nx which ignores .gdbinit. Additionally debuginfod is not needed for gdb-add-index since the symbol file is given as an argument and should already be present locally. Fix this by disabling debuginfod when gdb-add-index invokes gdb.
2022-02-25gdb: add operator+= and operator+ overload for std::stringAndrew Burgess3-3/+61
This commit adds operator+= and operator+ overloads for adding gdb::unique_xmalloc_ptr<char> to a std::string. I could only find 3 places in GDB where this was useful right now, and these all make use of operator+=. I've also added a self test for gdb::unique_xmalloc_ptr<char>, which makes use of both operator+= and operator+, so they are both getting used/tested. There should be no user visible changes after this commit, except when running 'maint selftest', where the new self test is visible.
2022-02-25Print MI prompt on interrupted commandTom Tromey1-0/+11
Joel noticed that if the remote dies unexpectedly during a command -- you can simulate this by using "continue" and then killing gdbserver -- then the CLI will print a new prompt, but MI will not. Later, we found out that this was also filed in bugzilla as PR mi/23820. The output looks something like this: | (gdb) | cont | &"cont\n" | ~"Continuing.\n" | ^running | *running,thread-id="all" | (gdb) | [... some output from GDB during program startup...] | =thread-exited,id="1",group-id="i1" | =thread-group-exited,id="i1" | &"Remote connection closed\n" Now, what about that "(gdb)" in the middle? That prompt comes from this questionable code in mi-interp.c:mi_on_resume_1: /* This is what gdb used to do historically -- printing prompt even if it cannot actually accept any input. This will be surely removed for MI3, and may be removed even earlier. */ if (current_ui->prompt_state == PROMPT_BLOCKED) fputs_unfiltered ("(gdb) \n", mi->raw_stdout); ... which seems like something to remove. But maybe the intent here is that this prompt is sufficient, and MI clients must be ready to handle output coming after a prompt. On the other hand, if this code *is* removed, then nothing would print a prompt in this scenario. Anyway, the CLI and the TUI handle emitting the prompt here by hooking into gdb::observers::command_error, but MI doesn't install an observer here. This patch adds the missing observer and arranges to show the MI prompt. Regression tested on x86-64 Fedora 34. It seems like this area could be improved a bit, by having start_event_loop call the prompt-displaying code directly, rather than indirecting through an observer. However, I haven't done this. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=23820
2022-02-25gdb/testsuite: fix list.exp test casesAndrew Burgess1-50/+31
PR testsuite/7142 -- old enough to have been converted from Gnats -- points out that test_list_filename_and_function in gdb.base/list.exp has "fails" that are unmatched with passes. This patch cleans this up a little. Co-authored-by: Tom Tromey <tromey@adacore.com> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=7142
2022-02-24Support template lookups in strncmp_iw_with_modeKeith Seitz10-40/+800
This patch adds support for wild template parameter list matches, similar to how ABI tags or function overloads are now handled. With this patch, users will be able to "gloss over" the details of matching template parameter lists. This is accomplished by adding (yet more) logic to strncmp_iw_with_mode to skip parameter lists if none is explicitly given by the user. Here's a simple example using gdb.linespec/cpls-ops.exp: Before ------ (gdb) ptype test_op_call type = struct test_op_call { public: void operator()(void); void operator()(int); void operator()(long); void operator()<int>(int *); } (gdb) b test_op_call::operator() Breakpoint 1 at 0x400583: test_op_call::operator(). (3 locations) (gdb) i b Num Type Disp Enb Address What 1 breakpoint keep y <MULTIPLE> 1.1 y 0x400583 in test_op_call::operator()(int) at cpls-ops.cc:43 1.2 y 0x40058e in test_op_call::operator()() at cpls-ops.cc:47 1.3 y 0x40059e in test_op_call::operator()(long) at cpls-ops.cc:51 The breakpoint at test_op_call::operator()<int> was never set. After ----- (gdb) b test_op_call::operator() Breakpoint 1 at 0x400583: test_op_call::operator(). (4 locations) (gdb) i b Num Type Disp Enb Address What 1 breakpoint keep y <MULTIPLE> 1.1 y 0x400583 in test_op_call::operator()(int) at cpls-ops.cc:43 1.2 y 0x40058e in test_op_call::operator()() at cpls-ops.cc:47 1.3 y 0x40059e in test_op_call::operator()(long) at cpls-ops.cc:51 1.4 y 0x4008d0 in test_op_call::operator()<int>(int*) at cpls-ops.cc:57 Similar to how scope lookups work, passing "-qualified" to the break command will cause a literal lookup of the symbol. In the example immediately above, this will cause GDB to only find the three non-template functions.
2022-02-24Unit tests for strncmp_iw_with_modeKeith Seitz1-0/+565
This patch attempts to make a start at adding unit tests for strncmp_iw_with_mode. While there is quite a bit of testing of this function in other tests, these are currently end-to-end tests. This patch attempts to cover the basics of string matching, white space, C++ ABI tags, and several other topics. However, one area that is ostensibly missing is testing the `match_for_lcd' feature. This is otherwise tested as part of our end-to-end DejaGNU-based testing.
2022-02-24Move find_toplevel_char to cp-support.[ch]Keith Seitz4-84/+81
find_toplevel_char is being used more and more outside of linespec.c, so this patch moves it into cp-support.[ch].
2022-02-24Fix crash in Fortran codeTom Tromey3-2/+208
PR fortran/28801 points out a gdb crash that can be provoked by certain Fortran code. The bug is that f77_get_upperbound assumes the property is either a constant or undefined, but in this case it is PROP_LOCEXPR. This patch fixes the crash by making this function (and the lower-bound one as well) do the correct check before calling 'const_val'. Thanks to Andrew for writing the test case. Co-authored-by: Andrew Burgess <aburgess@redhat.com> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28801
2022-02-24Revert "do_target_wait_1: Clear TARGET_WNOHANG if the target isn't async."John Baldwin1-1/+1
Commit 14b3360508b1 ("do_target_wait_1: Clear TARGET_WNOHANG if the target isn't async.") broke some multi-target tests, such as gdb.multi/multi-target-info-inferiors.exp. The symptom is that execution just hangs at some point. What happens is: 1. One remote inferior is started, and now sits stopped at a breakpoint. It is not "async" at this point (but it "can async"). 2. We run a native inferior, the event loop gets woken up by the native target's fd. 3. In do_target_wait, we randomly choose an inferior to call target_wait on first, it happens to be the remote inferior. 4. Because the target is currently not "async", we clear TARGET_WNOHANG, resulting in synchronous wait. We therefore block here: #0 0x00007fe9540dbb4d in select () from /usr/lib/libc.so.6 #1 0x000055fc7e821da7 in gdb_select (n=15, readfds=0x7ffdb77c1fb0, writefds=0x0, exceptfds=0x7ffdb77c2050, timeout=0x7ffdb77c1f90) at /home/simark/src/binutils-gdb/gdb/posix-hdep.c:31 #2 0x000055fc7ddef905 in interruptible_select (n=15, readfds=0x7ffdb77c1fb0, writefds=0x0, exceptfds=0x7ffdb77c2050, timeout=0x7ffdb77c1f90) at /home/simark/src/binutils-gdb/gdb/event-top.c:1134 #3 0x000055fc7eda58e4 in ser_base_wait_for (scb=0x6250002e4100, timeout=1) at /home/simark/src/binutils-gdb/gdb/ser-base.c:240 #4 0x000055fc7eda66ba in do_ser_base_readchar (scb=0x6250002e4100, timeout=-1) at /home/simark/src/binutils-gdb/gdb/ser-base.c:365 #5 0x000055fc7eda6ff6 in generic_readchar (scb=0x6250002e4100, timeout=-1, do_readchar=0x55fc7eda663c <do_ser_base_readchar(serial*, int)>) at /home/simark/src/binutils-gdb/gdb/ser-base.c:444 #6 0x000055fc7eda718a in ser_base_readchar (scb=0x6250002e4100, timeout=-1) at /home/simark/src/binutils-gdb/gdb/ser-base.c:471 #7 0x000055fc7edb1ecd in serial_readchar (scb=0x6250002e4100, timeout=-1) at /home/simark/src/binutils-gdb/gdb/serial.c:393 #8 0x000055fc7ec48b8f in remote_target::readchar (this=0x617000038780, timeout=-1) at /home/simark/src/binutils-gdb/gdb/remote.c:9446 #9 0x000055fc7ec4da82 in remote_target::getpkt_or_notif_sane_1 (this=0x617000038780, buf=0x6170000387a8, forever=1, expecting_notif=1, is_notif=0x7ffdb77c24f0) at /home/simark/src/binutils-gdb/gdb/remote.c:9928 #10 0x000055fc7ec4f045 in remote_target::getpkt_or_notif_sane (this=0x617000038780, buf=0x6170000387a8, forever=1, is_notif=0x7ffdb77c24f0) at /home/simark/src/binutils-gdb/gdb/remote.c:10037 #11 0x000055fc7ec354d4 in remote_target::wait_ns (this=0x617000038780, ptid=..., status=0x7ffdb77c33c8, options=...) at /home/simark/src/binutils-gdb/gdb/remote.c:8147 #12 0x000055fc7ec38aa1 in remote_target::wait (this=0x617000038780, ptid=..., status=0x7ffdb77c33c8, options=...) at /home/simark/src/binutils-gdb/gdb/remote.c:8337 #13 0x000055fc7f1409ce in target_wait (ptid=..., status=0x7ffdb77c33c8, options=...) at /home/simark/src/binutils-gdb/gdb/target.c:2612 #14 0x000055fc7e19da98 in do_target_wait_1 (inf=0x617000038080, ptid=..., status=0x7ffdb77c33c8, options=...) at /home/simark/src/binutils-gdb/gdb/infrun.c:3636 #15 0x000055fc7e19e26b in operator() (__closure=0x7ffdb77c2f90, inf=0x617000038080) at /home/simark/src/binutils-gdb/gdb/infrun.c:3697 #16 0x000055fc7e19f0c4 in do_target_wait (ecs=0x7ffdb77c33a0, options=...) at /home/simark/src/binutils-gdb/gdb/infrun.c:3716 #17 0x000055fc7e1a31f7 in fetch_inferior_event () at /home/simark/src/binutils-gdb/gdb/infrun.c:4061 Before the aforementioned commit, we would not have cleared TARGET_WNOHANG, the remote target's wait would have returned nothing, and we would have consumed the native target's event. After applying this revert, the testsuite state looks as good as before for me on Ubuntu 20.04 amd64. Change-Id: Ic17a1642935cabcc16c25cb6899d52e12c2f5c3f
2022-02-24gdb: use a range based for loop when iterating over an arrayAndrew Burgess1-6/+2
Make use of a range based for loop to iterate over a static global array, removing the need to have a null entry at the end of the array. There should be no user visible changes after this commit.
2022-02-24gdb/darwin: skip over WIFSTOPPED wait4 statusDominique Quatravaux1-6/+25
On modern Darwin's, there appears to be a new circumstance in which a MACH_NOTIFY_DEAD_NAME message can be received, and which was not previously accounted for: to signal the WIFSTOPPED condition in the debuggee. In that case the debuggee is not dead yet (and in fact, counting it as dead would cause a zombie leak - A process in such a state reparents to PID 1, but cannot be killed). - Read and ignore such messages (counting on the next exception message to let us know of the inferior's new state again) - Refactor logging so as to clearly distinguish between the MACH_NOTIFY_DEAD_NAME cases (WIFEXITED, WIFSTOPPED, signal, or something else), and warn in the last case Co-authored-by: Louis-He <1726110778@qq.com> Co-authored-by: Philippe Blain <levraiphilippeblain@gmail.com> Change-Id: Ie86904a894e9bd154e6b674b1bfbfbaee7fde3e1
2022-02-24gdb/linux-tdep: move "Perms" column rightSimon Marchi1-10/+12
Commit 29ef4c0699e1 ("gdb/linux-tdep.c: Add Perms to the 'info proc mappings' output") has broken test gdb.base/info-proc.exp on Linux, because it changes the output of "info proc mappings" in a way that the test does not expect (my bad for not testing before pushing). I looked at how FreeBSD handles this, since I remembered it did show permission flags. It looks like this: Start Addr End Addr Size Offset Flags File 0x200000 0x243000 0x43000 0x0 r-- CN-- /usr/local/bin/tmux (I think that `Flags` and the flags not being aligned is not intentional) The test passes on FreeBSD, because the test looks for four hex numbers in a row and ignores the rest: ".*Mapped address spaces:.*${hex}${ws}${hex}${ws}${hex}${ws}${hex}.*" I suggest fixing it on Linux by moving the flags column to the same place as in the FreeBSD output. It makes things a bit more consistent between OSes, and we don't have to touch the test. At the same time, make use of the actual length of the permission's string to specify the number of characters to print. Before this patch, the output looks like: Start Addr End Addr Perms Size Offset objfile 0x55dd4b544000 0x55dd4b546000 r--p 0x2000 0x0 /usr/bin/sleep and after, it looks like: Start Addr End Addr Size Offset Perms objfile 0x5622ae662000 0x5622ae664000 0x2000 0x0 r--p /usr/bin/sleep Change-Id: If0fc167b010b25f97a3c54e2f491df4973ccde8f
2022-02-24gdb/linux-tdep: make read_mapping return a structureSimon Marchi1-52/+57
Change read_mapping to return a structure instead of taking many output parameters. Change the string + length output parameters (permissions and device) to be gdb::string_view, since that's what string_view is for (a non-NULL terminated view on a string). No changes in behavior expected. Change-Id: I86e627d84d3dda8c9b835592b0f4de8d90d12112
2022-02-23Fix bug in C++ overload resolutionTom Tromey3-9/+47
PR c++/28901 points out a bug in C++ overload resolution. When comparing two overloads, one might be better than the other for certain parameters -- but, if that one also has some invalid conversion, then it should never be considered the better choice. Instead, a valid-but-not-apparently-quite-as-good overload should be preferred. This patch fixes this problem by changing how overload comparisons are done. I don't believe it should affect any currently valid overload resolution; nor should it affect resolutions where all the choices are equally invalid.
2022-02-23gdb/linux-tdep.c: Add Perms to the 'info proc mappings' outputDominik 'Disconnect3d' Czarnota1-8/+8
Fixes #28914 and so it adds a 'Perms' (permissions) column to the 'info proc mappings' command output. This will allow users to know the memory pages permissions right away from GDB instead of having to fetch them from the /proc/$pid/maps file (which is also what GDB does internally, but it just did not print that column). Below I am also showing how an example output looks like before and after this commit in case someone wonders. On i386 targets - before this commit: ``` (gdb) info proc mappings process 3461464 Mapped address spaces: Start Addr End Addr Size Offset objfile 0x56555000 0x56556000 0x1000 0x0 /home/dc/src/binutils-gdb/build/a.out 0x56556000 0x56557000 0x1000 0x1000 /home/dc/src/binutils-gdb/build/a.out 0x56557000 0x56558000 0x1000 0x2000 /home/dc/src/binutils-gdb/build/a.out 0x56558000 0x5655a000 0x2000 0x2000 /home/dc/src/binutils-gdb/build/a.out 0xf7fc4000 0xf7fc8000 0x4000 0x0 [vvar] 0xf7fc8000 0xf7fca000 0x2000 0x0 [vdso] 0xf7fca000 0xf7fcb000 0x1000 0x0 /usr/lib/i386-linux-gnu/ld-2.33.so 0xf7fcb000 0xf7fee000 0x23000 0x1000 /usr/lib/i386-linux-gnu/ld-2.33.so 0xf7fee000 0xf7ffb000 0xd000 0x24000 /usr/lib/i386-linux-gnu/ld-2.33.so 0xf7ffb000 0xf7ffe000 0x3000 0x30000 /usr/lib/i386-linux-gnu/ld-2.33.so 0xfffdc000 0xffffe000 0x22000 0x0 [stack] (gdb) ``` On i386 targets - after this commit: ``` (gdb) info proc mappings process 3461464 Mapped address spaces: Start Addr End Addr Perms Size Offset objfile 0x56555000 0x56556000 r--p 0x1000 0x0 /home/dc/src/binutils-gdb/build/a.out 0x56556000 0x56557000 r-xp 0x1000 0x1000 /home/dc/src/binutils-gdb/build/a.out 0x56557000 0x56558000 r--p 0x1000 0x2000 /home/dc/src/binutils-gdb/build/a.out 0x56558000 0x5655a000 rw-p 0x2000 0x2000 /home/dc/src/binutils-gdb/build/a.out 0xf7fc4000 0xf7fc8000 r--p 0x4000 0x0 [vvar] 0xf7fc8000 0xf7fca000 r-xp 0x2000 0x0 [vdso] 0xf7fca000 0xf7fcb000 r--p 0x1000 0x0 /usr/lib/i386-linux-gnu/ld-2.33.so 0xf7fcb000 0xf7fee000 r-xp 0x23000 0x1000 /usr/lib/i386-linux-gnu/ld-2.33.so 0xf7fee000 0xf7ffb000 r--p 0xd000 0x24000 /usr/lib/i386-linux-gnu/ld-2.33.so 0xf7ffb000 0xf7ffe000 rw-p 0x3000 0x30000 /usr/lib/i386-linux-gnu/ld-2.33.so 0xfffdc000 0xffffe000 rw-p 0x22000 0x0 [stack] (gdb) ``` On amd64 targets - after this commit: ``` (gdb) info proc mappings process 3461869 Mapped address spaces: Start Addr End Addr Perms Size Offset objfile 0x555555554000 0x555555555000 r--p 0x1000 0x0 /home/dc/src/binutils-gdb/build/a.out 0x555555555000 0x555555556000 r-xp 0x1000 0x1000 /home/dc/src/binutils-gdb/build/a.out 0x555555556000 0x555555557000 r--p 0x1000 0x2000 /home/dc/src/binutils-gdb/build/a.out 0x555555557000 0x555555559000 rw-p 0x2000 0x2000 /home/dc/src/binutils-gdb/build/a.out 0x7ffff7fc3000 0x7ffff7fc7000 r--p 0x4000 0x0 [vvar] 0x7ffff7fc7000 0x7ffff7fc9000 r-xp 0x2000 0x0 [vdso] 0x7ffff7fc9000 0x7ffff7fca000 r--p 0x1000 0x0 /usr/lib/x86_64-linux-gnu/ld-2.33.so 0x7ffff7fca000 0x7ffff7ff1000 r-xp 0x27000 0x1000 /usr/lib/x86_64-linux-gnu/ld-2.33.so 0x7ffff7ff1000 0x7ffff7ffb000 r--p 0xa000 0x28000 /usr/lib/x86_64-linux-gnu/ld-2.33.so 0x7ffff7ffb000 0x7ffff7fff000 rw-p 0x4000 0x31000 /usr/lib/x86_64-linux-gnu/ld-2.33.so 0x7ffffffdd000 0x7ffffffff000 rw-p 0x22000 0x0 [stack] 0xffffffffff600000 0xffffffffff601000 --xp 0x1000 0x0 [vsyscall] (gdb) ``` Signed-off-by: Dominik 'Disconnect3d' Czarnota <dominik.b.czarnota@gmail.com> Change-Id: I4991f6cc758cd532eae3ae98c29d22e7bd9d9c36
2022-02-22NEWS: Note that the FreeBSD async target supports async mode.John Baldwin1-0/+2
2022-02-22inf-ptrace: Add an event_pipe to be used for async mode in subclasses.John Baldwin6-148/+78
Subclasses of inf_ptrace_target have to opt-in to using the event_pipe by implementing the can_async_p and async methods. For subclasses which do this, inf_ptrace_target provides is_async_p, async_wait_fd and closes the pipe in the close target method. inf_ptrace_target also provides wrapper routines around the event pipe (async_file_open, async_file_close, async_file_flush, and async_file_mark) for use in target methods such as async. inf_ptrace_target also exports a static async_file_mark_if_open function which can be used in SIGCHLD signal handlers.
2022-02-22Enable async mode in the target in attach_cmd.John Baldwin5-22/+4
If the attach target supports async mode, enable it after the attach target's ::attach method returns.
2022-02-22fbsd-nat: Return nullptr rather than failing ::thread_name.John Baldwin1-2/+2
ptrace on FreeBSD cannot be used against running processes and instead fails with EBUSY. This meant that 'info threads' would fail if any of the threads were running (for example when using schedule-multiple=on in gdb.base/fork-running-state.exp). Instead of throwing errors, just return nullptr as no thread name is better than causing info threads to fail completely.
2022-02-22fbsd-nat: Various cleanups to the ::resume entry debug message.John Baldwin1-2/+3
Move the message from 'show debug fbsd-lwp' to 'show debug fbsd-nat' since it is helpful for debugging async target support and not just LWP support. Use target_pid_to_str to format the ptid and log the step and signo arguments.
2022-02-22fbsd-nat: Include ptrace operation in error messages.John Baldwin1-16/+18
2022-02-22fbsd-nat: Implement async target support.John Baldwin2-2/+164
This is a fairly simple version of async target support. Synchronous mode still uses blocking waitpid() calls in inf_ptrace::wait() unlike the Linux native target which always uses WNOHANG and uses sigsuspend() for synchronous operation. Asynchronous mode registers an event pipe with the core as a file handle and writes to the pipe when SIGCHLD is raised. TARGET_WNOHANG is handled by inf_ptrace::wait().
2022-02-22inf-ptrace: Support async targets in inf_ptrace_target::wait.John Baldwin1-3/+24
- Handle TARGET_WNOHANG by passing WNOHANG to waitpid and returning TARGET_WAITKIND_IGNORE if there are no events to report. - Handle a race in async mode where SIGCHLD might signal the event pipe for an event that has already been reported. If the event was the exit of the last child process, waitpid() will fail with ECHILD rather than returning a pid of 0. For this case, return TARGET_WAITKIND_NO_RESUMED.
2022-02-22inf-ptrace: Return an IGNORE event if waitpid() fails.John Baldwin1-3/+2
Previously this returned a TARGET_WAITKIND_SIGNALLED event for inferior_ptid. However, inferior_ptid is invalid during ::wait() methods after the multi-target changes, so this was triggering an assertion further up the stack.
2022-02-22do_target_wait_1: Clear TARGET_WNOHANG if the target isn't async.John Baldwin1-1/+1
Previously, TARGET_WNOHANG was cleared if a target supported async mode even if async mode wasn't currently enabled. This change only permits TARGET_WNOHANG if async mode is enabled.
2022-02-22Don't enable async mode at the end of target ::resume methods.John Baldwin3-23/+0
Now that target_resume always enables async mode after target::resume returns, these calls are redundant. The other place that target resume methods are invoked outside of target_resume are as the beneath target in record_full_wait_1. In this case, async mode should already be enabled when supported by the target before the resume method is invoked due to the following: In general, targets which support async mode run as async until ::wait returns TARGET_WAITKIND_NO_RESUMED to indicate that there are no unwaited for children (either they have exited or are stopped). When that occurs, the loop in wait_one disables async mode. Later if a stopped child is resumed, async mode is re-enabled in do_target_resume before waiting for the next event. In the case of record_full_wait_1, this function is invoked from the ::wait target method when fetching an event. If the underlying target supports async mode, then an earlier call to do_target_resume to resume the child reporting an event in the loop in record_full_wait_1 would have already enabled async mode before ::wait was invoked. In addition, nothing in the code executed in the loop in record_full_wait_1 disables async mode. Async mode is only disabled higher in the call stack in wait_one after ::wait returns. It is also true that async mode can be disabled by an INF_EXEC_COMPLETE event passed to inferior_event_handle, but all of the places that invoke that are in the gdb core which is "above" a target ::wait method. Note that there is an earlier call to enable async mode in linux_nat_target::resume. That call also marks the async event pipe to report an existing event after enabling async mode, so it needs to stay.
2022-02-22Enable async mode on supported targets in target_resume.John Baldwin2-3/+3
Enabling async mode above the target layer removes duplicate code in ::resume methods of async-capable targets. Commit 5b6d1e4fa4f ("Multi-target support") enabled async mode in do_target_resume after target_resume returns which is a step in this direction. However, other callers of target_resume such as target_continue do not enable async mode. Rather than enabling async mode in each of the callers after target_resume returns, enable async mode at the end of target_resume.
2022-02-22gdb linux-nat: Convert linux_nat_event_pipe to the event_pipe class.John Baldwin1-43/+16
Use event_pipe from gdbsupport in place of the existing file descriptor array.
2022-02-22gdb: fix detection of compilation and linking flags for source-highlightRuslan Kabatsayev2-12/+12
Currently there are two problems with the detection of source-highlight via pkg-config in GDB's configure script: 1. The LDFLAGS variable is used to pass the 'pkg-config --libs' output to AC_LINK_IFELSE, which results in the "-L/some/path -lsource-highlight" preceding the conftest.cpp, which can result in a failure to find symbols referenced in conftest.cpp, if the linker is using --as-needed by default. 2. The CFLAGS variable is used to pass the 'pkg-config --cflags' output to AC_LINK_IFELSE. However, as the current language is C++, AC_LINK_IFELSE will actuall use CXXFLAGS, not CFLAGS, so any flags returned from pkg-config will not be seen. This patch fixes both of these mistakes, allowing GDB to correctly configure and build using source-highlight installed into a custom prefix, e.g. ~/opt/gdb-git (because the system version of source-highlight is too old).
2022-02-22gdb/testsuite/README: point to default value of INTERNAL_GDBFLAGSPhilippe Blain2-7/+9
The INTERNAL_GDBFLAGS runtest variable was updated in 55c3ad88013 ([gdb/testsuite] Prevent pagination in GDB_INTERNALFLAGS, 2020-10-26) to disable pagination, and in aae1c79a03a (PR python/12227..., 2010-12-07) to point to the data directory, but its default value mentioned in the testsuite's README was not kept up to date. To avoid it getting out of sync even more, point the reader to the definition of the variable in lib/gdb.exp, and move the explanation of the different flags there. Also adjust the example in the README so it follows the flags added in 55c3ad88013. Change-Id: I3533608a7d6ae5198af09c7dc7743bde24c19ed7
2022-02-21gdb/testsuite: relax pattern in new gdb.mi/mi-multi-commands.exp testAndrew Burgess1-4/+4
I saw some failures in the test gdb.mi/mi-multi-commands.exp that I added recently. This test was added in commit: commit d08cbc5d3203118da5583296e49273cf82378042 Date: Wed Dec 22 12:57:44 2021 +0000 gdb: unbuffer all input streams when not using readline The failures I see only occurred when my machine was very heavily loaded. In this test I send multiple commands from dejagnu to gdb with a single send_gdb call. In a well behaving world what I want to happen is that the gdb console sees both commands arrive and echos the text of those commands. Then gdb starts processing the first command, prints the result, and then processes the second command, and prints the result. However, what I saw in my loaded environment was that only after sending the two commands, only the first command was echoed to gdb's terminal. Then gdb started processing the first command, and started to write the output. Now, mixed in with the first command output, the second command was echoed to gdb's terminal. Finally, gdb would finish printing the first command output, and would read and handle the second command. This mixing of command echoing with the first command output was causing the test matching patterns to fail. In this commit I change the command I use in the test from a CLI command to an MI command, this reduces the number of lines of output that come from the test, CLI commands sent through the MI interpreter are echoed back like this: (gdb) set $a = "FIRST COMMAND" &"set $a = \"FIRST COMMAND\"\n" ^done (gdb) While this is not the case for true MI command: (gdb) -data-evaluate-expression $a ^done,value="\"FIRST COMMAND\"" (gdb) Less output makes for simpler patterns to match against. Next, when sending two command to gdb I was previously trying to spot the output of the first command followed by the prompt with nothing between. This is not really needed, for the first command I can look for just the ^done,value="\"FIRST COMMAND\"" string, then I can start looking for the output of the second command. So long as the second pattern matches up to the gdb prompt, then I can be sure than nothing is left over in the expect buffer to muck up later matches. As to see the second command output gdb must have read in the second command, the second command output never suffers from the corruption that the first command output does. Since making this change, I've not seen a failure in this test.
2022-02-21gdb: avoid nullptr access in dbxread.c from read_dbx_symtabAndrew Burgess1-49/+88
This fixes a GDB crash reported in bug pr/28900, related to reading in some stabs debug information. In this commit my goal is to stop GDB crashing. I am not trying to ensure that GDB makes the best possible use of the available stabs debug information. At this point I consider stabs a legacy debug format, with only limited support in GDB. So, the problem appears to be that, when reading in the stabs data, we need to find a N_SO entry, this is the entry that defines the start of a compilation unit (or at least the location of a corresponding source file). It is while handling an N_SO that GDB creates a psymtab to hold the incoming debug information (symbols, etc). The problem we hit in the bug is that we encounter some symbol information (an N_PC entry) outside of an N_SO entry - that is we find some symbol information that is not associated with any source file. We already have some protection for this case, look (in read_dbx_symtab) at the handling of N_PC entries of type 'F' and 'f', if we have no psymtab (the pst variable is nullptr) then we issue a complaint. However, for whatever reason, in both 'f' and 'F' handling, there is one place where we assume that the pst variable (the psymtab) is not nullptr. This is a mistake. In this commit, I guard these two locations (in 'f' and 'F' handling) so we no longer assume pst is not nullptr. While I was at it, I audited all the other uses of pst in read_dbx_symtab, and in every potentially dangerous case I added a nullptr check, and issue a suitable complaint if pst is found to be nullptr. It might well be true that we could/should do something smarter if we see a debug symbol outside of an N_SO entry, and if anyone wanted to do that work, they're welcome too. But this commit is just about preventing the nullptr access, and the subsequent GDB crash. I don't have any tests for this change, I have no idea how to generate weird stabs data for testing. The original binary from the bug report now loads just fine without GDB crashing. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28900
2022-02-21gdb: make use of std::string in dbxread.c and xcoffread.cAndrew Burgess2-28/+8
While taking a look through dbxread.c I spotted a couple of places where making use of std::string would remove the need for manual memory allocation and memcpy. During review Simon pointed out that the same code exists in xcoffread.c, so I've applied the same fix there too. There should be no user visible changes after this commit.
2022-02-20gdb: Only paginate for filtered output in fputs_maybe_filteredLancelot SIX1-1/+2
A have had situation where a unfiltered output (done using fputs_unfiltered) ended up triggering pagination. The backtrace for this was: ... #24 0x000055839377ee4e in check_async_event_handlers () at ../../gdb/async-event.c:335 #25 0x0000558394b67b57 in gdb_do_one_event () at ../../gdbsupport/event-loop.cc:216 #26 0x0000558394587454 in gdb_readline_wrapper (prompt=0x7ffd907712d0 "--Type <RET> for more, q to quit, c to continue without paging--") at ../../gdb/top.c:1148 #27 0x0000558394707270 in prompt_for_continue () at ../../gdb/utils.c:1438 #28 0x00005583947088b3 in fputs_maybe_filtered (linebuffer=0x60c0000f4000 " [...quite big message...]", stream=0x60300028e9d0, filter=0) at ../../gdb/utils.c:1752 #29 0x0000558394708e57 in fputs_unfiltered (linebuffer=0x60c0000f4000 " [...quite big message...]", stream=0x60300028e9d0) at ../../gdb/utils.c:1811 ... This comes from what appears to be a oversight in fputs_maybe_filtered. This function has a FILTER parameter which if true makes the function pause after every screenful (i.e. triggers pagination). The filter parameter is correctly used to guard the first place where prompt_for_continue. There is a second place in the function which can call prompt_for_continue, but is currently unguarded. I believe that this is an oversight, this patch fixes that. Tested on Linux-x86_64, no regression observed. Change-Id: Iad8ffd50a87cf20077500878e2564b5a7dc81ece
2022-02-19gdb/darwin: remove not-so-harmless spurious call to `wait4`Dominique Quatravaux1-3/+0
As seen in https://sourceware.org/bugzilla/show_bug.cgi?id=24069 this code will typically wait4() a second time on the same process that was already wait4()'d a few lines above. While this used to be harmless/idempotent (when we assumed that the process already exited), this now causes a deadlock in the WIFSTOPPED case. The early (~2019) history of bug #24069 cautiously suggests to use WNOHANG instead of outright deleting the call. However, tests on the current version of Darwin (Big Sur) demonstrate that gdb runs just fine without a redundant call to wait4(), as would be expected. Notwithstanding the debatable value of conserving bug compatibility with an OS release that is more than a decade old, there is scant evidence of what that double-wait4() was supposed to achieve in the first place - A cursory investigation with `git blame` pinpoints commits bb00b29d7802 and a80b95ba67e2 from the 2008-2009 era, but fails to answer the "why" question conclusively. Co-Authored-By: Philippe Blain <levraiphilippeblain@gmail.com> Change-Id: Id4e4415d66d6ff6b3552b60d761693f17015e4a0
2022-02-18Add constructor to bound_minimal_symbolTom Tromey6-13/+20
This adds a constructor to bound_minimal_symbol, to avoid a build failure with clang that Simon pointed out. I also took the opportunity to remove some redundant initializations, and to change one use of push_back to emplace_back, as suggested by Simon.
2022-02-18gdb: remove newlines from some linux_nat_debug_printf callsSimon Marchi1-3/+3
Change-Id: I80328fab7096221356864b5a4fb30858b48d2c10
2022-02-16gdb/tui: add a missing white space characterAndrew Burgess1-1/+1
Just adds a missing space. There should be no user visible changes after this commit.
2022-02-16gdb: convert callback_handler_installed from int to boolAndrew Burgess1-3/+3
Simple int to bool conversion on callback_handler_installed in event-top.c. There should be no user visible changes after this commit.
2022-02-15gdb: Respect the DW_CC_nocall attributeLancelot SIX7-3/+182
It is possible for a compiler to optimize a function in a such ways that the function does not follow the calling convention of the target. In such situation, the compiler can use the DW_AT_calling_convention attribute with the value DW_CC_nocall to tell the debugger that it is unsafe to call the function. The DWARF5 standard states, in 3.3.1.1: > If the value of the calling convention attribute is the constant > DW_CC_nocall, the subroutine does not obey standard calling > conventions, and it may not be safe for the debugger to call this > subroutine. Non standard calling convention can affect GDB's assumptions in multiple ways, including how arguments are passed to the function, how values are returned, and so on. For this reason, it is unsafe for GDB to try to do the following operations on a function with marked with DW_CC_nocall: - call / print an expression requiring the function to be evaluated, - inspect the value a function returns using the 'finish' command, - force the value returned by a function using the 'return' command. This patch ensures that if a command which relies on GDB's knowledge of the target's calling convention is used on a function marked nocall, GDB prints an appropriate message to the user and does not proceed with the operation which is unreliable. Note that it is still possible for someone to use a vendor specific value for the DW_AT_calling_convention attribute for example to indicate the use of an alternative calling convention. This commit does not prevent this, and target dependent code can be adjusted if one wanted to support multiple calling conventions. Tested on x86_64-Linux, with no regression observed. Change-Id: I72970dae68234cb83edbc0cf71aa3d6002a4a540
2022-02-15gdb: add a symbol* argument to get_return_valueLancelot SIX3-34/+44
Add an argument to the get_return_value function to indicate the symbol of the function the debuggee is returning from. This will be used by the following patch. Since the function return type can be deduced from the symbol remove the value_type argument which becomes redundant. No user visible change after this patch. Tested on x86_64-linux. Change-Id: Idf1279f1f7199f5022738a6679e0fa63fbd22edc Co-authored-by: Simon Marchi <simon.marchi@polymtl.ca>
2022-02-14Remove LA_PRINT_STRINGTom Tromey4-18/+8
This removes the LA_PRINT_STRING macro, in favor of using ordinary method calls.
2022-02-14Remove LA_PRINT_CHARTom Tromey5-6/+5
This removes the LA_PRINT_CHAR macro, in favor of using ordinary method calls.
2022-02-14Remove LA_PRINT_TYPETom Tromey5-17/+17
This removes the LA_PRINT_TYPE macro, in favor of using ordinary method calls.