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2021-08-30gdb: fix build error in unittests/parallel-for-selftests.cSimon Marchi1-1/+1
We get this error when building GDB on some platforms. I get it using g++-10 on Ubuntu 20.04 (installed using the distro package). It was also reported by John Baldwin, using a clang that uses libc++. CXX unittests/parallel-for-selftests.o cc1plus: warning: command line option '-Wmissing-prototypes' is valid for C/ObjC but not for C++ /home/smarchi/src/binutils-gdb/gdb/unittests/parallel-for-selftests.c: In function 'void selftests::parallel_for::test(int)': /home/smarchi/src/binutils-gdb/gdb/unittests/parallel-for-selftests.c:53:30: error: use of deleted function 'std::atomic<int>::atomic(const std::atomic<int>&)' 53 | std::atomic<int> counter = 0; | ^ In file included from /usr/include/c++/9/future:42, from /home/smarchi/src/binutils-gdb/gdb/../gdbsupport/thread-pool.h:29, from /home/smarchi/src/binutils-gdb/gdb/../gdbsupport/parallel-for.h:26, from /home/smarchi/src/binutils-gdb/gdb/unittests/parallel-for-selftests.c:22: /usr/include/c++/9/atomic:755:7: note: declared here 755 | atomic(const atomic&) = delete; | ^~~~~~ /usr/include/c++/9/atomic:759:17: note: after user-defined conversion: 'constexpr std::atomic<int>::atomic(std::atomic<int>::__integral_type)' 759 | constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { } | ^~~~~~ I haven't dug to know why it does not happen everywhere, but this patch fixes it by using the constructor to initialize the variable, rather than the assignment operator. Change-Id: I6b27958171bf6187f6a875657395fd10441db7e6
2021-08-30Add some parallel_for_each testsTom Tromey2-0/+87
Tom de Vries noticed that a patch in the DWARF scanner rewrite series caused a regression in parallel_for_each -- it started crashing in the case where the number of threads is 0 (there was an unchecked use of "n-1" that was used to size an array). He also pointed out that there were no tests of parallel_for_each. This adds a few tests of parallel_for_each, primarily testing that different settings for the number of threads will work. This test catches the bug that he found in that series.
2021-08-30Add a show function for "maint show worker-threads"Tom Tromey1-1/+17
I wanted to see how many threads gdb thought it was using, but "maint show worker-threads" only reported "unlimited". This patch adds a show function so that it will now report the number of threads gdb has started. Regression tested on x86-64 Fedora 34.
2021-08-30[gdb/cli] Don't assert on empty string for core-fileTom de Vries2-1/+6
With current gdb we run into: ... $ gdb -batch '' '' : No such file or directory. pathstuff.cc:132: internal-error: \ gdb::unique_xmalloc_ptr<char> gdb_abspath(const char*): \ Assertion `path != NULL && path[0] != '\0'' failed. ... Fix this by skipping the call to gdb_abspath in core_target_open in the empty-string case, such that we have instead: ... $ gdb -batch '' '' : No such file or directory. : No such file or directory. $ ... Tested on x86_64-linux. gdb/ChangeLog: 2021-08-30 Tom de Vries <tdevries@suse.de> PR cli/28290 * gdb/corelow.c (core_target_open): Skip call to gdb_abspath in the empty-string case. gdb/testsuite/ChangeLog: 2021-08-30 Tom de Vries <tdevries@suse.de> PR cli/28290 * gdb.base/batch-exit-status.exp: Add gdb '' and gdb '' '' tests.
2021-08-30[gdb/testsuite] Improve argument syntax of proc arangeTom de Vries7-56/+150
The current syntax of proc arange is: ... proc arange { arange_start arange_length {comment ""} {seg_sel ""} } { ... and a typical call looks like: ... arange $start $len ... This style is somewhat annoying because if you want to specify the last parameter, you need to give the default values of all the other optional ones before as well: ... arange $start $len "" $seg_sel ... Update the syntax to: ... proc arange { options arange_start arange_length } { parse_options { { comment "" } { seg_sel "" } } ... such that a typical call looks like: ... arange {} $start $len ... and a call using seg_sel looks like: ... arange { seg_sel $seg_sel } $start $len ... Also update proc aranges, which already has an options argument, to use the new proc parse_options. Tested on x86_64-linux. Co-Authored-By: Simon Marchi <simon.marchi@polymtl.ca>
2021-08-27[gdb/symtab] Don't write .gdb_index symbol table with empty entriesTom de Vries1-0/+3
When comparing the sizes of the index files generated for shlib outputs/gdb.dwarf2/dw2-zero-range/shr1.sl, I noticed a large difference between .debug_names: ... $ gdb -q -batch $shlib -ex "save gdb-index -dwarf-5 ." $ du -b -h shr1.sl.debug_names shr1.sl.debug_str 61 shr1.sl.debug_names 0 shr1.sl.debug_str ... and .gdb_index: ... $ gdb -q -batch $shlib -ex "save gdb-index ." $ du -b -h shr1.sl.gdb-index 8.2K shr1.sl.gdb-index ... The problem is that the .gdb_index contains a non-empty symbol table with only empty entries. Fix this by making the symbol table empty, such that we have instead: ... $ du -b -h shr1.sl.gdb-index 184 shr1.sl.gdb-index ... Tested on x86_64-linux.
2021-08-27[gdb/testsuite] Generate .debug_aranges in gdb.dlang/watch-loc.expTom de Vries2-41/+8
Before commit 5ef670d81fd "[gdb/testsuite] Add dummy start and end CUs in dwarf assembly" we had in exec outputs/gdb.dlang/watch-loc/watch-loc a D compilation unit at offset 0xc7: ... Compilation Unit @ offset 0xc7: Length: 0x4c (32-bit) Version: 4 Abbrev Offset: 0x64 Pointer Size: 8 <0><d2>: Abbrev Number: 2 (DW_TAG_compile_unit) <d3> DW_AT_language : 19 (D) ... with a corresponding .debug_aranges entry: ... Offset into .debug_info: 0xc7 Pointer Size: 4 Segment Size: 0 Address Length 004004a7 0000000b 00000000 00000000 ... After that commit we have a dummy CU at offset 0xc7 and the D compilation unit at offset 0xd2: ... Compilation Unit @ offset 0xc7: Length: 0x7 (32-bit) Version: 4 Abbrev Offset: 0x64 Pointer Size: 8 Compilation Unit @ offset 0xd2: Length: 0x4c (32-bit) Version: 4 Abbrev Offset: 0x65 Pointer Size: 8 <0><dd>: Abbrev Number: 2 (DW_TAG_compile_unit) <de> DW_AT_language : 19 (D) ... while the .debug_aranges entry still points to 0xc7. The problem is that the test-case uses a hack (quoting from commit 75f06e9dc59): ... [ Note: this is a non-trivial test-case. The file watch-loc-dw.S contains a .debug_info section, but not an .debug_aranges section or any actual code. The file watch-loc.c contains code and a .debug_aranges section, but no other debug section. So, the intent for the .debug_aranges section in watch-loc.c is to refer to a compilation unit in the .debug_info section in watch-loc-dw.S. ] ... and adding the dummy CU caused that hack to stop working. Fix this by moving the generation of .debug_aranges from watch-loc.c to watch-loc.exp, such that we have: ... Offset into .debug_info: 0xd2 Pointer Size: 4 Segment Size: 0 Address Length 004004a7 0000000b 00000000 00000000 ... Tested on x86_64-linux.
2021-08-27[gdb/testsuite] Generate .debug_aranges entry for dummy CUTom de Vries1-1/+5
A best practise for DWARF [1] is to generate .debug_aranges entries for CUs even if they have no address range. Generate .debug_arange entries for the dummy CUs added by the DWARF assembler. Tested on x86_64-linux. [1] http://wiki.dwarfstd.org/index.php?title=Best_Practices
2021-08-27[gdb/testsuite] Add .debug_aranges in more test-casesTom de Vries3-3/+22
A couple of test-cases fail when run with target board cc-with-debug-names due to missing .debug_aranges entries for the CUs added by the dwarf assembler. Add a .debug_aranges entry for those CUs. Tested on x86_64-linux.
2021-08-27[gdb/testsuite] Support .debug_aranges in dwarf assemblyTom de Vries1-0/+153
Add a proc aranges such that we can generate .debug_aranges sections in dwarf assembly using: ... cu { label cu_label } { ... } aranges {} cu_label { arange $addr $len [<comment>] [$segment_selector] } ... Tested on x86_64-linux.
2021-08-27[gdb/testsuite] Add label option to proc cuTom de Vries1-0/+11
We can use current dwarf assembly infrastructure to declare a label that marks the start of the CU header: ... declare_labels header_start_cu_a _section ".debug_info" header_start_cu_a : cu {} { } _section ".debug_info" header_start_cu_b : cu {} { } ... on the condition that we switch to the .debug_info section before, which makes this style of use fragile. Another way to achieve the same is to use the label as generated by the cu proc itself: ... variable _cu_label cu {} { } set header_start_cu_a $_cu_label cu {} { } set header_start_cu_b $_cu_label ... but again that seems fragile given that adding a new CU inbetween will silently result in the wrong value for the label. Add a label option to proc cu such that we can simply do: ... cu { label header_start_cu_a } { } cu { label header_start_cu_b } { } ... Tested on x86_64-linux.
2021-08-26gdb: remove some stray newlines in debug outputAndrew Burgess1-2/+2
I spotted a couple of stray newlines that were left at the end of debug message during conversion to the new debug output scheme. These messages are part of the 'set debug lin-lwp 1' output.
2021-08-24Fix two regressions caused by CU / TU mergingTom Tromey2-39/+85
PR symtab/28160 and PR symtab/27893 concern GDB crashes in the test suite when using the "fission" target board. They are both caused by the patches that merge the list of CUs with the list of TUs (and to a lesser degree by the patches to share DWARF data across objfiles), and the underlying issue is the same: it turns out that reading a DWO can cause new type units to be created. This means that the list of dwarf2_per_cu_data objects depends on precisely which CUs have been expanded. However, because the type units can be created while expanding a CU means that the vector of CUs can expand while it is being iterated over -- a classic mistake. Also, because a TU can be added later, it means the resize_symtabs approach is incorrect. This patch fixes resize_symtabs by removing it, and having set_symtab resize the vector on demand. It fixes the iteration problem by introducing a safe (index-based) iterator and changing the relevant spots to use it. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28160 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=27893
2021-08-23Fix a latent bug in dw2-ranges-overlap.expTom Tromey2-6/+13
dw2-ranges-overlap.exp creates a program where a psymtab has two address ranges, and a function without debug info whose address is between these two ranges. Then it sets a breakpoint on this function and runs to it, expecting that the language should remain "auto; c" when stopped. However, this test case also has a "main" function described (briefly) in the DWARF, and this function is given language C++. Also, a breakpoint stop sets the current language to the language that was used when setting the breakpoint. My new DWARF scanner decides that this "main" is the main program and sets the current language to C++ at startup, causing this test to fail. This patch fixes the test in a simple way, by introducing a new function that takes the place of "main" in the DWARF. I think this still exercises the original problem, but also avoids problems with my branch. It seemed safe to me to submit this separately.
2021-08-23[gdb] Fix 'not in executable format' error messageTom de Vries2-5/+35
With trying to load a non-executable file into gdb, we run into PR26880: ... $ gdb -q -batch test.c "0x7ffc87bfc8d0s": not in executable format: \ file format not recognized ... The problem is caused by using %ps in combination with the error function (note that confusingly, it does work in combination with the warning function). Fix this by using plain "%s" instead. Tested on x86_64-linux. gdb/ChangeLog: 2021-08-22 Tom de Vries <tdevries@suse.de> PR gdb/26880 * gdb/exec.c (exec_file_attach): Use %s instead of %ps in call to error function. gdb/testsuite/ChangeLog: 2021-08-22 Tom de Vries <tdevries@suse.de> PR gdb/26880 * gdb.base/non-executable.exp: New file.
2021-08-23[gdb/testsuite] Use compiler-generated instead of gas-generated stabsTom de Vries1-12/+3
The test-case gdb.dwarf2/dw2-ranges.exp is the only one in the gdb testsuite that uses gas-generated stabs. While the use seems natural alongside the use of gas-generated dwarf in the same test-case, there are a few known issues, filed on the gdb side as: - PR symtab/12497 - "stabs: PIE relocation does not work" - PR symtab/28221 - "[readnow, stabs] FAIL: gdb.dwarf2/dw2-ranges.exp: \ info line func" and on the gas side as: - PR gas/28233 - "[gas, --gstabs] Generate stabs more similar to gcc" The test-case contains a KFAIL for PR12497, but it's outdated and fails to trigger. The intention of the test-case is to test gas-generated dwarf, and using gcc-generated stabs instead of gas-generated stabs works fine. Supporting compiler-generated stabs is already a corner-case for gdb, and there's no current commitment/incentive to support/workaround gas-generated stabs, which can be considered a corner-case of a corner-case. Work around these problem by using compiler-generated stabs in the test-case. Tested on x86_64-linux. gdb/testsuite/ChangeLog: 2021-08-22 Tom de Vries <tdevries@suse.de> * gdb.dwarf2/dw2-ranges.exp: Use compiler-generated stabs.
2021-08-23[gdb/testsuite] Add dummy start and end CUs in dwarf assemblyTom de Vries1-1/+16
Say one compiles a hello.c: ... $ gcc -g hello.c ... On openSUSE Leap 15.2 and Tumbleweed, the CU for hello.c is typically not the first in .debug_info, nor the last, due to presence of debug information in objects for sources like: - ../sysdeps/x86_64/start.S - init.c - ../sysdeps/x86_64/crti.S - elf-init.c - ../sysdeps/x86_64/crtn.S. On other systems, say ubuntu 18.04.5, the CU for hello.c is typically the first and the last in .debug_info. This difference has caused me to find some errors in the dwarf assembly using openSUSE, that didn't show up on other platforms. Force the same situation on other platforms by adding a dummy start and end CU. Tested on x86_64-linux. gdb/testsuite/ChangeLog: 2021-08-22 Tom de Vries <tdevries@suse.de> PR testsuite/28235 * lib/dwarf.exp (Dwarf::dummy_cu): New proc. (Dwarf::assemble): Add dummy start and end CU.
2021-08-23[gdb/testsuite] Fix dw2-ranges-psym.exp with -readnowTom de Vries1-1/+5
When running test-case gdb.dwarf2/dw2-ranges-psym.exp with target board -readnow, I run into: ... (gdb) file dw2-ranges-psym^M Reading symbols from dw2-ranges-psym...^M Expanding full symbols from dw2-ranges-psym...^M (gdb) set complaints 0^M (gdb) FAIL: gdb.dwarf2/dw2-ranges-psym.exp: No complaints ... The problem is that the regexp expects a gdb prompt immediately after the "Reading symbols" line. Fix this by updating the regexp. Tested on x86_64-linux. gdb/testsuite/ChangeLog: 2021-08-22 Tom de Vries <tdevries@suse.de> * lib/gdb.exp (gdb_load_no_complaints): Update regexp to allow "Expanding full symbols" Line.
2021-08-19gdb: use bool in notify_command_param_changed_p and do_set_commandSimon Marchi1-16/+16
Trivial patch to use bool instead of int. Change-Id: I9e5f8ee4305272a6671cbaaaf2f0484eff0d1ea5
2021-08-18gdb/solib: Refactor scan_dyntagAaron Merey4-210/+122
scan_dyntag is unnecessarily duplicated in solib-svr4.c and solib-dsbt.c. Move this function to solib.c and rename it to gdb_bfd_scan_elf_dyntag. Also add it to solib.h so it is included in both solib-svr4 and solib-dsbt.
2021-08-18[gdb] [rs6000] Add ppc64_linux_gcc_target_options method.Will Schmidt1-0/+10
Add a method to set the gcc target options for the ppc64 targets. This change sets an empty value, which allows the gcc default values (-mcmodel=medium) be used, instead of -mcmodel=large which is set by the default_gcc_target_options hook.
2021-08-18[gdb] [rs6000] Add ppc64*_gnu_triplet_regexp methods.Will Schmidt1-0/+29
Add methods to set the target triplet so we can find the proper gcc when our gcc is named of the form powerpc64{le}-<foo>-gcc or ppc64{le}-<foo>-gcc.
2021-08-17gdb: fix spacing on CCLD silent rulesMike Frysinger1-1/+1
2021-08-17gdb: fix thread_step_over_chain_lengthSimon Marchi1-1/+1
If I debug a single-thread program and look at the infrun debug logs, I see: [infrun] start_step_over: stealing global queue of threads to step, length = 2 That makes no sense... turns out there's a buglet in thread_step_over_chain_length, "num" should be initialized to 0. I think this bug is a leftover from an earlier version of the code (not merged upstream) that manually walked the list, where the first item was implicitly counted (hence the 1). Change-Id: I0af03aa93509aed36528be5076894dc156a0b5ce
2021-08-17gdb: Don't assume r_ldsomap when r_version > 1 on LinuxH.J. Lu27-32/+97
The r_ldsomap field is specific to Solaris (part of librtld_db), and should never be accessed for Linux. glibc is planning to add a field to support multiple namespaces. But there will be no r_ldsomap when r_version is bumped to 2. Add linux_[ilp32|lp64]_fetch_link_map_offsets to set r_ldsomap_offset to -1 and use them for Linux targets. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28236
2021-08-16Fix register regression in DWARF evaluatorTom Tromey1-1/+3
On an internal test case, using an arm-elf target, commit ba5bc3e5a92 ("Make DWARF evaluator return a single struct value") causes a regression. (It doesn't happen for any of the other cross targets that I test when importing upstream gdb.) I don't know if there's an upstream gdb test case showing the same problem... I can only really run native tests with dejagnu AFAIK. The failure manifests like this: Breakpoint 1, file_1.export_1 (param_1=<error reading variable: Unable to access DWARF register number 64>, str=...) at [...]/file_1.adb:5 Whereas when it works it looks like: Breakpoint 1, file_1.export_1 (param_1=99.0, str=...) at [...]/file_1.adb:5 The difference is that the new code uses the passed-in gdbarch, whereas the old code used the frame's gdbarch, when handling DWARF_VALUE_REGISTER. This patch restores the use of the frame's arch.
2021-08-16Fix Ada regression due to DWARF expression seriesTom Tromey1-1/+3
Commit 0579205aec4 ("Simplify dwarf_expr_context class interface") caused a regression in the internal AdaCore test suite. I didn't try to reproduce this with the GDB test suite, but the test is identical to gdb.dwarf2/dynarr-ptr.exp. The problem is that this change: case DW_OP_push_object_address: /* Return the address of the object we are currently observing. */ - if (this->data_view.data () == nullptr - && this->obj_address == 0) + if (this->m_addr_info == nullptr) ... slightly changes the logic here. In particular, it's possible for the caller to pass in a non-NULL m_addr_info, but one that looks like: (top) p *this.m_addr_info $15 = { type = 0x29b7a70, valaddr = { m_array = 0x0, m_size = 0 }, addr = 0, next = 0x0 } In this case, an additional check is needed. With the current code, what happens instead is that the computation computes an incorrect address -- but one that does not fail in read_memory, due to the precise memory map of the embedded target in question. This patch restores the old logic.
2021-08-16Notify observer of breakpoint auto-disablingPatrick Monnerat3-1/+65
As breakpoint_modified observer is currently notified upon breakpoint stop before handling auto-disabling when enable count is reached, the observer is never notified of the disabling. The problem affects: - The MI interpreter enabled= value when reporting =breakpoint-modified - A Python event handler for breakpoint_modified using the "enabled" member of its parameter - insight: breakpoint GUI window is not properly updated upon auto-disable This patch moves the observer notification after the auto-disabling code and implements corresponding tests for the MI and Python cases. Fixes https://sourceware.org/bugzilla/show_bug.cgi?id=23336 Change-Id: I0c50df4789334071e5390cb46b3ca0d4a7f83c61
2021-08-12gdb: riscv_scan_prologue: handle LD and LW instructionsLancelot SIX4-0/+182
While working on the testsuite, I ended up noticing that GDB fails to produce a full backtrace from a thread waiting in pthread_join. When selecting the waiting thread and using the 'bt' command, the following result can be observed: (gdb) bt #0 0x0000003ff7fccd20 in __futex_abstimed_wait_common64 () from /lib/riscv64-linux-gnu/libpthread.so.0 #1 0x0000003ff7fc43da in __pthread_clockjoin_ex () from /lib/riscv64-linux-gnu/libpthread.so.0 Backtrace stopped: frame did not save the PC On my platform, I do not have debug symbols for glibc, so I need to rely on prologue analysis in order to unwind stack. Here is what the function prologue looks like: (gdb) disassemble __pthread_clockjoin_ex Dump of assembler code for function __pthread_clockjoin_ex: 0x0000003ff7fc42de <+0>: addi sp,sp,-144 0x0000003ff7fc42e0 <+2>: sd s5,88(sp) 0x0000003ff7fc42e2 <+4>: auipc s5,0xd 0x0000003ff7fc42e6 <+8>: ld s5,-2(s5) # 0x3ff7fd12e0 0x0000003ff7fc42ea <+12>: ld a5,0(s5) 0x0000003ff7fc42ee <+16>: sd ra,136(sp) 0x0000003ff7fc42f0 <+18>: sd s0,128(sp) 0x0000003ff7fc42f2 <+20>: sd s1,120(sp) 0x0000003ff7fc42f4 <+22>: sd s2,112(sp) 0x0000003ff7fc42f6 <+24>: sd s3,104(sp) 0x0000003ff7fc42f8 <+26>: sd s4,96(sp) 0x0000003ff7fc42fa <+28>: sd s6,80(sp) 0x0000003ff7fc42fc <+30>: sd s7,72(sp) 0x0000003ff7fc42fe <+32>: sd s8,64(sp) 0x0000003ff7fc4300 <+34>: sd s9,56(sp) 0x0000003ff7fc4302 <+36>: sd a5,40(sp) As far as prologue analysis is concerned, the most interesting part is done at address 0x0000003ff7fc42ee (<+16>): 'sd ra,136(sp)'. This stores the RA (return address) register on the stack, which is the information we are looking for in order to identify the caller. In the current implementation of the prologue scanner, GDB stops when hitting 0x0000003ff7fc42e6 (<+8>) because it does not know what to do with the 'ld' instruction. GDB thinks it reached the end of the prologue but have not yet reached the important part, which explain GDB's inability to unwind past this point. The section of the prologue starting at <+4> until <+12> is used to load the stack canary[1], which will then be placed on the stack at <+36> at the end of the prologue. In order to have the prologue properly handled, this commit proposes to add support for the ld instruction in the RISC-V prologue scanner. I guess riscv32 would use lw in such situation so this patch also adds support for this instruction. With this patch applied, gdb is now able to unwind past pthread_join: (gdb) bt #0 0x0000003ff7fccd20 in __futex_abstimed_wait_common64 () from /lib/riscv64-linux-gnu/libpthread.so.0 #1 0x0000003ff7fc43da in __pthread_clockjoin_ex () from /lib/riscv64-linux-gnu/libpthread.so.0 #2 0x0000002aaaaaa88e in bar() () #3 0x0000002aaaaaa8c4 in foo() () #4 0x0000002aaaaaa8da in main () I have had a look to see if I could reproduce this easily, but in my simple testcases using '-fstack-protector-all', the canary is loaded after the RA register is saved. I do not have a reliable way of generating a prologue similar to the problematic one so I forged one instead. The testsuite have been run on riscv64 ubuntu 21.01 with no regression observed. [1] https://en.wikipedia.org/wiki/Buffer_overflow_protection#Canaries
2021-08-12Update documentation to mention PygmentsTom Tromey1-4/+10
Philippe Blain pointed out that the gdb documentation does not mention that Pygments may be used for source highlighting. This patch updates the docs to reflect how highlighting is actually done.
2021-08-12gdb: make gdbarch_printable_names return a vectorSimon Marchi5-73/+54
I noticed that gdbarch_selftest::operator() leaked the value returned by gdbarch_printable_names. Make gdbarch_printable_names return an std::vector and update callers. That makes it easier for everyone involved, less manual memory management. Change-Id: Ia8fc028bdb91f787410cca34f10bf3c5a6da1498
2021-08-12Improve forward progress test in python.expCarl Love1-1/+16
The test steps into func2 and than does an up to get back to the previous frame. The test checks that the line number you are at after the up command is greater than the line where the function was called from. The assembly/codegen for the powerpc target includes a NOP after the branch-link. func2 (); /* Break at func2 call site. / 10000694: 59 00 00 48 bl 100006ec 10000698: 00 00 00 60 nop return 0; / Break to end. */ 1000069c: 00 00 20 39 li r9,0 The PC at the instruction following the branch-link is 0x10000698 which GDB.find_pc_line() maps to the same line number as the bl instruction. GDB did move past the branch-link location thus making forward progress. The following proposed fix adds an additional PC check to see if forward progress was made. The line test is changed from greater than to greater than or equal.
2021-08-12gdb:csky rm tdesc_has_registers in csky_register_nameJiangshuai Li1-3/+0
As CSKY arch has not parsed target-description.xml in csky_gdbarch_init, when a remote server, like csky-qemu or gdbserver, send a target-description.xml to gdb, tdesc_has_registers will return ture, but tdesc_register_name (gdbarch, 0) will return NULL, so a cmd "info registers r0" will not work. Function of parsing target-description.xml will be add later for CSKY arch, now it is temporarily removed to allow me to do other supported tests. 2021-07-15 Jiangshuai Li <jiangshuai_li@c-sky.com> * csky-tdep.c : not using tdesc funtions in csky_register_name
2021-08-11Deprecate a.out support for NetBSD targets.John Ericson3-26/+16
As discussed previously, a.out support is now quite deprecated, and in some cases removed, in both Binutils itself and NetBSD, so this legacy default makes little sense. `netbsdelf*` and `netbsdaout*` still work allowing the user to be explicit about there choice. Additionally, the configure script warns about the change as Nick Clifton requested. One possible concern was the status of NetBSD on NS32K, where only a.out was supported. But per [1] NetBSD has removed support, and if it were to come back, it would be with ELF. The binutils implementation is therefore marked obsolete, per the instructions in the last message. With that patch and this one applied, I have confirmed the following: --target=i686-unknown-netbsd --target=i686-unknown-netbsdelf builds completely --target=i686-unknown-netbsdaout properly fails because target is deprecated. --target=vax-unknown-netbsdaout builds completely except for gas, where the target is deprecated. [1]: https://mail-index.netbsd.org/tech-toolchain/2021/07/19/msg004025.html --- bfd/config.bfd | 43 +++++++++++++-------- bfd/configure.ac | 5 +-- binutils/testsuite/binutils-all/nm.exp | 2 +- binutils/testsuite/lib/binutils-common.exp | 7 +--- config/picflag.m4 | 4 +- gas/configure.tgt | 9 +++-- gas/testsuite/gas/arm/blx-bl-convert.d | 2 +- gas/testsuite/gas/arm/blx-local-thumb.d | 2 +- gas/testsuite/gas/sh/basic.exp | 2 +- gdb/configure.host | 34 +++++++---------- gdb/configure.tgt | 2 +- gdb/testsuite/gdb.asm/asm-source.exp | 6 +-- intl/configure | 2 +- ld/configure.tgt | 44 +++++++++++----------- ld/testsuite/ld-arm/arm-elf.exp | 4 +- ld/testsuite/ld-elf/elf.exp | 2 +- ld/testsuite/ld-elf/shared.exp | 4 +- libiberty/configure | 4 +-
2021-08-11gdb: don't print backtrace when dumping core after an internal errorAndrew Burgess2-0/+41
Currently, when GDB hits an internal error, and the user selects to dump core, the recently added feature to write a backtrace to the console will kick in, and print a backtrace as well as dumping the core. This was certainly not my intention when adding the backtrace on fatal signal functionality, this feature was intended to produce a backtrace when GDB crashes due to some fatal signal, internal errors should have continued to behave as they did before, unchanged. In this commit I set the signal disposition of SIGABRT back to SIG_DFL just prior to the call to abort() that GDB uses to trigger the core dump, this prevents GDB reaching the code that writes the backtrace to the console. I've also added a test that checks we don't see a backtrace on the console after an internal error.
2021-08-11gdb: register SIGBUS, SIGFPE, and SIGABRT handlersAndrew Burgess2-2/+20
Register handlers for SIGBUS, SIGFPE, and SIGABRT. All of these signals are setup as fatal signals that will cause GDB to terminate. However, by passing these signals through the handle_fatal_signal function, a user can arrange to see a backtrace when GDB terminates (see maint set backtrace-on-fatal-signal). In normal use of GDB there should be no user visible changes after this commit. Only if GDB terminates with one of the above signals will GDB change slightly, potentially printing a backtrace before aborting. I've added new tests for SIGFPE, SIGBUS, and SIGABRT.
2021-08-11gdb: print backtrace on fatal SIGSEGVAndrew Burgess9-11/+398
This commit adds a new maintenance feature, the ability to print a (limited) backtrace if GDB dies due to a fatal signal. The backtrace is produced using the backtrace and backtrace_symbols_fd functions which are declared in the execinfo.h header, and both of which are async signal safe. A configure check has been added to check for these features, if they are not available then the new code is not compiled into GDB and the backtrace will not be printed. The motivation for this new feature is to aid in debugging GDB in situations where GDB has crashed at a users site, but the user is reluctant to share core files, possibly due to concerns about what might be in the memory image within the core file. Such a user might be happy to share a simple backtrace that was written to stderr. The production of the backtrace is on by default, but can switched off using the new commands: maintenance set backtrace-on-fatal-signal on|off maintenance show backtrace-on-fatal-signal Right now, I have hooked this feature in to GDB's existing handling of SIGSEGV only, but this will be extended to more signals in a later commit. One additional change I have made in this commit is that, when we decide GDB should terminate due to the fatal signal, we now raise the same fatal signal rather than raising SIGABRT. Currently, this is only effecting our handling of SIGSEGV. So, previously, if GDB hit a SEGV then we would terminate GDB with a SIGABRT. After this commit we will terminate GDB with a SIGSEGV. This feels like an improvement to me, we should still get a core dump, but in many shells, the user will see a more specific message once GDB exits, in bash for example "Segmentation fault" rather than "Aborted". Finally then, here is an example of the output a user would see if GDB should hit an internal SIGSEGV: Fatal signal: Segmentation fault ----- Backtrace ----- ./gdb/gdb[0x8078e6] ./gdb/gdb[0x807b20] /lib64/libpthread.so.0(+0x14b20)[0x7f6648c92b20] /lib64/libc.so.6(__poll+0x4f)[0x7f66484d3a5f] ./gdb/gdb[0x1540f4c] ./gdb/gdb[0x154034a] ./gdb/gdb[0x9b002d] ./gdb/gdb[0x9b014d] ./gdb/gdb[0x9b1aa6] ./gdb/gdb[0x9b1b0c] ./gdb/gdb[0x41756d] /lib64/libc.so.6(__libc_start_main+0xf3)[0x7f66484041a3] ./gdb/gdb[0x41746e] --------------------- 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) It is disappointing that backtrace_symbols_fd does not actually map the addresses back to symbols, this appears, in part, to be due to GDB not being built with -rdynamic as the manual page for backtrace_symbols_fd suggests, however, even when I do add -rdynamic to the build of GDB I only see symbols for some addresses. We could potentially look at alternative libraries to provide the backtrace (e.g. libunwind) however, the solution presented here, which is available as part of glibc is probably a good baseline from which we might improve things in future.
2021-08-11gdb: rename async_init_signals to gdb_init_signalsAndrew Burgess3-29/+16
The async_init_signals has, for some time, dealt with async and sync signals, so removing the async prefix makes sense I think. Additionally, as pointed out by Pedro: ..... The comments relating to SIGTRAP and SIGQUIT within this function are out of date. The comments for SIGTRAP talk about the signal disposition (SIG_IGN) being passed to the inferior, meaning the signal disposition being inherited by GDB's fork children. However, we now call restore_original_signals_state prior to forking, so the comment on SIGTRAP is redundant. The comments for SIGQUIT are similarly out of date, further, the comment on SIGQUIT talks about problems with BSD4.3 and vfork, however, we have not supported BSD4.3 for several years now. Given the above, it seems that changing the disposition of SIGTRAP is no longer needed, so I've deleted the signal() call for SIGTRAP. Finally, the header comment on the function now called gdb_init_signals was getting quite out of date, so I've updated it to (hopefully) better reflect reality. There should be no user visible change after this commit.
2021-08-11gdb: register signal handler after setting up event tokenAndrew Burgess1-3/+5
This commit fixes the smallest of small possible bug related to signal handling. If we look in async_init_signals we see code like this: signal (SIGQUIT, handle_sigquit); sigquit_token = create_async_signal_handler (async_do_nothing, NULL, "sigquit"); Then if we look in handle_sigquit we see code like this: mark_async_signal_handler (sigquit_token); signal (sig, handle_sigquit); Finally, in mark_async_signal_handler we have: async_handler_ptr->ready = 1; Where async_handler_ptr will be sigquit_token. What this means is that if a SIGQUIT arrive in async_init_signals after handle_sigquit has been registered, but before sigquit_token has been initialised, then GDB will most likely crash. The chance of this happening is tiny, but fixing this is trivial, just ensure we call create_async_signal_handler before calling signal, so lets do that. There are no tests for this. Trying to land a signal in the right spot is pretty hit and miss. I did try changing the current HEAD GDB like this: signal (SIGQUIT, handle_sigquit); raise (SIGQUIT); sigquit_token = create_async_signal_handler (async_do_nothing, NULL, "sigquit"); And confirmed that this did result in a crash, after my change I tried this: sigquit_token = create_async_signal_handler (async_do_nothing, NULL, "sigquit"); signal (SIGQUIT, handle_sigquit); raise (SIGQUIT); And GDB now starts up just fine. gdb/ChangeLog: * event-top.c (async_init_signals): For each signal, call signal only after calling create_async_signal_handler.
2021-08-11gdb: terminate upon receipt of SIGFPEAndrew Burgess1-24/+1
GDB's SIGFPE handling is broken, this is PR gdb/16505 and PR gdb/17891. We currently try to use an async event token to process SIGFPE. So, when a SIGFPE arrives the signal handler calls mark_async_signal_handler then returns, effectively ignoring the signal (for now). The intention is that later the event loop will see that the async token associated with SIGFPE has been marked and will call the async handler, which just throws an error. The problem is that SIGFPE is not safe to ignore. Ignoring a SIGFPE (unless it is generated artificially, e.g. by raise()) is undefined behaviour, after ignoring the signal on many targets we return to the instruction that caused the SIGFPE to be raised, which immediately causes another SIGFPE to be raised, we get stuck in an infinite loop. The behaviour is certainly true on x86-64. To view this behaviour I simply added some dummy code to GDB that performed an integer divide by zero, compiled this on x86-64 GNU/Linux, ran GDB and saw GDB hang. In this commit, I propose to remove all special handling of SIGFPE and instead just let GDB make use of the default SIGFPE action, that is, to terminate the process. The only user visible change here should be: - If a user sends a SIGFPE to GDB using something like kill, previously GDB would just print an error and remain alive, now GDB will terminate. This is inline with what happens if the user sends GDB a SIGSEGV from kill though, so I don't see this as an issue. - If a bug in GDB causes a real SIGFPE, previously the users GDB session would hang. Now the GDB session will terminate. Again, this is inline with what happens if GDB receives a SIGSEGV due to an internal bug. In bug gdb/16505 there is mention that it would be nice if GDB did more than just terminate when receiving a fatal signal. I haven't done that in this commit, but later commits will move in that direction. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=16505 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=17891
2021-08-10Ignore .debug_types when reading .debug_arangesTom Tromey2-1/+8
I noticed that the fission-reread.exp test case can cause a complaint when run with --target_board=cc-with-debug-names: warning: Section .debug_aranges in [...]/fission-reread has duplicate debug_info_offset 0x0, ignoring .debug_aranges. The bug here is that this executable has both .debug_info and .debug_types, and both have a CU at offset 0x0. This triggers the duplicate warning. Because .debug_types doesn't provide any address ranges, these CUs can be ignored. That is, this bug turns out to be another regression from the info/types merger patch. This patch fixes the problem by having this loop igore type units. fission-reread.exp is updated to test for the bug.
2021-08-10Generalize addrmap dumpingTom Tromey3-51/+46
While debugging another patch series, I wanted to dump an addrmap. I came up with this patch, which generalizes the addrmap-dumping code from psymtab.c and moves it to addrmap.c. psymtab.c is changed to use the new code.
2021-08-10gdb: iterate only on vfork parent threads in handle_vfork_child_exec_or_exitSimon Marchi1-17/+12
I spotted what I think is a buglet in proceed_after_vfork_done. After a vfork child exits or execs, we resume all the threads of the parent. To do so, we iterate on all threads using iterate_over_threads with the proceed_after_vfork_done callback. Each thread is resumed if the following condition is true: if (thread->ptid.pid () == pid && thread->state == THREAD_RUNNING && !thread->executing && !thread->stop_requested && thread->stop_signal () == GDB_SIGNAL_0) where `pid` is the pid of the vfork parent. This is not multi-target aware: since it only filters on pid, if there is an inferior with the same pid in another target, we could end up resuming a thread of that other inferior. The chances of the stars aligning for this to happen are tiny, but still. Fix that by iterating only on the vfork parent's threads, instead of on all threads. This is more efficient, as we iterate on just the required threads (inferiors have their own thread list), and we can drop the pid check. The resulting code is also more straightforward in my opinion, so it's a win-win. Change-Id: I14647da72e2bf65592e82fbe6efb77a413a4be3a
2021-08-09guile: fix smob exportsGeorge Barrett2-1/+56
Before Guile v2.1 [1], calls to `scm_make_smob_type' implicitly added the created class to the exports list of (oop goops); v2.1+ does not implicitly create bindings in any modules. This means that the GDB manual subsection documenting exported types is not quite right when GDB is linked against Guile <v2.1 (types are exported from (oop goops)) instead of (gdb)) and incorrect when linked against Guile v2.1+ (types are not bound to any variables at all!). There is a range of cases in which it's necessary or convenient to be able to refer to a GDB smob type, for instance: - Pattern matching based on the type of a value. - Defining GOOPS methods handling values from GDB (GOOPS methods typically use dynamic dispatch based on the types of the arguments). - Type-checking assertions when applying some defensive programming on an interface. - Generally any other situation one might encounter in a dynamically typed language that might need some introspection. If you're more familiar with Python, it would be quite similar to being unable to refer to the classes exported from the GDB module (which is to say: not crippling for the most part, but makes certain tasks more difficult than necessary). This commit makes a small change to GDB's smob registration machinery to make sure registered smobs get exported from the current module. This will likely cause warnings to the user about conflicting exports if they load both (gdb) and (oop goops) from a GDB linked against Guile v2.0, but it shouldn't impact functionality (and seemed preferable to trying to un-export bindings from (oop goops) if v2.0 was detected). [1]: This changed with Guile commit 28d0871b553a3959a6c59e2e4caec1c1509f8595 gdb/ChangeLog: 2021-06-07 George Barrett <bob@bob131.so> * guile/scm-gsmob.c (gdbscm_make_smob_type): Export registered smob type from the current module. gdb/testsuite/ChangeLog: 2021-06-07 George Barrett <bob@bob131.so> * gdb.guile/scm-gsmob.exp (test exports): Add tests to make sure the smob types currently listed in the GDB manual get exported from the (gdb) module. Change-Id: I7dcd791276b48dfc9edb64fc71170bbb42a6f6e7
2021-08-08Include objfiles.h in a few .c filesTom Tromey3-0/+3
I found a few .c files that rely on objfiles.h, but that only include it indirectly, via dwarf2/read.h -> psympriv.h. If that include is removed (something my new DWARF indexer series does), then the build will break. It seemed harmless and correct to add these includes now, making the eventual series a little smaller.
2021-08-06[gdb/symtab] Recognize .gdb_index symbol table with empty entries as emptyTom de Vries2-20/+11
When reading a .gdb_index that contains a non-empty symbol table with only empty entries, gdb doesn't recognize it as empty. Fix this by recognizing that the constant pool is empty, and then setting the symbol table to empty. Tested on x86_64-linux. gdb/ChangeLog: 2021-08-01 Tom de Vries <tdevries@suse.de> PR symtab/28159 * dwarf2/read.c (read_gdb_index_from_buffer): Handle symbol table filled with empty entries. gdb/testsuite/ChangeLog: 2021-08-01 Tom de Vries <tdevries@suse.de> PR symtab/28159 * gdb.dwarf2/dw2-zero-range.exp: Remove kfail.
2021-08-06Unconditionally define _initialize_addrmapTom Tromey1-1/+3
The way that init.c is generated does not allow for an initialization function to be conditionally defined -- doing so will result in a link error. This patch fixes a build problem that arises from such a conditional definition. It can be reproduce with --disable-unit-tests.
2021-08-06[gdb/symtab] Fix zero address complaint for shlibTom de Vries4-8/+232
In PR28004 the following warning / Internal error is reported: ... $ gdb -q -batch \ -iex "set sysroot $(pwd -P)/repro" \ ./repro/gdb \ ./repro/core \ -ex bt ... Program terminated with signal SIGABRT, Aborted. #0 0x00007ff8fe8e5d22 in raise () from repro/usr/lib/libc.so.6 [Current thread is 1 (LWP 1762498)] #1 0x00007ff8fe8cf862 in abort () from repro/usr/lib/libc.so.6 warning: (Internal error: pc 0x7ff8feb2c21d in read in psymtab, \ but not in symtab.) warning: (Internal error: pc 0x7ff8feb2c218 in read in psymtab, \ but not in symtab.) ... #2 0x00007ff8feb2c21e in __gnu_debug::_Error_formatter::_M_error() const \ [clone .cold] (warning: (Internal error: pc 0x7ff8feb2c21d in read in \ psymtab, but not in symtab.) ) from repro/usr/lib/libstdc++.so.6 ... The warning is about the following: - in find_pc_sect_compunit_symtab we try to find the address (0x7ff8feb2c218 / 0x7ff8feb2c21d) in the symtabs. - that fails, so we try again in the partial symtabs. - we find a matching partial symtab - however, the partial symtab has a full symtab, so we should have found a matching symtab in the first step. The addresses are: ... (gdb) info sym 0x7ff8feb2c218 __gnu_debug::_Error_formatter::_M_error() const [clone .cold] in \ section .text of repro/usr/lib/libstdc++.so.6 (gdb) info sym 0x7ff8feb2c21d __gnu_debug::_Error_formatter::_M_error() const [clone .cold] + 5 in \ section .text of repro/usr/lib/libstdc++.so.6 ... which correspond to unrelocated addresses 0x9c218 and 0x9c21d: ... $ nm -C repro/usr/lib/libstdc++.so.6.0.29 | grep 000000000009c218 000000000009c218 t __gnu_debug::_Error_formatter::_M_error() const \ [clone .cold] ... which belong to function __gnu_debug::_Error_formatter::_M_error() in /build/gcc/src/gcc/libstdc++-v3/src/c++11/debug.cc. The partial symtab that is found for the addresses is instead the one for /build/gcc/src/gcc/libstdc++-v3/src/c++98/bitmap_allocator.cc, which is incorrect. This happens as follows. The bitmap_allocator.cc CU has DW_AT_ranges at .debug_rnglist offset 0x4b50: ... 00004b50 0000000000000000 0000000000000056 00004b5a 00000000000a4790 00000000000a479c 00004b64 00000000000a47a0 00000000000a47ac ... When reading the first range 0x0..0x56, it doesn't trigger the "start address of zero" complaint here: ... /* A not-uncommon case of bad debug info. Don't pollute the addrmap with bad data. */ if (range_beginning + baseaddr == 0 && !per_objfile->per_bfd->has_section_at_zero) { complaint (_(".debug_rnglists entry has start address of zero" " [in module %s]"), objfile_name (objfile)); continue; } ... because baseaddr != 0, which seems incorrect given that when loading the shared library individually in gdb (and consequently baseaddr == 0), we do see the complaint. Consequently, we run into this case in dwarf2_get_pc_bounds: ... if (low == 0 && !per_objfile->per_bfd->has_section_at_zero) return PC_BOUNDS_INVALID; ... which then results in this code in process_psymtab_comp_unit_reader being called with cu_bounds_kind == PC_BOUNDS_INVALID, which sets the set_addrmap argument to 1: ... scan_partial_symbols (first_die, &lowpc, &highpc, cu_bounds_kind <= PC_BOUNDS_INVALID, cu); ... and consequently, the CU addrmap gets build using address info from the functions. During that process, addrmap_set_empty is called with a range that includes 0x9c218 and 0x9c21d: ... (gdb) p /x start $7 = 0x9989c (gdb) p /x end_inclusive $8 = 0xb200d ... but it's called for a function at DIE 0x54153 with DW_AT_ranges at 0x40ae: ... 000040ae 00000000000b1ee0 00000000000b200e 000040b9 000000000009989c 00000000000998c4 000040c3 <End of list> ... and neither range includes 0x9c218 and 0x9c21d. This is caused by this code in partial_die_info::read: ... if (dwarf2_ranges_read (ranges_offset, &lowpc, &highpc, cu, nullptr, tag)) has_pc_info = 1; ... which pretends that the function is located at addresses 0x9989c..0xb200d, which is indeed not the case. This patch fixes the first problem encountered: fix the "start address of zero" complaint warning by removing the baseaddr part from the condition. Same for dwarf2_ranges_process. The effect is that: - the complaint is triggered, and - the warning / Internal error is no longer triggered. This does not fix the observed problem in partial_die_info::read, which is filed as PR28200. Tested on x86_64-linux. Co-Authored-By: Simon Marchi <simon.marchi@polymtl.ca> gdb/ChangeLog: 2021-07-29 Simon Marchi <simon.marchi@polymtl.ca> Tom de Vries <tdevries@suse.de> PR symtab/28004 * gdb/dwarf2/read.c (dwarf2_rnglists_process, dwarf2_ranges_process): Fix zero address complaint. * gdb/testsuite/gdb.dwarf2/dw2-zero-range-shlib.c: New test. * gdb/testsuite/gdb.dwarf2/dw2-zero-range.c: New test. * gdb/testsuite/gdb.dwarf2/dw2-zero-range.exp: New file.
2021-08-05[PATCH] GDB Testsuite, update compile-cplus.expWill Schmidt1-5/+4
[PATCH] GDB Testsuite, update compile-cplus.exp Update the gdb.compile/compile-cplus.exp test to handle errors generated when passing bad arguments into the gdb-compile command. This matches changes made to gdb.compile/compile.exp in the past as part of "Migrate rest of compile commands to new options framework" e6ed716cd5514c08b9d7c469d185b1aa177dbc22
2021-08-05[gdb] Handle .TOC. sections during gdb-compile for rs6000 target.Will Schmidt1-0/+41
[gdb] Handle .TOC. sections during gdb-compile for rs6000 target. When we encounter a .TOC. symbol in the object we are loading, we need to associate this with the .toc section in order to properly resolve other symbols in the object. IF a .toc section is not found, iterate the sections until we find one with the SEC_ALLOC flag. If that also fails, fall back to using the *ABS* section, pointed to by bfd_abs_section_ptr.