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mulle-lldb needs a stackframe to evaluate Objective-C code #4
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codeon-nat
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Normally, LLDB is creating a high-fidelity representation of a live process, including a list of modules and sections, with the associated memory address ranges. In order to build the module and section map LLDB tries to locate the local module image (object file) and will parse it. This does not work for postmortem debugging scenarios where the crash dump (minidump in this case) was captured on a different machine. Fortunately the minidump format encodes enough information about each module's memory range to allow us to create placeholder modules. This enables most LLDB functionality involving address-to-module translations. Also, we may want to completly disable the search for matching local object files if we load minidumps unless we can prove that the local image matches the one from the crash origin. (not part of this change, see: llvm.org/pr35193) Example: Identify the module from a stack frame PC: Before: thread #1, stop reason = Exception 0xc0000005 encountered at address 0x164d14 frame #0: 0x00164d14 frame #1: 0x00167c79 frame #2: 0x00167e6d frame #3: 0x7510336a frame #4: 0x77759882 frame #5: 0x77759855 After: thread #1, stop reason = Exception 0xc0000005 encountered at address 0x164d14 frame #0: 0x00164d14 C:\Users\amccarth\Documents\Visual Studio 2013\Projects\fizzbuzz\Debug\fizzbuzz.exe frame #1: 0x00167c79 C:\Users\amccarth\Documents\Visual Studio 2013\Projects\fizzbuzz\Debug\fizzbuzz.exe frame #2: 0x00167e6d C:\Users\amccarth\Documents\Visual Studio 2013\Projects\fizzbuzz\Debug\fizzbuzz.exe frame #3: 0x7510336a C:\Windows\SysWOW64\kernel32.dll frame #4: 0x77759882 C:\Windows\SysWOW64\ntdll.dll frame #5: 0x77759855 C:\Windows\SysWOW64\ntdll.dll Example: target modules list Before: error: the target has no associated executable images After: [ 0] C:\Windows\System32\MSVCP120D.dll [ 1] C:\Windows\SysWOW64\kernel32.dll [ 2] C:\Users\amccarth\Documents\Visual Studio 2013\Projects\fizzbuzz\Debug\fizzbuzz.exe [ 3] C:\Windows\System32\MSVCR120D.dll [ 4] C:\Windows\SysWOW64\KERNELBASE.dll [ 5] C:\Windows\SysWOW64\ntdll.dll NOTE: the minidump format also includes the debug info GUID, so we can fill-in the module UUID from it, but this part was excluded from this change to keep the changes simple (the LLDB UUID is hardcoded to be either 16 or 20 bytes, while the CodeView GUIDs are normally 24 bytes) Differential Revision: https://reviews.llvm.org/D45700 git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@330302 91177308-0d34-0410-b5e6-96231b3b80d8
codeon-nat
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Oct 15, 2019
logging messages that are written the same, making it difficult to
know for certain which code path was taken based on a logfile. Add
some words to make each unique.
Right now the ordering for finding a FullUnwindPlan (ignoring
fallback unwind plan logic) is
1. If this is a _sigtramp like function, try eh_frame which is
hand written on darwin systems to account for finding the
saved register context correctly.
2. Ask the DynamicLoader if eh_frame should be preferred for
this frame. Some binaries on the system may have hand-written
eh_frame and the DynamicLoader is the source for this. (primarily
this is for hand-written assembly in the objc runtime, and we tell
lldb to trust that for functions in libobjc.dylib.)
3. if 0th frame, use GetUnwindPlanAtNonCallSite plan.
4. GetUnwindPlanAtCallSite {for 0th or any other}
5. GetUnwindPlanAtNonCallSite {now for non-0th frames, only if not from a compiler? hm.}
6. GetUnwindPlanArchitectureDefaultAtFunctionEntry if we're on the first instruction
7. Architectural default unwind plan ABI::CreateDefaultUnwindPlan
I'm moving #6 -- DefaultAtFunctionEntry -- up to between #3 and #4,
where we're already doing things specific to the zeroth frame. If
we're on the zeroth frame and the GetUnwindPlanAtNonCallSite plan
has failed for some reason, and we're on the first instruction, we
should definitely use DefaultAtFunctionEntry instead of any other
unwind plan. If we're trying to step out of some rando function
on the system that we couldn't assembly instruction inspect, this
is sufficient for us to step out of it.
git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@359847 91177308-0d34-0410-b5e6-96231b3b80d8
codeon-nat
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Oct 15, 2019
The arbitrary timeout when flushing GDB remote packets caused non-determinism and flakiness between test runs. I suspect it is what's causing the flakiness of the reproducer tests on GreenDragon, and want to see if removing it causes that to go away. This change was originally introduced in r197579 to discard a `$T02thread:01;#4` that QEMU was sending. If anybody knows how to test that this continues working after removing this code, I'd love to hear it. git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@364669 91177308-0d34-0410-b5e6-96231b3b80d8
codeon-nat
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This fixes a failing testcase on Fedora 30 x86_64 (regression Fedora 29->30):
PASS:
./bin/lldb ./lldb-test-build.noindex/functionalities/unwind/noreturn/TestNoreturnUnwind.test_dwarf/a.out -o 'settings set symbols.enable-external-lookup false' -o r -o bt -o quit
* frame #0: 0x00007ffff7aa6e75 libc.so.6`__GI_raise + 325
frame #1: 0x00007ffff7a91895 libc.so.6`__GI_abort + 295
frame #2: 0x0000000000401140 a.out`func_c at main.c:12:2
frame #3: 0x000000000040113a a.out`func_b at main.c:18:2
frame #4: 0x0000000000401134 a.out`func_a at main.c:26:2
frame #5: 0x000000000040112e a.out`main(argc=<unavailable>, argv=<unavailable>) at main.c:32:2
frame #6: 0x00007ffff7a92f33 libc.so.6`__libc_start_main + 243
frame #7: 0x000000000040106e a.out`_start + 46
vs.
FAIL - unrecognized abort() function:
./bin/lldb ./lldb-test-build.noindex/functionalities/unwind/noreturn/TestNoreturnUnwind.test_dwarf/a.out -o 'settings set symbols.enable-external-lookup false' -o r -o bt -o quit
* frame #0: 0x00007ffff7aa6e75 libc.so.6`.annobin_raise.c + 325
frame #1: 0x00007ffff7a91895 libc.so.6`.annobin_loadmsgcat.c_end.unlikely + 295
frame #2: 0x0000000000401140 a.out`func_c at main.c:12:2
frame #3: 0x000000000040113a a.out`func_b at main.c:18:2
frame #4: 0x0000000000401134 a.out`func_a at main.c:26:2
frame #5: 0x000000000040112e a.out`main(argc=<unavailable>, argv=<unavailable>) at main.c:32:2
frame #6: 0x00007ffff7a92f33 libc.so.6`.annobin_libc_start.c + 243
frame #7: 0x000000000040106e a.out`.annobin_init.c.hot + 46
The extra ELF symbols are there due to Annobin (I did not investigate why this problem happened specifically since F-30 and not since F-28).
It is due to:
Symbol table '.dynsym' contains 2361 entries:
Valu e Size Type Bind Vis Name
0000000000022769 5 FUNC LOCAL DEFAULT _nl_load_domain.cold
000000000002276e 0 NOTYPE LOCAL HIDDEN .annobin_abort.c.unlikely
...
000000000002276e 0 NOTYPE LOCAL HIDDEN .annobin_loadmsgcat.c_end.unlikely
...
000000000002276e 0 NOTYPE LOCAL HIDDEN .annobin_textdomain.c_end.unlikely
000000000002276e 548 FUNC GLOBAL DEFAULT abort
000000000002276e 548 FUNC GLOBAL DEFAULT abort@@GLIBC_2.2.5
000000000002276e 548 FUNC LOCAL DEFAULT __GI_abort
0000000000022992 0 NOTYPE LOCAL HIDDEN .annobin_abort.c_end.unlikely
Differential Revision: https://reviews.llvm.org/D63540
git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@364773 91177308-0d34-0410-b5e6-96231b3b80d8
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If no process is run yet, then there is no stack frame yet. The debugger can't derive a process from that (as it doesn't exist) and the interpretation of function-calls neccesarily fails.
This is probably not only related to mulle-lldb only.
Remedy:
Now you can evaluate.
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