Since https://github.com/llvm/llvm-project/pull/109628 landed, this test
has been failing on 32-bit Arm.
This is due to a codegen problem (whether added or uncovered by the change,
not known) where the trap instruction is placed after the frame pointer
and link register are restored.
https://github.com/llvm/llvm-project/issues/113154
So the code was:
```
std::__1::vector<int>::operator[](unsigned int):
sub sp, sp, #8
str r0, [sp, #4]
str r1, [sp]
add sp, sp, #8
.inst 0xe7ffdefe
bx lr
```
When lldb saw the trap, the PC was inside operator[] but the frame
information actually pointed to g.
This bug only happens for leaf functions so adding a return type
works around it:
```
std::__1::vector<int>::operator[](unsigned int):
push {r11, lr}
mov r11, sp
sub sp, sp, #8
str r0, [sp, #4]
str r1, [sp]
mov sp, r11
pop {r11, lr}
.inst 0xe7ffdefe
bx lr
```
(and operator[] should return T& anyway)
Now the PC location and frame information should match and the
test passes.
This attempts to improve user-experience when LLDB stops on a
verbose_trap. Currently if a `__builtin_verbose_trap` triggers, we
display the first frame above the call to the verbose_trap. So in the
newly added test case, we would've previously stopped here:
```
(lldb) run
Process 28095 launched: '/Users/michaelbuch/a.out' (arm64)
Process 28095 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = Bounds error: out-of-bounds access
frame #1: 0x0000000100003f5c a.out`std::__1::vector<int>::operator[](this=0x000000016fdfebef size=0, (null)=10) at verbose_trap.cpp:6:9
3 template <typename T>
4 struct vector {
5 void operator[](unsigned) {
-> 6 __builtin_verbose_trap("Bounds error", "out-of-bounds access");
7 }
8 };
```
After this patch, we would stop in the first non-`std` frame:
```
(lldb) run
Process 27843 launched: '/Users/michaelbuch/a.out' (arm64)
Process 27843 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = Bounds error: out-of-bounds access
frame #2: 0x0000000100003f44 a.out`g() at verbose_trap.cpp:14:5
11
12 void g() {
13 std::vector<int> v;
-> 14 v[10];
15 }
16
```
rdar://134490328
This patch adds a frame recognizer for Clang's
`__builtin_verbose_trap`, which behaves like a
`__builtin_trap`, but emits a failure-reason string into debug-info in
order for debuggers to display
it to a user.
The frame recognizer triggers when we encounter
a frame with a function name that begins with
`__clang_trap_msg`, which is the magic prefix
Clang emits into debug-info for verbose traps.
Once such frame is encountered we display the
frame function name as the `Stop Reason` and display that frame to the
user.
Example output:
```
(lldb) run
warning: a.out was compiled with optimization - stepping may behave oddly; variables may not be available.
Process 35942 launched: 'a.out' (arm64)
Process 35942 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = Misc.: Function is not implemented
frame #1: 0x0000000100003fa4 a.out`main [inlined] Dummy::func(this=<unavailable>) at verbose_trap.cpp:3:5 [opt]
1 struct Dummy {
2 void func() {
-> 3 __builtin_verbose_trap("Misc.", "Function is not implemented");
4 }
5 };
6
7 int main() {
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = Misc.: Function is not implemented
frame #0: 0x0000000100003fa4 a.out`main [inlined] __clang_trap_msg$Misc.$Function is not implemented$ at verbose_trap.cpp:0 [opt]
* frame #1: 0x0000000100003fa4 a.out`main [inlined] Dummy::func(this=<unavailable>) at verbose_trap.cpp:3:5 [opt]
frame #2: 0x0000000100003fa4 a.out`main at verbose_trap.cpp:8:13 [opt]
frame #3: 0x0000000189d518b4 dyld`start + 1988
```
selecting the "Most relevant" frame.
If you don't do that, then the correct frame gets selected, but it
happens AFTER the frame info gets printed in the stop message, so
you don't see the selected frame.
The test for this hid the issue because it ran `frame info` and
checked the result of that. That happens after the recognizer selects
the frame, and so it was right. But if the recognizer is working
correctly it will have already done the same printing in the stop
message, and this way we also verify that the stop message was right.
Differential Revision: https://reviews.llvm.org/D150315
The test is `UNSUPPORTED: system-linux` so the XFAIL for linux is
redundant.
Part of the project to eliminate special handling for triples in lit
expressions.
Differential Revision: https://reviews.llvm.org/D139734
The new FreeBSDRemote plugin has reached feature parity on i386
and amd64 targets. Use it by default on these architectures, while
allowing the use of the legacy plugin via FREEBSD_LEGACY_PLUGIN envvar.
Revisit the method of switching plugins. Apparently, the return value
of PlatformFreeBSD::CanDebugProcess() is what really decides whether
the legacy or the new plugin is used.
Update the test status. Reenable the tests that were previously
disabled on FreeBSD and do not cause hangs or are irrelevant to FreeBSD.
Mark all tests that fail reliably as expectedFailure. For now, tests
that are flaky (i.e. produce unstable results) are left enabled
and cause unpredictable test failures.
Differential Revision: https://reviews.llvm.org/D90757
The `frame recognizer` command only exists when Python scripting is
enabled. Therefore the test should be made conditional on Python.
Without it, the test fails with "'frame recognizer' is not a known
command."
This patch marks following tests as xfail for arm-linux target.
lldb/test/API/functionalities/load_using_paths/TestLoadUsingPaths.py
lldb/test/API/python_api/thread/TestThreadAPI.py
lldb/test/Shell/Recognizer/assert.test
Bugs have been filed for all of them for the corresponding failing
component.
This reimplements commit 6b2979c12300b90a1e69791d43ee9cff14f4265e and updates
the tests to reflect the addition of the alternate symbol attribute.
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
D73303 was failing on Fedora Linux and so it was disabled by Skip the
AssertFrameRecognizer test for Linux.
I find no easy way how to find out if it gets recognized as
`__assert_fail` or `__GI___assert_fail` as during `Process` ctor
libc.so.6 is not yet loaded by the debuggee.
DWARF symbol `__GI___assert_fail` overrides the ELF symbol `__assert_fail`.
While external debug info (=DWARF) gets disabled for testsuite (D55859)
that sure does not apply for real world usage.
Differential Revision: https://reviews.llvm.org/D74252
This reverts commit cf1046c716b33ed449aa8fc26376864917c63c25.
Reverted: https://reviews.llvm.org/D74252
It fixed testsuite but broke real world functionality where is not used:
settings set symbols.enable-external-lookup false
D73303 was failing on Fedora Linux and so it was disabled by Skip the
AssertFrameRecognizer test for Linux.
On Fedora 30 x86_64 I have:
$ readelf -Ws /lib64/libc.so.6 |grep '^Symbol\|.*assert_fail'
Symbol table '.dynsym' contains 2362 entries:
630: 0000000000030520 70 FUNC GLOBAL DEFAULT 14 __assert_fail@@GLIBC_2.2.5
Symbol table '.symtab' contains 22711 entries:
922: 000000000002275a 15 FUNC LOCAL DEFAULT 14 __assert_fail_base.cold
18044: 0000000000030520 70 FUNC LOCAL DEFAULT 14 __GI___assert_fail
20081: 00000000000303a0 370 FUNC LOCAL DEFAULT 14 __assert_fail_base
21766: 0000000000030520 70 FUNC GLOBAL DEFAULT 14 __assert_fail
The patch should never expect __GI___assert_fail:
.symtab can be present or not but that should not change that
__assert_fail always wins - it is always present from .dynsym and it can
never be overriden by __GI___assert_fail as __GI___assert_fail has only
local binding. Global binding is preferred since D63540.
External debug info symbols do not matter since D55859 (and DWARF should
never be embedded in system libc.so.6).
Differential Revision: https://reviews.llvm.org/D74252
This patch skips the AssertFrameRecognizer test for Linux since it appears to
fail on certain distributions (AFAIK Fedora & ArchLinux).
The failure happen because the thread don't set the current frame to
the most relevant one. So the stopped location doesn't match with what
the test is expecting.
The test will be enabled again after I'll be able to reproduce the failure
on one of those platform and fix the issue.
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
When a thread stops, this checks depending on the platform if the top frame is
an abort stack frame. If so, it looks for an assert stack frame in the upper
frames and set it as the most relavant frame when found.
To do so, the StackFrameRecognizer class holds a "Most Relevant Frame" and a
"cooked" stop reason description. When the thread is about to stop, it checks
if the current frame is recognized, and if so, it fetches the recognized frame's
attributes and applies them.
rdar://58528686
Differential Revision: https://reviews.llvm.org/D73303
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
When a thread stops, this checks depending on the platform if the top frame is
an abort stack frame. If so, it looks for an assert stack frame in the upper
frames and set it as the most relavant frame when found.
To do so, the StackFrameRecognizer class holds a "Most Relevant Frame" and a
"cooked" stop reason description. When the thread is about to stop, it checks
if the current frame is recognized, and if so, it fetches the recognized frame's
attributes and applies them.
rdar://58528686
Differential Revision: https://reviews.llvm.org/D73303
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
When a thread stops, this checks depending on the platform if the top frame is
an abort stack frame. If so, it looks for an assert stack frame in the upper
frames and set it as the most relavant frame when found.
To do so, the StackFrameRecognizer class holds a "Most Relevant Frame" and a
"cooked" stop reason description. When the thread is about to stop, it checks
if the current frame is recognized, and if so, it fetches the recognized frame's
attributes and applies them.
rdar://58528686
Differential Revision: https://reviews.llvm.org/D73303
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
