Using a DexLimitSteps command forces dexter to use the ConditionalController
debugger controller. At each breakpoint the ConditionalController needs to
understand which one has been hit. Prior to this patch, upon hitting a
breakpoint, dexter used the current source location to look up which requested
breakpoint had been hit.
A breakpoint may not get set at the exact location that the user (dexter)
requests. For example, if the requested breakpoint location doesn't exist
in the line table then then debuggers will (usually, AFAICT) set the breakpoint
at the next available valid breakpoint location.
This meant that, occasionally in unoptimised programs and frequently in
optimised programs, the ConditionalController was failing to determine which
breakpoint had been hit.
This is the fix:
Change the DebuggerBase breakpoint interface to use opaque breakpoint ids
instead of using source location to identify breakpoints, and update the
ConditionalController to track breakpoints instead of locations.
These now return a breakpoint id:
add_breakpoint(self, file_, line)
_add_breakpoint(self, file_, line)
add_conditional_breakpoint(self, file_, line, condition)
_add_conditional_breakpoint(self, file_, line, condition)
Replace:
delete_conditional_breakpoint(self, file_, line, condition)
_delete_conditional_breakpoint(self, file_, line, condition)
with:
delete_breakpoint(self, id)
Add:
get_triggered_breakpoint_ids(self)
A breakpoint id is guaranteed to be unique for each requested breakpoint, even
for duplicate breakpoint requests. Identifying breakpoints like this, instead
of by location, removes the possibility of mixing up requested and bound
breakpoints.
This closely matches the LLDB debugger interface so little work was required in
LLDB.py, but some extra bookkeeping is required in VisualStudio.py to maintain
the new breakpoint id semantics. No implementation work has been done in
dbgeng.py as DexLimitSteps doesn't seem to support dbgeng at the moment.
Testing
Added:
dexter/feature_tests/commands/perfect/limit_steps/limit_steps_line_mismatch.cpp
There were no unexpected failures running the full debuginfo-tests suite.
The regression tests use dbgeng on windows by default, and as mentioned above
dbgeng isn't supported yet, so I have also manually tested (i.e. without lit)
that this specific test works as expected with clang and Visual Studio 2017 on
Windows.
Reviewed By: TWeaver
Differential Revision: https://reviews.llvm.org/D98699
The test optnone-simple-functions.cpp added in D97668 fails on macOS.
os.path.exists raises an exception because we pass it None. Guard against this.
Related revision: https://reviews.llvm.org/D97668
Add dexter tests using the optnone attribute in various scenarios. Our users
have found optnone useful when debugging optimised code. We have these tests
downstream (and one upstream already: D89873) and we would like to contribute
them if there is any interest.
The tests are fairly self explanatory. Testing optnone with:
* optnone-fastmath.cpp: floats and -ffast-math,
* optnone-simple-functions: simple functions and integer arithmetic,
* optnone-struct-and-methods: a struct with methods,
* optnone-vectors-and-functions: templates and integer vector arithmetic.
optnone-vectors-and-functions contains two FIXMEs. The first problem is that
lldb seems to struggle with evaluating expressions with the templates used
here (example below). Perhaps this is PR42920?
(lldb) p TypeTraits<int __attribute__((ext_vector_type(4)))>::NumElements
error: <user expression 0>:1:1: no template named 'TypeTraits'
TypeTraits<int __attribute__((ext_vector_type(4)))>::NumElements
^
The second is that while lldb cannot evaluate the following expression, gdb
can, but it reports that the variable has been optimzed away. It does this when
compiling at O0 too. llvm-dwarfdump shows that MysteryNumber does have a
location. I don't know whether the DIE is bad or if both debuggers just don't
support it.
TypeTraits<int __attribute__((ext_vector_type(4)))>::MysteryNumber
DW_TAG_variable
DW_AT_specification (0x0000006b "MysteryNumber")
DW_AT_location (DW_OP_addr 0x601028)
DW_AT_linkage_name ("_ZN10TypeTraitsIDv4_iE13MysteryNumberE")
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D97668
Allow users to use a non-system version of perl, python and awk, which is useful
in certain package managers.
Reviewed By: JDevlieghere, MaskRay
Differential Revision: https://reviews.llvm.org/D95119
If the default target and host triple don't match then print the following
message when the lit test runs:
Forcing dexter tests to use host triple {HOST_TRIPLE}.
If we can't target the host arch then, when lit runs, we mark
the dexter test directories as UNSUPPORTED and print the message:
Host triple {HOST_TRIPLE} not supported. Skipping dexter tests in
the debuginfo-tests project.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D96494
This test was accidently removed when the directory structure was shuffled
around for dexter in f78c236efd.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D96968
LLVM has a minimum requirement of python 3.6 now, and Python is
explicitly checked for in the LLVM CMakeLists.txt, so this check is no
longer needed here.
Differential Revision: https://reviews.llvm.org/D96499
Reviewed by: aprantl
The '%dexter_regression_test' substitution was missing quotes around the
python executable, unlike other substitutions of a similar nature in the
file. This changes fixes the issue.
Differential Revision: https://reviews.llvm.org/D96420
Reviewed by: jmorse, aganea
Since the new pass manager has been enabled by default these tests had their
-O1 variations failing due to the tested functions being inlined. This just
adds no_inline to the respective code similar to what we did in other
tests (e.g. aa56b30014 ).
This reverts commit 511dd4f438 along with
a couple fixes.
Original message:
Now the context is the first, rather than the last input.
This better matches the rest of the infrastructure and makes
it easier to move these types to being declaratively specified.
Phabricator: https://reviews.llvm.org/D96111
This method of the dbgeng debugger driver used to just "pass", as setting
dbgeng free running still leads to numerous errors. This wasn't a problem
in the past because, as it turns out, nothing called the go method.
However, a recent refactor uses it.
Rather than launch dbgeng free running, instead have it single step one
step forwards. This is slow, but it makes progress, where previously we
weren't.
Differential Revision: https://reviews.llvm.org/D91737
Tweak dexter-tests/memvars/inline-escaping-function.c added in D94761
(b7e516202e) by adding a 'param' use after the merge point. The test XFAILS
with and without this change, but without it the test looks very similar to
memvars/unused-merged-value.c. The test now demonstrates the problem more
clearly.
These dexter tests illustrate PR48719, the summary of which is:
Sometimes we insert dbg.values for merged values (PHIs) when promoting
variables, sometimes we don't. Sometimes there is no PHI because the merged
value is never used. It doesn't matter because LiveDebugValues understands these
merged values (implicit or otherwise) and correctly updates the debug
info. Importantly, these merged variable values (which may or may not exist as
PHIs, and may or not be represented with dbg.values) are //always// implicitly
defined by the combination of incoming edges and the incoming variable locations
along those edges by virtue of LiveDebugValues existing. Unfortunately, it is
possible to mess with the CFG and remove / move these edges before
LiveDebugValues runs. In this case our debug info model only works when the
merged value is tracked by a dbg.value. Currently, this is only done rigorously
for variables which are A) promoted in the first round of mem2reg and B) are
used after the merge point.
As an example, compile the following source with -O3 -g and step through with a
debugger. You will see parama=5 throughout the function fun which is incorrect -
we expect to see param=20 after the conditional assignment.
__attribute__((optnone))
void esc(int* p) {}
__attribute__((optnone))
void fluff() {}
__attribute__((noinline))
int fun(int parama, int paramb) {
if (parama)
parama = paramb;
fluff(); // DexLabel('s0')
esc(¶ma);
return 0;
}
int main() {
return fun(5, 20);
}
1. parama is escaped by esc(¶ma) so it is not promoted by
SROA/mem2reg (failing condition "A" above).
2. InstCombine's LowerDbgDeclare converts the dbg.declare to a set of
dbg.values (tracking the stored SSA values).
3. InstCombine replaces the two stores to parama's alloca (the initial
parameter register store in entry and the assignment in if.then) with a
PHI+store in the common sucessor.
4. SimplifyCFG folds the blocks together and converts the PHI to a
select.
The debug info is not updated to account for the merged value in the successor
prior to SimplifyCFG when it exists as a PHI, or during when it becomes a
select.
As with D89543, which added some dexter tests for escaped locals, the idea is
to build a set of source-level tests which highlights existing issues and
might be useful in evaluating a new debug info model.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D94761
This is part of a larger refactoring the better congregates the builtin structures under the BuiltinDialect. This also removes the problematic "standard" naming that clashes with the "standard" dialect, which is not defined within IR/. A temporary forward is placed in StandardTypes.h to allow time for downstream users to replaced references.
Differential Revision: https://reviews.llvm.org/D92435
Adds visual studio debugger support to dexter via option --debugger vs2019
Differential Revision: https://reviews.llvm.org/D89803
Author: Nabeel Omer <nabeel.omer@sony.com>
both deferred_globals.cpp namespace.cpp require lldb in order to run and will
fail if it's not available.
add the required lines to the top of the tests.
deferred_globals.cpp: Verify that debug information for a local variable does
not hide a global definition that has the same name
namespace.cpp: Ensure that the debug information for a global variable
includes namespace information.
Differential Revision: https://reviews.llvm.org/D89462
Author: Nabeel Omer <nabeel.omer@sony.com>
Recently there has been renewed interest in improving debug-info for variables
that (partially or otherwise) live on the stack in optimised code.
At the moment instcombine speculates that stack slots are probably going to be
promoted to registers, and prepares the debug-info accordingly. It runs a
function called LowerDbgDeclare which converts dbg.declares to a set of
dbg.values after loads, and before stores and calls. Sometimes the stack
location remains (e.g. for escaped locals). If any dbg.values become undef
where the stack location is still valid we end up unnecessarily reducing
variable location coverage due to our inability to track multiple locations
simultaneously. There is a flag to disable this feature
(-instcombine-lower-dbg-declare=0), which prevents this conversion at the cost
of sometimes providing incorrect location info in the face of DSE, DCE, GVN,
CSE etc.
This has been discussed fairly extensively on PR34136.
The idea of these tests is to provide examples of situations that we should
consider when designing a new system, to aid discussions and eventually help
evaluate the implementation.
Dexter isn't ideal for observing specific optimisation behaviour. Writing an
exaustive test suite would be difficult, and the resultant suite would be
fragile. However, I think having some concrete executable examples is useful
at least as a reference.
Differential Revision: https://reviews.llvm.org/D89543
NFC patch simply updates the commands.md documentation contents with missing
links to the DexLimitSteps and DexLabel command documentation.
Differential Revision: https://reviews.llvm.org/D89689
Author: Nabeel Omer <nabeel.omer@sony.com>
This is the first bit from D73546. Primarily setting up the corresponding test. Will add more pretty printers in a separate revision.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D86937
Summary:
This allows to run dexter tests with separately compiled
binaries that are specified via --binary if the source file
location changed between compilation and dexter test run.
Reviewers: TWeaver, jmorse, probinson, #debug-info
Reviewed By: jmorse
Subscribers: #debug-info, cmtice, llvm-commits
Tags: #llvm, #debug-info
Differential Revision: https://reviews.llvm.org/D81319
Having the input dumped on failure seems like a better
default: I debugged FileCheck tests for a while without knowing
about this option, which really helps to understand failures.
Remove `-dump-input-on-failure` and the environment variable
FILECHECK_DUMP_INPUT_ON_FAILURE which are now obsolete.
Differential Revision: https://reviews.llvm.org/D81422
When passing a test path, if the path points directly at a file, then
normcase would not be called on path.
This would change the expected lower case drive path, on windows, to be
uppercase. This patch simply calls normcase on the test path at the earliest
point possible to avoid this issue.
Reviewers: djtodoro, jmorse
Differential Revision: https://reviews.llvm.org/D78633
Summary:
It is possible that CMake tries to process debuginfo-tests before any
attempt to find Python3. Ensure that CMake attempts to find it before
complaining that it doesn't exist.
Reviewers: zturner, rnk, jmorse, chandlerc
Reviewed By: rnk
Subscribers: mgorny, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79795
The documentation says we need python >= 3.6. Running it with an older
version, we get verbose output from python interpreter.
This patch fixes that as:
$ python2 dexter.py list-debuggers
You need python 3.6 or later to run DExTer
Differential Revision: https://reviews.llvm.org/D78621
OCHyams