The C headers are deprecated so as requested in D102845, this is replacing them
all with their (not deprecated) C++ equivalent.
Reviewed By: shafik
Differential Revision: https://reviews.llvm.org/D103084
DWARFExpression implements the DWARF2 expression model that left
ambiguity on whether the result of an expression was a value or an
address. This patch implements the DWARF location description model
introduces in DWARF 4 and sets the result Value's kind accordingly, if
the expression comes from a DWARF v4+ compile unit. The nomenclature
is taken from DWARF 5, chapter 2.6 "Location Descriptions".
Differential Revision: https://reviews.llvm.org/D98996
This is a follow-up to 188b0747c1. This
is a very narrow fix to a more general problem. LLDB should be better
at distinguishing between implict and memory location descriptions.
rdar://74902042
Swift async functions receive function arguments inside a
heap-allocated data structure, similar to how ObjC block captures or
C++ coroutine arguments are implement. In DWARF they are described
relative to an entry value that produces a pointer into that heap
object. At typical location looks like
DW_OP_entry_value [ DW_OP_reg14 ] DW_OP_deref DW_OP_plus_uconst 32 DW_OP_deref
This allows the unwinder (which has special ABI knowledge to restore
the contents of r14) to push the base address onto the stack thus
allowing the deref/offset operations to continue. The result of the
entry value is a scalar, because DW_OP_reg14 is a register location —
as it should be since we want to restore the pointer value contained
in r14 at the beginning of the function and not the historical memory
contents it was pointing to. The entry value should restore the
address, which is still valid, not the contents at function entry.
To make this work, we need to allow LLDB to dereference Scalar stack
results like load addresses, which is what this patch
does. Unfortunately it is difficult to test this in isolation, since
the DWARFExpression unit test doesn't have a process.
Differential Revision: https://reviews.llvm.org/D96549
The comment for ValueType claims that all values <1 are errors, but
not all switch statements take this into account. This patch
introduces an explicit Error case and deletes all default: cases, so
we get warned about incomplete switch coverage.
https://reviews.llvm.org/D96537
Dwarf says (Section 2.5.1.1. of DWARF v5) that these operations should
push "generic" (pointer-sized) values. This was not the case for
DW_OP_const operations (which were pushing values based on the size of
arguments), nor DW_OP_litN (which were always pushing 64-bit values).
The practical effect of this that were were unable to display the values
of variables if the size of the DW_OP_const opcode was smaller than the
value of the variable it was describing. This would happen because we
would store this (small) result into a buffer and then would not be able
to read sufficient data out of it (in Value::GetValueAsData). Gcc emits
debug info like this.
Other (more subtle) effects are also possible.
The same fix should be applied to DW_OP_const[us] (leb128 versions), but
I'm not doing that right now, because that would cause us to display
wrong (truncated) values of variables on 32-bit targets (pr48087).
Differential Revision: https://reviews.llvm.org/D90840
This class and it's surroundings contain a lot of shady code, but as far
as I can tell all of that code is unreachable (there is no code actually
setting the value to eValueTypeVector).
According to history this class was introduced in 2012 in
r167033/0665a0f09. At that time, the code seemed to serve some purpose,
and it had two entry points (in Value::SetContext and
ClangExpressionDeclMap::LookupDecl). The first entry point was deleted
in D17897 and the second one in r179842/44342735.
The stated purpose of the patch introducing this class was to fix
TestRegisters.py, and "expr $xmm0" in particular. Both of these things
function perfectly well these days without this class.
This patch completes https://reviews.llvm.org/D83560. Now that the
compiler can emit `DW_OP_implicit_value` into DWARF expressions, lldb
needed to learn reading these opcodes for variable inspection and
expression evaluation.
This implicit location descriptor specifies an immediate value with two
operands: the length (ULEB128) followed by a block representing the value
in the target memory representation.
rdar://67406091
Differential revision: https://reviews.llvm.org/D89842
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
The "type" argument to the function is mostly useless -- the only
interesting aspect of it is signedness. Pass signedness directly and
compute the value of bits and signedness fields -- that's exactly
what the single caller of this function does.
Previously, we were simply ignoring them and continuing the evaluation.
This behavior does not seem useful, because the resulting value will
most likely be completely bogus.
Summary:
The code changes are very straight-forward -- just handle both DW_AT_GNU
and DW_AT_call versions of all tags and attributes. There is just one
small gotcha: in the GNU version, DW_AT_low_pc was used both for the
"return pc" and the "call pc" values, depending on whether the tag was
describing a tail call, while the official scheme uses different
attributes for the two things.
Reviewers: vsk, dblaikie
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D80519
The llvm DWARFExpression dump is nearly identical, but better -- for
example it does print a spurious space after zero-argument expressions.
Some parts of our code (variable locations) have been already switched
to llvm-based expression dumping. This switches the remainder: unwind
plans and some unit tests.
Originally committed as 416fa7720e
Reverted (due to buildbot failure - breaking lldb) in 7a45aeacf3.
I still can't seem to build lldb locally, but Pavel Labath has kindly
provided a potential fix to preserve the old behavior in lldb by
registering a simple recoverable error handler there that prints to the
desired stream in lldb, rather than stderr.
This patch fixes a crash that happens on the DWARF expression evaluator
when trying to access the top of the stack while it's empty.
rdar://60512489
Differential Revision: https://reviews.llvm.org/D77108
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
This patch fixes a crash that happens on the DWARF expression evaluator
when trying to access the top of the stack while it's empty.
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
Summary:
A *.cpp file header in LLDB (and in LLDB) should like this:
```
//===-- TestUtilities.cpp -------------------------------------------------===//
```
However in LLDB most of our source files have arbitrary changes to this format and
these changes are spreading through LLDB as folks usually just use the existing
source files as templates for their new files (most notably the unnecessary
editor language indicator `-*- C++ -*-` is spreading and in every review
someone is pointing out that this is wrong, resulting in people pointing out that this
is done in the same way in other files).
This patch removes most of these inconsistencies including the editor language indicators,
all the different missing/additional '-' characters, files that center the file name, missing
trailing `===//` (mostly caused by clang-format breaking the line).
Reviewers: aprantl, espindola, jfb, shafik, JDevlieghere
Reviewed By: JDevlieghere
Subscribers: dexonsmith, wuzish, emaste, sdardis, nemanjai, kbarton, MaskRay, atanasyan, arphaman, jfb, abidh, jsji, JDevlieghere, usaxena95, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D73258
and document the shortcomings of LLDB's partially defined DW_OP_piece
handling.
This would manifest as "DW_OP_piece for offset foo but top of stack is
of size bar".
rdar://problem/46262998
Differential Revision: https://reviews.llvm.org/D72880
By switching to Scalars that are backed by explicitly-sized APInts we
can avoid a bug that increases the buffer reserved for a small piece
to the next-largest host integer type.
This manifests as "DW_OP_piece for offset foo but top of stack is of size bar".
Differential Revision: https://reviews.llvm.org/D72879
Summary:
Our code was expecting that a single (symbol) file contains only one
kind of location lists. This is not correct (on non-apple platforms, at
least) as a file can compile units with different dwarf versions.
This patch moves the deteremination of location list flavour down to the
compile unit level, fixing this problem. I have also tried to rougly
align the code with the llvm DWARFUnit. Fully matching the API is not
possible because of how lldb's DWARFExpression lives separately from the
rest of the DWARF code, but this is at least a step in the right
direction.
Reviewers: JDevlieghere, aprantl, clayborg
Subscribers: dblaikie, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D71751
Summary:
This patch deletes the lldb location list parser and teaches the
DWARFExpression class to use the parser in llvm instead. I have
centralized all the places doing the parsing into a single
GetLocationExpression function.
In theory the the actual location list parsing should be covered by llvm
tests, and this glue code by our existing location list tests, but since
we don't have that many location list tests, I've tried to extend the
coverage a bit by adding some explicit dwarf5 loclist handling and a
test of the dumping code.
For DWARF4 location lists this should be NFC (modulo small differences
in error handling which should only show up on invalid inputs). In case
of DWARF5, this fixes various missing bits of functionality, most
notably, the lack of support for DW_LLE_offset_pair.
Reviewers: JDevlieghere, aprantl, clayborg
Subscribers: lldb-commits, dblaikie
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D71003
Summary:
Lldb support base address selection entries in location lists was broken
for a long time. This wasn't noticed until llvm started producing these
kinds of entries more frequently with r374600.
In r374769, I made a quick patch which added sufficient support for them
to get the test suite to pass. However, I did not fully understand how
this code operates, and so the fix was not complete. Specifically, what
was lacking was the ability to handle modules which were not loaded at
their preferred load address (for instance, due to ASLR).
Now that I better understand how this code works, I've come to the
conclusion that the current setup does not provide enough information
to correctly process these entries. In the current setup the location
lists were parameterized by two addresses:
- the distance of the function start from the start of the compile unit.
The purpose of this was to make the location ranges relative to the
start of the function.
- the actual address where the function was loaded at. With this the
function-start-relative ranges can be translated to actual memory
locations.
The reason for the two values, instead of just one (the load bias) is (I
think) MachO, where the debug info in the object files will appear to be
relative to the address zero, but the actual code it refers to
can be moved and reordered by the linker. This means that the location
lists need to be "linked" to reflect the locations in the actual linked
file.
These two bits of information were enough to correctly process location
lists which do not contain base address selection entries (and so all
entries are relative to the CU base). However, they don't work with
them because, in theory two base address can be completely unrelated (as
can happen for instace with hot/cold function splitting, where the
linker can reorder the two pars arbitrarily).
To fix that, I split the first parameter into two:
- the compile unit base address
- the function start address, as is known in the object file
The new algorithm becomes:
- the location lists are processed as they were meant to be processed.
The CU base address is used as the initial base address value. Base
address selection entries can set a new base.
- the difference between the "file" and "load" function start addresses
is used to compute the load bias. This value is added to the final
ranges to get the actual memory location.
This algorithm is correct for non-MachO debug info, as there the
location lists correctly describe the code in the final executable, and
the dynamic linker can just move the entire module, not pieces of it. It
will also be correct for MachO if the static linker preserves relative
positions of the various parts of the location lists -- I don't know
whether it actually does that, but judging by the lack of base address
selection support in dsymutil and lldb, this isn't something that has
come up in the past.
I add a test case which simulates the ASLR scenario and demonstrates
that base address selection entries now work correctly here.
Reviewers: JDevlieghere, aprantl, clayborg
Subscribers: dblaikie, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70532
Summary:
Yet another step on the long road towards getting rid of lldb's Stream class.
We probably should just make this some kind of member of Address/AddressRange, but it seems quite often we just push
in random integers in there and this is just about getting rid of Stream and not improving arbitrary APIs.
I had to rename another `DumpAddress` function in FormatEntity that is dumping the content of an address to make Clang happy.
Reviewers: labath
Reviewed By: labath
Subscribers: JDevlieghere, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D71052
Summary:
I recently re-discovered that the unsinged stream operators of the
lldb_private::Stream class have a surprising behavior in that they print
the number in hex. This is all the more confusing because the "signed"
versions of those operators behave normally.
Now that, thanks to Raphael, each Stream class has a llvm::raw_ostream
wrapper, I think we should delete most of our formatting capabilities
and just delegate to that. This patch tests the water by just deleting
the operators with the most surprising behavior.
Most of the code using these operators was printing user_id_t values. It
wasn't fully consistent about prefixing them with "0x", but I've tried
to consistenly print it without that prefix, to make it more obviously
different from pointer values.
Reviewers: teemperor, JDevlieghere, jdoerfert
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70241
Split CallEdge into DirectCallEdge and IndirectCallEdge. Teach
DWARFExpression how to evaluate entry values in cases where the current
activation was created by an indirect call.
rdar://57094085
Differential Revision: https://reviews.llvm.org/D70100
The DWARFExpression is parsing the location lists in about five places.
Of those, only one actually had proper support for base address
selection entries.
Since r374600, llvm has started to produce location expressions with
base address selection entries more aggresively, which caused some tests
to fail.
This patch adds support for these entries to the places which had it
missing, fixing the failing tests. It also adds a targeted test for the
two of the three fixes, which should continue testing this functionality
even if the llvm output changes. I am not aware of a way to write a
targeted test for the third fix (DWARFExpression::Evaluate).
llvm-svn: 374769
Summary:
It uses the new ability of ABI plugins to vend llvm::MCRegisterInfo
structs (which is what is needed to turn dwarf register numbers into
strings).
Reviewers: JDevlieghere, aprantl, jasonmolenda
Subscribers: tatyana-krasnukha, lldb-commits
Differential Revision: https://reviews.llvm.org/D67966
llvm-svn: 373208
Add support for evaluating DW_OP_entry_value. This involves parsing
DW_TAG_call_site_parameter and wiring the information through to the expression
evaluator.
rdar://54496008
Differential Revision: https://reviews.llvm.org/D67376
llvm-svn: 371668
This patch adds basic support for DW_OP_convert[1] for integer
types. Recent versions of LLVM's optimizer may insert this opcode into
DWARF expressions. DW_OP_convert is effectively a type cast operation
that takes a reference to a base type DIE (or zero) and then casts the
value at the top of the DWARF stack to that type. Internally this
works by changing the bit size of the APInt that is used as backing
storage for LLDB's DWARF stack.
I managed to write a unit test for this by implementing a mock YAML
object file / module that takes debug info sections in yaml2obj
format.
[1] Typed DWARF stack. http://www.dwarfstd.org/ShowIssue.php?issue=140425.1
<rdar://problem/48167864>
Differential Revision: https://reviews.llvm.org/D67369
llvm-svn: 371532
Summary:
The only reason for this function's existance is so that we could pass
the correct size into the DWARFExpression constructor. However, there is
no harm in passing the entire data extractor into the DWARFExpression,
since the same code is performing the size determination as well as the
subsequent parse. So, if we get malformed input or there's a bug in the
parser, we'd compute the wrong size anyway.
Additionally, reducing the number of entry points into the location list
parsing machinery makes it easier to switch the llvm debug_loc(lists)
parsers.
While inside, I added a couple of tests for invalid location list
handling.
Reviewers: JDevlieghere, clayborg
Subscribers: aprantl, javed.absar, kristof.beyls, lldb-commits
Differential Revision: https://reviews.llvm.org/D66789
llvm-svn: 370373
Summary:
The DWARFExpression methods have a lot of arguments. This removes two of
them by removing the ability to slice the expression via two offset+size
parameters. This is a functionality that it is not always needed, and
when it is, we already have a different handy way of slicing a data
extractor which we can use instead.
Reviewers: JDevlieghere, clayborg
Subscribers: aprantl, lldb-commits
Differential Revision: https://reviews.llvm.org/D66745
llvm-svn: 370027
This patch replaces explicit calls to log::Printf with the new LLDB_LOGF
macro. The macro is similar to LLDB_LOG but supports printf-style format
strings, instead of formatv-style format strings.
So instead of writing:
if (log)
log->Printf("%s\n", str);
You'd write:
LLDB_LOG(log, "%s\n", str);
This change was done mechanically with the command below. I replaced the
spurious if-checks with vim, since I know how to do multi-line
replacements with it.
find . -type f -name '*.cpp' -exec \
sed -i '' -E 's/log->Printf\(/LLDB_LOGF\(log, /g' "{}" +
Differential revision: https://reviews.llvm.org/D65128
llvm-svn: 366936
Previously it was storing a *pointer*, which left open the possibility
of this pointer being null. We never made use of that possibility (it
does not make sense), and most of the code was already assuming that.
However, there were a couple of null-checks scattered around the code.
This patch replaces the reference with a pointer, making the
non-null-ness explicit, and removes the remaining null-checks.
llvm-svn: 363381
Like many of our DWARF classes, the DWARFExpression can be initialized
in several ways. One such way was through a constructor that takes just
the compile unit. This constructor is used to initialize both empty
DWARFExpressions, and DWARFExpression that will be populated later.
To make the distinction more clear, I changed the constructor to a
default constructor and updated its call sites. Where the
DWARFExpression was being populated later, I replaced that with a call
to the copy assignment constructor.
Differential revision: https://reviews.llvm.org/D62425
llvm-svn: 361849
Summary:
NFC = [[ https://llvm.org/docs/Lexicon.html#nfc | Non functional change ]]
This commit is the result of modernizing the LLDB codebase by using
`nullptr` instread of `0` or `NULL`. See
https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-nullptr.html
for more information.
This is the command I ran and I to fix and format the code base:
```
run-clang-tidy.py \
-header-filter='.*' \
-checks='-*,modernize-use-nullptr' \
-fix ~/dev/llvm-project/lldb/.* \
-format \
-style LLVM \
-p ~/llvm-builds/debug-ninja-gcc
```
NOTE: There were also changes to `llvm/utils/unittest` but I did not
include them because I felt that maybe this library shall be updated in
isolation somehow.
NOTE: I know this is a rather large commit but it is a nobrainer in most
parts.
Reviewers: martong, espindola, shafik, #lldb, JDevlieghere
Reviewed By: JDevlieghere
Subscribers: arsenm, jvesely, nhaehnle, hiraditya, JDevlieghere, teemperor, rnkovacs, emaste, kubamracek, nemanjai, ki.stfu, javed.absar, arichardson, kbarton, jrtc27, MaskRay, atanasyan, dexonsmith, arphaman, jfb, jsji, jdoerfert, lldb-commits, llvm-commits
Tags: #lldb, #llvm
Differential Revision: https://reviews.llvm.org/D61847
llvm-svn: 361484
Summary:
The DWARF spec states that the DWARF stack arguments are numbered from
the top. Our implementation of DW_OP_pick was counting them from the
bottom.
This bug probably wasn't noticed because nobody (except my upcoming
postfix-to-DWARF converter) uses DW_OP_pick, but I've cross-checked with
gdb to confirm that counting from the top is the expected behavior.
This patch fixes the implementation to match the spec and gdb behavior
and adds a test.
Reviewers: jasonmolenda, clayborg
Subscribers: mgorny, aprantl, lldb-commits
Differential Revision: https://reviews.llvm.org/D61182
llvm-svn: 359436
A lot of comments in LLDB are surrounded by an ASCII line to delimit the
begging and end of the comment.
Its use is not really consistent across the code base, sometimes the
lines are longer, sometimes they are shorter and sometimes they are
omitted. Furthermore, it looks kind of weird with the 80 column limit,
where the comment actually extends past the line, but not by much.
Furthermore, when /// is used for Doxygen comments, it looks
particularly odd. And when // is used, it incorrectly gives the
impression that it's actually a Doxygen comment.
I assume these lines were added to improve distinguishing between
comments and code. However, given that todays editors and IDEs do a
great job at highlighting comments, I think it's worth to drop this for
the sake of consistency. The alternative is fixing all the
inconsistencies, which would create a lot more churn.
Differential revision: https://reviews.llvm.org/D60508
llvm-svn: 358135
Summary: DW_OP_GNU_addr_index has been renamed as DW_OP_addrx in the standard. clang produces DW_OP_addrx tags and with this change lldb starts to process them.
Reviewers: aprantl, jingham, davide, clayborg, serge-sans-paille
Reviewed By: aprantl
Subscribers: jdoerfert, dblaikie, labath, shafik, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D59004
llvm-svn: 355629
Raphael Isemann