Summary:
Unify the code for requiring a complete type and move it into a single
place. The only functional change is that the "cannot start a definition
of an incomplete type" is upgrated from a runtime error/warning to an
lldbassert. An plain assert might also be fine, since (AFAICT) this can
only happen in case of a programmer error.
Reviewers: teemperor, aprantl, shafik
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D83199
With -flimit-debug-info, we can have a definition of a class, but no
definition for some of its members. This extends the same logic we were
using for incomplete base classes to cover incomplete members too.
Test forward-declarations.s is removed as it is no longer applicable --
we don't warn anymore when encountering incomplete members as they could
be completed elsewhere. New checks added to TestLimitDebugInfo cover the
handling of incomplete members more thoroughly.
Summary:
This patch adds support for evaluation of expressions referring to types
which were compiled in -flimit-debug-info (a.k.a -fno-standalone-debug)
in clang. In this mode it's possible that the debug information needed
to fully describe a c++ type is not present in a single shared library
-- for example debug info for a base class or a member of a type can
only be found in another shared library. This situation is not
currently handled well within lldb as we are limited to searching within
a single shared library (lldb_private::Module) when searching for the
definition of these types.
The way that this patch gets around this limitation is by doing the
search at a later stage -- during the construction of the expression ast
context. This works by having the parser (currently SymbolFileDWARF, but
a similar approach is probably needed for PDBs too) mark a type as
"forcefully completed". What this means is that the parser has marked
the type as "complete" in the module ast context (as this is necessary
to e.g. derive classes from it), but its definition is not really there.
This is done via a new field on the ClangASTMetadata struct.
Later, when we are importing such a type into the expression ast, we
check this flag. If the flag is set, we try to find a better definition
for the type in other shared libraries. We do this by initiating a
new lookup for the "forcefully completed" classes, which then imports the
type from a module with a full definition.
This patch only implements this handling for base classes, but other
cases (members, array element types, etc.). The changes for that should
be fairly simple and mostly revolve around marking these types as
"forcefully completed" at an approriate time -- the importing logic is
generic already.
Another aspect, which is also not handled by this patch is viewing these
types via the "frame variable" command. This does not use the AST
importer and so it will need to handle these types on its own -- that
will be the subject of another patch.
Differential Revision: https://reviews.llvm.org/D81561
Summary:
When evaluating an expression referencing a constexpr static member variable, an
error is issued because the PDB does not specify a symbol with an address that
can be relocated against.
Rather than attempt to resolve the variable's value within the IR execution, the
values of all constants can be looked up and incorporated into the AST of the
record type as a literal, mirroring the original compiler AST.
This change applies to DIA and native PDB loaders.
Patch By: jackoalan
Reviewers: aleksandr.urakov, jasonmolenda, zturner, jdoerfert, teemperor
Reviewed By: aleksandr.urakov
Subscribers: sstefan1, lldb-commits, llvm-commits, #lldb
Tags: #lldb, #llvm
Differential Revision: https://reviews.llvm.org/D82160
Prior to my patch of using the LLVM line table parsing code,
SymbolFileDWARF::ParseSupportFiles would only parse the line table
prologues to get the file list for any files that could be in the line
table.
With the old behavior, if we found the file that someone is setting the
breakpoint in in the support files list, we would get a valid index. If
we didn't, we would not look any further. So someone sets a breakpoint
one "MyFile.cpp:12" and if we find "MyFile.cpp" in the support file list
for the compile unit, then and only then would we get the entire line
table for that compile unit.
With the current behavior, no matter what, we always fully parse the
line table for all compile units any time any file and line breakpoint
is set. This creates a serious problem when debugging a large DWARF in
.o file project.
This patch re-instates the old behavior. Unfortunately it means we might
end up parsing to prologue twice, but I don't think that outweighs the
cost of trying to cache/reuse it.
Differential revision: https://reviews.llvm.org/D81589
D80519 <https://reviews.llvm.org/D80519>
added support for `DW_TAG_GNU_call_site` but
Bug 45886 <https://bugs.llvm.org/show_bug.cgi?id=45886>
found one case did not work.
There is:
0x000000b1: DW_TAG_GNU_call_site
DW_AT_low_pc (0x000000000040111e)
DW_AT_abstract_origin (0x000000cc "a")
...
0x000000cc: DW_TAG_subprogram
DW_AT_name ("a")
DW_AT_prototyped (true)
DW_AT_low_pc (0x0000000000401109)
^^^^^^^^^^^^ - here it did overwrite the 'low_pc' variable containing value 0x40111e we wanted
DW_AT_high_pc (0x0000000000401114)
DW_AT_frame_base (DW_OP_call_frame_cfa)
DW_AT_GNU_all_call_sites (true)
DW_TAG_GNU_call_site attributes order as produced by GCC:
0x000000b1: DW_TAG_GNU_call_site
DW_AT_low_pc (0x000000000040111e)
DW_AT_abstract_origin (0x000000cc "a")
clang produces the attributes in opposite order:
0x00000064: DW_TAG_GNU_call_site
DW_AT_abstract_origin (0x0000002a "a")
DW_AT_low_pc (0x0000000000401146)
Differential Revision: https://reviews.llvm.org/D81334
Summary:
The way that the support for the GNU dialect of tail call frames was
implemented in D80519 meant that the were reporting very bogus PC values
which pointed into the middle of an instruction: the -1 trick is
necessary for the address to resolve to the right function, but we
should still be reporting a more realistic PC value -- I say "realistic"
and not "real", because it's very debatable what should be the correct
PC value for frames like this.
This patch achieves that my moving the -1 from SymbolFileDWARF into the
stack frame computation code. The idea is that SymbolFileDWARF will
merely report whether it has provided an address of the instruction
after the tail call, or the address of the call instruction itself. The
StackFrameList machinery uses this information to set the "behaves like
frame zero" property of the artificial frames (the main thing this flag
does is it controls the -1 subtraction when looking up the function
address).
This required a moderate refactor of the CallEdge class, because it was
implicitly assuming that edges pointing after the call were real calls
and those pointing the the call insn were tail calls. The class now
carries this information explicitly -- it carries three mostly
independent pieces of information:
- an address of interest in the caller
- a bit saying whether this address points to the call insn or after it
- whether this is a tail call
Reviewers: vsk, dblaikie
Subscribers: aprantl, mgrang, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D81010
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.
For Swift LLDB (but potentially also for module support in Clang-land)
we need a way to accumulate the path remappings produced by
Module::RegisterXcodeSDK(). In order to make this work for
SymbolFileDebugMaps, registering the search path remapping with both
modules is necessary.
Differential Revision: https://reviews.llvm.org/D79384
<rdar://problem/62750529>
When debugging from a SymbolMap the creation of CompileUnits for the
individual object files is so lazy that RegisterXcodeSDK() is not
invoked at all before the Swift TypeSystem wants to read it. This
patch fixes this by introducing an explicit
SymbolFile::ParseXcodeSDK() call that can be invoked deterministically
before the result is required.
<rdar://problem/62532151+62326862>
https://reviews.llvm.org/D79273
The dumping code is not used by anyone, and is a source of
inconsistencies with the llvm dwarf parser, as dumping is implemented at
a different level (DWARFDie) there.
The cause of this crash is relatively simple -- we are using a
SymbolFileDWARFDwo to parse a (skeleton) dwarf unit. This cause the
CompileUnit to be created with the wrong ID, which later triggers an
assertion in SymbolFile::SetCompileUnitAtIndex. The fix is also simple
-- ensure we use the right symbol file for parsing.
However, a fairly elaborate setup is needed trigger this bug, because
ParseCompileUnit is normally called very early on (and with the right
symbol file object) during the process of accessing a compile unit.
The only way this can be triggered is if the DWARF unit is
"accidentally" pulled into scope during expression evaluation
This can happen if the "this" object used for the context of an
expression is in a namespace, and that namespace is also present in
other compile units
The included test recreates this setup.
Summary:
The code in DWARFCompileUnit::BuildAddressRangeTable tries hard to avoid
relying on DW_AT_low/high_pc for compile unit range information, and
this logic is a big cause of llvm/lldb divergence in the lowest layers
of dwarf parsing code.
The implicit assumption in that code is that this information (as opposed to
DW_AT_ranges) is unreliable. However, I have not been able to verify
that assumption. It is definitely not true for all present-day
compilers (gcc, clang, icc), and it was also not the case for the
historic compilers that I have been able to get a hold of (thanks Matt
Godbolt).
All compiler included in my research either produced correct
DW_AT_ranges or .debug_aranges entries, or they produced no DW_AT_hi/lo
pc at all. The detailed findings are:
- gcc >= 4.4: produces DW_AT_ranges and .debug_aranges
- 4.1 <= gcc < 4.4: no DW_AT_ranges, no DW_AT_high_pc, .debug_aranges
present. The upper version range here is uncertain as godbolt.org does
not have intermediate versions.
- gcc < 4.1: no versions on godbolt.org
- clang >= 3.5: produces DW_AT_ranges, and (optionally) .debug_aranges
- 3.4 <= clang < 3.5: no DW_AT_ranges, no DW_AT_high_pc, .debug_aranges
present.
- clang <= 3.3: no DW_AT_ranges, no DW_AT_high_pc, no .debug_aranges
- icc >= 16.0.1: produces DW_AT_ranges
- icc < 16.0.1: no functional versions on godbolt.org (some are present
but fail to compile)
Based on this analysis, I believe it is safe to start trusting
DW_AT_low/high_pc information in dwarf as well as remove the code for
manually reconstructing range information by traversing the DIE
structure, and just keep the line table fallback. The only compilers
where this will change behavior are pre-3.4 clangs, which are almost 7
years old now. However, the functionality should remain unchanged
because we will be able to reconstruct this information from the line
table, which seems to be needed for some line-tables-only scenarios
anyway (haven't researched this too much, but at least some compilers
seem to emit DW_AT_ranges even in these situations).
In addition, benchmarks showed that for these compilers computing the
ranges via line tables is noticably faster than doing so via the DIE
tree.
Other advantages include simplifying the code base, removing some
untested code (the only test changes are recent tests with overly
reduced synthetic dwarf), and increasing llvm convergence.
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D78489
Pavel Labath wrote in D73206:
The internal representation of DebugNames and Apple indexes is fixed by
the relevant (pseudo-)standards, so we can't really change it. The
question is how to efficiently (and cleanly) convert from the internal
representation to some common thing. The conversion from AppleIndex to
DIERef is trivial (which is not surprising as it was the first and the
overall design was optimized for that). With debug_names, the situation
gets more tricky. The internal representation of debug_names uses
CU-relative DIE offsets, but DIERef wants an absolute offset. That means
the index has to do more work to produce the common representation. And
it needs to do that for all results, even though a lot of the index
users are really interested only in a single entry. With the switch to
user_id_t, _all_ indexes would have to do some extra work to encode it,
only for their users to have to immediately decode it back. Having
a iterator/callback based api would allow us to minimize the impact of
that, as it would only need to happen for the entries that are really
used. And /I think/ we could make it interface returns DWARFDies
directly, and each index converts to that using the most direct approach
available.
Jan Kratochvil:
It also makes all the callers shorter as they no longer need to fetch
DWARFDIE from DIERef (and handling if not found by ReportInvalidDIERef)
but the callers are already served DWARFDIE which they need.
In some cases the DWARFDIE had to be fetched both by callee (DWARFIndex
implementation) and caller.
Differential Revision: https://reviews.llvm.org/D77970
It removes some needless deep indentation and some redundant statements.
It prepares the code for a more clean next patch - DWARF index callbacks
D77327.
Differential Revision: https://reviews.llvm.org/D77326
Types that came from a Clang module are nested in DW_TAG_module tags
in DWARF. This patch recreates the Clang module hierarchy in LLDB and
1;95;0csets the owning module information accordingly. My primary motivation
is to facilitate looking up per-module APINotes for individual
declarations, but this likely also has other applications.
This reapplies the previously reverted commit, but without support for
ClassTemplateSpecializations, which I'm going to look into separately.
rdar://problem/59634380
Differential Revision: https://reviews.llvm.org/D75488
This is mostly useful for Swift support; it allows LLDB to substitute
a matching SDK it shipped with instead of the sysroot path that was
used at compile time.
The goal of this is to make the Xcode SDK something that behaves more
like the compiler's resource directory, as in that it ships with LLDB
rather than with the debugged program. This important primarily for
importing Swift and Clang modules in the expression evaluator, and
getting at the APINotes from the SDK in Swift.
For a cross-debugging scenario, this means you have to have an SDK for
your target installed alongside LLDB. In Xcode this will always be the
case.
rdar://problem/60640017
Differential Revision: https://reviews.llvm.org/D76471
This is a preparation for an upcoming patch which adds support for
DWARFv5 unit index sections. The patch adds tag "_EXT_" to identifiers
which reference sections that are deprecated in the DWARFv5 standard.
See D75929 for the discussion.
Differential Revision: https://reviews.llvm.org/D77141
Apparently the intention was to copy the condition above:
if (types.GetSize() >= max_matches)
break;
So that if the iteration stopped because of too many matches we do not
add even more matches in this 'Clang modules' block downward.
It was implemented by:
SymbolFileDWARF: Unconditionally scan through clang modules. NFCish
fe9eaadd68
Differential Revision: https://reviews.llvm.org/D77336
It is an obvious part of D77326.
It removes some needless deep indentation and some redundant statements.
It prepares the code for a more clean next patch - DWARF index callbacks
in D77327.
The old name was a bit misleading because the functions actually return
contributions to the corresponding sections.
Differential revision: https://reviews.llvm.org/D77302
Types that came from a Clang module are nested in DW_TAG_module tags
in DWARF. This patch recreates the Clang module hierarchy in LLDB and
sets the owning module information accordingly. My primary motivation
is to facilitate looking up per-module APINotes for individual
declarations, but this likely also has other applications.
rdar://problem/59634380
Differential Revision: https://reviews.llvm.org/D75488
When parsing DWARF and laying out bit-fields we currently don't take into account whether we have a base class or not.
Currently if the first field is a bit-field but the bit offset is due a field we inherit from a base class we currently
treat it as an unnamed bit-field and therefore add an extra field.
This fix will not check if we have a base class and assume that this offset is due to members we are inheriting from the base.
We are currently seeing asserts during codegen when debugging clang::DiagnosticOptions.
This assumption will fail in the case where the first field in the derived class in an unnamed bit-field. Fixing the first field
being an unnamed bit-field looks like it will require a larger change since we will need a way to track or discover the last field offset of the bases(s).
Differential Revision: https://reviews.llvm.org/D76808
In breakpad, only x86 (and mips) registers have a leading '$' in their
names. Arm architectures use plain register names.
Previously, lldb was assuming all registers have a '$'. Fix the code to
match the (unfortunately, inconsistent) reality.
Reland with changes: the test modified in this change originally failed
on a Debian/x86_64 builder, and I suspect the cause was that lldb looked
up the line location for an artificial frame by subtracting 1 from the
frame's address. For artificial frames, the subtraction must not happen
because the address is already exact.
---
lldb currently guesses the address to use when creating an artificial
frame (i.e., a frame constructed by determining the sequence of (tail)
calls which must have happened).
Guessing the address creates problems -- use the actual address provided
by the DW_AT_call_pc attribute instead.
Depends on D76336.
rdar://60307600
Differential Revision: https://reviews.llvm.org/D76337
This reverts commit 6905394d15. The
changed test is failing on Debian/x86_64, possibly because lldb is
subtracting an offset from the DW_AT_call_pc address used for the
artificial frame:
http://lab.llvm.org:8011/builders/lldb-x86_64-debian/builds/7171/steps/test/logs/stdio
/home/worker/lldb-x86_64-debian/lldb-x86_64-debian/llvm-project/lldb/test/API/functionalities/tail_call_frames/unambiguous_sequence/main.cpp:6:17: error: CHECK-NEXT: expected string not found in input
// CHECK-NEXT: frame #1: 0x{{[0-9a-f]+}} a.out`func3() at main.cpp:14:3 [opt] [artificial]
^
<stdin>:3:2: note: scanning from here
frame #1: 0x0000000000401127 a.out`func3() at main.cpp:13:4 [opt] [artificial]
lldb currently guesses the address to use when creating an artificial
frame (i.e., a frame constructed by determining the sequence of (tail)
calls which must have happened).
Guessing the address creates problems -- use the actual address provided
by the DW_AT_call_pc attribute instead.
Depends on D76336.
rdar://60307600
Differential Revision: https://reviews.llvm.org/D76337
Fix to get the AST we generate for function templates closer to what clang generates and expects.
We fix which FuntionDecl we are passing to CreateFunctionTemplateSpecializationInfo and we strip
template parameters from the name when creating the FunctionDecl and FunctionTemplateDecl.
These two fixes together fix asserts and ambiguous lookup issues for several cases which are added to the already existing small function template test.
This fixes issues with overloads, overloads and ADL, variadic function templates and templated operator overloads.
Differential Revision: https://reviews.llvm.org/D75761
