Commit Graph

745 Commits

Author SHA1 Message Date
Jonas Devlieghere fd2433e139 [lldb] Replace default bodies of special member functions with = default;
Replace default bodies of special member functions with = default;

$ run-clang-tidy.py -header-filter='lldb' -checks='-*,modernize-use-equals-default' -fix ,

https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-equals-default.html

Differential revision: https://reviews.llvm.org/D104041
2021-07-02 11:31:16 -07:00
Adrian Prantl a0e1b11fac Modernize Module::RemapFile to return an Optional (NFC)
This addresses feedback raised in https://reviews.llvm.org/D104404.

Differential Revision: https://reviews.llvm.org/D104724
2021-06-29 15:19:31 -07:00
Adrian Prantl 42e2a90684 Relax language comparison when matching up C++ forward decls with definitions
when dealing with -gmodules debug info.

This fixes the bot failures on Darwin.

A recent clang change (presumably https://reviews.llvm.org/D104291)
introduced a bug where .pcm files would identify themselves as
DW_LANG_C_plus_plus, but the .o that references them would identify as
DW_LANG_C_plus_plus_14. While that bug needs to be fixed, too, it
shows that the current strict comparison also isn't meaningful.

rdar://79423225
2021-06-16 18:21:43 -07:00
Raphael Isemann 0a655c62ec [lldb][NFC] Remove a redundant call to weak_ptr::expired
The `lock` call directly will check for us if the `weak_ptr` is expired and
returns an invalid `shared_ptr` (which we correctly handle), so this check is
redundant.

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D103442
2021-06-04 12:06:53 +02:00
Raphael Isemann 76e47d4887 [lldb][NFC] Use C++ versions of the deprecated C standard library headers
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
2021-05-26 12:46:12 +02:00
Med Ismail Bennani 3e2ed74405 [lldb] Refactor argument group by SourceLocationSpec (NFCI)
This patch refactors a good part of the code base turning the usual
FileSpec, Line, Column, CheckInlines, ExactMatch arguments into a
SourceLocationSpec object.

This change is required for a following patch that will add handling of the
column line information when doing symbol resolution.

Differential Revision: https://reviews.llvm.org/D100965

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2021-05-04 23:04:31 +00:00
Caroline Tice 3dc24bc31e [LLDB] Re-land: Use path relative to binary for finding .dwo files.
DWARF allows .dwo file paths to be relative rather than absolute. When
they are relative, DWARF uses DW_AT_comp_dir to find the .dwo
file. DW_AT_comp_dir can also be relative, making the entire search
patch for the .dwo file relative. In this case, LLDB currently
searches relative to its current working directory, i.e. the directory
from which the debugger was launched. This is not right, as the
compiler, which generated the relative paths, can have no idea where
the debugger will be launched. The correct thing is to search relative
to the location of the executable binary. That is what this patch
does.

Differential Revision: https://reviews.llvm.org/D97786
2021-04-16 11:12:39 -07:00
Caroline Tice 042668d092 Revert "[LLDB] Use path relative to binary for finding .dwo files."
This reverts commit b241f3cb29.

Test case is breaking windows builder.
2021-04-15 17:17:44 -07:00
Caroline Tice b241f3cb29 [LLDB] Use path relative to binary for finding .dwo files.
DWARF allows .dwo file paths to be relative rather than absolute. When
they are relative, DWARF uses DW_AT_comp_dir to find the .dwo
file. DW_AT_comp_dir can also be relative, making the entire search
patch for the .dwo file relative. In this case, LLDB currently
searches relative to its current working directory, i.e. the directory
from which the debugger was launched. This is not right, as the
compiler, which generated the relative paths, can have no idea where
the debugger will be launched. The correct thing is to search relative
to the location of the executable binary. That is what this patch
does.

Differential Revision: https://reviews.llvm.org/D97786
2021-04-15 14:43:47 -07:00
Greg Clayton eee309068e Fix .debug_aranges parsing issues.
When LLVM error handling was introduced to the parsing of the .debug_aranges it would cause major issues if any DWARFDebugArangeSet::extract() calls returned any errors. The code in DWARFDebugInfo::GetCompileUnitAranges() would end up calling DWARFDebugAranges::extract() which would return an error if _any_ DWARFDebugArangeSet had any errors, but it default constructed a DWARFDebugAranges object into DWARFDebugInfo::m_cu_aranges_up and populated it partially, and returned an error prior to finishing much needed functionality in the DWARFDebugInfo::GetCompileUnitAranges() function. Subsequent callers to this function would see that the DWARFDebugInfo::m_cu_aranges_up was actually valid and return this partially populated DWARFDebugAranges reference _and_ it would not be sorted or minimized.

This above bugs would cause an incomplete .debug_aranges parsing, it would skip manually parsing any compile units for ranges, and would not sort the DWARFDebugAranges in m_cu_aranges_up.

This bug would also cause breakpoints set by file and line to fail to set correctly if a symbol context for an address could not be resolved properly, which the incomplete and unsorted DWARFDebugAranges object that DWARFDebugInfo::GetCompileUnitAranges() returned would cause symbol context lookups resolved by address (breakpoint address) to fail to find any DWARF debug info for a given address.

This patch fixes all of the issues that I found:
- DWARFDebugInfo::GetCompileUnitAranges() no longer returns a "llvm::Expected<DWARFDebugAranges &>", but just returns a "const DWARFDebugAranges &". Why? Because this code contained a fallback that would parse all of the valid DWARFDebugArangeSet objects, and would check which compile units had valid .debug_aranges set entries, and manually build an address ranges table using DWARFUnit::BuildAddressRangeTable(). If we return an error because any DWARFDebugArangeSet has any errors, then we don't do any of this code. Now we parse all DWARFDebugArangeSet objects that have no errors, if any calls to DWARFDebugArangeSet::extract() return errors, we skip that DWARFDebugArangeSet so that we can use the fallback call to DWARFUnit::BuildAddressRangeTable(). Since DWARFDebugInfo::GetCompileUnitAranges() needs to parse what it can from the .debug_aranges and build address ranges tables for any compile units that don't have any .debug_aranges sets, everything now works as expected.
- Fix an issue where a DWARFDebugArangeSet contains multiple terminator entries. The LLVM parser and llvm-dwarfdump properly warn about this because it happens with linux compilers and linkers and was the original cause of the bug I am fixing here. We now correctly warn about this issue if "log enable dwarf info" is enabled, but we continue to parse the DWARFDebugArangeSet correctly so we don't lose data that is contained in the .debug_aranges section.
- DWARFDebugAranges::extract() no longer returns a llvm::Error because we need to be able to parse all of the valid DWARFDebugArangeSet objects. It also will correctly skip a DWARFDebugArangeSet object that has errors in the middle of the stream by setting the start offsets of each DWARFDebugArangeSet to be calculated by the previous DWARFDebugArangeSet::extract() calculated offset that uses the header which contains the length of the DWARFDebugArangeSet. This means if do we run into real errors while parsing individual DWARFDebugArangeSet objects, we can continue to parse the rest of the validly encoded DWARFDebugArangeSet objects in the .debug_aranges section. This will allow LLDB to parse DWARF that contains a possibly newer .debug_aranges set format than LLDB currently supports because we will error out for the parsing of the DWARFDebugArangeSet, but be able to skip to the next DWARFDebugArangeSet object using the "DWARFDebugArangeSet.m_header.length" field to calculate the next starting offset.

Tests were added to cover all new functionality.

Differential Revision: https://reviews.llvm.org/D99401
2021-03-29 15:34:36 -07:00
Greg Clayton e122877f10 Add a progress class that can track long running operations in LLDB.
LLDB can often appear deadlocked to users that use IDEs when it is indexing DWARF, or parsing symbol tables. These long running operations can make a debug session appear to be doing nothing even though a lot of work is going on inside LLDB. This patch adds a public API to allow clients to listen to debugger events that report progress and will allow UI to create an activity window or display that can show users what is going on and keep them informed of expensive operations that are going on inside LLDB.

Differential Revision: https://reviews.llvm.org/D97739
2021-03-24 12:58:13 -07:00
Kim-Anh Tran 68dafe40a6 [lldb] Use CompileUnit::ResolveSymbolContext in SymbolFileDWARF
SymbolFileDWARF::ResolveSymbolContext is currently unaware that in DWARF5 the primary file is specified at file index 0. As a result it misses to correctly resolve the symbol context for the primary file when DWARF5 debug data is used and the primary file is only specified at index 0.

This change makes use of CompileUnit::ResolveSymbolContext to resolve the symbol context. The ResolveSymbolContext in CompileUnit has been previously already updated to reflect changes in DWARF5
and contains a more readable version. It can resolve more, but will also do a bit more work than
SymbolFileDWARF::ResolveSymbolContext (getting the Module, and going through SymbolFileDWARF::ResolveSymbolContextForAddress), however, it's mostly directed by $resolve_scope
what will be resolved, and ensures that code is easier to maintain if there's only one path.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D98619
2021-03-22 08:44:16 +01:00
Andy Yankovsky 3b47bd32f9 [lldb] Fix handling of `DW_AT_decl_file` according to D91014 (attempt #2)
Apply changes from https://reviews.llvm.org/D91014 to other places where DWARF entries are being processed.

Test case is provided by @jankratochvil.
The test is marked to run only on x64 and exclude Windows and Darwin, because the assembly is not OS-independent.

(First attempt https://reviews.llvm.org/D96778 broke the build bots)

Reviewed By: jankratochvil

Differential Revision: https://reviews.llvm.org/D97765
2021-03-03 10:27:35 +01:00
Jan Kratochvil 011e7bcaa3 Revert "[lldb] Fix handling of `DW_AT_decl_file` according to D91014"
This reverts commit 7ec7876fed.

Non-x86_64 non-Linux bots broke by the testcase.
2021-03-01 20:45:30 +01:00
Andy Yankovsky 7ec7876fed [lldb] Fix handling of `DW_AT_decl_file` according to D91014
Apply changes from https://reviews.llvm.org/D91014 to other places where DWARF entries are being processed.

Differential Revision: https://reviews.llvm.org/D96778
2021-03-01 16:01:11 +01:00
Adrian Prantl 057efa9916 Make the error condition in Value::ValueType explicit (NFC)
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
2021-02-12 16:12:31 -08:00
David Blaikie 78d41a1295 lldb: Add support for printing variables with DW_AT_ranges on DW_TAG_subprograms
Finishing out the support (to the best of my knowledge/based on current
testing running the whole check-lldb with a clang forcibly using
DW_AT_ranges on all DW_TAG_subprograms) for this feature.

Differential Revision: https://reviews.llvm.org/D94064
2021-01-24 18:39:06 -08:00
Jonas Devlieghere 5c1c8443eb [lldb] Abstract scoped timer logic behind LLDB_SCOPED_TIMER (NFC)
This patch introduces a LLDB_SCOPED_TIMER macro to hide the needlessly
repetitive creation of scoped timers in LLDB. It's similar to the
LLDB_LOG(F) macro.

Differential revision: https://reviews.llvm.org/D93663
2020-12-22 09:10:27 -08:00
António Afonso d7be9a4647 Revert "Check if debug line sequences are starting after the first code segment"
This reverts commit 265a38fbc5.
2020-11-09 11:45:35 -08:00
António Afonso a9dcd15f50 Revert "Ignores functions that have a range starting outside of a code section"
This reverts commit df30bc0168.
2020-11-09 09:07:48 -08:00
António Afonso df30bc0168 Ignores functions that have a range starting outside of a code section
This is a similar patch to https://reviews.llvm.org/D87172. Greg said we should also do it for functions.

Reviewed By: clayborg, labath

Differential Revision: https://reviews.llvm.org/D87173
2020-11-09 08:26:08 -08:00
António Afonso 265a38fbc5 Check if debug line sequences are starting after the first code segment
I found a few cases where entries in the debug_line for a specific line of code have invalid entries (the address is outside of a code section or no section at all) and also valid entries. When this happens lldb might not set the breakpoint because the first line entry it will find in the line table might be the invalid one and since it's range is "invalid" no location is resolved. To get around this I changed the way we parse the line sequences to ignore those starting at an address under the first code segment.
Greg suggested to implement it this way so we don't need to check all sections for every line sequence.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D87172
2020-11-09 08:26:00 -08:00
Jan Kratochvil a136699b2a [nfc] [lldb] Align `user_id_t` format to the current `DIERef` format
Current user_id_t format is:
        63{isDebugTypes} 62..32{dwo || 7fffffff}
        31..0 {die_offset}
while current DIERef format is (I have made up the bit positions but the
field widths do match):
        63{m_section==isDebugTypes} 62{m_dwo_num_valid} 61..32{m_dwo_num}
        31..0 {m_die_offset}

Proposing to change user_id_t to:
        63{isDebugTypes} 62{dwo_is_valid} 61..32{dwo; 0 if !valid}
        31..0 {die_offset}

There is no benefit of having 31-bits wide dwo_num in user_id_t when it
gets converted to 30-bits width in DIERef.

This patch is for future DWZ patchset which extends the dwo_is_valid bit
into a 2-bit field (normal, DWO, DWZ, DWZcommon) so that both user_id_t
and DIERef can be changed then the same way.

It would be best to somehow unify user_id_t and DIERef but I do not plan
to do that. user_id_t should probably remain a number for the Python API
compatibility while there still needs to be some class with all the
methods to access it.

SymbolFileDWARF::GetDwpSymbolFile() and SymbolFileDWARF::GetDIE use
0x3fffffff for DWP but that does not clash:

formerly:
  31bits32..62:0x7fffffff = normal unit / not any DWO
  31bits32..62:0x3fffffff = DWP
  31bits32..62:others = DWO unit number

after this patch:
  bit62=0 30bits32..61:any = normal unit / not any DWO
  bit62=1 30bits32..61:0x3fffffff = DWP
  bit62=1 30bits32..61:others = DWO unit number

Differential Revision: https://reviews.llvm.org/D90413
2020-10-30 16:50:52 +01:00
Pavel Labath 8485ee781f [lldb/DWARF] Fix dwo flavour of TestTypeGetModule
SymbolFileDWARF::GetTypes was not handling dwo correctly. The fix is
simple -- adding a GetNonSkeletonUnit call -- but I've snuck in a small
refactor as well.
2020-10-30 15:20:27 +01:00
Jan Kratochvil 41f2bb232c [nfc] [lldb] Remove excessive parentheses in SymbolFileDWARF::GetUID 2020-10-29 18:01:37 +01:00
Jan Kratochvil 0e5248be86 [nfc] [lldb] Move LookupAddress to DWARFCompileUnit
LookupAddress makes no sense for DWARFTypeUnit.
Also make GetNonSkeletonUnit to preserve the called type.

Differential Revision: https://reviews.llvm.org/D89646
2020-10-19 12:44:33 +02:00
Adrian Prantl 9b1c06c0e8 Move initialization of Variable::m_loc_is_const_data into constructor (NFC)
This makes it symmetric with all other flags and makes it easier to
not forget to initialize it.

https://reviews.llvm.org/D89351
2020-10-13 17:01:28 -07:00
Jan Kratochvil 54434dc4dc [nfc] [lldb] Simplify calling SymbolFileDWARF::GetDWARFCompileUnit
Only SymbolFileDWARF::ParseCompileUnit creates a CompileUnit and it uses
DWARFCompileUnit for that.

Differential Revision: https://reviews.llvm.org/D89165
2020-10-12 13:26:54 +02:00
Pavel Labath 1f9595ede4 [lldb] Reduce intentation in SymbolFileDWARF::ParseVariableDIE
using early exits. NFC.
2020-08-28 11:44:03 +02:00
Pavel Labath 9f5927e42b [lldb/DWARF] Fix handling of variables with both location and const_value attributes
Class-level static constexpr variables can have both DW_AT_const_value
(in the "declaration") and a DW_AT_location (in the "definition")
attributes. Our code was trying to handle this, but it was brittle and
hard to follow (and broken) because it was processing the attributes in
the order in which they were found.

Refactor the code to make the intent clearer -- DW_AT_location trumps
DW_AT_const_value, and fix the bug which meant that we were not
displaying these variables properly (the culprit was the delayed parsing
of the const_value attribute due to a need to fetch the variable type.

Differential Revision: https://reviews.llvm.org/D86615
2020-08-27 15:05:47 +02:00
Pavel Labath 82982304d7 [lldb/DWARF] More DW_AT_const_value fixes
This fixes several issues in handling of DW_AT_const_value attributes:
- the first is that the size of the data given by data forms does not
  need to match the size of the underlying variable. We already had the
  case to handle this for DW_FORM_(us)data -- this extends the handling
  to other data forms. The main reason this was not picked up is because
  clang uses leb forms in these cases while gcc prefers the fixed-size
  ones.
- The handling of DW_AT_strp form was completely broken -- we would end
  up using the pointer value as the result. I've reorganized this code
  so that it handles all string forms uniformly.
- In case of a completely bogus form we would crash due to
  strlen(nullptr).

Depends on D86311.

Differential Revision: https://reviews.llvm.org/D86348
2020-08-26 13:17:26 +02:00
Adrian Prantl 02f5837363 Thread ExecutionContextScope through GetByteSize where possible (NFC-ish)
This patch has no effect for C and C++. In more dynamic languages,
such as Objective-C and Swift GetByteSize() needs to call into the
language runtime, so it's important to pass one in where possible. My
primary motivation for this is some work I'm doing on the Swift
branch, however, it looks like we are also seeing warnings in
Objective-C that this may resolve.  Everything in the SymbolFile
hierarchy still passes in nullptrs, because we don't have an execution
context in SymbolFile, since SymbolFile transcends processes.

Differential Revision: https://reviews.llvm.org/D84267
2020-07-22 08:56:29 -07:00
Pavel Labath f3fab392f5 [lldb/DWARF] Don't get confused by line sequences with tombstone values
Summary:
With D81784, lld has started debug info resolving relocations to
garbage-collected symbols as -1 (instead of relocation addend). For an
unaware consumer this generated sequences which seemingly wrap the
address space -- their first entry was 0xfffff, but all other entries
were low numbers.

Lldb stores line sequences concatenated into one large vector, sorted by
the first entry, and searched with std::lower_bound. This resulted in
the low-value entries being placed at the end of the vector, which
utterly confused the lower_bound algorithm, and caused it to not find a
match. (Previously, these sequences would be at the start of the vector,
and normally would contain addresses that are far smaller than any real
address we want to look up, so std::lower_bound was fine.)

This patch makes lldb ignore these kinds of sequences completely. It
does that by changing the construction algorithm from iterating over the
rows (as parsed by llvm), to iterating over the sequences. This is
important because the llvm parsed performs validity checks when
constructing the sequence array, whereas the row array contains raw
data.

Reviewers: JDevlieghere, MaskRay

Differential Revision: https://reviews.llvm.org/D83957
2020-07-17 11:51:52 +02:00
Vedant Kumar 6cfc90b9b7 [Function] Lock the function when parsing call site info
Summary:
DWARF-parsing methods in SymbolFileDWARF which update module state
typically take the module lock. ParseCallEdgesInFunction doesn't do
this, but higher-level locking within lldb::Function (which owns the
storage for parsed call edges) is necessary.

The lack of locking could explain some as-of-yet unreproducible crashes
which occur in Function::GetTailCallingEdges(). In these crashes, the
`m_call_edges` vector is non-empty but contains a nullptr, which
shouldn't be possible. (If this vector is non-empty, it _must_ contain a
non-null unique_ptr.)

This may address rdar://55622443 and rdar://65119458.

Reviewers: jasonmolenda, friss, jingham

Subscribers: aprantl, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D83359
2020-07-09 10:37:09 -07:00
Jonas Devlieghere 06412dae82 [lldb] Use std::make_unique<> (NFC)
Update the rest of lldb to use std::make_unique<>. I used clang-tidy to
automate this, which probably missed cases that are wrapped in ifdefs.
2020-06-24 17:48:40 -07:00
Jonas Devlieghere 2b34632a57 [lldb/SymbolFile] Don't parse the whole line table for the support files
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
2020-06-12 09:39:17 -07:00
Jan Kratochvil 4515d35f5c [lldb] Fix DW_TAG_GNU_call_site-DW_AT_low_pc as produced by GCC
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
2020-06-09 13:41:41 +02:00
Pavel Labath 0081149f96 [lldb/DWARF] Fix PC value for artificial tail call frames for the "GNU" case
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
2020-06-08 14:44:36 +02:00
Pavel Labath bddd288826 [lldb/DWARF] Add support for pre-standard GNU call site attributes
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
2020-06-02 12:57:51 +02:00
Adrian Prantl 01fc85dc96 ParseXcodeSDK: Register both the CU module and the SymbolFile module.
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>
2020-05-06 16:46:22 -07:00
Adrian Prantl 5935227e11 Add an explicit API to read the Xcode SDK DWARF attribute from compile units
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
2020-05-06 13:16:16 -07:00
Pavel Labath 2cf69684fb [lldb/DWARF] Fix a split-dwarf crash while parsing compile units
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.
2020-04-29 16:21:11 +02:00
Jan Kratochvil d482fe2add [nfc] [lldb] DWARF callbacks: DIERef -> DWARFDIE
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
2020-04-22 17:11:50 +02:00
Davide Italiano ce7790044f [DWARF] Rename a function and comment it for clarity.
Pointed out by Adrian.
2020-04-16 15:37:09 -07:00
Jan Kratochvil 5e04b5f2fa [nfc] [lldb] Introduce DWARF callbacks (fixed-up)
As requested by @labath in https://reviews.llvm.org/D73206#1949516
providing DWARF index callbacks refactorization.

It is a re-landing of the patch with a regression fix the previous
commit had.

Differential Revision: https://reviews.llvm.org/D77327
2020-04-15 23:40:54 +02:00
Jan Kratochvil 9289f34390 Revert "[nfc] [lldb] Introduce DWARF callbacks"
This reverts commit bd47c470d1.

It broke Green Dragon, reason is unknown to me so far:
  http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/15323/consoleFull

Differential Revision: https://reviews.llvm.org/D77327
2020-04-15 15:12:59 +02:00
Jan Kratochvil bd47c470d1 [nfc] [lldb] Introduce DWARF callbacks
As requested by @labath in https://reviews.llvm.org/D73206#1949516
providing DWARF index callbacks refactorization.

Differential Revision: https://reviews.llvm.org/D77327
2020-04-15 10:37:38 +02:00
Jan Kratochvil 8fbac4e1a2 [nfc] [lldb] Unindent code
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
2020-04-09 20:43:00 +02:00
Davide Italiano d51b38f1b3 [DWARF] Not all the constant variables are "static".
Fixes rdar://problem/61402307

Differential Revision: https://reviews.llvm.org/D77698
2020-04-08 11:07:19 -07:00
Adrian Prantl 1e05d7b3d3 Remap the target (Xcode) SDK directory to the host SDK directory.
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
2020-04-06 15:51:30 -07:00