This patch add the ability to cache the manual DWARF indexing results to disk for faster subsequent debug sessions. Manual DWARF indexing is time consuming and causes all DWARF to be fully parsed and indexed each time you debug a binary that doesn't have an acceptable accelerator table. Acceptable accelerator tables include .debug_names in DWARF5 or Apple accelerator tables.
This patch breaks up testing by testing all of the encoding and decoding of required C++ objects in a gtest unit test, and then has a test to verify the debug info cache is generated correctly.
This patch also adds the ability to track when a symbol table or DWARF index is loaded or saved to the cache in the "statistics dump" command. This is essential to know in statistics as it can help explain why a debug session was slower or faster than expected.
Reviewed By: labath, wallace
Differential Revision: https://reviews.llvm.org/D115951
Skeleton vs. DWO units mismatch has been fixed in D106270. As they both
have type DWARFUnit it is a bit difficult to debug. So it is better to
make it safe against future changes.
Reviewed By: kimanh, clayborg
Differential Revision: https://reviews.llvm.org/D107659
LLDB has a few different styles of header guards and they're not very
consistent because things get moved around or copy/pasted. This patch
unifies the header guards across LLDB and converts everything to match
LLVM's style.
Differential revision: https://reviews.llvm.org/D74743
Summary:
When dwo support was introduced, it used a trick where debug info
entries were referenced by the offset of the compile unit in the main
file, but the die offset was relative to the dwo file. Although there
was some elegance to it, this representation was starting to reach its
breaking point:
- the fact that the skeleton compile unit owned the DWO file meant that
it was impossible (or at least hard and unintuitive) to support DWO
files containing more than one compile unit. These kinds of files are
produced by LTO for example.
- it made it impossible to reference any DIEs in the skeleton compile
unit (although the skeleton units are generally empty, clang still
puts some info into them with -fsplit-dwarf-inlining).
- (current motivation) it made it very hard to support type units placed
in DWO files, as type units don't have any skeleton units which could
be referenced in the main file
This patch addresses this problem by introducing an new
"dwo_num" field to the DIERef class, whose purpose is to identify the
dwo file. It's kind of similar to the dwo_id field in DWARF5 unit
headers, but while this is a 64bit hash whose main purpose is to catch
file mismatches, this is just a smaller integer used to indentify a
loaded dwo file. Currently, this is based on the index of the skeleton
compile unit which owns the dwo file, but it is intended to be
eventually independent of that (to support the LTO use case).
Simultaneously the cu_offset is dropped to conserve space, as it is no
longer necessary. This means we can remove the "BaseObjectOffset" field
from the DWARFUnit class. It also means we can remove some of the
workarounds put in place to support the skeleton-unit+dwo-die combo.
More work is needed to remove all of them, which is out of scope of this
patch.
Reviewers: JDevlieghere, clayborg, aprantl
Subscribers: mehdi_amini, dexonsmith, arphaman, lldb-commits
Differential Revision: https://reviews.llvm.org/D63428
llvm-svn: 364009
My apologies for the large patch. With the exception of ConstString.h
itself it was entirely produced by sed.
ConstString has exactly one const char * data member, so passing a
ConstString by reference is not any more efficient than copying it by
value. In both cases a single pointer is passed. But passing it by
value makes it harder to accidentally return the address of a local
object.
(This fixes rdar://problem/48640859 for the Apple folks)
Differential Revision: https://reviews.llvm.org/D59030
llvm-svn: 355553
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
UniqueCStringMap "sorts" the entries for fast lookup, but really it only cares about uniqueness. ConstString can be compared by pointer alone, rather than with strcmp, resulting in much faster comparisons. Change the interface to take ConstString instead, and propagate use of the type to the callers where appropriate.
Reviewers: #lldb, clayborg
Reviewed By: clayborg
Subscribers: labath, jasonmolenda, lldb-commits
Differential Revision: https://reviews.llvm.org/D32316
Patch by Scott Smith <scott.smith@purestorage.com>.
llvm-svn: 301908
*** to conform to clang-format’s LLVM style. This kind of mass change has
*** two obvious implications:
Firstly, merging this particular commit into a downstream fork may be a huge
effort. Alternatively, it may be worth merging all changes up to this commit,
performing the same reformatting operation locally, and then discarding the
merge for this particular commit. The commands used to accomplish this
reformatting were as follows (with current working directory as the root of
the repository):
find . \( -iname "*.c" -or -iname "*.cpp" -or -iname "*.h" -or -iname "*.mm" \) -exec clang-format -i {} +
find . -iname "*.py" -exec autopep8 --in-place --aggressive --aggressive {} + ;
The version of clang-format used was 3.9.0, and autopep8 was 1.2.4.
Secondly, “blame” style tools will generally point to this commit instead of
a meaningful prior commit. There are alternatives available that will attempt
to look through this change and find the appropriate prior commit. YMMV.
llvm-svn: 280751
Re-commit the change after fixing a lot of race condition in LLDB
exposed by this change
Loading the debug info from a large application is the slowest task
LLDB do. This CL makes most of the dwarf parsing code multi-threaded.
As a result the speed of "attach; backtrace; exit;" when the inferior
is an LLDB with full debug info increased by a factor of 2.
Differential revision: http://reviews.llvm.org/D13662
llvm-svn: 251106
Revert it bacuse it introduces several race condition detected by
the build bots.
This reverts commit 5107a5ebdb7c4571a30a7098b40bf8098b678447.
llvm-svn: 250832
Loading the debug info from a large application is the slowest task
LLDB do. This CL makes most of the dwarf parsing code multi-threaded.
As a result the speed of "attach; backtrace; exit;" when the inferior
is an LLDB with full debug info increased by a factor of 2 (on my machine).
Differential revision: http://reviews.llvm.org/D13662
llvm-svn: 250821
* Create new dwo symbol file class
* Add handling for .dwo sections
* Change indexes in SymbolFileDWARF to store compile unit offset next to
DIE offset
* Propagate queries from dwarf compile unit to the dwo compile unit
where applicable
Differential revision: http://reviews.llvm.org/D12291
llvm-svn: 247132
//------------------------------------------------------------------
/// Get all types matching \a type_mask from debug info in this
/// module.
///
/// @param[in] type_mask
/// A bitfield that consists of one or more bits logically OR'ed
/// together from the lldb::TypeClass enumeration. This allows
/// you to request only structure types, or only class, struct
/// and union types. Passing in lldb::eTypeClassAny will return
/// all types found in the debug information for this module.
///
/// @return
/// A list of types in this module that match \a type_mask
//------------------------------------------------------------------
lldb::SBTypeList
SBModule::GetTypes (uint32_t type_mask)
//------------------------------------------------------------------
/// Get all types matching \a type_mask from debug info in this
/// compile unit.
///
/// @param[in] type_mask
/// A bitfield that consists of one or more bits logically OR'ed
/// together from the lldb::TypeClass enumeration. This allows
/// you to request only structure types, or only class, struct
/// and union types. Passing in lldb::eTypeClassAny will return
/// all types found in the debug information for this compile
/// unit.
///
/// @return
/// A list of types in this compile unit that match \a type_mask
//------------------------------------------------------------------
lldb::SBTypeList
SBCompileUnit::GetTypes (uint32_t type_mask = lldb::eTypeClassAny);
This lets you request types by filling out a mask that contains one or more bits from the lldb::TypeClass enumerations, so you can only get the types you really want.
llvm-svn: 184251
Address ranges are now split up into two different tables:
- one in DWARFDebugInfo that is compile unit specific
- one in each DWARFCompileUnit that has exact function DIE offsets
This helps keep the size of the aranges down since the main table will get
uniqued and sorted and have consecutive ranges merged. We then only parse the
compile unit one on demand once we have determined that a compile unit contains
the address in question. We also now use the .debug_aranges section if there
is one instead of always indexing the DWARF manually.
NameToDIE now uses a UniqueCStringMap<dw_offset> map instead of a std::map.
std::map is very bulky as each node has 3 pointers and the key and value types.
This gets our NameToDIE entry down to 12 bytes each instead of 48 which saves
us a lot of memory when we have very large DWARF.
DWARFDebugAranges now has a smaller footprint for each range it contains to
save on memory.
llvm-svn: 139557
DWARF accelerator table sections to the DWARF parser. These sections are similar
to the .debug_pubnames and .debug_pubtypes, but they are designed to be hash tables
that are saved to disc in a way that the sections can just be loaded into memory
and used without any work on the debugger side. The .debug_pubnames and .debug_pubtypes
sections are not ordered, contain a copy of the name in the section itself which
makes these sections quite large, they only include publicly exported names (so no
static functions, no types defined inside functions), many compilers put different
information in them making them very unreliable so most debugger ignore these sections
and parse the DWARF on their own. The tables must also be parsed and sorted in order
to be used effectively. The new sections can be quickly loaded and very efficiently be used
to do name to DIE lookups with very little up front work. The format of these new
sections will be changing while we work out the bugs, but we hope to have really
fast name to DIE lookups soon.
llvm-svn: 138979
all types in all compile units. I added a new kind of accelerator table to
the DWARF that allows us to index the DWARF compile units and DIEs in a way
that doesn't require the data to stay loaded. Currently when indexing the
DWARF we check if the compile unit had parsed its DIEs and if it hasn't we
index the data and free all of the DIEs so we can reparse later when we need
to after using one of our complete accelerator tables to determine we need
to reparse some DWARF. If the DIEs had already been parsed we leave them
loaded. The new accelerator table uses the "const char *" pointers from our
ConstString class as the keys, and NameToDIE::Info as the value. This info
contains the compile unit index and the DIE index which means we are pointed
right to the DIE we need unlike the other DWARF accelerator tables that often
just point us to the compile unit we would find our answer in.
llvm-svn: 113933
Greg Clayton