UniqueCStringMap<T> objects are a std::vector<UniqueCStringMap::Entry> objects where the Entry object contains a ConstString + T. The values in the vector are sorted first by ConstString and then by the T value. ConstString objects are simply uniqued "const char *" values and when we compare we use the actual string pointer as the value we sort by. This caused a problem when we saved the symbol table name indexes and debug info indexes to disk in one process when they were sorted, and then loaded them into another process when decoding them from the cache files. Why? Because the order in which the ConstString objects were created are now completely different and the string pointers will no longer be sorted in the new process the cache was loaded into.
The unit tests created for the initial patch didn't catch the encoding and decoding issues of UniqueCStringMap<T> because they were happening in the same process and encoding and decoding would end up createing sorted UniqueCStringMap<T> objects due to the constant string pool being exactly the same.
This patch does the sort and also reserves the right amount of entries in the UniqueCStringMap::m_map prior to adding them all to avoid doing multiple allocations.
Added a unit test that loads an object file from yaml, and then I created a cache file for the original file and removed the cache file's signature mod time check since we will generate an object file from the YAML, and use that as the object file for the Symtab object. Then we load the cache data from the array of symtab cache bytes so that the ConstString "const char *" values will not match the current process, and verify we can lookup the 4 names from the object file in the symbol table.
Differential Revision: https://reviews.llvm.org/D124572
This diff introduces a new symbol on-demand which skips
loading a module's debug info unless explicitly asked on
demand. This provides significant performance improvement
for application with dynamic linking mode which has large
number of modules.
The feature can be turned on with:
"settings set symbols.load-on-demand true"
The feature works by creating a new SymbolFileOnDemand class for
each module which wraps the actual SymbolFIle subclass as member
variable. By default, most virtual methods on SymbolFileOnDemand are
skipped so that it looks like there is no debug info for that module.
But once the module's debug info is explicitly requested to
be enabled (in the conditions mentioned below) SymbolFileOnDemand
will allow all methods to pass through and forward to the actual SymbolFile
which would hydrate module's debug info on-demand.
In an internal benchmark, we are seeing more than 95% improvement
for a 3000 modules application.
Currently we are providing several ways to on demand hydrate
a module's debug info:
* Source line breakpoint: matching in supported files
* Stack trace: resolving symbol context for an address
* Symbolic breakpoint: symbol table match guided promotion
* Global variable: symbol table match guided promotion
In all above situations the module's debug info will be on-demand
parsed and indexed.
Some follow-ups for this feature:
* Add a command that allows users to load debug info explicitly while using a
new or existing command when this feature is enabled
* Add settings for "never load any of these executables in Symbols On Demand"
that takes a list of globs
* Add settings for "always load the the debug info for executables in Symbols
On Demand" that takes a list of globs
* Add a new column in "image list" that shows up by default when Symbols On
Demand is enable to show the status for each shlib like "not enabled for
this", "debug info off" and "debug info on" (with a single character to
short string, not the ones I just typed)
Differential Revision: https://reviews.llvm.org/D121631
Currently, lldb crashes when adding a stop hook with --shlib because we
unconditionally use the target in SymbolContextSpecifier::AddSpecification.
This patch prevents the crash and add a test.
rdar://68524781
Differential revision: https://reviews.llvm.org/D123746
Currently, all data buffers are assumed to be writable. This is a
problem on macOS where it's not allowed to load unsigned binaries in
memory as writable. To be more precise, MAP_RESILIENT_CODESIGN and
MAP_RESILIENT_MEDIA need to be set for mapped (unsigned) binaries on our
platform.
Binaries are mapped through FileSystem::CreateDataBuffer which returns a
DataBufferLLVM. The latter is backed by a llvm::WritableMemoryBuffer
because every DataBuffer in LLDB is considered to be writable. In order
to use a read-only llvm::MemoryBuffer I had to split our abstraction
around it.
This patch distinguishes between a DataBuffer (read-only) and
WritableDataBuffer (read-write) and updates LLDB to use the appropriate
one.
rdar://74890607
Differential revision: https://reviews.llvm.org/D122856
Applied modernize-use-default-member-init clang-tidy check over LLDB.
It appears in many files we had already switched to in class member init but
never updated the constructors to reflect that. This check is already present in
the lldb/.clang-tidy config.
Differential Revision: https://reviews.llvm.org/D121481
This patch adds support for showing progress events when using lldb on
the command line. It spawns a separate thread that listens for progress
events and prints them to the debugger's output stream.
It's nothing fancy (yet), for now it just prints the progress message.
If we know the total number of items being processed, we prefix the
message with something like [1/100], similar to ninja's output.
This patch doesn't use any fancy terminal manipulation: it uses a simple
carriage return (\r) to bring the cursor to the front of the line and
vt100 escape codes to clear the (rest) of the line.
Differential revision: https://reviews.llvm.org/D120972
We have using namespace llvm::dwarf in dwarf.h header globally. Replacing that
with a using namespace within lldb_private::dwarf and moving to a
using namespace lldb_private::dwarf in .cpp files and fully qualified names
in the few header files.
Differential Revision: https://reviews.llvm.org/D120836
This allows `image lookup -a ... -v` to print variables only if the given
address is covered by the valid ranges of the variables. Since variables created
in dwarf plugin always has empty scope range, print the variable if it has
empty scope.
Differential Revision: https://reviews.llvm.org/D119963
As usual with that header cleanup series, some implicit dependencies now need to
be explicit:
llvm/DebugInfo/DWARF/DWARFContext.h no longer includes:
- "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
- "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
- "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
- "llvm/DebugInfo/DWARF/DWARFDebugAranges.h"
- "llvm/DebugInfo/DWARF/DWARFDebugFrame.h"
- "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
- "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
- "llvm/DebugInfo/DWARF/DWARFGdbIndex.h"
- "llvm/DebugInfo/DWARF/DWARFSection.h"
- "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
- "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
Plus llvm/Support/Errc.h not included by a bunch of llvm/DebugInfo/DWARF/DWARF*.h files
Preprocessed lines to build llvm on my setup:
after: 1065629059
before: 1066621848
Which is a great diff!
Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D119723
The symbol table needs to demangle all symbol names when building its
index. However, this doesn't require the full mangled name: we only need
the base name and the function declaration context. Currently, we always
construct the demangled string during indexing and cache it in the
string pool as a way to speed up future lookups.
Constructing the demangled string is by far the most expensive step of
the demangling process, because the output string can be exponentially
larger than the input and unless you're dumping the symbol table, many
of those demangled names will not be needed again.
This patch avoids constructing the full demangled string when we can
partially demangle. This speeds up indexing and reduces memory usage.
I gathered some numbers by attaching to Slack:
Before
------
Memory usage: 280MB
Benchmark 1: ./bin/lldb -n Slack -o quit
Time (mean ± σ): 4.829 s ± 0.518 s [User: 4.012 s, System: 0.208 s]
Range (min … max): 4.624 s … 6.294 s 10 runs
After
-----
Memory usage: 189MB
Benchmark 1: ./bin/lldb -n Slack -o quit
Time (mean ± σ): 4.182 s ± 0.025 s [User: 3.536 s, System: 0.192 s]
Range (min … max): 4.152 s … 4.233 s 10 runs
Differential revision: https://reviews.llvm.org/D118814
Have the different ::Parse.* methods return the demangled string
directly instead of having to go through ::GetBufferRef.
Differential revision: https://reviews.llvm.org/D118953
Most of our code was including Log.h even though that is not where the
"lldb" log channel is defined (Log.h defines the generic logging
infrastructure). This worked because Log.h included Logging.h, even
though it should.
After the recent refactor, it became impossible the two files include
each other in this direction (the opposite inclusion is needed), so this
patch removes the workaround that was put in place and cleans up all
files to include the right thing. It also renames the file to LLDBLog to
better reflect its purpose.
This is a re-submission of 24d2405588
without the hunks in HostNativeThreadBase.{h,cpp}, which break builds
on Windows.
Identified with modernize-use-nullptr.
This reverts commit 913457acf0.
It again broke builds on Windows:
lldb/source/Host/common/HostNativeThreadBase.cpp(37,14): error:
assigning to 'lldb::thread_result_t' (aka 'unsigned int') from
incompatible type 'std::nullptr_t'
This is a re-submission of 24d2405588
without the hunk in HostNativeThreadBase.h, which breaks builds on
Windows.
Identified with modernize-use-nullptr.
This reverts commit 24d2405588.
Breaks building on Windows:
../../lldb/include\lldb/Host/HostNativeThreadBase.h(49,36): error:
cannot initialize a member subobject of type 'lldb::thread_result_t'
(aka 'unsigned int') with an rvalue of type 'std::nullptr_t'
lldb::thread_result_t m_result = nullptr;
^~~~~~~
1 error generated.
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
This is an updated version of the https://reviews.llvm.org/D113789 patch with the following changes:
- We no longer modify modification times of the cache files
- Use LLVM caching and cache pruning instead of making a new cache mechanism (See DataFileCache.h/.cpp)
- Add signature to start of each file since we are not using modification times so we can tell when caches are stale and remove and re-create the cache file as files are changed
- Add settings to control the cache size, disk percentage and expiration in days to keep cache size under control
This patch enables symbol tables to be cached in the LLDB index cache directory. All cache files are in a single directory and the files use unique names to ensure that files from the same path will re-use the same file as files get modified. This means as files change, their cache files will be deleted and updated. The modification time of each of the cache files is not modified so that access based pruning of the cache can be implemented.
The symbol table cache files start with a signature that uniquely identifies a file on disk and contains one or more of the following items:
- object file UUID if available
- object file mod time if available
- object name for BSD archive .o files that are in .a files if available
If none of these signature items are available, then the file will not be cached. This keeps temporary object files from expressions from being cached.
When the cache files are loaded on subsequent debug sessions, the signature is compare and if the file has been modified (uuid changes, mod time changes, or object file mod time changes) then the cache file is deleted and re-created.
Module caching must be enabled by the user before this can be used:
symbols.enable-lldb-index-cache (boolean) = false
(lldb) settings set symbols.enable-lldb-index-cache true
There is also a setting that allows the user to specify a module cache directory that defaults to a directory that defaults to being next to the symbols.clang-modules-cache-path directory in a temp directory:
(lldb) settings show symbols.lldb-index-cache-path
/var/folders/9p/472sr0c55l9b20x2zg36b91h0000gn/C/lldb/IndexCache
If this setting is enabled, the finalized symbol tables will be serialized and saved to disc so they can be quickly loaded next time you debug.
Each module can cache one or more files in the index cache directory. The cache file names must be unique to a file on disk and its architecture and object name for .o files in BSD archives. This allows universal mach-o files to support caching multuple architectures in the same module cache directory. Making the file based on the this info allows this cache file to be deleted and replaced when the file gets updated on disk. This keeps the cache from growing over time during the compile/edit/debug cycle and prevents out of space issues.
If the cache is enabled, the symbol table will be loaded from the cache the next time you debug if the module has not changed.
The cache also has settings to control the size of the cache on disk. Each time LLDB starts up with the index cache enable, the cache will be pruned to ensure it stays within the user defined settings:
(lldb) settings set symbols.lldb-index-cache-expiration-days <days>
A value of zero will disable cache files from expiring when the cache is pruned. The default value is 7 currently.
(lldb) settings set symbols.lldb-index-cache-max-byte-size <size>
A value of zero will disable pruning based on a total byte size. The default value is zero currently.
(lldb) settings set symbols.lldb-index-cache-max-percent <percentage-of-disk-space>
A value of 100 will allow the disc to be filled to the max, a value of zero will disable percentage pruning. The default value is zero.
Reviewed By: labath, wallace
Differential Revision: https://reviews.llvm.org/D115324
While profiling lldb (from swift/llvm-project), these timers were noticed to be short lived and high firing, and so they add noise more than value.
The data points I recorded are:
`FindTypes_Impl`: 49,646 calls, 812ns avg, 40.33ms total
`AppendSymbolIndexesWithName`: 36,229 calls, 913ns avg, 33.09ms total
`FindAllSymbolsWithNameAndType`: 36,229 calls, 1.93µs avg, 70.05ms total
`FindSymbolsWithNameAndType`: 23,263 calls, 3.09µs avg, 71.88ms total
Differential Revision: https://reviews.llvm.org/D115182
Symbol table parsing has evolved over the years and many plug-ins contained duplicate code in the ObjectFile::GetSymtab() that used to be pure virtual. With this change, the "Symbtab *ObjectFile::GetSymtab()" is no longer virtual and will end up calling a new "void ObjectFile::ParseSymtab(Symtab &symtab)" pure virtual function to actually do the parsing. This helps centralize the code for parsing the symbol table and allows the ObjectFile base class to do all of the common work, like taking the necessary locks and creating the symbol table object itself. Plug-ins now just need to parse when they are asked to parse as the ParseSymtab function will only get called once.
This is a retry of the original patch https://reviews.llvm.org/D113965 which was reverted. There was a deadlock in the Manual DWARF indexing code during symbol preloading where the module was asked on the main thread to preload its symbols, and this would in turn cause the DWARF manual indexing to use a thread pool to index all of the compile units, and if there were relocations on the debug information sections, these threads could ask the ObjectFile to load section contents, which could cause a call to ObjectFileELF::RelocateSection() which would ask for the symbol table from the module and it would deadlock. We can't lock the module in ObjectFile::GetSymtab(), so the solution I am using is to use a llvm::once_flag to create the symbol table object once and then lock the Symtab object. Since all APIs on the symbol table use this lock, this will prevent anyone from using the symbol table before it is parsed and finalized and will avoid the deadlock I mentioned. ObjectFileELF::GetSymtab() was never locking the module lock before and would put off creating the symbol table until somewhere inside ObjectFileELF::GetSymtab(). Now we create it one time inside of the ObjectFile::GetSymtab() and immediately lock it which should be safe enough. This avoids the deadlocks and still provides safety.
Differential Revision: https://reviews.llvm.org/D114288
This reverts commit 951b107eed.
Buildbots were failing, there is a deadlock in /Users/gclayton/Documents/src/llvm/clean/llvm-project/lldb/test/Shell/SymbolFile/DWARF/DW_AT_range-DW_FORM_sec_offset.s when ELF files try to relocate things.
Symbol table parsing has evolved over the years and many plug-ins contained duplicate code in the ObjectFile::GetSymtab() that used to be pure virtual. With this change, the "Symbtab *ObjectFile::GetSymtab()" is no longer virtual and will end up calling a new "void ObjectFile::ParseSymtab(Symtab &symtab)" pure virtual function to actually do the parsing. This helps centralize the code for parsing the symbol table and allows the ObjectFile base class to do all of the common work, like taking the necessary locks and creating the symbol table object itself. Plug-ins now just need to parse when they are asked to parse as the ParseSymtab function will only get called once.
Differential Revision: https://reviews.llvm.org/D113965
This is part of https://github.com/dlang/projects/issues/81 .
This patch enables support for D programming language demangler by using a
pretty printed stacktrace with demangled D symbols, when present.
Signed-off-by: Luís Ferreira <contact@lsferreira.net>
Reviewed By: JDevlieghere, teemperor
Differential Revision: https://reviews.llvm.org/D110578
Teach LLDB to understand INLINE and INLINE_ORIGIN records in breakpad.
They have the following formats:
```
INLINE inline_nest_level call_site_line call_site_file_num origin_num [address size]+
INLINE_ORIGIN origin_num name
```
`INLNIE_ORIGIN` is simply a string pool for INLINE so that we won't have
duplicated names for inlined functions and can show up anywhere in the symbol
file.
`INLINE` follows immediately after `FUNC` represents the ranges of momery
address that has functions inlined inside the function.
Differential Revision: https://reviews.llvm.org/D113330
The Swift stdlib uses absolute symbols in the dylib to communicate
feature flags to the process. LLDB's expression evaluator needs to be
able to find them. This wires up absolute symbols so they show up in
the symtab lookup command, which is also all that's needed for them to
be visible to the expression evaluator JIT.
rdar://85093828
Differential Revision: https://reviews.llvm.org/D113445
The new key/value pairs that are added to each module's stats are:
"debugInfoByteSize": The size in bytes of debug info for each module.
"debugInfoIndexTime": The time in seconds that it took to index the debug info.
"debugInfoParseTime": The time in seconds that debug info had to be parsed.
At the top level we add up all of the debug info size, parse time and index time with the following keys:
"totalDebugInfoByteSize": The size in bytes of all debug info in all modules.
"totalDebugInfoIndexTime": The time in seconds that it took to index all debug info if it was indexed for all modules.
"totalDebugInfoParseTime": The time in seconds that debug info was parsed for all modules.
Differential Revision: https://reviews.llvm.org/D112501
The new module stats adds the ability to measure the time it takes to parse and index the symbol tables for each module, and reports modules statistics in the output of "statistics dump" along with the path, UUID and triple of the module. The time it takes to parse and index the symbol tables are also aggregated into new top level key/value pairs at the target level.
Differential Revision: https://reviews.llvm.org/D112279
There is no reason why this function should be returning a ConstString.
While modifying these files, I also fixed several instances where
GetPluginName and GetPluginNameStatic were returning different strings.
I am not changing the return type of GetPluginNameStatic in this patch, as that
would necessitate additional changes, and this patch is big enough as it is.
Differential Revision: https://reviews.llvm.org/D111877
Replace misc. StringConvert uses with llvm::to_integer()
and llvm::to_float(), except for cases where further refactoring is
planned. The purpose of this change is to eliminate the StringConvert
API that is duplicate to LLVM, and less correct in behavior at the same
time.
Differential Revision: https://reviews.llvm.org/D110447
In all these years, we haven't found a use for this function (it has
zero callers). Lets just remove the boilerplate.
Differential Revision: https://reviews.llvm.org/D109600
This is enough to get the lit-based tests to pass on macOS.
Doesn't yet add build targets for:
- Any LLDB unit tests
- swig bindings
- various targets not needed by lit tests
LLDB has many dependency cycles, something GN doesn't allow. For
that reason, I've omitted some dependency edges. Hopefully we can
clean up the cycles one day.
LLDB has a public/private header distinction, but mostly ignores it.
Many libraries include private headers from other modules.
Since LLDB is the first target the LLVM/GN build that uses Objective-C++
code, add some machinery to the toolchain file to handle that.
Differential Revision: https://reviews.llvm.org/D109185
Greg Clayton