[lldb] Change CreateMemoryInstance to take a WritableDataBuffer

Change the CreateMemoryInstance interface to take a WritableDataBuffer.

Differential revision: https://reviews.llvm.org/D123073

[lldb] Refactor DataBuffer so we can map files as read-only

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
mem

[lldb] Refactor DataBuffer so we can map files as read-only

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

show more ...

[lldb] Rename Logging.h to LLDBLog.h and clean up includes

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
inf

[lldb] Rename Logging.h to LLDBLog.h and clean up includes

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.

show more ...

[lldb] Convert "LLDB" log channel to the new API

Added the ability to cache the finalized symbol tables subsequent debug sessions to start faster.

This is an updated version of the https://reviews.llvm.org/D113789 patch with the following changes:

Added the ability to cache the finalized symbol tables subsequent debug sessions to start faster.

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

show more ...

[NFC] Refactor symbol table parsing.

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

[NFC] Refactor symbol table parsing.

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

show more ...

Revert "[NFC] Refactor symbol table parsing."

This reverts commit 951b107eedab1829f18049443f03339dbb0db165.

Buildbots were failing, there is a deadlock in /Users/gclayton/Documents/src/llvm/clean/l

Revert "[NFC] Refactor symbol table parsing."

This reverts commit 951b107eedab1829f18049443f03339dbb0db165.

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.

show more ...

[NFC] Refactor symbol table parsing.

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

[NFC] Refactor symbol table parsing.

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

show more ...

Create synthetic symbol names on demand to improve memory consumption and startup times.

This is a resubmission of https://reviews.llvm.org/D105160 after fixing testing issues.

This fix was created

Create synthetic symbol names on demand to improve memory consumption and startup times.

This is a resubmission of https://reviews.llvm.org/D105160 after fixing testing issues.

This fix was created after profiling the target creation of a large C/C++/ObjC application that contained almost 4,000,000 redacted symbol names. The symbol table parsing code was creating names for each of these synthetic symbols and adding them to the name indexes. The code was also adding the object file basename to the end of the symbol name which doesn't allow symbols from different shared libraries to share the names in the constant string pool.

Prior to this fix this was creating 180MB of "___lldb_unnamed_symbol" symbol names and was taking a long time to generate each name, add them to the string pool and then add each of these names to the name index.

This patch fixes the issue by:

not adding a name to synthetic symbols at creation time, and allows name to be dynamically generated when accessed
doesn't add synthetic symbol names to the name indexes, but catches this special case as name lookup time. Users won't typically set breakpoints or lookup these synthetic names, but support was added to do the lookup in case it does happen
removes the object file baseanme from the generated names to allow the names to be shared in the constant string pool
Prior to this fix the startup times for a large application was:
12.5 seconds (cold file caches)
8.5 seconds (warm file caches)

After this fix:
9.7 seconds (cold file caches)
5.7 seconds (warm file caches)

The names of the symbols are auto generated by appending the symbol's UserID to the end of the "___lldb_unnamed_symbol" string and is only done when the name is requested from a synthetic symbol if it has no name.

Differential Revision: https://reviews.llvm.org/D106837

show more ...

Revert "Create synthetic symbol names on demand to improve memory consumption and startup times."

This reverts commit c8164d0276b97679e80db01adc860271ab4a5d11 and
43f6dad2344247976d5777f56a1fc29e39c

Revert "Create synthetic symbol names on demand to improve memory consumption and startup times."

This reverts commit c8164d0276b97679e80db01adc860271ab4a5d11 and
43f6dad2344247976d5777f56a1fc29e39c6c717 because it breaks
TestDyldTrieSymbols.py on GreenDragon.

show more ...

Create synthetic symbol names on demand to improve memory consumption and startup times.

This fix was created after profiling the target creation of a large C/C++/ObjC application that contained alm

Create synthetic symbol names on demand to improve memory consumption and startup times.

This fix was created after profiling the target creation of a large C/C++/ObjC application that contained almost 4,000,000 redacted symbol names. The symbol table parsing code was creating names for each of these synthetic symbols and adding them to the name indexes. The code was also adding the object file basename to the end of the symbol name which doesn't allow symbols from different shared libraries to share the names in the constant string pool.

Prior to this fix this was creating 180MB of "___lldb_unnamed_symbol" symbol names and was taking a long time to generate each name, add them to the string pool and then add each of these names to the name index.

This patch fixes the issue by:
- not adding a name to synthetic symbols at creation time, and allows name to be dynamically generated when accessed
- doesn't add synthetic symbol names to the name indexes, but catches this special case as name lookup time. Users won't typically set breakpoints or lookup these synthetic names, but support was added to do the lookup in case it does happen
- removes the object file baseanme from the generated names to allow the names to be shared in the constant string pool

Prior to this fix the startup times for a large application was:
12.5 seconds (cold file caches)
8.5 seconds (warm file caches)

After this fix:
9.7 seconds (cold file caches)
5.7 seconds (warm file caches)

The names of the symbols are auto generated by appending the symbol's UserID to the end of the "___lldb_unnamed_symbol" string and is only done when the name is requested from a synthetic symbol if it has no name.

Differential Revision: https://reviews.llvm.org/D105160

show more ...

Revert D104488 and friends since it broke the windows bot

Reverts commits:
"Fix failing tests after https://reviews.llvm.org/D104488."
"Fix buildbot failure after https://reviews.llvm.org/D104488."

Revert D104488 and friends since it broke the windows bot

Reverts commits:
"Fix failing tests after https://reviews.llvm.org/D104488."
"Fix buildbot failure after https://reviews.llvm.org/D104488."
"Create synthetic symbol names on demand to improve memory consumption and startup times."

This series of commits broke the windows lldb bot and then failed to fix all of the failing tests.

show more ...

Create synthetic symbol names on demand to improve memory consumption and startup times.

This fix was created after profiling the target creation of a large C/C++/ObjC application that contained alm

Create synthetic symbol names on demand to improve memory consumption and startup times.

This fix was created after profiling the target creation of a large C/C++/ObjC application that contained almost 4,000,000 redacted symbol names. The symbol table parsing code was creating names for each of these synthetic symbols and adding them to the name indexes. The code was also adding the object file basename to the end of the symbol name which doesn't allow symbols from different shared libraries to share the names in the constant string pool.

Prior to this fix this was creating 180MB of "___lldb_unnamed_symbol" symbol names and was taking a long time to generate each name, add them to the string pool and then add each of these names to the name index.

This patch fixes the issue by:
- not adding a name to synthetic symbols at creation time, and allows name to be dynamically generated when accessed
- doesn't add synthetic symbol names to the name indexes, but catches this special case as name lookup time. Users won't typically set breakpoints or lookup these synthetic names, but support was added to do the lookup in case it does happen
- removes the object file baseanme from the generated names to allow the names to be shared in the constant string pool

Prior to this fix the startup times for a large application was:
12.5 seconds (cold file caches)
8.5 seconds (warm file caches)

After this fix:
9.7 seconds (cold file caches)
5.7 seconds (warm file caches)

The names of the symbols are auto generated by appending the symbol's UserID to the end of the "___lldb_unnamed_symbol" string and is only done when the name is requested from a synthetic symbol if it has no name.

Differential Revision: https://reviews.llvm.org/D104488

show more ...

Improve performance when parsing symbol tables in mach-o files.

Some larger projects were loading quite slowly with the current LLDB on macOS and macOS simulator builds. I did some instrument traces

Improve performance when parsing symbol tables in mach-o files.

Some larger projects were loading quite slowly with the current LLDB on macOS and macOS simulator builds. I did some instrument traces and found 3 main culprits:
- a LLDB timer that was put into a function that was called too often
- a std::set that was keeping track of the address of symbols that were already added
- a unnamed function generator in ObjectFile that was going slow due to allocations

In order to see this in action I ran the latest LLDB on a large application with many frameworks using the following method:

(lldb) script import time; start_time = time.perf_counter()
(lldb) file Large.app
(lldb) script print(time.perf_counter() - start_time)

I first range "sudo purge" to clear the system file caches to simulate a cold startup of the debugger, followed by two iterations with warm file caches.

Prior to this fix I was seeing the following timings:

17.68 (cold)
14.56 (warm 1)
14.52 (warm 2)

After this fix I was seeing:

11.32 (cold)
8.43 (warm 1)
8.49 (warm 2)

Differential Revision: https://reviews.llvm.org/D103504

show more ...

[lldb] Simplify ObjectFile::FindPlugin (NFC)

Use early return to reduce the levels of indentation. Extract logic to
find object in container into helper function.

[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

[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

show more ...

[lldb][ObjectFile] Relocate sections for in-memory objects (e.g. received via JITLoaderGDB)

Part 2 of a fix for JITed code debugging. This has been a regression from 5.0 to 6.0 and it's still reprod

[lldb][ObjectFile] Relocate sections for in-memory objects (e.g. received via JITLoaderGDB)

Part 2 of a fix for JITed code debugging. This has been a regression from 5.0 to 6.0 and it's still reproducible on current master: https://bugs.llvm.org/show_bug.cgi?id=36209 Part 1 was D61611 a while ago.

The in-memory object files we obtain from JITLoaderGDB are not yet relocated. It looks like this used to happen on the LLDB side and my guess is that it broke with D38142. (However, it's hard to tell because the whole thing was broken already due to the bug in part 1.) The patch moved relocation resolution to a later point in time and didn't apply it to in-memory objects. I am not aware of any reason why we wouldn't resolve relocations per-se, so I made it unconditional here. On Debian, it fixes the bug for me and all tests in `check-lldb` are still fine.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D90769

show more ...

[lldb/Module] Allow for the creation of memory-only modules

Summary:
This patch extends the ModuleSpec class to include a
DataBufferSP which contains the module data. If this
data is provided, LLDB

[lldb/Module] Allow for the creation of memory-only modules

Summary:
This patch extends the ModuleSpec class to include a
DataBufferSP which contains the module data. If this
data is provided, LLDB won't try to hit the filesystem
to create the Module, but use only the data stored in
the ModuleSpec.

Reviewers: labath, espindola

Subscribers: emaste, MaskRay, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D83512

show more ...

[lldb] Add boilerplate to recognize the .debug_tu_index section

It's just like debug_cu_index, only for type units.

[lldb][NFC] Fix all formatting errors in .cpp file headers

Summary:
A *.cpp file header in LLDB (and in LLDB) should like this:
```
//===-- TestUtilities.cpp ----------------------------------------

[lldb][NFC] Fix all formatting errors in .cpp file headers

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

show more ...

[lldb/DWARF] Move location list sections into DWARFContext

These are the last sections not managed by the DWARFContext object. I
also introduce separate SectionType enums for dwo section variants, a

[lldb/DWARF] Move location list sections into DWARFContext

These are the last sections not managed by the DWARFContext object. I
also introduce separate SectionType enums for dwo section variants, as
this is necessary for proper handling of single-file split dwarf.

show more ...

[LLDB] [PECOFF] Make sure to set the address byte size in m_data after parsing headers

If not set, the address byte size was implied to be the one of the
host process.

This allows reverting the fun

[LLDB] [PECOFF] Make sure to set the address byte size in m_data after parsing headers

If not set, the address byte size was implied to be the one of the
host process.

This allows reverting the functional change from 31087b2ae9154, since
now PECOFF does the same as ELF and MachO wrt setting both byte order
and address size on m_data within ParseHeader.

Differential Revision: https://reviews.llvm.org/D71108

show more ...

[LLDB] Set the right address size on output DataExtractors from ObjectFile

If filling in a DataExtractor from an ObjectFile, e.g. via the
ReadSectionData method, the output DataExtractor gets the ad

[LLDB] Set the right address size on output DataExtractors from ObjectFile

If filling in a DataExtractor from an ObjectFile, e.g. via the
ReadSectionData method, the output DataExtractor gets the address
size from the m_data member.

ObjectFile's m_data member is initialized without knowledge about
the address size (so the address size is set based on the host's
sizeof(void*), and at that point within ObjectFile's constructor,
virtual methods implemented in subclasses (like GetAddressByteSize())
can't be called, therefore fix it up when filling in external
DataExtractors.

This makes sure that line tables from executables with a different
address size are parsed properly; previously this tripped up
DWARFDebugLine::LineTable::parse for 32 bit executables on a 64 bit
host, as the address size in the line table (4) didn't match the
one set in the DWARFDataExtractor.

Differential Revision: https://reviews.llvm.org/D70848

show more ...

[lldb] Add boilerplate to recognize the .debug_rnglists.dwo section

[Windows] Use information from the PE32 exceptions directory to construct unwind plans

This patch adds an implementation of unwinding using PE EH info. It allows to
get almost ideal call stacks on 6

[Windows] Use information from the PE32 exceptions directory to construct unwind plans

This patch adds an implementation of unwinding using PE EH info. It allows to
get almost ideal call stacks on 64-bit Windows systems (except some epilogue
cases, but I believe that they can be fixed with unwind plan disassembly
augmentation in the future).

To achieve the goal the CallFrameInfo abstraction was made. It is based on the
DWARFCallFrameInfo class interface with a few changes to make it less
DWARF-specific.

To implement the new interface for PECOFF object files the class PECallFrameInfo
was written. It uses the next helper classes:

- UnwindCodesIterator helps to iterate through UnwindCode structures (and
processes chained infos transparently);
- EHProgramBuilder with the use of UnwindCodesIterator constructs EHProgram;
- EHProgram is, by fact, a vector of EHInstructions. It creates an abstraction
over the low-level unwind codes and simplifies work with them. It contains
only the information that is relevant to unwinding in the unified form. Also
the required unwind codes are read from the object file only once with it;
- EHProgramRange allows to take a range of EHProgram and to build an unwind row
for it.

So, PECallFrameInfo builds the EHProgram with EHProgramBuilder, takes the ranges
corresponding to every offset in prologue and builds the rows of the resulted
unwind plan. The resulted plan covers the whole range of the function except the
epilogue.

Reviewers: jasonmolenda, asmith, amccarth, clayborg, JDevlieghere, stella.stamenova, labath, espindola

Reviewed By: jasonmolenda

Subscribers: leonid.mashinskiy, emaste, mgorny, aprantl, arichardson, MaskRay, lldb-commits, llvm-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D67347

llvm-svn: 374528

show more ...