Simplify some AsCString usage that was also explicitly handling default

Retrieve as StringRef since that's how it'll be used

Use StringRef to avoid unnecessary copies into std::strings

[lldb] Replace Host::SystemLog with Debugger::Report{Error,Warning}

As it exists today, Host::SystemLog is used exclusively for error
reporting. With the introduction of diagnostic events, we have a

[lldb] Replace Host::SystemLog with Debugger::Report{Error,Warning}

As it exists today, Host::SystemLog is used exclusively for error
reporting. With the introduction of diagnostic events, we have a better
way of reporting those. Instead of printing directly to stderr, these
messages now get printed to the debugger's error stream (when using the
default event handler). Alternatively, if someone is listening for these
events, they can decide how to display them, for example in the context
of an IDE such as Xcode.

This change also means we no longer write these messages to the system
log on Darwin. As far as I know, nobody is relying on this, but I think
this is something we could add to the diagnostic event mechanism.

Differential revision: https://reviews.llvm.org/D128480

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We don't require users to type out the full context of a function, for
symbol name matches. Instead, we extract the incoming path's base
name, look up all the symbols with that base name, and then co

We don't require users to type out the full context of a function, for
symbol name matches. Instead, we extract the incoming path's base
name, look up all the symbols with that base name, and then compare
the rest of the context that the user provided to make sure it
matches. However, we do this comparison using just a strstr. So for
instance:

break set -n foo::bar

will match not only "a::foo::bar" but "notherfoo::bar". The former is
pretty clearly the user's intent, but I don't think the latter is, and
results in breakpoints picking up too many matches.

This change adds a Language::DemangledNameContainsPath API which can
do a language aware match against the path provided. If the language
doesn't provide this we fall back to the strstr (though that's changed
to StringRef::contains in the patch).

Differential Revision: https://reviews.llvm.org/D124579

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Introduce new symbol on-demand for debug info

This diff introduces a new symbol on-demand which skips
loading a module's debug info unless explicitly asked on
demand. This provides significant perfo

Introduce new symbol on-demand for debug info

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

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[lldb] Port Process::PrintWarning* to use the new diagnostic events

Port the two Process::PrintWarning functions to use the new diagnostic
events through Debugger::ReportWarning. I kept the wrapper

[lldb] Port Process::PrintWarning* to use the new diagnostic events

Port the two Process::PrintWarning functions to use the new diagnostic
events through Debugger::ReportWarning. I kept the wrapper function in
the process, but delegated the work to the Module. Consistent with the
current code, the Module ensures the warning is only printed once per
module.

Differential revision: https://reviews.llvm.org/D123698

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[lldb] Change CreateMemoryInstance to take a WritableDataBuffer

Change the CreateMemoryInstance interface to take a WritableDataBuffer.

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

[LLDB] Applying clang-tidy modernize-use-default-member-init over LLDB

Applied modernize-use-default-member-init clang-tidy check over LLDB.
It appears in many files we had already switched to in cl

[LLDB] Applying clang-tidy modernize-use-default-member-init over LLDB

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

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[lldb] Move FindTypes scoped timer to SymbolFileDWARFDebugMap

[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.

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[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

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[lldb][NFC] clang-format some files as preparation for https://reviews.llvm.org/D114627

Reviewed By: werat

Differential Revision: https://reviews.llvm.org/D115110

[lldb] Remove some trivial scoped timers

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

[lldb] Remove some trivial scoped timers

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

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[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

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[lldb] Fix formatted log statement

Previously this would output literally without replacements

Differential Revision: https://reviews.llvm.org/D114178

[lldb][NFC] avoid unnecessary roundtrips between different string types

The amount of roundtrips between StringRefs, ConstStrings and std::strings is
getting a bit out of hand, this patch avoid the

[lldb][NFC] avoid unnecessary roundtrips between different string types

The amount of roundtrips between StringRefs, ConstStrings and std::strings is
getting a bit out of hand, this patch avoid the unnecessary roundtrips.

Reviewed By: wallace, aprantl

Differential Revision: https://reviews.llvm.org/D112863

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Revert "[lldb] Refactor Module::LookupInfo constructor"

This reverts commit cd2134e42aa7d1168a3ed54e41793b022f961b1f.

Seems like this broke some tests on arm and aarch64 boxes. Will
investigate bef

Revert "[lldb] Refactor Module::LookupInfo constructor"

This reverts commit cd2134e42aa7d1168a3ed54e41793b022f961b1f.

Seems like this broke some tests on arm and aarch64 boxes. Will
investigate before re-landing.

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[lldb] Refactor Module::LookupInfo constructor

Module::LookupInfo's constructor currently goes over supported languages
trying to figure out the best way to search for a symbol name. This
seems like

[lldb] Refactor Module::LookupInfo constructor

Module::LookupInfo's constructor currently goes over supported languages
trying to figure out the best way to search for a symbol name. This
seems like a great candidate for refactoring. Specifically, this is work
that can be delegated to language plugins.

Once again, the goal here is to further decouple plugins from
non-plugins. The idea is to have each language plugin take a name and
give you back some information about the name from the perspective of
the language. Specifically, each language now implements a
`GetFunctionNameInfo` method which returns an object of type
`Language::FunctionNameInfo`. Right now, it consists of a basename,
a context, and a FunctionNameType. Module::LookupInfo's constructor will
call `GetFunctionNameInfo` with the appropriate language plugin(s) and
then decide what to do with that information. I have attempted to maintain
existing behavior as best as possible.

A nice side effect of this change is that lldbCore no longer links
against the ObjC Language plugin.

Differential Revision: https://reviews.llvm.org/D108229

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[lldb] Use a struct to pass function search options to Module::FindFunction

Rather than passing two booleans around, which is especially error prone
with them being next to each other, use a struct

[lldb] Use a struct to pass function search options to Module::FindFunction

Rather than passing two booleans around, which is especially error prone
with them being next to each other, use a struct with named fields
instead.

Differential revision: https://reviews.llvm.org/D107295

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[lldb] Add the ability to silently import scripted commands

Add the ability to silence command script import. The motivation for
this change is being able to add command script import -s
lldb.macosx

[lldb] Add the ability to silently import scripted commands

Add the ability to silence command script import. The motivation for
this change is being able to add command script import -s
lldb.macosx.crashlog to your ~/.lldbinit without it printing the
following message at the beginning of every debug session.

"malloc_info", "ptr_refs", "cstr_refs", "find_variable", and
"objc_refs" commands have been installed, use the "--help" options on
these commands for detailed help.

In addition to forwarding the silent option to LoadScriptingModule, this
also changes ScriptInterpreterPythonImpl::ExecuteOneLineWithReturn and
ScriptInterpreterPythonImpl::ExecuteMultipleLines to honor the enable IO
option in ExecuteScriptOptions, which until now was ignored.

Note that IO is only enabled (or disabled) at the start of a session,
and for this particular use case, that's done when taking the Python
lock in LoadScriptingModule, which means that the changes to these two
functions are not strictly necessary, but (IMO) desirable nonetheless.

Differential revision: https://reviews.llvm.org/D105327

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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

Change PathMappingList::FindFile to return an optional result (NFC)

This is an NFC modernization refactoring that replaces the combination
of a bool return + reference argument, with an Optional ret

Change PathMappingList::FindFile to return an optional result (NFC)

This is an NFC modernization refactoring that replaces the combination
of a bool return + reference argument, with an Optional return value.

Differential Revision: https://reviews.llvm.org/D104405

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Change PathMappingList::RemapPath to return an optional result (NFC)

This is an NFC modernization refactoring that replaces the combination
of a bool return + reference argument, with an Optional re

Change PathMappingList::RemapPath to return an optional result (NFC)

This is an NFC modernization refactoring that replaces the combination
of a bool return + reference argument, with an Optional return value.

Differential Revision: https://reviews.llvm.org/D104404

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