On macOS, LLDB uses the DebugSymbols.framework to locate symbol rich
dSYM bundles. [1] The framework uses a variety of methods, one of them
calling into a binary or shell script to locate (and download) dSYMs.
Internally at Apple, that tool is called dsymForUUID and for simplicity
I'm just going to refer to it that way here too, even though it can be
be an arbitrary executable.
The most common use case for dsymForUUID is to fetch symbols from the
network. This can take a long time, and because the calls to the
DebugSymbols.framework are blocking, it takes a while to launch the
process. This is expected and therefore many people don't use this
functionality, but instead use add-dsym when they want symbols for a
given frame, backtrace or module. This is a little faster because you're
only fetching symbols for the module you care about, but it's still a
slow, blocking operation.
This patch introduces a hybrid approach between the two. When
symbols.enable-background-lookup is enabled, lldb will do the equivalent
of add-dsym in the background for every module that shows up in the
backtrace but doesn't have symbols for. From the user's perspective
there is no slowdown, because the process launches immediately, with
whatever symbols are available. Meanwhile, more symbol information is
added over time as the background fetching completes.
[1] https://lldb.llvm.org/use/symbols.html
rdar://76241471
Differential revision: https://reviews.llvm.org/D131328
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
Add a setting to change how progress is shown in a color enabled
terminal. This follows the existing -prefix, -suffix pattern
that's used elsewhere in lldb.
Differential revision: https://reviews.llvm.org/D121062
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
I'm a big fan of the autosuggestion feature but my terminal/color scheme
doesn't display faint any differently than regular lldb output, which
makes the feature a little confusing. This patch add a setting to change
the autosuggestion ANSI escape codes.
For example, to display the autosuggestion in italic, you can add this
to your ~/.lldbinit
settings set show-autosuggestion-ansi-prefix ${ansi.italic}
setting set show-autosuggestion-ansi-suffix ${ansi.normal}
Differential revision: https://reviews.llvm.org/D121064
Until the introduction of the C++ REPL, there was always a single REPL
language. Several places relied on this assumption through
repl_languages.GetSingularLanguage. Now that this is no longer the case,
we need a way to specify a selected/preferred REPL language. This patch
does that with the help of a debugger property, taking inspiration from
how we store the scripting language.
Differential revision: https://reviews.llvm.org/D116697
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
This patch replaces the static large function threshold variable with a
global debugger setting (`stop-disassembly-max-size`).
The default threshold is now set to 32KB (instead of 8KB) and can be modified.
rdar://74726362
Differential Revision: https://reviews.llvm.org/D97486
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
This is relanding D81001. The patch originally failed as on newer editline
versions it seems CC_REFRESH will move the cursor to the start of the line via
\r and then back to the original position. On older editline versions like
the one used by default on macOS, CC_REFRESH doesn't move the cursor at all.
As the patch changed the way we handle tab completion (previously we did
REDISPLAY but now we're doing CC_REFRESH), this caused a few completion tests
to receive this unexpected cursor movement in the output stream.
This patch updates those tests to also accept output that contains the specific
cursor movement commands (\r and then \x1b[XC). lldbpexpect.py received an
utility method for generating the cursor movement escape sequence.
Original summary:
I implemented autosuggestion if there is one possible suggestion.
I set the keybinds for every character. When a character is typed, Editline::TypedCharacter is called.
Then, autosuggestion part is displayed in gray, and you can actually input by typing C-k.
Editline::Autosuggest is a function for finding completion, and it is like Editline::TabCommand now, but I will add more features to it.
Testing does not work well in my environment, so I can't confirm that it goes well, sorry. I am dealing with it now.
Reviewed By: teemperor, JDevlieghere, #lldb
Differential Revision: https://reviews.llvm.org/D81001
This reverts commit 246afe0cd1. This broke
the following tests on Linux it seems:
lldb-api :: commands/expression/multiline-completion/TestMultilineCompletion.py
lldb-api :: iohandler/completion/TestIOHandlerCompletion.py
I implemented autosuggestion if there is one possible suggestion.
I set the keybinds for every character. When a character is typed, Editline::TypedCharacter is called.
Then, autosuggestion part is displayed in gray, and you can actually input by typing C-k.
Editline::Autosuggest is a function for finding completion, and it is like Editline::TabCommand now, but I will add more features to it.
Testing does not work well in my environment, so I can't confirm that it goes well, sorry. I am dealing with it now.
Reviewed By: teemperor, JDevlieghere, #lldb
Differential Revision: https://reviews.llvm.org/D81001
Summary:
LLDB memory-maps large source files, and at the same time, caches
all source files in the Source Cache.
On Windows, memory-mapped source files are not writeable, causing
bad user experience in IDEs (such as errors when saving edited files).
IDEs should have the ability to disable the Source Cache at LLDB
startup, so that users can edit source files while debugging.
Bug: llvm.org/PR45310
Reviewers: labath, JDevlieghere, jingham
Reviewed By: labath
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D76804
Highlight the color marker similar to what we do for the column marker.
The default color matches the color of the current PC marker (->) in the
default disassembly format.
Differential revision: https://reviews.llvm.org/D75070
Summary:
This code is handling debug info paths starting with /proc/self/cwd,
which is one of the mechanisms people use to obtain "relocatable" debug
info (the idea being that one starts the debugger with an appropriate
cwd and things "just work").
Instead of resolving the symlinks inside DWARFUnit, we can do the same
thing more elegantly by hooking into the existing Module path remapping
code. Since llvm::DWARFUnit does not support any similar functionality,
doing things this way is also a step towards unifying llvm and lldb
dwarf parsers.
Reviewers: JDevlieghere, aprantl, clayborg, jdoerfert
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D71770
Summary:
This is a bit more explicit, and makes it possible to build LLDB without
varying the -I lines per-directory.
(The latter is useful because many build systems only allow this to be
configured per-library, and LLDB is insufficiently layered to be split into
multiple libraries on stricter build systems).
(My comment on D65185 has some more context)
Reviewers: JDevlieghere, labath, chandlerc, jdoerfert
Reviewed By: labath
Subscribers: mgorny, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D65397
Patch by Sam McCall!
llvm-svn: 367241
Jonas Devlieghere