This patch is rearranging code a bit to add WatchpointResources to
Process. A WatchpointResource is meant to represent a hardware
watchpoint register in the inferior process. It has an address, a size,
a type, and a list of Watchpoints that are using this
WatchpointResource.
This current patch doesn't add any of the features of
WatchpointResources that make them interesting -- a user asking to watch
a 24 byte object could watch this with three 8 byte WatchpointResources.
Or a Watchpoint on 1 byte at 0x1002 and a second watchpoint on 1 byte at
0x1003, these must both be served by a single WatchpointResource on that
doubleword at 0x1000 on a 64-bit target, if two hardware watchpoint
registers were used to track these separately, one of them may not be
hit. Or if you have one Watchpoint on a variable with a condition set,
and another Watchpoint on that same variable with a command defined or
different condition, or ignorecount, both of those Watchpoints need to
evaluate their criteria/commands when their WatchpointResource has been
hit.
There's a bit of code movement to rearrange things in the direction I'll
need for implementing this feature, so I want to start with reviewing &
landing this mostly NFC patch and we can focus on the algorithmic
choices about how WatchpointResources are shared and handled as they're
triggeed, separately.
This patch also stops printing "Watchpoint <n> hit: old value: <x>, new
vlaue: <y>" for Read watchpoints. I could make an argument for print
"Watchpoint <n> hit: current value <x>" but the current output doesn't
make any sense, and the user can print the value if they are
particularly interested. Read watchpoints are used primarily to
understand what code is reading a variable.
This patch adds more fallbacks for how to print the objects being
watched if we have types, instead of assuming they are all integral
values, so a struct will print its elements. As large watchpoints are
added, we'll be doing a lot more of those.
To track the WatchpointSP in the WatchpointResources, I changed the
internal API which took a WatchpointSP and devolved it to a Watchpoint*,
which meant touching several different Process files. I removed the
watchpoint code in ProcessKDP which only reported that watchpoints
aren't supported, the base class does that already.
I haven't yet changed how we receive a watchpoint to identify the
WatchpointResource responsible for the trigger, and identify all
Watchpoints that are using this Resource to evaluate their conditions
etc. This is the same work that a BreakpointSite needs to do when it has
been tiggered, where multiple Breakpoints may be at the same address.
There is not yet any printing of the Resources that a Watchpoint is
implemented in terms of ("watchpoint list", or
SBWatchpoint::GetDescription).
"watchpoint set var" and "watchpoint set expression" take a size
argument which was previously 1, 2, 4, or 8 (an enum). I've changed this
to an unsigned int. Most hardware implementations can only watch 1, 2,
4, 8 byte ranges, but with Resources we'll allow a user to ask for
different sized watchpoints and set them in hardware-expressble terms
soon.
I've annotated areas where I know there is work still needed with
LWP_TODO that I'll be working on once this is landed.
I've tested this on aarch64 macOS, aarch64 Linux, and Intel macOS.
https://discourse.llvm.org/t/rfc-large-watchpoint-support-in-lldb/72116
(cherry picked from commit fc6b72523f3d73b921690a713e97a433c96066c6)
...and follow ups.
As it has caused test failures on Linux Arm and AArch64:
https://lab.llvm.org/buildbot/#/builders/96/builds/49126https://lab.llvm.org/buildbot/#/builders/17/builds/45824
```
lldb-shell :: Subprocess/clone-follow-child-wp.test
lldb-shell :: Subprocess/fork-follow-child-wp.test
lldb-shell :: Subprocess/vfork-follow-child-wp.test
```
This reverts commit a6c62bf1a4717accc852463b664cd1012237d334,
commit a0a1ff3ab40e347589b4e27d8fd350c600526735 and commit
fc6b72523f3d73b921690a713e97a433c96066c6.
This patch is rearranging code a bit to add WatchpointResources to
Process. A WatchpointResource is meant to represent a hardware
watchpoint register in the inferior process. It has an address, a size,
a type, and a list of Watchpoints that are using this
WatchpointResource.
This current patch doesn't add any of the features of
WatchpointResources that make them interesting -- a user asking to watch
a 24 byte object could watch this with three 8 byte WatchpointResources.
Or a Watchpoint on 1 byte at 0x1002 and a second watchpoint on 1 byte at
0x1003, these must both be served by a single WatchpointResource on that
doubleword at 0x1000 on a 64-bit target, if two hardware watchpoint
registers were used to track these separately, one of them may not be
hit. Or if you have one Watchpoint on a variable with a condition set,
and another Watchpoint on that same variable with a command defined or
different condition, or ignorecount, both of those Watchpoints need to
evaluate their criteria/commands when their WatchpointResource has been
hit.
There's a bit of code movement to rearrange things in the direction I'll
need for implementing this feature, so I want to start with reviewing &
landing this mostly NFC patch and we can focus on the algorithmic
choices about how WatchpointResources are shared and handled as they're
triggeed, separately.
This patch also stops printing "Watchpoint <n> hit: old value: <x>, new
vlaue: <y>" for Read watchpoints. I could make an argument for print
"Watchpoint <n> hit: current value <x>" but the current output doesn't
make any sense, and the user can print the value if they are
particularly interested. Read watchpoints are used primarily to
understand what code is reading a variable.
This patch adds more fallbacks for how to print the objects being
watched if we have types, instead of assuming they are all integral
values, so a struct will print its elements. As large watchpoints are
added, we'll be doing a lot more of those.
To track the WatchpointSP in the WatchpointResources, I changed the
internal API which took a WatchpointSP and devolved it to a Watchpoint*,
which meant touching several different Process files. I removed the
watchpoint code in ProcessKDP which only reported that watchpoints
aren't supported, the base class does that already.
I haven't yet changed how we receive a watchpoint to identify the
WatchpointResource responsible for the trigger, and identify all
Watchpoints that are using this Resource to evaluate their conditions
etc. This is the same work that a BreakpointSite needs to do when it has
been tiggered, where multiple Breakpoints may be at the same address.
There is not yet any printing of the Resources that a Watchpoint is
implemented in terms of ("watchpoint list", or
SBWatchpoint::GetDescription).
"watchpoint set var" and "watchpoint set expression" take a size
argument which was previously 1, 2, 4, or 8 (an enum). I've changed this
to an unsigned int. Most hardware implementations can only watch 1, 2,
4, 8 byte ranges, but with Resources we'll allow a user to ask for
different sized watchpoints and set them in hardware-expressble terms
soon.
I've annotated areas where I know there is work still needed with
LWP_TODO that I'll be working on once this is landed.
I've tested this on aarch64 macOS, aarch64 Linux, and Intel macOS.
https://discourse.llvm.org/t/rfc-large-watchpoint-support-in-lldb/72116
Fixes [#68035](https://github.com/llvm/llvm-project/issues/68035), where
an inconsistency in the order of "Process launched" and "Process
stopped" messages occurs during `process launch`.
The fix involves adjusting the message output sequence in
`CommandObjectProcessLaunch::DoExecute` within
`source/Commands/CommandObjectProcess.cpp`. This ensures "Process
launched" consistently precedes "Process stopped" when executing
commands with the '-o' flag, i.e., non-interactive mode.
Upon implementing this change, two tests failed:
`lldb/test/Shell/Breakpoint/jit-loader_jitlink_elf.test` and
`lldb/test/Shell/Breakpoint/jit-loader_rtdyld_elf.test`. These failures
were expected as they relied on the previous, now-corrected message
order. Updating these tests to align with the new message sequence is
part of this PR's scope.
These error messages are written in a way that makes sense to an lldb
developer, but not to an end user who asks lldb to run on a compressed
corefile or whatever. Simplfy the messages.
This patch changes the interface of
StructuredData::Array::GetItemAtIndexAsString to return a
`std::optional<llvm::StringRef>` instead of taking an out parameter.
More generally, this commit serves as proposal that we change all of the
sibling APIs (`GetItemAtIndexAs`) to do the same thing. The reason this
isn't one giant patch is because it is rather unwieldy changing just one
of these, so if this is approved, I will do all of the other ones as
individual follow-ups.
This completes the conversion of LocateSymbolFile into a SymbolLocator
plugin. The only remaining function is DownloadSymbolFileAsync which
doesn't really fit into the plugin model, and therefore moves into the
SymbolLocator class, while still relying on the plugins to do the
underlying work.
This builds on top of the work started in c3a302d to convert
LocateSymbolFile to a SymbolLocator plugin. This commit moves
DownloadObjectAndSymbolFile.
Often, we only care about the split-dwarf files that have failed to
load. This can be useful when diagnosing binaries with many separate
debug info files where only some have errors.
```
(lldb) help image dump separate-debug-info
List the separate debug info symbol files for one or more target modules.
Syntax: target modules dump separate-debug-info <cmd-options> [<filename> [<filename> [...]]]
Command Options Usage:
target modules dump separate-debug-info [-ej] [<filename> [<filename> [...]]]
-e ( --errors-only )
Filter to show only debug info files with errors.
-j ( --json )
Output the details in JSON format.
This command takes options and free-form arguments. If your arguments
resemble option specifiers (i.e., they start with a - or --), you must use
' -- ' between the end of the command options and the beginning of the
arguments.
'image' is an abbreviation for 'target modules'
```
I updated the following tests
```
# on Linux
bin/lldb-dotest -p TestDumpDwo
# on Mac
bin/lldb-dotest -p TestDumpOso
```
This change applies to both the table and JSON outputs.
---------
Co-authored-by: Tom Yang <toyang@fb.com>
Add the ability to get a C++ vtable ValueObject from another
ValueObject.
This patch adds the ability to ask a ValueObject for a ValueObject that
represents the virtual function table for a C++ class. If the
ValueObject is not a C++ class with a vtable, a valid ValueObject value
will be returned that contains an appropriate error. If it is successful
a valid ValueObject that represents vtable will be returned. The
ValueObject that is returned will have a name that matches the demangled
value for a C++ vtable mangled name like "vtable for <class-name>". It
will have N children, one for each virtual function pointer. Each
child's value is the function pointer itself, the summary is the
symbolication of this function pointer, and the type will be a valid
function pointer from the debug info if there is debug information
corresponding to the virtual function pointer.
The vtable SBValue will have the following:
- SBValue::GetName() returns "vtable for <class>"
- SBValue::GetValue() returns a string representation of the vtable
address
- SBValue::GetSummary() returns NULL
- SBValue::GetType() returns a type appropriate for a uintptr_t type for
the current process
- SBValue::GetLoadAddress() returns the address of the vtable adderess
- SBValue::GetValueAsUnsigned(...) returns the vtable address
- SBValue::GetNumChildren() returns the number of virtual function
pointers in the vtable
- SBValue::GetChildAtIndex(...) returns a SBValue that represents a
virtual function pointer
The child SBValue objects that represent a virtual function pointer has
the following values:
- SBValue::GetName() returns "[%u]" where %u is the vtable function
pointer index
- SBValue::GetValue() returns a string representation of the virtual
function pointer
- SBValue::GetSummary() returns a symbolicated respresentation of the
virtual function pointer
- SBValue::GetType() returns the function prototype type if there is
debug info, or a generic funtion prototype if there is no debug info
- SBValue::GetLoadAddress() returns the address of the virtual function
pointer
- SBValue::GetValueAsUnsigned(...) returns the virtual function pointer
- SBValue::GetNumChildren() returns 0
- SBValue::GetChildAtIndex(...) returns invalid SBValue for any index
Examples of using this API via python:
```
(lldb) script vtable = lldb.frame.FindVariable("shape_ptr").GetVTable()
(lldb) script vtable
vtable for Shape = 0x0000000100004088 {
[0] = 0x0000000100003d20 a.out`Shape::~Shape() at main.cpp:3
[1] = 0x0000000100003e4c a.out`Shape::~Shape() at main.cpp:3
[2] = 0x0000000100003e7c a.out`Shape::area() at main.cpp:4
[3] = 0x0000000100003e3c a.out`Shape::optional() at main.cpp:7
}
(lldb) script c = vtable.GetChildAtIndex(0)
(lldb) script c
(void ()) [0] = 0x0000000100003d20 a.out`Shape::~Shape() at main.cpp:3
```
[lldb] Part 2 of 2 - Refactor `CommandObject::DoExecute(...)` to return
`void` instead of ~~`bool`~~
Justifications:
- The code doesn't ultimately apply the `true`/`false` return values.
- The methods already pass around a `CommandReturnObject`, typically
with a `result` parameter.
- Each command return object already contains:
- A more precise status
- The error code(s) that apply to that status
Part 1 refactors the `CommandObject::Execute(...)` method.
- See
[https://github.com/llvm/llvm-project/pull/69989](https://github.com/llvm/llvm-project/pull/69989)
rdar://117378957
[lldb] Part 1 of 2 - Refactor `CommandObject::Execute(...)` to return
`void` instead of ~~`bool`~~
Justifications:
- The code doesn't ultimately apply the `true`/`false` return values.
- The methods already pass around a `CommandReturnObject`, typically
with a `result` parameter.
- Each command return object already contains:
- A more precise status
- The error code(s) that apply to that status
Part 2 refactors the `CommandObject::DoExecute(...)` method.
- See
[https://github.com/llvm/llvm-project/pull/69991](https://github.com/llvm/llvm-project/pull/69991)
rdar://117378957
The `po` alias now matches the behavior of the `expression` command when
the it can apply a Fix-It to an expression.
Modifications
- Add has `m_fixed_expression` to the `CommandObjectDWIMPrint` class a
`protected` member that stores the post Fix-It expression, just like the
`CommandObjectExpression` class.
- Converted messages to present tense.
- Add test cases that confirms a Fix-It for a C++ expression for both
`po` and `expressions`
rdar://115317419
The `po` alias now matches the behavior of the `expression` command when
the it can apply a Fix-It to an expression.
Modifications
- Add has `m_fixed_expression` to the `CommandObjectDWIMPrint` class a
`protected` member that stores the post Fix-It expression, just like the
`CommandObjectExpression` class.
- Converted messages to present tense.
- Add test cases that confirms a Fix-It for a C++ expression for both
`po` and `expressions`
rdar://115317419
Co-authored-by: Pete Lawrence <plawrence@apple.com>
## Description
This pull request adds a new `stop-at-user-entry` option to LLDB
`process launch` command, allowing users to launch a process and pause
execution at the entry point of the program (for C-based languages,
`main` function).
## Motivation
This option provides a convenient way to begin debugging a program by
launching it and breaking at the desired entry point.
## Changes Made
- Added `stop-at-user-entry` option to `Options.td` and the
corresponding case in `CommandOptionsProcessLaunch.cpp` (short option is
'm')
- Implemented `GetUserEntryPointName` method in the Language plugins
available at the moment.
- Declared the `CreateBreakpointAtUserEntry` method in the Target API.
- Create Shell test for the command
`command-process-launch-user-entry.test`.
## Usage
`process launch --stop-at-user-entry` or `process launch -m` launches
the process and pauses execution at the entry point of the program.
Prior to this the command would simply crash when run on a running
process.
Of the three register commands, "info" was the only one missing these
requirements. On some level it makes sense because you're not going to
read a value or modify anything, but practically I think lldb assumes
any time you're going to access register related stuff, the process
should be paused.
I noticed this debugging with a remote gdb stub, so I've recreated that
scenario using attach in a new test case.
`watch set expression` was passing the OptionGroupWatchpoint enum
in to Target where the LLDB_WATCH_TYPE_* bitfield was expected.
Modify matched READ|WRITE and resulted in a test failure in
TestWatchTaggedAddress.py. David temporarily changed the test to
expect this incorrect output; this fixes the bug and updates the
test case to test it for correctness again.
This reverts commit a7b78cac9a77e3ef6bbbd8ab1a559891dc693401.
With updates to the tests.
TestWatchTaggedAddress.py: Updated the expected watchpoint types,
though I'm not sure there should be a differnt default for the two
ways of setting them, that needs to be confirmed.
TestStepOverWatchpoint.py: Skipped this everywhere because I think
what used to happen is you couldn't put 2 watchpoints on the same
address (after alignment). I guess that this is now allowed because
modify watchpoints aren't accounted for, but likely should be.
Needs investigating.
This reverts commit 933ad5c897ee366759a54869b35b2d7285a92137.
This caused 1 test failure and an unexpected pass on AArch64 Linux:
https://lab.llvm.org/buildbot/#/builders/96/builds/45765
Wasn't reported because the bot was already red at the time.
Watchpoints in lldb can be either 'read', 'write', or 'read/write'. This
is exposing the actual behavior of hardware watchpoints. gdb has a
different behavior: a "write" type watchpoint only stops when the
watched memory region *changes*.
A user is using a watchpoint for one of three reasons:
1. Want to find what is changing/corrupting this memory.
2. Want to find what is writing to this memory.
3. Want to find what is reading from this memory.
I believe (1) is the most common use case for watchpoints, and it
currently can't be done in lldb -- the user needs to continue every time
the same value is written to the watched-memory manually. I think gdb's
behavior is the correct one. There are some use cases where a developer
wants to find every function that writes/reads to/from a memory region,
regardless of value, I want to still allow that functionality.
This is also a bit of groundwork for my large watchpoint support
proposal
https://discourse.llvm.org/t/rfc-large-watchpoint-support-in-lldb/72116
where I will be adding support for AArch64 MASK watchpoints which watch
power-of-2 memory regions. A user might ask to watch 24 bytes, and a
MASK watchpoint stub can do this with a 32-byte MASK watchpoint if it is
properly aligned. And we need to ignore writes to the final 8 bytes of
that watched region, and not show those hits to the user.
This patch adds a new 'modify' watchpoint type and it is the default.
Re-landing this patch after addressing testsuite failures found in CI on
Linux, Intel machines, and windows.
rdar://108234227
Watchpoints in lldb can be either 'read', 'write', or 'read/write'. This
is exposing the actual behavior of hardware watchpoints. gdb has a
different behavior: a "write" type watchpoint only stops when the
watched memory region *changes*.
A user is using a watchpoint for one of three reasons:
1. Want to find what is changing/corrupting this memory.
2. Want to find what is writing to this memory.
3. Want to find what is reading from this memory.
I believe (1) is the most common use case for watchpoints, and it
currently can't be done in lldb -- the user needs to continue every time
the same value is written to the watched-memory manually. I think gdb's
behavior is the correct one. There are some use cases where a developer
wants to find every function that writes/reads to/from a memory region,
regardless of value, I want to still allow that functionality.
This is also a bit of groundwork for my large watchpoint support
proposal
https://discourse.llvm.org/t/rfc-large-watchpoint-support-in-lldb/72116
where I will be adding support for AArch64 MASK watchpoints which watch
power-of-2 memory regions. A user might ask to watch 24 bytes, and a
MASK watchpoint stub can do this with a 32-byte MASK watchpoint if it is
properly aligned. And we need to ignore writes to the final 8 bytes of
that watched region, and not show those hits to the user.
This patch adds a new 'modify' watchpoint type and it is the default.
rdar://108234227
This already applies to enable and disable, delete was missing
a check.
This cannot be tested properly with the current completion tests,
but it will be when I make them more strict in a follow up patch.
- Allow the definition of synthetic formatters in C++ even when LLDB is built without python scripting support.
- Fix linking problems with the CXXSyntheticChildren
Differential Revision: https://reviews.llvm.org/D158010
Lots of users use "po" as their default print command. If the type
doesn't implement the description function the output is often not what
the user wants. Print a hint telling the user that they might prefer
using "p" instead.
Differential Revision: https://reviews.llvm.org/D153489
Currently frame var --regex sometimes searches globals, sometimes it doesn't.
This happens because `StackFrame::GetVariableList` always returns the biggest
list it has, regardless of whether only globals were requested or not. In other
words, if a previous call to `GetVariableList` requested globals, all subsequent
calls will see them.
The implication here is that users of `StackFrame::GetVariableList` are expected
to filter the results of this function. This is what we do for a vanilla
`frame var` command. But it is not what we do when `--regex` is used. This
commit solves the issue by:
1. Making `--regex` imply `--globals`. This matches the behavior of `frame var
<some_name>`, which will also search the global scope.
2. Making the `--regex` search respect the command object options.
See the added test for an example of the oddities this patch addresses. Without
the patch, the test fails. However it could be made to pass by calling a plain
`frame var` before calling `frame var --regex A::`.
Differential Revision: https://reviews.llvm.org/D155334
These methods all take a `Stream *` to get feedback about what's going
on. By default, it's a nullptr, but we always feed it with a valid
pointer. It would therefore make more sense to have this take a
reference.
Differential Revision: https://reviews.llvm.org/D154883
Fix a crash when trying to complete an ambiguous subcommand. Take `set s
tar` for example: for the subcommand `s` there's ambiguity between set
and show. Pressing TAB after this input currently crashes LLDB. The
problem is that we're trying to complete `tar` but give up at `s`
because of the ambiguity. LLDB doesn't expect the completed string to be
shorter than the current string and crashes when trying to eliminate the
common prefix.
rdar://111848598
Differential revision: https://reviews.llvm.org/D154643
Also, make it possible for new Targets which haven't been added to
the TargetList yet to check for interruption, and add a few more
places in building modules where we can check for interruption.
Differential Revision: https://reviews.llvm.org/D154542
Previously the following would crash:
(lldb) run
Process 2594053 launched: '/tmp/test.o' (aarch64)
Process 2594053 exited with status = 0 (0x00000000)
(lldb) register read <tab>
As the completer assumed that the execution context would always
have a register context. After a program has finished, it does not.
Split out the generic parts of the test from the x86 specific tests,
and added "register info" to both.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D154413
We recently saw an uptick in internal reports complaining that LLDB is
slow when sources on network file systems are inaccessible. I looked at
the SourceManger and its cache and I think there’s some room for
improvement in terms of reducing file system accesses:
1. We always resolve the path.
2. We always check the timestamp.
3. We always recheck the file system for negative cache hits.
D153726 fixes (1) but (2) and (3) are necessary because of the cache’s
current design. Source files are cached at the debugger level which
means that the source file cache can span multiple targets and
processes. It wouldn't be correct to not reload a modified or new file
from disk.
We can however significantly reduce the number of file system accesses
by using a two level cache design: one cache at the debugger level and
one at the process level:
- The cache at the debugger level works the way it does today. There is
no negative cache: if we can't find the file on disk, we'll try again
next time the cache is queried. If a cached file's timestamp changes
or if its path remapping changes, the cached file is evicted and we
reload it from disk.
- The cache at the process level is design to avoid accessing the file
system. It doesn't check the file's modification time. It caches
negative results, so if a file didn't exist, it doesn't try to reread
it from disk. Checking if the path remapping changed is cheap
(doesn't involve checking the file system) and is the only way for a
file to get evicted from the process cache.
The result of this patch is that LLDB will not show you new content if a
file is modified or created while a process is running. I would argue
that this is what most people would expect, but it is a change from how
LLDB behaves today.
For an average stop, we query the source cache 4 times. With the current
implementation, that's 4 stats to get the modification time, If the file
doesn't exist on disk, that's an additional 4 stats. Before D153726, if
the path starts with a ~ there are another additional 4 calls to
realpath. When debugging sources on a slow (network) file system, this
quickly adds up.
In addition to the two level caching, this patch also adds a source
logging channel and synchronization to the source file cache. The
logging was helpful during development and hopefully will help us triage
issues in the future. The synchronization isn't a new requirement: as
the cache is shared across targets, there is no guarantees that it can't
be accessed concurrently. The patch also fixes a bug where we would only
set the source remapping ID if the un-remapped file didn't exist, which
led to the file getting evicted from the cache on every access.
rdar://110787562
Differential revision: https://reviews.llvm.org/D153834
This reverts commit 3254623d73fb7252385817d8057640c9d5d5ffd1.
One test has been updated to add the "-s" flag which along with
86fd957af981f146a306831608d7ad2de65b9560 should fix the tests on MacOS.
An assert on hijack listener added in that patch was removed, it seems
to be correct on MacOS but not on Linux.
Fix `platform process launch` on macOS where it fails for lack of auto-resuming support.
This change reproduces the resuming logic found in `Target::Launch`.
This issue was identified by @DavidSpickett in D153636. This change relies on the tests
added in that PR. Thanks David.
Differential Revision: https://reviews.llvm.org/D153922
This fixes#62068.
After 8d1de7b34af46a089eb5433c700419ad9b2923ee the following issue appeared:
```
$ ./bin/lldb /tmp/test.o
(lldb) target create "/tmp/test.o"
Current executable set to '/tmp/test.o' (aarch64).
(lldb) platform process launch -s
error: Cannot launch '': Nothing to launch
```
Previously would call target->GetRunArguments when there were no extra
arguments, so we could find out what target.run-args might be.
Once that change started relying on the first arg being the exe,
the fact that that call clears the existing argument list caused the bug.
Instead, have it set a local arg list and append that to the existing
one. Which in this case will just contain the exe name.
Since there's no existing tests for this command I've added a new file
that covers enough to check this issue.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D153636
Add two new source subcommands: source cache dump and source cache
clear. As the name implies the first one dumps the source cache while
the later clears the cache.
This patch was motivated by a handful of (internal) bug reports related
to sources not being available. Right now those issues can be hard to
diagnose. The new commands give users, as well as us as developers, more
insight into and control over the source cache.
Differential revision: https://reviews.llvm.org/D153685
