Commit Graph

674 Commits

Author SHA1 Message Date
Pavel Labath e588b8b664 DWARFExpression: Simplify class interface
Summary:
The DWARFExpression methods have a lot of arguments. This removes two of
them by removing the ability to slice the expression via two offset+size
parameters. This is a functionality that it is not always needed, and
when it is, we already have a different handy way of slicing a data
extractor which we can use instead.

Reviewers: JDevlieghere, clayborg

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D66745

llvm-svn: 370027
2019-08-27 07:49:41 +00:00
Pavel Labath b54efd28c4 Move ProcessInstanceInfoTest to Utility
The class under test was moved in r355342. This moves the test code too.

llvm-svn: 369907
2019-08-26 13:07:02 +00:00
Pavel Labath 602f29fd7c ProcessInstanceInfo: Fix dumping of invalid user ids
Don't attempt to print invalid user ids. Previously, these would come
out as UINT32_MAX, or as an assertion failure.

llvm-svn: 369906
2019-08-26 13:03:21 +00:00
Pavel Labath f899bf135f Fix windows build after r369894
Constructing a std::vector from a llvm::map_range fails on windows,
apparently because std::vector expects the input iterator to have a
const operator* (map_range iterator has a non-const one).

This avoids the cleverness and unrolls the map-loop manually (which is
also slightly shorter).

llvm-svn: 369905
2019-08-26 12:42:32 +00:00
Pavel Labath c7deb7f808 Postfix: move more code out of the PDB plugin
Summary:
Previously we moved the code which parses a single expression out of the PDB
plugin, because that was useful for DWARF expressions in breakpad. However, FPO
programs are used in breakpad files too (when unwinding on windows), so this
completes the job, and moves the rest of the FPO parser too.

Reviewers: amccarth, aleksandr.urakov

Subscribers: aprantl, markmentovai, rnk, lldb-commits

Differential Revision: https://reviews.llvm.org/D66634

llvm-svn: 369894
2019-08-26 11:44:14 +00:00
Pavel Labath 0a9f47d7cc Breakpad: Add support for parsing STACK WIN records
Summary: The fields that aren't useful for us right now are simply ignored.

Reviewers: amccarth, markmentovai

Subscribers: rnk, lldb-commits

Differential Revision: https://reviews.llvm.org/D66633

llvm-svn: 369892
2019-08-26 11:25:28 +00:00
Raphael Isemann ae34ed2c0d [lldb][NFC] Remove WordComplete mode, make result array indexed from 0 and remove any undocumented/redundant return values
Summary:
We still have some leftovers of the old completion API in the internals of
LLDB that haven't been replaced by the new CompletionRequest. These leftovers
are:

* The return values (int/size_t) in all completion functions.
* Our result array that starts indexing at 1.
* `WordComplete` mode.

I didn't replace them back then because it's tricky to figure out what exactly they
are used for and the completion code is relatively untested. I finally got around
to writing more tests for the API and understanding the semantics, so I think it's
a good time to get rid of them.

A few words why those things should be removed/replaced:

* The return values are really cryptic, partly redundant and rarely documented.
  They are also completely ignored by Xcode, so whatever information they contain will end up
  breaking Xcode's completion mechanism. They are also partly impossible to even implement
  as we assign negative values special meaning and our completion API sometimes returns size_t.

  Completion functions are supposed to return -2 to rewrite the current line. We seem to use this
  in some untested code path to expand the history repeat character to the full command, but
  I haven't figured out why that doesn't work at the moment.
  Completion functions return -1 to 'insert the completion character', but that isn't implemented
  (even though we seem to activate this feature in LLDB sometimes).
  All positive values have to match the number of results. This is obviously just redundant information
  as the user can just look at the result list to get that information (which is what Xcode does).

* The result array that starts indexing at 1 is obviously unexpected. The first element of the array is
  reserved for the common prefix of all completions (e.g. "foobar" and "footar" -> "foo"). The idea is
  that we calculate this to make the life of the API caller easier, but obviously forcing people to have
  1-based indices is not helpful (or even worse, forces them to manually copy the results to make it
  0-based like Xcode has to do).

* The `WordComplete` mode indicates that LLDB should enter a space behind the completion. The
  idea is that we let the top-level API know that we just provided a full completion. Interestingly we
  `WordComplete` is just a single bool that somehow represents all N completions. And we always
  provide full completions in LLDB, so in theory it should always be true.
  The only use it currently serves is providing redundant information about whether we have a single
  definitive completion or not (which we already know from the number of results we get).

This patch essentially removes `WordComplete` mode and makes the result array indexed from 0.
It also removes all return values from all internal completion functions. The only non-redundant information
they contain is about rewriting the current line (which is broken), so that functionality was moved
to the CompletionRequest API. So you can now do `addCompletion("blub", "description", CompletionMode::RewriteLine)`
to do the same.

For the SB API we emulate the old behaviour by making the array indexed from 1 again with the common
prefix at index 0. I didn't keep the special negative return codes as we either never sent them before (e.g. -2) or we
didn't even implement them in the Editline handler (e.g. -1).

I tried to keep this patch minimal and I'm aware we can probably now even further simplify a bunch of related code,
but I would prefer doing this in follow-up NFC commits

Reviewers: JDevlieghere

Reviewed By: JDevlieghere

Subscribers: arphaman, abidh, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D66536

llvm-svn: 369624
2019-08-22 07:41:23 +00:00
Adrian Prantl 330ae19a1a Generalize FindTypes with CompilerContext to support fuzzy lookup
This patch generalizes the FindTypes with CompilerContext interface to
support looking up a type of unknown kind by name, as well as looking
up a type inside an unspecified submodule. These features are
motivated by the Swift branch, but are fully tested via unit tests and
lldb-test on llvm.org.  Specifically, this patch adds an AnyModule and
an AnyType CompilerContext kind.

Differential Revision: https://reviews.llvm.org/D66507

rdar://problem/54471165

llvm-svn: 369555
2019-08-21 18:06:56 +00:00
Pavel Labath dc5403d2dc Properly EXCLUDE_FROM_ALL the testing support library
The EXCLUDE_FROM_ALL variable is used by add_llvm_library, but lldb does
not use that function (it uses llvm_add_library :P). Instead, set the directory
property with the same name directly.

This should fix standalone builds against an llvm install tree.

llvm-svn: 369502
2019-08-21 08:21:51 +00:00
Jonas Devlieghere d35b42f20a [NFC] Return llvm::StringRef from StringExtractor::GetStringRef.
This patch removes the two variant of StringExtractor::GetStringRef that
return (non-)const references to std::string. The non-const one was
being abused to reinitialize the StringExtractor and its uses are
replaced by calls to the copy asignment operator. The const variant was
refactored to return an actual llvm::StringRef.

llvm-svn: 369493
2019-08-21 04:55:56 +00:00
Jonas Devlieghere 4b3c0fd5da [NFC] Remove lldb_utility namespace.
While generating the Doxygen I noticed this lone namespace that has one
class and one function in it. This moves them into lldb_private.

llvm-svn: 369485
2019-08-21 00:50:46 +00:00
Pavel Labath 028fe5af60 Fix build for r369374
This patch added some gtest code to the TestingSupport library. As this
is not a unit test, but a unit test library, gtest does not get added to
the include path automatically, but we have to do that ourselves. (It
was working for me without this because the compiler picked up the
system gtest instead.)

llvm-svn: 369381
2019-08-20 13:17:20 +00:00
Pavel Labath 5877fb7cd7 Convert minidump unittests to use llvm::yaml::convertYAML
previously they used a minidump-specific function for this purpose, but
this is no longer needed now that whole of yaml2obj is available as a
library.

llvm-svn: 369379
2019-08-20 12:53:42 +00:00
Pavel Labath a2e270fa70 unittests: Use yaml2obj as a library instead of an external process
Summary:
Recently, yaml2obj has been turned into a library. This means we can use
it from our unit tests directly, instead of shelling out to an external
process. This patch does just that.

Reviewers: JDevlieghere, aadsm, espindola, jdoerfert

Subscribers: emaste, mgorny, arichardson, MaskRay, jhenderson, abrachet, lldb-commits

Differential Revision: https://reviews.llvm.org/D65949

llvm-svn: 369374
2019-08-20 12:28:36 +00:00
Raphael Isemann 6632ad5851 [lldb][NFC] Stop using GetNumberOfMatches in CompletionRequest test
This function is just a wrapper for GetNumberOfResults and will
be removed soon. This patch just changes all calls to GetNumberOfResults
where possible (which is currently just the unit test).

llvm-svn: 369267
2019-08-19 14:52:48 +00:00
Raphael Isemann 21599876be [lldb][NFC] Address review comments to StringList for-loop support
llvm-svn: 369237
2019-08-19 07:22:19 +00:00
Jonas Devlieghere 3af3f1e8e2 [Utility] Reimplement RegularExpression on top of llvm::Regex
Originally I wanted to remove the RegularExpression class in Utility and
replace it with llvm::Regex. However, during that transition I noticed
that there are several places where need the regular expression string.
So instead I propose to keep the RegularExpression class and make it a
thin wrapper around llvm::Regex.

This patch also removes the workaround for empty regular expressions.
The result is that we are now (more or less) POSIX conformant.

Differential revision: https://reviews.llvm.org/D66174

llvm-svn: 369153
2019-08-16 21:25:36 +00:00
Raphael Isemann 4c78b78825 [lldb][NFC] Allow for-ranges on StringList
llvm-svn: 369113
2019-08-16 14:27:35 +00:00
Aaron Smith 5032c6ea08 [lldb-server] Disable a test on Windows until it can be fixed
llvm-svn: 369083
2019-08-16 03:49:41 +00:00
Jonas Devlieghere a8f3ae7c9c [LLDB] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

Differential revision: https://reviews.llvm.org/D66259

llvm-svn: 368933
2019-08-14 22:19:23 +00:00
Aaron Smith 5146a9ea5d Initial support for native debugging of x86/x64 Windows processes
Summary: Thanks to Hui Huang and the reviewers for all the help with this patch.

Reviewers: labath, Hui, jfb, clayborg, amccarth

Reviewed By: labath

Subscribers: amccarth, compnerd, dexonsmith, mgorny, jfb, teemperor, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D63165

llvm-svn: 368759
2019-08-13 22:18:01 +00:00
Alex Langford bddab07d4a [Symbol] Decouple clang from CompilerType
Summary:
Ideally CompilerType would have no knowledge of clang or any individual
TypeSystem. Decoupling clang is relatively straightforward.

Differential Revision: https://reviews.llvm.org/D66102

llvm-svn: 368741
2019-08-13 19:40:36 +00:00
Raphael Isemann 5028654214 [lldb][NFC] Add unit test for lldb_private::DiagnosticManager
llvm-svn: 368567
2019-08-12 13:31:45 +00:00
Pavel Labath 88c77d6752 ObjectFileELF: Convert a unit test to a lit test
It is much easier to test this functionality via lldb-test.

llvm-svn: 368289
2019-08-08 12:57:46 +00:00
Pavel Labath 6db975b7b8 Add a missing include to SymbolFilePDBTests.cpp
This should _really_ fix the pdb unit tests.

llvm-svn: 368271
2019-08-08 09:43:20 +00:00
Pavel Labath 959e603456 Fix PDB unit tests for the GetSymbolVendor deletion
llvm-svn: 368265
2019-08-08 08:22:26 +00:00
Jonas Devlieghere af0c828a1e [ExecutionContext] Return the target/process byte order.
Currently ExecutionContext::GetByteOrder() always returns the host byte
order. This seems like a simple mistake: the return keyword appears to
have been omitted by accident. This patch fixes that and adds a unit
test.

Bugreport: https://llvm.org/PR37950

Differential revision: https://reviews.llvm.org/D48704

llvm-svn: 368181
2019-08-07 16:09:35 +00:00
Pavel Labath 465eae3669 SymbolVendor: Remove passthrough methods
After the recent refactorings the SymbolVendor passthrough no longer
serve any purpose. This patch removes those methods, and updates all
callsites to go to the symbol file directly -- in most cases that just
means calling GetSymbolFile()->foo() instead of
GetSymbolVendor()->foo().

llvm-svn: 368001
2019-08-06 09:12:42 +00:00
Pavel Labath 3a3ca963be Add missing includes to SymbolFilePDBTests
These became needed after r367368.

llvm-svn: 367410
2019-07-31 11:31:05 +00:00
Jonas Devlieghere b22860da61 [CompletionRequest] Remove unimplemented members.
Completion requests have two fields that are essentially unimplemented:
`m_match_start_point` and `m_max_return_elements`. This would've been
okay, if it wasn't for the fact that this caused a bunch of useless
parameters to be passed around. Occasionally there would be a comment or
assert saying that they are not supported. This patch removes them.

llvm-svn: 367385
2019-07-31 03:48:29 +00:00
Jonas Devlieghere 175f093090 [StringList] Change LongestCommonPrefix API
When investigating a completion bug I got confused by the API.
LongestCommonPrefix finds the longest common prefix of the strings in
the string list. Instead of returning that string through an output
argument, just return it by value.

llvm-svn: 367384
2019-07-31 03:26:10 +00:00
Alex Langford c1210c7e96 [SymbolFilePDB] Fix windows bots after rL367360
SymbolFilePDB tests were using GetTypeSystemForLanguage but weren't
changed to accomodate the use of an llvm::Expected. I adjusted them
accordingly.

llvm-svn: 367368
2019-07-30 23:48:03 +00:00
Pavel Labath 84a6856928 SymbolVendor: Move Symtab construction into the SymbolFile
Summary:
Instead of having SymbolVendor coordinate Symtab construction between
Symbol and Object files, make the SymbolVendor function a passthrough,
and put all of the logic into the SymbolFile.

Reviewers: clayborg, JDevlieghere, jingham, espindola

Subscribers: emaste, mgorny, arichardson, MaskRay, lldb-commits

Differential Revision: https://reviews.llvm.org/D65208

llvm-svn: 367086
2019-07-26 07:03:28 +00:00
Alex Lorenz 86814bf658 [Support] move FileCollector from LLDB to llvm/Support
The file collector class is useful for creating reproducers,
not just for LLDB, but for other tools as well in LLVM/Clang.

Differential Revision: https://reviews.llvm.org/D65237

llvm-svn: 366956
2019-07-24 22:59:20 +00:00
Jonas Devlieghere 63e5fb76ec [Logging] Replace Log::Printf with LLDB_LOG macro (NFC)
This patch replaces explicit calls to log::Printf with the new LLDB_LOGF
macro. The macro is similar to LLDB_LOG but supports printf-style format
strings, instead of formatv-style format strings.

So instead of writing:

  if (log)
    log->Printf("%s\n", str);

You'd write:

  LLDB_LOG(log, "%s\n", str);

This change was done mechanically with the command below. I replaced the
spurious if-checks with vim, since I know how to do multi-line
replacements with it.

  find . -type f -name '*.cpp' -exec \
  sed -i '' -E 's/log->Printf\(/LLDB_LOGF\(log, /g' "{}" +

Differential revision: https://reviews.llvm.org/D65128

llvm-svn: 366936
2019-07-24 17:56:10 +00:00
Antonio Afonso 70795c1e3a Revert "Revert "Add ReadCStringFromMemory for faster string reads""
This reverts commit 9c10b620c0.

llvm-svn: 366848
2019-07-23 20:40:37 +00:00
Stefan Granitz fc0d766511 [CMake] Align debugserver with lldb-server on Darwin
Summary: Make debugserver a tool like lldb-server, so it can be included/excluded via `LLDB_TOOL_DEBUGSERVER_BUILD`. This replaces the old `LLDB_NO_DEBUGSERVER` flag. Doing the same for darwin-debug while I am here.

Reviewers: xiaobai, JDevlieghere, davide

Reviewed By: xiaobai, JDevlieghere

Subscribers: mgorny, lldb-commits, #lldb

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D64994

llvm-svn: 366631
2019-07-20 11:18:31 +00:00
Jonas Devlieghere 37fed66402 [LLDB] Remove lldb-mi
As discussed on the mailing list [1], this patch removes the lldb-mi
tool and its tests from the LLDB repository. We moved lldb-mi into a
separate repository on GitHub [2] for downstream users or maintainers to
build and package.

[1] http://lists.llvm.org/pipermail/lldb-dev/2019-July/015103.html
[2] https://github.com/lldb-tools/lldb-mi

Differential revision: https://reviews.llvm.org/D64255

llvm-svn: 366465
2019-07-18 17:06:06 +00:00
Stefan Granitz 0c4948455d [CMake] Always build debugserver on Darwin and allow tests to use the system's one
Summary:
We can always build debugserver, but we can't always sign it to be useable for testing. `LLDB_USE_SYSTEM_DEBUGSERVER` should only tell whether or not the system debugserver should be used for testing.
The old behavior complicated the logic around debugserver a lot. The new logic sorts out most of it.

Please note that this patch is in early stage and needs some more testing. It should not affect platfroms other than Darwin. It builds on Davide's approach to validate the code-signing identity at configuration time.

What do you think?

Reviewers: xiaobai, JDevlieghere, davide, compnerd, friss, labath, mgorny, jasonmolenda

Reviewed By: JDevlieghere

Subscribers: lldb-commits, #lldb

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D64806

llvm-svn: 366433
2019-07-18 13:30:37 +00:00
Adrian Prantl 3b4a667854 Add a sanity check to the domain socket tests.
rdar://problem/52062631

llvm-svn: 364562
2019-06-27 16:45:23 +00:00
Antonio Afonso 9c10b620c0 Revert "Add ReadCStringFromMemory for faster string reads"
This reverts commit a7335393f5.

It seems this is breaking a bunch of tests (https://reviews.llvm.org/D62503#1549874) so reverting until I find the time to repro and fix.

llvm-svn: 364355
2019-06-25 22:22:13 +00:00
Tatyana Krasnukha d76c7b1c2a [unittests] Simplify CMakeLists with object library
The solution suggested by Chris Bieneman works for all versions of CMake.

Differential Revision: https://reviews.llvm.org/D63544

llvm-svn: 364035
2019-06-21 11:46:46 +00:00
Tatyana Krasnukha 36358cd3ed [unittests] Use object library if cmake supports it
Differential Revision: https://reviews.llvm.org/D63544

llvm-svn: 363933
2019-06-20 15:06:31 +00:00
Antonio Afonso a7335393f5 Add ReadCStringFromMemory for faster string reads
Summary:
This is the fifth patch to improve module loading in a series that started here (where I explain the motivation and solution): D62499

Reading strings with ReadMemory is really slow when reading the path of the shared library. This is because we don't know the length of the path so use PATH_MAX (4096) and these strings are actually super close to the boundary of an unreadable page. So even though we use process_vm_readv it will usually fail because the read size spans to the unreadable page and we then default to read the string word by word with ptrace.

This new function is very similar to another ReadCStringFromMemory that already exists in lldb that makes sure it never reads cross page boundaries and checks if we already read the entire string by finding '\0'.

I was able to reduce the GetLoadedSharedLibraries call from 30ms to 4ms (or something of that order).

Reviewers: clayborg, xiaobai, labath

Reviewed By: labath

Subscribers: emaste, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D62503

llvm-svn: 363750
2019-06-18 23:27:57 +00:00
Jonas Devlieghere c470ac50a8 [Reproducers] Make reproducer relocatable
Before this patch, reproducers weren't relocatable. The reproducer
contained hard coded paths in the VFS mapping, as well in the yaml file
listing the different input files for the command interpreter. This
patch changes that:

 - Use relative paths for the DataCollector.
 - Use an overlay prefix for the FileCollector.

Differential revision: https://reviews.llvm.org/D63467

llvm-svn: 363697
2019-06-18 16:20:17 +00:00
Antonio Afonso f4335b8e3c Implement GetSharedLibraryInfoAddress
Summary:
This is the third patch to improve module loading in a series that started here (where I explain the motivation and solution): D62499

Add functions to read the r_debug location to know where the linked list of loaded libraries are so I can generate the `xfer:libraries-svr4` packet.
I'm also using this function to implement `GetSharedLibraryInfoAddress` that was "not implemented" for linux.
Most of this code was inspired by the current ds2 implementation here: https://github.com/facebook/ds2/blob/master/Sources/Target/POSIX/ELFProcess.cpp.

Reviewers: clayborg, xiaobai, labath

Reviewed By: clayborg, labath

Subscribers: emaste, krytarowski, mgorny, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D62501

llvm-svn: 363458
2019-06-14 21:15:08 +00:00
Pavel Labath 2dd0053d3a EditlineTest: Improve error message
This test seems to occasionally fail because editline returns a
different number of lines. Rewrite the message in such a way that we
also see the actual lines when that happens (and not just their count).

Also, clean up the dependencies of the test while I'm in there.

llvm-svn: 363404
2019-06-14 14:33:04 +00:00
Pavel Labath d8aca8886f Make UniqueCStringMap work with non-default-constructible types and other improvements/cleanups
Summary:
The motivation for this was me wanting to make the validity of dwarf
DIERefs explicit (via llvm::Optional<DIERef>). This meant that the class
would no longer have a default constructor. As the DIERef was being
stored in a UniqueCStringMap, this meant that this container (like all
standard containers) needed to work with non-default-constructible types
too.

This part is achieved by removing the default constructors for the map
entry types, and providing appropriate comparison overloads so that we
can search for map entries without constructing a dummy entry. While
doing that, I took the opportunity to modernize the code, and add some
tests. Functions that were completely unused are deleted.

This required also some changes in the Symtab code, as it was default
constructing map entries, which was not impossible even though its
value type was default-constructible. Technically, these changes could
be avoided with some SFINAE on the entry type, but I felt that the code
is cleaner this way anyway.

Reviewers: JDevlieghere, sgraenitz

Subscribers: mgorny, aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D63268

llvm-svn: 363357
2019-06-14 06:33:31 +00:00
Jonas Devlieghere ef96e985fc [Reproducers] Simplify providers with nested Info struct (NFC)
This replaces the `info` typedef with a nested struct named Info. This
means we now have FooProvider and FooProvider::Info, instead of two
related but separate classes FooProvider and FooInfo. This change is
mostly cosmetic.

llvm-svn: 363211
2019-06-12 22:17:38 +00:00
Antonio Afonso 57e2da4f32 Create a generic handler for Xfer packets
Summary:
This is the first of a few patches I have to improve the performance of dynamic module loading on Android.

In this first diff I'll describe the context of my main motivation and will then link to it in the other diffs to avoid repeating myself.

## Motivation
I have a few scenarios where opening a specific feature on an Android app takes around 40s when lldb is attached to it. The reason for that is because 40 modules are dynamicly loaded at that point in time and each one of them is taking ~1s.

## The problem
To learn about new modules we have a breakpoint on a linker function that is called twice whenever a module is loaded. One time just before it's loaded (so lldb can check which modules are loaded) and another right after it's loaded (so lldb can check again which ones are loaded and calculate the diference).
It's figuring out which modules are loaded that is taking quite some time. This is currently done by traversing the linked list of loaded shared libraries that the linker maintains in memory. Each item in the linked list requires its own `x` packet sent to the gdb server (this is android so the network also plays a part). In my scenario there are 400+ loaded libraries and even though we read 0x800 worth of bytes at a time we still make ~180 requests that end up taking 150-200ms.
We also do this twice, once before the module is loaded (state = eAdd) and another right after (state = eConsistent) which easly adds up to ~400ms per module.

## A solution

**Implement `xfer:libraries-svr4` in lldb-server:**
I noticed in the code that loads the new modules that it had support for the `xfer:libraries-svr4` packet (added ~4 years ago to support the ds2 debug server) but we didn't support it in lldb-server. This single packet returns an xml list of all the loaded modules by the process. The advantage is that there's no more need to make 180 requests to read the linked list. Additionally this new requests takes around 10ms.

**More efficient usage of the `xfer:libraries-svr4` packet in lldb:**
When `xfer:libraries-svr4` is available the Process class has a `LoadModules` function that requests this packet and then loads or unloads modules based on the current list of loaded modules by the process.
This is the function that is used by the DYLDRendezvous class to get the list of loaded modules before and after the module is loaded. However, this is really not needed since the LoadModules function already loaded or unloaded the modules accordingly. I changed this strategy to call LoadModules only once (after the process has loaded the module).

**Bugs**
I found a few issues in lldb while implementing this and have submitted independent patches for them.

I tried to devide this into multiple logical patches to make it easier to review and discuss.

## Tests

I wanted to put these set of diffs up before having all the tests up and running to start having them reviewed from a techical point of view. I'm also having some trouble making the tests running on linux so I need more time to make that happen.

# This diff

The `xfer` packages follow the same protocol, they are requested with `xfer:<object>:<read|write>:<annex>:<offset,length>` and a return that starts with `l` or `m` depending if the offset and length covers the entire data or not. Before implementing the `xfer:libraries-svr4` I refactored the `xfer:auxv` to generically handle xfer packets so we can easly add new ones.

The overall structure of the function ends up being:
* Parse the packet into its components: object, offset etc.
* Depending on the object do its own logic to generate the data.
* Return the data based on its size, the requested offset and length.

Reviewers: clayborg, xiaobai, labath

Reviewed By: labath

Subscribers: mgorny, krytarowski, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D62499

llvm-svn: 362982
2019-06-10 20:59:58 +00:00