Also found/fixed one bug identified by this warning in
RenderScriptx86ABIFixups.cpp where a string literal was being used in an
effort to provide a name for an instruction/register, but was instead
being passed as the bool 'isVolatile' parameter.
llvm-svn: 291198
Added an extra field parser to the `RSModuleDescriptor` class enabling us to
check whether the versions of LLVM used to generated the debug symbols match
across the RenderScript compiler frontend (llvm-rs-cc) and backend (bcc); if
they do not, we warn the user that the debugging experience may be suboptimal
as LLVM IR debug information has no compatibility guarantees.
llvm-svn: 290957
This patch updates a bunch of places where add_dependencies was being explicitly called to add dependencies on intrinsics_gen to instead use the DEPENDS named parameter. This cleanup is needed for a patch I'm working on to add a dependency debugging mode to the build system.
llvm-svn: 287408
This is a large API change that removes the two functions from
StreamString that return a std::string& and a const std::string&,
and instead provide one function which returns a StringRef.
Direct access to the underlying buffer violates the concept of
a "stream" which is intended to provide forward only access,
and makes porting to llvm::raw_ostream more difficult in the
future.
Differential Revision: https://reviews.llvm.org/D26698
llvm-svn: 287152
When placing function name breakpoints on RenderScript Reduction kernel
functions, we were not skipping over the function prologue meaning that
inspection of the arguments could be garbled as the function was not finished
setting up the stack/registers.
In
[122fe8f](122fe8f472)
Aidan added the `SkipPrologue` function that allows us to trivially fix up the
kernel's functions' resolved addresses, falling gracefully back to the old
behaviour if we don't know how to handle the prologue or can't resolve its
size.
llvm-svn: 286387
This commit hooks the nofity function that signals script group
compilation. By tracking scriptgroups compiled at runtine, users
are able to place breakpoints by script group name. Breakpoints
will be placed on the kernels forming the group.
llvm-svn: 285902
- Add new `lldb_private::lldb_renderscript::RSReduceBreakpointResolver`
class that can set breakpoints on kernels that are constituent
functions of named reduction groups. Also support debugging of subsets
of the the reduction group with the `-t, --function-role` flag which
takes a comma-separated list of reduction function types
outconverter,combiner,initializer,accumulator (defaults to all)
- Add 2 new helper methods to `RenderScriptRuntime`,
1. `CreateReductionBreakpoint(name, types)`: instantiates a new
RSReduceBreakpointResolver and inserts that resolver into the running
process.
2. `PlaceBreakpointOnReduction`: which is a public helper function.
- hook up the above functionality to the command-line with new
`CommandObject*` classes that handle parsing of function roles and
dispatch to the runtime. These are namespaced under the snappy
`language renderscript reduction breakpoint ...` subcommand
- [incidental] Factor multiple common uses of
`FindFirstSymbolWithNameAndType(ConstString(".rs.info")` into static
`IsRenderScriptScriptModule(ModuleSP module)` function, and replace
original uses.
llvm-svn: 283362
Pay more attention to comment alignement (Since _The Great Reformat_ (a015ff50)
comments are no longer properly aligned) and variable naming conventions.
- Manually reflow and cleanup comments and array literals
- Be more economical with our naming conventions
- Be internally consistent with regard to local variable/member function
naming
llvm-svn: 283335
- This change updates the signature of
`RenderScriptRuntime::PlaceBreakpointOnKernel` to take a default
RSCoordinate pointer of nullptr. We use this as the predicate value for
the breakpoint coordinate rather than trying to fit a sentinel `-1` into
a signed version.
```
- void
- PlaceBreakpointOnKernel(Stream &strm, const char *name, const std::array<int, 3> coords, Error &error,
- lldb::TargetSP target);
```
```
+ bool
+ PlaceBreakpointOnKernel(lldb::TargetSP target, Stream &messages, const char *name,
+ const lldb_renderscript::RSCoordinate *coords = nullptr);
```
The above change makes the API for setting breakpoints on kernels
cleaner as it returns a failure value rather than modify a sentinel in
the caller. The optional arguments are now last and have a default
(falsey) value.
- RSCoordinate objects are now comparable with operator== and have
zero initializers which should make them easier to work on.
- Added a `FMT_COORD` macro for use in logging format strings which
should make format strings a little less verbose.
llvm-svn: 283320
These are missing dependencies that have been exposed in builds as a result of my change to make lldb libraries depend on CLANG_TABLEGEN_TARGETS instead of libclang.
llvm-svn: 283081
This change is very mechanical. All it does is change the
signature of `Options::GetDefinitions()` and `OptionGroup::
GetDefinitions()` to return an `ArrayRef<OptionDefinition>`
instead of a `const OptionDefinition *`. In the case of the
former, it deletes the sentinel entry from every table, and
in the case of the latter, it removes the `GetNumDefinitions()`
method from the interface. These are no longer necessary as
`ArrayRef` carries its own length.
In the former case, iteration was done by using a sentinel
entry, so there was no knowledge of length. Because of this
the individual option tables were allowed to be defined below
the corresponding class (after all, only a pointer was needed).
Now, however, the length must be known at compile time to
construct the `ArrayRef`, and as a result it is necessary to
move every option table before its corresponding class. This
results in this CL looking very big, but in terms of substance
there is not much here.
Differential revision: https://reviews.llvm.org/D24834
llvm-svn: 282188
This updates getters and setters to use StringRef instead of
const char *. I tested the build on Linux, Windows, and OSX
and saw no build or test failures. I cannot test any BSD
or Android variants, however I expect the required changes
to be minimal or non-existant.
llvm-svn: 282079
Initial implementation of support for tracking
[RenderScript Reductions](https://developer.android.com/guide/topics/renderscript/compute.html#reduction-in-depth)
With this patch, `language renderscript module dump` properly lists reductions
that are part of loaded RenderScript modules as well the the consituent
functions and their roles, within the reduction.
This support required new tracking mechanisms for the `#pragma(reduce)`
mechanism, and extension of `RSModuleDescriptor::ParseRSInfo` to support
the metadata output by `bcc`. This work was also an opportunity to
refactor/improve parse code:
- `RSModuleDescriptor::ParseExportReduceCount` now has a complete
implementation and the debugger can correctly track reductions on
receipt of a module hook.
- `RSModuleDescriptor::Dump` now dumps Reductions as well as `ForEach`
kernels. Also, fixed indentation of the output, and made indentation
groupings in the source clearer.
- `RSModuleDescriptor::ParseRSInfo` now returns true if the `".rs.info"`
packet has nonzero linecount, rather than rejecting RenderScripts that
don't contain kernels (an unlikely situation, but possibly valid). This
was changed because scripts that only contained reductions were not
being tracked in `RenderScriptRuntime::LoadModule`.
- Refactor `RSModuleInfo::ParseRSInfo` and add reduction spec parser stub
- Prepared ParseRSInfo to more easily be able to add new parser types
- Use llvm::StringRef and llvm::StringMap helpers to make the parsing code cleaner
- factor out forEachCount, globalVarCount, and pragmaCount parsing block to their own methods
- Add ExportReduceCount Parser
- Use `llvm::StringRef` in `RSKernelDescriptor` constructor
- removed now superfluous `MAXLINE` macros as we've switched from `const
char *` to `llvm::StringRef`
llvm-svn: 281717
Summary:
LLVM guys did some clean-up of the Attribute getters/setters
and because of that the build was failing.
Reviewers: ldrumm
Subscribers: lldb-commits
Differential Revision: https://reviews.llvm.org/D24382
llvm-svn: 281030
*** to conform to clang-format’s LLVM style. This kind of mass change has
*** two obvious implications:
Firstly, merging this particular commit into a downstream fork may be a huge
effort. Alternatively, it may be worth merging all changes up to this commit,
performing the same reformatting operation locally, and then discarding the
merge for this particular commit. The commands used to accomplish this
reformatting were as follows (with current working directory as the root of
the repository):
find . \( -iname "*.c" -or -iname "*.cpp" -or -iname "*.h" -or -iname "*.mm" \) -exec clang-format -i {} +
find . -iname "*.py" -exec autopep8 --in-place --aggressive --aggressive {} + ;
The version of clang-format used was 3.9.0, and autopep8 was 1.2.4.
Secondly, “blame” style tools will generally point to this commit instead of
a meaningful prior commit. There are alternatives available that will attempt
to look through this change and find the appropriate prior commit. YMMV.
llvm-svn: 280751
Options used to store a reference to the CommandInterpreter instance
in the base Options class. This made it impossible to parse options
independent of a CommandInterpreter.
This change removes the reference from the base class. Instead, it
modifies the options-parsing-related methods to take an
ExecutionContext pointer, which the options may inspect if they need
to do so.
Closes https://reviews.llvm.org/D23416
Reviewers: clayborg, jingham
llvm-svn: 278440
Due to internal reuse of buffers in the RenderScript runtime by the system allocator,
comparing pointers is not a safe way to check whether an allocation is tracked by lldb.
This change updates the lldb RenderScript internal hook callback to properly
identify and remove old allocations that had have an address that is currently
being tracked.
This change also removes the need for `lldb_private::renderscript::LookupAllocation`
to take a `create` flag, as this is now always the case.
Original Author: <dean@codeplay.com>
Subscribers: lldb-commits
llvm-svn: 277613
``num_params`` was unused in RenderScript ABI fixup pass ``cloneToStructRetFnTy``
and was only used in an `assert()` that the number of function parameters for the cloned
function was correct.
Now we actually use this variable, rather than recomputing it, and avoid the unused variable
warning when building without asserts enabled.
Subscribers: lldb-commits
llvm-svn: 277608
Expression evaluation for function calls to certain public RenderScript
API functions in libRSCPURef can segfault.
`slang`,
the compiler frontend for RenderScript embeds an ARM specific triple in
IR that is shipped in the app, after generating IR that has some
assumptions that an ARM device is the target.
As the IR is then compiled on a device of unknown (at time the IR was
generated at least) architecture, when calling RenderScript API function
as part of debugger expressions, we have to perform a fixup pass that
removes those assumptions right before the module is sent to be
generated by the llvm backend.
This issue is caused by multiple problems with the ARMv7-specific
assumptions encoded in the LLVM IR. x86 large value returns use a hidden
first argument (mapping to llvm::Attribute::StructRet), which can't be
picked up by the JIT due to the mismatch between IR generated by the
slang frontend and llvm backend. This means that code generated by bcc
did not necessarily match the default SysV Linux/Android ABI used by the
LLDB JIT
- Original Authors: Luke Drummond (@ldrumm), Function declarations fixed by Aidan Dodds (@ADodds)
Subscribers: lldb-commits
Differential Revision: https://reviews.llvm.org/D18059
llvm-svn: 276976
review it for consistency, accuracy, and clarity. These changes attempt to
address all of the above while keeping the text relatively terse.
<rdar://problem/24868841>
llvm-svn: 275485
"Allow LanguageRuntimes to return an error if they fail in the course of dynamic type discovery
This is not meant to report that a value doesn't have a dynamic type - it is only meant as a mechanism to propagate actual type discovery issues (e.g. malformed type metadata for languages that have such a notion)
This information is used by ValueObjectDynamic to set its own m_error, which is a fairly sharp and heavyweight tool to begin with
For the time being, this is an architectural improvement but a practical no-op as no existing runtimes are actually setting errors"
I need to think about what I want to do in this space more carefully - this attempt might be too heavy of a hammer for the nail I am trying to fix, and I don't want to leave it in while I ponder
llvm-svn: 268686
This is not meant to report that a value doesn't have a dynamic type - it is only meant as a mechanism to propagate actual type discovery issues (e.g. malformed type metadata for languages that have such a notion)
This information is used by ValueObjectDynamic to set its own m_error, which is a fairly sharp and heavyweight tool to begin with
For the time being, this is an architectural improvement but a practical no-op as no existing runtimes are actually setting errors
llvm-svn: 268591
Fix a problem raised with the previous patches being applied in the wrong order.
Committed on behalf of: Dean De Leo <dean@codeplay.com>
llvm-svn: 263134
This commit implements the reading of stack spilled function arguments for little endian MIPS targets.
Committed on behalf of: Dean De Leo <dean@codeplay.com>
llvm-svn: 263131
This commit implements the reading of stack spilled function arguments for little endian MIPS targets.
Committed on behalf of: Dean De Leo <dean@codeplay.com>
llvm-svn: 263130
Currently it is not specified, and since allocations are usually
requested once we hit a renderscript breakpoint, the language will be
inferred being as renderscript by the ExpressionParser.
Actually allocations attempt to invoke functions part of the RS runtime,
written in C/C++, so evaluating the calls in RenderScript could be
misleading.
In particular, in MIPS, the ABI between C/C++ (mips o32) and
renderscript (arm) might introduce subtle bugs when evaluating such
expressions.
This change explicitly sets the language used to evaluate the allocations
as C++.
Committed on behalf of: Dean De Leo <dean@codeplay.com>
llvm-svn: 263129
Mips64 tests were failing on windows because the sscanf implementation differs between clang/gcc/msvc such that on windows %lx specifies a 32bits parameter and %llx is for 64bits. For us this meant that 64bit pointers were being truncated to 32bits on their way into a JIT'd expression.
llvm-svn: 261741
This patch reworks the function argument reading code, allowing us to annotate arguments with their types. The type/size information is needed to correctly parse arguments passed on the stack.
llvm-svn: 260525
Obviously, if the original Debugger goes away, those commands are holding on to now stale memory, which has the potential to cause crashes
Fixes rdar://24460882
llvm-svn: 259964
Patch replaces the --refresh flag removed in r258800 with it's own command, 'language renderscript allocation refresh'.
Since there is no reason this functionality should be tied to another command as an option.
The command itself simply re-JITs all our cached information about allocations.
llvm-svn: 259773
Patch deletes the 'language renderscript module probe' command.
This command was present in the initial commit to help debug the plugin.
However we haven't used it recently and it's functionality is unclear, so can be removed entirely.
Also add back 'kernel coordinate' command, removed by accident in clang format patch r259056.
llvm-svn: 259181
Patch replaces the 'renderscript allocation list' command flag --refresh, with a new option --id <ID>.
This new option only prints the details of a single allocation with a given id, rather than printing all the allocations.
Functionality from the removed '--refresh' flag will be moved into its own command in a subsequent commit.
llvm-svn: 258800
std::array should have "the same semantics as a struct holding a C-style array T[N] as its only
non-static data member", so the initialization should have one more level of braces. Hopefully,
no compiler will object to that.
llvm-svn: 258306
Patch adds command 'language renderscript kernel coordinate' for printing the kernel index in (x,y,z) format.
This is done by walking the call stack and looking for a function with suffix '.expand', as well as the frame variables containing the coordinate data.
llvm-svn: 258303
Reverts earlier commit r254910, which used function pointers for jitted expressions
to avoid a Mips64 compiler bug. Bug has since been fixed, and compiler longer issues the problem instruction.
Author: Dean De Leo <dean@codeplay.com>
llvm-svn: 258038
Summary:
This change is relevant for inferiors compiled with GCC. GCC does not
emit complete debug info for std::basic_string<...>, and consequently, Clang
(the LLDB compiler) does not generate correct mangled names for certain
functions.
This change removes the hard-coded alternate names in
ItaniumABILanguageRuntime.cpp.
Before the hard-coded names were put in ItaniumABILanguageRuntime.cpp, one could
not evaluate std::string methods (ex. std::string::length). After putting in
the hard-coded names, one could evaluate them. However, it did not still
enable one to call methods on, say for example, std::vector<string>.
This change makes that possible.
There is some amount of incompleteness in this change. Consider the
following example:
std::string hello("hello"), world("world");
std::map<std::string, std::string> m;
m[hello] = world;
One can still not evaluate the expression "m[hello]" in LLDB. Will
address this issue in another pass.
Reviewers: jingham, vharron, evgeny777, spyffe, dawn
Subscribers: clayborg, dawn, lldb-commits
Differential Revision: http://reviews.llvm.org/D12809
llvm-svn: 257113
Updates the file format for storing RS allocations to a file, so that the format now supports struct element types.
The file header will now contain a subheader for every RS element and it's descendants.
Where an element subheader contains element type details and offsets to the subheaders of that elements fields.
Patch also improves robustness when loading incorrect files.
llvm-svn: 257045
Function arguments that were spilled and passed on the stack were incorrectly read.
The value was written back into the output pointer rather then the memory being pointed to.
llvm-svn: 256941
Reverts "Use correct format identifiers to print something meaningful."
Original format specifiers were correct.
Instead use void* casts to remove warnings, since this is what the %p specifier expects.
llvm-svn: 256833
Currently we can just inspect the details of the most common allocation types.
This patch allows us to support all the types defined by the RS runtime in its `RsDataType` enum.
Including handlers, matrices and packed graphical data.
llvm-svn: 255904
Adds support for reading a maximum of six integer arguments from a renderscript hook on X86_64.
Author: Luke Drummond <luke.drummond@codeplay.com>
llvm-svn: 255338
Patch creates a member function that decides when to JIT all the details about an allocation.
By checking for zero pointers we can avoid the situation where we store uninitialised data from previously inspecting the allocation during creation.
llvm-svn: 255238
New hook for rsdAllocationDestroy() which is called when allocations are deleted.
LLDB should be aware of this so we can remove the allocation from our internal list.
llvm-svn: 255121
Workaround for Mips64 compiler bug by using function pointers to call
functions for expression evaluation. This avoids the emission of the JAL instruction,
which can only jump within a particular range of the PC.
Author: Dean De Leo, dean@codeplay.com
llvm-svn: 254910
This patch adds functionality for dumping allocations of struct elements. This involves:
+ Jitting the runtime for details on all the struct fields.
+ Finding the name of the struct type by looking for a global variable of the same type, which will have been reflected back to the java host code.
+ Using this struct type name to pass into expression evaluation for pretty printing the data for the dump command.
llvm-svn: 254294
Adds option -c <x,y,z> to the 'language renderscript kernel breakpoint set' command.
Breaks only on the invocation of the kernel with specified coordinate.
Implemented by adding a callback to the kernel breakpoint which checks the coordinates of every invocation.
llvm-svn: 251293
Previously we could not hook the RS runtime on mips64 architectures.
Patch implements ABI specific code for inspecting function arguments.
Author: Dean De Leo, dean@codeplay.com
llvm-svn: 251003
Patch adds command 'language renderscript allocation save' to store the contents of an allocation in a binary file.
And 'language renderscript allocation load' to restore an allocation with the saved data from a binary file.
Binary file format contains a header FileHeader with meta information preceding the raw data.
Reviewed by: jingham, clayborg
Subscribers: lldb-commits, domipheus
Differential Revision: http://reviews.llvm.org/D13903
llvm-svn: 250886
Previous commit r250281 broke TestDataFormatterSmartArray.py
Resolved in in this patch by adding the new enum eFormatVectorOfFloat16 to FormatManager.
Differential Revision: http://reviews.llvm.org/D13730
llvm-svn: 250499
This patch adds the command 'language renderscript allocation dump <ID>' for printing the contents of a RS allocation.
Displaying the coordinate of each element as well as its formatted value
e.g (lldb) language renderscript allocation dump 1
Data (X, Y, Z):
(0, 0, 0) = {0 1}
(1, 0, 0) = {2 3}
(2, 0, 0) = {4 5}
A --file <filename> option is also included, since for large allocations it may be more helpful to view this text as a file.
Reviewed by: jingham, clayborg
Subscribers: lldb-commits, ADodds, domipheus, brucem
Differential Revision: http://reviews.llvm.org/D13699
llvm-svn: 250281
This patch adds a new command 'language renderscript allocation list' for printing the details of all loaded RS allocations.
In order to work out this information lldb JITs the runtime for the data it wants.
This has a penalty of a couple seconds latency, so is only done once for each allocation and the results cached.
If the user later wants to recalculate this information however, they can force lldb to do so with the --refresh flag.
Reviewed by: jingham, clayborg
Subscribers: lldb-commits, ADodds, domipheus, dean, tberghammer, danalbert, srhines
Differential Revision: http://reviews.llvm.org/D13247
llvm-svn: 249380
This is meant to cover cases such as the obvious
Base *base = new Derived();
where GetDynamicTypeAndAddress(base) would return the type "Derived", not "Derived *"
llvm-svn: 248315
After the std::move operation the unique pointer is null.
So this statement always returns a null pointer.
Also remove unnecessary call to Module::ParseAllDebugSymbols(),
which spews errors due to how it incorrectly tries to parse DWARF DIE types.
llvm-svn: 248274
This patch adds some of the groundwork required for tracking the lifetime of scripts and allocations and collecting data associated with them during execution.
Committed on behalf of Aidan Dodds.
Authored by: ADodds
Reviewed by: clayborg, jingham
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D12936
llvm-svn: 248149
For C++ and ObjC, dynamic values are always (at least somewhat) pointer-like in nature, so a ValueType of scalar is actually good enough that it could originally be hardcoded as the right choice
Other languages, might have broader notions of things that are dynamic (e.g. a language where a value type can be dynamic). In those cases, it might actually be the case that a dynamic value is a pointer-to the data, or even a host address if dynamic expression results entirely in host space are being talked about
This patch enables the language runtime to make that decision, and makes ValueObjectDynamicValue comply with it
llvm-svn: 247957
Use Breakpoint::AddName to mark all RenderScript kernel breakpoints with the name 'RenderScriptKernel'.
Also update logging channels to include LIBLLDB_LOG_BREAKPOINT where appropriate.
llvm-svn: 247782
Patch adds a command to RenderScript plugin allowing users to automatically set breakpoints on every RS kernel.
Command syntax is 'language renderscript kernel breakpoint all <enable/disable>.'
Enable sets breakpoints on all currently loaded kernels, and any kernels which will be loaded in future.
Disable results in breakpoints no longer being set on loaded kernels, but doesn't affect existing breakpoints.
Current command 'language renderscript kernel breakpoint' is changed to 'language renderscript kernel breakpoint set'
Reviewed by: clayborg, jingham
Subscribers: lldb-commits, ADodds, domipheus
Differential Revision: http://reviews.llvm.org/D12728
llvm-svn: 247262
Currently the RS breakpoint command can only find a kernel if it's in an already loaded RS module.
This patch allows users to set pending breakpoints on RenderScript kernels which will be loaded in the future.
Implemented by creating a RS breakpoint resolver, to limit search scope to only RS modules.
Reviewed by: clayborg, jingham
Subscribers: lldb-commits, ADodds, domipheus
Differential Revision: http://reviews.llvm.org/D12360
llvm-svn: 246842
Summary:
This doesn't exist in other LLVM projects any longer and doesn't
do anything.
Reviewers: chaoren, labath
Subscribers: emaste, tberghammer, lldb-commits, danalbert
Differential Revision: http://reviews.llvm.org/D12586
llvm-svn: 246749
Summary:
When calling find_first_of and find_last_of on a single character,
we can instead just call find / rfind and make our intent more
clear.
Reviewers: clayborg
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D12518
llvm-svn: 246609
The kernels_found variable is not initialized, so if it is not assigned true on line 823, then it will be a garbage value in the branch condition on line 828. This patch initializes the variable to false.
Patch by neilparikh.
Reviewers: domipheus
Differential Revision: http://reviews.llvm.org/D11323
llvm-svn: 243104
Summary: This aligns the library names used by the Makefile build to be the same as those create by the CMake build to make switching between the two easier. The only major difficulty was lldbHost which was one library in the CMake system and several in the Makefile system. Most of the other changes are trivial renames.
Reviewers: labath
Subscribers: emaste, tberghammer, lldb-commits
Differential Revision: http://reviews.llvm.org/D11154
llvm-svn: 242196
A few extras were fixed
- Symbol::GetAddress() now returns an Address object, not a reference. There were places where people were accessing the address of a symbol when the symbol's value wasn't an address symbol. On MacOSX, undefined symbols have a value zero and some places where using the symbol's address and getting an absolute address of zero (since an Address object with no section and an m_offset whose value isn't LLDB_INVALID_ADDRESS is considered an absolute address). So fixing this required some changes to make sure people were getting what they expected.
- Since some places want to access the address as a reference, I added a few new functions to symbol:
Address &Symbol::GetAddressRef();
const Address &Symbol::GetAddressRef() const;
Linux test suite passes just fine now.
<rdar://problem/21494354>
llvm-svn: 240702
Base framework for inspecting RenderScript runtime details and helpers for various runtime actions on x86 and arm targets.
Differential Revision: http://reviews.llvm.org/D10151
llvm-svn: 238768
This works for Python commands defined via a class (implement get_flags on your class) and C++ plugin commands (which can call SBCommand::GetFlags()/SetFlags())
Flags allow features such as not letting the command run if there's no target, or if the process is not stopped, ...
Commands could always check for these things themselves, but having these accessible via flags makes custom commands more consistent with built-in ones
llvm-svn: 238286
Plan is to have this initialized on a per-process basis somewhat the same as the ObjC library on module loading, but this commit is simply the foundation work and will be incrementally built upon to add that detection functionality.
Differential Revision: http://reviews.llvm.org/D8896
llvm-svn: 234503
Chris Bieneman