Commit Graph

133 Commits

Author SHA1 Message Date
Lang Hames 0aec49c853 [ORC] Add support for resource tracking/removal (removable code).
This patch introduces new APIs to support resource tracking and removal in Orc.
It is intended as a thread-safe generalization of the removeModule concept from
OrcV1.

Clients can now create ResourceTracker objects (using
JITDylib::createResourceTracker) to track resources for each MaterializationUnit
(code, data, aliases, absolute symbols, etc.) added to the JIT. Every
MaterializationUnit will be associated with a ResourceTracker, and
ResourceTrackers can be re-used for multiple MaterializationUnits. Each JITDylib
has a default ResourceTracker that will be used for MaterializationUnits added
to that JITDylib if no ResourceTracker is explicitly specified.

Two operations can be performed on ResourceTrackers: transferTo and remove. The
transferTo operation transfers tracking of the resources to a different
ResourceTracker object, allowing ResourceTrackers to be merged to reduce
administrative overhead (the source tracker is invalidated in the process). The
remove operation removes all resources associated with a ResourceTracker,
including any symbols defined by MaterializationUnits associated with the
tracker, and also invalidates the tracker. These operations are thread safe, and
should work regardless of the the state of the MaterializationUnits. In the case
of resource transfer any existing resources associated with the source tracker
will be transferred to the destination tracker, and all future resources for
those units will be automatically associated with the destination tracker. In
the case of resource removal all already-allocated resources will be
deallocated, any if any program representations associated with the tracker have
not been compiled yet they will be destroyed. If any program representations are
currently being compiled then they will be prevented from completing: their
MaterializationResponsibility will return errors on any attempt to update the
JIT state.

Clients (usually Layer writers) wishing to track resources can implement the
ResourceManager API to receive notifications when ResourceTrackers are
transferred or removed. The MaterializationResponsibility::withResourceKeyDo
method can be used to create associations between the key for a ResourceTracker
and an allocated resource in a thread-safe way.

RTDyldObjectLinkingLayer and ObjectLinkingLayer are updated to use the
ResourceManager API to enable tracking and removal of memory allocated by the
JIT linker.

The new JITDylib::clear method can be used to trigger removal of every
ResourceTracker associated with the JITDylib (note that this will only
remove resources for the JITDylib, it does not run static destructors).

This patch includes unit tests showing basic usage. A follow-up patch will
update the Kaleidoscope and BuildingAJIT tutorial series to OrcV2 and will
use this API to release code associated with anonymous expressions.
2020-10-18 21:02:54 -07:00
Simon Pilgrim 9202902ae6 RuntimeDyldImpl.h - remove unused Twine forward declaration. NFC. 2020-04-22 15:07:17 +01:00
Benjamin Kramer e64e516790 [RuntimeDyld] Replace hand-rolled endian conversion with support::endian. NFCI. 2020-04-06 13:22:53 +02:00
Lang Hames 39253a50f0 [ORC] Re-apply 98f2bb4461, enable JITEventListeners in OrcV2, with fixes.
Updates the object buffer ownership scheme in jitLinkForOrc and related
functions: Ownership of both the object::ObjectFile and underlying
MemoryBuffer is passed into jitLinkForOrc and passed back to the onEmit
callback once linking is complete. This avoids the use-after-free errors
that were seen in 98f2bb4461.
2020-03-19 16:30:08 -07:00
Lang Hames 337e131ca7 [RuntimeDyld][COFF] Build stubs for COFF dllimport symbols.
Summary:
Enables JIT-linking by RuntimeDyld of COFF objects that contain references to
dllimport symbols. This is done by recognizing symbols that start with the
reserved "__imp_" prefix and building a pointer entry to the target symbol in
the stubs area of the section. References to the "__imp_" symbol are updated to
point to this pointer.

Work in progress: The generic code is in place, but only RuntimeDyldCOFFX86_64
and RuntimeDyldCOFFI386 have been updated to look for and update references to
dllimport symbols.

Reviewers: compnerd

Subscribers: hiraditya, ributzka, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75884
2020-03-10 16:08:40 -07:00
serge-sans-paille cb06571a44 Avoid dangling reference on SectionList
Bug spotted by https://cookieplmonster.github.io/2020/02/01/emulator-bug-llvm-bug/

Basically, holding references to object inside a resized vector is a bad idea.

Differential Revision: https://reviews.llvm.org/D75110
2020-03-05 09:42:24 +01:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Benjamin Kramer ce74c3b19f [Orc] Address the remaining move-capture FIXMEs
This required spreading unique_function a bit more, which I think is a
good thing.

llvm-svn: 371843
2019-09-13 11:35:33 +00:00
Lang Hames c7c1f21525 Simplify decoupling between RuntimeDyld/RuntimeDyldChecker, add 'got_addr' util.
This patch reduces the number of functions in the interface between RuntimeDyld
and RuntimeDyldChecker by combining "GetXAddress" and "GetXContent" functions
into "GetXInfo" functions that return a struct describing both the address and
content. The GetStubOffset function is also replaced with a pair of utilities,
GetStubInfo and GetGOTInfo, that fit the new scheme. For RuntimeDyld both of
these functions will return the same result, but for the new JITLink linker
(https://reviews.llvm.org/D58704) these will provide the addresses of PLT stubs
and GOT entries respectively.

For JITLink's use, a 'got_addr' utility has been added to the rtdyld-check
language, and the syntax of 'got_addr' and 'stub_addr' has been changed: both
functions now take two arguments, a 'stub container name' and a target symbol
name. For llvm-rtdyld/RuntimeDyld the stub container name is the object file
name and section name, separated by a slash. E.g.:

rtdyld-check: *{8}(stub_addr(foo.o/__text, y)) = y

For the upcoming llvm-jitlink utility, which creates stubs on a per-file basis
rather than a per-section basis, the container name is just the file name. E.g.:

jitlink-check: *{8}(got_addr(foo.o, y)) = y
llvm-svn: 358295
2019-04-12 18:07:28 +00:00
Lang Hames 941f247d30 [RuntimeDyld] Decouple RuntimeDyldChecker from RuntimeDyld.
This will allow RuntimeDyldChecker (and rtdyld-check tests) to test a new JIT
linker: JITLink (https://reviews.llvm.org/D58704).

llvm-svn: 357947
2019-04-08 21:50:48 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Lang Hames abeedf1812 [ORC] Add an asynchronous jit-link function, jitLinkForORC, to RuntimeDyld and
switch RTDyldObjectLinkingLayer2 to use it.

RuntimeDyld::loadObject is currently a blocking operation. This means that any
JIT'd code whose call-graph contains an embedded complete K graph will require
at least K threads to link, which precludes the use of a fixed sized thread
pool for concurrent JITing of arbitrary code (whatever K the thread-pool is set
at, any code with a K+1 complete subgraph will deadlock at JIT-link time).

To address this issue, this commmit introduces a function called jitLinkForORC
that uses continuation-passing style to pass the fix-up and finalization steps
to the asynchronous symbol resolver interface so that linking can be performed
without blocking.

llvm-svn: 343043
2018-09-25 22:57:44 +00:00
Lang Hames adde5ba4b2 [ORC] Reapply r342939 with a fix for MSVC's promise/future restrictions.
llvm-svn: 343012
2018-09-25 19:48:46 +00:00
Lang Hames 99bfa95ae3 Revert "[ORC] Switch to asynchronous resolution in JITSymbolResolver."
This reverts commit r342939.

MSVC's promise/future implementation does not like types that are not default
constructible. Reverting while I figure out a solution.

llvm-svn: 342941
2018-09-25 04:54:03 +00:00
Lang Hames 0e5b60326e [ORC] Switch to asynchronous resolution in JITSymbolResolver.
Asynchronous resolution (where the caller receives a callback once the requested
set of symbols are resolved) is a core part of the new concurrent ORC APIs. This
change extends the asynchronous resolution model down to RuntimeDyld, which is
necessary to prevent deadlocks when compiling/linking on a fixed number of
threads: If RuntimeDyld's linking process were a blocking operation, then any
complete K-graph in a program will require at least K threads to link in the
worst case, as each thread would block waiting for all the others to complete.
Using callbacks instead allows the work to be passed between dependent threads
until it is complete.

For backwards compatibility, all existing RuntimeDyld functions will continue
to operate in blocking mode as before. This change will enable the introduction
of a new async finalization process in a subsequent patch to enable asynchronous
JIT linking.

llvm-svn: 342939
2018-09-25 04:43:38 +00:00
Lang Hames bfea8cdc69 [ORC] Add a 'Callable' flag to JITSymbolFlags.
The callable flag can be used to indicate that a symbol is callable. If present,
the symbol is callable. If absent, the symbol may or may not be callable (the
client must determine this by context, for example by examining the program
representation that will provide the symbol definition).

This flag will be used in the near future to enable creation of lazy compilation
stubs based on SymbolFlagsMap instances only (without having to provide
additional information to determine which symbols need stubs).

llvm-svn: 338649
2018-08-01 22:42:23 +00:00
Adrian Prantl 4dfcc4a788 Remove @brief commands from doxygen comments, too.
This is a follow-up to r331272.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by
  for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done

https://reviews.llvm.org/D46290

llvm-svn: 331275
2018-05-01 16:10:38 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Lang Hames 313f590aee [ExecutionEngine] Add a getSymbolTable method to RuntimeDyld.
This can be used to extract the symbol table from a RuntimeDyld instance prior
to disposing of it.

This patch also updates RTDyldObjectLinkingLayer to use the new method, rather
than requesting symbols one at a time via getSymbol.

llvm-svn: 327476
2018-03-14 06:25:07 +00:00
Lang Hames b72f48452c [ORC] Re-apply r322913 with a fix for a read-after-free error.
ExternalSymbolMap now stores the string key (rather than using a StringRef),
as the object file backing the key may be removed at any time.

llvm-svn: 323001
2018-01-19 22:24:13 +00:00
Lang Hames 44efd042a2 [ORC] Revert r322913 while I investigate an ASan failure.
llvm-svn: 322914
2018-01-19 01:40:26 +00:00
Lang Hames 817df9fa0c [ORC] Redesign the JITSymbolResolver interface to support bulk queries.
Bulk queries reduce IPC/RPC overhead for cross-process JITing and expose
opportunities for parallel compilation.

The two new query methods are lookupFlags, which finds the flags for each of a
set of symbols; and lookup, which finds the address and flags for each of a
set of symbols. (See doxygen comments for more details.)

The existing JITSymbolResolver class is renamed LegacyJITSymbolResolver, and
modified to extend the new JITSymbolResolver class using the following scheme:

- lookupFlags is implemented by calling findSymbolInLogicalDylib for each of the
symbols, then returning the result of calling getFlags() on each of these
symbols. (Importantly: lookupFlags does NOT call getAddress on the returned
symbols, so lookupFlags will never trigger materialization, and lookupFlags will
never call findSymbol, so only symbols that are part of the logical dylib will
return results.)

- lookup is implemented by calling findSymbolInLogicalDylib for each symbol and
falling back to findSymbol if findSymbolInLogicalDylib returns a null result.
Assuming a symbol is found its getAddress method is called to materialize it and
the result (if getAddress succeeds) is stored in the result map, or the error
(if getAddress fails) is returned immediately from lookup. If any symbol is not
found then lookup returns immediately with an error.

This change will break any out-of-tree derivatives of JITSymbolResolver. This
can be fixed by updating those classes to derive from LegacyJITSymbolResolver
instead.

llvm-svn: 322913
2018-01-19 01:12:40 +00:00
Lang Hames 14a22a442d [RuntimeDyld][ORC] Add support for Thumb mode to RuntimeDyldMachOARM.
This patch adds support for thumb relocations to RuntimeDyldMachOARM, and adds
a target-specific flags field to JITSymbolFlags (so that on ARM we can record
whether each symbol is Thumb-mode code).

RuntimeDyldImpl::emitSection is modified to ensure that stubs memory is
correctly aligned based on the size returned by getStubAlignment().

llvm-svn: 310517
2017-08-09 20:19:27 +00:00
Lang Hames 4ce98662e7 [ORC] Errorize the ORC APIs.
This patch updates the ORC layers and utilities to return and propagate
llvm::Errors where appropriate. This is necessary to allow ORC to safely handle
error cases in cross-process and remote JITing.

llvm-svn: 307350
2017-07-07 02:59:13 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Lang Hames c936ac7f37 [ExecutionEngine] Make RuntimeDyld::MemoryManager responsible for tracking EH
frames.

RuntimeDyld was previously responsible for tracking allocated EH frames, but it
makes more sense to have the RuntimeDyld::MemoryManager track them (since the
frames are allocated through the memory manager, and written to memory owned by
the memory manager). This patch moves the frame tracking into
RTDyldMemoryManager, and changes the deregisterFrames method on
RuntimeDyld::MemoryManager from:

void deregisterEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size);

to:

void deregisterEHFrames();

Separating this responsibility will allow ORC to continue to throw the
RuntimeDyld instances away post-link (saving a few dozen bytes per lazy
function) while properly deregistering frames when modules are unloaded.

This patch also updates ORC to call deregisterEHFrames when modules are
unloaded. This fixes a bug where an exception that tears down the JIT can then
unwind through dangling EH frames that have been deallocated but not
deregistered, resulting in UB.

For people using SectionMemoryManager this should be pretty much a no-op. For
people with custom allocators that override registerEHFrames/deregisterEHFrames,
you will now be responsible for tracking allocated EH frames.

Reviewed in https://reviews.llvm.org/D32829

llvm-svn: 302589
2017-05-09 21:32:18 +00:00
Eugene Leviant 3e582c8855 RuntimeDyldELF/AArch64: Implement basic GOT support
This patch implements two GOT relocations:
R_AARCH64_ADR_GOT_PAGE and R_AARCH64_LD64_GOT_LO12_NC

Differential revision: https://reviews.llvm.org/D28571

llvm-svn: 294191
2017-02-06 15:31:28 +00:00
Simon Dardis 226752c15d [mips][mcjit] Add the majority of N32 support.
The missing piece is relocation composition for %hi(%neg(%gp_rel(x))) and
similar.

Patch by: Daniel Sanders

llvm-svn: 284724
2016-10-20 13:02:23 +00:00
Walter Erquinigo b58d6a5655 Handle relocations to thumb functions when dynamic linking COFF modules
Summary:
This adds the necessary logic to support relocations to thumb functions in the COFF dynamic linker.
The jumps to function addresses are mostly blx, which requires the ISA selection bit when jumping to a thumb function.

Note: I'm determining if the relocation requires the ISA bit when creating the relocation entries and not when resolving the relocation. I have to do that because I need the ObjectFile and the actual Symbol, which are available only when creating the entries. It would require a gross refactor if I do it otherwise, but I'm okay with doing it if you think it's better.

Reviewers: peter.smith, compnerd

Subscribers: rengolin, sas

Differential Revision: https://reviews.llvm.org/D25151

llvm-svn: 284410
2016-10-17 18:56:18 +00:00
Lang Hames aac59a26a5 [ExecutionEngine] Refactor - Roll JITSymbolFlags functionality into JITSymbol.h
and remove the JITSymbolFlags header.

llvm-svn: 277766
2016-08-04 20:32:37 +00:00
Lang Hames ad4a911fea [ExecutionEngine][MCJIT][Orc] Replace RuntimeDyld::SymbolInfo with JITSymbol.
This patch replaces RuntimeDyld::SymbolInfo with JITSymbol: A symbol class
that is capable of lazy materialization (i.e. the symbol definition needn't be
emitted until the address is requested). This can be used to support common
and weak symbols in the JIT (though this is not implemented in this patch).

For consistency, RuntimeDyld::SymbolResolver is renamed to JITSymbolResolver.

For space efficiency a new class, JITEvaluatedSymbol, is introduced that
behaves like the old RuntimeDyld::SymbolInfo - i.e. it is just a pair of an
address and symbol flags. Instances of JITEvaluatedSymbol can be used in
symbol-tables to avoid paying the space cost of the materializer.

llvm-svn: 277386
2016-08-01 20:49:11 +00:00
Lang Hames 8959531c51 [RuntimeDyld] Plumb Error/Expected through the internals of RuntimeDyld.
Also replaces a number of calls to report_fatal_error with Error returns.

The plumbing will make it easier to return errors originating in libObject.

Replacing report_fatal_errors with Error returns will give JIT clients the
opportunity to recover gracefully when the JIT is unable to produce/relocate
code, as well as providing meaningful error messages that can be used to file
bug reports.

llvm-svn: 267776
2016-04-27 20:24:48 +00:00
Kevin Enderby 81e8b7d949 Thread Expected<...> up from libObject’s getName() for symbols to allow llvm-objdump to produce a good error message.
Produce another specific error message for a malformed Mach-O file when a symbol’s
string index is past the end of the string table.  The existing test case in test/Object/macho-invalid.test
for macho-invalid-symbol-name-past-eof now reports the error with the message indicating
that a symbol at a specific index has a bad sting index and that bad string index value.
 
Again converting interfaces to Expected<> from ErrorOr<> does involve
touching a number of places. Where the existing code reported the error with a
string message or an error code it was converted to do the same.  There is some
code for this that could be factored into a routine but I would like to leave that for
the code owners post-commit to do as they want for handling an llvm::Error.  An
example of how this could be done is shown in the diff in
lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h which had a Check() routine
already for std::error_code so I added one like it for llvm::Error .

Also there some were bugs in the existing code that did not deal with the
old ErrorOr<> return values.  So now with Expected<> since they must be
checked and the error handled, I added a TODO and a comment:
“// TODO: Actually report errors helpfully” and a call something like
consumeError(NameOrErr.takeError()) so the buggy code will not crash
since needed to deal with the Error.

Note there fixes needed to lld that goes along with this that I will commit right after this.
So expect lld not to built after this commit and before the next one.

llvm-svn: 266919
2016-04-20 21:24:34 +00:00
Mehdi Amini b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Lang Hames b2b7a3c179 [RuntimeDyld] Add alignment arguments to the reserveAllocationSpace method of
RuntimeDyld::MemoryManager.

The RuntimeDyld::MemoryManager::reserveAllocationSpace method is called when
object files are loaded, and gives clients a chance to pre-allocate memory for
all segments. Previously only the size of each segment (code, ro-data, rw-data)
was supplied but not the alignment. This hasn't caused any problems so far, as
most clients allocate via the MemoryBlock interface which returns page-aligned
blocks. Adding alignment arguments enables finer grained allocation while still
satisfying alignment restrictions.

llvm-svn: 257294
2016-01-10 18:51:50 +00:00
Keno Fischer eb59d468d9 [RuntimeDyld] DenseMap -> std::unordered_map
DenseMap is most applicable when both keys and values are small.
In this case, the value violates that assumption, causing quite
significant memory overhead. A std::unordered_map is more appropriate
in this case (or at least fixed the memory problems I was seeing).

Differential Revision: http://reviews.llvm.org/D14910

llvm-svn: 254651
2015-12-03 21:27:59 +00:00
Sanjoy Das 5abfbb9246 [RuntimeDyld] Avoid unused-private-field warning; NFC
Fixes the no asserts -Werror,-Wunused-private-field build.

llvm-svn: 253933
2015-11-23 22:59:36 +00:00
Sanjoy Das d5658b0896 [RuntimeDyld] Don't allocate unnecessary stub buffer space
Summary:
For relocation types that are known to not require stub functions, there
is no need to allocate extra space for the stub functions.

Reviewers: lhames, reames, maksfb

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14676

llvm-svn: 253920
2015-11-23 21:47:51 +00:00
Sanjoy Das 8082592ac9 [RuntimeDyld] Add bounds checking to SectionEntry::advanceStubOffset
Summary:
Change SectionEntry to keep track of the size of its underlying
allocation, and use that to bounds check advanceStubOffset.

Reviewers: lhames, andrew.w.kaylor, reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14675

llvm-svn: 253919
2015-11-23 21:47:46 +00:00
Sanjoy Das 277776a520 [RuntimeDyld] Add accessors to `SectionEntry`; NFC
Summary:
Remove naked access to the data members in `SectionEntry` and route
accesses through accessor functions.  This makes it obvious how the
instances of the class are used, and will also facilitate adding bounds
checking to `advanceStubOffset` in a later change.

Reviewers: lhames, loladiro, andrew.w.kaylor

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14674

llvm-svn: 253918
2015-11-23 21:47:41 +00:00
Lang Hames a32d71be4c [RuntimeDyld] Add support for absolute symbols.
llvm-svn: 250639
2015-10-18 01:41:37 +00:00
Lang Hames 2e88f4fc5f [RuntimeDyld] Make LoadedObjectInfo::getLoadedSectionAddress take a SectionRef
rather than a string section name.

llvm-svn: 243456
2015-07-28 17:52:11 +00:00
Petar Jovanovic 9720283e99 [Mips64] Add support for MCJIT for MIPS64r2 and MIPS64r6
Add support for resolving MIPS64r2 and MIPS64r6 relocations in MCJIT.

Patch by Vladimir Radosavljevic.

Differential Revision: http://reviews.llvm.org/D9667

llvm-svn: 238424
2015-05-28 13:48:41 +00:00
Keno Fischer c780e8ebcc Make it easier to use DwarfContext with MCJIT
Summary:
This supersedes http://reviews.llvm.org/D4010, hopefully properly
dealing with the JIT case and also adds an actual test case.
DwarfContext was basically already usable for the JIT (and back when
we were overwriting ELF files it actually worked out of the box by
accident), but in order to resolve relocations correctly it needs
to know the load address of the section.
Rather than trying to get this out of the ObjectFile or requiring
the user to create a new ObjectFile just to get some debug info,
this adds the capability to pass in that info directly.
As part of this I separated out part of the LoadedObjectInfo struct
from RuntimeDyld, since it is now required at a higher layer.

Reviewers: lhames, echristo

Reviewed By: echristo

Subscribers: vtjnash, friss, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D6961

llvm-svn: 237961
2015-05-21 21:24:32 +00:00
Lang Hames ccc588e004 [RuntimeDyld] Make SectionEntry's Name field a std::string.
StringRef is unsafe here, since SectionEntry instances can outlive the
ObjectFile instances they are created from.

llvm-svn: 234910
2015-04-14 17:13:10 +00:00
Keno Fischer 02628def32 [RuntimeDyldELF] Improve GOT support
Summary:
This is the first in a series of patches to eventually add support for TLS relocations to RuntimeDyld. This patch resolves an issue in the current GOT handling, where GOT entries would be reused between object files, which leads to the same situation that necessitates the GOT in the first place, i.e. that the 32-bit offset can not cover all of the address space. Thus this patch makes the GOT object-file-local.
Unfortunately, this still isn't quite enough, because the MemoryManager does not yet guarantee that sections are allocated sufficiently close to each other, even if they belong to the same object file. To address this concern, this patch also adds a small API abstraction on top of the GOT allocation mechanism that will allow (temporarily, until the MemoryManager is improved) using the stub mechanism instead of allocating a different section. The actual switch from separate section to stub mechanism will be part of a follow-on commit, so that it can be easily reverted independently at the appropriate time.

Test Plan: Includes a test case where the GOT of two object files is artificially forced to be apart by several GB.

Reviewers: lhames

Reviewed By: lhames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8813

llvm-svn: 234839
2015-04-14 02:10:35 +00:00
Lang Hames 633fe146e9 [MCJIT][Orc] Refactor RTDyldMemoryManager, weave RuntimeDyld::SymbolInfo through
MCJIT.

This patch decouples the two responsibilities of the RTDyldMemoryManager class,
memory management and symbol resolution, into two new classes:
RuntimeDyld::MemoryManager and RuntimeDyld::SymbolResolver.

The symbol resolution interface is modified slightly, from:

  uint64_t getSymbolAddress(const std::string &Name);

to:

  RuntimeDyld::SymbolInfo findSymbol(const std::string &Name);

The latter passes symbol flags along with symbol addresses, allowing RuntimeDyld
and others to reason about non-strong/non-exported symbols.


The memory management interface removes the following method:

  void notifyObjectLoaded(ExecutionEngine *EE,
                          const object::ObjectFile &) {}

as it is not related to memory management. (Note: Backwards compatibility *is*
maintained for this method in MCJIT and OrcMCJITReplacement, see below).


The RTDyldMemoryManager class remains in-tree for backwards compatibility.
It inherits directly from RuntimeDyld::SymbolResolver, and indirectly from
RuntimeDyld::MemoryManager via the new MCJITMemoryManager class, which
just subclasses RuntimeDyld::MemoryManager and reintroduces the
notifyObjectLoaded method for backwards compatibility).

The EngineBuilder class retains the existing method:

  EngineBuilder&
  setMCJITMemoryManager(std::unique_ptr<RTDyldMemoryManager> mcjmm);

and includes two new methods:

  EngineBuilder&
  setMemoryManager(std::unique_ptr<MCJITMemoryManager> MM);

  EngineBuilder&
  setSymbolResolver(std::unique_ptr<RuntimeDyld::SymbolResolver> SR);

Clients should use EITHER:

A single call to setMCJITMemoryManager with an RTDyldMemoryManager.

OR (exclusive)

One call each to each of setMemoryManager and setSymbolResolver.

This patch should be fully compatible with existing uses of RTDyldMemoryManager.
If it is not it should be considered a bug, and the patch either fixed or
reverted.

If clients find the new API to be an improvement the goal will be to deprecate
and eventually remove the RTDyldMemoryManager class in favor of the new classes.

llvm-svn: 233509
2015-03-30 03:37:06 +00:00
Lang Hames b11860362d [Orc][MCJIT][RuntimeDyld] Re-apply r231726 and r231724 with fix suggested by
Dave Blaikie. Thanks Dave!

llvm-svn: 231896
2015-03-11 00:43:26 +00:00
Eric Christopher 0c3c1893c4 Temporarily revert r231726 and r231724 as they're breaking the build.:
Author: Lang Hames <lhames@gmail.com>
Date:   Mon Mar 9 23:51:09 2015 +0000

    [Orc][MCJIT][RuntimeDyld] Add header that was accidentally left out of r231724.

Author: Lang Hames <lhames@gmail.com>
Date:   Mon Mar 9 23:44:13 2015 +0000

    [Orc][MCJIT][RuntimeDyld] Add symbol flags to symbols in RuntimeDyld. Thread the
    new types through MCJIT and Orc.

    In particular, add a 'weak' flag. When plumbed through RTDyldMemoryManager, this
    will allow us to distinguish between weak and strong definitions and find the
    right ones during symbol resolution.

llvm-svn: 231731
2015-03-10 00:33:27 +00:00
Lang Hames 3197fb4a89 [Orc][MCJIT][RuntimeDyld] Add symbol flags to symbols in RuntimeDyld. Thread the
new types through MCJIT and Orc.

In particular, add a 'weak' flag. When plumbed through RTDyldMemoryManager, this
will allow us to distinguish between weak and strong definitions and find the
right ones during symbol resolution.

llvm-svn: 231724
2015-03-09 23:44:13 +00:00