Commit Graph

571 Commits

Author SHA1 Message Date
Teresa Johnson d213aa469e Handle empty Subprogram list when linking metadata.
Use an iterator that handles an empty subprogram list.

Fixes PR25915.

llvm-svn: 256224
2015-12-22 01:17:19 +00:00
Teresa Johnson 4f04d85fa6 [ThinLTO] Rename variable to reflect bulk importing change (NFC)
llvm-svn: 256171
2015-12-21 17:33:24 +00:00
Teresa Johnson 4034d55158 Remove unused functions from ModuleLinker (NFC)
Remove a couple ModuleLinker methods and a related static function that
are no longer used after the linker split.

llvm-svn: 256162
2015-12-21 15:49:59 +00:00
Rafael Espindola 18c63b0f18 Drop support for dematerializing.
It was only used on lib/Linker and the use was "dead" since it was used on a
function the IRMover had just moved.

llvm-svn: 256019
2015-12-18 19:57:26 +00:00
Teresa Johnson bef543635a Rename variables to reflect linker split (NFC)
Renamed variables to be more reflective of whether they are
an instance of Linker, IRLinker or ModuleLinker. Also fix a stale
comment.

llvm-svn: 256011
2015-12-18 19:28:59 +00:00
Teresa Johnson 0e7c82cb69 [ThinLTO/LTO] Don't link in unneeded metadata
Summary:
Third patch split out from http://reviews.llvm.org/D14752.

Only map in needed DISubroutine metadata (imported or otherwise linked
in functions and other DISubroutine referenced by inlined instructions).
This is supported for ThinLTO, LTO and llvm-link --only-needed, with
associated tests for each one.

Depends on D14838.

Reviewers: dexonsmith, joker.eph

Subscribers: davidxl, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D14843

llvm-svn: 256003
2015-12-18 17:51:37 +00:00
Teresa Johnson e5a6191732 [ThinLTO] Metadata linking for imported functions
Summary:
Second patch split out from http://reviews.llvm.org/D14752.

Maps metadata as a post-pass from each module when importing complete,
suturing up final metadata to the temporary metadata left on the
imported instructions.

This entails saving the mapping from bitcode value id to temporary
metadata in the importing pass, and from bitcode value id to final
metadata during the metadata linking postpass.

Depends on D14825.

Reviewers: dexonsmith, joker.eph

Subscribers: davidxl, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D14838

llvm-svn: 255909
2015-12-17 17:14:09 +00:00
Teresa Johnson 4a9bf5872c Mark a couple ModuleLinker member functions as const (NFC)
llvm-svn: 255903
2015-12-17 16:34:53 +00:00
Rafael Espindola 434e956181 Change linkInModule to take a std::unique_ptr.
Passing in a std::unique_ptr should help find errors when the module
is used after being linked into another module.

llvm-svn: 255842
2015-12-16 23:16:33 +00:00
Rafael Espindola 9d2bfc4874 Use diagnostic handler in the LLVMContext
This patch converts code that has access to a LLVMContext to not take a
diagnostic handler.

This has a few advantages

* It is easier to use a consistent diagnostic handler in a single program.
* Less clutter since we are not passing a handler around.

It does make it a bit awkward to implement some C APIs that return a
diagnostic string. I will propose new versions of these APIs and
deprecate the current ones.

llvm-svn: 255571
2015-12-14 23:17:03 +00:00
Rafael Espindola a8547d35e9 Fix another case where the linkage was not set.
llvm-svn: 255272
2015-12-10 18:44:26 +00:00
Rafael Espindola f81c7b03a0 Avoid undefined behavior when vector is empty.
Found by ubsan.

llvm-svn: 255258
2015-12-10 16:35:06 +00:00
Rafael Espindola caabe22832 Slit lib/Linker in two.
A linker normally has two stages: symbol resolution and "moving stuff".

In lib/Linker there is the complication of lazy linking some globals,
but it was still far more mixed than it needed to.

This splits the linker into a lower level IRMover and the linker proper.
The IRMover just takes a list of globals to move and a callback that
lets the user control what is lazy linked.

The main motivation is that now tools/gold (and soon lld) can use their
own symbol resolution to instruct IRMover what to do.

llvm-svn: 255254
2015-12-10 14:19:35 +00:00
Rafael Espindola ed11bd286f Synchronize the logic for deciding to link a gv.
We were deciding to not link an available_externally gv over a
declaration, but then copying over the body anyway.

llvm-svn: 255169
2015-12-09 22:44:00 +00:00
Rafael Espindola d57f9f0c90 Move all private members together. NFC.
llvm-svn: 255021
2015-12-08 14:54:49 +00:00
Rafael Espindola c6c9735f83 Factor two calls to a common location.
llvm-svn: 254967
2015-12-07 23:32:39 +00:00
Rafael Espindola e811c7b5ad Simplify the error handling a bit. NFC.
llvm-svn: 254952
2015-12-07 21:28:22 +00:00
Rafael Espindola bd03c50336 Link declaration lazily.
We already linked available_externally and linkonce lazily, this just
adds declarations to the list.

llvm-svn: 254917
2015-12-07 16:31:41 +00:00
Rafael Espindola a1240d8cb3 Change how the linker handles the old llvm.global_ctors.
Now instead of changing it to the new format and then linking, it just
handles the old format while copying it over.

The main differences are:

* There is no rauw in the source module.
* An old format input is always upgraded.

The first item helps with having a sane API that passes in a GV list to
the linker.

The second one is a small step in deprecating the old format.

llvm-svn: 254907
2015-12-07 13:24:23 +00:00
Teresa Johnson bae7e75959 [ThinLTO] Helper for performing renaming/promotion on a module
Creates a module and performs necessary renaming/promotion of locals
that may be exported to another module.

Split out of D15024.

llvm-svn: 254802
2015-12-04 23:40:22 +00:00
Rafael Espindola f49a38fc08 Always pass a diagnostic handler to the linker.
Before this patch the diagnostic handler was optional. If it was not
passed, the one in the LLVMContext was used.

That is probably not a pattern we want to follow. If each area has an
optional callback, there is a sea of callbacks and it is hard to follow
which one is called.

Doing this also found cases where the callback is a nice addition, like
testing that no errors or warnings are reported.

The other option is to always use the diagnostic handler in the
LLVMContext. That has a few problems

* To implement the C API we would have to set the diag handler and then
  set it back to the original value.
* Code that creates the context might be far away from code that wants
  the diagnostics.

I do have a patch that implements the second option and will send that as
an RFC.

llvm-svn: 254777
2015-12-04 22:08:53 +00:00
Teresa Johnson 1e20a652ee [ThinLTO] Appending linkage fixes
Summary:
Fix import from module with appending var, which cannot be imported. The
first fix is to remove an overly-aggressive error check.

The second fix is to deal with restructuring introduced to the module
linker yesterday in r254418 (actually, this fix was included already
in r254559, just added some additional cleanup).

Test by Mehdi Amini.

Reviewers: joker.eph, rafael

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D15156

llvm-svn: 254624
2015-12-03 18:20:05 +00:00
Rafael Espindola 562908bbd0 Simplify ValueMap handling.
We now just return values and let ValueMap handle the map.

llvm-svn: 254615
2015-12-03 16:36:16 +00:00
Rafael Espindola 792b7958ff Don't pass member variables to member functions. NFC.
llvm-svn: 254610
2015-12-03 14:48:20 +00:00
Mehdi Amini 7471cf81b0 Adapt comment and rename variable in ModuleLinker to describe more accurately the actual use.
Thanks Sean Silva for the suggestion.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 254582
2015-12-03 02:37:30 +00:00
Mehdi Amini 9abe1089c7 Remove "ExportingModule" from ThinLTO Index (NFC)
There is no real reason the index has to have the concept of an
exporting Module. We should be able to have one single unique
instance of the Index, and it should be read-only after creation
for the whole ThinLTO processing.
The linker plugin should be able to process multiple modules (in
parallel or in sequence) with the same index.

The only reason the ExportingModule was present seems to be to
implement hasExportedFunctions() that is used by the Module linker
to decide what to do with the current Module.
For now I replaced it with a query to the map of Modules path to
see if this module was declared in the Index and consider that if
it is the case then it is probably exporting function.
On the long term the Linker interface needs to evolve and this
call should not be needed anymore.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 254581
2015-12-03 02:37:23 +00:00
Rafael Espindola 4b5ec26373 Switch the linker to having a whitelist of GVs.
This replaces DoNotLinkFromSource with ValuesToLink. It also moves the
computation of ValuesToLink earlier.

It is a bit simpler and an important step in slitting the linker into an
ir mover and a linker proper.

The test change is because we now avoid creating dead declarations.

llvm-svn: 254559
2015-12-02 22:59:04 +00:00
Rafael Espindola 8c04472edf Delete what is now duplicated code.
Having to import an alias as declaration is not thinlto specific.

The test difference are because when we already have a decl and we are
not importing it, we just leave the decl alone.

llvm-svn: 254556
2015-12-02 22:22:24 +00:00
Rafael Espindola 0a80da0bec Also copy private linkage globals when needed.
This was an omission when handling COFF style comdats with local keys.
Should fix the sanitizer-windows bot.

llvm-svn: 254543
2015-12-02 20:57:33 +00:00
Rafael Espindola 769efe621a Don't copy information from aliasee to alias.
They are independent.

llvm-svn: 254541
2015-12-02 20:03:17 +00:00
Rafael Espindola f3518c955b Fix linking when we copy over only a decl.
We were failing to copy the fact that the GV is weak and in the case of
an alias, producing invalid IR.

llvm-svn: 254538
2015-12-02 19:30:52 +00:00
Mehdi Amini ffe2e4aae0 Change ModuleLinker to take a set of GlobalValues to import instead of a single one
For efficiency reason, when importing multiple functions for the same Module,
we can avoid reparsing it every time.

Differential Revision: http://reviews.llvm.org/D15102

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 254486
2015-12-02 04:34:28 +00:00
Rafael Espindola af714765e6 Use default member initializers.
llvm-svn: 254473
2015-12-01 23:06:26 +00:00
Rafael Espindola 6d2c313b46 Remove unnecessary getter.
llvm-svn: 254466
2015-12-01 23:01:51 +00:00
Rafael Espindola e39cd5b144 Pass down the dst GV to linkGlobalValueBody. NFC.
llvm-svn: 254465
2015-12-01 22:40:40 +00:00
Rafael Espindola edf811d68f Delete unused includes.
llvm-svn: 254457
2015-12-01 20:23:19 +00:00
Rafael Espindola e3a933af31 clang-format LinkModules.cpp.
Most of the file has been changed recently and was already clang-format
clean.

llvm-svn: 254454
2015-12-01 20:11:43 +00:00
Rafael Espindola 0e309fe860 Use references now that it is natural to do so.
The linker never takes ownership of a module or changes which module it
is refering to, making it natural to use references.

llvm-svn: 254449
2015-12-01 19:50:54 +00:00
Rafael Espindola 3b80b8854c Delete dead code.
llvm-svn: 254436
2015-12-01 18:50:35 +00:00
Rafael Espindola 4dbdceb6fc Use a forwarding constructor instead of an init method.
llvm-svn: 254435
2015-12-01 18:46:19 +00:00
Rafael Espindola 4808c6d064 Delete the setModule method from the Linker.
It was only used from LTO for a debug feature, and LTO can just create
another linker.

It is pretty odd to have a method to reset the module in the middle of a
link. It would make IdentifiedStructTypes inconsistent with the Module
for example.

llvm-svn: 254434
2015-12-01 18:41:30 +00:00
Rafael Espindola 6e8ab928d5 Make appending var linking less of a special case.
It has to be a bit special because:
* materializeInitFor is not really supposed to call replaceAllUsesWith.
  The caller has a plain variable with Dst and expects just the
  initializer to be set, not for it to be removed.
* Calling mutateType as we used to do before gets some type
  inconsistency which breaks the bitcode writer.
* If linkAppendingVarProto create a dest decl with the correct type to
  avoid the above problems, it needs to put the original dst init in
  some side table for materializeInitFor to use.

In the end the simplest solution seems to be to just have
linkAppendingVarProto do all the work and set ValueMap[SrcGV to avoid
recursion.

llvm-svn: 254424
2015-12-01 17:17:04 +00:00
Rafael Espindola baa3bf8f76 Bring r254336 back:
The difference is that now we don't error on out-of-comdat access to
internal global values. We copy them instead. This seems to match the
expectation of COFF linkers (see pr25686).

Original message:

    Start deciding earlier what to link.

    A traditional linker is roughly split in symbol resolution and
"copying
    stuff".

    The two tasks are badly mixed in lib/Linker.

    This starts splitting them apart.

    With this patch there are no direct call to linkGlobalValueBody or
    linkGlobalValueProto. Everything is linked via WapValue.

    This also includes a few fixes:
    * A GV goes undefined if the comdat is dropped (comdat11.ll).
    * We error if an internal GV goes undefined (comdat13.ll).
    * We don't link an unused comdat.

    The first two match the behavior of an ELF linker. The second one is
    equivalent to running globaldce on the input.

llvm-svn: 254418
2015-12-01 15:19:48 +00:00
Rafael Espindola e9841a6bb5 This reverts commit r254336 and r254344.
They broke a bot and I am debugging why.

llvm-svn: 254347
2015-11-30 23:54:19 +00:00
Rafael Espindola a891957002 Disable a consistency check.
Trying to figure out why it fails on a bot but passes locally.

llvm-svn: 254344
2015-11-30 23:05:25 +00:00
Rafael Espindola c109200c53 Start deciding earlier what to link.
A traditional linker is roughly split in symbol resolution and "copying
stuff".

The two tasks are badly mixed in lib/Linker.

This starts splitting them apart.

With this patch there are no direct call to linkGlobalValueBody or
linkGlobalValueProto. Everything is linked via WapValue.

This also includes a few fixes:
* A GV goes undefined if the comdat is dropped (comdat11.ll).
* We error if an internal GV goes undefined (comdat13.ll).
* We don't link an unused comdat.

The first two match the behavior of an ELF linker. The second one is
equivalent to running globaldce on the input.

llvm-svn: 254336
2015-11-30 22:01:43 +00:00
Rafael Espindola c98b20b0d6 Fix another llvm.ctors merging bug.
We were not looking past casts to see if an element should be included
or not.

llvm-svn: 254313
2015-11-30 18:54:24 +00:00
Rafael Espindola eb5e0a77b4 Simplify. NFC.
llvm-svn: 254254
2015-11-29 14:33:06 +00:00
Rafael Espindola c945c8d22e Correctly handle llvm.global_ctors merging.
We were not handling the case where an entry must be dropped and the
destination module has no llvm.global_ctors.

llvm-svn: 254241
2015-11-29 03:29:42 +00:00
Rafael Espindola 9f30fac4d8 Fix a crash when writing merged bitcode.
Playing with mutateType in here was making getValueType and getType
incompatible.

llvm-svn: 254240
2015-11-29 03:21:30 +00:00