Commit Graph

353 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith
94512f24de DebugInfo: Remove MDString-based type references
Eliminate DITypeIdentifierMap and make DITypeRef a thin wrapper around
DIType*.  It is no longer legal to refer to a DICompositeType by its
'identifier:', and DIBuilder no longer retains all types with an
'identifier:' automatically.

Aside from the bitcode upgrade, this is mainly removing logic to resolve
an MDString-based reference to an actualy DIType.  The commits leading
up to this have made the implicit type map in DICompileUnit's
'retainedTypes:' field superfluous.

This does not remove DITypeRef, DIScopeRef, DINodeRef, and
DITypeRefArray, or stop using them in DI-related metadata.  Although as
of this commit they aren't serving a useful purpose, there are patchces
under review to reuse them for CodeView support.

The tests in LLVM were updated with deref-typerefs.sh, which is attached
to the thread "[RFC] Lazy-loading of debug info metadata":

  http://lists.llvm.org/pipermail/llvm-dev/2016-April/098318.html

llvm-svn: 267296
2016-04-23 21:08:00 +00:00
Rafael Espindola
7e0cfdf745 Fix recursive -only-needed.
We were assuming that only linkonce_odr GVs were lazy linked.

llvm-svn: 266995
2016-04-21 14:56:33 +00:00
Mehdi Amini
857b9f0901 ThinLTO/ModuleLinker: add a flag to not always pull-in linkonce when performing importing
Summary:
The function importer already decided what symbols need to be pulled
in. Also these magically added ones will not be in the export list
for the source module, which can confuse the internalizer for
instance.

Reviewers: tejohnson, rafael

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19096

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266948
2016-04-21 01:59:39 +00:00
Mehdi Amini
45e686121e ThinLTO: never promote as external weak
This linkage is *not* intended to express that a declaration refers
to a weak symbol, but that the symbol might not be present at link
time. I don't believe it was the intent.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266856
2016-04-20 04:18:11 +00:00
Duncan P. N. Exon Smith
2288252887 IR: Enable debug info type ODR uniquing for forward decls
Add a new method, DICompositeType::buildODRType, that will create or
mutate the DICompositeType for a given ODR identifier, and use it in
LLParser and BitcodeReader instead of DICompositeType::getODRType.

The logic is as follows:

  - If there's no node, create one with the given arguments.
  - Else, if the current node is a forward declaration and the new
    arguments would create a definition, mutate the node to match the
    new arguments.
  - Else, return the old node.

This adds a missing feature supported by the current DITypeIdentifierMap
(which I'm slowly making redudant).  The only remaining difference is
that the DITypeIdentifierMap has a "the-last-one-wins" rule, whereas
DICompositeType::buildODRType has a "the-first-one-wins" rule.

For now I'm leaving behind DICompositeType::getODRType since it has
obvious, low-level semantics that are convenient for unit testing.

llvm-svn: 266786
2016-04-19 18:00:19 +00:00
Duncan P. N. Exon Smith
b39d835190 Linker: Simplify test/Linker/dicompositetype-unique.ll, NFC
Simplify the test logic a little, sharing logic between the two linking
directions by specifying -check-prefix multiple times.  Now it's more
obvious what's hte same and different between the two directions, and
there is less CHECK duplication.  This is a prep for expanding the test.

llvm-svn: 266773
2016-04-19 17:43:43 +00:00
Mehdi Amini
d8a373b882 ModuleLinker: Do not import linkonce/weak as "external_weak"
Summary:
There is no reason to have a weak reference because the external
definition will be weak.

Reviewers: rafael

Subscribers: llvm-commits, tejohnson

Differential Revision: http://reviews.llvm.org/D19267

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266750
2016-04-19 16:11:05 +00:00
Duncan P. N. Exon Smith
e6893b5521 IR: getOrInsertODRUniquedType => DICompositeType::getODRType, NFC
Lift the API for debug info ODR type uniquing up a layer.  Instead of
clients managing the map directly on the LLVMContext, add a static
method to DICompositeType called getODRType and handle the map in the
background.  Also adds DICompositeType::getODRTypeIfExists, so far just
for convenience in the unit tests.

This simplifies the logic in LLParser and BitcodeReader.  Because of
argument spam there are actually a few more lines of code now; I'll see
if I come up with a reasonable way to clean that up.

llvm-svn: 266742
2016-04-19 14:55:09 +00:00
Paul Robinson
28e9fd46e3 [DWARF] Force a linkage_name on an inlined subprogram's abstract origin.
When we suppress linkage names, for a non-inlined subprogram the name
can still be found in the object-file symbol table, because we have
the code address of the subprogram.  This is not necessarily the case
for an inlined subprogram, so we still want to emit the linkage name
in the DWARF.  Put this on the abstract-origin DIE because it's common
to all inlined instances.

Differential Revision: http://reviews.llvm.org/D18706

llvm-svn: 266692
2016-04-18 22:41:41 +00:00
Duncan P. N. Exon Smith
0c4233db2f IR: Use an explicit map for debug info type uniquing
Rather than relying on the structural equivalence of DICompositeType to
merge type definitions, use an explicit map on the LLVMContext that
LLParser and BitcodeReader consult when constructing new nodes.
Each non-forward-declaration DICompositeType with a non-empty
'identifier:' field is stored/loaded from the type map, and the first
definiton will "win".

This map is opt-in: clients that expect ODR types from different modules
to be merged must call LLVMContext::ensureDITypeMap.

  - Clients that just happen to load more than one Module in the same
    LLVMContext won't magically merge types.

  - Clients (like LTO) that want to continue to merge types based on ODR
    identifiers should opt-in immediately.

I have updated LTOCodeGenerator.cpp, the two "linking" spots in
gold-plugin.cpp, and llvm-link (unless -disable-debug-info-type-map) to
set this.

With this in place, it will be straightforward to remove the DITypeRef
concept (i.e., referencing types by their 'identifier:' string rather
than pointing at them directly).

llvm-svn: 266549
2016-04-17 03:58:21 +00:00
Duncan P. N. Exon Smith
a1404a67fa IR: Use ODR to unique DICompositeType members
Merge members that are describing the same member of the same ODR type,
even if other bits differ.  If the file or line differ, we don't care;
if anything else differs, it's an ODR violation (and we still don't
really care).

For DISubprogram declarations, this looks at the LinkageName and Scope.
For DW_TAG_member instances of DIDerivedType, this looks at the Name and
Scope.  In both cases, we know that the Scope follows ODR rules if it
has a non-empty identifier.

llvm-svn: 266548
2016-04-17 02:30:20 +00:00
Duncan P. N. Exon Smith
75936fee09 Linker: Clarify test/Linker/type-unique-odr-a.ll, NFC
Split up the long RUN and clarify the CHECK lines:

  - Explicitly confirm there are no other subprograms inside of "A".

  - Remove checks for "bar" and "baz", which were just implicitly
    checking that there were no other subprograms inside of "A".

This prepares for adding a RUN line which links the two files in the
opposite direction.

llvm-svn: 266543
2016-04-17 00:26:17 +00:00
Adrian Prantl
fb3abba237 [PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

llvm-svn: 266446
2016-04-15 15:57:41 +00:00
Mehdi Amini
03a2cdacee Move summary creation out of llvm-as into opt
Summary:
Let keep llvm-as "dumb": it converts textual IR to bitcode. This
commit removes the dependency from llvm-as to libLLVMAnalysis.
We'll add back summary in llvm-as if we get to a textual
representation for it at some point. In the meantime, opt seems
like a better place for that.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19032

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266131
2016-04-12 21:35:18 +00:00
Mehdi Amini
bf78d0ed58 ThinLTO renaming: use module hash instead of position in the summary
This is more robust to changes in the link ordering.

Differential Revision: http://reviews.llvm.org/D18946

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266018
2016-04-11 23:26:46 +00:00
Adrian Prantl
d4a72b1280 Legalize the debug info in this testcase in anticipation of future Verifier improvements.
llvm-svn: 266017
2016-04-11 23:26:31 +00:00
Adrian Prantl
8e51262d6a Add missing DICompileUnit to this testcase
llvm-svn: 265995
2016-04-11 20:58:57 +00:00
Adrian Prantl
dac3cdd613 More upgrading of old- and very-old-style debug info in testcases.
llvm-svn: 265953
2016-04-11 15:53:44 +00:00
Adrian Prantl
1653aa9f14 testcase gardening: update the emissionKind enum to the new syntax. (NFC)
llvm-svn: 265081
2016-04-01 00:16:49 +00:00
Adrian Prantl
3e537cddb9 Move the DebugEmissionKind enum from DIBuilder into DICompileUnit.
This mostly cosmetic patch moves the DebugEmissionKind enum from DIBuilder
into DICompileUnit. DIBuilder is not the right place for this enum to live
in — a metadata consumer should not have to include DIBuilder.h.
I also added a Verifier check that checks that the emission kind of a
DICompileUnit is actually legal.

http://reviews.llvm.org/D18612
<rdar://problem/25427165>

llvm-svn: 265077
2016-03-31 23:56:58 +00:00
Adrian Prantl
cbf8114bc1 Upgrade some wildly anachronistic debug info in testcases.
llvm-svn: 264797
2016-03-29 22:34:30 +00:00
Rafael Espindola
832680bbb5 Fix another case where we were unconditionally linking linkonce GVs.
With this I think that now llvm-link,  lld and the gold plugin should
agree on which symbol is kept.

llvm-svn: 264292
2016-03-24 15:23:01 +00:00
Rafael Espindola
e8152e3f49 Fix resolution of linkonce symbols in comdats.
After comdat processing, the symbols still go through regular symbol
resolution.

We were not doing it for linkonce symbols since they are lazy linked.

This fixes pr27044.

llvm-svn: 264288
2016-03-24 14:58:44 +00:00
Rafael Espindola
c65e0390b0 Fix lazy linking of comdat members.
If not for lazy linking of linkonce GVs, comdats are just a
preprocessing before symbol resolution.

Lazy linking complicates it since when we pick a visible member of
comdat, we have to make sure the rest of it passes symbol resolution
too.

llvm-svn: 264223
2016-03-24 00:06:03 +00:00
Rafael Espindola
e3e05be155 Fix logic for which symbols to keep with comdats.
If a comdat is dropped, all symbols in it are dropped.
If a comdat is kept, the symbols survive to pass regular symbol
resolution.
With this patch we do that for all global symbols.

The added test is a copy of test/tools/gold/X86/comdat.ll that we now
pass.

llvm-svn: 264192
2016-03-23 21:16:33 +00:00
Rafael Espindola
981c18bd80 Drop comdats from the dst module if they are not selected.
A really unfortunate design of llvm-link and related libraries is that
they operate one module at a time.

This means they can copy a GV to the destination module that should not
be there in the final result because a later bitcode file takes
precedence.

We already handled cases like a strong GV replacing a weak for example.

One case that is not currently handled is a comdat replacing another.
This doesn't happen in ELF, but with COFF largest selection kind it is
possible.

In "llvm-link a.ll b.ll" if the selected comdat was from a.ll,
everything will work and we will not copy the comdat from b.ll.

But if we run "llvm-link b.ll a.ll", we fail to delete the already
copied comdat from b.ll. This patch fixes that.

llvm-svn: 264103
2016-03-22 21:35:47 +00:00
Mehdi Amini
03f4fda76b Rework linkInModule(), making it oblivious to ThinLTO
Summary:
ThinLTO is relying on linkInModule to import selected function.
However a lot of "magic" was hidden in linkInModule and the IRMover,
who would rename and promote global variables on the fly.

This is moving to an approach where the steps are decoupled and the
client is reponsible to specify the list of globals to import.
As a consequence some test are changed because they were relying on
the previous behavior which was importing the definition of *every*
single global without control on the client side.
Now the burden is on the client to decide if a global has to be imported
or not.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18122

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 263863
2016-03-19 00:40:31 +00:00
Teresa Johnson
89e5e1dadb [ThinLTO] Renaming of function index to module summary index (NFC)
(Resubmitting after fixing missing file issue)

With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.

A companion clang patch will immediately succeed this patch to reflect
this renaming.

llvm-svn: 263513
2016-03-15 00:04:37 +00:00
Teresa Johnson
6632706d71 Revert "[ThinLTO] Renaming of function index to module summary index (NFC)"
This reverts commit r263490. Missed a file.

llvm-svn: 263493
2016-03-14 21:18:10 +00:00
Teresa Johnson
7f5c7bac22 [ThinLTO] Renaming of function index to module summary index (NFC)
With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.

A companion clang patch will immediately succeed this patch to reflect
this renaming.

llvm-svn: 263490
2016-03-14 21:05:56 +00:00
Teresa Johnson
fc270dff80 [ThinLTO] Remove imported available externally defs from comdats.
Summary:
Available externally definitions are considered declarations for the
linker and eventually dropped. As such they are not allowed to be
in comdats. Remove any such imported functions from comdats.

Reviewers: rafael

Subscribers: davidxl, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D16120

llvm-svn: 260122
2016-02-08 18:47:20 +00:00
Rafael Espindola
1cc73a0cb5 Add a test for r258362.
Thanks to Mehdi for finding it.

llvm-svn: 259394
2016-02-01 19:56:12 +00:00
Teresa Johnson
a52cfbb4e3 [ThinLTO] Find all needed metadata when linking metadata as postpass
For metadata postpass linking, after importing all functions, we need
to recursively walk through any nodes reached via imported functions to
locate needed subprogram metadata. Some might only be reached indirectly
via the variable list for an inlined function.

llvm-svn: 258728
2016-01-25 22:04:56 +00:00
Teresa Johnson
8b2ed4fc5e [ThinLTO] Handle DISubprogram reached indirectly from DIImportedEntity
Extend fix for PR26037 to identify DISubprogram reached from a
DIImportedEntity via a DILexicalBlock.

llvm-svn: 258722
2016-01-25 21:29:55 +00:00
Teresa Johnson
c88ea8cc50 Revert obsolete llvm-link -preserve-modules option/test
This testing mode is now obsolete with the change to linkInModule
to take a std::unique_ptr to Module.

llvm-svn: 258399
2016-01-21 14:28:52 +00:00
Evgeniy Stepanov
6c4fc98afa Fix PR26152.
Fix the condition for when the new global takes over the name of
the existing one to be the negation of the condition for the new
global to get internal linkage.

llvm-svn: 258355
2016-01-20 22:05:50 +00:00
Keno Fischer
927308d763 Reapply r257105 "[Verifier] Check that debug values have proper size"
I originally reapplied this in 257550, but had to revert again due to bot
breakage. The only change in this version is to allow either the TypeSize
or the TypeAllocSize of the variable to be the one represented in debug info
(hopefully in the future we can figure out how to encode the difference).
Additionally, several bot failures following r257550, were due to
optimizer bugs now fixed in r257787 and r257795.

r257550 commit message was:

```
The follow extra changes were made to test cases:

Manually making the variable be the actual type instead of a pointer
to avoid pointer-size differences in generic code:

    LLVM :: DebugInfo/Generic/2010-03-24-MemberFn.ll
    LLVM :: DebugInfo/Generic/2010-04-06-NestedFnDbgInfo.ll
    LLVM :: DebugInfo/Generic/2010-05-03-DisableFramePtr.ll
    LLVM :: DebugInfo/Generic/varargs.ll

Delete sizing information from debug info for the same reason
(but the presence of the pointer was important to the test case):

    LLVM :: DebugInfo/Generic/restrict.ll
    LLVM :: DebugInfo/Generic/tu-composite.ll
    LLVM :: Linker/type-unique-type-array-a.ll
    LLVM :: Linker/type-unique-simple2.ll

Fixing an incorrect DW_OP_deref

    LLVM :: DebugInfo/Generic/2010-05-03-OriginDIE.ll

Fixing a missing DW_OP_deref

    LLVM :: DebugInfo/Generic/incorrect-variable-debugloc.ll

Additionally, clang should no longer complain during bootstrap should no
longer happen after r257534.

The original commit message was:
``
Summary:
Teach the Verifier to make sure that the storage size given to llvm.dbg.declare
or the value size given to llvm.dbg.value agree with what is declared in
DebugInfo. This is implicitly assumed in a number of passes (e.g. in SROA).
Additionally this catches a number of common mistakes, such as passing a
pointer when a value was intended or vice versa.

One complication comes from stack coloring which modifies the original IR when
it merges allocas in order to make sure that if AA falls back to the IR it gets
the correct result. However, given this new invariant, indiscriminately
replacing one alloca by a different (differently sized one) is no longer valid.
Fix this by just undefing out any use of the alloca in a dbg.declare in this
case.

Additionally, I had to fix a number of test cases. Of particular note:
- I regenerated dbg-changes-codegen-branch-folding.ll from the given source as
  it was affected by the bug fixed in r256077
- two-cus-from-same-file.ll was changed to avoid having a variable-typed debug
  variable as that would depend on the target, even though this test is
  supposed to be generic
- I had to manually declared size/align for reference type. See also the
  discussion for D14275/r253186.
- fpstack-debuginstr-kill.ll required changing `double` to `long double`
- most others were just a question of adding OP_deref
``

```

llvm-svn: 257850
2016-01-15 00:46:17 +00:00
Keno Fischer
97a5fb3666 Re-Revert r257105 (Verifier debug info changes)
While I investigate some new buildbot failures. This was originally reapplied
as r257550 and r257558.

llvm-svn: 257563
2016-01-13 02:31:14 +00:00
Keno Fischer
d8825d5008 Reapply r257105 "[Verifier] Check that debug values have proper size"
The follow extra changes were made to test cases:

Manually making the variable be the actual type instead of a pointer
to avoid pointer-size differences in generic code:

    LLVM :: DebugInfo/Generic/2010-03-24-MemberFn.ll
    LLVM :: DebugInfo/Generic/2010-04-06-NestedFnDbgInfo.ll
    LLVM :: DebugInfo/Generic/2010-05-03-DisableFramePtr.ll
    LLVM :: DebugInfo/Generic/varargs.ll

Delete sizing information from debug info for the same reason
(but the presence of the pointer was important to the test case):

    LLVM :: DebugInfo/Generic/restrict.ll
    LLVM :: DebugInfo/Generic/tu-composite.ll
    LLVM :: Linker/type-unique-type-array-a.ll
    LLVM :: Linker/type-unique-simple2.ll

Fixing an incorrect DW_OP_deref

    LLVM :: DebugInfo/Generic/2010-05-03-OriginDIE.ll

Fixing a missing DW_OP_deref

    LLVM :: DebugInfo/Generic/incorrect-variable-debugloc.ll

Additionally, clang should no longer complain during bootstrap should no
longer happen after r257534.

The original commit message was:
```
Summary:
Teach the Verifier to make sure that the storage size given to llvm.dbg.declare
or the value size given to llvm.dbg.value agree with what is declared in
DebugInfo. This is implicitly assumed in a number of passes (e.g. in SROA).
Additionally this catches a number of common mistakes, such as passing a
pointer when a value was intended or vice versa.

One complication comes from stack coloring which modifies the original IR when
it merges allocas in order to make sure that if AA falls back to the IR it gets
the correct result. However, given this new invariant, indiscriminately
replacing one alloca by a different (differently sized one) is no longer valid.
Fix this by just undefing out any use of the alloca in a dbg.declare in this
case.

Additionally, I had to fix a number of test cases. Of particular note:
- I regenerated dbg-changes-codegen-branch-folding.ll from the given source as
  it was affected by the bug fixed in r256077
- two-cus-from-same-file.ll was changed to avoid having a variable-typed debug
  variable as that would depend on the target, even though this test is
  supposed to be generic
- I had to manually declared size/align for reference type. See also the
  discussion for D14275/r253186.
- fpstack-debuginstr-kill.ll required changing `double` to `long double`
- most others were just a question of adding OP_deref
```

llvm-svn: 257550
2016-01-13 00:31:44 +00:00
Ahmed Bougacha
3c06bcb519 [Linker] Also treat a DIImportedEntity scope DISubprogram as needed.
Follow-up to r257000: DIImportedEntity can reach a DISubprogram via
its entity, but also via its scope. Handle the latter case as well.

PR26037.

llvm-svn: 257019
2016-01-07 03:14:59 +00:00
Teresa Johnson
018d695dd9 Always treat DISubprogram reached by DIImportedEntity as needed.
It is illegal to have a null entity in a DIImportedEntity, so
we must link in a DISubprogram metadata node referenced by one,
even if the associated function is not linked in or inlined anywhere.

Fixes PR26037.

llvm-svn: 257000
2016-01-07 00:06:27 +00:00
Teresa Johnson
a03b8bd4f9 [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
0dce8d436c [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
Rafael Espindola
5b397256de 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
43562b355d Fix another case where the linkage was not set.
llvm-svn: 255272
2015-12-10 18:44:26 +00:00
Rafael Espindola
c944447e56 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
88c4494d79 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
7e77ee21fb Add a test showing that we internalize lazily linked GVs.
llvm-svn: 254989
2015-12-08 02:38:14 +00:00
Rafael Espindola
d87ec5e77d Simplify test. NFC.
llvm-svn: 254987
2015-12-08 02:29:45 +00:00
Rafael Espindola
1d4a6cc6f5 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