Commit Graph

494 Commits

Author SHA1 Message Date
David Blaikie 16a2f3e302 Revert "[opaque pointer type] Pass GlobalAlias the actual pointer type rather than decomposing it into pointee type + address space"
This was a flawed change - it just caused the getElementType call to be
deferred until later, when we really need to remove it. Now that the IR
for GlobalAliases has been updated, the root cause is addressed that way
instead and this change is no longer needed (and in fact gets in the way
- because we want to pass the pointee type directly down further).

Follow up patches to push this through GlobalValue, bitcode format, etc,
will come along soon.

This reverts commit 236160.

llvm-svn: 247585
2015-09-14 18:01:59 +00:00
Artem Belevich 020d4fb17f New bitcode linker flags:
-only-needed -- link in only symbols needed by destination module
-internalize -- internalize linked symbols

Differential Revision: http://reviews.llvm.org/D12459

llvm-svn: 246561
2015-09-01 17:55:55 +00:00
Peter Collingbourne 5cd1e8d3ab Linker: Remove empty destructor.
llvm-svn: 245672
2015-08-21 04:51:24 +00:00
Duncan P. N. Exon Smith 4fb46cb818 Linker: Move distinct MDNodes instead of cloning
Instead of cloning distinct `MDNode`s when linking in a module, just
move them over.  The module linker destroys the source module, so the
old node would otherwise just be leaked on the context.  Create the new
node in place.  This also reduces the number of cloned uniqued nodes
(since it's less likely their operands have changed).

This mapping strategy is only correct when we're discarding the source,
so the linker turns it on via a ValueMapper flag, `RF_MoveDistinctMDs`.

There's nothing observable in terms of `llvm-link` output here: the
linked module should be semantically identical.

I'll be adding more 'distinct' nodes to the debug info metadata graph in
order to break uniquing cycles, so the benefits of this will partly come
in future commits.  However, we should get some gains immediately, since
we have a fair number of 'distinct' `DILocation`s being linked in.

llvm-svn: 243883
2015-08-03 17:09:38 +00:00
Alexander Kornienko f00654e31b Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.

llvm-svn: 240390
2015-06-23 09:49:53 +00:00
Peter Collingbourne ea45d834e0 Linker: Do not expect comdat to exist in source module.
llvm-svn: 240341
2015-06-22 21:46:51 +00:00
Alexander Kornienko 70bc5f1398 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
2015-06-19 15:57:42 +00:00
David Majnemer 7fddeccb8b Move the personality function from LandingPadInst to Function
The personality routine currently lives in the LandingPadInst.

This isn't desirable because:
- All LandingPadInsts in the same function must have the same
  personality routine.  This means that each LandingPadInst beyond the
  first has an operand which produces no additional information.

- There is ongoing work to introduce EH IR constructs other than
  LandingPadInst.  Moving the personality routine off of any one
  particular Instruction and onto the parent function seems a lot better
  than have N different places a personality function can sneak onto an
  exceptional function.

Differential Revision: http://reviews.llvm.org/D10429

llvm-svn: 239940
2015-06-17 20:52:32 +00:00
Yaron Keren 3bf3f1f5b9 Rangify several for loops, NFC.
llvm-svn: 239733
2015-06-15 16:20:16 +00:00
Eli Bendersky ff715e2d5e Fix returning error message in LLVMLinkModules
On error, the temporary output stream wouldn't be flushed and therefore the
caller would see an empty error message.

Patch by Antoine Pitrou

Differential Revision: http://reviews.llvm.org/D10241 

llvm-svn: 239646
2015-06-12 23:26:42 +00:00
Eric Christopher 97cb56572a While in GlobalValue fix the function(s) that don't follow the
naming convention and update users.

llvm-svn: 237461
2015-05-15 18:20:14 +00:00
David Blaikie f64246be72 [opaque pointer type] Pass GlobalAlias the actual pointer type rather than decomposing it into pointee type + address space
Many of the callers already have the pointer type anyway, and for the
couple of callers that don't it's pretty easy to call PointerType::get
on the pointee type and address space.

This avoids LLParser from using PointerType::getElementType when parsing
GlobalAliases from IR.

llvm-svn: 236160
2015-04-29 21:22:39 +00:00
Duncan P. N. Exon Smith a9308c49ef IR: Give 'DI' prefix to debug info metadata
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`.  The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.

Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one.  It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs.  YMMV of
course.

Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py.  I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three.  It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).

Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.

llvm-svn: 236120
2015-04-29 16:38:44 +00:00
Duncan P. N. Exon Smith c8d987b121 Linker: Copy over function metadata attachments
Update `lib/Linker` to handle `Function` metadata attachments.  The
attachments stick with the function body.

llvm-svn: 235786
2015-04-24 22:07:31 +00:00
Duncan P. N. Exon Smith e868123d8f Linker: Add flag to override linkage rules
Add a flag to lib/Linker (and `llvm-link`) to override linkage rules.
When set, the functions in the source module *always* replace those in
the destination module.

The `llvm-link` option is `-override=abc.ll`.  All the "regular" modules
are loaded and linked first, followed by the `-override` modules.  This
is useful for debugging workflows where some subset of the module (e.g.,
a single function) is extracted into a separate file where it's
optimized differently, before being merged back in.

Patch by Luqman Aden!

llvm-svn: 235473
2015-04-22 04:11:00 +00:00
Duncan P. N. Exon Smith 2fbe13540a DebugInfo: Delete subclasses of DIScope
Delete subclasses of (the already defunct) `DIScope`, updating users to
use the raw pointers from the `Metadata` hierarchy directly.

llvm-svn: 235356
2015-04-20 22:10:08 +00:00
Duncan P. N. Exon Smith 537b4a8159 DebugInfo: Gut DISubprogram and DILexicalBlock*
Gut the `DIDescriptor` wrappers around `MDLocalScope` subclasses.  Note
that `DILexicalBlock` wraps `MDLexicalBlockBase`, not `MDLexicalBlock`.

llvm-svn: 234850
2015-04-14 03:40:37 +00:00
Duncan P. N. Exon Smith 9d1cf4c166 IR: Stop using DIDescriptor::is*() and auto-casting
`DIDescriptor`'s subclasses allow construction from incompatible
pointers, and `DIDescriptor` defines a series of `isa<>`-like functions
(e.g., `isCompileUnit()` instead of `isa<MDCompileUnit>()`) that clients
tend to use like this:

    if (DICompileUnit(N).isCompileUnit())
      foo(DICompileUnit(N));

These construction patterns work together to make `DIDescriptor` behave
differently from normal pointers.

Instead, use built-in `isa<>`, `dyn_cast<>`, etc., and only build
`DIDescriptor`s from pointers that are valid for their type.

I've split this into a few commits for different parts of LLVM and clang
(to decrease the patch size and increase the chance of review).
Generally the changes I made were NFC, but in a few places I made things
stricter if it made sense from the surrounded code.

Eventually a follow-up commit will remove the API for the "old" way.

llvm-svn: 234255
2015-04-06 23:18:49 +00:00
Duncan P. N. Exon Smith c947892d10 Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly.  This fixes PR22792 (again).

I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`.  The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones.  Dropping the pointers first prevents them
from merging.

**** The original commit message follows. ****

Linker: Drop function pointers for overridden subprograms

Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`.  This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.

The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`?  Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.

Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists.  A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.

Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out.  We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.

This still isn't completely satisfactory.  Two flaws at least that I can
think of:

  - I still haven't found a straightforward way to make this symmetric
    in the IR.  (Interestingly, the DWARF output is already symmetric,
    and I've tested for that to be sure we don't regress.)
  - Using `DebugInfoFinder` to find the canonical subprogram for a
    function is kind of crazy.  We should just attach metadata to the
    function, like this:

        define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {

llvm-svn: 233302
2015-03-26 18:35:30 +00:00
Duncan P. N. Exon Smith 7124230682 Revert "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233164 and its testcase follow-ups in r233165,
r233207, r233214, and r233221.  It apparently unleashed an LTO bootstrap
failure, at least on Darwin:

http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto_build/3376/

I'm reproducing now.

llvm-svn: 233254
2015-03-26 05:27:45 +00:00
Duncan P. N. Exon Smith 004ced3b08 Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`.  This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.

The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`?  Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.

Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists.  A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.

Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out.  We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.

This still isn't completely satisfactory.  Two flaws at least that I can
think of:

  - I still haven't found a straightforward way to make this symmetric
    in the IR.  (Interestingly, the DWARF output is already symmetric,
    and I've tested for that to be sure we don't regress.)
  - Using `DebugInfoFinder` to find the canonical subprogram for a
    function is kind of crazy.  We should just attach metadata to the
    function, like this:

        define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {

llvm-svn: 233164
2015-03-25 02:26:32 +00:00
Mehdi Amini a28d91d81b DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231740
2015-03-10 02:37:25 +00:00
Rafael Espindola a5b9e1cf39 Remember to move a type to the correct set when setting the body.
We would set the body of a struct type (therefore making it non-opaque)
but were forgetting to move it to the non-opaque set.

Fixes pr22807.

llvm-svn: 231442
2015-03-06 00:50:21 +00:00
Mehdi Amini 46a43556db Make DataLayout Non-Optional in the Module
Summary:
DataLayout keeps the string used for its creation.

As a side effect it is no longer needed in the Module.
This is "almost" NFC, the string is no longer
canonicalized, you can't rely on two "equals" DataLayout
having the same string returned by getStringRepresentation().

Get rid of DataLayoutPass: the DataLayout is in the Module

The DataLayout is "per-module", let's enforce this by not
duplicating it more than necessary.
One more step toward non-optionality of the DataLayout in the
module.

Make DataLayout Non-Optional in the Module

Module->getDataLayout() will never returns nullptr anymore.

Reviewers: echristo

Subscribers: resistor, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D7992

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231270
2015-03-04 18:43:29 +00:00
Juergen Ributzka a57d588cb7 Restore LLVMLinkModules C API until it is properly deprecated.
Add the enum "LLVMLinkerMode" back for backwards-compatibility and add the
linker mode parameter back to the "LLVMLinkModules" function. The paramter is
ignored and has no effect.

Patch provided by: Filip Pizlo
Reviewed by: Rafael and Sean

llvm-svn: 230988
2015-03-02 18:59:38 +00:00
Manman Ren 6487ce955a [LTO API] add lto_codegen_set_module to set the destination module.
When debugging LTO issues with ld64, we use -save-temps to save the merged
optimized bitcode file, then invoke ld64 again on the single bitcode file to
speed up debugging code generation passes and ld64 stuff after code generation.

llvm linking a single bitcode file via lto_codegen_add_module will generate a
different bitcode file from the single input. With the newly-added
lto_codegen_set_module, we can make sure the destination module is the same as
the input.

lto_codegen_set_module will transfer the ownship of the module to code
generator.

rdar://19024554

llvm-svn: 230290
2015-02-24 00:45:56 +00:00
Benjamin Kramer 6cd780ff21 Prefer SmallVector::append/insert over push_back loops.
Same functionality, but hoists the vector growth out of the loop.

llvm-svn: 229500
2015-02-17 15:29:18 +00:00
Akira Hatanaka c43df5187c [LinkModules] Change the way ModuleLinker merges triples.
This commit makes the following changes:

- Stop issuing a warning when the triples' string representations do not match
  exactly if the Triple objects generated from the strings compare equal.
 
- On Apple platforms, choose the triple that has the larger minimum version
  number. 

rdar://problem/16743513

Differential Revision: http://reviews.llvm.org/D7591

llvm-svn: 228999
2015-02-13 00:40:41 +00:00
Manman Ren dab999d54f [llvm link] Destroy ConstantArrays in LLVMContext if they are not used.
ConstantArrays constructed during linking can cause quadratic memory
explosion. An example is the ConstantArrays constructed when linking in
GlobalVariables with appending linkage.

Releasing all unused constants can cause a 20% LTO compile-time
slowdown for a large application. So this commit releases unused ConstantArrays
only.

rdar://19040716. It reduces memory footprint from 20+G to 6+G.

llvm-svn: 226592
2015-01-20 19:24:59 +00:00
Rafael Espindola d0b23bef6f Use the DiagnosticHandler to print diagnostics when reading bitcode.
The bitcode reading interface used std::error_code to report an error to the
callers and it is the callers job to print diagnostics.

This is not ideal for error handling or diagnostic reporting:

* For error handling, all that the callers care about is 3 possibilities:
  * It worked
  * The bitcode file is corrupted/invalid.
  * The file is not bitcode at all.

* For diagnostic, it is user friendly to include far more information
  about the invalid case so the user can find out what is wrong with the
  bitcode file. This comes up, for example, when a developer introduces a
  bug while extending the format.

The compromise we had was to have a lot of error codes.

With this patch we use the DiagnosticHandler to communicate with the
human and std::error_code to communicate with the caller.

This allows us to have far fewer error codes and adds the infrastructure to
print better diagnostics. This is so because the diagnostics are printed when
he issue is found. The code that detected the problem in alive in the stack and
can pass down as much context as needed. As an example the patch updates
test/Bitcode/invalid.ll.

Using a DiagnosticHandler also moves the fatal/non-fatal error decision to the
caller. A simple one like llvm-dis can just use fatal errors. The gold plugin
needs a bit more complex treatment because of being passed non-bitcode files. An
hypothetical interactive tool would make all bitcode errors non-fatal.

llvm-svn: 225562
2015-01-10 00:07:30 +00:00
Duncan P. N. Exon Smith df55d8ba83 Linker: Don't use MDNode::replaceOperandWith()
`MDNode::replaceOperandWith()` changes all instances of metadata.  Stop
using it when linking module flags, since (due to uniquing) the flag
values could be used by other metadata.

Instead, use new API `NamedMDNode::setOperand()` to update the reference
directly.

llvm-svn: 225397
2015-01-07 21:32:27 +00:00
Rafael Espindola c6c58d5e71 Finish removing DestroySource.
Fixes pr21901.

llvm-svn: 224782
2014-12-23 19:16:45 +00:00
Duncan P. N. Exon Smith 46d7af5729 Rename MapValue(Metadata*) to MapMetadata()
Instead of reusing the name `MapValue()` when mapping `Metadata`, use
`MapMetadata()`.  The old name doesn't make much sense after the
`Metadata`/`Value` split.

llvm-svn: 224566
2014-12-19 06:06:18 +00:00
Duncan P. N. Exon Smith fda0cee7c6 Reapply "Linker: Drop superseded subprograms"
This reverts commit r224416, reapplying r224389.  The buildbots hadn't
recovered after my revert, waiting until David reverted a couple of his
commits.  It looks like it was just bad timing (where we were both
modifying code related to the same assertion).  Trying again...

Here's the original text:

    When a function gets replaced by `ModuleLinker`, drop superseded
    subprograms.  This ensures that the "first" subprogram pointing at a
    function is the same one that `!dbg` references point at.

    This is a stop-gap fix for PR21910.  Notably, this fixes Release+Asserts
    bootstraps that are currently asserting out in
    `LexicalScopes::initialize()` due to the explicit instantiations in
    `lib/IR/Dominators.cpp` eventually getting replaced by -argpromotion.

llvm-svn: 224487
2014-12-18 01:05:33 +00:00
Duncan P. N. Exon Smith 92731d26bc Revert "Linker: Drop superseded subprograms"
This reverts commit r224389.  Based on feedback from the bots, the
assertion seems to be going off *more* often, not less (previously I was
just seeing it in an internal bootstrap, now it's happening in public
builds too).

http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto_build/936/
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/5325

Reverting in order to investigate.

llvm-svn: 224416
2014-12-17 07:27:31 +00:00
Duncan P. N. Exon Smith 8759026893 Linker: Drop superseded subprograms
When a function gets replaced by `ModuleLinker`, drop superseded
subprograms.  This ensures that the "first" subprogram pointing at a
function is the same one that `!dbg` references point at.

This is a stop-gap fix for PR21910.  Notably, this fixes Release+Asserts
bootstraps that are currently asserting out in
`LexicalScopes::initialize()` due to the explicit instantiations in
`lib/IR/Dominators.cpp` eventually getting replaced by -argpromotion.

llvm-svn: 224389
2014-12-16 23:23:41 +00:00
Rafael Espindola 9573a9cf9d Make the assert a bit stronger.
We should get no declarations in here.

llvm-svn: 224382
2014-12-16 22:29:43 +00:00
Michael Ilseman 8210281d13 Sink the isa into the assert
llvm-svn: 224291
2014-12-15 23:41:21 +00:00
Michael Ilseman 00a6087f6b Clean up warning about unused variable
llvm-svn: 224281
2014-12-15 21:47:09 +00:00
Michael Ilseman 1c38396db7 Revert of r223763, in spirit.
r223763 was made to work around a temporary issue where a user of the
JIT was passing down a declaration (incorrectly). This shouldn't
occur, so assert rather than silently continue.

llvm-svn: 224277
2014-12-15 21:36:29 +00:00
Duncan P. N. Exon Smith 5bf8fef580 IR: Split Metadata from Value
Split `Metadata` away from the `Value` class hierarchy, as part of
PR21532.  Assembly and bitcode changes are in the wings, but this is the
bulk of the change for the IR C++ API.

I have a follow-up patch prepared for `clang`.  If this breaks other
sub-projects, I apologize in advance :(.  Help me compile it on Darwin
I'll try to fix it.  FWIW, the errors should be easy to fix, so it may
be simpler to just fix it yourself.

This breaks the build for all metadata-related code that's out-of-tree.
Rest assured the transition is mechanical and the compiler should catch
almost all of the problems.

Here's a quick guide for updating your code:

  - `Metadata` is the root of a class hierarchy with three main classes:
    `MDNode`, `MDString`, and `ValueAsMetadata`.  It is distinct from
    the `Value` class hierarchy.  It is typeless -- i.e., instances do
    *not* have a `Type`.

  - `MDNode`'s operands are all `Metadata *` (instead of `Value *`).

  - `TrackingVH<MDNode>` and `WeakVH` referring to metadata can be
    replaced with `TrackingMDNodeRef` and `TrackingMDRef`, respectively.

    If you're referring solely to resolved `MDNode`s -- post graph
    construction -- just use `MDNode*`.

  - `MDNode` (and the rest of `Metadata`) have only limited support for
    `replaceAllUsesWith()`.

    As long as an `MDNode` is pointing at a forward declaration -- the
    result of `MDNode::getTemporary()` -- it maintains a side map of its
    uses and can RAUW itself.  Once the forward declarations are fully
    resolved RAUW support is dropped on the ground.  This means that
    uniquing collisions on changing operands cause nodes to become
    "distinct".  (This already happened fairly commonly, whenever an
    operand went to null.)

    If you're constructing complex (non self-reference) `MDNode` cycles,
    you need to call `MDNode::resolveCycles()` on each node (or on a
    top-level node that somehow references all of the nodes).  Also,
    don't do that.  Metadata cycles (and the RAUW machinery needed to
    construct them) are expensive.

  - An `MDNode` can only refer to a `Constant` through a bridge called
    `ConstantAsMetadata` (one of the subclasses of `ValueAsMetadata`).

    As a side effect, accessing an operand of an `MDNode` that is known
    to be, e.g., `ConstantInt`, takes three steps: first, cast from
    `Metadata` to `ConstantAsMetadata`; second, extract the `Constant`;
    third, cast down to `ConstantInt`.

    The eventual goal is to introduce `MDInt`/`MDFloat`/etc. and have
    metadata schema owners transition away from using `Constant`s when
    the type isn't important (and they don't care about referring to
    `GlobalValue`s).

    In the meantime, I've added transitional API to the `mdconst`
    namespace that matches semantics with the old code, in order to
    avoid adding the error-prone three-step equivalent to every call
    site.  If your old code was:

        MDNode *N = foo();
        bar(isa             <ConstantInt>(N->getOperand(0)));
        baz(cast            <ConstantInt>(N->getOperand(1)));
        bak(cast_or_null    <ConstantInt>(N->getOperand(2)));
        bat(dyn_cast        <ConstantInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<ConstantInt>(N->getOperand(4)));

    you can trivially match its semantics with:

        MDNode *N = foo();
        bar(mdconst::hasa               <ConstantInt>(N->getOperand(0)));
        baz(mdconst::extract            <ConstantInt>(N->getOperand(1)));
        bak(mdconst::extract_or_null    <ConstantInt>(N->getOperand(2)));
        bat(mdconst::dyn_extract        <ConstantInt>(N->getOperand(3)));
        bay(mdconst::dyn_extract_or_null<ConstantInt>(N->getOperand(4)));

    and when you transition your metadata schema to `MDInt`:

        MDNode *N = foo();
        bar(isa             <MDInt>(N->getOperand(0)));
        baz(cast            <MDInt>(N->getOperand(1)));
        bak(cast_or_null    <MDInt>(N->getOperand(2)));
        bat(dyn_cast        <MDInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<MDInt>(N->getOperand(4)));

  - A `CallInst` -- specifically, intrinsic instructions -- can refer to
    metadata through a bridge called `MetadataAsValue`.  This is a
    subclass of `Value` where `getType()->isMetadataTy()`.

    `MetadataAsValue` is the *only* class that can legally refer to a
    `LocalAsMetadata`, which is a bridged form of non-`Constant` values
    like `Argument` and `Instruction`.  It can also refer to any other
    `Metadata` subclass.

(I'll break all your testcases in a follow-up commit, when I propagate
this change to assembly.)

llvm-svn: 223802
2014-12-09 18:38:53 +00:00
Michael Ilseman 2770c2d6d4 Skip declarations in the case of functions.
This is a revert of r223521 in spirit, if not in content. I am not
sure why declarations ended up in LazilyLinkGlobalValues in the first
place; that will take some more investigation.

llvm-svn: 223763
2014-12-09 08:20:06 +00:00
Rafael Espindola ef23711eee Lazily link GlobalVariables and GlobalAliases.
We were already lazily linking functions, but all GlobalValues can be treated
uniformly for this.

The test updates are to ensure that a given GlobalValue is still linked in.

This fixes pr21494.

llvm-svn: 223681
2014-12-08 18:45:16 +00:00
Rafael Espindola beadd56a7d Don't crash when the key of a comdat is lazily linked.
llvm-svn: 223673
2014-12-08 18:05:48 +00:00
Rafael Espindola 3519da82b8 Move the ValueMap lookup inside linkFunctionBody. NFC.
llvm-svn: 223659
2014-12-08 14:25:26 +00:00
Rafael Espindola a314d1aca4 Use range loops. NFC.
llvm-svn: 223658
2014-12-08 14:20:10 +00:00
Rafael Espindola 21ec84eb81 Use range loops. NFC.
llvm-svn: 223657
2014-12-08 14:05:33 +00:00
Rafael Espindola 869d1ce811 Fix linking of prologue data.
It would crash when the function was lazy linked.

llvm-svn: 223656
2014-12-08 13:44:38 +00:00
Rafael Espindola f97d0cbe58 Simple style fixes.
* Use a range loop.
* Move simple continue checks earlier.
* clang-format.

llvm-svn: 223654
2014-12-08 13:35:09 +00:00
Rafael Espindola 40d7ebed8a Move materialize/Dematerialize calls to linkFunctionBody. NFC.
Just less code duplication.

llvm-svn: 223653
2014-12-08 13:29:33 +00:00
Benjamin Kramer 3280a5d9f5 Turn some DenseMaps that are only used for set operations into DenseSets.
DenseSet has better memory efficiency now.

llvm-svn: 223589
2014-12-06 19:22:54 +00:00
Rafael Espindola de567e022b Remove dead code. We are only lazy about functions with bodies.
llvm-svn: 223521
2014-12-05 21:36:06 +00:00
Rafael Espindola 28a2451b35 Simplify the loop linking function bodies. NFC.
llvm-svn: 223512
2014-12-05 21:04:36 +00:00
Rafael Espindola 2bd5b9f558 Remove unused arguments. NFC.
llvm-svn: 223503
2014-12-05 19:35:07 +00:00
Rafael Espindola 26c2951117 Refactor duplicated code. NFC.
llvm-svn: 223486
2014-12-05 17:53:15 +00:00
Rafael Espindola 879aeb776c Small cleanup on how we clear constant variables. NFC.
llvm-svn: 223474
2014-12-05 16:05:19 +00:00
Rafael Espindola ad9d0ca878 Use an early return. NFC.
llvm-svn: 223470
2014-12-05 15:42:30 +00:00
Rafael Espindola 3124ed4b23 linkGlobalVariableProto never returns null. Simplify the caller. NFC.
llvm-svn: 223424
2014-12-05 00:30:47 +00:00
Rafael Espindola 439835a6fe Move merging of alignment to a central location. NFC.
llvm-svn: 223418
2014-12-05 00:09:02 +00:00
Rafael Espindola 31ad468d03 Split the set of identified struct types into opaque and non-opaque ones.
The non-opaque part can be structurally uniqued. To keep this to just
a hash lookup, we don't try to unique cyclic types.

Also change the type mapping algorithm to be optimistic about a type
not being recursive and only create a new type when proven to be wrong.
This is not as strong as trying to speculate that we can keep the source
type, but is simpler (no speculation to revert) and more powerfull
than what we had before (we don't copy non-recursive types at least).

I initially wrote this to try to replace the name based type merging.
It is not strong enough to replace it, but is is a useful addition.

With this patch the number of named struct types is a clang lto bootstrap goes
from 49674 to 15986.

llvm-svn: 223278
2014-12-03 22:36:37 +00:00
Rafael Espindola 2fa1e43a22 Ask the module for its the identified types.
When lazy reading a module, the types used in a function will not be visible to
a TypeFinder until the body is read.

This patch fixes that by asking the module for its identified struct types.
If a materializer is present, the module asks it. If not, it uses a TypeFinder.

This fixes pr21374.

I will be the first to say that this is ugly, but it was the best I could find.

Some of the options I looked at:

* Asking the LLVMContext. This could be made to work for gold, but not currently
  for ld64. ld64 will load multiple modules into a single context before merging
  them. This causes us to see types from future merges. Unfortunately,
  MappedTypes is not just a cache when it comes to opaque types. Once the
  mapping has been made, we have to remember it for as long as the key may
  be used. This would mean moving MappedTypes to the Linker class and having
  to drop the Linker::LinkModules static methods, which are visible from C.

* Adding an option to ignore function bodies in the TypeFinder. This would
  fix the PR by picking the worst result. It would work, but unfortunately
  we are currently quite dependent on the upfront type merging. I will
  try to reduce our dependency, but it is not clear that we will be able
  to get rid of it for now.

The only clean solution I could think of is making the Module own the types.
This would have other advantages, but it is a much bigger change. I will
propose it, but it is nice to have this fixed while that is discussed.

With the gold plugin, this patch takes the number of types in the LTO clang
binary from 52817 to 49669.

llvm-svn: 223215
2014-12-03 07:18:23 +00:00
Peter Collingbourne 51d2de7b9e Prologue support
Patch by Ben Gamari!

This redefines the `prefix` attribute introduced previously and
introduces a `prologue` attribute.  There are a two primary usecases
that these attributes aim to serve,

  1. Function prologue sigils

  2. Function hot-patching: Enable the user to insert `nop` operations
     at the beginning of the function which can later be safely replaced
     with a call to some instrumentation facility

  3. Runtime metadata: Allow a compiler to insert data for use by the
     runtime during execution. GHC is one example of a compiler that
     needs this functionality for its tables-next-to-code functionality.

Previously `prefix` served cases (1) and (2) quite well by allowing the user
to introduce arbitrary data at the entrypoint but before the function
body. Case (3), however, was poorly handled by this approach as it
required that prefix data was valid executable code.

Here we redefine the notion of prefix data to instead be data which
occurs immediately before the function entrypoint (i.e. the symbol
address). Since prefix data now occurs before the function entrypoint,
there is no need for the data to be valid code.

The previous notion of prefix data now goes under the name "prologue
data" to emphasize its duality with the function epilogue.

The intention here is to handle cases (1) and (2) with prologue data and
case (3) with prefix data.

References
----------

This idea arose out of discussions[1] with Reid Kleckner in response to a
proposal to introduce the notion of symbol offsets to enable handling of
case (3).

[1] http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-May/073235.html

Test Plan: testsuite

Differential Revision: http://reviews.llvm.org/D6454

llvm-svn: 223189
2014-12-03 02:08:38 +00:00
Rafael Espindola 973b3612e4 Use a continue to reduce indentation and clang-format. NFC.
llvm-svn: 223067
2014-12-01 19:17:46 +00:00
Rafael Espindola 4d4c938770 Use a range loop. NFC.
llvm-svn: 223066
2014-12-01 19:08:07 +00:00
Rafael Espindola dd42b533e9 Drop SrcStructTypesSet. It is redundant.
At the only point in the code it is used, we haven't added any of the src types
to DstStructTypesSet yet.

llvm-svn: 223057
2014-12-01 18:42:18 +00:00
Rafael Espindola a4e85e3db0 Partial revert of r222986.
The explicit set of destination types is not fully redundant when lazy loading
since the TypeFinder will not find types used only in function bodies.

This keeps the logic to drop the name of mapped types since it still helps
with avoiding further renaming.

llvm-svn: 223043
2014-12-01 16:32:20 +00:00
Rafael Espindola 04a74af734 Change how we keep track of which types are in the dest module.
Instead of keeping an explicit set, just drop the names of types we choose
to map to some other type.

This has the advantage that the name of the unused will not cause the context
to rename types on module read.

llvm-svn: 222986
2014-12-01 04:15:59 +00:00
Rafael Espindola a96f235c15 Add back r222727 with a fix.
The original patch would fail when:

* A dst opaque type (%A) is matched with a src type (%A).
* A src opaque (%E) type is then speculatively matched with %A and the
  speculation fails afterward.
* When rolling back the speculation we would cancel the source %A to dest
  %A mapping.

The fix is to keep an explicit list of which resolutions are speculative.

Original message:

Fix overly aggressive type merging.

If we find out that two types are *not* isomorphic, we learn nothing about
opaque sub types in both the source and destination.

llvm-svn: 222923
2014-11-28 16:41:24 +00:00
Rafael Espindola 3d0974105a Add an assert and use a range loop. NFC.
llvm-svn: 222922
2014-11-28 16:26:14 +00:00
Duncan P. N. Exon Smith c586eaa1f1 Revert "Fix overly aggressive type merging."
This reverts commit r222727, which causes LTO bootstrap failures.

Last passing @ r222698:
http://lab.llvm.org:8080/green/job/clang-Rlto_master_build/532/

First failing @ r222843:
http://lab.llvm.org:8080/green/job/clang-Rlto_master_build/533/

Internal bootstraps pointed at a much narrower range: r222725 is
passing, and r222731 is failing.

LTO crashes while handling libclang.dylib:
http://lab.llvm.org:8080/green/job/clang-Rlto_master_build/533/consoleFull#-158682280549ba4694-19c4-4d7e-bec5-911270d8a58c

    GEP is not of right type for indices!
      %InfoObj.i.i = getelementptr inbounds %"class.llvm::OnDiskIterableChainedHashTable"* %.lcssa, i64 0, i32 0, i32 4, !dbg !123627
     %"class.clang::serialization::reader::ASTIdentifierLookupTrait" = type { %"class.clang::ASTReader.31859"*, %"class.clang::serialization::ModuleFile.31870"*, %"class.clang::IdentifierInfo"* }LLVM ERROR: Broken function found, compilation aborted!
    clang: error: linker command failed with exit code 1 (use -v to see invocation)

Looks like the new algorithm doesn't merge types aggressively enough.

llvm-svn: 222895
2014-11-27 17:01:10 +00:00
Rafael Espindola c81c3f554c Set the body of a new struct as soon as it is created.
This changes the order in which different types are passed to get, but
one order is not inherently better than the other.

The main motivation is that this simplifies linkDefinedTypeBodies now that
it is only linking "real" opaque types. It is also means that we only have to
call it once and that we don't need getImpl.

A small change in behavior is that we don't copy type names when resolving
opaque types. This is an improvement IMHO, but it can be added back if
desired. A test is included with the new behavior.

llvm-svn: 222764
2014-11-25 15:33:40 +00:00
Rafael Espindola 290e2cc520 Misc style fixes. NFC.
This just reduces the noise in the next patch.

llvm-svn: 222761
2014-11-25 14:35:53 +00:00
Rafael Espindola 5e7f98071a Remove a bit of duplicated code.
Exactly the same checks are present in areTypesIsomorphic.

This might have been a premature performance optimization. I cannot reproduce
any slowdown with this patch.

llvm-svn: 222758
2014-11-25 13:19:46 +00:00
Rafael Espindola 8f14471e81 Use a range loop. NFC.
llvm-svn: 222730
2014-11-25 06:16:27 +00:00
Rafael Espindola c84f608b08 Style fix: don't indent inside a namemespace.
llvm-svn: 222729
2014-11-25 06:11:24 +00:00
Rafael Espindola f010311166 Remove a nested anonymous namespace.
llvm-svn: 222728
2014-11-25 06:07:51 +00:00
Rafael Espindola 86911440c2 Fix overly aggressive type merging.
If we find out that two types are *not* isomorphic, we learn nothing about
opaque sub types in both the source and destination.

llvm-svn: 222727
2014-11-25 05:59:24 +00:00
Rafael Espindola e96d7eb8bd Link the type of aliases.
They are not more or less "well typed" than GlobalVariables.

llvm-svn: 222725
2014-11-25 04:43:59 +00:00
Rafael Espindola d2a13a2ec6 Don't repeat name in comment or duplicate comment. NFC.
llvm-svn: 222724
2014-11-25 04:28:31 +00:00
Rafael Espindola c8a476ee11 Use range loops. NFC.
llvm-svn: 222723
2014-11-25 04:26:19 +00:00
David Blaikie 70573dcd9f Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

llvm-svn: 222334
2014-11-19 07:49:26 +00:00
David Blaikie 5106ce7897 Remove StringMap::GetOrCreateValue in favor of StringMap::insert
Having two ways to do this doesn't seem terribly helpful and
consistently using the insert version (which we already has) seems like
it'll make the code easier to understand to anyone working with standard
data structures. (I also updated many references to the Entry's
key and value to use first() and second instead of getKey{Data,Length,}
and get/setValue - for similar consistency)

Also removes the GetOrCreateValue functions so there's less surface area
to StringMap to fix/improve/change/accommodate move semantics, etc.

llvm-svn: 222319
2014-11-19 05:49:42 +00:00
Rafael Espindola 5cb9c82a5d Factor common code it Linker::init.
The TypeFinder was not being used in one of the constructors.

llvm-svn: 222172
2014-11-17 20:51:01 +00:00
Duncan P. N. Exon Smith de36e8040f Revert "IR: MDNode => Value"
Instead, we're going to separate metadata from the Value hierarchy.  See
PR21532.

This reverts commit r221375.
This reverts commit r221373.
This reverts commit r221359.
This reverts commit r221167.
This reverts commit r221027.
This reverts commit r221024.
This reverts commit r221023.
This reverts commit r220995.
This reverts commit r220994.

llvm-svn: 221711
2014-11-11 21:30:22 +00:00
Duncan P. N. Exon Smith c5754a65e6 IR: MDNode => Value: NamedMDNode::getOperator()
Change `NamedMDNode::getOperator()` from returning `MDNode *` to
returning `Value *`.  To reduce boilerplate at some call sites, add a
`getOperatorAsMDNode()` for named metadata that's expected to only
return `MDNode` -- for now, that's everything, but debug node named
metadata (such as llvm.dbg.cu and llvm.dbg.sp) will soon change.  This
is part of PR21433.

Note that there's a follow-up patch to clang for the API change.

llvm-svn: 221375
2014-11-05 18:16:03 +00:00
Rafael Espindola 778fcc770b Revert r221096 bringing back r221014 with a fix.
The issue was that linkAppendingVarProto does the full linking job, including
deleting the old dst variable. The fix is just to call it and return early
if we have a GV with appending linkage.

original message:

    Refactor duplicated code in liking GlobalValues.

    There is quiet a bit of logic that is common to any GlobalValue but was
    duplicated for Functions, GlobalVariables and GlobalAliases.

    While at it, merge visibility even when comdats are used, fixing pr21415.

llvm-svn: 221098
2014-11-02 13:28:57 +00:00
Chandler Carruth fd38af2d13 Revert r221014: "Refactor duplicated code in liking GlobalValues."
This commit introduces heap-use-after-free detected by ASan. Here is the output
for one of several tests that detect it:

******************** TEST 'LLVM :: Linker/AppendingLinkage.ll' FAILED ********************
Command Output (stderr):
--
=================================================================
==2122==ERROR: AddressSanitizer: heap-use-after-free on address 0x60c00000b9c8 at pc 0x0000005d05d1 bp 0x7fff64ed27c0 sp 0x7fff64ed27b8
READ of size 4 at 0x60c00000b9c8 thread T0
    #0 0x5d05d0 in llvm::GlobalValue::setUnnamedAddr(bool) /usr/local/google/home/chandlerc/src/llvm/build/../include/llvm/IR/GlobalValue.h:115:35
    #1 0x69fff1 in (anonymous namespace)::ModuleLinker::linkGlobalValueProto(llvm::GlobalValue*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1041:5
    #2 0x697229 in (anonymous namespace)::ModuleLinker::run() /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1485:9
    #3 0x696542 in llvm::Linker::linkInModule(llvm::Module*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1621:10
    #4 0x4a2db7 in main /usr/local/google/home/chandlerc/src/llvm/build/../tools/llvm-link/llvm-link.cpp:116:9
    #5 0x7f4ae61e5ec4 in __libc_start_main /build/buildd/eglibc-2.19/csu/libc-start.c:287
    #6 0x41eb71 in _start (/usr/local/google/home/chandlerc/src/llvm/build/bin/llvm-link+0x41eb71)

0x60c00000b9c8 is located 72 bytes inside of 128-byte region [0x60c00000b980,0x60c00000ba00)
freed by thread T0 here:
    #0 0x4a1e6b in operator delete(void*) /usr/local/google/home/chandlerc/src/llvm/opt-build/../projects/compiler-rt/lib/asan/asan_new_delete.cc:94:3
    #1 0x5d1a7a in llvm::iplist<llvm::GlobalVariable, llvm::ilist_traits<llvm::GlobalVariable> >::erase(llvm::ilist_iterator<llvm::GlobalVariable>) /usr/local/google/home/chandlerc/src/llvm/build/../inclu
de/llvm/ADT/ilist.h:466:5
    #2 0x5d1980 in llvm::GlobalVariable::eraseFromParent() /usr/local/google/home/chandlerc/src/llvm/build/../lib/IR/Globals.cpp:204:3
    #3 0x6a8a4d in (anonymous namespace)::ModuleLinker::linkAppendingVarProto(llvm::GlobalVariable*, llvm::GlobalVariable const*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.
cpp:980:3
    #4 0x6a7403 in (anonymous namespace)::ModuleLinker::linkGlobalVariableProto(llvm::GlobalVariable const*, llvm::GlobalValue*, bool) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkMod
ules.cpp:1074:11
    #5 0x69ff4e in (anonymous namespace)::ModuleLinker::linkGlobalValueProto(llvm::GlobalValue*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1028:13
    #6 0x697229 in (anonymous namespace)::ModuleLinker::run() /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1485:9
    #7 0x696542 in llvm::Linker::linkInModule(llvm::Module*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1621:10
    #8 0x4a2db7 in main /usr/local/google/home/chandlerc/src/llvm/build/../tools/llvm-link/llvm-link.cpp:116:9
    #9 0x7f4ae61e5ec4 in __libc_start_main /build/buildd/eglibc-2.19/csu/libc-start.c:287

previously allocated by thread T0 here:
    #0 0x4a192b in operator new(unsigned long) /usr/local/google/home/chandlerc/src/llvm/opt-build/../projects/compiler-rt/lib/asan/asan_new_delete.cc:62:35
    #1 0x61d85c in llvm::User::operator new(unsigned long, unsigned int) /usr/local/google/home/chandlerc/src/llvm/build/../lib/IR/User.cpp:57:19
    #2 0x6a7525 in (anonymous namespace)::ModuleLinker::linkGlobalVariableProto(llvm::GlobalVariable const*, llvm::GlobalValue*, bool) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkMod
ules.cpp:1100:3
    #3 0x69ff4e in (anonymous namespace)::ModuleLinker::linkGlobalValueProto(llvm::GlobalValue*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1028:13
    #4 0x697229 in (anonymous namespace)::ModuleLinker::run() /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1485:9
    #5 0x696542 in llvm::Linker::linkInModule(llvm::Module*) /usr/local/google/home/chandlerc/src/llvm/build/../lib/Linker/LinkModules.cpp:1621:10
    #6 0x4a2db7 in main /usr/local/google/home/chandlerc/src/llvm/build/../tools/llvm-link/llvm-link.cpp:116:9
    #7 0x7f4ae61e5ec4 in __libc_start_main /build/buildd/eglibc-2.19/csu/libc-start.c:287

SUMMARY: AddressSanitizer: heap-use-after-free /usr/local/google/home/chandlerc/src/llvm/build/../include/llvm/IR/GlobalValue.h:115 llvm::GlobalValue::setUnnamedAddr(bool)
Shadow bytes around the buggy address:
  0x0c187fff96e0: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
  0x0c187fff96f0: 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa fa
  0x0c187fff9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fa
  0x0c187fff9710: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
  0x0c187fff9720: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa
=>0x0c187fff9730: fd fd fd fd fd fd fd fd fd[fd]fd fd fd fd fd fd
  0x0c187fff9740: fa fa fa fa fa fa fa fa fd fd fd fd fd fd fd fd
  0x0c187fff9750: fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa fa
  0x0c187fff9760: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c187fff9770: fa fa fa fa fa fa fa fa fd fd fd fd fd fd fd fd
  0x0c187fff9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Heap right redzone:      fb
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack partial redzone:   f4
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  ASan internal:           fe
==2122==ABORTING

llvm-svn: 221096
2014-11-02 09:10:31 +00:00
Rafael Espindola 246c4fb5d9 Remove redundant calls to isMaterializable.
This removes calls to isMaterializable in the following cases:

* It was redundant with a call to isDeclaration now that isDeclaration returns
  the correct answer for materializable functions.
* It was followed by a call to Materialize. Just call Materialize and check EC.

llvm-svn: 221050
2014-11-01 16:46:18 +00:00
Rafael Espindola 4e27567a12 Refactor duplicated code in liking GlobalValues.
There is quiet a bit of logic that is common to any GlobalValue but was
duplicated for Functions, GlobalVariables and GlobalAliases.

While at it, merge visibility even when comdats are used, fixing pr21415.

llvm-svn: 221014
2014-10-31 23:10:07 +00:00
Rafael Espindola 3e8bc6a8c3 Mark a few variables const. NFC.
llvm-svn: 220964
2014-10-31 16:08:17 +00:00
Rafael Espindola 0ae225b6b5 Move definition closer to use. NFC.
llvm-svn: 220949
2014-10-31 04:46:38 +00:00
Rafael Espindola d1e64b1e93 Fix the merging of the constantness of declarations.
The langref says:

LLVM explicitly allows declarations of global variables to be marked
constant, even if the final definition of the global is not. This
capability can be used to enable slightly better optimization of the
program, but requires the language definition to guarantee that
optimizations based on the ‘constantness’ are valid for the
translation units that do not include the definition.

Given that definition, when merging two declarations, we have to drop
constantness if of of them is not marked contant, since the Module
without the constant marker might not have the necessary guarantees.

llvm-svn: 220927
2014-10-30 20:50:23 +00:00
Rafael Espindola 9f8eff31db Remove the PreserveSource linker mode.
I noticed that it was untested, and forcing it on caused some tests to fail:

    LLVM :: Linker/metadata-a.ll
    LLVM :: Linker/prefixdata.ll
    LLVM :: Linker/type-unique-odr-a.ll
    LLVM :: Linker/type-unique-simple-a.ll
    LLVM :: Linker/type-unique-simple2-a.ll
    LLVM :: Linker/type-unique-simple2.ll
    LLVM :: Linker/type-unique-type-array-a.ll
    LLVM :: Linker/unnamed-addr1-a.ll
    LLVM :: Linker/visibility1.ll

If it is to be resurrected, it has to be fixed and we should probably have a
-preserve-source command line option in llvm-mc and run tests with and without
it.

llvm-svn: 220741
2014-10-28 00:24:16 +00:00
Rafael Espindola 4160f5d3ac Make it easier to pass a custom diagnostic handler to the IR linker.
llvm-svn: 220732
2014-10-27 23:02:10 +00:00
Rafael Espindola 18c89411b8 LinkModules.cpp: don't repeat names in comments.
llvm-svn: 220662
2014-10-27 02:35:46 +00:00
Rafael Espindola 98ab63ce98 Allow the C API users to keep relying on the OutMessages parameter.
Should fix the Ocaml tests.

llvm-svn: 220611
2014-10-25 04:31:08 +00:00
Rafael Espindola d12b4a334b Update the error handling of lib/Linker.
Instead of passing a std::string&, use the new diagnostic infrastructure.

llvm-svn: 220608
2014-10-25 04:06:10 +00:00
Rafael Espindola 5a52e6dc9e Modernize the error handling of the Materialize function.
llvm-svn: 220600
2014-10-24 22:50:48 +00:00
Rafael Espindola d4bcefc7d9 Don't ever call materializeAllPermanently during LTO.
To do this, change the representation of lazy loaded functions.

The previous representation cannot differentiate between a function whose body
has been removed and one whose body hasn't been read from the .bc file. That
means that in order to drop a function, the entire body had to be read.

llvm-svn: 220580
2014-10-24 18:13:04 +00:00
Rafael Espindola fe3842cda7 Merge alignment of common GlobalValue.
Fixes pr20882.

llvm-svn: 217455
2014-09-09 17:48:18 +00:00
Rafael Espindola 0910605af6 When merging two common GlobalValues, keep the largest.
llvm-svn: 217451
2014-09-09 15:59:12 +00:00
Rafael Espindola dbb0bd1a42 Move some logic to ModuleLinker::shouldLinkFromSource. NFC.
llvm-svn: 217449
2014-09-09 15:21:00 +00:00
Rafael Espindola c83c8d4e74 Fix a use of an undefined value (the linkage).
llvm-svn: 217445
2014-09-09 14:52:27 +00:00
Rafael Espindola 7fc29546f9 Prefer common over weak linkage when linking.
This matches the behavior of ELF linkers.

llvm-svn: 217443
2014-09-09 14:27:09 +00:00
Rafael Espindola 83a7ddbc9a Simplify ModuleLinker::getLinkageResult. NFC.
llvm-svn: 217441
2014-09-09 14:07:40 +00:00
Rafael Espindola d31dc048ca Fix pr20078.
When linking llvm.global_ctors with the optional third element we have to handle
it specially and only copy the elements whose keys were also copied.

llvm-svn: 217281
2014-09-05 21:27:52 +00:00
Rafael Espindola 3931c28b03 Set comdats when lazily linking functions.
We were setting the comdat when functions were copied in the initial pass, but
not when they were linked only when we found out that they are needed.

llvm-svn: 215765
2014-08-15 20:17:08 +00:00
Duncan P. N. Exon Smith 09d84addb7 Don't upgrade global constructors when reading bitcode
An optional third field was added to `llvm.global_ctors` (and
`llvm.global_dtors`) in r209015.  Most of the code has been changed to
deal with both versions of the variables.  Users of the C API might
create either version, the helper functions in LLVM create the two-field
version, and clang now creates the three-field version.

However, the BitcodeReader was changed to always upgrade to the
three-field version.  This created an unnecessary inconsistency in the
IR before/after serializing to bitcode.

This commit resolves the inconsistency by making the third field truly
optional (and not upgrading in the bitcode reader).  Since `llvm-link`
was relying on this upgrade code, rather than deleting it I've moved it
into `ModuleLinker`, where it upgrades these arrays as necessary to
resolve inconsistencies between modules.

The ideal resolution would be to remove the 2-field version and make the
third field required.  I filed PR20506 to track that.

I changed `test/Bitcode/upgrade-global-ctors.ll` to a negative test and
duplicated the `llvm-link` check in `test/Linker/global_ctors.ll` to
check both upgrade directions.

Since I came across this as part of PR5680 (serializing use-list order),
I've also added the missing `verify-uselistorder` RUN line to
`test/Bitcode/metadata-2.ll`.

llvm-svn: 215457
2014-08-12 16:46:37 +00:00
Justin Bogner c0087f3611 IR: Print a newline when dumping Types
Type::dump() doesn't print a newline, which makes for a poor
experience in a debugger. This looks like it was an ommission
considering Value::dump() two lines above, so I've changed Type to add
a newline as well.

Of the two in-tree callers, one added a newline anyway, and I've
updated the other one to use Type::print instead.

llvm-svn: 215421
2014-08-12 03:24:59 +00:00
Rafael Espindola b16196a3e0 Fix use of uninitialized variable.
Fixes linking bitcode files that use the new style comdats for constructors
with ones that don't.

llvm-svn: 215364
2014-08-11 17:07:34 +00:00
Rafael Espindola 2ef3f299d5 Use an early return. NFC.
llvm-svn: 215363
2014-08-11 16:55:42 +00:00
David Majnemer 82d6ff6b5b Include <tuple> to make buildbots happy
llvm-svn: 211949
2014-06-27 18:38:12 +00:00
David Majnemer dad0a645a7 IR: Add COMDATs to the IR
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.

COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.

This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.

Differential Revision: http://reviews.llvm.org/D4178

llvm-svn: 211920
2014-06-27 18:19:56 +00:00
Craig Topper 2a30d7889f Replace some assert(0)'s with llvm_unreachable.
llvm-svn: 211141
2014-06-18 05:05:13 +00:00
Rafael Espindola 42a4c9f9e0 Allow aliases to be unnamed_addr.
Alias with unnamed_addr were in a strange state. It is stored in GlobalValue,
the language reference talks about "unnamed_addr aliases" but the verifier
was rejecting them.

It seems natural to allow unnamed_addr in aliases:

* It is a property of how it is accessed, not of the data itself.
* It is perfectly possible to write code that depends on the address
of an alias.

This patch then makes unname_addr legal for aliases. One side effect is that
the syntax changes for a corner case: In globals, unnamed_addr is now printed
before the address space.

llvm-svn: 210302
2014-06-06 01:20:28 +00:00
Rafael Espindola 64c1e18033 Allow alias to point to an arbitrary ConstantExpr.
This  patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is
up to MC (or the system assembler) to decide if that expression is valid or not.

This reduces our ability to diagnose invalid uses and how early we can spot
them, but it also lets us do things like

@test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32),
                                 i32 ptrtoint (i32* @bar to i32)) to i32*)

An important implication of this patch is that the notion of aliased global
doesn't exist any more. The alias has to encode the information needed to
access it in its metadata (linkage, visibility, type, etc).

Another consequence to notice is that getSection has to return a "const char *".
It could return a NullTerminatedStringRef if there was such a thing, but when
that was proposed the decision was to just uses "const char*" for that.

llvm-svn: 210062
2014-06-03 02:41:57 +00:00
Rafael Espindola f1bedd3747 Use create methods since msvc doesn't handle delegating constructors.
llvm-svn: 209076
2014-05-17 21:29:57 +00:00
Rafael Espindola 8370565820 Reduce abuse of default values in the GlobalAlias constructor.
This is in preparation for adding an optional offset.

llvm-svn: 209073
2014-05-17 19:57:46 +00:00
Rafael Espindola 6b238633b7 Fix most of PR10367.
This patch changes the design of GlobalAlias so that it doesn't take a
ConstantExpr anymore. It now points directly to a GlobalObject, but its type is
independent of the aliasee type.

To avoid changing all alias related tests in this patches, I kept the common
syntax

@foo = alias i32* @bar

to mean the same as now. The cases that used to use cast now use the more
general syntax

@foo = alias i16, i32* @bar.

Note that GlobalAlias now behaves a bit more like GlobalVariable. We
know that its type is always a pointer, so we omit the '*'.

For the bitcode, a nice surprise is that we were writing both identical types
already, so the format change is minimal. Auto upgrade is handled by looking
through the casts and no new fields are needed for now. New bitcode will
simply have different types for Alias and Aliasee.

One last interesting point in the patch is that replaceAllUsesWith becomes
smart enough to avoid putting a ConstantExpr in the aliasee. This seems better
than checking and updating every caller.

A followup patch will delete getAliasedGlobal now that it is redundant. Another
patch will add support for an explicit offset.

llvm-svn: 209007
2014-05-16 19:35:39 +00:00
Rafael Espindola 4fe0094fd1 Change the GlobalAlias constructor to look a bit more like GlobalVariable.
This is part of the fix for pr10367. A GlobalAlias always has a pointer type,
so just have the constructor build the type.

llvm-svn: 208983
2014-05-16 13:34:04 +00:00
Rafael Espindola 99e05cf163 Split GlobalValue into GlobalValue and GlobalObject.
This allows code to statically accept a Function or a GlobalVariable, but
not an alias. This is already a cleanup by itself IMHO, but the main
reason for it is that it gives a lot more confidence that the refactoring to fix
the design of GlobalAlias is correct. That will be a followup patch.

llvm-svn: 208716
2014-05-13 18:45:48 +00:00
Rafael Espindola ed6dc3730a Delete trailing whitespace.
llvm-svn: 208416
2014-05-09 14:39:25 +00:00
Duncan P. N. Exon Smith b2becfdbae LTO: Assert visibility of local linkage when merging symbols
`ModuleLinker::getLinkageResult()` shouldn't create symbols with local
linkage and non-default visibility -- in fact, symbols with local
linkage shouldn't be merged at all.  Assert to that effect.

llvm-svn: 208262
2014-05-07 22:55:46 +00:00
Rafael Espindola a7d9c69cc8 Be more strict about not calling setAlignment on global aliases.
The fact that GlobalAlias::setAlignment exists at all is a side effect of
how the classes are organized, it should never be used.

llvm-svn: 208094
2014-05-06 14:51:36 +00:00
Craig Topper 2617dccea2 [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.
llvm-svn: 206252
2014-04-15 06:32:26 +00:00
Chandler Carruth 6cc07df4ec [Layering] Sink Linker.h into a Linker subdirectory to make it
consistent with every other sub-library header in LLVM.

llvm-svn: 203065
2014-03-06 03:42:23 +00:00
JF Bastien 026fc5f6ab Improve LinkModules warnings
Provide triple and data layout as well as module names (or empty string) when there's a mismatch.

Differential Revision: http://llvm-reviews.chandlerc.com/D2971

llvm-svn: 203009
2014-03-05 21:26:42 +00:00
Craig Topper 8548299aa8 [C++11] Add 'override' keyword to virtual methods that override their base class.
llvm-svn: 202946
2014-03-05 07:52:44 +00:00
Rafael Espindola ae593f1563 Compare DataLayout by Value, not by pointer.
This fixes spurious warnings in llvm-link about the datalayout not matching.

Thanks to Zalman Stern for reporting the bug!

llvm-svn: 202276
2014-02-26 17:02:08 +00:00
Rafael Espindola f863ee2949 Store a DataLayout in Module.
Now that DataLayout is not a pass, store one in Module.

Since the C API expects to be able to get a char* to the datalayout description,
we have to keep a std::string somewhere. This patch keeps it in Module and also
uses it to represent modules without a DataLayout.

Once DataLayout is mandatory, we should probably move the string to DataLayout
itself since it won't be necessary anymore to represent the special case of a
module without a DataLayout.

llvm-svn: 202190
2014-02-25 20:01:08 +00:00
Eli Bendersky 7da92ed879 Set the SuppressWarnings option on tool level and propagate to the library.
The SuppressWarnings flag, unfortunately, isn't very useful for custom tools
that want to use the LLVM module linker. So I'm changing it to a parameter of
the Linker, and the flag itself moves to the llvm-link tool.

For the time being as SuppressWarnings is pretty much the only "option" it
seems reasonable to propagate it to Linker objects. If we end up with more
options in the future, some sort of "struct collecting options" may be a
better idea.

llvm-svn: 201819
2014-02-20 22:19:24 +00:00
Eli Bendersky e17f37082b Add a -suppress-warnings option to bitcode linking.
llvm-svn: 200927
2014-02-06 18:01:56 +00:00
Bill Wendling 91686d6dee Reapply r194218 with fix:
Move copying of global initializers below the cloning of functions.

The BlockAddress doesn't have access to the correct basic blocks until the
functions have been cloned. This causes the BlockAddress to point to the old
values. Just wait until the functions have been cloned before copying the
initializers.
PR13163

llvm-svn: 199354
2014-01-16 06:29:36 +00:00
Nico Rieck 7157bb765e Decouple dllexport/dllimport from linkage
Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.

Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:

  define available_externally dllimport void @f() {}
  @Var = dllexport global i32 1, align 4

Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.

llvm-svn: 199218
2014-01-14 15:22:47 +00:00
Nico Rieck 9d2e0df049 Revert "Decouple dllexport/dllimport from linkage"
Revert this for now until I fix an issue in Clang with it.

This reverts commit r199204.

llvm-svn: 199207
2014-01-14 12:38:32 +00:00
Nico Rieck e43aaf7967 Decouple dllexport/dllimport from linkage
Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.

Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:

  define available_externally dllimport void @f() {}
  @Var = dllexport global i32 1, align 4

Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.

llvm-svn: 199204
2014-01-14 11:55:03 +00:00
Adrian Prantl a473a2ba19 Revert "Move copying of global initializers below the cloning of functions."
This would cause internal symbols that are only referenced by global initializers to be removed.

This reverts commit 194219.

llvm-svn: 194304
2013-11-09 00:43:18 +00:00
Bill Wendling 8890460431 Move copying of global initializers below the cloning of functions.
The BlockAddress doesn't have access to the correct basic blocks until the
functions have been cloned. This causes the BlockAddress to point to the old
values. Just wait until the functions have been cloned before copying the
initializers.
PR13163

llvm-svn: 194218
2013-11-07 20:14:51 +00:00
Bill Wendling 91e6f6e198 Add a 'deleteModule' method to the Linker class.
This deletes the Module ivar instead of having the LTO code generater do it. It
also sets the pointer to 'NULL', so that if it's used again it will abort
quickly.

llvm-svn: 192778
2013-10-16 08:59:57 +00:00
Will Dietz 981af0021b Add missing #include's to cctype when using isdigit/alpha/etc.
llvm-svn: 192519
2013-10-12 00:55:57 +00:00
Peter Collingbourne 3fa50f9b05 Implement function prefix data as an IR feature.
Previous discussion:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2013-July/063909.html

Differential Revision: http://llvm-reviews.chandlerc.com/D1191

llvm-svn: 190773
2013-09-16 01:08:15 +00:00
Rafael Espindola fac3a018d1 Error on linking appending globals with different unnamed_addr.
llvm-svn: 189950
2013-09-04 15:33:34 +00:00
Rafael Espindola fd9a9415f5 Fix linking of unnamed_addr in functions.
llvm-svn: 189945
2013-09-04 14:59:03 +00:00
Rafael Espindola d4885daefa Fix linking of unnamed_addr.
This was regression from r134829. When linking we have to be conservative. If
one of the symbols has a significant address, then the result should have it
too.

llvm-svn: 189935
2013-09-04 14:05:09 +00:00
James Molloy f6f121e277 Extend RemapInstruction and friends to take an optional new parameter, a ValueMaterializer.
Extend LinkModules to pass a ValueMaterializer to RemapInstruction and friends to lazily create Functions for lazily linked globals. This is a big win when linking small modules with large (mostly unused) library modules.

llvm-svn: 182776
2013-05-28 15:17:05 +00:00
Rafael Espindola aa9918aac7 Fix a performance bug in the Linker.
Now that we hava a convinient place to keep it, remeber the set of
identified structs as we merge modules.

This speeds up the linking of all the bitcode files in clang with the
gold plugin and -plugin-opt=emit-llvm (i.e., link only, no codegen) from
5:25 minutes to 13.6 seconds!

Patch by Xiaofei Wan!

llvm-svn: 181104
2013-05-04 05:05:18 +00:00
Rafael Espindola 287f18b4b8 Implement Linker::LinkModules with Linker::linkInModule.
Flipping which one is the implementation will let us optimize linkInModule.

llvm-svn: 181102
2013-05-04 04:08:02 +00:00
Rafael Espindola 3df61b7bef Now that Linker.cpp is almost empty, merge it into LinkModules.cpp.
Also remove unused includes.

llvm-svn: 181100
2013-05-04 03:48:37 +00:00
Filip Pizlo dec20e43c0 This patch breaks up Wrap.h so that it does not have to include all of
the things, and renames it to CBindingWrapping.h.  I also moved 
CBindingWrapping.h into Support/.

This new file just contains the macros for defining different wrap/unwrap 
methods.

The calls to those macros, as well as any custom wrap/unwrap definitions 
(like for array of Values for example), are put into corresponding C++ 
headers.

Doing this required some #include surgery, since some .cpp files relied 
on the fact that including Wrap.h implicitly caused the inclusion of a 
bunch of other things.

This also now means that the C++ headers will include their corresponding 
C API headers; for example Value.h must include llvm-c/Core.h.  I think 
this is harmless, since the C API headers contain just external function 
declarations and some C types, so I don't believe there should be any 
nasty dependency issues here.

llvm-svn: 180881
2013-05-01 20:59:00 +00:00
Eric Christopher 04d4e9312c Move C++ code out of the C headers and into either C++ headers
or the C++ files themselves. This enables people to use
just a C compiler to interoperate with LLVM.

llvm-svn: 180063
2013-04-22 22:47:22 +00:00