Commit Graph

599 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith
125e3d3959 DebugInfo: Gut DISubprogram and DILexicalBlock*
Gut the `DIDescriptor` wrappers around `MDLocalScope` subclasses.  Note
that `DILexicalBlock` wraps `MDLexicalBlockBase`, not `MDLexicalBlock`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234850 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-14 03:40:37 +00:00
Duncan P. N. Exon Smith
1545953510 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234255 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-06 23:18:49 +00:00
Duncan P. N. Exon Smith
387a89bb36 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(...) {

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233302 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-26 18:35:30 +00:00
Duncan P. N. Exon Smith
a977f7e771 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233254 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-26 05:27:45 +00:00
Duncan P. N. Exon Smith
c89369a941 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(...) {

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233164 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-25 02:26:32 +00:00
Mehdi Amini
529919ff31 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>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231740 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 02:37:25 +00:00
Rafael Espindola
b6fd95ab41 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231442 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 00:50:21 +00:00
Mehdi Amini
c94da20917 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>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231270 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-04 18:43:29 +00:00
Juergen Ributzka
0a5c3015f8 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230988 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-02 18:59:38 +00:00
Manman Ren
bd26e6a006 [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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230290 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-24 00:45:56 +00:00
Benjamin Kramer
1a50a12b43 Prefer SmallVector::append/insert over push_back loops.
Same functionality, but hoists the vector growth out of the loop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229500 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-17 15:29:18 +00:00
Akira Hatanaka
ac844bf562 [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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228999 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 00:40:41 +00:00
Zachary Turner
c371307e60 Use ADDITIONAL_HEADER_DIRS in all LLVM CMake projects.
This allows IDEs to recognize the entire set of header files for
each of the core LLVM projects.

Differential Revision: http://reviews.llvm.org/D7526
Reviewed By: Chris Bieneman

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228798 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-11 03:28:02 +00:00
Manman Ren
0d12d4ebc6 [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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226592 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-20 19:24:59 +00:00
Rafael Espindola
68016e0a6e 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225562 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-10 00:07:30 +00:00
Duncan P. N. Exon Smith
c742e3a68d 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225397 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 21:32:27 +00:00
Rafael Espindola
d27b926340 Finish removing DestroySource.
Fixes pr21901.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224782 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-23 19:16:45 +00:00
Duncan P. N. Exon Smith
33ed2ef4ff 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224566 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 06:06:18 +00:00
Duncan P. N. Exon Smith
ee40b16641 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224487 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-18 01:05:33 +00:00
Duncan P. N. Exon Smith
80c5783c88 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224416 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-17 07:27:31 +00:00
Duncan P. N. Exon Smith
d4017d0489 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224389 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 23:23:41 +00:00
Rafael Espindola
e1bf514b2b Make the assert a bit stronger.
We should get no declarations in here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224382 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 22:29:43 +00:00
Michael Ilseman
f651477d66 Sink the isa into the assert
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224291 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-15 23:41:21 +00:00
Michael Ilseman
bc541ae238 Clean up warning about unused variable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224281 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-15 21:47:09 +00:00
Michael Ilseman
9f0d59ab46 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224277 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-15 21:36:29 +00:00
Duncan P. N. Exon Smith
dad20b2ae2 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.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223802 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 18:38:53 +00:00
Michael Ilseman
ebaf61e498 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223763 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 08:20:06 +00:00
Rafael Espindola
7fd7effa37 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223681 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 18:45:16 +00:00
Rafael Espindola
dcc44c64c1 Don't crash when the key of a comdat is lazily linked.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223673 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 18:05:48 +00:00
Rafael Espindola
968f0454b8 Move the ValueMap lookup inside linkFunctionBody. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223659 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 14:25:26 +00:00
Rafael Espindola
eaa2992eb2 Use range loops. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223658 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 14:20:10 +00:00
Rafael Espindola
e305256ca2 Use range loops. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223657 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 14:05:33 +00:00
Rafael Espindola
7779b87b25 Fix linking of prologue data.
It would crash when the function was lazy linked.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223656 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 13:44:38 +00:00
Rafael Espindola
254e67955f Simple style fixes.
* Use a range loop.
* Move simple continue checks earlier.
* clang-format.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223654 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 13:35:09 +00:00
Rafael Espindola
95d1d167d0 Move materialize/Dematerialize calls to linkFunctionBody. NFC.
Just less code duplication.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223653 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 13:29:33 +00:00
Benjamin Kramer
2991725fe2 Turn some DenseMaps that are only used for set operations into DenseSets.
DenseSet has better memory efficiency now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223589 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-06 19:22:54 +00:00
Rafael Espindola
9423af6b70 Remove dead code. We are only lazy about functions with bodies.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223521 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 21:36:06 +00:00
Rafael Espindola
f117c8ae03 Simplify the loop linking function bodies. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223512 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 21:04:36 +00:00
Rafael Espindola
98821ee350 Remove unused arguments. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223503 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 19:35:07 +00:00
Rafael Espindola
24ba29981c Refactor duplicated code. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223486 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 17:53:15 +00:00
Rafael Espindola
dd6794f01d Small cleanup on how we clear constant variables. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223474 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 16:05:19 +00:00
Rafael Espindola
46cbde27ce Use an early return. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223470 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 15:42:30 +00:00
Rafael Espindola
7eaee304ab linkGlobalVariableProto never returns null. Simplify the caller. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223424 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 00:30:47 +00:00
Rafael Espindola
aa8cddcd3a Move merging of alignment to a central location. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223418 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 00:09:02 +00:00
Rafael Espindola
55d5ea3be3 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223278 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-03 22:36:37 +00:00
Rafael Espindola
eee41dbb65 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223215 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-03 07:18:23 +00:00
Peter Collingbourne
bb660fc192 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223189 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-03 02:08:38 +00:00
Rafael Espindola
f97b79e09e Use a continue to reduce indentation and clang-format. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223067 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 19:17:46 +00:00
Rafael Espindola
6eee2bbbbb Use a range loop. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223066 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 19:08:07 +00:00
Rafael Espindola
e8f8c64e35 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223057 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 18:42:18 +00:00