Commit Graph

314 Commits

Author SHA1 Message Date
Yaron Keren
407da8c267 Fix subprogram-linkonce-weak.ll and subprogram-linkonce-weak-odr.ll for Windows.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233375 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 13:52:12 +00:00
Duncan P. N. Exon Smith
c4eafd24f2 Verifier: Check accessors of MDLocation
Check accessors of `MDLocation`, and change them to `cast<>` down to the
right types.  Also add type-safe factory functions.

All the callers that handle broken code need to use the new versions of
the accessors (`getRawScope()` instead of `getScope()`) that still
return `Metadata*`.  This is also necessary for things like
`MDNodeKeyImpl<MDLocation>` (in LLVMContextImpl.h) that need to unique
the nodes when their operands might still be forward references of the
wrong type.

In the `Value` hierarchy, consumers that handle broken code use
`getOperand()` directly.  However, debug info nodes have a ton of
operands, and their order (even their existence) isn't stable yet.  It's
safer and more maintainable to add an explicit "raw" accessor on the
class itself.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233322 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-26 22:05:04 +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
6141f178a6 llvm-link: Verify input modules
Otherwise, broken input modules can cause assertions.  I've updated two
of the testcases that started failing (modules that had `Require` flags
but didn't meet their own requirements), but Rafael and I decided that
test/Linker/2011-08-22-ResolveAlias.ll should just be deleted outright
-- it's a leftover of the way llvm-gcc used to implement weakref.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233229 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-25 23:22:10 +00:00
Duncan P. N. Exon Smith
00aafa5d73 Linker: Stop using -gmlt test/Linker/subprogram-linkonce-weak.ll
As dblaikie pointed out, if I stop setting `emissionKind: 2` then the
backend won't do magical things on Linux vs. Darwin.  I had wrongly
assumed that there were stricter requirements on the input if we weren't
in line-tables-only mode, but apparently not.

With that knowledge, clean up this testcase a little more.

  - Set `emissionKind: 1`.
  - Add back checks for the weak version of @foo.
  - Check more robustly that we have the right subprograms by checking
    the `DW_AT_decl_file` and `DW_AT_decl_line` which now show up.
  - Check the line table in isolation (since it's no longer doubling as
    an indirect test for the subprogram of the weak version of @foo).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233221 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-25 21:36:41 +00:00
Duncan P. N. Exon Smith
3f972ab1bf Linker: Loosen checks slightly from r233207
According to at least one bot [1], function prologues aren't always
empty for these functions.  Skip that part of the follow-up check.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233214 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-25 20:51:21 +00:00
Duncan P. N. Exon Smith
151bc36220 Linker: Rewrite dwarfdump checks from r233164
Rewrite the checks from r233164 that I temporarily disabled in r233165.

It turns out that the line-tables only debug info we emit from `llc` is
(intentionally) different on Linux than on Darwin.  r218129 started
skipping emission of subprograms with no inlined subroutines, and
r218702 was a spiritual revert of that behaviour for Darwin.

I think we can still test this in a platform-neutral way.

  - Stop checking for the possibly missing `DW_TAG_subprogram` defining
    the debug info for the real version of `@foo`.
  - Start checking the line tables, ensuring that the right debug info
    was used to generate them (grabbing `DW_AT_low_pc` from the compile
    unit).
  - I changed up the line numbers used in the "weak" version so it's
    easier to follow.

This should hopefully finish off PR22792.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233207 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-25 19:57:42 +00:00
Duncan P. N. Exon Smith
2186876e87 Linker: Temporarily disable dwarfdump checks from r233164
At least one Linux bot [1] doesn't like my dwarfdump checks, so I've
disable those until I can investigate what's going on there.  I'll
continue to track this in PR22792.

[1]: http://bb.pgr.jp/builders/cmake-llvm-x86_64-linux/builds/22863

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233165 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-25 02:43:04 +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
David Blaikie
5a70dd1d82 [opaque pointer type] Add textual IR support for explicit type parameter to gep operator
Similar to gep (r230786) and load (r230794) changes.

Similar migration script can be used to update test cases, which
successfully migrated all of LLVM and Polly, but about 4 test cases
needed manually changes in Clang.

(this script will read the contents of stdin and massage it into stdout
- wrap it in the 'apply.sh' script shown in previous commits + xargs to
apply it over a large set of test cases)

import fileinput
import sys
import re

rep = re.compile(r"(getelementptr(?:\s+inbounds)?\s*\()((<\d*\s+x\s+)?([^@]*?)(|\s*addrspace\(\d+\))\s*\*(?(3)>)\s*)(?=$|%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|zeroinitializer|<|\[\[[a-zA-Z]|\{\{)", re.MULTILINE | re.DOTALL)

def conv(match):
  line = match.group(1)
  line += match.group(4)
  line += ", "
  line += match.group(2)
  return line

line = sys.stdin.read()
off = 0
for match in re.finditer(rep, line):
  sys.stdout.write(line[off:match.start()])
  sys.stdout.write(conv(match))
  off = match.end()
sys.stdout.write(line[off:])

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232184 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-13 18:20:45 +00:00
Paul Robinson
107918efa2 Emit correct linkage-name attribute based on DWARF version.
There are still 4 tests that check for DW_AT_MIPS_linkage_name,
because they specify DWARF 2 or 3 in the module metadata. So, I didn't
create an explicit version-based test for the attribute.

Differential Revision: http://reviews.llvm.org/D8227


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231880 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 22:44:45 +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
Duncan P. N. Exon Smith
b056aa798d DebugInfo: Move new hierarchy into place
Move the specialized metadata nodes for the new debug info hierarchy
into place, finishing off PR22464.  I've done bootstraps (and all that)
and I'm confident this commit is NFC as far as DWARF output is
concerned.  Let me know if I'm wrong :).

The code changes are fairly mechanical:

  - Bumped the "Debug Info Version".
  - `DIBuilder` now creates the appropriate subclass of `MDNode`.
  - Subclasses of DIDescriptor now expect to hold their "MD"
    counterparts (e.g., `DIBasicType` expects `MDBasicType`).
  - Deleted a ton of dead code in `AsmWriter.cpp` and `DebugInfo.cpp`
    for printing comments.
  - Big update to LangRef to describe the nodes in the new hierarchy.
    Feel free to make it better.

Testcase changes are enormous.  There's an accompanying clang commit on
its way.

If you have out-of-tree debug info testcases, I just broke your build.

  - `upgrade-specialized-nodes.sh` is attached to PR22564.  I used it to
    update all the IR testcases.
  - Unfortunately I failed to find way to script the updates to CHECK
    lines, so I updated all of these by hand.  This was fairly painful,
    since the old CHECKs are difficult to reason about.  That's one of
    the benefits of the new hierarchy.

This work isn't quite finished, BTW.  The `DIDescriptor` subclasses are
almost empty wrappers, but not quite: they still have loose casting
checks (see the `RETURN_FROM_RAW()` macro).  Once they're completely
gutted, I'll rename the "MD" classes to "DI" and kill the wrappers.  I
also expect to make a few schema changes now that it's easier to reason
about everything.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231082 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 17:24:31 +00:00
Reid Kleckner
2dc2d3f820 lit: Add 'cd' support to the internal shell and port some tests
The internal shell was already threading around a 'cwd' parameter. We
just have to make it mutable so that we can update it as the test script
executes.

If the shell ever grows support for environment variable substitution,
we could also implement support for export.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231017 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-02 21:33:18 +00:00
David Blaikie
7c9c6ed761 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230794 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 21:17:42 +00:00
David Blaikie
198d8baafb [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.

This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.

* This doesn't modify gep operators, only instructions (operators will be
  handled separately)

* Textual IR changes only. Bitcode (including upgrade) and changing the
  in-memory representation will be in separate changes.

* geps of vectors are transformed as:
    getelementptr <4 x float*> %x, ...
  ->getelementptr float, <4 x float*> %x, ...
  Then, once the opaque pointer type is introduced, this will ultimately look
  like:
    getelementptr float, <4 x ptr> %x
  with the unambiguous interpretation that it is a vector of pointers to float.

* address spaces remain on the pointer, not the type:
    getelementptr float addrspace(1)* %x
  ->getelementptr float, float addrspace(1)* %x
  Then, eventually:
    getelementptr float, ptr addrspace(1) %x

Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.

update.py:
import fileinput
import sys
import re

ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile(       r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")

def conv(match, line):
  if not match:
    return line
  line = match.groups()[0]
  if len(match.groups()[5]) == 0:
    line += match.groups()[2]
  line += match.groups()[3]
  line += ", "
  line += match.groups()[1]
  line += "\n"
  return line

for line in sys.stdin:
  if line.find("getelementptr ") == line.find("getelementptr inbounds"):
    if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
      line = conv(re.match(ibrep, line), line)
  elif line.find("getelementptr ") != line.find("getelementptr ("):
    line = conv(re.match(normrep, line), line)
  sys.stdout.write(line)

apply.sh:
for name in "$@"
do
  python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
  rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).

The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7636

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230786 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 19:29:02 +00:00
Akira Hatanaka
f3fae65fcc Add run line that was missing in r228999.
Also, change the run lines to use -allow-empty.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229118 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 16:00:03 +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
Duncan P. N. Exon Smith
a7a6be22eb Utils: Resolve cycles under distinct MDNodes
Track unresolved nodes under distinct `MDNode`s during `MapMetadata()`,
and resolve them at the end.  Previously, these cycles wouldn't get
resolved.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228180 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-04 19:44:34 +00:00
Duncan P. N. Exon Smith
37ac8d3622 IR: Move MDLocation into place
This commit moves `MDLocation`, finishing off PR21433.  There's an
accompanying clang commit for frontend testcases.  I'll attach the
testcase upgrade script I used to PR21433 to help out-of-tree
frontends/backends.

This changes the schema for `DebugLoc` and `DILocation` from:

    !{i32 3, i32 7, !7, !8}

to:

    !MDLocation(line: 3, column: 7, scope: !7, inlinedAt: !8)

Note that empty fields (line/column: 0 and inlinedAt: null) don't get
printed by the assembly writer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226048 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 22:27:36 +00:00
Duncan P. N. Exon Smith
68ee48f92e Utils: Handle remapping distinct MDLocations
Part of PR21433.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225921 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 01:29:32 +00:00
Duncan P. N. Exon Smith
74195b2df3 Utils: Add mapping for uniqued MDLocations
Still doesn't handle distinct ones.  Part of PR21433.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225914 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 01:20:27 +00:00
Duncan P. N. Exon Smith
3408708548 Utils: Keep distinct MDNodes distinct in MapMetadata()
Create new copies of distinct `MDNode`s instead of following the
uniquing `MDNode` logic.

Just like self-references (or other cycles), `MapMetadata()` creates a
new node.  In practice most calls use `RF_NoModuleLevelChanges`, in
which case nothing is duplicated anyway.

Part of PR22111.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225476 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-08 22:42:30 +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
f907a26bc2 Change the .ll syntax for comdats and add a syntactic sugar.
In order to make comdats always explicit in the IR, we decided to make
the syntax a bit more compact for the case of a GlobalObject in a
comdat with the same name.

Just dropping the $name causes problems for

@foo = globabl i32 0, comdat
$bar = comdat ...

and

declare void @foo() comdat
$bar = comdat ...

So the syntax is changed to

@g1 = globabl i32 0, comdat($c1)
@g2 = globabl i32 0, comdat

and

declare void @foo() comdat($c1)
declare void @foo() comdat

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225302 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 22:55:16 +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
Duncan P. N. Exon Smith
1ef70ff39b IR: Make metadata typeless in assembly
Now that `Metadata` is typeless, reflect that in the assembly.  These
are the matching assembly changes for the metadata/value split in
r223802.

  - Only use the `metadata` type when referencing metadata from a call
    intrinsic -- i.e., only when it's used as a `Value`.

  - Stop pretending that `ValueAsMetadata` is wrapped in an `MDNode`
    when referencing it from call intrinsics.

So, assembly like this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata !{i32 %v}, metadata !0)
      call void @llvm.foo(metadata !{i32 7}, metadata !0)
      call void @llvm.foo(metadata !1, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{metadata !3}, metadata !0)
      ret void, !bar !2
    }
    !0 = metadata !{metadata !2}
    !1 = metadata !{i32* @global}
    !2 = metadata !{metadata !3}
    !3 = metadata !{}

turns into this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata i32 %v, metadata !0)
      call void @llvm.foo(metadata i32 7, metadata !0)
      call void @llvm.foo(metadata i32* @global, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{!3}, metadata !0)
      ret void, !bar !2
    }
    !0 = !{!2}
    !1 = !{i32* @global}
    !2 = !{!3}
    !3 = !{}

I wrote an upgrade script that handled almost all of the tests in llvm
and many of the tests in cfe (even handling many `CHECK` lines).  I've
attached it (or will attach it in a moment if you're speedy) to PR21532
to help everyone update their out-of-tree testcases.

This is part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224257 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-15 19:07:53 +00:00
Duncan P. N. Exon Smith
8f616165e4 IR: Canonicalize metadata formatting, NFC
Canonicalize formatting of metadata to make it easier to upgrade via
scripts -- in particular, one line per metadata definition makes it more
`sed`-able.

This is preparation for changing the assembly syntax for metadata [1].

[1]: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20141208/248449.html

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224002 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 06:32:29 +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
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
83fbd8dcd2 Simplify the test. NFC.
Since the main file was empty, we can just copy the content of the Input file
into it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223666 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 17:22:06 +00:00
Rafael Espindola
bc1055c76d Simplify test. NFC.
This is just testing the largest merge mode for comdats. No need to use
hard to read names and fancy types.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223665 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 17:02:50 +00:00
Rafael Espindola
e77177b3ae Use CHECK-DAG to reduce the noise in an upcoming patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223663 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 16:46:52 +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
Duncan P. N. Exon Smith
09ba28c27c IR: Disallow function-local metadata attachments
Metadata attachments to instructions cannot be function-local.

This is part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223574 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-06 02:29:44 +00:00
Rafael Espindola
d3c3235ab3 Add a few extra cases to the test. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223417 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 00:02:42 +00:00
Rafael Espindola
fe137022a5 Convert test to use an extra Input file. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223414 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-04 23:31:21 +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
d9788e9372 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223043 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 16:32:20 +00:00
Rafael Espindola
7a551b7c6d 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222986 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 04:15:59 +00:00
Rafael Espindola
805b8166cf Add a test showing what the linker IdentifiedStructTypes is for.
Without this it could just be deleted and all tests would pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222985 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 03:20:57 +00:00
Rafael Espindola
f716393db9 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222923 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-28 16:41:24 +00:00
Rafael Espindola
c61674553b Add a testcase reduced from clang lto bootstrap on OS X.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222921 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-28 15:45:31 +00:00