Commit Graph

175 Commits

Author SHA1 Message Date
837f19eb80 AsmWriter: Escape string fields in metadata
Properly escape string fields in metadata.  I've added a spot-check with
direct coverage for `MDFile::getFilename()`, but we'll get more coverage
once the hierarchy is moved into place (since this comes up in various
checked-in testcases).

I've replicated the `if` logic using the `ShouldSkipEmpty` flag
(although a follow-up commit is going to change how often this flag is
specified); no NFCI other than escaping the string fields.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230875 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-28 22:20:16 +00:00
9973291e83 AsmWriter: Extract writeStringField(), NFCI
Extract logic for escaping a string field in the new debug info
hierarchy from `GenericDebugNode`.  A follow-up commit will use it far
more widely (hence the dead code for `ShouldSkipEmpty`).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230873 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-28 22:16:56 +00:00
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
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
344ea29148 IR: Drop newline from AssemblyWriter::printMDNodeBody()
Remove a newline from `AssemblyWriter::printMDNodeBody()`, and add one
to `AssemblyWriter::writeMDNode()`.  NFCI for assembly output.

However, this drops an inconsistent newline from `Metadata::print()`
when `this` is an `MDNode`.  Now the newline added by `Metadata::dump()`
won't look so verbose.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230565 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-25 22:46:38 +00:00
3a955f3e68 IR: Annotate dump methods with LLVM_DUMP_METHOD
It turns out we have a macro to ensure that debuggers can access
`dump()` methods.  Use it.  Hopefully this will prevent me (and others)
from committing crimes like in r223802 (search for /10000/, or just see
the fix in r224407).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230555 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-25 22:08:21 +00:00
9f8d4037a6 AsmParser/Writer: Handle symbolic constants in DI 'flags:'
Parse (and write) symbolic constants in debug info `flags:` fields.
This prevents a readability (and CHECK-ability) regression with the new
debug info hierarchy.

Old (well, current) assembly, with pretty-printing:

    !{!"...\\0016387", ...} ; ... [public] [rvalue reference]

Flags field without this change:

   !MDDerivedType(flags: 16387, ...)

Flags field with this change:

   !MDDerivedType(flags: DIFlagPublic | DIFlagRValueReference, ...)

As discussed in the review thread, this isn't a final state.  Most of
these flags correspond to `DW_AT_` symbolic constants, and we might
eventually want to support arbitrary attributes in some form.  However,
as it stands now, some of the flags correspond to other concepts (like
`FlagStaticMember`); until things are refactored this is the simplest
way to move forward without regressing assembly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230111 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-21 01:02:18 +00:00
ea8cbe9782 Bitcode: Stop assuming non-null fields
When writing the bitcode serialization for the new debug info hierarchy,
I assumed two fields would never be null.

Drop that assumption, since it's brittle (and crashes the
`BitcodeWriter` if wrong), and is a check better left for the verifier
anyway.  (No need for a bitcode upgrade here, since the new hierarchy is
still not in place.)

The fields in question are `MDCompileUnit::getFile()` and
`MDDerivedType::getBaseType()`, the latter of which isn't null in
test/Transforms/Mem2Reg/ConvertDebugInfo2.ll (see !14, a pointer to
nothing).  While the testcase might have bitrotted, there's no reason
for the bitcode format to rely on non-null for metadata operands.

This also fixes a bug in `AsmWriter` where if the `file:` is null it
isn't emitted (caught by the double-round trip in the testcase I'm
adding) -- this is a required field in `LLParser`.

I'll circle back to ConvertDebugInfo2.  Once the specialized nodes are
in place, I'll be trying to turn the debug info verifier back on by
default (in the newer module pass form committed r206300) and throwing
more logic in there.  If the testcase has bitrotted (as opposed to me
not understanding the schema correctly) I'll fix it then.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229960 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-20 03:17:58 +00:00
eac950e408 IR: Drop scope from MDTemplateParameter
Follow-up to r229740, which removed `DITemplate*::getContext()` after my
upgrade script revealed that scopes are always `nullptr` for template
parameters.  This is the other shoe: drop `scope:` from
`MDTemplateParameter` and its two subclasses.  (Note: a bitcode upgrade
would be pointless, since the hierarchy hasn't been moved into place.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229791 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 00:37:21 +00:00
b5026b0b83 IR: Swap order of name and value in MDEnum
Put the name before the value in assembly for `MDEnum`.  While working
on the testcase upgrade script for the new hierarchy, I noticed that it
"looks nicer" to have the name first, since it lines the names up in the
(somewhat typical) case that they have a common prefix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229747 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 21:16:33 +00:00
66981fe208 Removing LLVM_DELETED_FUNCTION, as MSVC 2012 was the last reason for requiring the macro. NFC; LLVM edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229340 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 22:54:22 +00:00
6a390dc584 AsmWriter/Bitcode: MDImportedEntity
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229025 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:46:02 +00:00
3bfa8d00ae AsmWriter/Bitcode: MDObjCProperty
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229024 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:43:22 +00:00
a034e076c2 AsmWriter/Bitcode: MDExpression
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229023 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:42:09 +00:00
a342d827bd AsmWriter/Bitcode: MDLocalVariable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229022 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:39:44 +00:00
fbc547da81 AsmWriter/Bitcode: MDGlobalVariable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229020 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:35:40 +00:00
8921bbca59 AsmWriter/Bitcode: MDTemplate{Type,Value}Parameter
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229019 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:34:32 +00:00
7bd3d1d3bd AsmWriter/Bitcode: MDNamespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229018 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:32:09 +00:00
246f0931ff AsmWriter/Bitcode: MDLexicalBlockFile
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229017 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:30:42 +00:00
c7be07e636 AsmWriter/Bitcode: MDLexicalBlock
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229016 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:29:28 +00:00
4730b909f6 AsmWriter: MDSubprogram: Recognize DW_VIRTUALITY in 'virtuality'
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229015 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:28:16 +00:00
ed356a925a AsmWriter/Bitcode: MDSubprogram
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229014 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:26:47 +00:00
37742c3591 AsmWriter/Bitcode: MDCompileUnit
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229013 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:25:10 +00:00
1c092c03ba AsmWriter/Bitcode: MDSubroutineType
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229011 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:22:59 +00:00
65e1227b37 AsmWriter: MDCompositeType: Recognize DW_LANG in 'runtimeLang'
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229010 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:21:25 +00:00
dacf0004cb AsmWriter/Bitcode: MDDerivedType and MDCompositeType
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229009 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:20:38 +00:00
192d9c3b6f AsmWriter/Bitcode: MDFile
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229007 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:19:14 +00:00
95d7135727 AsmWriter: MDBasicType: Recognize DW_ATE in 'encoding'
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229006 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:17:35 +00:00
57b4c150ca AsmWriter/Bitcode: MDBasicType
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229005 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:14:58 +00:00
aa7c94359c AsmWriter/Bitcode: MDEnumerator
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229004 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:14:11 +00:00
b984c49449 AsmWriter/Bitcode: MDSubrange
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229003 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:10:38 +00:00
14fcfef23b IR: Add specialized debug info metadata nodes
Add specialized debug info metadata nodes that match the `DIDescriptor`
wrappers (used by `DIBuilder`) closely.  Assembly and bitcode support to
follow soon (it'll mostly just be obvious), but this sketches in today's
schema.  This is the first big commit (well, the only *big* one aside
from the testcase changes that'll come when I move this into place) for
PR22464.

I've marked a bunch of obvious changes as `TODO`s in the source; I plan
to make those changes promptly after this hierarchy is moved underneath
`DIDescriptor`, but for now I'm aiming mostly to match the status quo.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228640 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 00:52:32 +00:00
ab2855852e AsmWriter: Extract writeTag(), NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228447 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-06 22:28:05 +00:00
8b07f1bd5f AsmWriter: Extract writeMetadataAsOperand(), NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228446 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-06 22:27:22 +00:00
1602e58745 AsmParser: Recognize DW_TAG_* constants
Recognize `DW_TAG_` constants in assembly, and output it by default for
`GenericDebugNode`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228042 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-03 21:56:01 +00:00
6adbfa3815 IR: Assembly and bitcode for GenericDebugNode
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228041 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-03 21:54:14 +00:00
cee1699e9f IR: DwarfNode => DebugNode, NFC
These things are potentially used for non-DWARF data (see the discussion
in PR22235), so take the `Dwarf` out of the name.  Since the new name
gives fewer clues, update the doxygen to properly describe what they
are.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226874 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-22 22:47:44 +00:00
0a9f921686 IR: Introduce GenericDwarfNode
As part of PR22235, introduce `DwarfNode` and `GenericDwarfNode`.  The
former is a metadata node with a DWARF tag.  The latter matches our
current (generic) schema of a header with string (and stringified
integer) data and an arbitrary number of operands.

This doesn't move it into place yet; that change will require a large
number of testcase updates.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226529 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-20 00:01:43 +00:00
b0617860b5 IR: Merge UniquableMDNode back into MDNode, NFC
As pointed out in r226501, the distinction between `MDNode` and
`UniquableMDNode` is confusing.  When we need subclasses of `MDNode`
that don't use all its functionality it might make sense to break it
apart again, but until then this makes the code clearer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226520 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 23:13:14 +00:00
a0ed724a44 IR: Remove isa<UniquableMDNode>, NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226488 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 19:10:14 +00:00
bf13dd03e7 IR: Always print MDLocation line
Print `MDLocation`'s `line` field even when it's 0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226046 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 22:14:26 +00:00
d640962656 IR: Add MDLocation class
Add a new subclass of `UniquableMDNode`, `MDLocation`.  This will be the
IR version of `DebugLoc` and `DILocation`.  The goal is to rename this
to `DILocation` once the IR classes supersede the `DI`-prefixed
wrappers.

This isn't used anywhere yet.  Part of PR21433.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225824 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 20:44:56 +00:00
120c186fde IR: Split out writeMDTuple(), NFC
Prepare for more subclasses of `UniquableMDNode` than `MDTuple`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225732 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 23:45:31 +00:00
f416d72973 IR: Add 'distinct' MDNodes to bitcode and assembly
Propagate whether `MDNode`s are 'distinct' through the other types of IR
(assembly and bitcode).  This adds the `distinct` keyword to assembly.

Currently, no one actually calls `MDNode::getDistinct()`, so these nodes
only get created for:

  - self-references, which are never uniqued, and
  - nodes whose operands are replaced that hit a uniquing collision.

The concept of distinct nodes is still not quite first-class, since
distinct-ness doesn't yet survive across `MapMetadata()`.

Part of PR22111.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225474 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-08 22:38:29 +00:00
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
02a8d1bcfd IR: Stop printing 'metadata' in Metadata::print()
Stop printing `metadata` in `Metadata::print()` and
`Metadata::printAsOperand()`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224327 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 07:40:31 +00:00
2ebd1efc08 IR: Make MDNode::dump() useful by adding addresses
It's horrible to inspect `MDNode`s in a debugger.  All of their operands
that are `MDNode`s get dumped as `<badref>`, since we can't assign
metadata slots in the context of a `Metadata::dump()`.  (Why not?  Why
not assign numbers lazily?  Because then each time you called `dump()`,
a given `MDNode` could have a different lazily assigned number.)

Fortunately, the C memory model gives us perfectly good identifiers for
`MDNode`.  Add pointer addresses to the dumps, transforming this:

    (lldb) e N->dump()
    !{i32 662302, i32 26, <badref>, null}

    (lldb) e ((MDNode*)N->getOperand(2))->dump()
    !{i32 4, !"foo"}

into:

    (lldb) e N->dump()
    !{i32 662302, i32 26, <0x100706ee0>, null}

    (lldb) e ((MDNode*)0x100706ee0)->dump()
    !{i32 4, !"foo"}

and this:

    (lldb) e N->dump()
    0x101200248 = !{<badref>, <badref>, <badref>, <badref>, <badref>}

    (lldb) e N->getOperand(0)
    (const llvm::MDOperand) $0 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(1)
    (const llvm::MDOperand) $1 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(2)
    (const llvm::MDOperand) $2 = {
      MD = 0x0000000101200058
    }
    (lldb) e N->getOperand(3)
    (const llvm::MDOperand) $3 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(4)
    (const llvm::MDOperand) $4 = {
      MD = 0x0000000101200058
    }
    (lldb) e ((MDNode*)0x00000001012004e0)->dump()
    !{}

    (lldb) e ((MDNode*)0x0000000101200058)->dump()
    !{null}

into:

    (lldb) e N->dump()
    !{<0x1012004e0>, <0x1012004e0>, <0x101200058>, <0x1012004e0>, <0x101200058>}

    (lldb) e ((MDNode*)0x1012004e0)->dump()
    !{}

    (lldb) e ((MDNode*)0x101200058)->dump()
    !{null}

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224325 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 07:09:37 +00:00
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
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
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