Commit Graph

30 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith e7e1d0c706 Reapply "AsmPrinter: Change DIEValue to be stored by value"
This reverts commit r238350, effectively reapplying r238349 after fixing
(all?) the problems, all somehow related to how I was using
`AlignedArrayCharUnion<>` inside `DIEValue`:

  - MSVC can only handle `sizeof()` on types, not values.  Change the
    assert.
  - GCC doesn't know the `is_trivially_copyable` type trait.  Instead of
    asserting it, add destructors.
  - Call placement new even when constructing POD (i.e., the pointers).
  - Instead of copying the char buffer, copy the casted classes.

I've left in a couple of `static_assert`s that I think both MSVC and GCC
know how to handle.  If the bots disagree with me, I'll remove them.

  - Check that the constructed type is either standard layout or a
    pointer.  This protects against a programming error: we really want
    the "small" `DIEValue`s to be small and simple, so don't
    accidentally change them not to be.
  - Similarly, check that the size of the buffer is no bigger than a
    `uint64_t` or a pointer.  (I thought checking against
    `sizeof(uint64_t)` would be good enough, but Chandler suggested that
    pointers might sometimes be bigger than that in the context of
    sanitizers.)

I've also committed r238359 in the meantime, which introduces a
DIEValue.def to simplify dispatching between the various types (thanks
to a review comment by David Blaikie).  Without that, this commit would
be almost unintelligible.

Here's the original commit message:
--
Change `DIEValue` to be stored/passed/etc. by value, instead of
reference.  It's now a discriminated union, with a `Val` field storing
the actual type.  The classes that used to inherit from `DIEValue` no
longer do.  There are two categories of these:

  - Small values fit in a single pointer and are stored by value.
  - Large values require auxiliary storage, and are stored by reference.

The only non-mechanical change is to tools/dsymutil/DwarfLinker.cpp.  It
was relying on `DIEInteger`s being passed around by reference, so I
replaced that assumption with a `PatchLocation` type that stores a safe
reference to where the `DIEInteger` lives instead.

This commit causes a temporary regression in memory usage, since I've
left merging `DIEAbbrevData` into `DIEValue` for a follow-up commit.  I
measured an increase from 845 MB to 879 MB, around 3.9%.  The follow-up
drops it lower than the starting point, and I've only recently brought
the memory this low anyway, so I'm committing these changes separately
to keep them incremental.  (I also considered swapping the commits, but
the other one first would cause a lot more code churn.)

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
--

llvm-svn: 238362
2015-05-27 22:14:58 +00:00
Duncan P. N. Exon Smith 583bc03829 Revert "AsmPrinter: Change DIEValue to be stored by value"
This reverts commit r238349, since it caused some errors on bots:
  - std::is_trivially_copyable isn't available until GCC 5.0.
  - It was complaining about strict aliasing with my use of
    ArrayCharUnion.

llvm-svn: 238350
2015-05-27 19:30:27 +00:00
Duncan P. N. Exon Smith 7735b48a8b AsmPrinter: Change DIEValue to be stored by value
Change `DIEValue` to be stored/passed/etc. by value, instead of
reference.  It's now a discriminated union, with a `Val` field storing
the actual type.  The classes that used to inherit from `DIEValue` no
longer do.  There are two categories of these:

  - Small values fit in a single pointer and are stored by value.
  - Large values require auxiliary storage, and are stored by reference.

The only non-mechanical change is to tools/dsymutil/DwarfLinker.cpp.  It
was relying on `DIEInteger`s being passed around by reference, so I
replaced that assumption with a `PatchLocation` type that stores a safe
reference to where the `DIEInteger` lives instead.

This commit causes a temporary regression in memory usage, since I've
left merging `DIEAbbrevData` into `DIEValue` for a follow-up commit.  I
measured an increase from 845 MB to 879 MB, around 3.9%.  The follow-up
drops it lower than the starting point, and I've only recently brought
the memory this low anyway, so I'm committing these changes separately
to keep them incremental.  (I also considered swapping the commits, but
the other one first would cause a lot more code churn.)

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

llvm-svn: 238349
2015-05-27 19:22:50 +00:00
Rafael Espindola 0709a7bd1a Move alignment from MCSectionData to MCSection.
This starts merging MCSection and MCSectionData.

There are a few issues with the current split between MCSection and
MCSectionData.

* It optimizes the the not as important case. We want the production
of .o files to be really fast, but the split puts the information used
for .o emission in a separate data structure.

* The ELF/COFF/MachO hierarchy is not represented in MCSectionData,
leading to some ad-hoc ways to represent the various flags.

* It makes it harder to remember where each item is.

The attached patch starts merging the two by moving the alignment from
MCSectionData to MCSection.

Most of the patch is actually just dropping 'const', since
MCSectionData is mutable, but MCSection was not.

llvm-svn: 237936
2015-05-21 19:20:38 +00:00
Duncan P. N. Exon Smith a9308c49ef IR: Give 'DI' prefix to debug info metadata
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`.  The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.

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

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

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

llvm-svn: 236120
2015-04-29 16:38:44 +00:00
Lang Hames 9ff69c8f4d [AsmPrinter] Make AsmPrinter's OutStreamer member a unique_ptr.
AsmPrinter owns the OutStreamer, so an owning pointer makes sense here. Using a
reference for this is crufty.

llvm-svn: 235752
2015-04-24 19:11:51 +00:00
Duncan P. N. Exon Smith 60635e39b6 DebugInfo: Drop rest of DIDescriptor subclasses
Delete the remaining subclasses of (the already deleted) `DIDescriptor`.
Part of PR23080.

llvm-svn: 235404
2015-04-21 18:44:06 +00:00
Duncan P. N. Exon Smith 7348ddaa74 DebugInfo: Gut DIVariable and DIGlobalVariable
Gut all the non-pointer API from the variable wrappers, except an
implicit conversion from `DIGlobalVariable` to `DIDescriptor`.  Note
that if you're updating out-of-tree code, `DIVariable` wraps
`MDLocalVariable` (`MDVariable` is a common base class shared with
`MDGlobalVariable`).

llvm-svn: 234840
2015-04-14 02:22:36 +00:00
Rafael Espindola 063d725fd7 Store an optional section start label in MCSection.
This makes code that uses section relative expressions (debug info) simpler and
less brittle.

This is still a bit awkward as the symbol is created late and has to be
stored in a mutable field.

I will move the symbol creation earlier in the next patch.

llvm-svn: 231802
2015-03-10 16:58:10 +00:00
Frederic Riss 9412d63f68 Move emitDIE and emitAbbrevs to AsmPrinter. NFC.
(They are called emitDwarfDIE and emitDwarfAbbrevs in their new home)

llvm-dsymutil wants to reuse that code, but it doesn't have a DwarfUnit or
a DwarfDebug object to call those. It has access to an AsmPrinter though.

Having emitDIE in the AsmPrinter also removes the DwarfFile dependency
on DwarfDebug, and thus the patch drops that field.

Differential Revision: http://reviews.llvm.org/D8024

llvm-svn: 231210
2015-03-04 02:30:17 +00:00
Adrian Prantl ca7e470221 Debug Info: Support variables that are described by more than one MMI
table entry. This happens when SROA splits up an alloca and the resulting
allocas cannot be lowered to SSA values because their address is passed
to a function.

Fixes PR22502.

llvm-svn: 228764
2015-02-10 23:18:28 +00:00
David Blaikie e7d473461e Revert "PR21408: Workaround the appearance of duplicate variables due to problems when inlining two calls to the same function from the same call site."
The underlying bug has been fixed in r226736 so there's no need to
workaround this anymore.

This reverts commit r220923.

llvm-svn: 226842
2015-01-22 17:49:59 +00:00
Chandler Carruth d9903888d9 [cleanup] Re-sort all the #include lines in LLVM using
utils/sort_includes.py.

I clearly haven't done this in a while, so more changed than usual. This
even uncovered a missing include from the InstrProf library that I've
added. No functionality changed here, just mechanical cleanup of the
include order.

llvm-svn: 225974
2015-01-14 11:23:27 +00:00
David Blaikie ae57e66e36 Sink dwarf unit length emission down into DwarfUnit::emitHeader
This allows the CU label to be emitted only for compile units, as
they're the only ones that need it (so they can be referenced from
pubnames)

llvm-svn: 221072
2014-11-01 23:59:23 +00:00
David Blaikie 983bfea0d0 Remove DwarfUnit::LabelEnd in favor of computing the length of the section directly
This was a compile-unit specific label (unused in type units) and seems
unnecessary anyway when we can more easily directly compute the size of
the compile unit.

llvm-svn: 221067
2014-11-01 23:07:14 +00:00
David Blaikie fb2efde341 Correct assert text from r220923
Noticed in post-commit review by Adrian Prantl.

llvm-svn: 220967
2014-10-31 16:45:36 +00:00
David Blaikie 76fd43c653 PR21408: Workaround the appearance of duplicate variables due to problems when inlining two calls to the same function from the same call site.
llvm-svn: 220923
2014-10-30 20:20:11 +00:00
David Blaikie 80e5b1ebd1 DebugInfo: Sink DwarfDebug::ScopeVariables down into DwarfFile
(part of refactoring to allow subprogram emission in both the skeleton
and main units to enable -gmlt-like data to be included in the skeleton
for live inlined backtracing purposes)

llvm-svn: 220578
2014-10-24 17:57:34 +00:00
David Blaikie f4c504e03c DebugInfo: Remove DwarfDebug::addScopeVariable now that it's just a trivial wrapper
llvm-svn: 220542
2014-10-24 00:43:47 +00:00
David Blaikie 1dd573db45 DebugInfo: Remove DwarfDebug::CurrentFnArguments since we have to handle argument ordering of other arguments (abstract arguments) in the same way and already have code for that too.
While refactoring this code I was confused by both the name I had
introduced (addNonArgumentVariable... but it has all this logic to
handle argument numbering and keep things in order?) and by the
redundancy. Seems when I fixed the misordered inlined argument handling,
I didn't realize it was mostly redundant with the argument ordering code
(which I may've also written, I'm not sure). So let's just rely on the
more general case.

The only oddity in output this produces is that it means when we emit
all the variables for the current function, we don't track when we've
finished the argument variables and are about to start the local
variables and insert DW_AT_unspecified_parameters (for varargs
functions) there. Instead it ends up after the local variables, scopes,
etc. But this isn't invalid and doesn't cause DWARF consumers problems
that I know of... so we'll just go with that because it makes the code
nice & simple.

(though, let's see what the buildbots have to say about this - *crosses
fingers*)

There will be some cleanup commits to follow to remove the now trivial
wrappers, etc.

llvm-svn: 220527
2014-10-23 22:27:50 +00:00
David Blaikie 3b5c84008d DebugInfo: Sink DwarfDebug::addNonArgumentScopeVariable into DwarfFile.
llvm-svn: 220520
2014-10-23 22:04:30 +00:00
David Blaikie bcfa8a56b1 Remove explicit (void) use of DwarfFile::DD that was accidentally left in r220452.
Caught in post-commit review by Frédéric.

llvm-svn: 220487
2014-10-23 16:12:58 +00:00
David Blaikie f299947bfa [DebugInfo] Sink DwarfDebug::addCurrentFnArgument down into DwarfFile.
Variable handling will be sunk into DwarfFile so that abstract variables
and the like can be shared across multiple CUs (to handle cross-CU
inlining, for example).

llvm-svn: 220453
2014-10-23 00:16:05 +00:00
David Blaikie 2b22b1e9a2 [DebugInfo] Add DwarfDebug& to DwarfFile.
Use the DwarfDebug in one function that previously took it as a
parameter, and lay the foundation for use this for other operations
coming soon.

llvm-svn: 220452
2014-10-23 00:16:03 +00:00
David Blaikie 6741bb09bb Remove the unused string section symbol parameter from DwarfFile::emitStrings
And since it /looked/ like the DwarfStrSectionSym was unused, I tried
removing it - but then it turned out that DwarfStringPool was
reconstructing the same label (and expecting it to have already been
emitted) and uses that.

So I kept it around, but wanted to pass it in to users - since it seemed
a bit silly for DwarfStringPool to have it passed in and returned but
itself have no use for it. The only two users don't handle strings in
both .dwo and .o files so they only ever need the one symbol - no need
to keep it (and have an unused symbol) in the DwarfStringPool used for
fission/.dwo.

Refactor a bunch of accelerator table usage to remove duplication so I
didn't have to touch 4-5 callers.

llvm-svn: 217628
2014-09-11 21:12:48 +00:00
David Blaikie daefdbf3ad Encapsulate the DWARF string pool in a separate type.
Pulls out some more code from some of the rather monolithic DWARF
classes. Unlike the address table, the string table won't move up into
DwarfDebug - each DWARF file has its own string table (but there can be
only one address table).

llvm-svn: 207277
2014-04-25 21:34:35 +00:00
David Blaikie adcde36ceb Return DIE by reference instead of pointer from DwarfUnit::getUnitDie
llvm-svn: 207255
2014-04-25 18:35:57 +00:00
David Blaikie e226b08ee9 Separate out the DWARF address pool into its own type/files.
llvm-svn: 207022
2014-04-23 21:04:59 +00:00
David Blaikie 05e736fb8a clang-format r207010
llvm-svn: 207016
2014-04-23 19:44:08 +00:00
David Blaikie 85f80d7122 Split out DwarfFile from DwarfDebug into its own .h/.cpp files.
Some of these types (DwarfDebug in particular) are quite large to begin
with (and I keep forgetting whether DwarfFile is in DwarfDebug or
DwarfUnit... ) so having a few smaller files seems like goodness.

llvm-svn: 207010
2014-04-23 18:54:00 +00:00