Commit Graph

641 Commits

Author SHA1 Message Date
Bjorn Steinbrink
d36bbe9c89 Ignore all duplicate frame index expression
Some passes might duplicate calls to llvm.dbg.declare creating
duplicate frame index expression which currently trigger an assertion
which is meant to catch erroneous, overlapping fragment declarations.
But identical frame index expressions are just redundant and don't
actually conflict with each other, so we can be more lenient and just
ignore the duplicates.

Reviewers: aprantl, rnk

Subscribers: llvm-commits, JDevlieghere

Differential Revision: https://reviews.llvm.org/D38540

llvm-svn: 315279
2017-10-10 07:46:17 +00:00
Peter Collingbourne
b52e23669c IR: Represent -ggnu-pubnames with a flag on the DICompileUnit.
This allows the flag to be persisted through to LTO.

Differential Revision: https://reviews.llvm.org/D37655

llvm-svn: 313078
2017-09-12 21:50:41 +00:00
Eugene Zelenko
6e07bfd0d9 [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 311124
2017-08-17 21:26:39 +00:00
Adrian Prantl
61b39b2aec Remove unused includes of MachineLocation.h (NFC)
llvm-svn: 309824
2017-08-02 15:32:18 +00:00
Adrian Prantl
f45e6462ca Fix an assertion failure when duplicate dbg.declares are present.
This fixes PR33157.
https://bugs.llvm.org//show_bug.cgi?id=33157

We might also think about disallowing duplicate dbg.declare intrinsics
entirely, but this may complicate some passes needlessly.

llvm-svn: 305244
2017-06-12 22:41:06 +00:00
David Blaikie
07963bd1d1 DebugInfo: Do not emit empty CUs
Consistent with GCC and addresses a shortcoming with ThinLTO where many
imported CUs may end up being empty (because the functions imported from
them either ended up not being used (and were then discarded, since
they're imported as available_externally) or optimized away entirely).

Test cases previously testing empty CUs (either intentionally, or
because they didn't need anything more complicated) had a trivial 'int'
or similar basic type added to their retained types list.

This is a first order approximation - a deeper implementation could do
things like:

1) Be more lazy about construction of the CU - for example if two CUs
containing a single identical retained type are linked together, with
this change one of the two CUs will be produced but empty (since a
duplicate type won't be produced).

2) Go further and invert all the CU links the same way the subprogram
link is inverted - keep named CU lists of retained types, macros, etc,
and have those link back to the CU. Then if they're emitted, the CU is
emitted, but never otherwise - this would allow the metadata itself to
be dropped earlier too, though it seems unlikely that's an important
optimization as there shouldn't be many CUs relative to the number of
other entities.

llvm-svn: 304020
2017-05-26 18:52:56 +00:00
David Blaikie
b3cee2fb42 DebugInfo: Produce debug_{gnu_}pub{names,types} entries when explicitly requested, even in -gmlt or when empty
Turns out gold doesn't use the DW_AT_GNU_pubnames to decide whether to
parse the rest of the DIEs when building gdb-index. This causes gold to
trip over LLVM's output when there are DW_FORM_ref_addr present.

Gold does use the presence of a debug_gnu_pub{names,types} entry for the
CU to skip parsing the debug_info portion, so make sure that's included
even when empty (technically, when empty there couldn't be any ref_addr
anyway - it only came up when gmlt didn't produce any (even non-empty)
pubnames - but given what that reveals about gold's implementation, this
seems like a good thing to do for consistency).

llvm-svn: 303894
2017-05-25 18:50:28 +00:00
David Blaikie
488393f822 DWARF: Avoid cross-CU references under Fission
Turns out that the Fission/Split DWARF package format (DWP) is currently
insufficient to handle cross-CU (ref_addr) references. So for now,
duplicate any debug info needed in these situations:
* inlined_subroutine's abstract_origin
* inlined variable's abstract_origin
* types

Keep the ref_addr behavior in general, including in the split DWARF
inline debug info that can be emitted into the object files for online
symbolication.
Keep a flag to use the old (ref_addr) behavior for testing ways of
addressing this limitation in the DWP tool (& for those not using DWP
packaging).

llvm-svn: 302858
2017-05-12 01:13:45 +00:00
Reid Kleckner
f7c0980c10 Elide argument copies during instruction selection
Summary:
Avoids tons of prologue boilerplate when arguments are passed in memory
and left in memory. This can happen in a debug build or in a release
build when an argument alloca is escaped.  This will dramatically affect
the code size of x86 debug builds, because X86 fast isel doesn't handle
arguments passed in memory at all. It only handles the x86_64 case of up
to 6 basic register parameters.

This is implemented by analyzing the entry block before ISel to identify
copy elision candidates. A copy elision candidate is an argument that is
used to fully initialize an alloca before any other possibly escaping
uses of that alloca. If an argument is a copy elision candidate, we set
a flag on the InputArg. If the the target generates loads from a fixed
stack object that matches the size and alignment requirements of the
alloca, the SelectionDAG builder will delete the stack object created
for the alloca and replace it with the fixed stack object. The load is
left behind to satisfy any remaining uses of the argument value. The
store is now dead and is therefore elided. The fixed stack object is
also marked as mutable, as it may now be modified by the user, and it
would be invalid to rematerialize the initial load from it.

Supersedes D28388

Fixes PR26328

Reviewers: chandlerc, MatzeB, qcolombet, inglorion, hans

Subscribers: igorb, llvm-commits

Differential Revision: https://reviews.llvm.org/D29668

llvm-svn: 296683
2017-03-01 21:42:00 +00:00
Adrian Prantl
67c2442210 Debug Info: Sort frame index expressions before emitting them.
This fixes PR31381, which caused an assertion and/or invalid debug info.

This affects debug variables that have multiple fragments in the MMI
side (i.e.: in the stack frame) table.
rdar://problem/30571676

llvm-svn: 295486
2017-02-17 19:42:32 +00:00
David Blaikie
b2fbb4b276 Refactor DebugHandlerBase a bit to common non-debug-having-function filtering
llvm-svn: 295354
2017-02-16 18:48:33 +00:00
David Blaikie
38b74bf249 DebugInfo: Address non-deterministic output (iterating a SmallPtrSet) in 289697
Post-commit review feedback from Adrian Prantl.

Hopefully this fixes that up :)

llvm-svn: 289892
2016-12-15 23:37:38 +00:00
David Blaikie
b461468958 DebugInfo: Improve type safety and simplify some subprogram finalization code
This probably ended up this way aften the subprogram<>function link
inversion and debug info metadata schema changes.

llvm-svn: 289697
2016-12-14 19:38:39 +00:00
Adrian Prantl
941fa7588b [DIExpression] Introduce a dedicated DW_OP_LLVM_fragment operation
so we can stop using DW_OP_bit_piece with the wrong semantics.

The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html

The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.

Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.

Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809

llvm-svn: 288683
2016-12-05 18:04:47 +00:00
Greg Clayton
35630c3357 This change removes the dependency on DwarfDebug that was used for DW_FORM_ref_addr by making a new DIEUnit class in DIE.cpp.
The DIEUnit class represents a compile or type unit and it owns the unit DIE as an instance variable. This allows anyone with a DIE, to get the unit DIE, and then get back to its DIEUnit without adding any new ivars to the DIE class. Why was this needed? The DIE class has an Offset that is always the CU relative DIE offset, not the "offset in debug info section" as was commented in the header file (the comment has been corrected). This is great for performance because most DIE references are compile unit relative and this means most code that accessed the DIE's offset didn't need to make it into a compile unit relative offset because it already was. When we needed to emit a DW_FORM_ref_addr though, we needed to find the absolute offset of the DIE by finding the DIE's compile/type unit. This class did have the absolute debug info/type offset and could be added to the CU relative offset to compute the absolute offset. With this change we can easily get back to a DIE's DIEUnit which will have this needed offset. Prior to this is required having a DwarfDebug and required calling:

DwarfCompileUnit *DwarfDebug::lookupUnit(const DIE *CU) const;
Now we can use the DIEUnit class to do so without needing DwarfDebug. All clients now use DIEUnit objects (the DwarfDebug stack and the DwarfLinker). A follow on patch for the DWARF generator will also take advantage of this.

Differential Revision: https://reviews.llvm.org/D27170

llvm-svn: 288399
2016-12-01 18:56:29 +00:00
Matthias Braun
ef331eff5a Move VariableDbgInfo from MachineModuleInfo to MachineFunction
VariableDbgInfo is per function data, so it makes sense to have it with
the function instead of the module.

This is a necessary step to have machine module passes work properly.

Differential Revision: https://reviews.llvm.org/D27186

llvm-svn: 288292
2016-11-30 23:48:50 +00:00
Greg Clayton
e65439797a Rely on a single DWARF version instead of having two copies
This patch makes AsmPrinter less reliant on DwarfDebug by relying on the DWARF version in the AsmPrinter's MCStreamer's MCContext. This allows us to remove the redundant DWARF version from DwarfDebug. It also lets us change code that used to access the AsmPrinter's DwarfDebug just to get to the DWARF version by changing the DWARF version accessor on AsmPrinter so that it grabs the version from its MCStreamer's MCContext.

Differential Revision: https://reviews.llvm.org/D27032

llvm-svn: 287839
2016-11-23 23:30:37 +00:00
David Majnemer
0a16c22846 Use range algorithms instead of unpacking begin/end
No functionality change is intended.

llvm-svn: 278417
2016-08-11 21:15:00 +00:00
David Blaikie
c53e18d93a DWARF: Omit DW_AT_APPLE attributes (except ObjC ones) when not targeting LLDB
These attributes aren't used by other debuggers (& may be confused with
other DWARF extensions) so they just waste space (about 1.5% on .dwo
file size on a random large program I tested).

We could remove the ObjC property ones too, but I figured they were
probably more necessary when trying to understand ObjC (I could be wrong
though) & so any debugger interested in working with ObjC would use
them, perhaps? (also, there are some legacy tests in Clang that test for
them - making it one of those annoying cross-project commits and/or
cleanup to refactor those tests)

llvm-svn: 270613
2016-05-24 21:19:28 +00:00
Paul Robinson
101772128a [DwarfDebug] Make tuning predicates private, should be used only in ctor.
llvm-svn: 269859
2016-05-17 22:53:20 +00:00
Adrian Prantl
6323ddf99c Debug Info: Introduce a DwarfDebug::UseDWARF2Bitfields flag
instead of having DwarfUnit query the debugger tuning options.

Follow-up commmit to r269827.
Thanks to Paul Robinson for pointing this out!

llvm-svn: 269840
2016-05-17 21:07:16 +00:00
Amjad Aboud
72da9391f0 Reverting 268054 & 268063 as they caused PR27579.
llvm-svn: 268150
2016-04-30 01:44:07 +00:00
Amjad Aboud
293ee8bba1 Recommitted r264280 "Supporting all entities declared in lexical scope in LLVM debug info."
After fixing PR26942 in r267004.

llvm-svn: 268054
2016-04-29 16:07:55 +00:00
Duncan P. N. Exon Smith
a59d3e5af8 DebugInfo: Remove MDString-based type references
Eliminate DITypeIdentifierMap and make DITypeRef a thin wrapper around
DIType*.  It is no longer legal to refer to a DICompositeType by its
'identifier:', and DIBuilder no longer retains all types with an
'identifier:' automatically.

Aside from the bitcode upgrade, this is mainly removing logic to resolve
an MDString-based reference to an actualy DIType.  The commits leading
up to this have made the implicit type map in DICompileUnit's
'retainedTypes:' field superfluous.

This does not remove DITypeRef, DIScopeRef, DINodeRef, and
DITypeRefArray, or stop using them in DI-related metadata.  Although as
of this commit they aren't serving a useful purpose, there are patchces
under review to reuse them for CodeView support.

The tests in LLVM were updated with deref-typerefs.sh, which is attached
to the thread "[RFC] Lazy-loading of debug info metadata":

  http://lists.llvm.org/pipermail/llvm-dev/2016-April/098318.html

llvm-svn: 267296
2016-04-23 21:08:00 +00:00
Paul Robinson
43d1e45347 [DWARF] Force a linkage_name on an inlined subprogram's abstract origin.
When we suppress linkage names, for a non-inlined subprogram the name
can still be found in the object-file symbol table, because we have
the code address of the subprogram.  This is not necessarily the case
for an inlined subprogram, so we still want to emit the linkage name
in the DWARF.  Put this on the abstract-origin DIE because it's common
to all inlined instances.

Differential Revision: http://reviews.llvm.org/D18706

llvm-svn: 266692
2016-04-18 22:41:41 +00:00
Mehdi Amini
b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Adrian Prantl
75819aedf6 [PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

llvm-svn: 266446
2016-04-15 15:57:41 +00:00
Adrian Prantl
3891e9e859 Drop debug info for DISubprograms that are not referenced by anything
This patch drops the debug info for all DISubprograms that are
(a) not attached to an llvm::Function and
(b) not indirectly reachable via inline scopes from any surviving Function and
(c) not reachable from a type (i.e.: member functions).

Background: I'm currently working on a patch to reverse the pointers
between DICompileUnit and DISubprogram (for more info check Duncan's RFC
on lazy-loading of debug info metadata
http://lists.llvm.org/pipermail/llvm-dev/2016-March/097419.html).
The idea is to remove the list of subprograms from DICompileUnit and
instead point to the owning compile unit from each DISubprogram.
After doing this all DISubprograms fulfilling the above criteria will be
implicitly dropped unless we go through an extra effort to preserve them.

http://reviews.llvm.org/D18477
<rdar://problem/25256815>

llvm-svn: 265876
2016-04-09 18:10:22 +00:00
Reid Kleckner
01bc66a8ce Revert "Recommitted r263424 "Supporting all entities declared in lexical scope in LLVM debug info." After fixing PR26942 (the fix is included in this commit)."
This reverts commit r264280.

This broke building Chromium for iOS. We'll upload a reproducer to the
PR soon.

llvm-svn: 264334
2016-03-24 20:38:49 +00:00
Amjad Aboud
6ff7e10052 Recommitted r263424 "Supporting all entities declared in lexical scope in LLVM debug info."
After fixing PR26942 (the fix is included in this commit).

Differential Revision: http://reviews.llvm.org/D18350

llvm-svn: 264280
2016-03-24 13:30:16 +00:00
Benjamin Kramer
1082fa66a5 Revert "Recommitted r261633 "Supporting all entities declared in lexical scope in LLVM debug info." After fixing PR26715 at r263379."
This reverts commit r263424. Breaks self-host.

llvm-svn: 263437
2016-03-14 14:58:36 +00:00
Amjad Aboud
ab0378b16c Recommitted r261633 "Supporting all entities declared in lexical scope in LLVM debug info."
After fixing PR26715 at r263379.

llvm-svn: 263424
2016-03-14 12:03:20 +00:00
Hans Wennborg
d3661cd140 Revert r261633 "Supporting all entities declared in lexical scope in LLVM debug info."
This and the corresponding Clang change caused PR26715.

llvm-svn: 261671
2016-02-23 19:17:03 +00:00
Amjad Aboud
fc8f296782 Supporting all entities declared in lexical scope in LLVM debug info.
Differential Revision: http://reviews.llvm.org/D15976

llvm-svn: 261633
2016-02-23 13:36:51 +00:00
Adrian Prantl
6f4746b11a DbgVariable: Add an accessor for the common case of a single expression
belonging to a single DBG_VALUE instruction.

NFC

llvm-svn: 261167
2016-02-17 22:19:59 +00:00
Peter Collingbourne
7c384ccea2 DwarfDebug: emit type units immediately.
Rather than storing type units in a vector and emitting them at the end
of code generation, emit them immediately and destroy them, reclaiming the
memory we were using for their DIEs.

In one benchmark carried out against Chromium's 50 largest (by bitcode
file size) translation units, total peak memory consumption with type units
decreased by median 17%, or by 7% when compared against disabling type units.

Tested using check-{llvm,clang}, the GDB 7.5 test suite (with
'-fdebug-types-section') and by eyeballing llvm-dwarfdump output on those
Chromium translation units with split DWARF both disabled and enabled, and
verifying that the only changes were to addresses and abbreviation ordering.

Differential Revision: http://reviews.llvm.org/D17118

llvm-svn: 260578
2016-02-11 19:57:46 +00:00
Reid Kleckner
f9c275fe0a [codeview] Describe int local variables using .cv_def_range
Summary:
Refactor common value, scope, and label tracking logic out of DwarfDebug
into a common base class called DebugHandlerBase.

Update an old LLVM IR test case to avoid an assertion in LexicalScopes.

Reviewers: dblaikie, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16931

llvm-svn: 260432
2016-02-10 20:55:49 +00:00
Amjad Aboud
8bbce8ad8e Improved macro emission in dwarf.
Changed emitting offset of macinfo entry into compiler unit DIE to use "addSectionLabel" method rather than explicitly calculating size/offset of macro entry.

Differential Revision: http://reviews.llvm.org/D16292

llvm-svn: 259358
2016-02-01 14:09:41 +00:00
Amjad Aboud
c077841492 Fixed few comments.
llvm-svn: 258658
2016-01-24 08:18:55 +00:00
Amjad Aboud
d7cfb48485 Added support for macro emission in dwarf (supporting DWARF version 4).
Differential Revision: http://reviews.llvm.org/D15495

llvm-svn: 257060
2016-01-07 14:28:20 +00:00
Paul Robinson
6c27a2c40e Set debugger tuning from TargetOptions (NFC)
Differential Revision: http://reviews.llvm.org/D15427

llvm-svn: 255810
2015-12-16 19:58:30 +00:00
Yaron Keren
9ffee46d45 Erase unused FunctionDIs variables after r252219.
llvm-svn: 252401
2015-11-07 10:21:25 +00:00
Ivan Krasin
298639a5fd Move imported entities into DwarfCompilationUnit to speed up LTO linking.
Summary:
In particular, this CL speeds up the official Chrome linking with LTO by
1.8x.

See more details in https://crbug.com/542426

Reviewers: dblaikie

Subscribers: jevinskie

Differential Revision: http://reviews.llvm.org/D13918

llvm-svn: 251353
2015-10-26 21:36:35 +00:00
Benjamin Kramer
7fa42c8a8c [AsmPrinter] Prune dead code. NFC.
I left all (dead) print and dump methods in place.

llvm-svn: 250433
2015-10-15 17:16:32 +00:00
Craig Topper
862d5d8322 Remove 'const' from some ArrayRefs. ArrayRefs are already immutable. NFC
llvm-svn: 248693
2015-09-28 00:15:34 +00:00
Paul Robinson
78046b49a9 Make DW_AT_[MIPS_]linkage_name optional, and off by default for SCE.
Mangled "linkage" names can be huge, and if the debugger (or other
tools) have no use for them, the size savings can be very impressive
(on the order of 40%).

Add one test for controlling behavior, and modify a number of tests to
either stop using linkage names, or make llc emit them (so these tests
will still run when the default triple is for PS4).

Differential Revision: http://reviews.llvm.org/D11374

llvm-svn: 244678
2015-08-11 21:36:45 +00:00
Duncan P. N. Exon Smith
ed013cd221 DI: Remove DW_TAG_arg_variable and DW_TAG_auto_variable
Remove the fake `DW_TAG_auto_variable` and `DW_TAG_arg_variable` tags,
using `DW_TAG_variable` in their place Stop exposing the `tag:` field at
all in the assembly format for `DILocalVariable`.

Most of the testcase updates were generated by the following sed script:

    find test/ -name "*.ll" -o -name "*.mir" |
    xargs grep -l 'DILocalVariable' |
    xargs sed -i '' \
      -e 's/tag: DW_TAG_arg_variable, //' \
      -e 's/tag: DW_TAG_auto_variable, //'

There were only a handful of tests in `test/Assembly` that I needed to
update by hand.

(Note: a follow-up could change `DILocalVariable::DILocalVariable()` to
set the tag to `DW_TAG_formal_parameter` instead of `DW_TAG_variable`
(as appropriate), instead of having that logic magically in the backend
in `DbgVariable`.  I've added a FIXME to that effect.)

llvm-svn: 243774
2015-07-31 18:58:39 +00:00
Paul Robinson
b9de106d04 Add a "debugger tuning" concept that allows us to fine-tune how we
emit debug info, according to the preferences of the different
debuggers used on various targets.
Darwin and FreeBSD default to tuning for LLDB; PS4 defaults to tuning for
the SCE (Sony Computer Entertainment) debugger.  All others default to GDB.

Differential Revision: http://reviews.llvm.org/D8506

llvm-svn: 242338
2015-07-15 22:04:54 +00:00
Adrian Prantl
ee5feafc0f Debug Info: Add basic support for external types references.
This is a necessary prerequisite for bootstrapping the emission
of debug info inside modules.

- Adds a FlagExternalTypeRef to DICompositeType.
  External types must have a unique identifier.
- External type references are emitted using a forward declaration
  with a DW_AT_signature([DW_FORM_ref_sig8]) based on the UID.

http://reviews.llvm.org/D9612

llvm-svn: 242302
2015-07-15 17:01:41 +00:00
Adrian Prantl
857237ee70 Service the doxygen comments in DwarfUnit and DwarfDebug.
llvm-svn: 242046
2015-07-13 18:25:29 +00:00
David Blaikie
d51dea67b3 Revert "[DWARF] Fix debug info generation for function static variables, typedefs, and records"
Caused PR24008

This reverts commit 37cb5f1c2db9f42d29f26b215585f56bb64ae4f5.

llvm-svn: 241176
2015-07-01 18:07:16 +00:00
Michael Kuperstein
01e8185c31 [DWARF] Fix debug info generation for function static variables, typedefs, and records
Function static variables, typedefs and records (class, struct or union) declared inside
a lexical scope were associated with the function as their parent scope, rather than the
lexical scope they are defined or declared in.

This fixes PR19238

Patch by: amjad.aboud@intel.com
Differential Revision: http://reviews.llvm.org/D9758

llvm-svn: 241153
2015-07-01 12:33:11 +00:00
Duncan P. N. Exon Smith
e6cc531b1a AsmPrinter: Rewrite initialization of DbgVariable, NFC
There are three types of `DbgVariable`:
  - alloca variables, created based on the MMI table,
  - register variables, created based on DBG_VALUE instructions, and
  - optimized-out variables.

This commit reconfigures `DbgVariable` to make it easier to tell which
kind we have, and make initialization a little clearer.

For MMI/alloca variables, `FrameIndex.size()` must always equal
`Expr.size()`, and there shouldn't be an `MInsn`.  For register
variables (with a `MInsn`), `FrameIndex` must be empty, and `Expr`
should have 0 or 1 element depending on whether it has a complex
expression (registers with multiple locations use `DebugLocListIndex`).
Optimized-out variables shouldn't have any of these fields.

Moreover, this separates DBG_VALUE initialization until after the
variable is created, simplifying logic in a future commit that changes
`collectVariableInfo()` to stop creating empty .debug_loc entries/lists.

llvm-svn: 240243
2015-06-21 16:50:43 +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
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
2fbe13540a DebugInfo: Delete subclasses of DIScope
Delete subclasses of (the already defunct) `DIScope`, updating users to
use the raw pointers from the `Metadata` hierarchy directly.

llvm-svn: 235356
2015-04-20 22:10:08 +00:00
Duncan P. N. Exon Smith
c62468859a DebugInfo: Delete old subclasses of DIType
Delete subclasses of (the already deleted) `DIType` in favour of
directly using pointers from the `Metadata` hierarchy.

While `DICompositeType` wraps `MDCompositeTypeBase` and `DIDerivedType`
wraps `MDDerivedTypeBase`, most uses of each really meant the more
specific `MDCompositeType` and `MDDerivedType`.

llvm-svn: 235351
2015-04-20 21:17:32 +00:00
Duncan P. N. Exon Smith
9928a909c6 DebugInfo: Remove DIType
This is the last major parent class, so I'll probably start deleting
classes in batches now.  Looks like many of the references to the DI*
hierarchy were updated organically along the way.

llvm-svn: 235331
2015-04-20 18:52:06 +00:00
Duncan P. N. Exon Smith
ed557b55ee DebugInfo: Remove DIDescriptor from the DebugInfo API
Stop using `DIDescriptor` and its subclasses in the `DebugInfoFinder`
API, as well as the rest of the API hanging around in `DebugInfo.h`.

llvm-svn: 235240
2015-04-17 23:20:10 +00:00
Duncan P. N. Exon Smith
364a3005f2 AsmPrinter: Create a unified .debug_loc stream
This commit removes `DebugLocList` and replaces it with
`DebugLocStream`.

  - `DebugLocEntry` no longer contains its byte/comment streams.
  - The `DebugLocEntry` list for a variable/inlined-at pair is allocated
    on the stack, and released right after `DebugLocEntry::finalize()`
    (possible because of the refactoring in r231023).  Now, only one
    list is in memory at a time now.
  - There's a single unified stream for the `.debug_loc` section that
    persists, stored in the new `DebugLocStream` data structure.

The last point is important: this collapses the nested `SmallVector<>`s
from `DebugLocList` into unified streams.  We previously had something
like the following:

    vec<tuple<Label, CU,
              vec<tuple<BeginSym, EndSym,
                        vec<Value>,
                        vec<char>,
                        vec<string>>>>>

A `SmallVector` can avoid allocations, but is statically fairly large
for a vector: three pointers plus the size of the small storage, which
is the number of elements in small mode times the element size).
Nesting these is expensive, since an inner vector's size contributes to
the element size of an outer one.  (Nesting any vector is expensive...)

In the old data structure, the outer vector's *element* size was 632B,
excluding allocation costs for when the middle and inner vectors
exceeded their small sizes.  312B of this was for the "three" pointers
in the vector-tree beneath it.  If you assume 1M functions with an
average of 10 variable/inlined-at pairs each (in an LTO scenario),
that's almost 6GB (besides inner allocations), with almost 3GB for the
"three" pointers.

This came up in a heap profile a little while ago of a `clang -flto -g`
bootstrap, with `DwarfDebug::collectVariableInfo()` using something like
10-15% of the total memory.

With this commit, we have:

    tuple<vec<tuple<Label, CU, Offset>>,
          vec<tuple<BeginSym, EndSym, Offset, Offset>>,
          vec<char>,
          vec<string>>

The offsets are used to create `ArrayRef` slices of adjacent
`SmallVector`s.  This reduces the number of vectors to four (unrelated
to the number of variable/inlined-at pairs), and caps the number of
allocations at the same number.

Besides saving memory and limiting allocations, this is NFC.

I don't know my way around this code very well yet, but I wonder if we
could go further: why stream to a side-table, instead of directly to the
output stream?

llvm-svn: 235229
2015-04-17 21:34:47 +00:00
Duncan P. N. Exon Smith
237662429d Remove dead code, NFC
llvm-svn: 235225
2015-04-17 21:06:49 +00:00
Duncan P. N. Exon Smith
78a9527062 AsmPrinter: Simplify logic for debug info intrinsics' !dbg attachments
These are required, so just assume they're there.

llvm-svn: 235138
2015-04-16 22:12:59 +00:00
Duncan P. N. Exon Smith
b0b0e4958b DebugInfo: DIRef<> => TypedDebugNodeRef<>
Delete `DIRef<>`, and replace the remaining uses of it with
`TypedDebugNodeRef<>`.  To minimize code churn, I've added typedefs from
`MDTypeRef` to `DITypeRef` (etc.).

llvm-svn: 235071
2015-04-16 02:24:01 +00:00
Duncan P. N. Exon Smith
b105564015 DebugInfo: Gut DIType and subclasses
Continuing PR23080, gut `DIType` and its various subclasses, leaving
behind thin wrappers around the pointer types in the new debug info
hierarchy.

llvm-svn: 235064
2015-04-16 01:01:28 +00:00
Duncan P. N. Exon Smith
62e0f454a0 DebugInfo: Remove 'inlinedAt:' field from MDLocalVariable
Remove 'inlinedAt:' from MDLocalVariable.  Besides saving some memory
(variables with it seem to be single largest `Metadata` contributer to
memory usage right now in -g -flto builds), this stops optimization and
backend passes from having to change local variables.

The 'inlinedAt:' field was used by the backend in two ways:

 1. To tell the backend whether and into what a variable was inlined.
 2. To create a unique id for each inlined variable.

Instead, rely on the 'inlinedAt:' field of the intrinsic's `!dbg`
attachment, and change the DWARF backend to use a typedef called
`InlinedVariable` which is `std::pair<MDLocalVariable*, MDLocation*>`.
This `DebugLoc` is already passed reliably through the backend (as
verified by r234021).

This commit removes the check from r234021, but I added a new check
(that will survive) in r235048, and changed the `DIBuilder` API in
r235041 to require a `!dbg` attachment whose 'scope:` is in the same
`MDSubprogram` as the variable's.

If this breaks your out-of-tree testcases, perhaps the script I used
(mdlocalvariable-drop-inlinedat.sh) will help; I'll attach it to PR22778
in a moment.

llvm-svn: 235050
2015-04-15 22:29:27 +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
Duncan P. N. Exon Smith
6a0320a991 DebugInfo: Gut DIExpression
Completely gut `DIExpression`, turning it into a simple wrapper around
`MDExpression *`.  There are two bits of magic left:

  - It's constructed from `const MDExpression*` but convertible to
    `MDExpression*`.
  - It's default-constructed to `nullptr`.

Otherwise, it should behave quite like a raw pointer.  Once I've done
the same to the rest of the `DIDescriptor` subclasses, I'll come back to
delete them entirely (and update call sites as necessary to deal with
the missing magic).

llvm-svn: 234832
2015-04-14 01:12:42 +00:00
Duncan P. N. Exon Smith
000fa2c646 DebugInfo: Remove DITypedArray<>, replace with typedefs
Replace all uses of `DITypedArray<>` with `MDTupleTypedArrayWrapper<>`
and `MDTypeRefArray`.  The APIs are completely different, but the
provided functionality is the same: treat an `MDTuple` as if it's an
array of a particular element type.

To simplify this patch a bit, I've temporarily typedef'ed
`DebugNodeArray` to `DIArray` and `MDTypeRefArray` to `DITypeArray`.
I've also temporarily conditionalized the accessors to check for null --
eventually these should be changed to asserts and the callers should
check for null themselves.

There's a tiny accompanying patch to clang.

llvm-svn: 234290
2015-04-07 04:14:33 +00:00
Duncan P. N. Exon Smith
e686f1591f CodeGen: Stop using DIDescriptor::is*() and auto-casting
Same as r234255, but for lib/CodeGen and lib/Target.

llvm-svn: 234258
2015-04-06 23:27:40 +00:00
Duncan P. N. Exon Smith
a5099dce62 DebugInfo: Remove DIDescriptor::Verify()
Remove `DIDescriptor::Verify()` and the `Verify()`s from subclasses.
They had already been gutted, and just did an `isa<>` check.

In a couple of cases I've temporarily dropped the check entirely, but
subsequent commits are going to disallow conversions to the
`DIDescriptor`s directly from `MDNode`, so the checks will come back in
another form soon enough.

llvm-svn: 234201
2015-04-06 19:49:39 +00:00
Rafael Espindola
9ab09237dc Centralize the handling of unique ids for temporary labels.
Before this patch code wanting to create temporary labels for a given entity
(function, cu, exception range, etc) had to keep its own counter to have stable
symbol names.

createTempSymbol would still add a suffix to make sure a new symbol was always
returned, but it kept a single counter. Because of that, if we were to use
just createTempSymbol("cu_begin"), the label could change from cu_begin42 to
cu_begin43 because some other code started using temporary labels.

Simplify this by just keeping one counter per prefix and removing the various
specialized counters.

llvm-svn: 232535
2015-03-17 20:07:06 +00:00
Rafael Espindola
51067848e7 Remove dead code. NFC.
llvm-svn: 232472
2015-03-17 13:09:01 +00:00
Duncan P. N. Exon Smith
e9d379c038 IR: Take advantage of -verify checks for MDExpression
Now that we check `MDExpression` during `-verify` (r232299), make
the `DIExpression` wrapper more strict:

  - remove redundant checks in `DebugInfoVerifier`,
  - overload `get()` to `cast_or_null<MDExpression>` (superseding
    `getRaw()`),
  - stop checking for null in any accessor, and
  - remove `DIExpression::Verify()` entirely in favour of
    `MDExpression::isValid()`.

There is still some logic in this class, mostly to do with high-level
iterators; I'll defer cleaning up those until the rest of the wrappers
are similarly strict.

llvm-svn: 232412
2015-03-16 21:03:55 +00:00
Rafael Espindola
f1a13f5ad5 Print section start labels when first switching to the section.
This is less brittle and avoids polluting the start of the file with every
debug section.

llvm-svn: 231898
2015-03-11 00:51:37 +00:00
Rafael Espindola
6b9998b3eb Create symbols marking the start of a section earlier.
This lets us pass the symbol to the constructor and avoid the mutable field.

This also opens the way for outputting the symbol only when needed, instead
of outputting them at the start of the file.

llvm-svn: 231859
2015-03-10 22:00:25 +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
Rafael Espindola
3c066d1da3 Remove effectively dead code.
Switching back and forth between sections does nothing (other than producing
larger .s files).

llvm-svn: 231790
2015-03-10 14:48:01 +00:00
Rafael Espindola
07c03d316d Use the existing begin and end symbol for debug info.
llvm-svn: 231338
2015-03-05 02:05:42 +00:00
Paul Robinson
78cc0821f0 Support standard DWARF TLS opcode; Darwin and PS4 use it.
Differential Revision: http://reviews.llvm.org/D8018

llvm-svn: 231286
2015-03-04 20:55:11 +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
92da14b244 Refactor DebugLocDWARFExpression so it doesn't require access to the
TargetRegisterInfo. DebugLocEntry now holds a buffer with the raw bytes
of the pre-calculated DWARF expression.

Ought to be NFC, but it does slightly alter the output format of the
textual assembly.

This reapplies 230930 without the assertion in DebugLocEntry::finalize()
because not all Machine registers can be lowered into DWARF register
numbers and floating point constants cannot be expressed.

llvm-svn: 231023
2015-03-02 22:02:33 +00:00
Adrian Prantl
2185aa179d Revert "Refactor DebugLocDWARFExpression so it doesn't require access to the"
This reverts commit 230975 to investigate buildbot breakage.

llvm-svn: 231004
2015-03-02 20:01:54 +00:00
Adrian Prantl
d50bca7314 Refactor DebugLocDWARFExpression so it doesn't require access to the
TargetRegisterInfo. DebugLocEntry now holds a buffer with the raw bytes
of the pre-calculated DWARF expression.

Ought to be NFC, but it does slightly alter the output format of the
textual assembly.

This reapplies 230930 with a relaxed assertion in DebugLocEntry::finalize()
that allows for empty DWARF expressions for constant FP values.

llvm-svn: 230975
2015-03-02 17:21:06 +00:00
Nico Weber
968ceddca9 Revert r230930, it caused PR22747.
llvm-svn: 230932
2015-03-02 04:37:11 +00:00
Adrian Prantl
e2c9e64532 Refactor DebugLocDWARFExpression so it doesn't require access to the
TargetRegisterInfo. DebugLocEntry now holds a buffer with the raw bytes
of the pre-calculated DWARF expression.

Ought to be NFC, but it does slightly alter the output format of the
textual assembly.

llvm-svn: 230930
2015-03-02 02:38:18 +00:00
Rafael Espindola
e8fd00dab0 Simplify arange output.
Move SectionMap to its only user (emitDebugARanges) and
reorder to save a call to sort.

llvm-svn: 230693
2015-02-26 22:02:02 +00:00
Eric Christopher
ffc5ff32d1 80-column fixups.
llvm-svn: 229527
2015-02-17 20:02:28 +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
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
Adrian Prantl
092d9489ed Debug Info: Move the complex expression handling (=the remainder) of
emitDebugLocValue() into DwarfExpression.

Ought to be NFC, but it actually uncovered a bug in the debug-loc-asan.ll
testcase. The testcase checks that the address of variable "y" is stored
at [RSP+16], which also lines up with the comment.
It also check(ed) that the *value* of "y" is stored in RDI before that,
but that is actually incorrect, since RDI is the very value that is
stored in [RSP+16]. Here's the assembler output:

	movb	2147450880(%rcx), %r8b
	#DEBUG_VALUE: bar:y <- RDI
	cmpb	$0, %r8b
	movq	%rax, 32(%rsp)          # 8-byte Spill
	movq	%rsi, 24(%rsp)          # 8-byte Spill
	movq	%rdi, 16(%rsp)          # 8-byte Spill
.Ltmp3:
	#DEBUG_VALUE: bar:y <- [RSP+16]

Fixed the comment to spell out the correct register and the check to
expect an address rather than a value.

Note that the range that is emitted for the RDI location was and is still
wrong, it claims to begin at the function prologue, but really it should
start where RDI is first assigned.

llvm-svn: 225851
2015-01-13 23:39:11 +00:00
Frederic Riss
e541e0b327 Make DIE.h a public CodeGen header.
dsymutil would like to use all the AsmPrinter/MCStreamer infrastructure
to stream out the DWARF. In order to do so, it will reuse the DIE object
and so this header needs to be public.

The interface exposed here has some corners that cannot be used without a
DwarfDebug object, but clients that want to stream Dwarf can just avoid
these.

Differential Revision: http://reviews.llvm.org/D6695

llvm-svn: 225208
2015-01-05 21:29:41 +00:00
David Blaikie
9bfd7a9f43 Move cross-unit DIE caching to the DwarfFile level, so it doesn't interfere with fission-gmlt data and produce skeleton<>full unit cross referencing.
llvm-svn: 221305
2014-11-04 22:12:18 +00:00
David Blaikie
192b45c1ef DebugInfo: Sink accelerator table lists down (GlobalNames/Types) into DwarfCompileUnit
llvm-svn: 221083
2014-11-02 06:16:39 +00:00
David Blaikie
f6dac29a83 Sink DwarfDebug::AbstractSPDies down into DwarfFile
This is the first big step to allowing gmlt-like inline scope
information in the skeleton CU. While this commit doesn't change the
functionality, it's only a small step to call
"constructAbstractSubprogramDIE" on both the InfoHolder and the
SkeletonHolder (when in use) and that will at least create the abstract
SP dies in that case, though still not creating the other subprograms.

llvm-svn: 221051
2014-11-01 17:21:26 +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
0dc623c232 Remove DwarfDebug::FirstCU as it has no use
It was only being used as a flag to identify the lack of debug info from
within endModule - use the section labels for that instead.

llvm-svn: 220575
2014-10-24 17:53:38 +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