Commit Graph

3527 Commits

Author SHA1 Message Date
David Majnemer 3128b10cdc [CodeView] Add support for emitting S_UDT for typedefs
Emit a S_UDT record for typedefs.  We still need to do something for
class types.

Differential Revision: http://reviews.llvm.org/D21149

llvm-svn: 272813
2016-06-15 18:00:01 +00:00
Sanjoy Das 0272be206a Don't force SP-relative addressing for statepoints
Summary:
...  when the offset is not statically known.

Prioritize addresses relative to the stack pointer in the stackmap, but
fallback gracefully to other modes of addressing if the offset to the
stack pointer is not a known constant.

Patch by Oscar Blumberg!

Reviewers: sanjoy

Subscribers: llvm-commits, majnemer, rnk, sanjoy, thanm

Differential Revision: http://reviews.llvm.org/D21259

llvm-svn: 272756
2016-06-15 05:35:14 +00:00
David Majnemer 577be0fed3 [CodeView] Don't emit debuginfo for imported symbols
Emitting symbol information requires us to have a definition for the
symbol.  A symbol reference is insufficient.

This fixes PR28123.

llvm-svn: 272738
2016-06-15 00:19:52 +00:00
Peter Collingbourne 96efdd6107 IR: Introduce local_unnamed_addr attribute.
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.

This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
  the normal rule that the global must have a unique address can be broken without
  being observable by the program by performing comparisons against the global's
  address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
  its own copy of the global if it requires one, and the copy in each linkage unit
  must be the same)
- It is a constant or a function (which means that the program cannot observe that
  the unique-address rule has been broken by writing to the global)

Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.

See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.html
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.

Part of the fix for PR27553.

Differential Revision: http://reviews.llvm.org/D20348

llvm-svn: 272709
2016-06-14 21:01:22 +00:00
Nirav Dave f8d00d5cac Fix BSS global handling in AsmPrinter
Change EmitGlobalVariable to check final assembler section is in BSS
before using .lcomm/.comm directive. This prevents globals from being
put into .bss erroneously when -data-sections is used.

This fixes PR26570.

Reviewers: echristo, rafael

Subscribers: llvm-commits, mehdi_amini

Differential Revision: http://reviews.llvm.org/D21146

llvm-svn: 272674
2016-06-14 15:09:30 +00:00
Benjamin Kramer 4ca41fd09e Run clang-tidy's performance-unnecessary-copy-initialization over LLVM.
No functionality change intended.

llvm-svn: 272516
2016-06-12 17:30:47 +00:00
Benjamin Kramer bdc4956bac Pass DebugLoc and SDLoc by const ref.
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.

llvm-svn: 272512
2016-06-12 15:39:02 +00:00
Reid Kleckner 6d1d27542f [codeview] Skip DIGlobalVariables with no variable
They have probably been discarded during optimization.

llvm-svn: 272231
2016-06-09 00:29:00 +00:00
Reid Kleckner de3d8b500f [DebugInfo] Add calling convention support for DWARF and CodeView
Summary:
Now DISubroutineType has a 'cc' field which should be a DW_CC_ enum.  If
it is present and non-zero, the backend will emit it as a
DW_AT_calling_convention attribute. On the CodeView side, we translate
it to the appropriate enum for the LF_PROCEDURE record.

I added a new LLVM vendor specific enum to the list of DWARF calling
conventions. DWARF does not appear to attempt to standardize these, so I
assume it's OK to do this until we coordinate with GCC on how to emit
vectorcall convention functions.

Reviewers: dexonsmith, majnemer, aaboud, amccarth

Subscribers: mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D21114

llvm-svn: 272197
2016-06-08 20:34:29 +00:00
Benjamin Kramer c321e53402 Apply most suggestions of clang-tidy's performance-unnecessary-value-param
Avoids unnecessary copies. All changes audited & pass tests with asan.
No functional change intended.

llvm-svn: 272190
2016-06-08 19:09:22 +00:00
Adrian McCarthy f3c3c13206 Generate codeview for array type metadata.
Differential Revision: http://reviews.llvm.org/D21107

llvm-svn: 272187
2016-06-08 18:22:59 +00:00
Reid Kleckner 6f3406df67 Re-land "[codeview] Emit information about global variables"
This reverts commit r271962 and reinstantes r271957.

MSVC's linker doesn't appear to like it if you have an empty symbol
substream, so only open a symbol substream if we're going to emit
something about globals into it.

Makes check-asan pass.

llvm-svn: 271965
2016-06-07 00:02:03 +00:00
Reid Kleckner e8a236fc2e Revert "[codeview] Emit information about global variables"
This reverts commit r271957, it broke check-asan on Windows.

llvm-svn: 271962
2016-06-06 23:41:38 +00:00
Reid Kleckner 87eddf723d [codeview] Emit information about global variables
This currently emits everything as S_GDATA32, which isn't right for
things like thread locals, but it's a start.

llvm-svn: 271957
2016-06-06 23:23:47 +00:00
David Majnemer 8c46a4ceea [AsmPrinter, CodeView] There are some more ways of getting wchar_t
C++ has a builtin type called wchar_t.  Clang also provides a type
called __wchar_t in C mode.

In C mode, wchar_t can be a typedef to unsigned short.

llvm-svn: 271793
2016-06-04 15:40:33 +00:00
Reid Kleckner a8d5740757 [codeview] Add basic record type translation
This only translates data members for now. Translating overloaded
methods is complicated, so I stopped short of doing that.

Reviewers: aaboud

Differential Revision: http://reviews.llvm.org/D20924

llvm-svn: 271680
2016-06-03 15:58:20 +00:00
David Majnemer b68f32f0cf [CodeView] Use None instead of Void if there is no subprogram
llvm-svn: 271566
2016-06-02 18:51:24 +00:00
Reid Kleckner b9c80fd8b5 [codeview] Fix crash when handling qualified void types
The DIType* for void is the null pointer. A null DIType can never be a
qualified type, so we can just exit the loop at this point and go to
getTypeIndex(BaseTy).

Fixes PR27984

llvm-svn: 271550
2016-06-02 17:40:51 +00:00
David Majnemer 75c3ebfa02 [CodeView] Implement function-type indices
We still need to do something about member functions and calling
conventions.

Differential Revision: http://reviews.llvm.org/D20900

llvm-svn: 271541
2016-06-02 17:13:53 +00:00
David Majnemer 1c2cb1ddd7 [CodeView] Use the right type index for long long
We used T_INT8 instead of T_QUAD.

llvm-svn: 271497
2016-06-02 07:02:32 +00:00
David Majnemer afefa67310 [CodeView] Remove superfluous bitmath
llvm-svn: 271495
2016-06-02 06:21:42 +00:00
David Majnemer d065e23dac [codeview] Return type indices for typedefs
Use the type index of the underlying type unless we have a typedef from
long to HRESULT; HRESULT typedefs are translated to T_HRESULT.

llvm-svn: 271494
2016-06-02 06:21:37 +00:00
Reid Kleckner 846edb6fdc Fix the NDEBUG build
llvm-svn: 271411
2016-06-01 17:31:24 +00:00
Reid Kleckner 5acacbb04f [codeview] Translate basic DITypes to CV type records
Summary:
This is meant to be the tiniest step towards DIType to CV type index
translation that I could come up with. Whenever translation fails, we use type
index zero, which is the unknown type.

Reviewers: aaboud, zturner

Subscribers: llvm-commits, amccarth

Differential Revision: http://reviews.llvm.org/D20840

llvm-svn: 271408
2016-06-01 17:05:51 +00:00
Peter Collingbourne b326986de0 DwarfDebug: Simplify. NFC.
llvm-svn: 271360
2016-06-01 02:58:40 +00:00
Petr Hosek faef3207de [MC] Rename EmitFill to emitFill
This is to match the overloaded variants as well as the new style.

Differential Revision: http://reviews.llvm.org/D20690

llvm-svn: 271359
2016-06-01 01:59:58 +00:00
Reid Kleckner fbdbe9e22b [codeview] Improve readability of type record assembly
Adds the method MCStreamer::EmitBinaryData, which is usually an alias
for EmitBytes. In the MCAsmStreamer case, it is overridden to emit hex
dump output like this:
        .byte   0x0e, 0x00, 0x08, 0x10
        .byte   0x03, 0x00, 0x00, 0x00
        .byte   0x00, 0x00, 0x00, 0x00
        .byte   0x00, 0x10, 0x00, 0x00

Also, when verbose asm comments are enabled, this patch prints the dump
output for each comment before its record, like this:
        # ArgList (0x1000) {
        #   TypeLeafKind: LF_ARGLIST (0x1201)
        #   NumArgs: 0
        #   Arguments [
        #   ]
        # }
        .byte   0x06, 0x00, 0x01, 0x12
        .byte   0x00, 0x00, 0x00, 0x00

This should make debugging easier and testing more convenient.

Reviewers: aaboud

Subscribers: majnemer, zturner, amccarth, aaboud, llvm-commits

Differential Revision: http://reviews.llvm.org/D20711

llvm-svn: 271313
2016-05-31 18:45:36 +00:00
Reid Kleckner 5d122f872d [codeview] Use comdats for debug info describing comdat functions
Summary:
This allows the linker to discard unused symbol information for comdat
functions that were discarded during the link. Before this change,
searching for the name of an inline function in the debugger would
return multiple results, one per symbol subsection in the object file.
After this change, there is only one result, the result for the function
chosen by the linker.

Reviewers: zturner, majnemer

Subscribers: aaboud, amccarth, llvm-commits

Differential Revision: http://reviews.llvm.org/D20642

llvm-svn: 270792
2016-05-25 23:16:12 +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
Reid Kleckner 2280f9325e Modify emitTypeInformation to use MemoryTypeTableBuilder, take 2
This effectively revers commit r270389 and re-lands r270106, but it's
almost a rewrite.

The behavior change in r270106 was that we could no longer assume that
each LF_FUNC_ID record got its own type index. This patch adds a map
from DINode* to TypeIndex, so we can stop making that assumption.

This change also emits padding bytes between type records similar to the
way MSVC does. The size of the type record includes the padding bytes.

llvm-svn: 270485
2016-05-23 20:23:46 +00:00
Zachary Turner a78ecd1e6c [codeview] Refactor symbol records to use same pattern as types.
This will pave the way to introduce a full fledged symbol visitor
similar to how we have a type visitor, thus allowing the same
dumping code to be used in llvm-readobj and llvm-pdbdump.

Differential Revision: http://reviews.llvm.org/D20384
Reviewed By: rnk

llvm-svn: 270475
2016-05-23 18:49:06 +00:00
David Majnemer 6cd7c9185b Revert "Modify emitTypeInformation to use MemoryTypeTableBuilder"
This reverts commit r270106.  It results in certain function types
omitted in the output.

llvm-svn: 270389
2016-05-23 01:37:45 +00:00
Peter Collingbourne 5973bc8a82 CodeGen: Move the call to DwarfDebug::beginModule() out of the constructor.
This gives AsmPrinter a chance to initialize its DD field before
we call beginModule(), which is about to start using it.

Differential Revision: http://reviews.llvm.org/D20413

llvm-svn: 270258
2016-05-20 19:35:35 +00:00
Peter Collingbourne 96c9ae6a20 CodeGen: Do not require a MachineFunction just to create a DIEDwarfExpression.
We are about to start using DIEDwarfExpression to create global variable
DIEs, which happens before we generate code for functions.

Differential Revision: http://reviews.llvm.org/D20412

llvm-svn: 270257
2016-05-20 19:35:17 +00:00
Rafael Espindola 78d947b4f5 Fix pr27728.
Sorry for the lack testcase. There is one in the pr, but it depends on
std::sort and the .ll version is 110 lines, so I don't think it is
wort it.

The bug was that we were sorting after adding a terminator, and the
sorting algorithm could end up putting the terminator in the middle of
the List vector.

With that we would create a Spans map entry keyed on nullptr which would
then be added to CUs and fail in that sorting.

llvm-svn: 270165
2016-05-20 00:38:28 +00:00
Rafael Espindola 0a78f8c463 clang-format. NFC.
llvm-svn: 270156
2016-05-19 23:17:37 +00:00
Adrian McCarthy a972d6121e Modify emitTypeInformation to use MemoryTypeTableBuilder
A baby step toward translating DIType records to CodeView.

This does not (yet) combine the record length with the record data. I'm going back and forth trying to determine if that's a good idea.

llvm-svn: 270106
2016-05-19 20:12:56 +00:00
Zachary Turner 63a2846e84 [codeview] Some cleanup of Symbol Records.
* Reworks the CVSymbolTypes.def to work similarly to TypeRecords.def.
* Moves some enums from SymbolRecords.h to CodeView.h to maintain
  consistency with how we do type records.
* Generalize a few simple things like the record prefix
* Define the leaf enum and the kind enum similar to how we do with tyep
  records.

Differential Revision: http://reviews.llvm.org/D20342
Reviewed By: amccarth, rnk

llvm-svn: 269867
2016-05-17 23:50:21 +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
Adrian Prantl f0a41089ff Debug Info: Don't emit bitfields in the DWARF4 format when tuning for GDB.
As discovered in PR27758, GDB does not fully support the DWARF 4 format.
This patch ensures we always emit bitfields in the DWARF 2 when tuning for GDB.

llvm-svn: 269827
2016-05-17 20:12:08 +00:00
Adrian Prantl 7aa34c8cbb Debug Info: Don't emit a DW_AT_data_member_location for DWARF bitfields.
The DWARF spec states that a member entry may have either a
DW_AT_data_member_location or a DW_AT_data_bit_offset, but not both.

This fixes a bug found in PR 27758.

llvm-svn: 269731
2016-05-17 02:37:53 +00:00
Adrian Prantl e7d833defb Debug info: Don't emit a DW_AT_byte_size when emitting a DWARF4 bit field.
The DWARF spec clearly states that a bit field member should have either a
DW_AT_byte_size or a DW_AT_bit_size, but not both.
Also the DW_AT_byte_size is redundant with the size of the type of the member.

This fixes a bug found in PR 27758.

llvm-svn: 269714
2016-05-16 22:45:10 +00:00
Rafael Espindola e64619ce6e Fail early on unknown appending linkage variables.
In practice only a few well known appending linkage variables work.

Currently if codegen sees an unknown appending linkage variable it will
just print it as a regular global. That is wrong as the symbol in the
produced object file has different semantics as the one provided by the
appending linkage.

This just errors early instead of producing a broken .o.

llvm-svn: 269706
2016-05-16 21:14:24 +00:00
Reid Kleckner 4525fbe22a [codeview] Align class and print names of types
Summary: This way we can get rid of one of the fields in the .def file.

Reviewers: llvm-commits

Subscribers: zturner

Differential Revision: http://reviews.llvm.org/D20251

llvm-svn: 269461
2016-05-13 19:37:07 +00:00
Rafael Espindola 83658d6e7a Return a StringRef from getSection.
This is similar to how getName is handled.

llvm-svn: 269218
2016-05-11 18:21:59 +00:00
Zachary Turner ae3882a19a Refactor CodeView type records to use common code.
Differential Revision: http://reviews.llvm.org/D20138
Reviewed By: rnk

llvm-svn: 269216
2016-05-11 17:47:35 +00:00
Rafael Espindola 610a4e916e Merge two unreachable cases.
llvm-svn: 269189
2016-05-11 14:41:30 +00:00
Adrian Prantl 723ccd2790 Debug Info: Prevent DW_AT_abstract_origin from being emitted twice
for the same subprogram.

This fixes a bug where DW_AT_abstract_origin is being emitted twice for
the same subprogram if a function is both inlined and emitted in the same
translation unit, by restoring the pre-r266446 behavior.

http://reviews.llvm.org/D20072

llvm-svn: 269103
2016-05-10 19:38:51 +00:00
Reid Kleckner 97837b7b09 [MC] Create unique .pdata sections for every .text section
Summary:
This adds a unique ID to the COFF section uniquing map, similar to the
one we have for ELF.  The unique id is not currently exposed via the
assembler because we don't have a use case for it yet. Users generally
create .pdata with the .seh_* family of directives, and the assembler
internally needs to produce .pdata and .xdata sections corresponding to
the code section.

The association between .text sections and the assembler-created .xdata
and .pdata sections is maintained as an ID field of MCSectionCOFF. The
CFI-related sections are created with the given unique ID, so if more
code is added to the same text section, we can find and reuse the CFI
sections that were already created.

Reviewers: majnemer, rafael

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19376

llvm-svn: 268331
2016-05-02 23:22:18 +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
Adrian Prantl e5447574c8 Debug Info: Restore the pre-r240853 behavior for DWARF2 bitfields.
The DWARF2 specification of DW_AT_bit_offset is ambiguous for
little-endian machines, but by restoring to the old behavior
we match what debuggers expect and what other popular compilers
generate.

llvm-svn: 267896
2016-04-28 15:37:52 +00:00
Adrian Prantl f393d313ec Debug info: Support DWARF4 bitfields via DW_AT_data_bit_offset.
The DWARF2 specification of DW_AT_bit_offset was written from the perspective of
a big-endian machine with unclear semantics for other systems.  DWARF4
deprecated DW_AT_bit_offset and introduced a new attribute DW_AT_data_bit_offset
that simply counts the number of bits from the beginning of the containing
entity regardless of endianness.

After this patch LLVM emits DW_AT_bit_offset for DWARF 2 or 3 and
DW_AT_data_bit_offset when DWARF 4 or later is requested.

llvm-svn: 267895
2016-04-28 15:37:48 +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
Peter Collingbourne 265ebd7d70 CodeGen: Use PLT relocations for relative references to unnamed_addr functions.
The relative vtable ABI (PR26723) needs PLT relocations to refer to virtual
functions defined in other DSOs. The unnamed_addr attribute means that the
function's address is not significant, so we're allowed to substitute it
with the address of a PLT entry.

Also includes a bonus feature: addends for COFF image-relative references.

Differential Revision: http://reviews.llvm.org/D17938

llvm-svn: 267211
2016-04-22 20:40:10 +00:00
Amjad Aboud a5ba99140c Fixed Dwarf debug info emission to skip DILexicalBlockFile entries.
Before this fix, DILexicalBlockFile entries were skipped only in some cases and were not in other cases.

Differential Revision: http://reviews.llvm.org/D18724

llvm-svn: 267004
2016-04-21 16:58:49 +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
Reid Kleckner 28865809fe Sink DI metadata usage out of MachineInstr.h and MachineInstrBuilder.h
MachineInstr.h and MachineInstrBuilder.h are very popular headers,
widely included across all LLVM backends. It turns out that there only a
handful of TUs that actually care about DI operands on MachineInstrs.

After this change, touching DebugInfoMetadata.h and rebuilding llc only
needs 112 actions instead of 542.

llvm-svn: 266351
2016-04-14 18:29:59 +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
Adrian Prantl 5992a72b4d Support the Nodebug emission kind for DICompileUnits.
Sample-based profiling and optimization remarks currently remove
DICompileUnits from llvm.dbg.cu to suppress the emission of debug info
from them. This is somewhat of a hack and only borderline legal IR.

This patch uses the recently introduced NoDebug emission kind in
DICompileUnit to achieve the same result without breaking the Verifier.
A nice side-effect of this change is that it is now possible to combine
NoDebug and regular compile units under LTO.

http://reviews.llvm.org/D18808
<rdar://problem/25427165>

llvm-svn: 265861
2016-04-08 22:43:03 +00:00
Adrian Prantl 3e9c88753b DwarfDebug: Support floating point constants in location lists.
This patch closes a gap in the DWARF backend that caused LLVM to drop
debug info for floating point variables that were constant for part of
their scope. Floating point constants are emitted as one or more
DW_OP_constu joined via DW_OP_piece.

This fixes a regression caught by the LLDB testsuite that I introduced
in r262247 when we stopped blindly expanding the range of singular
DBG_VALUEs to span the entire scope and started to emit location lists
with accurate ranges instead.

Also deletes a now-impossible testcase (debug-loc-empty-entries).

<rdar://problem/25448338>

llvm-svn: 265760
2016-04-08 00:38:37 +00:00
Dmitry Polukhin a1feff7024 [GCC] Attribute ifunc support in llvm
This patch add support for GCC attribute((ifunc("resolver"))) for
targets that use ELF as object file format. In general ifunc is a
special kind of function alias with type @gnu_indirect_function. Patch
for Clang http://reviews.llvm.org/D15524

Differential Revision: http://reviews.llvm.org/D15525

llvm-svn: 265667
2016-04-07 12:32:19 +00:00
Dmitry Polukhin a3d5b0b218 [IFUNC] Use GlobalIndirectSymbol when aliases and ifuncs have something similar
Second part extracted from http://reviews.llvm.org/D15525

Use GlobalIndirectSymbol in all cases when aliases and ifuncs have
something in common.

Differential Revision: http://reviews.llvm.org/D18754

llvm-svn: 265382
2016-04-05 08:47:51 +00:00
Adrian Prantl b939a25707 Move the DebugEmissionKind enum from DIBuilder into DICompileUnit.
This mostly cosmetic patch moves the DebugEmissionKind enum from DIBuilder
into DICompileUnit. DIBuilder is not the right place for this enum to live
in — a metadata consumer should not have to include DIBuilder.h.
I also added a Verifier check that checks that the emission kind of a
DICompileUnit is actually legal.

http://reviews.llvm.org/D18612
<rdar://problem/25427165>

llvm-svn: 265077
2016-03-31 23:56:58 +00:00
Tim Shen 800ed436e5 [AsmPrinter] Print aliases in topological order
Print aliases in topological order, that is, for any alias a = b,
b must be printed before a. This is because on some targets (e.g. PowerPC)
linker expects aliases in such an order to generate correct TOC information.

GCC also prints aliases in topological order.

llvm-svn: 265064
2016-03-31 22:08:19 +00:00
Reid Kleckner f6f04f8fc8 Consider regmasks when computing register-based DBG_VALUE live ranges
Now register parameters that aren't saved to the stack or CSRs are
considered dead after the first call. Previously the debugger would show
whatever was in the register.

Fixes PR26589

Reviewers: aprantl

Differential Revision: http://reviews.llvm.org/D17211

llvm-svn: 264429
2016-03-25 17:54:46 +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
David Blaikie 0b214e4a2a [debuginfo] Include dwo_name in the split unit to improve dwp diagnostics
When multiple DWP files are merged together and duplicate DWO IDs are
found it's currently difficult to give an actionable error message - the
DW_AT_name of the CU could be provided, but might be identical (if the
same source file is built into two different configurations), which
doesn't help the user identify the problem.

When no intermediate DWP files are generated, the path to the two DWO
files could be provided - but is lost once the DWOs are merged into a
DWP.

So, include the name of the DWO (dwo_name) in the split file so that
collissions involving a source CU from a DWP can be better diagnosed.

(improvements to llvm-dwp using this to come shortly)

llvm-svn: 264316
2016-03-24 18:37:08 +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
Craig Topper ea87eae4ca Suppress a -Wunused-variable warning in release builds.
llvm-svn: 263892
2016-03-20 01:17:54 +00:00
Reid Kleckner fbd7787d7e [codeview] Only emit function ids for inlined functions
We aren't referencing any other kind of function currently.
Should save a bit on our debug info size.

llvm-svn: 263817
2016-03-18 18:54:32 +00:00
Peter Collingbourne a1f8625662 DebugInfo: Add ability to not emit DW_AT_vtable_elem_location for virtual functions.
A virtual index of -1u indicates that the subprogram's virtual index is
unrepresentable (for example, when using the relative vtable ABI), so do
not emit a DW_AT_vtable_elem_location attribute for it.

Differential Revision: http://reviews.llvm.org/D18236

llvm-svn: 263765
2016-03-17 23:58:03 +00:00
Lang Hames 1b640e05ba [MachO] Add MachO alt-entry directive support.
This patch adds support for the MachO .alt_entry assembly directive, and uses
it for global aliases with non-zero GEP offsets. The alt_entry flag indicates
that a symbol should be layed out immediately after the preceding symbol.
Conceptually it introduces an alternate entry point for a function or data
structure. E.g.:

safe_foo:
  // check preconditions for foo
.alt_entry fast_foo
fast_foo:
  // body of foo, can assume preconditions.

The .alt_entry flag is also implicitly set on assembly aliases of the form:

a = b + C

where C is a non-zero constant, since these have the same effect as an
alt_entry symbol: they introduce a label that cannot be moved relative to the
preceding one. Setting the alt_entry flag on aliases of this form fixes
http://llvm.org/PR25381.

llvm-svn: 263521
2016-03-15 01:43:05 +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
David Majnemer b9456a5eb3 [CodeView] Consistently handle overly large symbol names
Overly large symbol names weren't correctly handled for leaf function
records.

llvm-svn: 263408
2016-03-14 05:15:09 +00:00
David Majnemer 1256125fb7 [CodeView] Truncate display names
Fundamentally, the length of a variable or function name is bound by the
maximum size of a record: 0xffff.  However, the name doesn't live in a
vacuum; other data is associated with the name, lowering the bound
further.

We would naively attempt to emit the name, causing us to assert because
the record would no-longer fit in 16-bits.  Instead, truncate the name
but preserve as much as we can.

While I have tested this locally, I've decided to not commit it due to
the test's size.

N.B.  While this behavior is undesirable, it is better than MSVC's
behavior.  They seem to truncate to ~4000 characters.

llvm-svn: 263378
2016-03-13 10:53:30 +00:00
Pete Cooper adebb9379a Remove llvm::getDISubprogram in favor of Function::getSubprogram
llvm::getDISubprogram walks the instructions in a function, looking for one in the scope of the current function, so that it can find the !dbg entry for the subprogram itself.

Now that !dbg is attached to functions, this should not be necessary. This patch changes all uses to just query the subprogram directly on the function.

Ideally this should be NFC, but in reality its possible that a function:

has no !dbg (in which case there's likely a bug somewhere in an opt pass), or
that none of the instructions had a scope referencing the function, so we used to not find the !dbg on the function but now we will

Reviewed by Duncan Exon Smith.

Differential Revision: http://reviews.llvm.org/D18074

llvm-svn: 263184
2016-03-11 02:14:16 +00:00
Benjamin Kramer 4dbf3371bb Make headers self-contained again.
llvm-svn: 262702
2016-03-04 10:49:30 +00:00
David Majnemer cb305dea1c [WinEH] Allocate the registration node before the catch objects
The CatchObjOffset is relative to the end of the EH registration node
for 32-bit x86 WinEH targets.  A special sentinel value, 0, is used to
indicate that no catch object should be initialized.

This means that a catch object allocated immediately before the
registration node would be assigned a CatchObjOffset of 0, leading the
runtime to believe that a catch object should not be initialized.

To handle this, allocate the registration node prior to any other frame
object.  This will ensure that catch objects will not be allocated
before the registration node.

This fixes PR26757.

Differential Revision: http://reviews.llvm.org/D17689

llvm-svn: 262294
2016-03-01 04:30:16 +00:00
Adrian Prantl dba58fbdd9 Improve the debug output of DwarfDebug::buildLocationList().
llvm-svn: 262265
2016-02-29 22:28:22 +00:00
Adrian Prantl fb2add2be1 Fix PR26585 by improving the promotion of DBG_VALUEs to DW_AT_locations.
When a variable is described by a single DBG_VALUE instruction we can
often use a more efficient inline DW_AT_location instead of using a
location list.

This commit makes the heuristic that decides when to apply this
optimization stricter by also verifying that the DBG_VALUE is live at the
entry of the function (instead of just checking that it is valid until
the end of the function).

<rdar://problem/24611008>

llvm-svn: 262247
2016-02-29 19:49:46 +00:00
Adrian Prantl 693e8de0fa fix typo in comment
llvm-svn: 262236
2016-02-29 17:06:46 +00:00
Duncan P. N. Exon Smith fd8cc23220 CodeGen: Change MachineInstr to use MachineInstr&, NFC
Change MachineInstr API to prefer MachineInstr& over MachineInstr*
whenever the parameter is expected to be non-null.  Slowly inching
toward being able to fix PR26753.

llvm-svn: 262149
2016-02-27 20:01:33 +00:00
Duncan P. N. Exon Smith f9ab416d70 WIP: CodeGen: Use MachineInstr& in MachineInstrBundle.h, NFC
Update APIs in MachineInstrBundle.h to take and return MachineInstr&
instead of MachineInstr* when the instruction cannot be null.  Besides
being a nice cleanup, this is tacking toward a fix for PR26753.

llvm-svn: 262141
2016-02-27 17:05:33 +00:00
Amaury Sechet b2055c53ba Fix warning in DwarfCFIException. NFC
llvm-svn: 262061
2016-02-26 20:49:07 +00:00
Amaury Sechet 7067ad3c27 Extract the method to begin and end a fragment in AsmPrinterHandler in their own method. NFC
Summary: This is extracted from D17555

Reviewers: davidxl, reames, sanjoy, MatzeB, pete

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D17580

llvm-svn: 262058
2016-02-26 20:30:37 +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
David Majnemer a3ea407d48 [X86] Use the correct alignment for COMDAT constant pool entries
COFF doesn't have sections with mergeable contents.  Instead, each
constant pool entry ends up in a COMDAT section.  The linker, when
choosing between COMDAT sections, doesn't choose the max alignment of
the two sections.  You just get whatever alignment was on the section.

If one constant needed a higher alignment in one object file from
another one, then we will get into trouble if the linker chooses the
lower alignment one.

Instead, lets promote the alignment of the constant pool entry to make
sure we don't use an under aligned constant with an instruction which
assumed otherwise.

This fixes PR26680.

llvm-svn: 261462
2016-02-21 01:30:30 +00:00
Benjamin Kramer 3a16e2a26a Make header self-contained. NFC.
llvm-svn: 261234
2016-02-18 18:02:48 +00:00
Adrian Prantl 3b89e6634c DwarfDebug: Don't drop the DIExpression just because a variable is
described by an immediate.

Found via http://reviews.llvm.org/D16867
Thanks to Paul Robinson for pointing this out.

<rdar://problem/24456528>

llvm-svn: 261168
2016-02-17 22:20:08 +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
Reid Kleckner 9a593ee7d2 [codeview] Bail on a DBG_VALUE register operand with no register
This apparently comes up when the register allocator decides that a
variable will become undef along a certain path.

Also improve the error message we emit when we can't map from LLVM
register number to CV register number.

llvm-svn: 261016
2016-02-16 21:49:26 +00:00
Reid Kleckner 6e0d5f573c [codeview] Fix assertion on non-memory, non-register DBG_VALUE instructions
Eventually we should find a way to describe constant variables, but it
is not obvious how to do this at the moment.

llvm-svn: 261010
2016-02-16 21:14:51 +00:00
Aaron Ballman c6a2f2140b A signed bitfield's range is [-1,0], so assigning 1 is technically an overflow. However, the other bitfield requires a signed value (it supports negative offsets), so it is slightly better to retain a signed 1-bit bitfield and use -1 instead of 1. Silences an MSVC warning.
llvm-svn: 260973
2016-02-16 15:35:51 +00:00
Reid Kleckner 876330d53a [codeview] Describe local variables in registers
llvm-svn: 260746
2016-02-12 21:48:30 +00:00