Add the IR and the AsmPrinter parts for handling of the DW_OP_entry_values
DWARF operation.
([11/13] Introduce the debug entry values.)
Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>
Differential Revision: https://reviews.llvm.org/D60866
llvm-svn: 364542
A unique DISubprogram may be attached to a function declaration used for
call site debug info.
([6/13] Introduce the debug entry values.)
Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>
Differential Revision: https://reviews.llvm.org/D60713
llvm-svn: 364500
Avoids using a plain unsigned for registers throughoug codegen.
Doesn't attempt to change every register use, just something a little
more than the set needed to build after changing the return type of
MachineOperand::getReg().
llvm-svn: 364191
The goal is to improve hwasan's error reporting for stack use-after-return by
recording enough information to allow the specific variable that was accessed
to be identified based on the pointer's tag. Currently we record the PC and
lower bits of SP for each stack frame we create (which will eventually be
enough to derive the base tag used by the stack frame) but that's not enough
to determine the specific tag for each variable, which is the stack frame's
base tag XOR a value (the "tag offset") that is unique for each variable in
a function.
In IR, the tag offset is most naturally represented as part of a location
expression on the llvm.dbg.declare instruction. However, the presence of the
tag offset in the variable's actual location expression is likely to confuse
debuggers which won't know about tag offsets, and moreover the tag offset
is not required for a debugger to determine the location of the variable on
the stack, so at the DWARF level it is represented as an attribute so that
it will be ignored by debuggers that don't know about it.
Differential Revision: https://reviews.llvm.org/D63119
llvm-svn: 363635
This is consistent with GCC's behavior (which is the defacto standard
for pubnames). Though I find the presence of enumerators from enum
classes to be a bit confusing, possibly a bug on GCC's end (since they
can't be named unqualified, unlike the other names - and names nested in
classes don't go in pubnames, for instance - presumably because one must
name the class first & that's enough to limit the scope of the search)
llvm-svn: 363349
Summary:
Before it was using the fully qualified name only for static data members.
Now it does for all variable names to match MSVC.
Reviewers: rnk
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63012
llvm-svn: 363335
Since the DebugLocEntry::Value is used as part of DwarfDebug and
DebugLocEntry make it as the separate class.
Reviewers: aprantl, dstenb
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D63213
llvm-svn: 363246
We aim to ignore changes in variable locations during the prologue and
epilogue of functions, to avoid using space documenting location changes
that aren't visible. However in D61940 / r362951 this got ripped out as
the previous implementation was unsound.
Instead, use the FrameDestroy flag to identify when we're in the epilogue
of a function, and ignore variable location changes accordingly. This fits
in with existing code that examines the FrameSetup flag.
Some variable locations get shuffled in modified tests as they now cover
greater ranges, which is what would be expected. Some additional
single-location variables are generated too. Two tests are un-xfailed,
they were only xfailed due to r362951 deleting functionality they depended
on.
Apparently some out-of-tree backends don't accurately maintain FrameDestroy
flags -- if you're an out-of-tree maintainer and see changes in variable
locations disappear due to a faulty FrameDestroy flag, it's safe to back
this change out. The impact is just slightly more debug info than necessary.
Differential Revision: https://reviews.llvm.org/D62314
llvm-svn: 363245
This commit reapplies r359426 (which was reverted in r360301 due to
performance problems) and rolls in D61940 to address the performance problem.
I've combined the two to avoid creating a span of slow-performance, and to
ease reverting if more problems crop up.
The summary of D61940: This patch removes the "ChangingRegs" facility in
DbgEntityHistoryCalculator, as its overapproximate nature can produce incorrect
variable locations. An unchanging register doesn't mean a variable doesn't
change its location.
The patch kills off everything that calculates the ChangingRegs vector.
Previously ChangingRegs spotted epilogues and marked registers as unchanging if
they weren't modified outside the epilogue, increasing the chance that we can
emit a single-location variable record. Without this feature,
debug-loc-offset.mir and pr19307.mir become temporarily XFAIL. They'll be
re-enabled by D62314, using the FrameDestroy flag to identify epilogues, I've
split this into two steps as FrameDestroy isn't necessarily supported by all
backends.
The logic for terminating variable locations at the end of a basic block now
becomes much more enjoyably simple: we just terminate them all.
Other test changes: inlined-argument.ll becomes XFAIL, but for a longer term.
The current algorithm for detecting that a variable has a single-location
doesn't work in this scenario (inlined function in multiple blocks), only other
bugs were making this test work. fission-ranges.ll gets slightly refreshed too,
as the location of "p" is now correctly determined to be a single location.
Differential Revision: https://reviews.llvm.org/D61940
llvm-svn: 362951
Variable's stack location can stretch longer than it should. If a
variable is placed at the stack in a some nested basic block its range
can be calculated to be up to the next occurrence of the variable's
DBG_VALUE, or up to the end of the function, thus covering a basic
blocks that should not be included in the variable’s location range.
This happens because the DbgEntityHistoryCalculator ends register
locations at the end of a basic block only if the variable’s location
register has been changed throughout the function, which is not the
case for the register used to reference stack objects.
This patch also tries to produce a single value location if the location
list builder managed to merge all the locations into one.
Reviewers: aprantl, dstenb, jmorse
Reviewed By: aprantl, dstenb, jmorse
Subscribers: djtodoro, ivanbaev, asowda
Tags: #debug-info
Differential Revision: https://reviews.llvm.org/D61600
llvm-svn: 362923
Separate the remark serialization to YAML from the LLVM Diagnostics.
This adds a new serialization abstraction: remarks::Serializer. It's
completely independent from lib/IR and it provides an easy way to
replace YAML by providing a new remarks::Serializer.
Differential Revision: https://reviews.llvm.org/D62632
llvm-svn: 362160
Summary:
Add static data members to IR debug info's list of global variables
so that they are emitted as S_CONSTANT records.
Related to https://bugs.llvm.org/show_bug.cgi?id=41615.
Reviewers: rnk
Subscribers: aprantl, cfe-commits, llvm-commits, thakis
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D62167
llvm-svn: 362038
Summary:
When DwarfDebug::buildLocationList() encountered an undef debug value,
it would truncate all open values, regardless if they were overlapping or
not. This patch fixes so that it only does that for overlapping fragments.
This change unearthed a bug that I had introduced in D57511,
which I have fixed in this patch. The code in DebugHandlerBase that
changes labels for parameter debug values could break DwarfDebug's
assumption that the labels for the entries in the debug value history
are monotonically increasing. Before this patch, that bug could result
in location list entries whose ending address was lower than the
beginning address, and with the changes for undef debug values that this
patch introduces it could trigger an assertion, due to attempting to
emit location list entries with empty ranges. A reproducer for the bug
is added in param-reg-const-mix.mir.
Reviewers: aprantl, jmorse, probinson
Reviewed By: aprantl
Subscribers: javed.absar, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D62379
llvm-svn: 361820
When printing assembly for PtrToInt, AsmPrinter::lowerConstant
incorrectly assumed that if PtrToInt was not converting to an
int with exactly the same number of bits, it must be widening
to a larger int. But this isn't necessarily true; PtrToInt can
also shrink the size, which is useful when you want to produce
a known 32-bit pointer on a 64-bit platform (on x86_64 ELF
this yields a R_X86_64_32 relocation).
The old behavior of falling through to the widening case for a
narrowing PtrToInt yields bogus assembly code like this, which
fails to assemble because the no-op bit and it accidentally
creates is not a valid relocation:
```
.long a&-1
```
The fix is to treat a narrowing PtrToInt exactly the same as
it already treats Trunc: just emit the expression and let
the assembler deal with truncating it in the appropriate way.
Patch by Mat Hostetter <mjh@fb.com>.
Differential Revision: https://reviews.llvm.org/D61325
llvm-svn: 361508
Refactor location description kind in order to be easier for extensions
(needed for D60866).
In addition, cut off some bits from the other class fields.
Patch by Djordje Todorovic.
Differential Revision: https://reviews.llvm.org/D62002
llvm-svn: 361480
Summary:
This emits S_CONSTANT records for global variables.
Currently this emits records for the global variables already being tracked in the
LLVM IR metadata, which are just constant global variables; we'll also want S_CONSTANTs
for static data members and enums.
Related to https://bugs.llvm.org/show_bug.cgi?id=41615
Reviewers: rnk
Subscribers: aprantl, hiraditya, llvm-commits, thakis
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61926
llvm-svn: 360948
Before this change, they were erroneously constructed with the EH_LABEL
SDNode opcode, which caused other passes to interact with them in
incorrect ways. See the FIXME about fastisel that this addresses in the
existing test case.
Fixes PR41890
llvm-svn: 360818
The 3-field form was introduced by D3499 in 2014 and the legacy 2-field
form was planned to be removed in LLVM 4.0
For the textual format, this patch migrates the existing 2-field form to
use the 3-field form and deletes the compatibility code.
test/Verifier/global-ctors-2.ll checks we have a friendly error message.
For bitcode, lib/IR/AutoUpgrade UpgradeGlobalVariables will upgrade the
2-field form (add i8* null as the third field).
Reviewed By: rnk, dexonsmith
Differential Revision: https://reviews.llvm.org/D61547
llvm-svn: 360742
The condition !AddrPool.empty() is tested before attachRangesOrLowHighPC(), which may add an entry to AddrPool. We emit DW_AT_low_pc (DW_FORM_addrx) but may incorrectly omit DW_AT_addr_base for LineTablesOnly. This can be easily reproduced:
clang -gdwarf-5 -gmlt -c a.cc
Fix this by moving !AddrPool.empty() below.
This was discovered while investigating an lld crash (fixed by D61889) on such object files: ld.lld --gdb-index a.o
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D61891
llvm-svn: 360678
Follow up to r359122, after a bug was reported in it - the original
change too aggressively tried to move related types out of type units,
which included unnamed types (like array types) which can't reasonably
be declared-but-not-defined.
A step beyond that is that some types in type units can be anonymous, if
they are types with a name for linkage purposes (eg: "typedef struct { }
x;"). So ensure those don't get turned into plain declarations (without
signatures) because, lacking names, they can't be resolved to the
definition.
[Also include a fix for llvm-dwarfdump/libDebugInfoDWARF to pretty print
types in type units]
llvm-svn: 360458
as it was causing significant compile time regressions.
This reverts commit r359426 while we come up with testcases and additional ideas.
llvm-svn: 360301
DWARF5, 2.12 20ff says that
Any debugging information entry representing a pointer or reference
type [may have a DW_AT_address_class attribute].
The existing code (https://reviews.llvm.org/D29670) seems to take a
quite literal interpretation of that wording. I don't see a reason why
an rvalue reference isn't a reference type in the spirit of that
paragraph. This patch allows rvalue references to also have address
spaces.
rdar://problem/50511483
Differential Revision: https://reviews.llvm.org/D61625
llvm-svn: 360176
TypedDINodeRef<T> is a redundant wrapper of Metadata * that is actually a T *.
Accordingly, change DI{Node,Scope,Type}Ref uses to DI{Node,Scope,Type} * or their const variants.
This allows us to delete many resolve() calls that clutter the code.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D61369
llvm-svn: 360108
Summary:
When there are multiple instances of a forward decl record type, only the first one is emitted with a type index, because
the type is added to a map with a null type index. Avoid this by reordering so that forward decl types aren't added to the map.
Reviewers: rnk
Subscribers: aprantl, hiraditya, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61460
llvm-svn: 360101
The primary fix here is to WinException.cpp: we need to exclude jump
tables when computing the length of a function, or else we fail to
correctly compute the length. (We can only compute the number of bytes
consumed by certain assembler directives after the entire file is
parsed. ".p2align" is one of those directives, and is used by jump table
generation.)
The secondary fix, to MCWin64EH, is to make sure we don't silently
miscompile if we hit a similar situation in the future.
It's possible we could extend ARM64EmitUnwindInfo so it allows function
bodies that contain assembler directives, but that's a lot more
complicated; see the FIXME in MCWin64EH.cpp.
Fixes https://bugs.llvm.org/show_bug.cgi?id=41581 .
Differential Revision: https://reviews.llvm.org/D61095
llvm-svn: 359849
The PrologEpilogInserter need to insert a DW_OP_deref_size before
prepending a memory location expression to an already implicit
expression to avoid having the existing expression act on the memory
address instead of the value behind it.
The reason for using DW_OP_deref_size and not plain DW_OP_deref is that
big-endian targets need to read the right size as simply truncating a
larger read would yield the wrong result (LSB bytes are not at the lower
address).
This re-commit fixes issues reported in the first one. Namely deref was
inserted under wrong conditions and additionally the deref_size argument
was incorrectly encoded.
Differential Revision: https://reviews.llvm.org/D59687
llvm-svn: 359535
This patch fixes PR40795, where constant-valued variable locations can
"leak" into blocks placed at higher addresses. The root of this is that
DbgEntityHistoryCalculator terminates all register variable locations at
the end of each block, but not constant-value variable locations.
Fixing this requires constant-valued DBG_VALUE instructions to be
broadcast into all blocks where the variable location remains valid, as
documented in the LiveDebugValues section of SourceLevelDebugging.rst,
and correct termination in DbgEntityHistoryCalculator.
Differential Revision: https://reviews.llvm.org/D59431
llvm-svn: 359426
Summary:
Targets like ARM, MSP430, PPC, and SystemZ have complex behavior when
printing the address of a MachineOperand::MO_GlobalAddress. Move that
handling into a new overriden method in each base class. A virtual
method was added to the base class for handling the generic case.
Refactors a few subclasses to support the target independent %a, %c, and
%n.
The patch also contains small cleanups for AVRAsmPrinter and
SystemZAsmPrinter.
It seems that NVPTXTargetLowering is possibly missing some logic to
transform GlobalAddressSDNodes for
TargetLowering::LowerAsmOperandForConstraint to handle with "i" extended
inline assembly asm constraints.
Fixes:
- https://bugs.llvm.org/show_bug.cgi?id=41402
- https://github.com/ClangBuiltLinux/linux/issues/449
Reviewers: echristo, void
Reviewed By: void
Subscribers: void, craig.topper, jholewinski, dschuff, jyknight, dylanmckay, sdardis, nemanjai, javed.absar, sbc100, jgravelle-google, eraman, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, jrtc27, atanasyan, jsji, llvm-commits, kees, tpimh, nathanchance, peter.smith, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60887
llvm-svn: 359337
Summary:
This emits labels around heapallocsite calls and S_HEAPALLOCSITE debug
info in codeview. Currently only changes FastISel, so emitting labels still
needs to be implemented in SelectionDAG.
Reviewers: rnk
Subscribers: aprantl, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D61083
llvm-svn: 359149
While this doesn't come up in reasonable cases currently (the only user
defined types not in type units are ones without linkage - which makes
for near-ODR violations, because it'd be a type with linkage referencing
a type without linkage - such a type can't be validly defined in more
than one TU, so arguably it shouldn't be in a type unit to begin with -
but it's a convenient way to demonstrate an issue that will become more
revalent with homed modular debug info type definitions - which also
don't need to be in type units but more legitimately so).
Precursor to the Clang change to de-type-unit (by omitting the
'identifier') types homed due to strong linkage vtables. (making that
change without this one would lead to major type duplication in type
units)
llvm-svn: 359122
* Add support for uniquing strings in the remark streamer and emitting the string table in the remarks section.
* Add parsing support for the string table in the RemarkParser.
From this remark:
```
--- !Missed
Pass: inline
Name: NoDefinition
DebugLoc: { File: 'test-suite/SingleSource/UnitTests/2002-04-17-PrintfChar.c',
Line: 7, Column: 3 }
Function: printArgsNoRet
Args:
- Callee: printf
- String: ' will not be inlined into '
- Caller: printArgsNoRet
DebugLoc: { File: 'test-suite/SingleSource/UnitTests/2002-04-17-PrintfChar.c',
Line: 6, Column: 0 }
- String: ' because its definition is unavailable'
...
```
to:
```
--- !Missed
Pass: 0
Name: 1
DebugLoc: { File: 3, Line: 7, Column: 3 }
Function: 2
Args:
- Callee: 4
- String: 5
- Caller: 2
DebugLoc: { File: 3, Line: 6, Column: 0 }
- String: 6
...
```
And the string table in the .remarks/__remarks section containing:
```
inline\0NoDefinition\0printArgsNoRet\0
test-suite/SingleSource/UnitTests/2002-04-17-PrintfChar.c\0printf\0
will not be inlined into \0 because its definition is unavailable\0
```
This is mostly supposed to be used for testing purposes, but it gives us
a 2x reduction in the remark size, and is an incremental change for the
updates to the remarks file format.
Differential Revision: https://reviews.llvm.org/D60227
llvm-svn: 359050
Originally committed in r358931
Reverted in r358997
Seems this change made Apple accelerator tables miss names (because
names started respecting the CU NameTableKind GNU & assuming that
shouldn't produce accelerated names too), which is never correct (apple
accelerator tables don't have separators or CU lists - if present, they
must describe all names in all CUs).
Original Description:
Currently to opt in to debug_names in DWARFv5, the IR must contain
'nameTableKind: Default' which also enables debug_pubnames.
Instead, only allow one of {debug_names, apple_names, debug_pubnames,
debug_gnu_pubnames}.
nameTableKind: Default gives debug_names in DWARFv5 and greater,
debug_pubnames in v4 and earlier - and apple_names when tuning for lldb
on MachO.
nameTableKind: GNU always gives gnu_pubnames
llvm-svn: 359026
Currently to opt in to debug_names in DWARFv5, the IR must contain
'nameTableKind: Default' which also enables debug_pubnames.
Instead, only allow one of {debug_names, apple_names, debug_pubnames,
debug_gnu_pubnames}.
nameTableKind: Default gives debug_names in DWARFv5 and greater,
debug_pubnames in v4 and earlier - and apple_names when tuning for lldb
on MachO.
nameTableKind: GNU always gives gnu_pubnames
llvm-svn: 358931
Summary:
This emits labels around heapallocsite calls and S_HEAPALLOCSITE debug
info in codeview. Currently only changes FastISel, so emitting labels still
needs to be implemented in SelectionDAG.
Reviewers: hans, rnk
Subscribers: aprantl, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D60800
llvm-svn: 358783
Another attempt to land the changes in debug line header to prevent duplicate
files in Dwarf 5. I rolled back my previous commit because of a mistake in
generating the object file in a test. Meanwhile, I addressed some offline
comments and changed the implementation; the largest difference is that
MCDwarfLineTableHeader does not keep DwarfVersion but gets it as a parameter. I
also merged the patch to fix two lld tests that will strt to fail into this
patch.
Original Commit:
https://reviews.llvm.org/D59515
Original Message:
Motivation: In previous dwarf versions, file name indexes started from 1, and
the primary source file was not explicit. Dwarf 5 standard (6.2.4) prescribes
the primary source file to be explicitly given an entry with an index number 0.
The current implementation honors the specification by just duplicating the
main source file, once with index number 0, and later maybe with another
index number. While this is compliant with the letter of the standard, the
duplication causes problems for consumers of this information such as lldb.
(Some files are duplicated, where only some of them have a line table although
all refer to the same file)
With this change, dwarf 5 debug line section files always start from 0, and
the zeroth entry is not duplicated whenever possible. This requires different
handling of dwarf 4 and dwarf 5 during generation (e.g. when a function returns
an index zero for a file name, it signals an error in dwarf 4, but not in dwarf
5) However, I think the minor complication is worth it, because it enables all
consumers (lldb, gdb, dwarfdump, objdump, and so on) to treat all files in the
file name list homogenously.
llvm-svn: 358732
Summary:
X86 is quite complicated; so I intend to leave it as is. ARM+Aarch64 do
basically the same thing (Aarch64 did not correctly handle immediates,
ARM has a test llvm/test/CodeGen/ARM/2009-04-06-AsmModifier.ll that uses
%a with an immediate) for a flag that should be target independent
anyways.
Reviewers: echristo, peter.smith
Reviewed By: echristo
Subscribers: javed.absar, eraman, kristof.beyls, hiraditya, llvm-commits, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60841
llvm-svn: 358618
Summary:
None of these derived classes do anything that the base class cannot.
If we remove these case statements, then the base class can handle them
just fine.
Reviewers: peter.smith, echristo
Reviewed By: echristo
Subscribers: nemanjai, javed.absar, eraman, kristof.beyls, hiraditya, kbarton, jsji, llvm-commits, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60803
llvm-svn: 358603
It causes clang to crash while building Chromium. See https://crbug.com/952230
for reproducer.
> The PrologEpilogInserter need to insert a DW_OP_deref_size before
> prepending a memory location expression to an already implicit
> expression to avoid having the existing expression act on the memory
> address instead of the value behind it.
>
> The reason for using DW_OP_deref_size and not plain DW_OP_deref is that
> big-endian targets need to read the right size as simply truncating a
> larger read would yield the wrong result (LSB bytes are not at the lower
> address).
>
> Differential Revision: https://reviews.llvm.org/D59687
llvm-svn: 358281
The PrologEpilogInserter need to insert a DW_OP_deref_size before
prepending a memory location expression to an already implicit
expression to avoid having the existing expression act on the memory
address instead of the value behind it.
The reason for using DW_OP_deref_size and not plain DW_OP_deref is that
big-endian targets need to read the right size as simply truncating a
larger read would yield the wrong result (LSB bytes are not at the lower
address).
Differential Revision: https://reviews.llvm.org/D59687
llvm-svn: 358268
Because of gp = sdata_start_address + 0x800, gp with signed twelve-bit offset
could covert most of the small data section. Linker relaxation could transfer
the multiple data accessing instructions to a gp base with signed twelve-bit
offset instruction.
Differential Revision: https://reviews.llvm.org/D57493
llvm-svn: 358150
Summary:
The InlineAsm::AsmDialect is only required for X86; no architecture
makes use of it and as such it gets passed around between arch-specific
and general code while being unused for all architectures but X86.
Since the AsmDialect is queried from a MachineInstr, which we also pass
around, remove the additional AsmDialect parameter and query for it deep
in the X86AsmPrinter only when needed/as late as possible.
This refactor should help later planned refactors to AsmPrinter, as this
difference in the X86AsmPrinter makes it harder to make AsmPrinter more
generic.
Reviewers: craig.topper
Subscribers: jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, eraman, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, llvm-commits, peter.smith, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60488
llvm-svn: 358101
Summary:
When calculating the debug value history, DbgEntityHistoryCalculator
would only keep track of register clobbering for the latest debug value
per inlined entity. This meant that preceding register-described debug
value fragments would live on until the next overlapping debug value,
ignoring any potential clobbering. This patch amends
DbgEntityHistoryCalculator so that it keeps track of all registers that
a inlined entity's currently live debug values are described by.
The DebugInfo/COFF/pieces.ll test case has had to be changed since
previously a register-described fragment would incorrectly outlive its
basic block.
The parent patch D59941 is expected to increase the coverage slightly,
as it makes sure that location list entries are inserted after clobbered
fragments, and this patch is expected to decrease it, as it stops
preceding register-described from living longer than they should. All in
all, this patch and the preceding patch has a negligible effect on the
output from `llvm-dwarfdump -statistics' for a clang-3.4 binary built
using the RelWithDebInfo build profile. "Scope bytes covered" increases
by 0.5%, and "variables with location" increases from 2212083 to
2212088, but it should improve the accuracy quite a bit.
This fixes PR40283.
Reviewers: aprantl, probinson, dblaikie, rnk, bjope
Reviewed By: aprantl
Subscribers: llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D59942
llvm-svn: 358073
Summary:
Currently the DbgValueHistorymap only keeps track of clobbered registers
for the last debug value that it has encountered. This could lead to
preceding register-described debug values living on longer in the
location lists than they should. See PR40283 for an example. This
patch does not introduce tracking of multiple registers, but changes
the DbgValueHistoryMap structure to allow for that in a follow-up
patch. This patch is not NFC, as it at least fixes two bugs in
DwarfDebug (both are covered in the new clobbered-fragments.mir test):
* If a debug value was clobbered (its End pointer set), the value would
still be added to OpenRanges, meaning that the succeeding location list
entries could potentially contain stale values.
* If a debug value was clobbered, and there were non-overlapping
fragments that were still live after the clobbering, DwarfDebug would
not create a location list entry starting directly after the
clobbering instruction. This meant that the location list could have
a gap until the next debug value for the variable was encountered.
Before this patch, the history map was represented by <Begin, End>
pairs, where a new pair was created for each new debug value. When
dealing with partially overlapping register-described debug values, such
as in the following example:
DBG_VALUE $reg2, $noreg, !1, !DIExpression(DW_OP_LLVM_fragment, 32, 32)
[...]
DBG_VALUE $reg3, $noreg, !1, !DIExpression(DW_OP_LLVM_fragment, 64, 32)
[...]
$reg2 = insn1
[...]
$reg3 = insn2
the history map would then contain the entries `[<DV1, insn1>, [<DV2, insn2>]`.
This would leave it up to the users of the map to be aware of
the relative order of the instructions, which e.g. could make
DwarfDebug::buildLocationList() needlessly complex. Instead, this patch
makes the history map structure monotonically increasing by dropping the
End pointer, and replacing that with explicit clobbering entries in the
vector. Each debug value has an "end index", which if set, points to the
entry in the vector that ends the debug value. The ending entry can
either be an overlapping debug value, or an instruction which clobbers
the register that the debug value is described by. The ending entry's
instruction can thus either be excluded or included in the debug value's
range. If the end index is not set, the debug value that the entry
introduces is valid until the end of the function.
Changes to test cases:
* DebugInfo/X86/pieces-3.ll: The range of the first DBG_VALUE, which
describes that the fragment (0, 64) is located in RDI, was
incorrectly ended by the clobbering of RAX, which the second
(non-overlapping) DBG_VALUE was described by. With this patch we
get a second entry that only describes RDI after that clobbering.
* DebugInfo/ARM/partial-subreg.ll: This test seems to indiciate a bug
in LiveDebugValues that is caused by it not being aware of fragments.
I have added some comments in the test case about that. Also, before
this patch DwarfDebug would incorrectly include a register-described
debug value from a preceding block in a location list entry.
Reviewers: aprantl, probinson, dblaikie, rnk, bjope
Reviewed By: aprantl
Subscribers: javed.absar, kristof.beyls, jdoerfert, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D59941
llvm-svn: 358072
Summary:
In an upcoming commit the history map will be changed so that it
contains explicit entries for instructions that clobber preceding debug
values, rather than Begin- End range pairs, so generalize the name to
"Entry".
Also, prefix the iterator variable names in buildLocationList() with
"E". In an upcoming commit the entry will have query functions such as
"isD(e)b(u)gValue", which could at a glance make one confuse it for
iterations over MachineInstrs, so make the iterator names a bit more
distinct to avoid that.
Reviewers: aprantl
Reviewed By: aprantl
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59939
llvm-svn: 358060
Summary:
Replace use of std::pair by creating a class for the debug value
instruction ranges instead. This is a preparatory refactoring for
improving handling of clobbered fragments.
In an upcoming commit the Begin pointer will become a PointerIntPair, so
it will be cleaner to have a getter for that.
Reviewers: aprantl
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59938
llvm-svn: 358059
Summary:
With MergeValues() removed, amend DebugLocEntry's constructor so that it
takes multiple values rather than a single, and keep non-fragment values
in OpenRanges, as this allows some cleanup of the code in
buildLocationList().
Reviewers: aprantl, dblaikie, loladiro
Reviewed By: aprantl
Subscribers: hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D59303
llvm-svn: 357988
Summary:
The MergeValues() function would try to merge two entries if they shared
the same beginning label. Having the same beginning label means that the
former entry's range would be empty; however, after D55919 we no longer
create entries for empty ranges, so we can no longer land in a situation
where that check in MergeValues would succeed. Instead, the "merging" is
done by keeping the live values from the preceding empty ranges in
OpenRanges, and adding them to the first non-empty range.
Reviewers: aprantl, dblaikie, loladiro
Reviewed By: aprantl
Subscribers: llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D59301
llvm-svn: 357974
COMMON blocks are a feature of Fortran that has no direct analog in C languages, but they are similar to data sections in assembly language programming. A COMMON block is a named area of memory that holds a collection of variables. Fortran subprograms may map the COMMON block memory area to their own, possibly distinct, non-empty list of variables. A Fortran COMMON block might look like the following example.
COMMON /ALPHA/ I, J
For this construct, the compiler generates a new scope-like DI construct (!DICommonBlock) into which variables (see I, J above) can be placed. As the common block implies a range of storage with global lifetime, the !DICommonBlock refers to a !DIGlobalVariable. The Fortran variable that comprise the COMMON block are also linked via metadata to offsets within the global variable that stands for the entire common block.
@alpha_ = common global %alphabytes_ zeroinitializer, align 64, !dbg !27, !dbg !30, !dbg !33!14 = distinct !DISubprogram(…)
!20 = distinct !DICommonBlock(scope: !14, declaration: !25, name: "alpha")
!25 = distinct !DIGlobalVariable(scope: !20, name: "common alpha", type: !24)
!27 = !DIGlobalVariableExpression(var: !25, expr: !DIExpression())
!29 = distinct !DIGlobalVariable(scope: !20, name: "i", file: !3, type: !28)
!30 = !DIGlobalVariableExpression(var: !29, expr: !DIExpression())
!31 = distinct !DIGlobalVariable(scope: !20, name: "j", file: !3, type: !28)
!32 = !DIExpression(DW_OP_plus_uconst, 4)
!33 = !DIGlobalVariableExpression(var: !31, expr: !32)
The DWARF generated for this is as follows.
DW_TAG_common_block:
DW_AT_name: alpha
DW_AT_location: @alpha_+0
DW_TAG_variable:
DW_AT_name: common alpha
DW_AT_type: array of 8 bytes
DW_AT_location: @alpha_+0
DW_TAG_variable:
DW_AT_name: i
DW_AT_type: integer*4
DW_AT_location: @Alpha+0
DW_TAG_variable:
DW_AT_name: j
DW_AT_type: integer*4
DW_AT_location: @Alpha+4
Patch by Eric Schweitz!
Differential Revision: https://reviews.llvm.org/D54327
llvm-svn: 357934
Create method `optForNone()` testing for the function level equivalent of
`-O0` and refactor appropriately.
Differential revision: https://reviews.llvm.org/D59852
llvm-svn: 357638
This patch adds an implementation of a PC-relative addressing sequence to be
used when -mcmodel=medium is specified. With absolute addressing, a 'medium'
codemodel may cause addresses to be out of range. This is because while
'medium' implies a 2 GiB addressing range, this 2 GiB can be at any offset as
opposed to 'small', which implies the first 2 GiB only.
Note that LLVM/Clang currently specifies code models differently to GCC, where
small and medium imply the same functionality as GCC's medlow and medany
respectively.
Differential Revision: https://reviews.llvm.org/D54143
Patch by Lewis Revill.
llvm-svn: 357393
A section containing metadata on remark diagnostics will be emitted if
the flag (-mllvm) -remarks-section is present.
For now, the metadata is:
* a magic number for remarks: "REMARKS\0"
* the version number: a little-endian uint64_t
* the absolute file path to the serialized remark diagnostics: a
null-terminated string.
Differential Revision: https://reviews.llvm.org/D59571
llvm-svn: 357043
This reverts commit rL357020.
The commit broke the test llvm/test/tools/llvm-objdump/embedded-source.test
on some builds including clang-ppc64be-linux-multistage,
clang-s390x-linux, clang-with-lto-ubuntu, clang-x64-windows-msvc,
llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast (and others).
llvm-svn: 357026
Reapply rL356941 after regenerating the object file in the failing test
llvm/test/tools/llvm-objdump/embedded-source.test from source.
Original commit message:
[llvm] Prevent duplicate files in debug line header in dwarf 5.
Motivation: In previous dwarf versions, file name indexes started from 1, and
the primary source file was not explicit. Dwarf 5 standard (6.2.4) prescribes
the primary source file to be explicitly given an entry with an index number 0.
The current implementation honors the specification by just duplicating the
main source file, once with index number 0, and later maybe with another
index number. While this is compliant with the letter of the standard, the
duplication causes problems for consumers of this information such as lldb.
(Some files are duplicated, where only some of them have a line table although
all refer to the same file)
With this change, dwarf 5 debug line section files always start from 0, and
the zeroth entry is not duplicated whenever possible. This requires different
handling of dwarf 4 and dwarf 5 during generation (e.g. when a function returns
an index zero for a file name, it signals an error in dwarf 4, but not in dwarf 5)
However, I think the minor complication is worth it, because it enables all
consumers (lldb, gdb, dwarfdump, objdump, and so on) to treat all files in the
file name list homogenously.
Tags: #llvm, #debug-info
Differential Revision: https://reviews.llvm.org/D59515
llvm-svn: 357018
Summary:
Motivation: In previous dwarf versions, file name indexes started from 1, and
the primary source file was not explicit. Dwarf 5 standard (6.2.4) prescribes
the primary source file to be explicitly given an entry with an index number 0.
The current implementation honors the specification by just duplicating the
main source file, once with index number 0, and later maybe with another
index number. While this is compliant with the letter of the standard, the
duplication causes problems for consumers of this information such as lldb.
(Some files are duplicated, where only some of them have a line table although
all refer to the same file)
With this change, dwarf 5 debug line section files always start from 0, and
the zeroth entry is not duplicated whenever possible. This requires different
handling of dwarf 4 and dwarf 5 during generation (e.g. when a function returns
an index zero for a file name, it signals an error in dwarf 4, but not in dwarf 5)
However, I think the minor complication is worth it, because it enables all
consumers (lldb, gdb, dwarfdump, objdump, and so on) to treat all files in the
file name list homogenously.
Reviewers: dblaikie, probinson, aprantl, espindola
Reviewed By: probinson
Subscribers: emaste, jvesely, nhaehnle, aprantl, javed.absar, arichardson, hiraditya, MaskRay, rupprecht, jdoerfert, llvm-commits
Tags: #llvm, #debug-info
Differential Revision: https://reviews.llvm.org/D59515
llvm-svn: 356941
Nothing prevents entries from being bigger than the 16 bit size field in
Dwarf < 5. For entries that are too big, just emit an empty entry
instead of crashing.
This fixes PR41038.
Reviewers: probinson, aprantl, davide
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D59518
llvm-svn: 356514
Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an additional bonus it paves the way for using other Dwarf
v5 ops that need to reference a base_type.
The new DW_OP_LLVM_convert is used from lib/Transforms/Utils/Local.cpp
to perform sext/zext on debug values but mainly the patch is about
preparing terrain for adding other Dwarf v5 ops that need to reference a
base_type.
For Dwarf v5 the op maps to DW_OP_convert and for earlier versions a
complex shift & mask pattern is generated to emulate sext/zext.
This is a recommit of r356442 with trivial fixes for the failing tests.
Differential Revision: https://reviews.llvm.org/D56587
llvm-svn: 356451
Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an additional bonus it paves the way for using other Dwarf
v5 ops that need to reference a base_type.
The new DW_OP_LLVM_convert is used from lib/Transforms/Utils/Local.cpp
to perform sext/zext on debug values but mainly the patch is about
preparing terrain for adding other Dwarf v5 ops that need to reference a
base_type.
For Dwarf v5 the op maps to DW_OP_convert and for earlier versions a
complex shift & mask pattern is generated to emulate sext/zext.
Differential Revision: https://reviews.llvm.org/D56587
llvm-svn: 356442
Summary:
Swift now generates PDBs for debugging on Windows. llvm and lldb
need a language enumerator value too properly handle the output
emitted by swiftc.
Subscribers: jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59231
llvm-svn: 355882
This allows us to store more info about where we're emitting the remarks
without cluttering LLVMContext. This is needed for future support for
the remark section.
Differential Revision: https://reviews.llvm.org/D58996
llvm-svn: 355507
When using full LTO it is possible that template function definition DIE
is bound to one compilation unit and it's declaration to another. We should
add function declaration attributes on behalf of its owner CU otherwise
we may end up with malformed file identifier in function declaration
DW_AT_decl_file attribute.
Differential revision: https://reviews.llvm.org/D58538
llvm-svn: 354978
Summary:
This is a follow-up to D57510. This patch stops DebugHandlerBase from
changing the starting label for the first non-overlapping,
register-described parameter DBG_VALUEs to the beginning of the
function. That code did not consider what defined the registers, which
could result in the ranges for the debug values starting before their
defining instructions. We currently do not emit debug values for
constant values directly at the start of the function, so this code is
still useful for such values, but my intention is to remove the code
from DebugHandlerBase completely when we get there. One reason for
removing it is that the code violates the history map's ranges, which I
think can make it quite confusing when troubleshooting.
In D57510, PrologEpilogInserter was amended so that parameter DBG_VALUEs
now are kept at the start of the entry block, even after emission of
prologue code. That was done to reduce the degradation of debug
completeness from this patch. PR40638 is another example, where the
lexical-scope trimming that LDV does, in combination with scheduling,
results in instructions after the prologue being left without locations.
There might be other cases where the DBG_VALUEs are pushed further down,
for which the DebugHandlerBase code may be helpful, but as it now quite
often result in incorrect locations, even after the prologue, it seems
better to remove that code, and try to work our way up with accurate
locations.
In the long run we should maybe not aim to provide accurate locations
inside the prologue. Some single location descriptions, at least those
referring to stack values, generate inaccurate values inside the
epilogue, so we maybe should not aim to achieve accuracy for location
lists. However, it seems that we now emit line number programs that can
result in GDB and LLDB stopping inside the prologue when doing line
number stepping into functions. See PR40188 for more information.
A summary of some of the changed test cases is available in PR40188#c2.
Reviewers: aprantl, dblaikie, rnk, jmorse
Reviewed By: aprantl
Subscribers: jdoerfert, jholewinski, jvesely, javed.absar, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D57511
llvm-svn: 353928
This configuration (due to r349207) was intended not to emit any DWO CU,
but a degenerate CU was still being emitted - containing a header and a
DW_TAG_compile_unit with no attributes.
Under that situation, emit nothing to the .dwo file. (since this is a
dynamic property of the input the .dwo file is still emitted, just with
nothing in it (so a valid, but empty, ELF file) - if some other CU
didn't satisfy this criteria, its DWO CU would still go there, etc)
llvm-svn: 353771
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html
This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.
This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.
There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.
Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii
Differential Revision: https://reviews.llvm.org/D53765
llvm-svn: 353563
Summary:
According to
https://docs.nvidia.com/cuda/archive/10.0/ptx-writers-guide-to-interoperability/index.html#cuda-specific-dwarf,
the compiler should emit the DW_AT_address_class attribute for all
variable and parameter. It means, that DW_AT_address_class attribute
should be used in the non-standard way to support compatibility with the
cuda-gdb debugger.
Clang is able to generate the information about the variable address
class. This information is emitted as the expression sequence
`DW_OP_constu <DWARF Address Space> DW_OP_swap DW_OP_xderef`. The patch
tries to find all such expressions and transform them into
`DW_AT_address_class <DWARF Address Space>` if target is NVPTX and the debugger is gdb.
If the expression is not found, then default values are used. For the
local variables <DWARF Address Space> is set to ADDR_local_space(6), for
the globals <DWARF Address Space> is set to ADDR_global_space(5). The
values are taken from the table in the same section 5.2. CUDA-Specific
DWARF Definitions.
Reviewers: echristo, probinson
Subscribers: jholewinski, aprantl, llvm-commits
Differential Revision: https://reviews.llvm.org/D57157
llvm-svn: 353203
Aliases of functions are now marked as function symbols even if
they are bitcast to some other other non-function type.
This is important for WebAssembly where object and function
symbols can't alias each other.
Fixes PR38866
Differential Revision: https://reviews.llvm.org/D57538
llvm-svn: 353109
The LiveDebugValues pass recognizes spills but not restores, which can
cause large gaps in location information for some variables, depending
on control flow. This patch make LiveDebugValues recognize restores and
generate appropriate DBG_VALUE instructions.
This patch was posted previously with r352642 and reverted in r352666 due
to buildbot errors. A missing return statement was the cause for the
failures.
Reviewers: aprantl, NicolaPrica
Differential Revision: https://reviews.llvm.org/D57271
llvm-svn: 353089
This patch removes hidden codegen flag -print-schedule effectively reverting the
logic originally committed as r300311
(https://llvm.org/viewvc/llvm-project?view=revision&revision=300311).
Flag -print-schedule was originally introduced by r300311 to address PR32216
(https://bugs.llvm.org/show_bug.cgi?id=32216). That bug was about adding "Better
testing of schedule model instruction latencies/throughputs".
These days, we can use llvm-mca to test scheduling models. So there is no longer
a need for flag -print-schedule in LLVM. The main use case for PR32216 is
now addressed by llvm-mca.
Flag -print-schedule is mainly used for debugging purposes, and it is only
actually used by x86 specific tests. We already have extensive (latency and
throughput) tests under "test/tools/llvm-mca" for X86 processor models. That
means, most (if not all) existing -print-schedule tests for X86 are redundant.
When flag -print-schedule was first added to LLVM, several files had to be
modified; a few APIs gained new arguments (see for example method
MCAsmStreamer::EmitInstruction), and MCSubtargetInfo/TargetSubtargetInfo gained
a couple of getSchedInfoStr() methods.
Method getSchedInfoStr() had to originally work for both MCInst and
MachineInstr. The original implmentation of getSchedInfoStr() introduced a
subtle layering violation (reported as PR37160 and then fixed/worked-around by
r330615).
In retrospect, that new API could have been designed more optimally. We can
always query MCSchedModel to get the latency and throughput. More importantly,
the "sched-info" string should not have been generated by the subtarget.
Note, r317782 fixed an issue where "print-schedule" didn't work very well in the
presence of inline assembly. That commit is also reverted by this change.
Differential Revision: https://reviews.llvm.org/D57244
llvm-svn: 353043
Summary: This fixes using the correct stack registers for SEH when stack realignment is needed or when variable size objects are present.
Reviewers: rnk, efriedma, ssijaric, TomTan
Reviewed By: rnk, efriedma
Subscribers: javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D57183
llvm-svn: 352923
The LiveDebugValues pass recognizes spills but not restores, which can
cause large gaps in location information for some variables, depending
on control flow. This patch make LiveDebugValues recognize restores and
generate appropriate DBG_VALUE instructions.
Reviewers: aprantl, NicolaPrica
Differential Revision: https://reviews.llvm.org/D57271
llvm-svn: 352642
Summary:
This switches the EH implementation to the new proposal:
https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md
(The previous proposal was
https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md)
- Instruction changes
- Now we have one single `catch` instruction that returns a except_ref
value
- `throw` now can take variable number of operations
- `rethrow` does not have 'depth' argument anymore
- `br_on_exn` queries an except_ref to see if it matches the tag and
branches to the given label if true.
- `extract_exception` is a pseudo instruction that simulates popping
values from wasm stack. This is to make `br_on_exn`, a very special
instruction, work: `br_on_exn` puts values onto the stack only if it
is taken, and the # of values can vay depending on the tag.
- Now there's only one `catch` per `try`, this patch removes all special
handling for terminate pad with a call to `__clang_call_terminate`.
Before it was the only case there are two catch clauses (a normal
`catch` and `catch_all` per `try`).
- Make `rethrow` act as a terminator like `throw`. This splits BB after
`rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable`
after `rethrow` in LateEHPrepare.
- Now we stop at all catchpads (because we add wasm `catch` instruction
that catches all exceptions), this creates new
`findWasmUnwindDestinations` function in SelectionDAGBuilder.
- Now we use `br_on_exn` instrution to figure out if an except_ref
matches the current tag or not, LateEHPrepare generates this sequence
for catch pads:
```
catch
block i32
br_on_exn $__cpp_exception
end_block
extract_exception
```
- Branch analysis for `br_on_exn` in WebAssemblyInstrInfo
- Other various misc. changes to switch to the new proposal.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D57134
llvm-svn: 352598
N_FUNC_COLD is a new MachO symbol attribute. It's a hint to the linker
to order a symbol towards the end of its section, to improve locality.
Example:
```
void a1() {}
__attribute__((cold)) void a2() {}
void a3() {}
int main() {
a1();
a2();
a3();
return 0;
}
```
A linker that supports N_FUNC_COLD will order _a2 to the end of the text
section. From `nm -njU` output, we see:
```
_a1
_a3
_main
_a2
```
Differential Revision: https://reviews.llvm.org/D57190
llvm-svn: 352227
Summary:
`CodeViewDebug::lowerTypeMemberFunction` used to default to a `Void`
return type if the function's type array was empty. After D54667, it
started blindly indexing the 0th item for the return type, which fails
in `getOperand` for empty arrays if assertions are enabled.
This patch restores the `Void` return type for empty type arrays, and
adds a test generated by Rust in line-only debuginfo mode.
Reviewers: zturner, rnk
Reviewed By: rnk
Subscribers: hiraditya, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D57070
llvm-svn: 351910
Summary: Initial function labels must follow the debug location for the correct relocation info generation.
Reviewers: tra, jlebar, echristo
Subscribers: jholewinski, llvm-commits
Differential Revision: https://reviews.llvm.org/D45784
llvm-svn: 351843
Nilanjana Basu