This patch causes invalid DWARF to be generated in some cases of LTO +
Split DWARF - follow-up on the original review thread (D113741) contains
further detail and test cases.
This reverts commit 75b622a7959479ccdb758ebe0973061b7b4fcacd.
This reverts commit b6ccca217c35a95b8c2a337a7801b37cb23dbae2.
This reverts commit 514d37441918dd04a2cd4f35c08959d7c3ff096d.
DwarfExpression::addUnsignedConstant(const APInt &Value) only supports
wider-than-64-bit values when it is used to emit a top-level DWARF
expression representing the location of a variable. Before this change,
it was possible to call addUnsignedConstant on >64 bit values within a
subexpression when substituting DW_OP_LLVM_arg values.
This can trigger an assertion failure (e.g. PR52584, PR52333) when it
happens in a fragment (DW_OP_LLVM_fragment) expression, as
addUnsignedConstant on >64 bit values splits the constant into separate
DW_OP_pieces, which modifies DwarfExpression::OffsetInBits.
This change papers over the assertion errors by bailing on overly wide
DW_OP_LLVM_arg values. A more comprehensive fix might be to be to split
wide values into pointer-sized fragments.
[0] https://github.com/llvm/llvm-project/blob/e71fa03/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp#L799-L805
Patch by Ricky Zhou!
Differential Revision: https://reviews.llvm.org/D115343
This reverts commits
* ee691970a9a85470948ada623c31f0ab8773617c (D113741),
* 79d3132998b2828be8f7d2ec411f91fb11b3e01f (D114705)
due to lldb and dexter test failures.
No functional changes intended.
Before this patch DwarfCompileUnit::createScopeChildrenDIE() and
DwarfCompileUnit::createAndAddScopeChildrenDIE() used to emit child subtrees
and then when all the children get created, attach them to a parent scope DIE.
However, when a DIE doesn't have a parent, all the requests for its unit DIE
fail.
Currently, this is not a big issue since it isn't usually needed to know unit DIE
for a local (function-scoped) entity. But once we introduce lexical blocks as
a valid scope for global variables (static locals) and type DIEs, any requests
for a unit DIE need to be guarded against local scope due to the potential
absence of the DIE's parent.
To avoid the aforementioned issue, this patch refactors a few DwarfCompileUnit
methods to support the idea of attaching a DIE to its parent as close to the
creation of this DIE as possible.
Reviewed By: ellis
Differential Revision: https://reviews.llvm.org/D114350
Instead of popping them and then immediately throwing them away, we can
just filter out globals and items in different scopes before adding them
to WorkList. Shouldn't change anything but keep the queue smaller.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D113864
In a LTO build, the `end_sequence` in debug_line table for each compile unit (CU) points the end of text section which merged all CUs. The `end_sequence` needs to point to the end of each CU's range. This bug often causes invalid `debug_line` table in the final `.dSYM` binary for MachO after running `dsymutil` which tries to compensate an out-of-range address of `end_sequence`.
The fix is to sync the line table termination with the range operations that are already maintained in DwarfDebug. When CU or section changes, or nodebug functions appear or module is finished, the prior pending line table is terminated using the last range label. In the MC path where no range is tracked, the old logic is conservatively used to end the line table using the section end symbol.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D108261
For global variables and common blocks there is no way to create entities
through getOrCreateContextDIE(), so no need to obtain the context first.
Differential Revision: https://reviews.llvm.org/D113651
When emitting a reloc for the Wasm global __stack_pointer, it was inadvertedly added to the symbols used for generating aranges, which caused some aranges to use it as the end symbol in a symbol diff, which caused a reloc for it to be emitted, which then caused an assert in `wasm64` since we have no 64-bit relocs for Wasm globals.
Fixes: https://bugs.llvm.org/show_bug.cgi?id=52376
Differential Revision: https://reviews.llvm.org/D113438
When compiling for the RWPI relocation model the debug information is wrong:
* the debug location is described as { DW_OP_addr Var }
instead of { DW_OP_constNu Var DW_OP_bregX 0 DW_OP_plus }
* the relocation type is R_ARM_ABS32 instead of R_ARM_SBREL32
Differential Revision: https://reviews.llvm.org/D111404
New field `elements` is added to '!DIImportedEntity', representing
list of aliased entities.
This is needed to dump optimized debugging information where all names
in a module are imported, but a few names are imported with overriding
aliases.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D109343
A new LLVM specific TAG DW_TAG_LLVM_annotation is added.
The name is suggested by Paul Robinson ([1]).
Currently, this tag is used to output __attribute__((btf_tag("string")))
annotations in dwarf. The following is an example for a global
variable with two btf_tag attributes:
0x0000002a: DW_TAG_variable
DW_AT_name ("g1")
DW_AT_type (0x00000052 "int")
DW_AT_external (true)
DW_AT_decl_file ("/tmp/home/yhs/work/tests/llvm/btf_tag/t.c")
DW_AT_decl_line (8)
DW_AT_location (DW_OP_addr 0x0)
0x0000003f: DW_TAG_LLVM_annotation
DW_AT_name ("btf_tag")
DW_AT_const_value ("tag1")
0x00000048: DW_TAG_LLVM_annotation
DW_AT_name ("btf_tag")
DW_AT_const_value ("tag2")
0x00000051: NULL
In the future, DW_TAG_LLVM_annotation may encode other type
of non-string const value.
[1] https://lists.llvm.org/pipermail/llvm-dev/2021-June/151250.html
Differential Revision: https://reviews.llvm.org/D106621
This patch is a revert of e08f205f5c2c. In that patch, DW_TAG_subprograms
were permitted to be referenced across CU boundaries, to improve stack
trace construction using call site information. Unfortunately, as
documented in PR48790, the way that subprograms are "owned" by dwarf units
is sufficiently complicated that subprograms end up in unexpected units,
invalidating cross-unit references.
There's no obvious way to easily fix this, and several attempts have
failed. Revert this to ensure correct DWARF is always emitted.
Three tests change in addition to the reversion, but they're all very
light alterations.
Differential Revision: https://reviews.llvm.org/D107076
Add a new wrapper function addAttribute() for Die.addValue() function,
so we can do some attributes control in one single interface.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D101125
Negative numbers are represented using DW_OP_consts along with signed representation
of the number as the argument.
Test case IR is generated using Fortran front-end.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D99273
For locally scoped lambdas like this there's no particular benefit to
explicitly listing captures - or avoiding capturing this. Switch to [&]
and make it all easier to maintain.
(& driveby change std::function to llvm::function_ref)
This patch allows DBG_VALUE_LIST instructions to be emitted to DWARF with valid
DW_AT_locations. This change mainly affects DbgEntityHistoryCalculator, which
now tracks multiple registers per value, and DwarfDebug+DwarfExpression, which
can now emit multiple machine locations as part of a DWARF expression.
Differential Revision: https://reviews.llvm.org/D83495
Experimental, using non-existent DWARF support to use an expr for the
location involving an addr_index (to compute address + offset so
addresses can be reused in more places).
The global variable debug info had to be deferred until the end of the
module (so bss variables would all be emitted first - so their labels
would have the relevant section). Non-bss variables seemed to not have
their label assigned to a section even at the end of the module, so I
didn't know what to do there.
Also, the hashing code is broken - doesn't know how to hash these
expressions (& isn't hashing anything inside subprograms, which seems
problematic), so for test purposes this change just skips the hash
computation. (GCC's actually overly sensitive in its hash function, it
seems - I'm forgetting the specific case right now - anyway, we might
want to just use the frontend-known file hash and give up on optimistic
.dwo/.dwp reuse)
A struct in C passed by value did not get debug information. Such values are currently
lowered to a Wasm local even in -O0 (not to an alloca like on other archs), which becomes
a Target Index operand (TI_LOCAL). The DWARF writing code was not emitting locations
in for TI's specifically if the location is a single range (not a list).
In addition, the ExplicitLocals pass which removes the ARGUMENT pseudo instructions did
not update the associated DBG_VALUEs, and couldn't even find these values since the code
assumed such instructions are adjacent, which is not the case here.
Also fixed asm printing of TIs needed by a test.
Differential Revision: https://reviews.llvm.org/D94140
When using dbg.declare, the debug-info is generated from a list of
locals rather than through DBG_VALUE instructions in the MIR.
This patch is different from D90020 because it emits the DWARF
location expressions from that list of locals directly.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D90044
Given the ability provided by DWARFv5 rnglists to reuse addresses in the
address pool, it can be advantageous to object file size to use range
encodings even when the range could be described by a direct low/high
pc.
Add a flag to allow enabling this in DWARFv5 for the purpose of
experimentation/data gathering.
It might be that it makes sense to enable this functionality by default
for DWARFv5 + Split DWARF at least, where the tradeoff/desire to
optimize for .o file size is more explicit and .o bytes are higher
priority than .dwo bytes.
To accommodate frame layouts that have both fixed and scalable objects
on the stack, describing a stack location or offset using a pointer + uint64_t
is not sufficient. For this reason, we've introduced the StackOffset class,
which models both the fixed- and scalable sized offsets.
The TargetFrameLowering::getFrameIndexReference is made to return a StackOffset,
so that this can be used in other interfaces, such as to eliminate frame indices
in PEI or to emit Debug locations for variables on the stack.
This patch is purely mechanical and doesn't change the behaviour of how
the result of this function is used for fixed-sized offsets. The patch adds
various checks to assert that the offset has no scalable component, as frame
offsets with a scalable component are not yet supported in various places.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D90018
This is needed to support fortran assumed rank arrays which
have runtime rank.
Summary:
Fortran assumed rank arrays have dynamic rank. DWARF TAG
DW_TAG_generic_subrange is needed to support that.
Testing:
unit test cases added (hand-written)
check llvm
check debug-info
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D89218
Initial support for dwarf fission sections (-gsplit-dwarf) on wasm.
The most interesting change is support for writing 2 files (.o and .dwo) in the
wasm object writer. My approach moves object-writing logic into its own function
and calls it twice, swapping out the endian::Writer (W) in between calls.
It also splits the import-preparation step into its own function (and skips it when writing a dwo).
Differential Revision: https://reviews.llvm.org/D85685
The patch uses a common method to determine the appropriate form for
the value of the attribute.
Differential Revision: https://reviews.llvm.org/D87016
DIELabel can emit only 32- or 64-bit values, while it was created in
some places with DW_FORM_udata, which implies emitting uleb128.
Nevertheless, these places also expected to emit U32 or U64, but just
used a misleading DWARF form. The patch updates those places to use more
appropriate DWARF forms and restricts DIELabel::SizeOf() to accept only
forms that are actually used in the LLVM codebase.
Differential Revision: https://reviews.llvm.org/D84094
Emit DWARF 5 call-site symbols even though DWARF 4 is set,
only in the case of LLDB tuning.
This patch addresses PR46643.
Differential Revision: https://reviews.llvm.org/D83463
Summary:
This support is needed for the Fortran array variables with pointer/allocatable
attribute. This support enables debugger to identify the status of variable
whether that is currently allocated/associated.
for pointer array (before allocation/association)
without DW_AT_associated
(gdb) pt ptr
type = integer (140737345375288:140737354129776)
(gdb) p ptr
value requires 35017956 bytes, which is more than max-value-size
with DW_AT_associated
(gdb) pt ptr
type = integer (:)
(gdb) p ptr
$1 = <not associated>
for allocatable array (before allocation)
without DW_AT_allocated
(gdb) pt arr
type = integer (140737345375288:140737354129776)
(gdb) p arr
value requires 35017956 bytes, which is more than max-value-size
with DW_AT_allocated
(gdb) pt arr
type = integer, allocatable (:)
(gdb) p arr
$1 = <not allocated>
Testing
- unit test cases added
- check-llvm
- check-debuginfo
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D83544
For now, DIEExpr is used only in two places:
1) in the debug info library unit test suite to emit
a DW_AT_str_offsets_base attribute with the DW_FORM_sec_offset
form, see dwarfgen::DIE::addStrOffsetsBaseAttribute();
2) in DwarfCompileUnit::addLocationAttribute() to generate the location
attribute for a TLS variable.
The later case used an incorrect DWARF form of DW_FORM_udata, which
implies storing an uleb128 value, not a 4/8 byte constant. The generated
result was as expected because DIEExpr::SizeOf() did not handle the used
form, but returned the size of the code pointer by default.
The patch fixes the issue by using more appropriate DWARF forms for
the problematic case and making DIEExpr::SizeOf() more straightforward.
Differential Revision: https://reviews.llvm.org/D83958
This patch uses ranges for debug information when a function contains basic block sections rather than using [lowpc, highpc]. This is also the first in a series of patches for debug info and does not contain the support for linker relaxation. That will be done as a follow up patch.
Differential Revision: https://reviews.llvm.org/D78851
Commit d77ae1552fc2 ("[DebugInfo] Support to emit debugInfo
for extern variables") added support to emit debuginfo
for extern variables. Currently, only BPF target enables to
emit debuginfo for extern variables.
But if the extern variable has "void" type, the compilation will
fail.
-bash-4.4$ cat t.c
extern void bla;
void *test() {
void *x = &bla;
return x;
}
-bash-4.4$ clang -target bpf -g -O2 -S t.c
missing global variable type
!1 = distinct !DIGlobalVariable(name: "bla", scope: !2, file: !3, line: 1,
isLocal: false, isDefinition: false)
...
fatal error: error in backend: Broken module found, compilation aborted!
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace,
preprocessed source, and associated run script.
Stack dump:
...
The IR requires a DIGlobalVariable must have a valid type and the
"void" type does not generate any type, hence the above fatal error.
Note that if the extern variable is defined as "const void", the
compilation will succeed.
-bash-4.4$ cat t.c
extern const void bla;
const void *test() {
const void *x = &bla;
return x;
}
-bash-4.4$ clang -target bpf -g -O2 -S t.c
-bash-4.4$ cat t.ll
...
!1 = distinct !DIGlobalVariable(name: "bla", scope: !2, file: !3, line: 1,
type: !6, isLocal: false, isDefinition: false)
!6 = !DIDerivedType(tag: DW_TAG_const_type, baseType: null)
...
Since currently, "const void extern_var" is supported by the
debug info, it is natural that "void extern_var" should also
be supported. This patch disabled assertion of "void extern_var"
in IR verifier and add proper guarding when emiting potential
null debug info type to dwarf types.
Differential Revision: https://reviews.llvm.org/D81131
This patch upgrades DISubrange to support fortran requirements.
Summary:
Below are the updates/addition of fields.
lowerBound - Now accepts signed integer or DIVariable or DIExpression,
earlier it accepted only signed integer.
upperBound - This field is now added and accepts signed interger or
DIVariable or DIExpression.
stride - This field is now added and accepts signed interger or
DIVariable or DIExpression.
This is required to describe bounds of array which are known at runtime.
Testing:
unit test cases added (hand-written)
check clang
check llvm
check debug-info
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D80197
Summary:
A struct argument can be passed-by-value to a callee via a pointer to a
temporary stack copy. Add support for emitting an entry value DBG_VALUE
when an indirect parameter DBG_VALUE becomes unavailable. This is done
by omitting DW_OP_stack_value from the entry value expression, to make
the expression describe the location of an object.
rdar://63373691
Reviewers: djtodoro, aprantl, dstenb
Subscribers: hiraditya, lldb-commits, llvm-commits
Tags: #lldb, #llvm
Differential Revision: https://reviews.llvm.org/D80345
This patch adds support for DWARF attribute DW_AT_data_location.
Summary:
Dynamic arrays in fortran are described by array descriptor and
data allocation address. Former is mapped to DW_AT_location and
later is mapped to DW_AT_data_location.
Testing:
unit test cases added (hand-written)
check llvm
check debug-info
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D79592
