Summary:
Internally in LLVM's metadata we use DW_OP_entry_value operations with
the same semantics as DWARF; that is, its operand specifies the number
of bytes that the entry value covers.
At the time of emitting entry values we don't know the emitted size of
the DWARF expression that the entry value will cover. Currently the size
is hardcoded to 1 in DIExpression, and other values causes the verifier
to fail. As the size is 1, that effectively means that we can only have
valid entry values for registers that can be encoded in one byte, which
are the registers with DWARF numbers 0 to 31 (as they can be encoded as
single-byte DW_OP_reg0..DW_OP_reg31 rather than a multi-byte
DW_OP_regx). It is a bit confusing, but it seems like llvm-dwarfdump
will print an operation "correctly", even if the byte size is less than
that, which may make it seem that we emit correct DWARF for registers
with DWARF numbers > 31. If you instead use readelf for such cases, it
will interpret the number of specified bytes as a DWARF expression. This
seems like a limitation in llvm-dwarfdump.
As suggested in D66746, a way forward would be to add an internal
variant of DW_OP_entry_value, DW_OP_LLVM_entry_value, whose operand
instead specifies the number of operations that the entry value covers,
and we then translate that into the byte size at the time of emission.
In this patch that internal operation is added. This patch keeps the
limitation that a entry value can only be applied to simple register
locations, but it will fix the issue with the size operand being
incorrect for DWARF numbers > 31.
Reviewers: aprantl, vsk, djtodoro, NikolaPrica
Reviewed By: aprantl
Subscribers: jyknight, fedor.sergeev, hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D67492
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@374881 91177308-0d34-0410-b5e6-96231b3b80d8
An incorrect verification error revealed that the list of type tags was
incomplete. This patch adds the missing types by adding a tag kind to
the Dwarf.def file, which is used by the `isType` function.
A test was added for the original verification error.
Differential revision: https://reviews.llvm.org/D65914
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368718 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363635 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356451 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356442 91177308-0d34-0410-b5e6-96231b3b80d8
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
This is to address post-commit feedback from Paul Robinson on r348954.
The original commit misinterprets count and upper bound as the same thing (I thought I saw GCC producing an upper bound the same as Clang's count, but GCC correctly produces an upper bound that's one less than the count (in C, that is, where arrays are zero indexed)).
I want to preserve the C-like output for the common case, so in the absence of a lower bound the count (or one greater than the upper bound) is rendered between []. In the trickier cases, where a lower bound is specified, a half-open range is used (eg: lower bound 1, count 2 would be "[1, 3)" and an unknown parts use a '?' (eg: "[1, ?)" or "[?, 7)" or "[?, ? + 3)").
Reviewers: aprantl, probinson, JDevlieghere
Differential Revision: https://reviews.llvm.org/D55721
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349670 91177308-0d34-0410-b5e6-96231b3b80d8
- Reapply changes intially introduced in r343089
- The archtecture info is no longer loaded whenever a DWARFContext is created
- The runtimes libraries (santiziers) make use of the dwarf context classes but
do not intialise the target info
- The architecture of the object can be obtained without loading the target info
- Adding a method to the dwarf context to get this information and multiplex the
string printing later on
Differential Revision: https://reviews.llvm.org/D55774
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349472 91177308-0d34-0410-b5e6-96231b3b80d8
- Add fix so that all code paths that create DWARFContext
with an ObjectFile initialise the target architecture in the context
- Add an assert that the Arch is known in the Dwarf CallFrameString method
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343317 91177308-0d34-0410-b5e6-96231b3b80d8
This caused the DebugInfo/Sparc/gnu-window-save.ll test to fail.
> Functions that have signed return addresses need additional dwarf support:
> - After signing the LR, and before authenticating it, the LR register is in a
> state the is unusable by a debugger or unwinder
> - To account for this a new directive, .cfi_negate_ra_state, is added
> - This directive says the signed state of the LR register has now changed,
> i.e. unsigned -> signed or signed -> unsigned
> - This directive has the same CFA code as the SPARC directive GNU_window_save
> (0x2d), adding a macro to account for multiply defined codes
> - This patch matches the gcc implementation of this support:
> https://patchwork.ozlabs.org/patch/800271/
>
> Differential Revision: https://reviews.llvm.org/D50136
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Functions that have signed return addresses need additional dwarf support:
- After signing the LR, and before authenticating it, the LR register is in a
state the is unusable by a debugger or unwinder
- To account for this a new directive, .cfi_negate_ra_state, is added
- This directive says the signed state of the LR register has now changed,
i.e. unsigned -> signed or signed -> unsigned
- This directive has the same CFA code as the SPARC directive GNU_window_save
(0x2d), adding a macro to account for multiply defined codes
- This patch matches the gcc implementation of this support:
https://patchwork.ozlabs.org/patch/800271/
Differential Revision: https://reviews.llvm.org/D50136
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343089 91177308-0d34-0410-b5e6-96231b3b80d8
For instance, When dumping .apple_types, the second atom represents the
DW_TAG. In addition to printing the raw value, we now also pretty print
the value if the ATOM tells us how.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337026 91177308-0d34-0410-b5e6-96231b3b80d8
Instead of printing
DW_AT_APPLE_runtime_class (0x10)
we now print
DW_AT_APPLE_runtime_class (DW_LANG_ObjC)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337011 91177308-0d34-0410-b5e6-96231b3b80d8
- constexpr is needed for out-of-class definition of the Type static
member by some compilers
- MSVC is confused by the initialization of the static constexpr char[]
member when it happens in a template specialization. Explicitly
specifying the length of the array seems to be enough to help it
figure things out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328093 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
We have had at least three pieces of code (in DWARFAbbreviationDeclaration,
DWARFAcceleratorTable and DWARFDie) that have hand-rolled support for
dumping unknown dwarf enum values. While not terrible, they are a bit
distracting and enable small differences to creep in (Unknown_ffff vs.
Unknown_0xffff). I ended up needing to add a fourth place
(DWARFVerifier), so it seems it would be a good time to centralize.
This patch creates an alternative to the XXXString dumping functions in
the BinaryFormat library, which formats an unknown value as
DW_TYPE_unknown_1234, instead of just an empty string. It is based on
the formatv function, as that allows us to avoid materializing the
string for unknown values (and because this way I don't have to invent a
name for the new functions :P).
In this patch I add formatters for dwarf attributes, forms, tags, and
index attributes as these are the ones in use currently, but adding
other enums is straight-forward.
Reviewers: dblaikie, JDevlieghere, aprantl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44570
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328090 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch replaces the two switches which are deducing the size of
various forms with a single implementation. I have put the new
implementation into BinaryFormat, to avoid introducing dependencies
between the two independent libraries (DebugInfo and CodeGen) that need
this functionality.
Reviewers: aprantl, JDevlieghere, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44418
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327486 91177308-0d34-0410-b5e6-96231b3b80d8
Adding verbose dumping to the recent implementation of dumping of v5 range list entries.
We're capturing the entries as is as they come in during extraction, including their file offset,
so we can dump them in more detail.
The offset table entries which are table-relative are shown as is (as in non-verbose mode)
and with the actual file offset they map to.
Reviewers: dblaikie, aprantl, jdevlieghere, jhenderson
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43366
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327059 91177308-0d34-0410-b5e6-96231b3b80d8
n Rust, an enum that carries data in the variants is, essentially, a
discriminated union. Furthermore, the Rust compiler will perform
space optimizations on such enums in some situations. Previously,
DWARF for these constructs was emitted using a hack (a magic field
name); but this approach stopped working when more space optimizations
were added in https://github.com/rust-lang/rust/pull/45225.
This patch changes LLVM to allow discriminated unions to be
represented in DWARF. It adds createDiscriminatedUnionType and
createDiscriminatedMemberType to DIBuilder and then arranges for this
to be emitted using DWARF's DW_TAG_variant_part and DW_TAG_variant.
Note that DWARF requires that a discriminated union be represented as
a structure with a variant part. However, as Rust only needs to emit
pure discriminated unions, this is what I chose to expose on
DIBuilder.
Patch by Tom Tromey!
Differential Revision: https://reviews.llvm.org/D42082
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324426 91177308-0d34-0410-b5e6-96231b3b80d8
This patch moves the DJB hash to support. This is consistent with other
hashing algorithms living there. The hash is used by the DWARF
accelerator tables. We're doing this now because the hashing function is
needed by dsymutil and we don't want to link against libBinaryFormat.
Differential revision: https://reviews.llvm.org/D42594
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This patch extends the atom types used by the Apple accelerator tables
with two dsymutil extensions:
- DW_ATOM_type_type_flags
- DW_ATOM_qual_name_hash
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323414 91177308-0d34-0410-b5e6-96231b3b80d8
This allows us to specify the magic number for the DJB hash function.
This feature is needed by dsymutil to emit Apple types accelerator
table.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323341 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This adds a definition of the .debug_names section and the new constants
(DW_IDX_???) which are used in it.
Reviewers: JDevlieghere, aprantl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42296
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323084 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements the dwarfdump option --find=<name>. This option
looks for a DIE in the accelerator tables and dumps it if found. This
initial patch only adds support for .apple_names to keep the review
small, adding the other sections and pubnames support should be
trivial though.
Differential Revision: https://reviews.llvm.org/D38282
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This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
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