The AsmPrinter currently assumes that a Debug Variable will have all of its
fragments with the same "kind" of location (i.e. all in the stack or all in
entry values). This is not enforced by the verifier, so it needs to be handled
properly. Until we do so, we conservatively drop one of the fragments.
Differential Revision: https://reviews.llvm.org/D159468
This potentially has a slightly positive performance impact, as
std::visit can be implemented as a `switch`-like jump rather than
a series of `if`s.
More importantly, the reader can be confident is no overlap between the
cases.
Differential Revision: https://reviews.llvm.org/D158678
Only a subset of the fields of DbgVariable are meaningful at any time,
and some fields are re-used for multiple purposes (for example
FrameIndexExprs is used with a throw-away frame-index of 0 to hold a
single DIExpression without needing to add another member). The exact
invariants must be reverse-engineered by inspecting the actual use of
the class, its imprecise/outdated doc-comment, and some asserts.
Refactor DbgVariable into a sum type by inheriting from std::variant.
This makes the active fields for any given state explicit and removes
the need to re-use fields in disparate contexts. As a bonus, it seems to
reduce the size on my x86_64 linux box from 144 bytes to 96 bytes.
There is some potential cost to `std::get` as it must check the active
alternative even when context or an assert obviates it. To try to help
ensure the compiler can optimize out the checks the patch also adds a
helper `get` method which uses the noexcept `std::get_if`.
Some of the extra cost would also be avoided more cleanly with a
refactor that exposes the alternative types in the public interface,
which will come in another patch.
Differential Revision: https://reviews.llvm.org/D158675
I would like to steal one of these bits to denote whether a kind may be
spilled by the register allocator or not, but I'm afraid to touch of any
this code using bitwise operands.
Make flags a first class type using bitfields, rather than launder data
around via `unsigned`.
These 2 functions could be called by AsmPrinter::doInitialization in
AsmPrinter.cpp. doInitialization init MMI in the beginning`MMI = MMIWP ?
&MMIWP->getMMI() : nullptr;`, MMI has the possibility to be nullptr,
which could make the later deref crash. I think in most time MMI could
not be nullptr, but from the view of function implementation, it could
be, so I'd like to add assert to it, if this could be a problem, then we
could avoid crash.
With the large code model, the label difference may not fit into 32 bits.
Even if we assume that any individual function is no larger than 2^32
and use a difference from the function entry to the target destination,
things like BOLT can rearrange blocks (even if BOLT doesn't necessarily
work with the large code model right now).
set directives avoid static relocations in some 32-bit entry cases, but
don't worry about set directives for 64-bit jump table entries (we can
do that later if somebody really cares about it).
check-llvm in a bootstrapped clang with the large code model passes.
Fixes#62894
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D159297
The CodeView `S_ARMSWITCHTABLE` debug symbol is used to describe the layout of a jump table, it contains the following information:
* The address of the branch instruction that uses the jump table.
* The address of the jump table.
* The "base" address that the values in the jump table are relative to.
* The type of each entry (absolute pointer, a relative integer, a relative integer that is shifted).
Together this information can be used by debuggers and binary analysis tools to understand what an jump table indirect branch is doing and where it might jump to.
Documentation for the symbol can be found in the Microsoft PDB library dumper: 0fe89a942f/cvdump/dumpsym7.cpp (L5518)
This change adds support to LLVM to emit the `S_ARMSWITCHTABLE` debug symbol as well as to dump it out (for testing purposes).
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D149367
Should add some minor type safety to the use of this information, since
there's quite a bit of metadata being laundered through an `unsigned`.
I'm looking to potentially add more bitfields to that `unsigned`, but I
find InlineAsm's big ol' bag of enum values and usage of `unsigned`
confusing, type-unsafe, and un-ergonomic. These can probably be better
abstracted.
I think the lack of static_cast outside of InlineAsm indicates the prior
code smell fixed here.
Reviewed By: qcolombet
Differential Revision: https://reviews.llvm.org/D159242
This reverts commit 8d0c3db388143f4e058b5f513a70fd5d089d51c3.
Causes crashes, see comments in https://reviews.llvm.org/D149367.
Some follow-up fixes are also reverted:
This reverts commit 636269f4fca44693bfd787b0a37bb0328ffcc085.
This reverts commit 5966079cf4d4de0285004eef051784d0d9f7a3a6.
This reverts commit e7294dbc85d24a08c716d9babbe7f68390cf219b.
This patch fixes:
llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp:3468:14: error:
variable 'foundJTI' set but not used
[-Werror,-Wunused-but-set-variable]
This patch fixes:
llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp:3540:9: error: default
label in switch which covers all enumeration values
[-Werror,-Wcovered-switch-default]
The CodeView `S_ARMSWITCHTABLE` debug symbol is used to describe the layout of a jump table, it contains the following information:
* The address of the branch instruction that uses the jump table.
* The address of the jump table.
* The "base" address that the values in the jump table are relative to.
* The type of each entry (absolute pointer, a relative integer, a relative integer that is shifted).
Together this information can be used by debuggers and binary analysis tools to understand what an jump table indirect branch is doing and where it might jump to.
Documentation for the symbol can be found in the Microsoft PDB library dumper: 0fe89a942f/cvdump/dumpsym7.cpp (L5518)
This change adds support to LLVM to emit the `S_ARMSWITCHTABLE` debug symbol as well as to dump it out (for testing purposes).
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D149367
With D149881, we converted EntryValue MachineFunction table entries into
`DbgVariables` initialized by a "DbgValue" intrinsic, which can only handle a
single, non-fragment DIExpression. However, it is desirable to handle variables
with multiple fragments and DIExpressions.
To do this, we expand the `DbgVariable` class to handle the EntryValue case.
This class can already operate under three different "modes" (stack slot,
unchanging location described by a dbg value, changing location described by a
loc list). A fourth case is added as a separate class entirely, but a subsequent
patch should redesign `DbgVariable` with four subclasses in order to make the
code more readable.
This patch also exposed a bug in the `beginEntryValueExpression` function, which
was not initializing the `LocationFlags` properly. Note how the
`finalizeEntryValue` function resets that flag. We fix this bug here, as testing
this changing in isolation would be tricky.
Differential Revision: https://reviews.llvm.org/D158458
When we convert an EntryValue dbg.declare into an entry of the MF side table, we
currently copy its DIExpression as is, and rely on subsequent layers to "know"
that this expression is implicitly indirect. This is bad because it adds an
implicit assumption to the IR representation, and requires subsequent layers to
know about this assumption. This also limits the reusability of this table:
what if, in the future, we want to use this table for dbg.values?
This patch changes existing behavior so that the entities converting
dbg_declares explicitly add an OP_deref when converting EntryValue dbg.declares.
Differential Revision: https://reviews.llvm.org/D158437
The class 'DbgVariable' can be in one of three states, and the "is any of them
initialization" logic for them is repeated in a couple of places. We may want to
expand this class in the future; as such, we factor out this common logic so
that it is easier to modify.
Differential Revision: https://reviews.llvm.org/D158438
1. In X86LowerAMXType.cpp dyn_cast could lead to UserI be nullptr which coud be dref in IRBuilder constructor.
2. In AsmPrinter.cpp, doInitialization could make MMI be nullptr if MMIWP->getMMI() is false, then the deref after could be unexpected.
Reviewed By: skan
Differential Revision: https://reviews.llvm.org/D157948
This reverts commit d20e4a1d68aa8e14c4e524e4d4eeb4445acac401.
After committing 2ee4d0386c783f58abe708298228de648239b435, We don't support subprogram definitions nested within `DICompositeType` when doing LTO builds.
For a detailed discussion, see https://reviews.llvm.org/D152095.
Entries of the same DJB hash are in the hash lookup table/name table are
ordered by the iteration order of `Entries` (a StringMap). Change
`Entries` to a MapVector to stabilize the order and simplify future
changes like D142862 that change the StringMap hash function.
The ELFObjectWriter::shouldRelocateWithSymbol change in D128958 is untested. Add
the testing.
Also, change a diagnostic to follow the convention (no capitalization or
trailing period). Test it.
This patch extends support of the option `-frecord-command-line` to XCOFF. XCOFF doesn’t have custom sections like ELF, so the command line data is emitted to a .info section instead. A C_INFO symbol is generated with the .info section to preserve the command line data past the link step. Multiple command lines are separated by newlines and null bytes. The command line data can be retrieved on AIX with command `what file_name`.
Reviewed By: scott.linder
Differential Revision: https://reviews.llvm.org/D153600
The DWARF 5 specification says that:
> All other debugging information entries without a DW_AT_name attribute are
> excluded.
Clang started generating these variables for string literals, see D123534.
Differential Revision: https://reviews.llvm.org/D153809
to help debug and report better diagnostics for functions like
relaxDwarfCallFrameFragment (D153167).
In MCStreamer, some emitCFI* functions already take a SMLoc argument. Add a
SMLoc argument to the remaining functions that generate a MCCFIInstruction.
In preparation for removing the `#include "llvm/ADT/StringExtras.h"`
from the header to source file of `llvm/Support/Error.h`, first add in
all the missing includes that were previously included transitively
through this header.
The `__DATA,xray_instr_map` section has label differences like
`.quad Lxray_sled_0-Ltmp0` that is represented as a pair of UNSIGNED and SUBTRACTOR relocations.
LLVM integrated assembler attempts to rewrite A-B into A-B'+offset where B' can
be included in the symbol table. B' is called an atom and should be a
non-temporary symbol in the same section. However, since `xray_instr_map` does
not define a non-temporary symbol, the SUBTRACTOR relocation will have no
associated symbol, and its `r_extern` value will be 0. Therefore, we will see
linker errors like:
error: SUBTRACTOR relocation must be extern at offset 0 of __DATA,xray_instr_map in a.o
To fix this issue, we need to define a non-temporary symbol in the section. We
can accomplish this by renaming `Lxray_sleds_start0` to `lxray_sleds_start0`
("L" to "l").
`lxray_sleds_start0` serves as the atom for this dead-strippable subsection.
With the `S_ATTR_LIVE_SUPPORT` attribute, `ld -dead_strip` will retain
subsections that reference live functions.
Special thanks to Oleksii Lozovskyi for reporting the issue and providing
initial analysis.
Differential Revision: https://reviews.llvm.org/D153239
As mentioned by commit c5d38924dc6688c15b3fa133abeb3626e8f0767c (Apr 2020),
PC-relative entries avoid dynamic relocations and can therefore make the
section read-only.
This is similar to D78082 and D78590. We cannot commit to support
compiler/runtime built at different versions, so just don't play with versions.
For Mach-O support (incomplete yet), we use non-temporary `lxray_fn_idx[0-9]+`
symbols. Label differences are represented as a pair of UNSIGNED and SUBTRACTOR
relocations. The SUBTRACTOR external relocation requires r_extern==1 (needs to
reference a symbol table entry) which can be satisfied by `lxray_fn_idx[0-9]+`.
A `lxray_fn_idx[0-9]+` symbol also serves as the atom for this dead-strippable
section (follow-up to commit b9a134aa629de23a1dcf4be32e946e4e308fc64d).
Differential Revision: https://reviews.llvm.org/D152661
D118754 added a new DICompileUnit::DebugNameTableKind for "Apple", so that,
under DWARF 5, the following combination is used inside DwarfDebug.cpp:
```
(lldb) p getAccelTableKind()
(llvm::AccelTableKind) $6 = Dwarf
(lldb) p CU.getNameTableKind()
(llvm::DICompileUnit::DebugNameTableKind) $7 = Apple
```
This creates a problem in the if statements changed, whereby "for non Apple
AccelTableKind" we emit empty tables for any DebugNameTableKind that is not
"Default". We should consider the newly added kind here too.
Note that our existing test could have caught this, if only it had checked the
_contents_ of the table, instead of merely checking for the existence of the
section.
Differential Revision: https://reviews.llvm.org/D153275
Test "local-type-as-template-parameter.ll" is now enabled only for
x86_64.
Authored-by: Kristina Bessonova <kbessonova@accesssoftek.com>
Differential Revision: https://reviews.llvm.org/D144006
Depends on D144005
The extension codespace for DWARF expressions (DW_OP_LLVM_{lo,hi}_user)
has shrunk over time, as no extension is ever "retired" in practice. To
facilitate future extensions, this patch reserves one open opcode as an extension
point (0xfe), which is followed by a ULEB128-encoded SubOperation, and
then by the subop's operands.
There is some prior-art, namely DW_OP_AARCH64_operation
(see edd7460d87/aadwarf64/aadwarf64.rst (45dwarf-expression-operations)).
This version makes some different tradeoffs, opting to use a ULEB128 for
the subop encoding for future-proofing.
Reviewed By: #debug-info, dblaikie
Differential Revision: https://reviews.llvm.org/D147271
Update DWARFExpression::Operation and LVOperation to support more than
2 operands.
Take the opportunity to use a SmallVector, which will handle at least 2
operands without allocation anyway, and removes the static limit
completely.
As there is no longer the concept of an "unused operand", remove
Operation::Encoding::SizeNA. Any use of it is now replaced with explicit
checks for how many operands an operation has.
There are still places where the limit remains 2, namely in the
DWARFLinker and in DIExpressions, but these can be updated in later
patches as-needed.
There are no explicit tests as this is nearly NFC: no new operation is
added which makes use of the additional operand capacity yet. A future
patch adding a new DWARF extension point will include operations which
require the support.
Reviewed By: Orlando, CarlosAlbertoEnciso
Differential Revision: https://reviews.llvm.org/D147270
Test "local-type-as-template-parameter.ll" now requires linux-system.
Authored-by: Kristina Bessonova <kbessonova@accesssoftek.com>
Differential Revision: https://reviews.llvm.org/D144006
Depends on D144005
Add the `S_ATTR_LIVE_SUPPORT` attribute to the sections so that `ld -dead_strip`
will retain subsections that reference live functions, once we we add linker
private "l" symbols as atoms.
This reverts commit d80fdc6fc1a6e717af1bcd7a7313e65de433ba85.
split-dwarf-local-impor3.ll fails because of an issue with
Dwo sections emission on Windows platform.
RFC https://discourse.llvm.org/t/rfc-dwarfdebug-fix-and-improve-handling-imported-entities-types-and-static-local-in-subprogram-and-lexical-block-scopes/68544
Fixed PR51501 (tests from D112337).
1. Reuse of DISubprogram's 'retainedNodes' to track other function-local
entities together with local variables and labels (this patch cares about
function-local import while D144006 and D144008 use the same approach for
local types and static variables). So, effectively this patch moves ownership
of tracking local import from DICompileUnit's 'imports' field to DISubprogram's
'retainedNodes' and adjusts DWARF emitter for the new layout. The old layout
is considered unsupported (DwarfDebug would assert on such debug metadata).
DICompileUnit's 'imports' field is supposed to track global imported
declarations as it does before.
This addresses various FIXMEs and simplifies the next part of the patch.
2. Postpone emission of function-local imported entities from
`DwarfDebug::endFunctionImpl()` to `DwarfDebug::endModule()`.
While in `DwarfDebug::endFunctionImpl()` we do not have all the
information about a parent subprogram or a referring subprogram
(whether a subprogram inlined or not), so we can't guarantee we emit
an imported entity correctly and place it in a proper subprogram tree.
So now, we just gather needed details about the import itself and its
parent entity (either a Subprogram or a LexicalBlock) during
processing in `DwarfDebug::endFunctionImpl()`, but all the real work is
done in `DwarfDebug::endModule()` when we have all the required
information to make proper emission.
Authored-by: Kristina Bessonova <kbessonova@accesssoftek.com>
Differential Revision: https://reviews.llvm.org/D144004
This reverts commit ed578f02cf44a52adde16647150e7421f3ef70f3.
Tests llvm/test/DebugInfo/Generic/split-dwarf-local-import*.ll fail
when x86_64 target is not registered.
RFC https://discourse.llvm.org/t/rfc-dwarfdebug-fix-and-improve-handling-imported-entities-types-and-static-local-in-subprogram-and-lexical-block-scopes/68544
Fixed PR51501 (tests from D112337).
1. Reuse of DISubprogram's 'retainedNodes' to track other function-local
entities together with local variables and labels (this patch cares about
function-local import while D144006 and D144008 use the same approach for
local types and static variables). So, effectively this patch moves ownership
of tracking local import from DICompileUnit's 'imports' field to DISubprogram's
'retainedNodes' and adjusts DWARF emitter for the new layout. The old layout
is considered unsupported (DwarfDebug would assert on such debug metadata).
DICompileUnit's 'imports' field is supposed to track global imported
declarations as it does before.
This addresses various FIXMEs and simplifies the next part of the patch.
2. Postpone emission of function-local imported entities from
`DwarfDebug::endFunctionImpl()` to `DwarfDebug::endModule()`.
While in `DwarfDebug::endFunctionImpl()` we do not have all the
information about a parent subprogram or a referring subprogram
(whether a subprogram inlined or not), so we can't guarantee we emit
an imported entity correctly and place it in a proper subprogram tree.
So now, we just gather needed details about the import itself and its
parent entity (either a Subprogram or a LexicalBlock) during
processing in `DwarfDebug::endFunctionImpl()`, but all the real work is
done in `DwarfDebug::endModule()` when we have all the required
information to make proper emission.
Authored-by: Kristina Bessonova <kbessonova@accesssoftek.com>
Differential Revision: https://reviews.llvm.org/D144004
RFC https://discourse.llvm.org/t/rfc-dwarfdebug-fix-and-improve-handling-imported-entities-types-and-static-local-in-subprogram-and-lexical-block-scopes/68544
Fixed PR51501 (tests from D112337).
1. Reuse of DISubprogram's 'retainedNodes' to track other function-local
entities together with local variables and labels (this patch cares about
function-local import while D144006 and D144008 use the same approach for
local types and static variables). So, effectively this patch moves ownership
of tracking local import from DICompileUnit's 'imports' field to DISubprogram's
'retainedNodes' and adjusts DWARF emitter for the new layout. The old layout
is considered unsupported (DwarfDebug would assert on such debug metadata).
DICompileUnit's 'imports' field is supposed to track global imported
declarations as it does before.
This addresses various FIXMEs and simplifies the next part of the patch.
2. Postpone emission of function-local imported entities from
`DwarfDebug::endFunctionImpl()` to `DwarfDebug::endModule()`.
While in `DwarfDebug::endFunctionImpl()` we do not have all the
information about a parent subprogram or a referring subprogram
(whether a subprogram inlined or not), so we can't guarantee we emit
an imported entity correctly and place it in a proper subprogram tree.
So now, we just gather needed details about the import itself and its
parent entity (either a Subprogram or a LexicalBlock) during
processing in `DwarfDebug::endFunctionImpl()`, but all the real work is
done in `DwarfDebug::endModule()` when we have all the required
information to make proper emission.
Authored-by: Kristina Bessonova <kbessonova@accesssoftek.com>
Differential Revision: https://reviews.llvm.org/D144004
