This change enables emitting CFI unwind information for debugging purpose
for targets with MCAsmInfo::ExceptionsType == ExceptionHandling::None.
Currently generating CFI unwind information is entangled with supporting
the exceptions, even when AsmPrinter explicitly recognizes that the unwind
tables are being generated as debug information.
In fact, the unwind information is not generated even if we specify
--force-dwarf-frame-section, unless exceptions are enabled. The LIT test
llvm/test/CodeGen/AMDGPU/debug_frame.ll demonstrates this behavior.
Enable this option for AMDGPU to prepare for future patches which add
complete CFI support.
Reviewed By: dblaikie, MaskRay
Differential Revision: https://reviews.llvm.org/D78778
This untangles the MCContext and the MCObjectFileInfo. There is a circular
dependency between MCContext and MCObjectFileInfo. Currently this dependency
also exists during construction: You can't contruct a MOFI without a MCContext
without constructing the MCContext with a dummy version of that MOFI first.
This removes this dependency during construction. In a perfect world,
MCObjectFileInfo wouldn't depend on MCContext at all, but only be stored in the
MCContext, like other MC information. This is future work.
This also shifts/adds more information to the MCContext making it more
available to the different targets. Namely:
- TargetTriple
- ObjectFileType
- SubtargetInfo
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D101462
- As per the HLASM support we are providing, i.e. support only for the first parameter of the inline asm block, only pertaining to Z machine instructions defined in LLVM, character literals and string literals are not supported (see Figure 4 - https://www-01.ibm.com/servers/resourcelink/svc00100.nsf/pages/zOSV2R3sc264940/$file/asmr1023.pdf for more information)
- This patch explicitly rejects the usage of char literals and string literals (for example "abc 'a'") when the relevant field is set
- This is achieved by introducing a field called `LexHLASMStrings` in MCAsmLexer similar to `LexMasmStrings`
Reviewed By: abhina.sreeskantharajan, Kai
Differential Revision: https://reviews.llvm.org/D101660
- This patch attempts to implement the location counter syntax (*) for the HLASM variant for PC-relative instructions.
- In the HLASM variant, for purely constant relocatable values, we expect a * token preceding it, with special support for " *" which is parsed as "<pc-rel-insn 0>"
- For combinations of absolute values and relocatable values, we don't expect the "*" preceding the token.
When you have a " * " what’s accepted is:
```
*<space>.*{.*} -> <pc-rel-insn> 0
*[+|-][constant-value] -> <pc-rel-insn> [+|-]constant-value
```
When you don’t have a " * " what’s accepted is:
```
brasl 1,func is allowed (MCSymbolRef type)
brasl 1,func+4 is allowed (MCBinary type)
brasl 1,4+func is allowed (MCBinary type)
brasl 1,-4+func is allowed (MCBinary type)
brasl 1,func-4 is allowed (MCBinary type)
brasl 1,*func is not allowed (* cannot be used for non-MCConstantExprs)
brasl 1,*+func is not allowed (* cannot be used for non-MCConstantExprs)
brasl 1,*+func+4 is not allowed (* cannot be used for non-MCConstantExprs)
brasl 1,*+4+func is not allowed (* cannot be used for non-MCConstantExprs)
brasl 1,*-4+8+func is not allowed (* cannot be used for non-MCConstantExprs)
```
Reviewed By: Kai
Differential Revision: https://reviews.llvm.org/D100987
- Add new variantKinds for the symbol's variable offset and region handle
- Print the proper relocation specifier @gd in the asm streamer when emitting
the TC Entry for the variable offset for the symbol
- Fix the switch section failure between the TC Entry of variable offset and
region handle
- Put .__tls_get_addr symbol in the ProgramCodeSects with XTY_ER property
Reviewed by: sfertile
Differential Revision: https://reviews.llvm.org/D100956
- Currently, the "." (Dot) character, when not identifying an Identifier or a Constant, refers to the current PC (Program Counter)
- However, in z/OS, for the HLASM dialect, it strictly accepts only the "*" as the current PC (Support for this will be put up in a follow-up patch)
- The changes in this patch allow individual platforms to choose whether they would like to use the "." (Dot) character as a marker for the current PC or not.
- It is achieved by introducing a new field in MCAsmInfo.h called `DotIsPC` (similar to `DollarIsPC`)
Reviewed By: abhina.sreeskantharajan
Differential Revision: https://reviews.llvm.org/D100975
- Previously, https://reviews.llvm.org/D99889 changed the framework in the AsmLexer to treat special tokens, if they occur at the start of the string, as Identifiers.
- These are used by the MASM Parser implementation in LLVM, and we can extend some of the changes made in the previous patch to SystemZ.
- In SystemZ, the special "tokens" referred to here are "_", "$", "@", "#". [_|$|@|#] are already supported as "part" of an Identifier.
- The changes in this patch ensure that these special tokens, when they occur at the start of the Identifier, are treated as Identifiers.
Reviewed By: abhina.sreeskantharajan
Differential Revision: https://reviews.llvm.org/D100959
The .file directive is changed to only have basename in D36018 for
ELF.
But on AIX, we require the .file directive to also contain the
directory info. This aligns with other AIX compiler like XLC and is
required by some AIX tool like DBX.
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D99785
1. Add an accessor function to MCSymbolizer to retrieve addresses
referenced by a symbolizable operand, but not resolved to a symbol.
That way, the caller can synthesize labels at those addresses and
then retry disassembling the section.
2. Implement that in AMDGPU -- a failed symbol lookup results in the
address being added to a vector returned by the new function.
3. Use that in llvm-objdump when using MCSymbolizer (which only happens
on AMDGPU) and SymbolizeOperands is on.
Differential Revision: https://reviews.llvm.org/D101145
Change-Id: I19087c3bbfece64bad5a56ee88bcc9110d83989e
Report dangling probes for frames that have real samples collected. Dangling probes are the probes associated to an empty block. When reported, sample count on a dangling probe will not be trusted by the compiler and we will rely on the counts inference algorithm to get the probe a reasonable count. This actually fixes a bug where previously only those dangling probes with samples collected were reported.
This patch also fixes two existing issues. Pseudo probes are stored in `Address2ProbesMap` and their pointers are used in `PseudoProbeInlineTree`. Previously `std::vector` was used to store probes and the pointers to probes may get obsolete as the vector grows. I'm changing `std::vector` to `std::list` instead.
The other issue is that all outlined functions shared the same inline frame previously due to the unchanged `Index` value as the dummy inlineSite identifier.
Good results seen for SPEC2017 in general regarding profile quality.
Reviewed By: wenlei, wlei
Differential Revision: https://reviews.llvm.org/D100235
- Previously, https://reviews.llvm.org/D72680 introduced a new attribute called `AllowSymbolAtNameStart` (in relation to the MAsmParser changes) in `MCAsmInfo.h` which (according to the comment in the header) allows the following behaviour:
```
/// This is true if the assembler allows $ @ ? characters at the start of
/// symbol names. Defaults to false.
```
- However, the usage of this field in AsmLexer.cpp doesn't seem completely accurate* for a couple of reasons.
```
default:
if (MAI.doesAllowSymbolAtNameStart()) {
// Handle Microsoft-style identifier: [a-zA-Z_$.@?][a-zA-Z0-9_$.@#?]*
if (!isDigit(CurChar) &&
isIdentifierChar(CurChar, MAI.doesAllowAtInName(),
AllowHashInIdentifier))
return LexIdentifier();
}
```
1. The Dollar and At tokens, when occurring at the start of the string, are treated as separate tokens (AsmToken::Dollar and AsmToken::At respectively) and not lexed as an Identifier.
2. I'm not too sure why `MAI.doesAllowAtInName()` is used when `AllowAtInIdentifier` could be used. For X86 platforms, afaict, this shouldn't be an issue, since the `CommentString` attribute isn't "@". (alternatively the call to the setter can be set anywhere else as needed). The `AllowAtInName` does have an additional important meaning, but in the context of AsmLexer, shouldn't mean anything different compared to `AllowAtInIdentifier`
My proposal is the following:
- Introduce 3 new fields called `AllowQuestionTokenAtStartOfString`, `AllowDollarTokenAtStartOfString` and `AllowAtTokenAtStartOfString` in MCAsmInfo.h which will encapsulate the previously documented behaviour of "allowing $, @, ? characters at the start of symbol names")
- Introduce these fields where "$", "@" are lexed, and treat them as identifiers depending on whether `Allow[Dollar|At]TokenAtStartOfString` is set.
- For the sole case of "?", append it to the existing logic for treating a "default" token as an Identifier.
z/OS (HLASM) will also make use of some of these fields in follow up patches.
completely accurate* - This was based on the comments and the intended behaviour the code. I might have completely misinterpreted it, and if that is the case my sincere apologies. We can close this patch if necessary, if there are no changes to be made :)
Depends on https://reviews.llvm.org/D99374
Reviewed By: Jonathan.Crowther
Differential Revision: https://reviews.llvm.org/D99889
- Add support for HLASM style integers. These are the decimal integers [0-9].
- HLASM does not support the additional prefixed integers like, `0b`, `0x`, octal integers and Masm style integers.
- To achieve this, a field `LexHLASMStyleIntegers` (similar to the `LexMasmStyleIntegers` field) is introduced in `MCAsmLexer.h` as well as a corresponding setter.
Note: This field could also go into MCAsmInfo.h. I used the previous precedent set by the `LexMasmIntegers` field.
Depends on https://reviews.llvm.org/D99286
Reviewed By: epastor
Differential Revision: https://reviews.llvm.org/D99374
- Currently, MCAsmInfo provides a CommentString attribute, that various targets can set, so that the AsmLexer can appropriately lex a string as a comment based on the set value of the attribute.
- However, AsmLexer also supports a few additional comment syntaxes, in addition to what's specified as a CommentString attribute. This includes regular C-style block comments (/* ... */), regular C-style line comments (// .... ) and #. While I'm not sure as to why this behaviour exists, I am assuming it does to maintain backward compatibility with GNU AS (see https://sourceware.org/binutils/docs/as/Comments.html#Comments for reference)
For example:
Consider a target which sets the CommentString attribute to '*'.
The following strings are all lexed as comments.
```
"# abc" -> comment
"// abc" -> comment
"/* abc */ -> comment
"* abc" -> comment
```
- In HLASM however, only "*" is accepted as a comment string, and nothing else.
- To achieve this, an additional attribute (`AllowAdditionalComments`) has been added to MCAsmInfo. If this attribute is set to false, then only the string specified by the CommentString attribute is used as a possible comment string to be lexed by the AsmLexer. The regular C-style block comments, line comments and "#" are disabled. As a final note, "#" will still be treated as a comment, if the CommentString attribute is set to "#".
Depends on https://reviews.llvm.org/D99277
Reviewed By: abhina.sreeskantharajan, myiwanch
Differential Revision: https://reviews.llvm.org/D99286
These look like $00A0cf for hex and %001010101 for binary. They are used in Motorola assembly syntax.
Differential Revision: https://reviews.llvm.org/D98519
- This patch adds in support to accept the "#" character as part of an Identifier.
- This support is needed especially for the HLASM dialect since "#" is treated as part of the valid "Alphabet" range
- The way this is done is by making use of the previous precedent set by the `AllowAtInIdentifier` field in `MCAsmLexer.h`. A new field called `AllowHashInIdentifier` is introduced.
- The static function `IsIdentifierChar` is also updated to accept the `#` character if the `AllowHashInIdentifier` field is set to true.
Note: The field introduced in `MCAsmLexer.h` could very well be moved to `MCAsmInfo.h`. I'm not opposed to it. I decided to put it in `MCAsmLexer` since there seems to be some sort of precedent already with `AllowAtInIdentifier`.
Reviewed By: abhina.sreeskantharajan, nickdesaulniers, MaskRay
Differential Revision: https://reviews.llvm.org/D99277
- https://reviews.llvm.org/rGb605cfb336989705f391d255b7628062d3dfe9c3 was reverted due to sanitizer bugs in the introduced unit-test (specifically in the Address sanitizer https://lab.llvm.org/buildbot/#/builders/5/builds/5697)
- This patch attempts to rectify that, as well as re-factor parts of the test
- The issue was previously, within the `setupCallToAsmParser` function in the unit-test, `SrcMgr` was declared as a local variable. `SrcMgr` owns a unique pointer. Since the variable goes out of scope at the end of the function, the unique pointer is released.
- This patch, moves the declaration of the `SrcMgr` variable to a class field, since the scope will remain until the class's destructor is invoked (which in this case is at the end of the unit test)
- Furthermore, this patch also moves the `MCContext Ctx` declaration from a local variable instance inside a function, to a unique pointer class field. This ensures the instantiation of the MCContext remains until the tear down of the test.
Reviewed By: abhina.sreeskantharajan
Differential Revision: https://reviews.llvm.org/D99004
This commit adds a full WasmTableType to MCSymbolWasm, differing from
the current situation (just an ElemType) in that it additionally records
a WasmLimits.
We add support for specifying the limits in .S files also, via the
following syntax variations:
.tabletype SYM, ELEMTYPE
.tabletype SYM, ELEMTYPE, MINSIZE
.tabletype SYM, ELEMTYPE, MINSIZE, MAXSIZE
Depends on D99186.
Differential Revision: https://reviews.llvm.org/D99191
This patch addresses the removal of register size information done in
commit c8b782c.
Without this change, there is no viable option to get register size
information outside libTarget. We need this information to run
analysis that know the register size from the MC layer, used by
BOLT.
Discussion D50285 and D47199.
Reviewed By: kparzysz
Differential Revision: https://reviews.llvm.org/D97891
This is the alternative approach to D96931.
In LTO, for each module with inlineasm block, prepend directive ".lto_discard <sym>, <sym>*" to the beginning of the inline
asm. ".lto_discard" is both a module inlineasm block marker and (optionally) provides a list of symbols to be discarded.
In MC while emitting for inlineasm, discard symbol binding & symbol
definitions according to ".lto_disard".
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D98762
- Previously, https://reviews.llvm.org/D97703 was [[ https://reviews.llvm.org/D98543 | reverted ]] as it broke when building the unit tests when shared libs on.
- This patch reverts the "revert" and makes two minor changes
- The first is it also links in the MCParser lib when building the unittest. This should resolve the issue when building with with shared libs on and off
- The second renames the name of the unit test from `SystemZAsmLexer` to `SystemZAsmLexerTests` since the convention for unittest binaries is to suffix the name of the unit test with "Tests"
Reviewed By: Kai
Differential Revision: https://reviews.llvm.org/D98666
- This patch adds in support for the ordinary HLASM comment syntax asm
statements (Reference - Chapter 7, Comment Statements, Ordinary Comment
Statements)
- In brief, the ordinary comment syntax if used, must begin with the "*"
character
- To achieve this, this patch makes use of the CommentString attribute
provided in the base MCAsmInfo class
- In the SystemZMCAsmInfo class, the CommentString attribute was set to
"*" based on the assembler dialect
- Furthermore, a new attribute RestrictCommentString, is provided to only
treat a string as a comment if it appears at the start of the asm
statement. Example: "jo *-4" is valid in HLASM (jump back 4 bytes from
current point - similar to jo -4 in gnu asm) and we don't want "*-4" to
be treated as a comment.
- RFC for HLASM Parser support implementation: https://lists.llvm.org/pipermail/llvm-dev/2021-January/147686.html
Reviewed By: scott.linder, Kai
Differential Revision: https://reviews.llvm.org/D97703
This patch adds the assert check inside the constructor for the csect (MCSectionXCOFF) to ensure
valid csect type used for the storage mappping class XCOFF:XMC_UL.
This `R_WASM_MEMORY_ADDR_SELFREL_I32` relocation represents an offset
between its relocating address and the symbol address. It's very similar
to `R_X86_64_PC32` but restricted to be used for only data segments.
```
S + A - P
```
A: Represents the addend used to compute the value of the relocatable
field.
P: Represents the place of the storage unit being relocated.
S: Represents the value of the symbol whose index resides in the
relocation entry.
Proposal: https://github.com/WebAssembly/tool-conventions/issues/162
Differential Revision: https://reviews.llvm.org/D96659
For many directives, the following diagnostics
* `error: unexpected token`
* `error: unexpected token in '.abort' directive"`
are replaced with `error: expected newline`.
`unexpected token` may make the user think a different token is needed.
`expected newline` is clearer about the expected token.
For `in '...' directive`, the directive name is not useful because the next line
replicates the error line which includes the directive.
As a resolution to https://sourceware.org/bugzilla/show_bug.cgi?id=25295 , GNU as
from binutils 2.35 supports the optional third argument for the .symver directive.
'remove' for a non-default version is useful:
`.symver def_v1, def@v1, remove` => def_v1 is not retained in the symbol table.
Previously the user has to strip the original symbol or specify a `local:`
version node in a version script to localize the symbol.
`.symver def, def@@v1, remove` and `.symver def, def@@@v1, remove` are supported
as well, though they are identical to `.symver def, def@@@v1`.
local/hidden are not useful so this patch does not implement them.
This patch adds a pipeline to support in-order CPUs such as ARM
Cortex-A55.
In-order pipeline implements a simplified version of Dispatch,
Scheduler and Execute stages as a single stage. Entry and Retire
stages are common for both in-order and out-of-order pipelines.
Differential Revision: https://reviews.llvm.org/D94928
Dangling probes are the probes associated to an empty block. This usually happens when all real instructions are optimized away from the block. There is a problem with dangling probes during the offline counts processing. The way the sample profiler works is that samples collected on the first physical instruction following a probe will be counted towards the probe. This logically equals to treating the instruction next to a probe as if it is from the same block of the probe. In the dangling probe case, the real instruction following a dangling probe actually starts a new block, and samples collected on the new block may cause issues when counted towards the empty block.
To mitigate this issue, we first try to move around a dangling probe inside its owning block. If there are still native instructions preceding the probe in the same block, we can then use them as a place holder to collect samples for the probe. A pass is added to walk each block backwards looking for probes not followed by any real instruction and moving them before the first real instruction. This is done right before the object emission.
If we are unlucky to find such in-block preceding instructions for a probe, the solution we are taking is to tag such probe as dangling so that the samples reported for them will not be trusted by the compiler. We leave it up to the counts inference algorithm to get such probes a reasonable count. The number `UINT64_MAX` is used to mark sample count as collected for a dangling probe.
Reviewed By: wmi
Differential Revision: https://reviews.llvm.org/D95962
This patch allows generating TLS variables in assembly files on AIX.
Initialized and external uninitialized variables are generated with the
.csect pseudo-op and local uninitialized variables are generated with
the .comm/.lcomm pseudo-ops. The patch also adds a check to
explicitly say that TLS is not yet supported on AIX.
Reviewed by: daltenty, jasonliu, lei, nemanjai, sfertile
Originally patched by: bsaleil
Commandeered by: NeHuang
Differential Revision: https://reviews.llvm.org/D96184
The situation with inline asm/MC error reporting is kind of messy at the
moment. The errors from MC layout are not reliably propagated and users
have to specify an inlineasm handler separately to get inlineasm
diagnose. The latter issue is not a correctness issue but could be improved.
* Kill LLVMContext inlineasm diagnose handler and migrate it to use
DiagnoseInfo/DiagnoseHandler.
* Introduce `DiagnoseInfoSrcMgr` to diagnose SourceMgr backed errors. This
covers use cases like inlineasm, MC, and any clients using SourceMgr.
* Move AsmPrinter::SrcMgrDiagInfo and its instance to MCContext. The next step
is to combine MCContext::SrcMgr and MCContext::InlineSrcMgr because in all
use cases, only one of them is used.
* If LLVMContext is available, let MCContext uses LLVMContext's diagnose
handler; if LLVMContext is not available, MCContext uses its own default
diagnose handler which just prints SMDiagnostic.
* Change a few clients(Clang, llc, lldb) to use the new way of reporting.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D97449
If the reference-types feature is enabled, call_indirect will explicitly
reference its corresponding function table via TABLE_NUMBER
relocations against a table symbol.
Also, as before, address-taken functions can also cause the function
table to be created, only with reference-types they additionally cause a
symbol table entry to be emitted.
Differential Revision: https://reviews.llvm.org/D90948
remove `Hi` `Lo` argument from `emitDwarfUnitLength`, so we
can make caller of emitDwarfUnitLength easier.
Reviewed By: MaskRay, dblaikie, ikudrin
Differential Revision: https://reviews.llvm.org/D96409
We may need to do some customization for DWARF unit length in DWARF
section headers for some targets for some code generation path.
For example, for XCOFF in assembly path, AIX assembler does not require
the debug section containing its debug unit length in the header.
Move emitDwarfUnitLength to MCStreamer class so that we can do
customization in different Streamers
Reviewed By: ikudrin
Differential Revision: https://reviews.llvm.org/D95932
If the reference-types feature is enabled, call_indirect will explicitly
reference its corresponding function table via `TABLE_NUMBER`
relocations against a table symbol.
Also, as before, address-taken functions can also cause the function
table to be created, only with reference-types they additionally cause a
symbol table entry to be emitted.
We abuse the used-in-reloc flag on symbols to indicate which tables
should end up in the symbol table. We do this because unfortunately
older wasm-ld will carp if it see a table symbol.
Differential Revision: https://reviews.llvm.org/D90948
This patch makes StorageMappingClass/SymbolType member optional in
class MCSectionXCOFF.
Non-csect sections like debug sections have no such properties.
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D96641
We are going to support debug sections for XCOFF. So the csect
properties are not necessary. This patch makes these properties
optional.
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D95931
Otherwise they are not allocated as a single bit field and take 4
bytes instead of 2.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D95954
This change introduces support for zero flag ELF section groups to LLVM.
LLVM already supports COMDAT sections, which in ELF are a special type
of ELF section groups. These are generally useful to enable linker GC
where you want a group of sections to always travel together, that is to
be either retained or discarded as a whole, but without the COMDAT
semantics. Other ELF assemblers already support zero flag ELF section
groups and this change helps us reach feature parity.
Differential Revision: https://reviews.llvm.org/D95851
In the future Windows will enable Control-flow Enforcement Technology (CET aka shadow stacks). To protect the path where the context is updated during exception handling, the binary is required to enumerate valid unwind entrypoints in a dedicated section which is validated when the context is being set during exception handling.
This change allows llvm to generate the section that contains the appropriate symbol references in the form expected by the msvc linker.
This feature is enabled through a new module flag, ehcontguard, which was modelled on the cfguard flag.
The change includes a test that when the module flag is enabled the section is correctly generated.
The set of exception continuation information includes returns from exceptional control flow (catchret in llvm).
In order to collect catchret we:
1) Includes an additional flag on machine basic blocks to indicate that the given block is the target of a catchret operation,
2) Introduces a new machine function pass to insert and collect symbols at the start of each block, and
3) Combines these targets with the other EHCont targets that were already being collected.
Change originally authored by Daniel Frampton <dframpto@microsoft.com>
For more details, see MSVC documentation for `/guard:ehcont`
https://docs.microsoft.com/en-us/cpp/build/reference/guard-enable-eh-continuation-metadata
Reviewed By: pengfei
Differential Revision: https://reviews.llvm.org/D94835
References to functions are in program memory and need a `pm()` fixup. This should fix trait objects for Rust on AVR.
Differential Revision: https://reviews.llvm.org/D87631
Patch by Alex Mikhalev.
