- Add branch absolute reloction R_RBA, R_TLS relocation for the variable offset
for the tlsgd model and R_TLSM for the region handle for the tlsgd model
- Properly set the relocation fixed values for R_TLS and R_TLSM
- Emit the TCEntry with the variant kind in the XCOFFStreamer
Reviewed by: sfertile, nemanjai, DiggerLin
Differential Revision: https://reviews.llvm.org/D100214
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 fixes PR49821, and avoids "ld.lld: error: test.o:(.rodata.str1.1):
offset is outside the section" errors when linking MIPS objects with
negative R_MIPS_LO16 implicit addends.
ld.lld handles R_MIPS_HI16/R_MIPS_LO16 separately, not as a whole, so it
doesn't know that an R_MIPS_HI16 with implicit addend 1 and an
R_MIPS_LO16 with implicit addend -32768 represents 32768, which is in
range of a MergeInputSection. We could introduce a new RelExpr member
(like R_RISCV_PC_INDIRECT for R_RISCV_PCREL_HI20 / R_RISCV_PCREL_LO12)
but the complexity is unnecessary given that GNU as keeps the original
symbol for this case as well.
Adds a new test case for PR49821, and also updates two other test cases
that are affected by this change.
Reviewed By: atanasyan, MaskRay
Differential Revision: https://reviews.llvm.org/D101773
This reverts commit ab40c027f0.
Some additional test cases are influenced by the workaround, and I need
to do a complete test run to identify and check them all.
This fixes PR49821, and avoids "ld.lld: error: test.o:(.rodata.str1.1):
offset is outside the section" errors when linking MIPS objects with
negative R_MIPS_LO16 implicit addends.
ld.lld handles R_MIPS_HI16/R_MIPS_LO16 separately, not as a whole, so it
doesn't know that an R_MIPS_HI16 with implicit addend 1 and an
R_MIPS_LO16 with implicit addend -32768 represents 32768, which is in
range of a MergeInputSection. We could introduce a new RelExpr member
(like R_RISCV_PC_INDIRECT for R_RISCV_PCREL_HI20 / R_RISCV_PCREL_LO12)
but the complexity is unnecessary given that GNU as keeps the original
symbol for this case as well.
Reviewed By: atanasyan, MaskRay
Differential Revision: https://reviews.llvm.org/D101773
- 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
Summary:
This patch implements the backend implementation of adding global variables
directly to the table of contents (TOC), rather than adding the address of the
variable to the TOC.
Currently, this patch will look for the "toc-data" attribute on symbols in the
IR, and then add those symbols to the TOC.
ATM, this is implemented for 32 bit AIX.
Reviewers: sfertile
Differential Revision: https://reviews.llvm.org/D101178
- 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
- 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
The GNU AS manual states the following about single-character constants enclosed within single quotes:
> Some backslash escapes apply to characters, \b, \f, \n, \r, \t, and \" with the same meaning as for strings, plus \' for a single quote.
Add two more characters to the switch handling this case to match GAS behaviour, plus a test to make sure nothing regresses.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D99609
Use report_fatal_error here since this is an internal error, and not
something the user can/should be trying to fix.
Also distinguish between the symbol being missing and the symbol having
the wrong type.
We have a failure internally where the symbol is missing. Currently
trying to reduce the test case to something we can attach to an llvm
bug.
Differential Revision: https://reviews.llvm.org/D99960
This patch adds support for TLS variables to the XCOFF object writer:
- Add TData and TBSS sections
- Add CsectGroups for the mapping classes XCOFF::XMC_TL and XCOFF::XMC_UL
- Add XMC_UL in the enum entry of CsectStorageMapping class to print the string
while reading the symbol properties for TLS variables
- Fix the starting address of TData and TBSS sections
Reviewed by: hubert.reinterpretcast, DiggerLin
Differential Revision: https://reviews.llvm.org/D98946
Problem:
On SystemZ we need to open text files in text mode. On Windows, files opened in text mode adds a CRLF '\r\n' which may not be desirable.
Solution:
This patch adds two new flags
- OF_CRLF which indicates that CRLF translation is used.
- OF_TextWithCRLF = OF_Text | OF_CRLF indicates that the file is text and uses CRLF translation.
Developers should now use either the OF_Text or OF_TextWithCRLF for text files and OF_None for binary files. If the developer doesn't want carriage returns on Windows, they should use OF_Text, if they do want carriage returns on Windows, they should use OF_TextWithCRLF.
So this is the behaviour per platform with my patch:
z/OS:
OF_None: open in binary mode
OF_Text : open in text mode
OF_TextWithCRLF: open in text mode
Windows:
OF_None: open file with no carriage return
OF_Text: open file with no carriage return
OF_TextWithCRLF: open file with carriage return
The Major change is in llvm/lib/Support/Windows/Path.inc to only set text mode if the OF_CRLF is set.
```
if (Flags & OF_CRLF)
CrtOpenFlags |= _O_TEXT;
```
These following files are the ones that still use OF_Text which I left unchanged. I modified all these except raw_ostream.cpp in recent patches so I know these were previously in Binary mode on Windows.
./llvm/lib/Support/raw_ostream.cpp
./llvm/lib/TableGen/Main.cpp
./llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
./llvm/unittests/Support/Path.cpp
./clang/lib/StaticAnalyzer/Core/HTMLDiagnostics.cpp
./clang/lib/Frontend/CompilerInstance.cpp
./clang/lib/Driver/Driver.cpp
./clang/lib/Driver/ToolChains/Clang.cpp
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D99426
These look like $00A0cf for hex and %001010101 for binary. They are used in Motorola assembly syntax.
Differential Revision: https://reviews.llvm.org/D98519
Define -fatal-warnings to make warnings fatal, and accept /WX as an ML.EXE compatible alias for it.
Also make sure that if Warning() returns true, we always treat it as an error.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D92504
Make variables and text-macro references case-insensitive, to match ml.exe.
Also improve error handling for text-macro expansion.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D92503
- 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 renames the "Initial" member of WasmLimits to the name used
in the spec, "Minimum".
In the core WebAssembly specification, the Limits data type has one
required "min" member and one optional "max" member, indicating the
minimum required size of the corresponding table or memory, and the
maximum size, if any.
Although the WebAssembly spec does instantiate locally-defined tables
and memories with the initial size being equal to the minimum size, it
can't impose such a requirement for imports. It doesn't make sense to
require an initial size for a memory import, for example. The compiler
can only sensibly express the minimum and maximum sizes.
See
https://github.com/WebAssembly/js-types/blob/master/proposals/js-types/Overview.md#naming-of-size-limits
for a related discussion that agrees that the right name of "initial" is
"minimum" when querying the type of a table or memory from JavaScript.
(Of course it still makes sense for JS to speak in terms of an initial
size when it explicitly instantiates memories and tables.)
Differential Revision: https://reviews.llvm.org/D99186
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
Summary: This is a minor patch to add names for the debug line prologue, as a follow-up of D95998.
Reviewed By: dblaikie, ikudrin, shchenz
Differential Revision: https://reviews.llvm.org/D98383
A symbol being redefined as a label is something that can happen as a result of
ordinary input, so it shouldn't cause a fatal error. Also adjust the error
message to match the one you get when a symbol is redefined as a variable.
Differential Revision: https://reviews.llvm.org/D98181
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.
With reference types, tables can have non-zero table numbers. This
commit adds support for element sections against these tables.
Differential Revision: https://reviews.llvm.org/D97923
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
Use emitDwarfUnitLength for debug line, so we can benefit from
overriding of emitDwarfUnitLength inside different streamers.
Reviewed By: ikudrin, dblaikie
Differential Revision: https://reviews.llvm.org/D95998
GNU as supports this. This mode silently ignores
.cfi_startproc/.cfi_endproc and .cfi_* in between.
Also drop a diagnostic `in '.cfi_sections' directive`: the diagnostic
already includes the line and it is clear the line is a `.cfi_sections` directive.
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
This is for XCOFF DWARF support.
Seems when DWARF debug is enable, symbol 0 has special usage
for AIX binder. At least, symbol 0 can not be the .text
section. Otherwise, we get some binding time error.
Add correct C_FILE symbol at index 0 here to make AIX binder
work.
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D97117
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
Fixes assert in: https://bugs.llvm.org/show_bug.cgi?id=49036
getWasmSection creates sections if they don't exist, but doesn't add them to the Symbols table. This may cause problems in subsequent calls to getOrCreateSymbol which checks this table, the calls createSymbol assuming it doesn't exist, which then checks UsedNames and finds out it does exist, causing an assert on trying to rename a non-temp symbol.
I tried also fixing the somewhat unintuitive forced suffixing (adding `0`), but it turns out that WasmObjectWriter currently assumes these section symbols are unique, so that may have to be a separate fix: https://bugs.llvm.org/show_bug.cgi?id=49252
Also worth noting is that getWasmSection calling createSymbol may not be correct to start with, given that createSymbol seems to assume it is creating non-section symbols. But again, for a future fix.
Related: where some of this was introduced: 8d396acac3
Differential Revision: https://reviews.llvm.org/D96473
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
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
As we don't sort local symbols, don't sort non-local symbols. This makes
non-local symbols appear in their register order, which matches GNU as. The
register order is nice in that you can write tests with interleaved CHECK
prefixes, e.g.
```
// CHECK: something about foo
.globl foo
foo:
// CHECK: something about bar
.globl bar
bar:
```
With the lexicographical order, the user needs to place lexicographical smallest
symbol first or keep CHECK prefixes in one place.
This allows data sections that don't start with `.data` to be
used/created.
Without this, clang's `__attribute__((section("foo")))` would
generate assembly that would not parse.
Differential Revision: https://reviews.llvm.org/D96233
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.
When calculating the symbol offsets to write as provisitonal values
in object files we are only interested in the offset of the symbol
itself. For aliases this offset already includes the offset of the
base symbol.
The testin question was added back in https://reviews.llvm.org/D87407
but I believe the expectations here were incorrect. sym_a lives
at offset 4 and sym_b lives 4 bytes into that (should be 8).
The addresses of the 3 symbosl in this object file are:
foo : 0
sym_a: 4
sym_b: 8
Differential Revision: https://reviews.llvm.org/D96234
GNU as does not sort local symbols. This has several advantages:
* The .symtab order is roughly the symbol occurrence order.
* The closest preceding STT_SECTION symbol is the definition of a local symbol.
* The closest preceding STT_FILE symbol is the defining file of a local symbol, if there are multiple default-version .file directives. (Not implemented in MC.)
As mentioned in TODO comment, casting double to float causes NaNs to change bits.
To avoid the change, this patch adds support for single-floating-point immediate value on MachineCode.
Patch by Yuta Saito.
Differential Revision: https://reviews.llvm.org/D77384
Without `-dwarf-version`, llvm-mc uses the default `MCContext::DwarfVersion` 4.
Without `-gdwarf-N`, Clang cc1as uses `clang::driver::ToolChain::GetDefaultDwarfVersion`
which is 4 on many toolchains. Note: `clang -c` can synthesize .debug_info without -g.
There is currently a MCParser warning upon `.file 0` and MCParser errors upon
`.loc 0` if the DWARF version is less than 5. This causes friction to the
following usage:
```
clang -S -g -gdwarf-5 a.c
// MC warning due to .file 0, MC error due to .loc 0
clang -c a.s
llvm-mc -filetype=obj a.s
```
My idea is that we can just upgrade `MCContext::DwarfVersion` to 5 upon
`.file 0` to make the above commands work.
The downside is that for an explicit version `clang -c -gdwarf-4 a.s`, it can be
argued that the new behavior drops the probably intended diagnostic. I think the
downside is small because in most cases DWARF version for an assembly action
should either match the original compile action or be omitted.
Ongoing discussion taking a similar action for GNU as: https://sourceware.org/pipermail/binutils/2021-January/114980.html
Differential Revision: https://reviews.llvm.org/D94882
On Linux target triples, GNU as sets EI_OSABI to ELFOSABI_GNU when SHF_GNU_RETAIN is used。
On `*-*-freebsd`, it usually sets EI_OSABI to ELFOSABI_FREEBSD.
GNU ld respects SHF_GNU_RETAIN only for ELFOSABI_FREEBSD/ELFOSABI_GNU.
https://sourceware.org/bugzilla/show_bug.cgi?id=27282
MC doesn't set ELFOSABI_GNU for SHF_GNU_RETAIN/STB_GNU_UNIQUE/STT_GNU_IFUNC.
MC assembled object files do not have special semantics in GNU ld.
Reviewed By: psmith
Differential Revision: https://reviews.llvm.org/D95730
Followup to D92052 as I missed an issue as shown via GCC bug https://gcc.gnu.org/PR97827, namely: (e.g.) ".rodata." implies ELF::SHF_ALLOC.
Crossref:
- D73999 / commit 75af9da755
added for LLVM 11 a check that sh_flags and sh_entsize (and sh_type)
changes are an error, in line with GNU assembler.
- D92052 / commit 1deff4009e
permitted the abbreviated form which many assemblers accept and
GCC generates: while the first .section contains the flags and entsize,
subsequent sections simply contain the name without repeating entsize or
flags.
However, the latter patch missed in the check that some flags are automatically set, e.g. '.rodata." implies ELF::SHF_ALLOC.
Related https://bugs.llvm.org/show_bug.cgi?id=48201
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D94072
This reverts commit d806618636.
Review: https://reviews.llvm.org/D92215
We had issues where older versions of wasm-ld were crashing on object
files containing a table symbol. We decided that the best strategy
going forward is to only generate these symbol if refernece types is
enabled. Without reference types enabled we should never geneate a
table symbol or a TABLE_NUMBER relocation.
This revert is in addition to the one already reverted in
https://reviews.llvm.org/D95005.
The plan is to re-land these in updated form after the llvm 12 branch.
Differential Revision: https://reviews.llvm.org/D95420
This reverts commit 418df4a6ab.
This change broke emscripten tests, I believe because it started
generating 5-byte a wide table index in the call_indirect instruction.
Neither v8 nor wabt seem to be able to handle that. The spec
currently says that this is single 0x0 byte and:
"In future versions of WebAssembly, the zero byte occurring in the
encoding of the call_indirectcall_indirect instruction may be used to
index additional tables."
So we need to revisit this change. For backwards compat I guess
we need to guarantee that __indirect_function_table is always at
address zero. We could also consider making this a single-byte
relocation with and assert if have more than 127 tables (for now).
Differential Revision: https://reviews.llvm.org/D95005
Element sections will also need flags, so we shouldn't squat the
WASM_SEGMENT namespace.
Depends on D90948.
Differential Revision: https://reviews.llvm.org/D92315
This patch changes to make call_indirect explicitly refer to the
corresponding function table, residualizing TABLE_NUMBER relocs against
it.
With this change, wasm-ld now sees all references to tables, and can
link multiple tables.
Differential Revision: https://reviews.llvm.org/D90948
Now that the linker handles table symbols, we can allow the frontend to
produce them.
Depends on D91870.
Differential Revision: https://reviews.llvm.org/D92215
Now that the linker handles table symbols, we can allow the frontend to
produce them.
Depends on D91870.
Differential Revision: https://reviews.llvm.org/D92215
Be consistent about asserting before setting WasmIndices. Adding
these assertions revealed that we were duplicating a lot of work
and setting these indexed twice when running in DWO mode.
Differential Revision: https://reviews.llvm.org/D93650
For wasm-ld table linking work to proceed, object files should indicate
if they use an indirect function table. In the future this will be done
by the usual symbols and relocations mechanism, but until that support
lands in the linker, the presence of an `__indirect_function_table` in
the object file's import section shows that the object file needs an
indirect function table.
Prior to https://reviews.llvm.org/D91637, this condition was met by all
object files residualizing an `__indirect_function_table` import.
Since https://reviews.llvm.org/D91637, the intention has been that only
those object files needing an indirect function table would have the
`__indirect_function_table` import. However, we missed the case of
object files which use the table via `call_indirect` but which
themselves do not declare any indirect functions.
This changeset makes it so that when we lower a call to `call_indirect`,
that we ensure that a `__indirect_function_table` symbol is present and
that it will be propagated to the linker.
A followup patch will revise this mechanism to make an explicit link
between `call_indirect` and its associated indirect function table; see
https://reviews.llvm.org/D90948.
Differential Revision: https://reviews.llvm.org/D92840
CanBeUnnamed is rarely false. Splitting to a createNamedTempSymbol makes the
intention clearer and matches the direction of reverted r240130 (to drop the
unneeded parameters).
No behavior change.
Errors from MCAssembler, MCObjectStreamer and *ObjectWriter typically cause a crash:
```
% cat c.c
int bar;
extern int foo __attribute__((alias("bar")));
% clang -c -fcommon c.c
fatal error: error in backend: Common symbol 'bar' cannot be used in assignment expr
PLEASE submit a bug report to ...
Stack dump:
...
```
`LLVMTargetMachine::addPassesToEmitFile` constructs `MachineModuleInfoWrapperPass`
which creates a MCContext without SourceMgr. `MCContext::reportError` calls
`report_fatal_error` which gets captured by Clang `LLVMErrorHandler` and gets translated
to the output above.
Since `MCContext::reportError` errors indicate user errors, such a crashing style error
is inappropriate. So this patch changes `report_fatal_error` to `SourceMgr().PrintMessage`.
```
% clang -c -fcommon c.c
<unknown>:0: error: Common symbol 'bar' cannot be used in assignment expr
```
Ideally we should at least recover the original filename (the line information
is generally lost). That requires general improvement to MC diagnostics,
because currently in many cases SMLoc information is lost.
Currently the integrated assembler only allows commas as the separator
between string arguments in .ascii. This patch adds support to using
space as separators and make IAS consistent with GNU assembler.
Link: https://github.com/ClangBuiltLinux/linux/issues/1196
Reviewed By: nickdesaulniers, jrtc27
Differential Revision: https://reviews.llvm.org/D91460
This relands D64327 with a more specific workaround for R_386_GOTOFF
(gold<2.34 bug https://sourceware.org/bugzilla/show_bug.cgi?id=16794)
.debug_info has quite a few .debug_str relocations (R_386_32/R_ARM_ABS32).
The original workaround was too general and introduced too many .L symbols
used just as relocation targets.
From the original review:
... it reduced the size of a big ARM-32 debug image by 33%. It contained ~68M
of relocations symbols out of total ~71M symbols (96% of symbols table was
generated for relocations with symbol).
This is consistent with the resolution to power-of-2 alignments.
Otherwise, emitCodeAlignment and emitValueToAlignment cannot handle alignments
larger than 2**32 and will trigger assertion failure (PR35218).
Note: GNU as as of 2.35 will use 1 for such a large byte `.align`
D73999 / commit 75af9da755
added for LLVM 11 a check that sh_flags and sh_entsize (and sh_type)
changes are an error, in line with GNU assembler.
However, GNU assembler accepts and GCC generates an abbreviated form:
while the first .section contains the flags and entsize, subsequent
sections simply contain the name without repeating entsize or flags.
Do likewise for better compatibility.
See https://bugs.llvm.org/show_bug.cgi?id=48201
Reviewed By: jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D92052
This change implements pseudo probe encoding and emission for CSSPGO. Please see RFC here for more context: https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s
Pseudo probes are in the form of intrinsic calls on IR/MIR but they do not turn into any machine instructions. Instead they are emitted into the binary as a piece of data in standalone sections. The probe-specific sections are not needed to be loaded into memory at execution time, thus they do not incur a runtime overhead.
**ELF object emission**
The binary data to emit are organized as two ELF sections, i.e, the `.pseudo_probe_desc` section and the `.pseudo_probe` section. The `.pseudo_probe_desc` section stores a function descriptor for each function and the `.pseudo_probe` section stores the actual probes, each fo which corresponds to an IR basic block or an IR function callsite. A function descriptor is stored as a module-level metadata during the compilation and is serialized into the object file during object emission.
Both the probe descriptors and pseudo probes can be emitted into a separate ELF section per function to leverage the linker for deduplication. A `.pseudo_probe` section shares the same COMDAT group with the function code so that when the function is dead, the probes are dead and disposed too. On the contrary, a `.pseudo_probe_desc` section has its own COMDAT group. This is because even if a function is dead, its probes may be inlined into other functions and its descriptor is still needed by the profile generation tool.
The format of `.pseudo_probe_desc` section looks like:
```
.section .pseudo_probe_desc,"",@progbits
.quad 6309742469962978389 // Func GUID
.quad 4294967295 // Func Hash
.byte 9 // Length of func name
.ascii "_Z5funcAi" // Func name
.quad 7102633082150537521
.quad 138828622701
.byte 12
.ascii "_Z8funcLeafi"
.quad 446061515086924981
.quad 4294967295
.byte 9
.ascii "_Z5funcBi"
.quad -2016976694713209516
.quad 72617220756
.byte 7
.ascii "_Z3fibi"
```
For each `.pseudoprobe` section, the encoded binary data consists of a single function record corresponding to an outlined function (i.e, a function with a code entry in the `.text` section). A function record has the following format :
```
FUNCTION BODY (one for each outlined function present in the text section)
GUID (uint64)
GUID of the function
NPROBES (ULEB128)
Number of probes originating from this function.
NUM_INLINED_FUNCTIONS (ULEB128)
Number of callees inlined into this function, aka number of
first-level inlinees
PROBE RECORDS
A list of NPROBES entries. Each entry contains:
INDEX (ULEB128)
TYPE (uint4)
0 - block probe, 1 - indirect call, 2 - direct call
ATTRIBUTE (uint3)
reserved
ADDRESS_TYPE (uint1)
0 - code address, 1 - address delta
CODE_ADDRESS (uint64 or ULEB128)
code address or address delta, depending on ADDRESS_TYPE
INLINED FUNCTION RECORDS
A list of NUM_INLINED_FUNCTIONS entries describing each of the inlined
callees. Each record contains:
INLINE SITE
GUID of the inlinee (uint64)
ID of the callsite probe (ULEB128)
FUNCTION BODY
A FUNCTION BODY entry describing the inlined function.
```
To support building a context-sensitive profile, probes from inlinees are grouped by their inline contexts. An inline context is logically a call path through which a callee function lands in a caller function. The probe emitter builds an inline tree based on the debug metadata for each outlined function in the form of a trie tree. A tree root is the outlined function. Each tree edge stands for a callsite where inlining happens. Pseudo probes originating from an inlinee function are stored in a tree node and the tree path starting from the root all the way down to the tree node is the inline context of the probes. The emission happens on the whole tree top-down recursively. Probes of a tree node will be emitted altogether with their direct parent edge. Since a pseudo probe corresponds to a real code address, for size savings, the address is encoded as a delta from the previous probe except for the first probe. Variant-sized integer encoding, aka LEB128, is used for address delta and probe index.
**Assembling**
Pseudo probes can be printed as assembly directives alternatively. This allows for good assembly code readability and also provides a view of how optimizations and pseudo probes affect each other, especially helpful for diff time assembly analysis.
A pseudo probe directive has the following operands in order: function GUID, probe index, probe type, probe attributes and inline context. The directive is generated by the compiler and can be parsed by the assembler to form an encoded `.pseudoprobe` section in the object file.
A example assembly looks like:
```
foo2: # @foo2
# %bb.0: # %bb0
pushq %rax
testl %edi, %edi
.pseudoprobe 837061429793323041 1 0 0
je .LBB1_1
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 6 2 0
callq foo
.pseudoprobe 837061429793323041 3 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
.LBB1_1: # %bb1
.pseudoprobe 837061429793323041 5 1 0
callq *%rsi
.pseudoprobe 837061429793323041 2 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
# -- End function
.section .pseudo_probe_desc,"",@progbits
.quad 6699318081062747564
.quad 72617220756
.byte 3
.ascii "foo"
.quad 837061429793323041
.quad 281547593931412
.byte 4
.ascii "foo2"
```
With inlining turned on, the assembly may look different around %bb2 with an inlined probe:
```
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 3 0
.pseudoprobe 6699318081062747564 1 0 @ 837061429793323041:6
.pseudoprobe 837061429793323041 4 0
popq %rax
retq
```
**Disassembling**
We have a disassembling tool (llvm-profgen) that can display disassembly alongside with pseudo probes. So far it only supports ELF executable file.
An example disassembly looks like:
```
00000000002011a0 <foo2>:
2011a0: 50 push rax
2011a1: 85 ff test edi,edi
[Probe]: FUNC: foo2 Index: 1 Type: Block
2011a3: 74 02 je 2011a7 <foo2+0x7>
[Probe]: FUNC: foo2 Index: 3 Type: Block
[Probe]: FUNC: foo2 Index: 4 Type: Block
[Probe]: FUNC: foo Index: 1 Type: Block Inlined: @ foo2:6
2011a5: 58 pop rax
2011a6: c3 ret
[Probe]: FUNC: foo2 Index: 2 Type: Block
2011a7: bf 01 00 00 00 mov edi,0x1
[Probe]: FUNC: foo2 Index: 5 Type: IndirectCall
2011ac: ff d6 call rsi
[Probe]: FUNC: foo2 Index: 4 Type: Block
2011ae: 58 pop rax
2011af: c3 ret
```
Reviewed By: wmi
Differential Revision: https://reviews.llvm.org/D91878
This CL changes the asm syntax for section flags, making them more like ELF
(previously "passive" was the only option). Now we also allow "G" to designate
COMDAT group sections. In these sections we set the appropriate comdat flag on
function symbols, and also avoid auto-creating a new section for them.
This also adds asm-based tests for the changes D92691 to go along with
the direct-to-object tests.
Differential Revision: https://reviews.llvm.org/D92952
This is a reland of rG4564553b8d8a with a fix to the lit pipeline in
llvm/test/MC/WebAssembly/comdat.ll
This CL changes the asm syntax for section flags, making them more like ELF
(previously "passive" was the only option). Now we also allow "G" to designate
COMDAT group sections. In these sections we set the appropriate comdat flag on
function symbols, and also avoid auto-creating a new section for them.
This also adds asm-based tests for the changes D92691 to go along with
the direct-to-object tests.
Differential Revision: https://reviews.llvm.org/D92952
This change implements pseudo probe encoding and emission for CSSPGO. Please see RFC here for more context: https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s
Pseudo probes are in the form of intrinsic calls on IR/MIR but they do not turn into any machine instructions. Instead they are emitted into the binary as a piece of data in standalone sections. The probe-specific sections are not needed to be loaded into memory at execution time, thus they do not incur a runtime overhead.
**ELF object emission**
The binary data to emit are organized as two ELF sections, i.e, the `.pseudo_probe_desc` section and the `.pseudo_probe` section. The `.pseudo_probe_desc` section stores a function descriptor for each function and the `.pseudo_probe` section stores the actual probes, each fo which corresponds to an IR basic block or an IR function callsite. A function descriptor is stored as a module-level metadata during the compilation and is serialized into the object file during object emission.
Both the probe descriptors and pseudo probes can be emitted into a separate ELF section per function to leverage the linker for deduplication. A `.pseudo_probe` section shares the same COMDAT group with the function code so that when the function is dead, the probes are dead and disposed too. On the contrary, a `.pseudo_probe_desc` section has its own COMDAT group. This is because even if a function is dead, its probes may be inlined into other functions and its descriptor is still needed by the profile generation tool.
The format of `.pseudo_probe_desc` section looks like:
```
.section .pseudo_probe_desc,"",@progbits
.quad 6309742469962978389 // Func GUID
.quad 4294967295 // Func Hash
.byte 9 // Length of func name
.ascii "_Z5funcAi" // Func name
.quad 7102633082150537521
.quad 138828622701
.byte 12
.ascii "_Z8funcLeafi"
.quad 446061515086924981
.quad 4294967295
.byte 9
.ascii "_Z5funcBi"
.quad -2016976694713209516
.quad 72617220756
.byte 7
.ascii "_Z3fibi"
```
For each `.pseudoprobe` section, the encoded binary data consists of a single function record corresponding to an outlined function (i.e, a function with a code entry in the `.text` section). A function record has the following format :
```
FUNCTION BODY (one for each outlined function present in the text section)
GUID (uint64)
GUID of the function
NPROBES (ULEB128)
Number of probes originating from this function.
NUM_INLINED_FUNCTIONS (ULEB128)
Number of callees inlined into this function, aka number of
first-level inlinees
PROBE RECORDS
A list of NPROBES entries. Each entry contains:
INDEX (ULEB128)
TYPE (uint4)
0 - block probe, 1 - indirect call, 2 - direct call
ATTRIBUTE (uint3)
reserved
ADDRESS_TYPE (uint1)
0 - code address, 1 - address delta
CODE_ADDRESS (uint64 or ULEB128)
code address or address delta, depending on ADDRESS_TYPE
INLINED FUNCTION RECORDS
A list of NUM_INLINED_FUNCTIONS entries describing each of the inlined
callees. Each record contains:
INLINE SITE
GUID of the inlinee (uint64)
ID of the callsite probe (ULEB128)
FUNCTION BODY
A FUNCTION BODY entry describing the inlined function.
```
To support building a context-sensitive profile, probes from inlinees are grouped by their inline contexts. An inline context is logically a call path through which a callee function lands in a caller function. The probe emitter builds an inline tree based on the debug metadata for each outlined function in the form of a trie tree. A tree root is the outlined function. Each tree edge stands for a callsite where inlining happens. Pseudo probes originating from an inlinee function are stored in a tree node and the tree path starting from the root all the way down to the tree node is the inline context of the probes. The emission happens on the whole tree top-down recursively. Probes of a tree node will be emitted altogether with their direct parent edge. Since a pseudo probe corresponds to a real code address, for size savings, the address is encoded as a delta from the previous probe except for the first probe. Variant-sized integer encoding, aka LEB128, is used for address delta and probe index.
**Assembling**
Pseudo probes can be printed as assembly directives alternatively. This allows for good assembly code readability and also provides a view of how optimizations and pseudo probes affect each other, especially helpful for diff time assembly analysis.
A pseudo probe directive has the following operands in order: function GUID, probe index, probe type, probe attributes and inline context. The directive is generated by the compiler and can be parsed by the assembler to form an encoded `.pseudoprobe` section in the object file.
A example assembly looks like:
```
foo2: # @foo2
# %bb.0: # %bb0
pushq %rax
testl %edi, %edi
.pseudoprobe 837061429793323041 1 0 0
je .LBB1_1
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 6 2 0
callq foo
.pseudoprobe 837061429793323041 3 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
.LBB1_1: # %bb1
.pseudoprobe 837061429793323041 5 1 0
callq *%rsi
.pseudoprobe 837061429793323041 2 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
# -- End function
.section .pseudo_probe_desc,"",@progbits
.quad 6699318081062747564
.quad 72617220756
.byte 3
.ascii "foo"
.quad 837061429793323041
.quad 281547593931412
.byte 4
.ascii "foo2"
```
With inlining turned on, the assembly may look different around %bb2 with an inlined probe:
```
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 3 0
.pseudoprobe 6699318081062747564 1 0 @ 837061429793323041:6
.pseudoprobe 837061429793323041 4 0
popq %rax
retq
```
**Disassembling**
We have a disassembling tool (llvm-profgen) that can display disassembly alongside with pseudo probes. So far it only supports ELF executable file.
An example disassembly looks like:
```
00000000002011a0 <foo2>:
2011a0: 50 push rax
2011a1: 85 ff test edi,edi
[Probe]: FUNC: foo2 Index: 1 Type: Block
2011a3: 74 02 je 2011a7 <foo2+0x7>
[Probe]: FUNC: foo2 Index: 3 Type: Block
[Probe]: FUNC: foo2 Index: 4 Type: Block
[Probe]: FUNC: foo Index: 1 Type: Block Inlined: @ foo2:6
2011a5: 58 pop rax
2011a6: c3 ret
[Probe]: FUNC: foo2 Index: 2 Type: Block
2011a7: bf 01 00 00 00 mov edi,0x1
[Probe]: FUNC: foo2 Index: 5 Type: IndirectCall
2011ac: ff d6 call rsi
[Probe]: FUNC: foo2 Index: 4 Type: Block
2011ae: 58 pop rax
2011af: c3 ret
```
Reviewed By: wmi
Differential Revision: https://reviews.llvm.org/D91878
There is an explicit option for the lexer to support this, but we crash
when `-preserve-comments` is enabled because it checks for
`getTok().getString().empty()` to detect the case. This doesn't
work currently because the lexer reports this case as a string of length
1, containing a null byte.
Change the lexer to instead report this case via an empty string, as the
null terminator isn't logically a part of the textual input, and the
check for `.empty()` seems natural and obvious in the calling code.
Reviewed By: niravd
Differential Revision: https://reviews.llvm.org/D92681
Allow sections to be placed into COMDAT groups, in addtion to functions and data
segments.
Also make section symbols unnamed, which allows sections with identical names
(section names are independent of their section symbols, but previously we
gave the symbols the same name as their sections, which results in collisions
when sections are identically-named).
Differential Revision: https://reviews.llvm.org/D92691
Notes:
* llvm::createAsmStreamer: it has been moved to TargetRegistry.h
* (anon ns)::WasmObjectWriter::updateCustomSectionRelocations: remnant of D46335
* COFFAsmParser::ParseSEHRegisterNumber: remnant of D66625
* llvm::CodeViewContext::isValidCVFileNumber: accidentally added by r279847
Previously these directives were always interpreted as having an extra
blank line after them.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D92612
Summary:
Not all system assembler supports `.uleb128 label2 - label1` form.
When the target do not support this form, we have to take
alternative manual calculation to get the offsets from them.
Reviewed By: hubert.reinterpretcast
Diffierential Revision: https://reviews.llvm.org/D92058
Summary:
AIX uses the existing EH infrastructure in clang and llvm.
The major differences would be
1. AIX do not have CFI instructions.
2. AIX uses a new personality routine, named __xlcxx_personality_v1.
It doesn't use the GCC personality rountine, because the
interoperability is not there yet on AIX.
3. AIX do not use eh_frame sections. Instead, it would use a eh_info
section (compat unwind section) to store the information about
personality routine and LSDA data address.
Reviewed By: daltenty, hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D91455
Currently, `llvm_bb_addr_map` sections are generated per section names because we use
the `LinkedToSymbol` argument of getELFSection. This will cause the address map tables of functions
grouped into the same section when `-function-sections=true -unique-section-names=false` which is not
the intended behaviour. This patch lets the unique id of every `.text` section propagate to the associated
`.llvm_bb_addr_map` section.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D92113
If prefaced with a %, expand text macros and macro functions in any statement.
Also, prevent expanding text macros in the message of an ECHO directive unless expanded explicitly by the statement expansion operator.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89740
Similar to D92113. Currently `clang -fstack-size-section -fno-unique-section-names`
sets the linked-to symbol to the first `.text`, which is:
* incorrect for COMDAT sections
* inferior for non-COMDAT sections in -ffunction-sections mode (poor --gc-sections: .stack_sizes cannot be separately discarded)
Note, if the section symbol can be referenced in more places (if the
function begin symbol does not apply), we probably should consider
defining a different BeginSymbol for sections with ",unique" linkage.
Reviewed By: grimar, jhenderson
Differential Revision: https://reviews.llvm.org/D92151
In text-item contexts, %expr expands to a string containing the results of evaluating `expr`.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89736
The indirect function table, synthesized by the linker, is needed if and
only if there are TABLE_INDEX relocs.
Differential Revision: https://reviews.llvm.org/D91637
This commit factors out a WasmTableType definition from WasmTable, as is
the case for WasmGlobal and other data types. Also add support for
extracting the SymbolName for a table from the linking section's symbol
table.
Differential Revision: https://reviews.llvm.org/D91849
This reapplies 36c64af9d7 in updated
form.
Emit the xdata for each function at .seh_endproc. This keeps the
exact same output header order for most code generated by the LLVM
CodeGen layer. (Sections still change order for code built from
assembly where functions lack an explicit .seh_handlerdata
directive, and functions with chained unwind info.)
The practical effect should be that assembly output lacks
superfluous ".seh_handlerdata; .text" pairs at the end of functions
that don't handle exceptions, which allows such functions to use
the AArch64 packed unwind format again.
Differential Revision: https://reviews.llvm.org/D87448
Accept macro function definitions, and apply them when invoked in operand position.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89734
2c196bbc6b asserted that
`SmallVector::push_back` doesn't invalidate the parameter when it needs
to grow. Do the same for `resize`, `append`, `assign`, `insert`, and
`emplace_back`.
Differential Revision: https://reviews.llvm.org/D91744
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=4acf8c78e659833be8be047ba2f8561386a11d4b
(1994) introduced this behavior:
if a fixup symbol is equated to an expression with an undefined symbol, convert
the fixup to be against the target symbol. glibc relies on this behavior to perform
assembly level indirection
```
asm("memcpy = __GI_memcpy"); // from sysdeps/generic/symbol-hacks.h
...
// call memcpy@PLT
// The relocation references __GI_memcpy in GNU as, but memcpy in MC (without the patch)
memcpy (...);
```
(1) It complements `extern __typeof(memcpy) memcpy asm("__GI_memcpy");` The frontend asm label does not redirect synthesized memcpy in the middle-end. (See D88712 for details)
(2) `asm("memcpy = __GI_memcpy");` is in every translation unit, but the memcpy declaration may not be visible in the translation unit where memcpy is synthesized.
MC already redirects `memcpy = __GI_memcpy; call memcpy` but not `memcpy = __GI_memcpy; call memcpy@plt`.
This patch fixes the latter by allowing MCExpr::evaluateAsRelocatableImpl to
evaluate a non-VK_None MCSymbolRefExpr, which is only done after the layout is available.
GNU as allows `memcpy = __GI_memcpy+1; call memcpy@PLT` which seems nonsensical, so we don't allow it.
`MC/PowerPC/pr38945.s` `NUMBER = 0x6ffffff9; cmpwi 8,NUMBER@l` requires the
`symbol@l` form in AsmMatcher, so evaluation needs to be deferred. This is the
place whether future simplification may be possible.
Note, if we suppress the VM_None evaluation when MCAsmLayout is nullptr, we may
lose the `invalid reassignment of non-absolute variable` diagnostic
(`ARM/thumb_set-diagnostics.s` and `MC/AsmParser/variables-invalid.s`).
We know that this diagnostic is troublesome in some cases
(https://github.com/ClangBuiltLinux/linux/issues/1008), so we can consider
making simplification in the future.
Reviewed By: jyknight
Differential Revision: https://reviews.llvm.org/D88625
This patch adds support for creating Guard Address-Taken IAT Entry Tables (.giats$y sections) in object files, matching the behavior of MSVC. These contain lists of address-taken imported functions, which are used by the linker to create the final GIATS table.
Additionally, if any DLLs are delay-loaded, the linker must look through the .giats tables and add the respective load thunks of address-taken imports to the GFIDS table, as these are also valid call targets.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D87544
This patch uses the new `getMnemonic` helper from D90039
to display mnemonics instead of the internal opcodes.
The main motivation behind using the mnemonics is that they
are more user-friendly and more directly related to the assembly
the users will be presented.
Reviewed By: paquette
Differential Revision: https://reviews.llvm.org/D90040
These relocations represent offsets from the __tls_base symbol.
Previously we were just using normal MEMORY_ADDR relocations and relying
on the linker to select a segment-offset rather and absolute value in
Symbol::getVirtualAddress(). Using an explicit relocation type allows
allow us to clearly distinguish absolute from relative relocations based
on the relocation information alone.
One place this is useful is being able to reject absolute relocation in
the PIC case, but still accept TLS relocations.
Differential Revision: https://reviews.llvm.org/D91276
No longer rely on an external tool to build the llvm component layout.
Instead, leverage the existing `add_llvm_componentlibrary` cmake function and
introduce `add_llvm_component_group` to accurately describe component behavior.
These function store extra properties in the created targets. These properties
are processed once all components are defined to resolve library dependencies
and produce the header expected by llvm-config.
Differential Revision: https://reviews.llvm.org/D90848
I was trying to add .cfi_ annotations to assembly code in the FreeBSD
kernel and changed a macro that then resulted in incorrectly nested
directives. However, clang's diagnostics said the error was happening at
<unknown>:0. This addresses one of the TODOs added in D51695.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D89787
This broke both Firefox and Chromium (PR47905) due to what seems like dllimport
function not being handled correctly.
> This patch adds support for creating Guard Address-Taken IAT Entry Tables (.giats$y sections) in object files, matching the behavior of MSVC. These contain lists of address-taken imported functions, which are used by the linker to create the final GIATS table.
> Additionally, if any DLLs are delay-loaded, the linker must look through the .giats tables and add the respective load thunks of address-taken imports to the GFIDS table, as these are also valid call targets.
>
> Reviewed By: rnk
>
> Differential Revision: https://reviews.llvm.org/D87544
This reverts commit cfd8481da1.
Support MASM's REPEAT, FOR, FORC, and WHILE macro-like directives.
Also adds support for macro argument substitution inside quoted strings, and additional testing for macro directives.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89732
MASM interprets strings in expression contexts as integers expressed in big-endian base-256, treating each character as its ASCII representation.
This completely eliminates the need to special-case single-character strings.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D90788
Makes sure that the unwind info uses 64bits pcrel relocation if a large code model is specified and handle the corresponding relocation in the ExecutionEngine. This can happen with certain kernel configuration (the same as the one in https://reviews.llvm.org/D27609, found at least on the ArchLinux stock kernel and the one used on https://www.packet.net/) using the builtin JIT memory manager.
Co-authored-by: Yichao Yu <yyc1992@gmail.com>
Differential Revision: https://reviews.llvm.org/D27629
Allow single-quoted strings and double-quoted character values, as well as doubled-quote escaping.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89731
Allows the MACRO directive to define macro procedures with parameters and macro-local symbols.
Supports required and optional parameters (including default values), and matches ml64.exe for its macro-local symbol handling (up to 65536 macro-local symbols in any translation unit).
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89729
A SMLoc allows MCStreamer to report location-aware diagnostics, which
were previously done by adding SMLoc to various methods (e.g. emit*) in an ad-hoc way.
Since the file:line is most important, the column is less important and
the start token location suffices in many cases, this patch reverts
b7e7131af2
```
// old
symbol-binding-changed.s:6:8: error: local changed binding to STB_GLOBAL
.globl local
^
// new
symbol-binding-changed.s:6:1: error: local changed binding to STB_GLOBAL
.globl local
^
```
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D90511
If MCContext has an error, MCAssembler::layout may stop early
and some MCFragment's may not finalize.
In the Linux kernel, arch/x86/lib/memcpy_64.S could trigger the assert before
"x86_64: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S"
GNU as let .weak override .globl since binutils-gdb
5ca547dc2399a0a5d9f20626d4bf5547c3ccfddd (1996) while MC lets the last
directive win (PR38921).
This caused an issue to Linux's powerpc port which has been fixed by
http://git.kernel.org/linus/968339fad422a58312f67718691b717dac45c399
Binding overriding is error-prone. This patch disallows a changed binding.
(https://sourceware.org/pipermail/binutils/2020-March/000299.html )
Our behavior regarding `.globl x; .weak x` matches GNU as. Such usage is
still suspicious but we issue a warning for now. We may upgrade it to an
error in the future.
Reviewed By: jhenderson, nickdesaulniers
Differential Revision: https://reviews.llvm.org/D90108
Since Wasm comdat sections work similarly to ELF, we can use that mechanism
to eliminate duplicate dwarf type information in the same way.
Differential Revision: https://reviews.llvm.org/D88603
Since Wasm comdat sections work similarly to ELF, we can use that mechanism
to eliminate duplicate dwarf type information in the same way.
Differential Revision: https://reviews.llvm.org/D88603
Implementation of instructions table.get, table.set, table.grow,
table.size, table.fill, table.copy.
Missing instructions are table.init and elem.drop as they deal with
element sections which are not yet implemented.
Added more tests to tables.s
Differential Revision: https://reviews.llvm.org/D89797
LD64 emits string tables which start with a space and a zero byte.
This diff adjusts StringTableBuilder for linked Mach-O binaries to match LD64's behavior.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D89561
This patch adds support for creating Guard Address-Taken IAT Entry Tables (.giats$y sections) in object files, matching the behavior of MSVC. These contain lists of address-taken imported functions, which are used by the linker to create the final GIATS table.
Additionally, if any DLLs are delay-loaded, the linker must look through the .giats tables and add the respective load thunks of address-taken imports to the GFIDS table, as these are also valid call targets.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D87544
Adds more testing in basic-assembly.s and a new test tables.s.
Adds support to yaml reading and writing of tables as well.
Differential Revision: https://reviews.llvm.org/D88815
This patch lets the bb_addr_map (renamed to __llvm_bb_addr_map) section use a special section type (SHT_LLVM_BB_ADDR_MAP) instead of SHT_PROGBITS. This would help parsers, dumpers and other tools to use the sh_type ELF field to identify this section rather than relying on string comparison on the section name.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D88199
This patch adds support for creating Guard Address-Taken IAT Entry Tables (.giats$y sections) in object files, matching the behavior of MSVC. These contain lists of address-taken imported functions, which are used by the linker to create the final GIATS table.
Additionally, if any DLLs are delay-loaded, the linker must look through the .giats tables and add the respective load thunks of address-taken imports to the GFIDS table, as these are also valid call targets.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D87544
This patch improves the assembly output produced for string literals by
using character literals in byte lists. This provides the benefits of
having printable characters appear as such in the assembly output and of
having strings kept as logical units on the same line.
Reviewed By: daltenty
Differential Revision: https://reviews.llvm.org/D80953
MASM allows arbitrary whitespace around the Intel dot operator, especially when used for struct field lookup
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D88450
Support the "alias" directive.
Required support for emitWeakReference in MCWinCOFFStreamer.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D87403
Add support for .radix directive, and radix specifiers [yY] (binary), [oOqQ] (octal), and [tT] (decimal).
Also, when lexing MASM integers, require radix specifier; MASM requires that all literals without a radix specifier be treated as in the default radix. (e.g., 0100 = 100)
Relanding D87400, now with fewer ms-inline-asm tests broken!
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D88337
Avoid introducing unnecessary indirection for weak-external references.
We only need to introduce ".weak.<SYMBOL>.default" when referencing a
symbol that is defined, but not external.
Reviewed By: mstorsjo
Differential Revision: https://reviews.llvm.org/D88305
There are two `WasmSignature` structs, one in
include/llvm/BinaryFormat/Wasm.h and the other in
lib/MC/WasmObjectWriter.cpp. I don't know why they got separated in this
way in the first place, but it seems we can unify them to use the one in
Wasm.h for all cases.
Reviewed By: dschuff, sbc100
Differential Revision: https://reviews.llvm.org/D88428
This patch is the initial support for the Local Dynamic Thread Local Storage
model to produce code sequence and relocation correct to the ABI for the model
when using PC relative memory operations.
Differential Revision: https://reviews.llvm.org/D87721
Add support for .radix directive, and radix specifiers [yY] (binary), [oOqQ] (octal), and [tT] (decimal).
Also, when lexing MASM integers, require radix specifier; MASM requires that all literals without a radix specifier be treated as in the default radix. (e.g., 0100 = 100)
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D87400
In practice, this only gives modest savings (for a 6.5 MB DLL with
230 KB xdata, the xdata sections shrinks by around 2.5 KB); to
gain more, the frame lowering would need to be tweaked to more often
generate frame layouts that match the canonical layouts that can
be written in packed form.
Differential Revision: https://reviews.llvm.org/D87371
For relative symbols, add its offset when computing relocation value.
Also, warn on unsupported absolute symbols.
Differential Revision: https://reviews.llvm.org/D87407
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
MASM structs are end-padded to have size a multiple of the smaller of the requested alignment and the size of their largest field (taken recursively, if they have a field of STRUCT type).
This matches the behavior of ml.exe and ml64.exe. Our original implementation followed the MASM 6.0 documentation, which instead specified that MASM structs were padded to a multiple of their requested alignment.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D87248
Add signed aliases for integral types, as well as the "DF" abbreviation for the FWORD type.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D87246
This patch introduces the new .bb_addr_map section feature which allows us to emit the bits needed for mapping binary profiles to basic blocks into a separate section.
The format of the emitted data is represented as follows. It includes a header for every function:
| Address of the function | -> 8 bytes (pointer size)
| Number of basic blocks in this function (>0) | -> ULEB128
The header is followed by a BB record for every basic block. These records are ordered in the same order as MachineBasicBlocks are placed in the function. Each BB Info is structured as follows:
| Offset of the basic block relative to function begin | -> ULEB128
| Binary size of the basic block | -> ULEB128
| BB metadata | -> ULEB128 [ MBB.isReturn() OR MBB.hasTailCall() << 1 OR MBB.isEHPad() << 2 ]
The new feature will replace the existing "BB labels" functionality with -basic-block-sections=labels.
The .bb_addr_map section scrubs the specially-encoded BB symbols from the binary and makes it friendly to profilers and debuggers.
Furthermore, the new feature reduces the binary size overhead from 70% bloat to only 12%.
For more information and results please refer to the RFC: https://lists.llvm.org/pipermail/llvm-dev/2020-July/143512.html
Reviewed By: MaskRay, snehasish
Differential Revision: https://reviews.llvm.org/D85408
Summary:
In small code model, AIX assembler could not deal with labels that
could not be reached within the [-0x8000, 0x8000) range from TOC base.
So when generating the assembly, we would need to help the assembler
by subtracting an offset from the label to keep the actual value
within [-0x8000, 0x8000).
Reviewed By: hubert.reinterpretcast, Xiangling_L
Differential Revision: https://reviews.llvm.org/D86879
This gives a pretty substantial size reduction; for a 6.5 MB
DLL with 300 KB .xdata, the .xdata shrinks by 66 KB.
Differential Revision: https://reviews.llvm.org/D87369
Convert 2-byte opcodes to equivalent 1-byte ones.
Adjust the existing exhaustive testcase to avoid being altered by
the simplification rules (to keep that test exercising all individual
opcodes).
Fix the assembler parser limits for register pairs; for .seh_save_regp
and .seh_save_regp_x, we can allow up to x29, for a x29+x30 pair
(which gets remapped to the UOP_SaveFPLR(X) opcodes), for .seh_save_fregp
and .seh_save_fregpx, allow up to d14+d15.
Not creating .seh_save_next for float register pairs, as the
actual unwinder implementation in current versions of Windows is buggy
for that case.
This gives a minimal but measurable size reduction. (For a 6.5 MB
DLL with 300 KB .xdata, the .xdata shrinks by 48 bytes. The opcode
sequences are padded to a 4 byte boundary, so very small improvements
might not end up mattering directly.)
Differential Revision: https://reviews.llvm.org/D87367
MASM allows variables defined by equate statements to be used in expressions.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D86946
MASM aligns fields to the _minimum_ of the STRUCT alignment value and the size of the next field.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D86945
Previous implementations for the TLS models General Dynamic and Initial Exec
were missing the ELF::STT_TLS type on symbols that required the type. This patch
adds the type.
Reviewed By: sfertile, MaskRay
Differential Revision: https://reviews.llvm.org/D86777
Add support in llvm-readobj for displaying them and support in the
asm parsser, AArch64TargetStreamer and MCWin64EH for emitting them.
The directives for the remaining basic opcodes have names that
match the opcode in the documentation.
The directives for custom stack cases, that are named
MSFT_OP_TRAP_FRAME, MSFT_OP_MACHINE_FRAME, MSFT_OP_CONTEXT
and MSFT_OP_CLEAR_UNWOUND_TO_CALL, are given matching assembler
directive names that fit into the rest of the opcode naming;
.seh_trap_frame, .seh_context, .seh_clear_unwound_to_call
The opcode MSFT_OP_MACHINE_FRAME is mapped to the existing
opecode enum UOP_PushMachFrame that is used on x86_64, and also
uses the corresponding existing x86_64 directive name
.seh_pushframe.
Differential Revision: https://reviews.llvm.org/D86889
Add support for line continuations (the "backslash operator") in MASM by modifying the Parser's Lex method.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D83347
This ensures that you get the same output regardless if generating
code directly to an object file or if generating assembly and
assembling that.
Add implementations of the EmitARM64WinCFI*() methods in
AArch64TargetAsmStreamer, and fill in one blank in MCAsmStreamer.
Add corresponding directive handlers in AArch64AsmParser and
COFFAsmParser.
Some SEH directive names have been picked to match the prior art
for SEH assembly directives for x86_64, e.g. the spelling of
".seh_startepilogue" matching the preexisting ".seh_endprologue".
For the directives for saving registers, the exact spelling
from the arm64 documentation is picked, e.g. ".seh_save_reg" (to follow
that naming for all the other ones, e.g. ".seh_save_fregp_x"), while
the corresponding one for x86_64 is plain ".seh_savereg" without the
second underscore.
Directives in the epilogues have the same names as in prologues,
e.g. .seh_savereg, even though the registers are restored, not
saved, at that point.
Differential Revision: https://reviews.llvm.org/D86529
This can happen e.g. for code that declare .seh_proc/.seh_endproc
in assembly, or for code that use .seh_handlerdata (which triggers
the unwind info to be emitted before the end of the function).
The TextSection field must be made non-const to be able to use it
with Streamer.SwitchSection().
Differential Revision: https://reviews.llvm.org/D86528
If there's no unwinding opcodes, omit writing the xdata/pdata records.
Previously, this generated truncated xdata records, and llvm-readobj
would error out when trying to print them.
If writing of an xdata record is forced via the .seh_handlerdata
directive, skip it if there's no info to make a sensible unwind
info structure out of, and clearly error out if such info appeared
later in the process.
Differential Revision: https://reviews.llvm.org/D86527
Summary:
Support TOCU and TOCL relocation type for object file generation.
Reviewed by: DiggerLin
Differential Revision: https://reviews.llvm.org/D84549
This patch is the initial support for the Intial Exec Thread Local
Local Storage model to produce code sequence and relocations correct
to the ABI for the model when using PC relative memory operations.
Reviewed By: stefanp
Differential Revision: https://reviews.llvm.org/D81947
This patch is the initial support for the General Dynamic Thread Local
Local Storage model to produce code sequence and relocations correct
to the ABI for the model when using PC relative memory operations.
Patch by: NeHuang
Reviewed By: stefanp
Differential Revision: https://reviews.llvm.org/D82315
Summary:
This is a follow up for D82481. For .lcomm directive, although it's
not necessary to have .rename emitted, it's still desirable to do
it so that we do not see internal 'Rename..' gets print out in
symbol table. And we could have consistent naming between TC entry
and .lcomm. And also have consistent naming between IR and final
object file.
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D86075
This patch implements initial backend support for a -mtune CPU controlled by a "tune-cpu" function attribute. If the attribute is not present X86 will use the resolved CPU from target-cpu attribute or command line.
This patch adds MC layer support a tune CPU. Each CPU now has two sets of features stored in their GenSubtargetInfo.inc tables . These features lists are passed separately to the Processor and ProcessorModel classes in tablegen. The tune list defaults to an empty list to avoid changes to non-X86. This annoyingly increases the size of static tables on all target as we now store 24 more bytes per CPU. I haven't quantified the overall impact, but I can if we're concerned.
One new test is added to X86 to show a few tuning features with mismatched tune-cpu and target-cpu/target-feature attributes to demonstrate independent control. Another new test is added to demonstrate that the scheduler model follows the tune CPU.
I have not added a -mtune to llc/opt or MC layer command line yet. With no attributes we'll just use the -mcpu for both. MC layer tools will always follow the normal CPU for tuning.
Differential Revision: https://reviews.llvm.org/D85165
Define the platform ID = 10, and simple mappings between platform ID & name.
Reviewed By: MaskRay, cishida
Differential Revision: https://reviews.llvm.org/D85594
SUMMARY:
1. in the patch , remove setting storageclass in function .getXCOFFSection and construct function of class MCSectionXCOFF
there are
XCOFF::StorageMappingClass MappingClass;
XCOFF::SymbolType Type;
XCOFF::StorageClass StorageClass;
in the MCSectionXCOFF class,
these attribute only used in the XCOFFObjectWriter, (asm path do not need the StorageClass)
we need get the value of StorageClass, Type,MappingClass before we invoke the getXCOFFSection every time.
actually , we can get the StorageClass of the MCSectionXCOFF from it's delegated symbol.
2. we also change the oprand of branch instruction from symbol name to qualify symbol name.
for example change
bl .foo
extern .foo
to
bl .foo[PR]
extern .foo[PR]
3. and if there is reference indirect call a function bar.
we also add
extern .bar[PR]
Reviewers: Jason liu, Xiangling Liao
Differential Revision: https://reviews.llvm.org/D84765
Adds the binary format goff and the operating system zos to the triple
class. goff is selected as default binary format if zos is choosen as
operating system. No further functionality is added.
Reviewers: efriedma, tahonermann, hubert.reinterpertcast, MaskRay
Reviewed By: efriedma, tahonermann, hubert.reinterpertcast
Differential Revision: https://reviews.llvm.org/D82081
Summary:
Use TE SMC instead of TC SMC in large code model mode,
so that large code model TOC entries could get placed after all
the small code model TOC entries, which reduces the chance of TOC overflow.
Reviewed By: Xiangling_L
Differential Revision: https://reviews.llvm.org/D85455
Summary:
AIX assembler does not generate correct relocation when .rename
appear between tc entry label and .tc directive.
So only emit .rename after .tc/.comm or other linkage is emitted.
Reviewed By: daltenty, hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D85317
This reverts commit b497665d98.
Spent some time trying to reproduce this locally, reverting in a
desparate attempt to fix the sanitizer buildbot:
- http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/28828
I don't know exactly why or how this patch breaks the bots, but it seems
pretty concrete that it's the culprit.
Adds the function createMCInst() to MCContext that creates a MCInst using
a typed bump alloctor.
MCInst contains a SmallVector<MCOperand, 8>. The SmallVector is POD only
for <= 8 operands. The default untyped bump pointer allocator of MCContext
does not delete the MCInst, so if the SmallVector grows, it's a leak.
This fixes https://bugs.llvm.org/show_bug.cgi?id=46900.
Part of https://bugs.llvm.org/show_bug.cgi?id=41734
LTO can drop externally available definitions. Such AssociatedSymbol is
not associated with a symbol. ELFWriter::writeSection() will assert.
Allow a SHF_LINK_ORDER section to have sh_link=0.
We need to give sh_link a syntax, a literal zero in the linked-to symbol
position, e.g. `.section name,"ao",@progbits,0`
Reviewed By: pcc
Differential Revision: https://reviews.llvm.org/D72899
This drops a GNU gold workaround and reverts the revert commit rL366708.
Before binutils 2.34, gold -O2 and above did not correctly handle R_386_GOTOFF to
SHF_MERGE|SHF_STRINGS sections: https://sourceware.org/bugzilla/show_bug.cgi?id=16794
From the original review:
... it reduced the size of a big ARM-32 debug image by 33%. It contained ~68M
of relocations symbols out of total ~71M symbols (96% of symbols table was
generated for relocations with symbol).
-Wl,-O2 (and -Wl,-O3) is so rare that we should just lower the
optimization level for LLVM_LINKER_IS_GOLD rather than pessimizing all users.
For comdats (e.g. caused by -ffunction-sections), Section is already
set here; make sure it's null, for the weak external symbol to be undefined.
This fixes PR46779.
Differential Revision: https://reviews.llvm.org/D84507
A linker optimization is available on PowerPC for GOT indirect PCRelative loads.
The idea is that we can mark a usual GOT indirect load:
pld 3, vec@got@pcrel(0), 1
lwa 3, 4(3)
With a relocation to say that if we don't need to go through the GOT we can let
the linker further optimize this and replace a load with a nop.
pld 3, vec@got@pcrel(0), 1
.Lpcrel1:
.reloc .Lpcrel1-8,R_PPC64_PCREL_OPT,.-(.Lpcrel1-8)
lwa 3, 4(3)
This patch adds the logic that allows the compiler to add the R_PPC64_PCREL_OPT.
Reviewers: nemanjai, lei, hfinkel, sfertile, efriedma, tstellar, grosbach
Reviewed By: nemanjai
Differential Revision: https://reviews.llvm.org/D79864
When the compiler generates a GOT indirect load it must generate two loads. One
that loads the address of the element from the GOT and a second to load the
actual element based on the address just loaded from the GOT. However, the
linker can optimize these two loads into one load if it knows that it is safe
to do so. The compiler can tell the linker that the optimization is safe
by using the R_PPC64_PCREL_OPT relocation.
This patch extends the .reloc directive to allow the following setup
pld 3, vec@got@pcrel(0), 1
.Lpcrel1=.-8
... More instructions possible here ...
.reloc .Lpcrel1,R_PPC64_PCREL_OPT,.-.Lpcrel1
lwa 3, 4(3)
Reviewers: nemanjai, lei, hfinkel, sfertile, efriedma, tstellar, grosbach, MaskRay
Reviewed By: nemanjai, MaskRay
Differential Revision: https://reviews.llvm.org/D79625
PTX does not support negative values in .bNN data directives and we must
typecast such values to unsigned before printing them.
MCAsmInfo can now specify whether such casting is necessary for particular
target.
Differential Revision: https://reviews.llvm.org/D83423
Accounting for the fact that Wasm function indices are 32-bit, but in wasm64 we want uniform 64-bit pointers.
Includes reloc types for 64-bit table indices.
Differential Revision: https://reviews.llvm.org/D83729
For `.reloc offset, *, *`, currently offset can be a constant or symbol.
This patch makes it support any expression which can be folded to sym+constant.
Reviewed By: stefanp
Differential Revision: https://reviews.llvm.org/D83751
Replace mutiple `if else` clauses with a `switch` clause and remove redundant checks. Before this patch, we need to add a statement like `if(!isa<MCxxxFragment>(Frag)) ` here each time we add a new kind of `MCEncodedFragment` even if it has no fixups. After this patch, we don't need to do that.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D83366
Summary:
Add support for user-defined types to MasmParser, including initialization and field access.
Known issues:
- Omitted entry initializers (e.g., <,0>) do not work consistently for nested structs/arrays.
- Size checking/inference for values with known types is not yet implemented.
- Some ml64.exe syntaxes for accessing STRUCT fields are not recognized.
- `[<register>.<struct name>].<field>`
- `[<register>[<struct name>.<field>]]`
- `(<struct name> PTR [<register>]).<field>`
- `[<variable>.<struct name>].<field>`
- `(<struct name> PTR <variable>).<field>`
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D75306
Summary:
Change MCExpr to support Aurora VE's modifiers. Change asmparser to use
existing MCExpr parser (parseExpression) to parse an expression contining
symbols with modifiers and offsets. Also add several regression tests
of MC layer.
Reviewers: simoll, k-ishizaka
Reviewed By: simoll
Subscribers: hiraditya, llvm-commits
Tags: #llvm, #ve
Differential Revision: https://reviews.llvm.org/D83170
Summary:
When a desired symbol name contains invalid character that the
system assembler could not process, we need to emit .rename
directive in assembly path in order for that desired symbol name
to appear in the symbol table.
Reviewed By: hubert.reinterpretcast, DiggerLin, daltenty, Xiangling_L
Differential Revision: https://reviews.llvm.org/D82481
Summary:
When parsing 64-bit MASM, treat memory operands with unspecified base register as RIP-based.
Documented in several places, including https://software.intel.com/en-us/articles/introduction-to-x64-assembly: "Unfortunately, MASM does not allow this form of opcode, but other assemblers like FASM and YASM do. Instead, MASM embeds RIP-relative addressing implicitly."
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D73227
This change lets LLVM use the LC_BUILD_VERSION command when building for macOS 10.14, iOS 12, tvOS 12, and watchOS 5.
Additionally, this change ensures that new platforms like Apple Silicon macOS / Mac Catalyst,
and simulators running on Apple Silicon alway use LC_BUILD_VERSION with the OS version set to the
minimum supported OS version if the deployment target version is older.
Differential Revision: https://reviews.llvm.org/D82836
Give up folding an expression if the fragment of one of the operands
would require laying out a fragment already being laid out. This
prevents hitting an infinite recursion when a fill size expression
refers to a later fragment since computing the offset of that fragment
would require laying out the fill fragment and thus computing its size
expression.
Reviewed By: echristo
Differential Revision: https://reviews.llvm.org/D79570
Currently, section indices may be passed uninitialized by value if
writing the section fails. Removes section indices form class
initialization and returns them from the write{Code,Data}Section
function calls instead.
Patch by Gui Andrade!
Differential Revision: https://reviews.llvm.org/D81702
This features matches ELFAsmParser and makes it possible to use `.section ".llvm.call-graph-profile","n"`
Reviewed By: zequanwu
Differential Revision: https://reviews.llvm.org/D82240
The patch renames MakeStartMinusEndExpr() to makeEndMinusStartExpr() to
better reflect an expression it creates and fix a naming style issue.
Differential Revision: https://reviews.llvm.org/D82079
Compiling assembly files when newlines are reduced to line markers within a `.macro` context will generate wrong information in `.debug_line` section.
This patch fixes this issue by evaluating line markers within the macro scope but not when they are used and evaluated.
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D80381
Note that .eh_frame sections are generated in the 32-bit format even
when debug sections are 64-bit, for compatibility reasons. They use
relative references between entries, so they hardly benefit from the
64-bit format.
Differential Revision: https://reviews.llvm.org/D81149
DW_FORM_sec_offset was introduced in DWARFv4, so, for 64-bit DWARFv3,
DW_FORM_data8 should be used instead.
Differential Revision: https://reviews.llvm.org/D81148
The patch enables producing DWARF64 compilation units and fixes
generating references to .debug_abbrev and .debug_line sections.
A similar change for .debug_ranges/.debug_rnglists will be added
in a forthcoming patch.
Differential Revision: https://reviews.llvm.org/D81145
The patch adds an option `--dwarf64` to instruct a tool to generate
debug information in the 64-bit DWARF format. There is no real
implementation yet, only a few compatibility checks.
Differential Revision: https://reviews.llvm.org/D81143
This adds 4 new reloc types.
A lot of code that previously assumed any memory or offset values could be contained in a uint32_t (and often truncated results from functions returning 64-bit values) have been upgraded to uint64_t. This is not comprehensive: it is only the values that come in contact with the new relocation values and their dependents.
A new tablegen mapping was added to automatically upgrade loads/stores in the assembler, which otherwise has no way to select for these instructions (since they are indentical other than for the offset immediate). It follows a similar technique to https://reviews.llvm.org/D53307
Differential Revision: https://reviews.llvm.org/D81704
Summary:
This commit slightly modifies the MCDisassembler, and llvm-objdump to
allow targets to also decode entire symbols.
WebAssembly uses the onSymbolStart hook it to decode preludes.
WebAssembly partially disassembles the symbol in its target specific
way; and then falls back to the normal flow of llvm-objdump.
AMDGPU needs it to decode kernel descriptors entirely, and move to the
next symbol.
This commit is to split the above task into 2.
- Changes to llvm-objdump and MC-layer without breaking WebAssembly code
[ this commit ]
- AMDGPU's implementation of onSymbolStart that decodes kernel
descriptors. [ https://reviews.llvm.org/D80713 ]
Reviewers: scott.linder, t-tye, sunfish, arsenm, jhenderson, MaskRay, aardappel
Reviewed By: scott.linder, jhenderson, aardappel
Subscribers: bcain, dschuff, wdng, tpr, sbc100, jgravelle-google, hiraditya, aheejin, MaskRay, rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80512
SUMMARY:
Since we deal with aix emitLinkage in the PPCAIXAsmPrinter::emitLinkage() in the patch https://reviews.llvm.org/D75866. It do not go to AsmPrinter::emitLinkage() any more, we clean up some aix related code in the AsmPrinter::emitLinkage()
Reviewers: Jason liu
Differential Revision: https://reviews.llvm.org/D81613
SUMMARY:
in the aix assembly , it do not have .hidden and .protected directive.
in current llvm. if a function or a variable which has visibility attribute, it will generate something like the .hidden or .protected , it can not recognize by aix as.
in aix assembly, the visibility attribute are support in the pseudo-op like
.extern Name [ , Visibility ]
.globl Name [, Visibility ]
.weak Name [, Visibility ]
in this patch, we implement the visibility attribute for the global variable, function or extern function .
for example.
extern __attribute__ ((visibility ("hidden"))) int
bar(int* ip);
__attribute__ ((visibility ("hidden"))) int b = 0;
__attribute__ ((visibility ("hidden"))) int
foo(int* ip){
return (*ip)++;
}
the visibility of .comm linkage do not support , we will have a separate patch for it.
we have the unsupported cases ("default" and "internal") , we will implement them in a a separate patch for it.
Reviewers: Jason Liu ,hubert.reinterpretcast,James Henderson
Differential Revision: https://reviews.llvm.org/D75866
If there are more than 65534 relocation entries in a single section,
we should generate an overflow section.
Since we don't support overflow section for now, we should generate
an error.
Differential revision: https://reviews.llvm.org/D81104
Without this change, names start with 'L' will get created as
temporary symbol in MCContext::createSymbol.
Some other potential prefix considered:
.L, does not work for AIX, as a function start with L will end
up with .L as prefix for its function entry point.
..L could work, but it does not play well with the convention
on AIX that anything start with '.' are considered as entry point.
L. could work, but not sure if it's safe enough, as it's possible
to have suffixes like .something append to a plain L, giving L.something
which is not necessarily a temporary.
That's why we picked L.. for now.
Differential Revision: https://reviews.llvm.org/D80831
Summary:
The standard data emission directives (e.g. .short, .long) in the AIX assembler
have the unintended consequence of aligning their output to the natural byte
boundary. This cause problems because we aren't expecting behavior from the
Data*bitsDirectives, so the final alignment of data isn't correct in some cases
on AIX.
This patch updated the Data*bitsDirectives to use .vbyte pseudo-ops instead to emit the
data, since we will emit the .align directives as needed. We update the existing
testcases and add a test for emission of struct data.
Reviewers: hubert.reinterpretcast, Xiangling_L, jasonliu
Reviewed By: hubert.reinterpretcast, jasonliu
Subscribers: wuzish, nemanjai, hiraditya, kbarton, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80934
This patch adds support for emission of following DWARFv5 macro
forms in .debug_macro.dwo section:
- DW_MACRO_start_file
- DW_MACRO_end_file
- DW_MACRO_define_strx
- DW_MACRO_undef_strx
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D78866
Previously in the object format we punted on this and simply wrote
zeros (and didn't include the function in the elem segment). With
this change we write a meaningful value which is the segment
relative table index of the associated function.
This matches the that wasm-ld produces in `-r` mode. This inconsistency
between the output the MC object writer and the wasm-ld object
writer could cause warnings to be emitted when reading back in the
output of `wasm-ld -r`. See:
https://github.com/emscripten-core/emscripten/issues/11217
This only applies to this one relocation type which is only generated
when compiling in PIC mode.
Differential Revision: https://reviews.llvm.org/D80774
SUMMARY:
when there are two symbol has the same address. llvm-objdump -D -symbol-description will select symbol based on the following rule:
1. using Label first if there is a Label symbol.
2. If there is not Label, using a symbol which has Storage Mapping class.
3. if more than one symbol has storage mapping class, put the TC0 has the low priority, for other storage mapping class , compare based on the value.
Reviewers: James Henderson ,hubert.reinterpretcast,
Differential Revision: https://reviews.llvm.org/D78387
Negations are incorrectly added in numerous places and the code just happens to work.
Also fix a missed DW_CFA_def_cfa_offset negation in c693b9c321d5a40d012340619674cf790c9ac86c:
ARMAsmBackendDarwin::generateCompactUnwindEncoding
To be consistent with other directives like '.comm', '.lcomm', we remove
the spaces after the comma for '.csect' on AIX.
Differential Revision: https://reviews.llvm.org/D80247
The function does not need an MCStreamer per se; it was used only to get
access to the MCContext.
Differential Revision: https://reviews.llvm.org/D80205
In D49466, sys::path::replace_path_prefix was used instead startswith for -f[macro/debug/file]-prefix-map options.
However those were reverted later (commit rG3bb24bf25767ef5bbcef958b484e7a06d8689204) due to broken Windows tests.
This patch restores those replace_path_prefix calls.
It also modifies the prefix matching to be case-insensitive under Windows.
Differential Revision : https://reviews.llvm.org/D76869
Summary:
This patch tries to emit the correct alignment result for both
object file generation path and assembly path.
Reviewed by: hubert.reinterpretcast, DiggerLin, daltenty
Differential Revision: https://reviews.llvm.org/D79127
Summary:
This patch introduces the constants defined to identify DWARF sections
in XCOFF into `llvm/BinaryFormat/XCOFF.h` and adds (NFC) placeholder
code to `llvm/lib/MC/MCObjectFileInfo.cpp` where the DWARF sections for
XCOFF are to be set up.
Reviewers: jasonliu, sfertile, daltenty, DiggerLin, Xiangling_L
Reviewed By: jasonliu, sfertile, DiggerLin
Differential Revision: https://reviews.llvm.org/D79220
The function MCSymbolRefExpr::getVariantKindForName was missing the entry for
VK_PPC_GOT_PCREL. This patch adds the missing entry.
Differential Revision: https://reviews.llvm.org/D79015
The setting of `MCAsmInfo` properties for XCOFF got split between
`MCAsmInfoXCOFF` and `PPCXCOFFMCAsmInfo`. Except for the properties that
are dependent on the target information being passed via the
constructor, the properties being set in `PPCXCOFFMCAsmInfo` had no
fundamental reason for being treated as specific for XCOFF on PowerPC.
Indeed, the property that might be considered more specific to PowerPC,
`NeedsFunctionDescriptors`, was set in `MCAsmInfoXCOFF`.
XCOFF being specific to PowerPC anyway, this patch consolidates the
setting of the properties into `MCAsmInfoXCOFF` except for the cases
that are dependent on the information provided via the
`PPCXCOFFMCAsmInfo` constructor.
This patch also reorders the assignments to the fields to match the
declaration order in `MCAsmInfo`.
This change add support for defined wasm globals in the .s format,
the MC layer, and wasm-ld
Currently there is no support custom initialization and all wasm
globals are initialized to zero.
Fixes: PR45742
Differential Revision: https://reviews.llvm.org/D79137
Chen Zheng