- 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
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 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
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.
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
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.
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
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
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
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 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
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
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
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
Anirudh Prasad