Make the fixed-size part of MCFragment append-only to support allocating
content as trailing data. Update CodeView callers to use setVarContents
instead of setContents. Remove unused setFixups.
... by eagerly allocating an empty fragment when adding a fragment
with a variable-size tail.
X86AsmBackend, The JCC erratum mitigation and x86-pad-for-align set a
flag for FT_Relaxable, which needs to be moved to emitInstructionBegin.
```
if (CF->getKind() == MCFragment::FT_Relaxable)
CF->setAllowAutoPadding(canPadInst(Inst, OS));
```
Follow-up to #148544
Refactor the fragment representation of `push rax; jmp foo; nop; jmp foo`,
previously encoded as
`MCDataFragment(nop); MCRelaxableFragment(jmp foo); MCDataFragment(nop); MCRelaxableFragment(jmp foo)`,
to
```
MCFragment(fixed: push rax, variable: jmp foo)
MCFragment(fixed: nop, variable: jmp foo)
```
Changes:
* Eliminate MCEncodedFragment, moving content and fixup storage to MCFragment.
* The new MCFragment contains a fixed-size content (similar to previous
MCDataFragment) and an optional variable-size tail.
* The variable-size tail supports FT_Relaxable, FT_LEB, FT_Dwarf, and
FT_DwarfFrame, with plans to extend to other fragment types.
dyn_cast/isa should be avoided for the converted fragment subclasses.
* In `setVarFixups`, source fixup offsets are relative to the variable part's start.
Stored fixup (in `FixupStorage`) offsets are relative to the fixed part's start.
A lot of code does `getFragmentOffset(Frag) + Fixup.getOffset()`,
expecting the fixup offset to be relative to the fixed part's start.
* HexagonAsmBackend::fixupNeedsRelaxationAdvanced needs to know the
associated instruction for a fixup. We have to add a `const MCFragment &` parameter.
* In MCObjectStreamer, extend `absoluteSymbolDiff` to apply to
FT_Relaxable as otherwise there would be many more FT_DwarfFrame
fragments in -g compilations.
https://llvm-compile-time-tracker.com/compare.php?from=28e1473e8e523150914e8c7ea50b44fb0d2a8d65&to=778d68ad1d48e7f111ea853dd249912c601bee89&stat=instructions:u
```
stage2-O0-g instructins:u geomeon (-0.07%)
stage1-ReleaseLTO-g (link only) max-rss geomean (-0.39%)
```
```
% /t/clang-old -g -c sqlite3.i -w -mllvm -debug-only=mc-dump &| awk '/^[0-9]+/{s[$2]++;tot++} END{print "Total",tot; n=asorti(s, si); for(i=1;i<=n;i++) print si[i],s[si[i]]}'
Total 59675
Align 2215
Data 29700
Dwarf 12044
DwarfCallFrame 4216
Fill 92
LEB 12
Relaxable 11396
% /t/clang-new -g -c sqlite3.i -w -mllvm -debug-only=mc-dump &| awk '/^[0-9]+/{s[$2]++;tot++} END{print "Total",tot; n=asorti(s, si); for(i=1;i<=n;i++) print si[i],s[si[i]]}'
Total 32287
Align 2215
Data 2312
Dwarf 12044
DwarfCallFrame 4216
Fill 92
LEB 12
Relaxable 11396
```
Pull Request: https://github.com/llvm/llvm-project/pull/148544
`StrTabFragment` created due to `.cv_stringtable` is not placed directly
into a section. This requires a funky ~CodeViewContext and does not fit
well with the future that moves MCFragment storage out-of-line.
It is almost always simpler to use {} instead of std::nullopt to
initialize an empty ArrayRef. This patch changes all occurrences I could
find in LLVM itself. In future the ArrayRef(std::nullopt_t) constructor
could be deprecated or removed.
#95197 and 75006466296ed4b0f845cbbec4bf77c21de43b40 eliminated all raw
`new MCXXXFragment`. We can now place fragments in a bump allocator.
In addition, remove the dead `Kind == FragmentType(~0)` condition.
~CodeViewContext may call `StrTabFragment->destroy()` and need to be
reset before `FragmentAllocator.Reset()`.
Tested by llvm/test/MC/COFF/cv-compiler-info.ll using asan.
Pull Request: https://github.com/llvm/llvm-project/pull/96402
`allocFragment` might be changed to a placement new when the allocation
strategy changes.
`allocInitialFragment` is to deduplicate the following pattern
```
auto *F = new MCDataFragment();
Result->addFragment(*F);
F->setParent(Result);
```
Pull Request: https://github.com/llvm/llvm-project/pull/95197
Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class as opposed to an
enum. This patch replaces support::{big,little,native} with
llvm::endianness::{big,little,native}.
Issue Details:
When building up line information for CodeView debug info, LLVM attempts to gather the "range" of instructions within a function as these are printed together in a single record. If there is an inlined function, then those lines are attributed to the original function to enable generating `S_INLINESITE` records. However, this thus requires there to be instructions from the inlining function after the inlined function otherwise the instruction range would not include the inlined function.
Fix Details:
Include any inlined functions when finding the extent of a function in `getFunctionLineEntries`
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D159226
This code was added in 408b5e660300f9, but neither the return value nor
`Res` was used in the following code.
Differential Revision: https://reviews.llvm.org/D149584
Use deduction guides instead of helper functions.
The only non-automatic changes have been:
1. ArrayRef(some_uint8_pointer, 0) needs to be changed into ArrayRef(some_uint8_pointer, (size_t)0) to avoid an ambiguous call with ArrayRef((uint8_t*), (uint8_t*))
2. CVSymbol sym(makeArrayRef(symStorage)); needed to be rewritten as CVSymbol sym{ArrayRef(symStorage)}; otherwise the compiler is confused and thinks we have a (bad) function prototype. There was a few similar situation across the codebase.
3. ADL doesn't seem to work the same for deduction-guides and functions, so at some point the llvm namespace must be explicitly stated.
4. The "reference mode" of makeArrayRef(ArrayRef<T> &) that acts as no-op is not supported (a constructor cannot achieve that).
Per reviewers' comment, some useless makeArrayRef have been removed in the process.
This is a follow-up to https://reviews.llvm.org/D140896 that introduced
the deduction guides.
Differential Revision: https://reviews.llvm.org/D140955
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
There's a few relevant forward declarations in there that may require downstream
adding explicit includes:
llvm/MC/MCContext.h no longer includes llvm/BinaryFormat/ELF.h, llvm/MC/MCSubtargetInfo.h, llvm/MC/MCTargetOptions.h
llvm/MC/MCObjectStreamer.h no longer include llvm/MC/MCAssembler.h
llvm/MC/MCAssembler.h no longer includes llvm/MC/MCFixup.h, llvm/MC/MCFragment.h
Counting preprocessed lines required to rebuild llvm-project on my setup:
before: 1052436830
after: 1049293745
Which is significant and backs up the change in addition to the usual benefits of
decreasing coupling between headers and compilation units.
Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D119244
Testing with debuggers shows that our previous behavior was correct.
The reason I thought MSVC did things differently is that MSVC prefers to
use the 0xB combined code offset and code length update opcode when
inline sites are discontiguous.
Keep the test changes, and update the llvm-pdbutil inline line table
dumper to account for this new interpretation of the opcodes.
llvm-svn: 362277
After improving the inline line table dumper in llvm-pdbutil and looking
at MSVC's inline line tables, it is clear that setting the length of the
inlined code region does not update the code offset. This means that the
delta to the beginning of a new discontiguous inlined code region should
be calculated relative to the last code offset, excluding the length.
Implementing this is a one line fix for MC: simply don't update
LastLabel.
While I'm updating these test cases, switch them to use llvm-objdump -d
and llvm-pdbutil. This allows us to show offsets of each instruction and
correlate the line table offsets to the actual code.
llvm-svn: 362264
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
This was a pre-existing bug that could be triggered with assembly like
this:
.p2align 2
.LtmpN:
.cv_def_range "..."
I noticed this when attempting to change clang to emit aligned symbol
records.
llvm-svn: 349403
Now that we create the label at the point of the directive, we don't
need to set the "current CV location", and then later when we emit the
next instruction, create a label for it and emit it.
DWARF still defers the labels used in .debug_loc until the next
instruction or value, for reasons unknown.
llvm-svn: 340883
Provide some free functions to reduce verbosity of endian-writing
a single value, and replace the endianness template parameter with
a field.
Part of PR37466.
Differential Revision: https://reviews.llvm.org/D47032
llvm-svn: 332757
If no data or instructions are emitted after a location directive, we
should clear the cv_loc when we change sections, or it will be emitted
at the beginning of the next section. This violates our invariant that
all .cv_loc directives belong to the same section. Add clearer
assertions for this.
llvm-svn: 330884
We did this for inline call site line tables, but we hadn't done it for
regular function line tables yet. This patch copies that logic from
encodeInlineLineTable.
llvm-svn: 322905
We can probably take this a step further since the only
user of the isUsed flag is AsmParser it should probably
be doing this explicitly. For now this is a step in the
right direction though.
Differential Revision: https://reviews.llvm.org/D41971
llvm-svn: 322386
This reverts commit 6389e7aa724ea7671d096f4770f016c3d86b0d54.
There is a bug in this implementation where the string value of the
checksum is outputted, instead of the actual hex bytes. Therefore the
checksum is incorrect, and this prevent pdbs from being loaded by visual
studio. Revert this until the checksum is emitted correctly.
llvm-svn: 313431
Summary:
The checksums had already been placed in the IR, this patch allows
MCCodeView to actually write it out to an MCStreamer.
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D37157
llvm-svn: 313374
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
llvm-svn: 304864
This is the beginning of an effort to move the codeview yaml
reader / writer into ObjectYAML so that it can be shared.
Currently the only consumer / producer of CodeView YAML is
llvm-pdbdump, but CodeView can exist outside of PDB files, and
indeed is put into object files and passed to the linker to
produce PDB files. Furthermore, there are subtle differences
in the types of records that show up in object file CodeView
vs PDB file CodeView, but they are otherwise 99% the same.
By having this code in ObjectYAML, we can have llvm-pdbdump
reuse this code, while teaching obj2yaml and yaml2obj to use
this syntax for dealing with object files that can contain
CodeView.
This patch only adds support for CodeView type information
to ObjectYAML. Subsequent patches will add support for
CodeView symbol information.
llvm-svn: 304248
There is a lot of duplicate code for printing line info between
YAML and the raw output printer. This introduces a base class
that can be shared between the two, and makes some minor
cleanups in the process.
llvm-svn: 301728
