[clang-doc] Support deep copy between arenas for merging
Upcoming changes to the merge step will necessitate that we clear the
transient arenas and merge new items into the persistent arena. However
there are some challenges with that, as the existing types typically
don't want to be copied. We introduce some new APIs to simplify that
task and ensure we don't accidentally leak memory.
On the performance front, we reclaim about 2% of the overhead, bringing
the cumulative overhead from the series of patches down to about 7% over
the baseline.
| Metric | Baseline | Prev | This | Culm% | Seq% |
| :--- | :--- | :--- | :--- | :--- | :--- |
| Time | 920.5s | 1014.5s | 991.5s | +7.7% | -2.3% |
| Memory | 86.0G | 39.9G | 40.0G | -53.4% | +0.3% |
| Benchmark | Baseline | Prev | This | Culm% | Seq% |
| :--- | :--- | :--- | :--- | :--- | :--- |
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[clang-doc] Move Info types into arenas
Info types used to own significant chunks of data. As we move these into
local arenas, these types must be trivially destructible, to avoid
leaking resources when the arena is reset. Unfortunaly, there isn't a
good way to transition all the data types one at a time, since most of
them are tied together in some way. Further, as they're now allocated in
the arenas, they often cannot be treated the same way, and even the
aliases and interfaces put in pLace to simplify the transition cannot
cover the full range of changes required.
We also use some SFINAE tricks to avoid adding boilerplate for helper
APIs, we'd otherwise ahve to support
Though it introduces some additional churn, we also try to keep tests
from using arena allocation as much as possible, since this is not
required to test the implementation of the library. As much of the test
code needed to be rewritten anyway, we take the opportunity to
transition now.
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[clang-doc] Make CommentInfo arena allocated
This patch move the CommentInfo type into the arena. It updates block
handling to collect child info types and serialize the array in one
shot.
We also clean up the test code to avoid using the arenas in the tests.
This has the upside of making the test more hermetic, and avoids churn
in the related code as the allocation API interfaces evolve.
Performance and memory usage regress slightly. This is somewhat expected
as we do not yet aggressively release short term memory during merge
operations. Future patches will reclaim this overhead.
| Metric | Baseline | Prev | This | Culm% | Seq% |
| :--- | :--- | :--- | :--- | :--- | :--- |
| Time | 920.5s | 998.5s | 1010.5s | +9.8% | +1.2% |
| Memory | 86.0G | 43.8G | 47.8G | -44.4% | +9.2% |
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[clang-doc] Simplify parsing and reading bitcode blocks
Much of the logic int he readBlock implementation is boilerplate, and is
repeated for each implementation/specialization. This will become much
worse as we introduce new custom block reading logic as we migrate
towards arena allocation. In preparation for that, we're introducing the
change in logic now, which should make later refactoring much more
straightforward.
[clang-doc] Consolidate merging logic
As we migrate things in the arena, this logic may get more complex.
Factoring it out now, will give clear extension points to make this
easier to manage.
[clang-doc] Move non-arena allocated types off the OwnedPtr alias
Some types should not be using this alias, which was over applied to
APIs that wont participate in arena style allocation. This patch
restores them to their correct spelling.
[clang-doc] Enforce arena allocated types are trivially destructible
We can enforce at compile-time that the types we want to place in the
arenas are always safe to allocate there.
[clang-doc] Merge data into persistent memory
We have a need for persistent memory for the final info. Since each
group processes a single USR at a time, every USR is only ever processed by
a single thread from the thread pool. This means that we can keep per
thread persistent storage for all the info. There is significant
duplicated data between all the serialized records, so we can just merge
the final/unique items into the persistent arena, and clear out the
scratch/transient arena as we process each record in the bitcode.
The patch adds some APIs to help with managing the data, merging, and
allocation of data in the correct arena. It also safely merges and deep
copies data from the transient arenas into persistent storage that is
never reset until the program completes.
This patch reduces memory by another % over the previous patches,
bringing the total savings over the baseline to 57%. Runtime performance
and benchmarks stay mostly flat with modest improvements.
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[clang-doc] Introduce TransientArena for short lived allocations
With strings interned, we can move the StringRefs in various Info
structs into a new short lived arena. This change migrates the remaining
SmallVectors in CommentInfo to use an ArrayRef backed by the new
transient arena.
This results in further minor reductions in overall memory usage, but no
significant effect on runtime performance.
| Metric | Baseline | Prev | This | Culm% | Seq% |
| :--- | :--- | :--- | :--- | :--- | :--- |
| Time | 920.5s | 1011.0s | 1005.7s | +9.2% | -0.5% |
| Memory | 86.0G | 44.9G | 42.1G | -51.0% | -6.2% |
| Benchmark | Baseline | Prev | This | Culm% | Seq% |
| :--- | :--- | :--- | :--- | :--- | :--- |
| BM_BitcodeReader_Scale/10 | 67.9us | 70.0us | 68.6us | +1.0% | -2.0% |
| BM_BitcodeReader_Scale/10000 | 70.5ms | 21.3ms | 21.3ms | -69.8% | -0.0% |
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[ELF] Enable parallel relocation scanning for -z nocombreloc and PPC64 (#190309)
The `bool serial` condition in scanRelocations disabled parallelism for
three cases: -z nocombreloc, MIPS, and PPC64. Resolve two cases:
- nocombreloc: .rela.dyn is now always created with combreloc=true so
non-relative relocations are sorted deterministically. Since
#187964 already separates relative relocations unconditionally,
the only remaining effect of -z nocombreloc is suppressing
DT_RELACOUNT (gated on ctx.arg.zCombreloc in DynamicSection).
- PPC64: After #181496 moved scanning into scanSectionImpl, the
sole thread-unsafe access is ctx.ppc64noTocRelax (DenseSet::insert).
Protect it with ctx.relocMutex, which is already used for rare
operations during parallel scanning.
MIPS retains serial scanning due to `MipsGotSection` mutations.
Merge tag 'v7.0-rc6-smb3-client-fix' of git://git.samba.org/sfrench/cifs-2.6
Pull smb client fix from Steve French:
- Fix potential out of bounds read in mount
* tag 'v7.0-rc6-smb3-client-fix' of git://git.samba.org/sfrench/cifs-2.6:
fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath
upmendex: update to 1.22
part of TeXlive 2026
* Experimental support for Brahmic scripts (Bengali, Gurmukhi, Gujarati,
Kannada, Lao, Malayalam, Oriya, Sinhala, Tamil, Telugu).
xetex to 0.999998
part of TeXlive 2026
* When the “Infinite glue shrinkage” error is ignored (see the 2025 release
notes), the word “error” is no longer included in the output, and the message
is written only to the log file. This was a source of minor confusion and false
positives.
