This adds the `-Z json-target-spec` CLI flag to assist with using custom
`.json` target spec files. `rustc` recently switched so that it requires
`-Z unstable-options` when using custom spec files
(rust-lang/rust#151534). This can make it rather
awkward to use spec files with cargo because it then requires setting
RUSTFLAGS and RUSTDOCFLAGS to pass `-Zunstable-options`. It also ends up
causing some confusing error messages.

Now, using `--target` with `.json` extension files generates an error
that explains you need `-Zjson-target-spec`. The only thing this flag
does is disable that error, and automatically passes
`-Zunstable-options` with the `--target` flag.

This does not 100% cover json target spec files, because they can be
placed in RUST_TARGET_PATH or the sysroot, and `rustc` will
automatically search for them (without the `.json` extension in the
`--target` arg). The user will just need to use RUSTFLAGS/RUSTDOCFLAGS
in that situation (but I expect that to be rare).

The majority of this change is changing `CompileTarget::new` to take a
flag if `-Zjson-target-spec` is enabled, and then threading through all
the places that call it. `CompileTarget::new` is responsible for
generating an error if json is used without the Z flag.

This adds the `-Z json-target-spec` CLI flag to assist with using custom
`.json` target spec files. `rustc` recently switched so that it requires
`-Z unstable-options` when using custom spec files
(rust-lang/rust#151534). This can make it rather
awkward to use spec files with cargo because it then requires setting
RUSTFLAGS and RUSTDOCFLAGS to pass `-Zunstable-options`. It also ends up
causing some confusing error messages.

Now, using `--target` with `.json` extension files generates an error
that explains you need `-Zjson-target-spec`. The only thing this flag
does is disable that error, and automatically passes
`-Zunstable-options` with the `--target` flag.

This does not 100% cover json target spec files, because they can be
placed in RUST_TARGET_PATH or the sysroot, and `rustc` will
automatically search for them (without the `.json` extension in the
`--target` arg). The user will just need to use RUSTFLAGS/RUSTDOCFLAGS
in that situation (but I expect that to be rare).

The majority of this change is changing `CompileTarget::new` to take a
flag if `-Zjson-target-spec` is enabled, and then threading through all
the places that call it. `CompileTarget::new` is responsible for
generating an error if json is used without the Z flag.

This adds the `-Z json-target-spec` CLI flag to assist with using custom
`.json` target spec files. `rustc` recently switched so that it requires
`-Z unstable-options` when using custom spec files
(rust-lang/rust#151534). This can make it rather
awkward to use spec files with cargo because it then requires setting
RUSTFLAGS and RUSTDOCFLAGS to pass `-Zunstable-options`. It also ends up
causing some confusing error messages.

See the individual commits for more details.

This ended up being a larger diff than I wanted. I'm not 100% certain
this is worth it, but I think it significantly improves the experience
using `.json` files, so I I'm leaning towards it.

### How to test and review this PR?

Testing can be done with `rustc` built from
rust-lang/rust#151534 to ensure that everything
passes after that PR (including setting `CARGO_RUN_BUILD_STD_TESTS=1`).

This adds the `-Z json-target-spec` CLI flag to assist with using custom
`.json` target spec files. `rustc` recently switched so that it requires
`-Z unstable-options` when using custom spec files
(rust-lang/rust#151534). This can make it rather
awkward to use spec files with cargo because it then requires setting
RUSTFLAGS and RUSTDOCFLAGS to pass `-Zunstable-options`. It also ends up
causing some confusing error messages.

See the individual commits for more details.

This ended up being a larger diff than I wanted. I'm not 100% certain
this is worth it, but I think it significantly improves the experience
using `.json` files, so I I'm leaning towards it.

Testing can be done with `rustc` built from
rust-lang/rust#151534 to ensure that everything
passes after that PR (including setting `CARGO_RUN_BUILD_STD_TESTS=1`).

…json-again, r=chenyukang

target: fix destabilising target-spec-json

cc rust-lang#151528

rust-lang#150151 missed a case and didn't entirely destabilise target-spec-json - this patch corrects that.

Closes rust-lang#71009

…json-again, r=chenyukang

target: fix destabilising target-spec-json

cc rust-lang#151528

rust-lang#150151 missed a case and didn't entirely destabilise target-spec-json - this patch corrects that.

Closes rust-lang#71009

Rollup of 4 pull requests

Successful merges:

 - #147436 (slice/ascii: Optimize `eq_ignore_ascii_case` with auto-vectorization)
 - #151390 (Reintroduce `QueryStackFrame` split.)
 - #151534 (target: fix destabilising target-spec-json)
 - #151692 (Try to reduce rustdoc GUI tests flakyness)

…json-again, r=chenyukang

target: fix destabilising target-spec-json

cc rust-lang#151528

rust-lang#150151 missed a case and didn't entirely destabilise target-spec-json - this patch corrects that.

Closes rust-lang#71009

…json-again, r=chenyukang

target: fix destabilising target-spec-json

cc rust-lang#151528

rust-lang#150151 missed a case and didn't entirely destabilise target-spec-json - this patch corrects that.

Closes rust-lang#71009

…json-again, r=chenyukang

target: fix destabilising target-spec-json

cc rust-lang#151528

rust-lang#150151 missed a case and didn't entirely destabilise target-spec-json - this patch corrects that.

Closes rust-lang#71009

…uwer

Rollup of 11 pull requests

Successful merges:

 - #150605 (skip codegen for intrinsics with big fallback bodies if backend does not need them)
 - #150992 (link modifier `export-symbols`: export all global symbols from selected uptream c static libraries)
 - #151534 (target: fix destabilising target-spec-json)
 - #152088 (rustbook/README.md: add missing `)`)
 - #151526 (Fix autodiff codegen tests)
 - #151810 (citool: report debuginfo test statistics)
 - #152065 (Convert to inline diagnostics in `rustc_ty_utils`)
 - #152068 (Convert to inline diagnostics in `rustc_resolve`)
 - #152070 (Convert to inline diagnostics in `rustc_pattern_analysis`)
 - #152072 (Convert to inline diagnostics in `rustc_monomorphize`)
 - #152083 (Fix set_times_nofollow for directory on windows)

Failed merges:

 - #152069 (Convert to inline diagnostics in `rustc_privacy`)

…json-again, r=chenyukang

target: fix destabilising target-spec-json

cc rust-lang#151528

rust-lang#150151 missed a case and didn't entirely destabilise target-spec-json - this patch corrects that.

Closes rust-lang#71009

…json-again, r=chenyukang

target: fix destabilising target-spec-json

cc rust-lang#151528

rust-lang#150151 missed a case and didn't entirely destabilise target-spec-json - this patch corrects that.

Closes rust-lang#71009

…uwer

Rollup of 12 pull requests

Successful merges:

 - #150992 (link modifier `export-symbols`: export all global symbols from selected uptream c static libraries)
 - #151534 (target: fix destabilising target-spec-json)
 - #152088 (rustbook/README.md: add missing `)`)
 - #151526 (Fix autodiff codegen tests)
 - #151810 (citool: report debuginfo test statistics)
 - #151952 (Revert doc attribute parsing errors to future warnings)
 - #152065 (Convert to inline diagnostics in `rustc_ty_utils`)
 - #152066 (Convert to inline diagnostics in `rustc_session`)
 - #152069 (Convert to inline diagnostics in `rustc_privacy`)
 - #152072 (Convert to inline diagnostics in `rustc_monomorphize`)
 - #152083 (Fix set_times_nofollow for directory on windows)
 - #152102 (Convert to inline diagnostics in all codegen backends)

Failed merges:

 - #152068 (Convert to inline diagnostics in `rustc_resolve`)
 - #152070 (Convert to inline diagnostics in `rustc_pattern_analysis`)

Rollup merge of #151534 - davidtwco:destabilise-target-spec-json-again, r=chenyukang

target: fix destabilising target-spec-json

cc #151528

#150151 missed a case and didn't entirely destabilise target-spec-json - this patch corrects that.

Closes #71009

Custom target specifications are unstable, but starting with Rust 1.95.0,
`rustc` requires to explicitly pass `-Zunstable-options` to use them [1]:

    error: error loading target specification: custom targets are unstable and require `-Zunstable-options`
      |
      = help: run `rustc --print target-list` for a list of built-in targets

David (Rust compiler team lead), writes:

   "We're destabilising custom targets to allow us to move forward with
    build-std without accidentally exposing functionality that we'd like
    to revisit prior to committing to. I'll start a thread on Zulip to
    discuss with the RfL team how we can come up with an alternative
    for them."

Thus pass it.

Cc: David Wood <david@davidtw.co>
Cc: Wesley Wiser <wwiser@gmail.com>
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: rust-lang/rust#151534 [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

…custom-targets, r=scottmcm

compiletest: `-Zunstable-options` for json targets

bootstrap runs compiletest with synthetic custom targets when blessing `mir-opt` tests, but that no longer works after rust-lang#150151/rust-lang#151534 because `-Zunstable-options` is required

Contexts on [Zulips](https://rust-lang.zulipchat.com/#narrow/channel/122651-general/topic/custom.20targets.20are.20unstable.20and.20require.20.60-Zunstable-options.60).

…custom-targets, r=scottmcm

compiletest: `-Zunstable-options` for json targets

bootstrap runs compiletest with synthetic custom targets when blessing `mir-opt` tests, but that no longer works after rust-lang#150151/rust-lang#151534 because `-Zunstable-options` is required

Contexts on [Zulips](https://rust-lang.zulipchat.com/#narrow/channel/122651-general/topic/custom.20targets.20are.20unstable.20and.20require.20.60-Zunstable-options.60).

…custom-targets, r=scottmcm

compiletest: `-Zunstable-options` for json targets

bootstrap runs compiletest with synthetic custom targets when blessing `mir-opt` tests, but that no longer works after rust-lang#150151/rust-lang#151534 because `-Zunstable-options` is required

Contexts on [Zulips](https://rust-lang.zulipchat.com/#narrow/channel/122651-general/topic/custom.20targets.20are.20unstable.20and.20require.20.60-Zunstable-options.60).

…custom-targets, r=scottmcm

compiletest: `-Zunstable-options` for json targets

bootstrap runs compiletest with synthetic custom targets when blessing `mir-opt` tests, but that no longer works after rust-lang#150151/rust-lang#151534 because `-Zunstable-options` is required

Contexts on [Zulips](https://rust-lang.zulipchat.com/#narrow/channel/122651-general/topic/custom.20targets.20are.20unstable.20and.20require.20.60-Zunstable-options.60).

…custom-targets, r=scottmcm

compiletest: `-Zunstable-options` for json targets

bootstrap runs compiletest with synthetic custom targets when blessing `mir-opt` tests, but that no longer works after rust-lang#150151/rust-lang#151534 because `-Zunstable-options` is required

Contexts on [Zulips](https://rust-lang.zulipchat.com/#narrow/channel/122651-general/topic/custom.20targets.20are.20unstable.20and.20require.20.60-Zunstable-options.60).

Post-January 2026 nightly builds destabilized custom JSON target specs
(rust-lang/rust#151534), requiring an explicit -Zjson-target-spec flag
when passing a .json path to cargo --target. Without this, cargo-psp
fails with "`.json` target specs require -Zjson-target-spec" in CI.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Rollup merge of #152236 - davidtwco:compiletest-destabilise-custom-targets, r=scottmcm

compiletest: `-Zunstable-options` for json targets

bootstrap runs compiletest with synthetic custom targets when blessing `mir-opt` tests, but that no longer works after #150151/#151534 because `-Zunstable-options` is required

Contexts on [Zulips](https://rust-lang.zulipchat.com/#narrow/channel/122651-general/topic/custom.20targets.20are.20unstable.20and.20require.20.60-Zunstable-options.60).

* Add SDK platform abstractions: sync, cache, DMA, VFPU math, audio mixer, framebuffer, memory

Push reusable platform infrastructure into the SDK so every project benefits:

- psp::sync — Extract SpinMutex from debug.rs, add SpinRwLock, SPSC ring buffer, UncachedBox<T>
- psp::cache — Type-safe CachedPtr/UncachedPtr with flush/invalidate conversions
- psp::me::MeExecutor — High-level ME task submission with poll/wait and shared uncached state
- psp::dma — DmaTransfer handle with memcpy_dma/vram_blit_dma and sceDmac syscall bindings
- psp::simd — VFPU-accelerated Vec4/Mat4 math, color ops, easing functions
- psp::audio_mixer — Multi-channel PCM mixer with volume/panning/fade
- psp::framebuffer — DoubleBuffer, DirtyRect tracking, LayerCompositor
- psp::mem — Typed partition allocators (Partition2Alloc/Partition3Alloc) preventing ME pointer misuse

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Add Phase 2 SDK abstractions: io, thread, input, time + Phase 1 bugfixes

Bugfixes:
- Fix MeExecutor::submit() race condition by storing real_task/real_arg
  in dedicated MeSharedState fields instead of double-writing boot_params
- Fix audio_mixer volume mixing i32 overflow by using i64 intermediates
- Document sceDmacMemcpy synchronous behavior in dma.rs
- Remove unnecessary blanket #![allow(unsafe_op_in_unsafe_fn)] from simd.rs

New modules:
- psp::io - File (RAII), ReadDir iterator, read_to_vec, write_bytes, stat,
  create_dir, remove_file, remove_dir, rename
- psp::thread - ThreadBuilder, JoinHandle, spawn() with closure trampoline,
  sleep_ms, current_thread_id
- psp::input - Controller with press/release detection, analog deadzone
- psp::time - Instant, Duration, DateTime, FrameTimer

Enhanced modules:
- psp::sync - Add Semaphore and EventFlag kernel primitive wrappers

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Add Phase 3 SDK abstractions: display, power, audio, dialog, net, wlan, callback + bugfixes

Code review fixes:
- Wrap thread trampoline in catch_unwind for panic safety
- Simplify DmaTransfer to DmaResult (remove fake async API)
- Add #[repr(C, align(64))] to MeSharedState for cache coherency
- Document DoubleBuffer::new() init requirement
- Add vec4_length and vec4_distance to VFPU simd module

New SDK modules:
- psp::display - vblank sync, framebuffer get/set
- psp::power - clock control, battery info, AC detection
- psp::audio - AudioChannel with RAII reserve/release
- psp::callback - one-call exit callback setup
- psp::dialog - blocking message/confirm/error dialogs
- psp::wlan - WiFi hardware status
- psp::net - init/term, AP connect, TcpStream, UdpSocket, DNS resolve

Update examples to use new SDK modules:
- clock-speed, file-io, time, wlan, audio-tone, msg-dialog

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Add Phase 4 SDK abstractions: gu_ext, timer, usb, config, image, font + power extensions

New modules:
- psp::gu_ext — GU state snapshot/restore, 2D setup, SpriteVertex, SpriteBatch
- psp::timer — Alarm (one-shot closure trampoline) and VTimer (RAII wrapper)
- psp::usb — USB bus control and UsbStorageMode (RAII mass storage)
- psp::config — Binary key-value config persistence (RCFG format)
- psp::image — Hardware JPEG decode (sceJpeg*) and software BMP 24/32-bit decode
- psp::font — FontLib, Font, FontRenderer with VRAM glyph atlas (PsmT8 + CLUT)

Extended:
- psp::power — on_power_event (RAII callback), prevent_sleep, prevent_display_off

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Add 6 SDK showcase examples and expand README Platform SDK docs

New examples demonstrating Phase 1-4 SDK modules: thread-sync (SpinMutex
+ spawn), input-analog (Controller deadzone), config-save (RCFG format),
timer-alarm (Alarm + VTimer), net-http (WiFi + TcpStream), system-font
(FontLib + FontRenderer + GU). README revised: "High-Level Utilities"
replaced with comprehensive "Platform SDK" section (30+ modules in 9
domain categories), examples table updated with 6 new entries, structure
description updated.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Add Phase 5 SDK hardening: soundness fixes, correctness improvements, 6 new modules

Critical soundness fixes: UncachedBox Drop now calls drop_in_place, SpscQueue
Drop drains remaining items, PartitionAlloc tracks initialization state to
prevent UB on uninit Drop, Alarm restructured with AtomicU8 state machine
to eliminate interrupt-context allocation and TOCTOU race between Drop and
trampoline.

Medium correctness fixes: JoinHandle::join returns thread exit status,
dialog/connect_ap polling timeouts, config serialize overflow checks, power
callback cleanup on failure, callback registration error check, audio mixer
volume saturation, glyph atlas eviction bounds, SpriteBatch dcache flush,
sleep_ms overflow protection, removed dead mixer code.

Low-priority improvements: cached tick resolution const, deprecated
enable_home_button, Default impls, null-termination asserts, doc fixes,
remapf division-by-zero guard.

New modules: psp::http (RAII HTTP client), psp::mp3 (hardware MP3 decoder),
psp::osk (on-screen keyboard), psp::rtc (extended RTC operations),
psp::savedata (system save/load dialog), psp::system_param (system settings).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Replace deprecated enable_home_button() with setup_exit_callback() across all examples, add 4 new SDK examples

Migrate all 26 existing examples from the deprecated psp::enable_home_button()
to psp::callback::setup_exit_callback().unwrap(). Add 4 new examples showcasing
Phase 5 SDK modules: http-client (psp::http), savedata (psp::savedata),
osk-input (psp::osk), and rtc-sysinfo (psp::rtc + psp::system_param). Update
README code snippets and examples table accordingly.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix CI: add -Zjson-target-spec for newer nightly toolchains

Post-January 2026 nightly builds destabilized custom JSON target specs
(rust-lang/rust#151534), requiring an explicit -Zjson-target-spec flag
when passing a .json path to cargo --target. Without this, cargo-psp
fails with "`.json` target specs require -Zjson-target-spec" in CI.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix soundness and correctness issues from AI code review

- audio.rs: Validate buffer length in safe output_blocking/output_blocking_panning
  functions to prevent out-of-bounds reads by the PSP audio hardware. Store
  AudioFormat on AudioChannel to compute required buffer size.
- audio_mixer.rs: Fix fade_out/fade_in duration capping at 256 frames by
  switching fade_level/fade_step to 16.16 fixed-point arithmetic, allowing
  accurate fades of any duration.
- power.rs: Delete callback UID via sceKernelDeleteCallback on drop to prevent
  kernel resource leaks.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix CI: add pre-checkout cleanup to all workflow jobs

The gemini-review, codex-review, agent-review-response, agent-failure-handler
(pr-validation.yml) and create-release (main-ci.yml) jobs were missing
pre-checkout cleanup. When the ci job runs Docker containers that create
root-owned files in outputs/, subsequent jobs fail with EACCES when
actions/checkout tries to clean the workspace.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: address AI review feedback (iteration 2)

Automated fix by Claude in response to Gemini/Codex review.

Iteration: 2/5

Co-Authored-By: AI Review Agent <noreply@anthropic.com>

* fix: address AI review feedback (iteration 3)

- Fix JoinHandle::drop double-free: check thread completion via
  sceKernelWaitThreadEnd before deciding whether to free the closure.
  Previously, dropping an unjoined handle for a thread that already
  finished would double-free the closure (trampoline freed it, then
  drop freed it again).
- Fix audio mixer 1-sample silence gap on loop: remove `continue`
  after resetting position to 0, so the current output frame reads
  from position 0 instead of being skipped.
- Replace unsafe transmute with TryFromPrimitive in system_param:
  language(), date_format(), and time_format() now use safe
  try_from() conversion instead of transmute, preventing UB if
  firmware returns an unexpected enum value.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: eliminate JoinHandle double-free race via shared ThreadPayload

Replace the raw closure pointer with a ThreadPayload struct containing
the closure and an AtomicBool flag. The trampoline sets the flag after
consuming the closure, and Drop checks it after terminating the thread.
This eliminates the race where a thread finishes between the zero-timeout
wait check and sceKernelTerminateDeleteThread, which previously caused
a double-free.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: validate thread name null termination in spawn_inner

Both Gemini and Codex flagged that safe code could pass a non-null-terminated
byte slice to sceKernelCreateThread, causing the kernel to read past the
buffer. Add validation that name ends with \0 before proceeding.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: validate stereo buffer length parity in submit_samples

Reject odd-length buffers in submit_samples to prevent an out-of-bounds
panic when the mixing loop reads stereo pairs (L,R) from a looping
channel that wraps around on a buffer with non-even length.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: AI Agent Bot <ai-agent@localhost>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: AI Review Agent <ai-review-agent@localhost>