`rustdoc +nightly -Zhelp` shows `rustc` unstable-options

$ rustdoc +nightly -Zhelp

Available options:

    -Z                                allow-features=val -- only allow the listed language features to be enabled in code (comma separated)
    -Z                             always-encode-mir=val -- encode MIR of all functions into the crate metadata (default: no)
    -Z                             assert-incr-state=val -- assert that the incremental cache is in given state: either `loaded` or `not-loaded`.
    -Z                     assume-incomplete-release=val -- make cfg(version) treat the current version as incomplete (default: no)
    -Z                                      autodiff=val -- a list of autodiff flags to enable
        Mandatory setting:
        `=Enable`
        Optional extra settings:
        `=PrintTA`
        `=PrintAA`
        `=PrintPerf`
        `=PrintSteps`
        `=PrintModBefore`
        `=PrintModAfter`
        `=PrintModFinal`
        `=PrintPasses`,
        `=NoPostopt`
        `=LooseTypes`
        `=Inline`
        Multiple options can be combined with commas.
    -Z                            binary-dep-depinfo=val -- include artifacts (sysroot, crate dependencies) used during compilation in dep-info (default: no)
    -Z                                   box-noalias=val -- emit noalias metadata for box (default: yes)
    -Z                             branch-protection=val -- set options for branch target identification and pointer authentication on AArch64
    -Z                        build-sdylib-interface=val -- whether the stable interface is being built
    -Z                                 cf-protection=val -- instrument control-flow architecture protection
    -Z                        check-cfg-all-expected=val -- show all expected values in check-cfg diagnostics (default: no)
    -Z                       checksum-hash-algorithm=val -- hash algorithm of source files used to check freshness in cargo (`blake3` or `sha256`)
    -Z                               codegen-backend=val -- the backend to use
    -Z                                   combine-cgu=val -- combine CGUs into a single one
    -Z                               contract-checks=val -- emit runtime checks for contract pre- and post-conditions (default: no)
    -Z                              coverage-options=val -- control details of coverage instrumentation
    -Z                                    crate-attr=val -- inject the given attribute in the crate
    -Z                  cross-crate-inline-threshold=val -- threshold to allow cross crate inlining of functions
    -Z                      debug-info-for-profiling=val -- emit discriminators and other data necessary for AutoFDO
    -Z                  debug-info-type-line-numbers=val -- emit type and line information for additional data types (default: no)
    -Z                         debuginfo-compression=val -- compress debug info sections (none, zlib, zstd, default: none)
    -Z                       deduplicate-diagnostics=val -- deduplicate identical diagnostics (default: yes)
    -Z                            default-visibility=val -- overrides the `default_visibility` setting of the target
    -Z                        dep-info-omit-d-target=val -- in dep-info output, omit targets for tracking dependencies of the dep-info files themselves (default: no)
    -Z                   direct-access-external-data=val -- Direct or use GOT indirect to reference external data symbols
    -Z                              dual-proc-macros=val -- load proc macros for both target and host, but only link to the target (default: no)
    -Z                                dump-dep-graph=val -- dump the dependency graph to $RUST_DEP_GRAPH (default: /tmp/dep_graph.gv) (default: no)
    -Z                                      dump-mir=val -- dump MIR state to file.
        `val` is used to select which passes and functions to dump. For example:
        `all` matches all passes and functions,
        `foo` matches all passes for functions whose name contains 'foo',
        `foo & ConstProp` only the 'ConstProp' pass for function names containing 'foo',
        `foo | bar` all passes for function names containing 'foo' or 'bar'.
    -Z                             dump-mir-dataflow=val -- in addition to `.mir` files, create graphviz `.dot` files with dataflow results (default: no)
    -Z                                  dump-mir-dir=val -- the directory the MIR is dumped into (default: `mir_dump`)
    -Z                  dump-mir-exclude-alloc-bytes=val -- exclude the raw bytes of allocations when dumping MIR (used in tests) (default: no)
    -Z                  dump-mir-exclude-pass-number=val -- exclude the pass number when dumping MIR (used in tests) (default: no)
    -Z                             dump-mir-graphviz=val -- in addition to `.mir` files, create graphviz `.dot` files (default: no)
    -Z                               dump-mono-stats=val -- output statistics about monomorphization collection
    -Z                        dump-mono-stats-format=val -- the format to use for -Z dump-mono-stats (`markdown` (default) or `json`)
    -Z                                 dwarf-version=val -- version of DWARF debug information to emit (default: 2 or 4, depending on platform)
    -Z                                     dylib-lto=val -- enables LTO for dylib crate type
    -Z                     eagerly-emit-delayed-bugs=val -- emit delayed bugs eagerly as errors instead of stashing them and emitting them only if an error has not been emitted
    -Z                                  ehcont-guard=val -- generate Windows EHCont Guard tables
    -Z                                embed-metadata=val -- embed metadata in rlibs and dylibs (default: yes)
    -Z                                  embed-source=val -- embed source text in DWARF debug sections (default: no)
    -Z                              emit-stack-sizes=val -- emit a section containing stack size metadata (default: no)
    -Z                                 emit-thin-lto=val -- emit the bc module with thin LTO info (default: yes)
    -Z                            emscripten-wasm-eh=val -- Use WebAssembly error handling for wasm32-unknown-emscripten
    -Z                     enforce-type-length-limit=val -- enforce the type length limit when monomorphizing instances in codegen
    -Z                   experimental-default-bounds=val -- enable default bounds for experimental group of auto traits
    -Z                     export-executable-symbols=val -- export symbols from executables, as if they were dynamic libraries
    -Z                              external-clangrt=val -- rely on user specified linker commands to find clangrt
    -Z                         extra-const-ub-checks=val -- turns on more checks to detect const UB, which can be slow (default: no)
    -Z                                   fewer-names=val -- reduce memory use by retaining fewer names within compilation artifacts (LLVM-IR) (default: no)
    -Z                                     fixed-x18=val -- make the x18 register reserved on AArch64 (default: no)
    -Z                           flatten-format-args=val -- flatten nested format_args!() and literals into a simplified format_args!() call (default: yes)
    -Z                                     fmt-debug=val -- how detailed `#[derive(Debug)]` should be. `full` prints types recursively, `shallow` prints only type names, `none` prints nothing and disables `{:?}`. (default: `full`)
    -Z                    force-unstable-if-unmarked=val -- force all crates to be `rustc_private` unstable (default: no)
    -Z                               function-return=val -- replace returns with jumps to `__x86_return_thunk` (default: `keep`)
    -Z                             function-sections=val -- whether each function should go in its own section
    -Z                          future-incompat-test=val -- forces all lints to be future incompatible, used for internal testing (default: no)
    -Z                            graphviz-dark-mode=val -- use dark-themed colors in graphviz output (default: no)
    -Z                                 graphviz-font=val -- use the given `fontname` in graphviz output; can be overridden by setting environment variable `RUSTC_GRAPHVIZ_FONT` (default: `Courier, monospace`)
    -Z                              has-thread-local=val -- explicitly enable the `cfg(target_thread_local)` directive
    -Z                      human-readable-cgu-names=val -- generate human-readable, predictable names for codegen units (default: no)
    -Z                              identify-regions=val -- display unnamed regions as `'<id>`, using a non-ident unique id (default: no)
    -Z ignore-directory-in-diagnostics-source-blocks=val -- do not display the source code block in diagnostics for files in the directory
    -Z                      incremental-ignore-spans=val -- ignore spans during ICH computation -- used for testing (default: no)
    -Z                              incremental-info=val -- print high-level information about incremental reuse (or the lack thereof) (default: no)
    -Z                        incremental-verify-ich=val -- verify extended properties for incr. comp. (default: no):
        - hashes of green query instances
        - hash collisions of query keys
        - hash collisions when creating dep-nodes
    -Z                                   inline-llvm=val -- enable LLVM inlining (default: yes)
    -Z                                    inline-mir=val -- enable MIR inlining (default: no)
    -Z                inline-mir-forwarder-threshold=val -- inlining threshold when the caller is a simple forwarding function (default: 30)
    -Z                     inline-mir-hint-threshold=val -- inlining threshold for functions with inline hint (default: 100)
    -Z                     inline-mir-preserve-debug=val -- when MIR inlining, whether to preserve debug info for callee variables (default: preserve for debuginfo != None, otherwise remove)
    -Z                          inline-mir-threshold=val -- a default MIR inlining threshold (default: 50)
    -Z                                   input-stats=val -- print some statistics about AST and HIR (default: no)
    -Z                             instrument-mcount=val -- insert function instrument code for mcount-based tracing (default: no)
    -Z                               instrument-xray=val -- insert function instrument code for XRay-based tracing (default: no)
         Optional extra settings:
         `=always`
         `=never`
         `=ignore-loops`
         `=instruction-threshold=N`
         `=skip-entry`
         `=skip-exit`
         Multiple options can be combined with commas.
    -Z                                   layout-seed=val -- seed layout randomization
    -Z                               link-directives=val -- honor #[link] directives in the compiled crate (default: yes)
    -Z                         link-native-libraries=val -- link native libraries in the linker invocation (default: yes)
    -Z                                     link-only=val -- link the `.rlink` file generated by `-Z no-link` (default: no)
    -Z                               linker-features=val -- a comma-separated list of linker features to enable (+) or disable (-): `lld`
    -Z                                  lint-llvm-ir=val -- lint LLVM IR (default: no)
    -Z                                      lint-mir=val -- lint MIR before and after each transformation
    -Z                              llvm-module-flag=val -- a list of module flags to pass to LLVM (space separated)
    -Z                                  llvm-plugins=val -- a list LLVM plugins to enable (space separated)
    -Z                               llvm-time-trace=val -- generate JSON tracing data file from LLVM data (default: no)
    -Z                               location-detail=val -- what location details should be tracked when using caller_location, either `none`, or a comma separated list of location details, for which valid options are `file`, `line`, and `column` (default: `file,line,column`)
    -Z                                            ls=val -- decode and print various parts of the crate metadata for a library crate (space separated)
    -Z                               macro-backtrace=val -- show macro backtraces (default: no)
    -Z                                   macro-stats=val -- print some statistics about macro expansions (default: no)
    -Z                   maximal-hir-to-mir-coverage=val -- save as much information as possible about the correspondence between MIR and HIR as source scopes (default: no)
    -Z                               merge-functions=val -- control the operation of the MergeFunctions LLVM pass, taking the same values as the target option of the same name
    -Z                                    meta-stats=val -- gather metadata statistics (default: no)
    -Z                                   metrics-dir=val -- the directory metrics emitted by rustc are dumped into (implicitly enables default set of metrics)
    -Z                        min-function-alignment=val -- align all functions to at least this many bytes. Must be a power of 2
    -Z                                mir-emit-retag=val -- emit Retagging MIR statements, interpreted e.g., by miri; implies -Zmir-opt-level=0 (default: no)
    -Z                             mir-enable-passes=val -- use like `-Zmir-enable-passes=+DestinationPropagation,-InstSimplify`. Forces the specified passes to be enabled, overriding all other checks. In particular, this will enable unsound (known-buggy and hence usually disabled) passes without further warning! Passes that are not specified are enabled or disabled by other flags as usual.
    -Z                             mir-include-spans=val -- include extra comments in mir pretty printing, like line numbers and statement indices, details about types, etc. (boolean for all passes, 'nll' to enable in NLL MIR only, default: 'nll')
    -Z                                 mir-opt-level=val -- MIR optimization level (0-4; default: 1 in non optimized builds and 2 in optimized builds)
    -Z                               mir-preserve-ub=val -- keep place mention statements and reads in trivial SwitchInt terminators, which are interpreted e.g., by miri; implies -Zmir-opt-level=0 (default: no)
    -Z                           mir-strip-debuginfo=val -- Whether to remove some of the MIR debug info from methods.  Default: None
    -Z                               move-size-limit=val -- the size at which the `large_assignments` lint starts to be emitted
    -Z                               mutable-noalias=val -- emit noalias metadata for mutable references (default: yes)
    -Z                             namespaced-crates=val -- allow crates to be namespaced by other crates (default: no)
    -Z                                   next-solver=val -- enable and configure the next generation trait solver used by rustc
    -Z                                     nll-facts=val -- dump facts from NLL analysis into side files (default: no)
    -Z                                 nll-facts-dir=val -- the directory the NLL facts are dumped into (default: `nll-facts`)
    -Z                                   no-analysis=val -- parse and expand the source, but run no analysis
    -Z                                    no-codegen=val -- run all passes except codegen; no output
    -Z                    no-generate-arange-section=val -- omit DWARF address ranges that give faster lookups
    -Z                      no-implied-bounds-compat=val -- disable the compatibility version of the `implied_bounds_ty` query
    -Z                                no-jump-tables=val -- disable the jump tables and lookup tables that can be generated from a switch case lowering
    -Z                                 no-leak-check=val -- disable the 'leak check' for subtyping; unsound, but useful for tests
    -Z                                       no-link=val -- compile without linking
    -Z                           no-parallel-backend=val -- run LLVM in non-parallel mode (while keeping codegen-units and ThinLTO)
    -Z                           no-profiler-runtime=val -- prevent automatic injection of the profiler_builtins crate
    -Z                                 no-steal-thir=val -- don't steal the THIR when we're done with it; useful for rustc drivers (default: no)
    -Z                                 no-trait-vptr=val -- disable generation of trait vptr in vtable for upcasting
    -Z                       no-unique-section-names=val -- do not use unique names for text and data sections when -Z function-sections is used
    -Z                                normalize-docs=val -- normalize associated items in rustdoc when generating documentation
    -Z                                on-broken-pipe=val -- behavior of std::io::ErrorKind::BrokenPipe (SIGPIPE)
    -Z                                           oom=val -- panic strategy for out-of-memory handling
    -Z                        osx-rpath-install-name=val -- pass `-install_name @rpath/...` to the macOS linker (default: no)
    -Z                           packed-bundled-libs=val -- change rlib format to store native libraries as archives
    -Z                             panic-abort-tests=val -- support compiling tests with panic=abort (default: no)
    -Z                                 panic-in-drop=val -- panic strategy for panics in drops
    -Z                         parse-crate-root-only=val -- parse the crate root file only; do not parse other files, compile, assemble, or link (default: no)
    -Z                      patchable-function-entry=val -- nop padding at function entry
    -Z                                           plt=val -- whether to use the PLT when calling into shared libraries;
        only has effect for PIC code on systems with ELF binaries
        (default: PLT is disabled if full relro is enabled on x86_64)
    -Z                                      polonius=val -- enable polonius-based borrow-checker (default: no)
    -Z                                  pre-link-arg=val -- a single extra argument to prepend the linker invocation (can be used several times)
    -Z                                 pre-link-args=val -- extra arguments to prepend to the linker invocation (space separated)
    -Z                 precise-enum-drop-elaboration=val -- use a more precise version of drop elaboration for matches on enums (default: yes). This results in better codegen, but has caused miscompilations on some tier 2 platforms. See #77382 and #74551.
    -Z                           print-codegen-stats=val -- print codegen statistics (default: no)
    -Z                             print-llvm-passes=val -- print the LLVM optimization passes being run (default: no)
    -Z                              print-mono-items=val -- print the result of the monomorphization collection pass (default: no)
    -Z                              print-type-sizes=val -- print layout information for each type encountered (default: no)
    -Z                          proc-macro-backtrace=val -- show backtraces for panics during proc-macro execution (default: no)
    -Z                 proc-macro-execution-strategy=val -- how to run proc-macro code (default: same-thread)
    -Z                              profile-closures=val -- profile size of closures
    -Z                            profile-sample-use=val -- use the given `.prof` file for sampled profile-guided optimization (also known as AutoFDO)
    -Z                              profiler-runtime=val -- name of the profiler runtime crate to automatically inject (default: `profiler_builtins`)
    -Z                               query-dep-graph=val -- enable queries of the dependency graph for regression testing (default: no)
    -Z                              randomize-layout=val -- randomize the layout of types (default: no)
    -Z                             reg-struct-return=val -- On x86-32 targets, it overrides the default ABI to return small structs in registers.
        It is UNSOUND to link together crates that use different values for this flag!
    -Z                                       regparm=val -- On x86-32 targets, setting this to N causes the compiler to pass N arguments in registers EAX, EDX, and ECX instead of on the stack for"C", "cdecl", and "stdcall" fn.It is UNSOUND to link together crates that use different values for this flag!
    -Z                         relax-elf-relocations=val -- whether ELF relocations can be relaxed
    -Z                              remap-cwd-prefix=val -- remap paths under the current working directory to this path prefix
    -Z                              remap-path-scope=val -- remap path scope (default: all)
    -Z                                    remark-dir=val -- directory into which to write optimization remarks (if not specified, they will be written to standard error output)
    -Z                                     retpoline=val -- enables retpoline-indirect-branches and retpoline-indirect-calls target features (default: no)
    -Z                      retpoline-external-thunk=val -- enables retpoline-external-thunk, retpoline-indirect-branches and retpoline-indirect-calls target features (default: no)
    -Z                                     sanitizer=val -- use a sanitizer
    -Z           sanitizer-cfi-canonical-jump-tables=val -- enable canonical jump tables (default: yes)
    -Z             sanitizer-cfi-generalize-pointers=val -- enable generalizing pointer types (default: no)
    -Z              sanitizer-cfi-normalize-integers=val -- enable normalizing integer types (default: no)
    -Z                    sanitizer-dataflow-abilist=val -- additional ABI list files that control how shadow parameters are passed (comma separated)
    -Z                          sanitizer-kcfi-arity=val -- enable KCFI arity indicator (default: no)
    -Z                sanitizer-memory-track-origins=val -- enable origins tracking in MemorySanitizer
    -Z                             sanitizer-recover=val -- enable recovery for selected sanitizers
    -Z                        saturating-float-casts=val -- make float->int casts UB-free: numbers outside the integer type's range are clipped to the max/min integer respectively, and NaN is mapped to 0 (default: yes)
    -Z                                  self-profile=val -- run the self profiler and output the raw event data
    -Z                          self-profile-counter=val -- counter used by the self profiler (default: `wall-time`), one of:
        `wall-time` (monotonic clock, i.e. `std::time::Instant`)
        `instructions:u` (retired instructions, userspace-only)
        `instructions-minus-irqs:u` (subtracting hardware interrupt counts for extra accuracy)
    -Z                           self-profile-events=val -- specify the events recorded by the self profiler;
        for example: `-Z self-profile-events=default,query-keys`
        all options: none, all, default, generic-activity, query-provider, query-cache-hit
                     query-blocked, incr-cache-load, incr-result-hashing, query-keys, function-args, args, llvm, artifact-sizes
    -Z                                share-generics=val -- make the current crate share its generic instantiations
    -Z                                shell-argfiles=val -- allow argument files to be specified with POSIX "shell-style" argument quoting
    -Z               simulate-remapped-rust-src-base=val -- simulate the effect of remap-debuginfo = true at bootstrapping by remapping path to rust's source base directory. only meant for testing purposes
    -Z                          small-data-threshold=val -- Set the threshold for objects to be stored in a "small data" section
    -Z                                    span-debug=val -- forward proc_macro::Span's `Debug` impl to `Span`
    -Z                             span-free-formats=val -- exclude spans when debug-printing compiler state (default: no)
    -Z                          split-dwarf-inlining=val -- provide minimal debug info in the object/executable to facilitate online symbolication/stack traces in the absence of .dwo/.dwp files when using Split DWARF
    -Z                              split-dwarf-kind=val -- split dwarf variant (only if -Csplit-debuginfo is enabled and on relevant platform)
        (default: `split`)

        `split`: sections which do not require relocation are written into a DWARF object (`.dwo`)
                 file which is ignored by the linker
        `single`: sections which do not require relocation are written into object file but ignored
                  by the linker
    -Z                                split-lto-unit=val -- enable LTO unit splitting (default: no)
    -Z                            src-hash-algorithm=val -- hash algorithm of source files in debug info (`md5`, `sha1`, or `sha256`)
    -Z                               stack-protector=val -- control stack smash protection strategy (`rustc --print stack-protector-strategies` for details)
    -Z                   staticlib-allow-rdylib-deps=val -- allow staticlibs to have rust dylib dependencies
    -Z                      staticlib-prefer-dynamic=val -- prefer dynamic linking to static linking for staticlibs (default: no)
    -Z                            strict-init-checks=val -- control if mem::uninitialized and mem::zeroed panic on more UB
    -Z                                         teach=val -- show extended diagnostic help (default: no)
    -Z                                     temps-dir=val -- the directory the intermediate files are written to
    -Z                                 terminal-urls=val -- use the OSC 8 hyperlink terminal specification to print hyperlinks in the compiler output
    -Z                                       thinlto=val -- enable ThinLTO when possible
    -Z                                       threads=val -- use a thread pool with N threads
    -Z                              time-llvm-passes=val -- measure time of each LLVM pass (default: no)
    -Z                                   time-passes=val -- measure time of each rustc pass (default: no)
    -Z                            time-passes-format=val -- the format to use for -Z time-passes (`text` (default) or `json`)
    -Z                         tiny-const-eval-limit=val -- sets a tiny, non-configurable limit for const eval; useful for compiler tests
    -Z                                     tls-model=val -- choose the TLS model to use (`rustc --print tls-models` for details)
    -Z                                  trace-macros=val -- for every macro invocation, print its name and arguments (default: no)
    -Z                             track-diagnostics=val -- tracks where in rustc a diagnostic was emitted
    -Z                      translate-additional-ftl=val -- additional fluent translation to preferentially use (for testing translation)
    -Z              translate-directionality-markers=val -- emit directionality isolation markers in translated diagnostics
    -Z                                translate-lang=val -- language identifier for diagnostic output
    -Z         translate-remapped-path-to-local-path=val -- translate remapped paths into local paths when possible (default: yes)
    -Z                              trap-unreachable=val -- generate trap instructions for unreachable intrinsics (default: use target setting, usually yes)
    -Z                              treat-err-as-bug=val -- treat the `val`th error that occurs as bug (default if not specified: 0 - don't treat errors as bugs. default if specified without a value: 1 - treat the first error as bug)
    -Z                         trim-diagnostic-paths=val -- in diagnostics, use heuristics to shorten paths referring to items
    -Z                                      tune-cpu=val -- select processor to schedule for (`rustc --print target-cpus` for details)
    -Z                          typing-mode-borrowck=val -- enable `TypingMode::Borrowck`, changing the way opaque types are handled during MIR borrowck
    -Z                                     ub-checks=val -- emit runtime checks for Undefined Behavior (default: -Cdebug-assertions)
    -Z                                    ui-testing=val -- emit compiler diagnostics in a form suitable for UI testing (default: no)
    -Z                  uninit-const-chunk-threshold=val -- allow generating const initializers with mixed init/uninit chunks, and set the maximum number of chunks for which this is allowed (default: 16)
    -Z                unleash-the-miri-inside-of-you=val -- take the brakes off const evaluation. NOTE: this is unsound (default: no)
    -Z                                      unpretty=val -- present the input source, unstable (and less-pretty) variants;
        `normal`, `identified`,
        `expanded`, `expanded,identified`,
        `expanded,hygiene` (with internal representations),
        `ast-tree` (raw AST before expansion),
        `ast-tree,expanded` (raw AST after expansion),
        `hir` (the HIR), `hir,identified`,
        `hir,typed` (HIR with types for each node),
        `hir-tree` (dump the raw HIR),
        `thir-tree`, `thir-flat`,
        `mir` (the MIR), or `mir-cfg` (graphviz formatted MIR)
    -Z                              unsound-mir-opts=val -- enable unsound and buggy MIR optimizations (default: no)
    -Z                              unstable-options=val -- adds unstable command line options to rustc interface (default: no)
    -Z                             use-ctors-section=val -- use legacy .ctors section for initializers rather than .init_array
    -Z                               use-sync-unwind=val -- Generate sync unwind tables instead of async unwind tables (default: no)
    -Z                                  validate-mir=val -- validate MIR after each transformation
    -Z                                   verbose-asm=val -- add descriptive comments from LLVM to the assembly (may change behavior) (default: no)
    -Z                             verbose-internals=val -- in general, enable more debug printouts (default: no)
    -Z                                verify-llvm-ir=val -- verify LLVM IR (default: no)
    -Z                  virtual-function-elimination=val -- enables dead virtual function elimination optimization. Requires `-Clto[=[fat,yes]]`
    -Z                               wasi-exec-model=val -- whether to build a wasi command or reactor
    -Z                      write-long-types-to-disk=val -- whether long type names should be written to files instead of being printed in errors