-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-drop-tracking-cfg=val -- dump drop-tracking control-flow graph as a `.dot` file (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-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 (and with `-Z instrument-coverage`, also create a `.dot` file for the MIR-derived coverage graph) (default: no)
-Z dump-mir-spanview=val -- in addition to `.mir` files, create `.html` files to view spans for all `statement`s (including terminators), only `terminator` spans, or computed `block` spans (one span encompassing a block's terminator and all statements). If `-Z instrument-coverage` is also enabled, create an additional `.html` file showing the computed coverage spans.
-Z fewer-names=val -- reduce memory use by retaining fewer names within compilation artifacts (LLVM-IR) (default: no)
-Z force-unstable-if-unmarked=val -- force all crates to be `rustc_private` unstable (default: no)
-Z fuel=val -- set the optimization fuel quota for a crate
-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 gcc-ld=val -- implementation of ld used by cc
-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 hir-stats=val -- print some statistics about AST and HIR (default: no)
-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 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-relative-spans=val -- hash spans relative to their parent item for incr. comp. (default: no)
-Z incremental-verify-ich=val -- verify incr. comp. hashes of green query instances (default: no)
-Z input-stats=val -- gather statistics about the input (default: no)
-Z instrument-coverage=val -- instrument the generated code to support LLVM source-based code coverage reports (note, the compiler build config must include `profiler = true`); implies `-C symbol-mangling-version=v0`. Optional values are:
`=all` (implicit value)
`=except-unused-generics`
`=except-unused-functions`
`=off` (default)
-Z instrument-mcount=val -- insert function instrument code for mcount-based tracing (default: no)
-Z keep-hygiene-data=val -- keep hygiene data after analysis (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 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=+DestProp,-InstCombine`. Forces the specified passes to be enabled, overriding all other checks. Passes that are not specified are enabled or disabled by other flags as usual.
-Z mir-opt-level=val -- MIR optimization level (0-4; default: 1 in non optimized builds and 2 in optimized builds)
-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-fuel=val -- make rustc print the total optimization fuel used by a crate
-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
-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 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 save-analysis=val -- write syntax and type analysis (in JSON format) information, in addition to normal output (default: no)
-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`)
-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 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 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)
