1 -Z allow-features=val -- only allow the listed language features to be enabled in code (space separated)
2 -Z always-encode-mir=val -- encode MIR of all functions into the crate metadata (default: no)
3 -Z assume-incomplete-release=val -- make cfg(version) treat the current version as incomplete (default: no)
4 -Z asm-comments=val -- generate comments into the assembly (may change behavior) (default: no)
5 -Z assert-incr-state=val -- assert that the incremental cache is in given state: either `loaded` or `not-loaded`.
6 -Z binary-dep-depinfo=val -- include artifacts (sysroot, crate dependencies) used during compilation in dep-info (default: no)
7 -Z box-noalias=val -- emit noalias metadata for box (default: yes)
8 -Z branch-protection=val -- set options for branch target identification and pointer authentication on AArch64
9 -Z cf-protection=val -- instrument control-flow architecture protection
10 -Z cgu-partitioning-strategy=val -- the codegen unit partitioning strategy to use
11 -Z chalk=val -- enable the experimental Chalk-based trait solving engine
12 -Z codegen-backend=val -- the backend to use
13 -Z combine-cgu=val -- combine CGUs into a single one
14 -Z crate-attr=val -- inject the given attribute in the crate
15 -Z debug-info-for-profiling=val -- emit discriminators and other data necessary for AutoFDO
16 -Z debug-macros=val -- emit line numbers debug info inside macros (default: no)
17 -Z deduplicate-diagnostics=val -- deduplicate identical diagnostics (default: yes)
18 -Z dep-info-omit-d-target=val -- in dep-info output, omit targets for tracking dependencies of the dep-info files themselves (default: no)
19 -Z dep-tasks=val -- print tasks that execute and the color their dep node gets (requires debug build) (default: no)
20 -Z dlltool=val -- import library generation tool (windows-gnu only)
21 -Z dont-buffer-diagnostics=val -- emit diagnostics rather than buffering (breaks NLL error downgrading, sorting) (default: no)
22 -Z drop-tracking=val -- enables drop tracking in generators (default: no)
23 -Z dual-proc-macros=val -- load proc macros for both target and host, but only link to the target (default: no)
24 -Z dump-dep-graph=val -- dump the dependency graph to $RUST_DEP_GRAPH (default: /tmp/dep_graph.gv) (default: no)
25 -Z dump-drop-tracking-cfg=val -- dump drop-tracking control-flow graph as a `.dot` file (default: no)
26 -Z dump-mir=val -- dump MIR state to file.
27 `val` is used to select which passes and functions to dump. For example:
28 `all` matches all passes and functions,
29 `foo` matches all passes for functions whose name contains 'foo',
30 `foo & ConstProp` only the 'ConstProp' pass for function names containing 'foo',
31 `foo | bar` all passes for function names containing 'foo' or 'bar'.
32 -Z dump-mir-dataflow=val -- in addition to `.mir` files, create graphviz `.dot` files with dataflow results (default: no)
33 -Z dump-mir-dir=val -- the directory the MIR is dumped into (default: `mir_dump`)
34 -Z dump-mir-exclude-pass-number=val -- exclude the pass number when dumping MIR (used in tests) (default: no)
35 -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)
36 -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.
37 -Z dwarf-version=val -- version of DWARF debug information to emit (default: 2 or 4, depending on platform)
38 -Z emit-stack-sizes=val -- emit a section containing stack size metadata (default: no)
39 -Z emit-thin-lto=val -- emit the bc module with thin LTO info (default: yes)
40 -Z export-executable-symbols=val -- export symbols from executables, as if they were dynamic libraries
41 -Z extra-const-ub-checks=val -- turns on more checks to detect const UB, which can be slow (default: no)
42 -Z fewer-names=val -- reduce memory use by retaining fewer names within compilation artifacts (LLVM-IR) (default: no)
43 -Z force-unstable-if-unmarked=val -- force all crates to be `rustc_private` unstable (default: no)
44 -Z fuel=val -- set the optimization fuel quota for a crate
45 -Z function-sections=val -- whether each function should go in its own section
46 -Z future-incompat-test=val -- forces all lints to be future incompatible, used for internal testing (default: no)
47 -Z gcc-ld=val -- implementation of ld used by cc
48 -Z graphviz-dark-mode=val -- use dark-themed colors in graphviz output (default: no)
49 -Z graphviz-font=val -- use the given `fontname` in graphviz output; can be overridden by setting environment variable `RUSTC_GRAPHVIZ_FONT` (default: `Courier, monospace`)
50 -Z hir-stats=val -- print some statistics about AST and HIR (default: no)
51 -Z human-readable-cgu-names=val -- generate human-readable, predictable names for codegen units (default: no)
52 -Z identify-regions=val -- display unnamed regions as `'<id>`, using a non-ident unique id (default: no)
53 -Z incremental-ignore-spans=val -- ignore spans during ICH computation -- used for testing (default: no)
54 -Z incremental-info=val -- print high-level information about incremental reuse (or the lack thereof) (default: no)
55 -Z incremental-relative-spans=val -- hash spans relative to their parent item for incr. comp. (default: no)
56 -Z incremental-verify-ich=val -- verify incr. comp. hashes of green query instances (default: no)
57 -Z inline-mir=val -- enable MIR inlining (default: no)
58 -Z inline-mir-threshold=val -- a default MIR inlining threshold (default: 50)
59 -Z inline-mir-hint-threshold=val -- inlining threshold for functions with inline hint (default: 100)
60 -Z inline-in-all-cgus=val -- control whether `#[inline]` functions are in all CGUs
61 -Z input-stats=val -- gather statistics about the input (default: no)
62 -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:
63 `=all` (implicit value)
64 `=except-unused-generics`
65 `=except-unused-functions`
67 -Z instrument-mcount=val -- insert function instrument code for mcount-based tracing (default: no)
68 -Z keep-hygiene-data=val -- keep hygiene data after analysis (default: no)
69 -Z link-native-libraries=val -- link native libraries in the linker invocation (default: yes)
70 -Z link-only=val -- link the `.rlink` file generated by `-Z no-link` (default: no)
71 -Z llvm-plugins=val -- a list LLVM plugins to enable (space separated)
72 -Z llvm-time-trace=val -- generate JSON tracing data file from LLVM data (default: no)
73 -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`)
74 -Z ls=val -- list the symbols defined by a library crate (default: no)
75 -Z macro-backtrace=val -- show macro backtraces (default: no)
76 -Z merge-functions=val -- control the operation of the MergeFunctions LLVM pass, taking the same values as the target option of the same name
77 -Z meta-stats=val -- gather metadata statistics (default: no)
78 -Z mir-emit-retag=val -- emit Retagging MIR statements, interpreted e.g., by miri; implies -Zmir-opt-level=0 (default: no)
79 -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.
80 -Z mir-pretty-relative-line-numbers=val -- use line numbers relative to the function in mir pretty printing
81 -Z mir-opt-level=val -- MIR optimization level (0-4; default: 1 in non optimized builds and 2 in optimized builds)
82 -Z move-size-limit=val -- the size at which the `large_assignments` lint starts to be emitted
83 -Z mutable-noalias=val -- emit noalias metadata for mutable references (default: yes)
84 -Z new-llvm-pass-manager=val -- use new LLVM pass manager (default: no)
85 -Z nll-facts=val -- dump facts from NLL analysis into side files (default: no)
86 -Z nll-facts-dir=val -- the directory the NLL facts are dumped into (default: `nll-facts`)
87 -Z no-analysis=val -- parse and expand the source, but run no analysis
88 -Z no-codegen=val -- run all passes except codegen; no output
89 -Z no-generate-arange-section=val -- omit DWARF address ranges that give faster lookups
90 -Z no-interleave-lints=val -- execute lints separately; allows benchmarking individual lints
91 -Z no-leak-check=val -- disable the 'leak check' for subtyping; unsound, but useful for tests
92 -Z no-link=val -- compile without linking
93 -Z no-parallel-llvm=val -- run LLVM in non-parallel mode (while keeping codegen-units and ThinLTO)
94 -Z no-unique-section-names=val -- do not use unique names for text and data sections when -Z function-sections is used
95 -Z no-profiler-runtime=val -- prevent automatic injection of the profiler_builtins crate
96 -Z normalize-docs=val -- normalize associated items in rustdoc when generating documentation
97 -Z oom=val -- panic strategy for out-of-memory handling
98 -Z osx-rpath-install-name=val -- pass `-install_name @rpath/...` to the macOS linker (default: no)
99 -Z diagnostic-width=val -- set the current output width for diagnostic truncation
100 -Z panic-abort-tests=val -- support compiling tests with panic=abort (default: no)
101 -Z panic-in-drop=val -- panic strategy for panics in drops
102 -Z parse-only=val -- parse only; do not compile, assemble, or link (default: no)
103 -Z perf-stats=val -- print some performance-related statistics (default: no)
104 -Z pick-stable-methods-before-any-unstable=val -- try to pick stable methods first before picking any unstable methods (default: yes)
105 -Z plt=val -- whether to use the PLT when calling into shared libraries;
106 only has effect for PIC code on systems with ELF binaries
107 (default: PLT is disabled if full relro is enabled)
108 -Z polonius=val -- enable polonius-based borrow-checker (default: no)
109 -Z polymorphize=val -- perform polymorphization analysis
110 -Z pre-link-arg=val -- a single extra argument to prepend the linker invocation (can be used several times)
111 -Z pre-link-args=val -- extra arguments to prepend to the linker invocation (space separated)
112 -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.
113 -Z print-fuel=val -- make rustc print the total optimization fuel used by a crate
114 -Z print-llvm-passes=val -- print the LLVM optimization passes being run (default: no)
115 -Z print-mono-items=val -- print the result of the monomorphization collection pass
116 -Z print-type-sizes=val -- print layout information for each type encountered (default: no)
117 -Z proc-macro-backtrace=val -- show backtraces for panics during proc-macro execution (default: no)
118 -Z proc-macro-execution-strategy=val -- how to run proc-macro code (default: same-thread)
119 -Z profile=val -- insert profiling code (default: no)
120 -Z profile-closures=val -- profile size of closures
121 -Z profile-emit=val -- file path to emit profiling data at runtime when using 'profile' (default based on relative source path)
122 -Z profiler-runtime=val -- name of the profiler runtime crate to automatically inject (default: `profiler_builtins`)
123 -Z profile-sample-use=val -- use the given `.prof` file for sampled profile-guided optimization (also known as AutoFDO)
124 -Z query-dep-graph=val -- enable queries of the dependency graph for regression testing (default: no)
125 -Z randomize-layout=val -- randomize the layout of types (default: no)
126 -Z layout-seed=val -- seed layout randomization
127 -Z relax-elf-relocations=val -- whether ELF relocations can be relaxed
128 -Z relro-level=val -- choose which RELRO level to use
129 -Z remap-cwd-prefix=val -- remap paths under the current working directory to this path prefix
130 -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
131 -Z report-delayed-bugs=val -- immediately print bugs registered with `delay_span_bug` (default: no)
132 -Z sanitizer=val -- use a sanitizer
133 -Z sanitizer-memory-track-origins=val -- enable origins tracking in MemorySanitizer
134 -Z sanitizer-recover=val -- enable recovery for selected sanitizers
135 -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)
136 -Z save-analysis=val -- write syntax and type analysis (in JSON format) information, in addition to normal output (default: no)
137 -Z self-profile=val -- run the self profiler and output the raw event data
138 -Z self-profile-events=val -- specify the events recorded by the self profiler;
139 for example: `-Z self-profile-events=default,query-keys`
140 all options: none, all, default, generic-activity, query-provider, query-cache-hit
141 query-blocked, incr-cache-load, incr-result-hashing, query-keys, function-args, args, llvm, artifact-sizes
142 -Z self-profile-counter=val -- counter used by the self profiler (default: `wall-time`), one of:
143 `wall-time` (monotonic clock, i.e. `std::time::Instant`)
144 `instructions:u` (retired instructions, userspace-only)
145 `instructions-minus-irqs:u` (subtracting hardware interrupt counts for extra accuracy)
146 -Z share-generics=val -- make the current crate share its generic instantiations
147 -Z show-span=val -- show spans for compiler debugging (expr|pat|ty)
148 -Z span-debug=val -- forward proc_macro::Span's `Debug` impl to `Span`
149 -Z span-free-formats=val -- exclude spans when debug-printing compiler state (default: no)
150 -Z src-hash-algorithm=val -- hash algorithm of source files in debug info (`md5`, `sha1`, or `sha256`)
151 -Z stack-protector=val -- control stack smash protection strategy (`rustc --print stack-protector-strategies` for details)
152 -Z strict-init-checks=val -- control if mem::uninitialized and mem::zeroed panic on more UB
153 -Z strip=val -- tell the linker which information to strip (`none` (default), `debuginfo` or `symbols`)
154 -Z split-dwarf-kind=val -- split dwarf variant (only if -Csplit-debuginfo is enabled and on relevant platform)
157 `split`: sections which do not require relocation are written into a DWARF object (`.dwo`)
158 file which is ignored by the linker
159 `single`: sections which do not require relocation are written into object file but ignored
161 -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
162 -Z symbol-mangling-version=val -- which mangling version to use for symbol names ('legacy' (default) or 'v0')
163 -Z teach=val -- show extended diagnostic help (default: no)
164 -Z temps-dir=val -- the directory the intermediate files are written to
165 -Z translate-lang=val -- language identifier for diagnostic output
166 -Z translate-additional-ftl=val -- additional fluent translation to preferentially use (for testing translation)
167 -Z translate-directionality-markers=val -- emit directionality isolation markers in translated diagnostics
168 -Z tune-cpu=val -- select processor to schedule for (`rustc --print target-cpus` for details)
169 -Z thinlto=val -- enable ThinLTO when possible
170 -Z thir-unsafeck=val -- use the THIR unsafety checker (default: no)
171 -Z threads=val -- use a thread pool with N threads
172 -Z time=val -- measure time of rustc processes (default: no)
173 -Z time-llvm-passes=val -- measure time of each LLVM pass (default: no)
174 -Z time-passes=val -- measure time of each rustc pass (default: no)
175 -Z tls-model=val -- choose the TLS model to use (`rustc --print tls-models` for details)
176 -Z trace-macros=val -- for every macro invocation, print its name and arguments (default: no)
177 -Z translate-remapped-path-to-local-path=val -- translate remapped paths into local paths when possible (default: yes)
178 -Z trap-unreachable=val -- generate trap instructions for unreachable intrinsics (default: use target setting, usually yes)
179 -Z treat-err-as-bug=val -- treat error number `val` that occurs as bug
180 -Z trim-diagnostic-paths=val -- in diagnostics, use heuristics to shorten paths referring to items
181 -Z ui-testing=val -- emit compiler diagnostics in a form suitable for UI testing (default: no)
182 -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)
183 -Z unleash-the-miri-inside-of-you=val -- take the brakes off const evaluation. NOTE: this is unsound (default: no)
184 -Z unpretty=val -- present the input source, unstable (and less-pretty) variants;
185 `normal`, `identified`,
186 `expanded`, `expanded,identified`,
187 `expanded,hygiene` (with internal representations),
188 `ast-tree` (raw AST before expansion),
189 `ast-tree,expanded` (raw AST after expansion),
190 `hir` (the HIR), `hir,identified`,
191 `hir,typed` (HIR with types for each node),
192 `hir-tree` (dump the raw HIR),
193 `mir` (the MIR), or `mir-cfg` (graphviz formatted MIR)
194 -Z unsound-mir-opts=val -- enable unsound and buggy MIR optimizations (default: no)
195 -Z unstable-options=val -- adds unstable command line options to rustc interface (default: no)
196 -Z use-ctors-section=val -- use legacy .ctors section for initializers rather than .init_array
197 -Z validate-mir=val -- validate MIR after each transformation
198 -Z verbose=val -- in general, enable more debug printouts (default: no)
199 -Z verify-llvm-ir=val -- verify LLVM IR (default: no)
200 -Z virtual-function-elimination=val -- enables dead virtual function elimination optimization. Requires `-Clto[=[fat,yes]]`
201 -Z wasi-exec-model=val -- whether to build a wasi command or reactor