xref: /wasmtime-44.0.1/crates/cli-flags/src/lib.rs (revision 10deb9b7)
1 //! Contains the common Wasmtime command line interface (CLI) flags.
2 
3 #![deny(trivial_numeric_casts, unused_extern_crates, unstable_features)]
4 #![warn(unused_import_braces)]
5 #![cfg_attr(feature = "clippy", plugin(clippy(conf_file = "../../clippy.toml")))]
6 #![cfg_attr(feature = "cargo-clippy", allow(clippy::new_without_default))]
7 #![cfg_attr(
8     feature = "cargo-clippy",
9     warn(
10         clippy::float_arithmetic,
11         clippy::mut_mut,
12         clippy::nonminimal_bool,
13         clippy::map_unwrap_or,
14         clippy::unicode_not_nfc,
15         clippy::use_self
16     )
17 )]
18 
19 use anyhow::{bail, Context, Result};
20 use clap::Parser;
21 use std::collections::HashMap;
22 use std::path::PathBuf;
23 use wasmtime::{Config, ProfilingStrategy};
24 #[cfg(feature = "pooling-allocator")]
25 use wasmtime::{InstanceLimits, PoolingAllocationStrategy};
26 
27 pub const SUPPORTED_WASM_FEATURES: &[(&str, &str)] = &[
28     ("all", "enables all supported WebAssembly features"),
29     (
30         "bulk-memory",
31         "enables support for bulk memory instructions",
32     ),
33     (
34         "multi-memory",
35         "enables support for the multi-memory proposal",
36     ),
37     ("multi-value", "enables support for multi-value functions"),
38     ("reference-types", "enables support for reference types"),
39     ("simd", "enables support for proposed SIMD instructions"),
40     ("threads", "enables support for WebAssembly threads"),
41     ("memory64", "enables support for 64-bit memories"),
42     #[cfg(feature = "component-model")]
43     ("component-model", "enables support for the component model"),
44 ];
45 
46 pub const SUPPORTED_WASI_MODULES: &[(&str, &str)] = &[
47     (
48         "default",
49         "enables all stable WASI modules (no experimental modules)",
50     ),
51     (
52         "wasi-common",
53         "enables support for the WASI common APIs, see https://github.com/WebAssembly/WASI",
54     ),
55     (
56         "experimental-wasi-nn",
57         "enables support for the WASI neural network API (experimental), see https://github.com/WebAssembly/wasi-nn",
58     ),
59     (
60         "experimental-wasi-crypto",
61         "enables support for the WASI cryptography APIs (experimental), see https://github.com/WebAssembly/wasi-crypto",
62     ),
63 ];
64 
65 fn pick_profiling_strategy(jitdump: bool, vtune: bool) -> Result<ProfilingStrategy> {
66     Ok(match (jitdump, vtune) {
67         (true, false) => ProfilingStrategy::JitDump,
68         (false, true) => ProfilingStrategy::VTune,
69         (true, true) => {
70             println!("Can't enable --jitdump and --vtune at the same time. Profiling not enabled.");
71             ProfilingStrategy::None
72         }
73         _ => ProfilingStrategy::None,
74     })
75 }
76 
77 fn init_file_per_thread_logger(prefix: &'static str) {
78     file_per_thread_logger::initialize(prefix);
79 
80     // Extending behavior of default spawner:
81     // https://docs.rs/rayon/1.1.0/rayon/struct.ThreadPoolBuilder.html#method.spawn_handler
82     // Source code says DefaultSpawner is implementation detail and
83     // shouldn't be used directly.
84     rayon::ThreadPoolBuilder::new()
85         .spawn_handler(move |thread| {
86             let mut b = std::thread::Builder::new();
87             if let Some(name) = thread.name() {
88                 b = b.name(name.to_owned());
89             }
90             if let Some(stack_size) = thread.stack_size() {
91                 b = b.stack_size(stack_size);
92             }
93             b.spawn(move || {
94                 file_per_thread_logger::initialize(prefix);
95                 thread.run()
96             })?;
97             Ok(())
98         })
99         .build_global()
100         .unwrap();
101 }
102 
103 /// Common options for commands that translate WebAssembly modules
104 #[derive(Parser)]
105 #[cfg_attr(test, derive(Debug, PartialEq))]
106 pub struct CommonOptions {
107     /// Use specified configuration file
108     #[clap(long, parse(from_os_str), value_name = "CONFIG_PATH")]
109     pub config: Option<PathBuf>,
110 
111     /// Disable logging.
112     #[clap(long, conflicts_with = "log-to-files")]
113     pub disable_logging: bool,
114 
115     /// Log to per-thread log files instead of stderr.
116     #[clap(long)]
117     pub log_to_files: bool,
118 
119     /// Generate debug information
120     #[clap(short = 'g')]
121     pub debug_info: bool,
122 
123     /// Disable cache system
124     #[clap(long)]
125     pub disable_cache: bool,
126 
127     /// Disable parallel compilation
128     #[clap(long)]
129     pub disable_parallel_compilation: bool,
130 
131     /// Enables or disables WebAssembly features
132     #[clap(long, value_name = "FEATURE,FEATURE,...", parse(try_from_str = parse_wasm_features))]
133     pub wasm_features: Option<WasmFeatures>,
134 
135     /// Enables or disables WASI modules
136     #[clap(long, value_name = "MODULE,MODULE,...", parse(try_from_str = parse_wasi_modules))]
137     pub wasi_modules: Option<WasiModules>,
138 
139     /// Generate jitdump file (supported on --features=profiling build)
140     #[clap(long, conflicts_with = "vtune")]
141     pub jitdump: bool,
142 
143     /// Generate vtune (supported on --features=vtune build)
144     #[clap(long, conflicts_with = "jitdump")]
145     pub vtune: bool,
146 
147     /// Run optimization passes on translated functions, on by default
148     #[clap(short = 'O', long)]
149     pub optimize: bool,
150 
151     /// Optimization level for generated functions
152     /// Supported levels: 0 (none), 1, 2 (most), or s (size); default is "most"
153     #[clap(
154         long,
155         value_name = "LEVEL",
156         parse(try_from_str = parse_opt_level),
157         verbatim_doc_comment,
158     )]
159     pub opt_level: Option<wasmtime::OptLevel>,
160 
161     /// Set a Cranelift setting to a given value.
162     /// Use `wasmtime settings` to list Cranelift settings for a target.
163     #[clap(long = "cranelift-set", value_name = "NAME=VALUE", number_of_values = 1, verbatim_doc_comment, parse(try_from_str = parse_cranelift_flag))]
164     pub cranelift_set: Vec<(String, String)>,
165 
166     /// Enable a Cranelift boolean setting or preset.
167     /// Use `wasmtime settings` to list Cranelift settings for a target.
168     #[clap(
169         long,
170         value_name = "SETTING",
171         number_of_values = 1,
172         verbatim_doc_comment
173     )]
174     pub cranelift_enable: Vec<String>,
175 
176     /// Maximum size in bytes of wasm memory before it becomes dynamically
177     /// relocatable instead of up-front-reserved.
178     #[clap(long, value_name = "MAXIMUM")]
179     pub static_memory_maximum_size: Option<u64>,
180 
181     /// Force using a "static" style for all wasm memories.
182     #[clap(long)]
183     pub static_memory_forced: bool,
184 
185     /// Byte size of the guard region after static memories are allocated.
186     #[clap(long, value_name = "SIZE")]
187     pub static_memory_guard_size: Option<u64>,
188 
189     /// Byte size of the guard region after dynamic memories are allocated.
190     #[clap(long, value_name = "SIZE")]
191     pub dynamic_memory_guard_size: Option<u64>,
192 
193     /// Enable Cranelift's internal debug verifier (expensive)
194     #[clap(long)]
195     pub enable_cranelift_debug_verifier: bool,
196 
197     /// Enable Cranelift's internal NaN canonicalization
198     #[clap(long)]
199     pub enable_cranelift_nan_canonicalization: bool,
200 
201     /// Enable execution fuel with N units fuel, where execution will trap after
202     /// running out of fuel.
203     ///
204     /// Most WebAssembly instructions consume 1 unit of fuel. Some instructions,
205     /// such as `nop`, `drop`, `block`, and `loop`, consume 0 units, as any
206     /// execution cost associated with them involves other instructions which do
207     /// consume fuel.
208     #[clap(long, value_name = "N")]
209     pub fuel: Option<u64>,
210 
211     /// Executing wasm code will yield when a global epoch counter
212     /// changes, allowing for async operation without blocking the
213     /// executor.
214     #[clap(long)]
215     pub epoch_interruption: bool,
216 
217     /// Disables the on-by-default address map from native code to wasm code.
218     #[clap(long)]
219     pub disable_address_map: bool,
220 
221     /// Disables the default of attempting to initialize linear memory via a
222     /// copy-on-write mapping.
223     #[cfg(feature = "memory-init-cow")]
224     #[clap(long)]
225     pub disable_memory_init_cow: bool,
226 
227     /// Enables the pooling allocator, in place of the on-demand
228     /// allocator.
229     #[cfg(feature = "pooling-allocator")]
230     #[clap(long)]
231     pub pooling_allocator: bool,
232 }
233 
234 impl CommonOptions {
235     pub fn parse_from_str(s: &str) -> Result<Self> {
236         let parts = s.split(" ").filter(|s| !s.is_empty());
237         // The first argument is the name of the executable, which we don't use
238         // here, but have to provide because `clap` skips over it, and otherwise
239         // our first CLI flag will be ignored.
240         let parts = Some("wasmtime").into_iter().chain(parts);
241         let options =
242             Self::try_parse_from(parts).context("unable to parse options from passed flags")?;
243         Ok(options)
244     }
245 
246     pub fn init_logging(&self) {
247         if self.disable_logging {
248             return;
249         }
250         if self.log_to_files {
251             let prefix = "wasmtime.dbg.";
252             init_file_per_thread_logger(prefix);
253         } else {
254             pretty_env_logger::init();
255         }
256     }
257 
258     pub fn config(&self, target: Option<&str>) -> Result<Config> {
259         let mut config = Config::new();
260 
261         // Set the target before setting any cranelift options, since the
262         // target will reset any target-specific options.
263         if let Some(target) = target {
264             config.target(target)?;
265         }
266 
267         config
268             .cranelift_debug_verifier(self.enable_cranelift_debug_verifier)
269             .debug_info(self.debug_info)
270             .cranelift_opt_level(self.opt_level())
271             .profiler(pick_profiling_strategy(self.jitdump, self.vtune)?)
272             .cranelift_nan_canonicalization(self.enable_cranelift_nan_canonicalization);
273 
274         self.enable_wasm_features(&mut config);
275 
276         for name in &self.cranelift_enable {
277             unsafe {
278                 config.cranelift_flag_enable(name);
279             }
280         }
281 
282         for (name, value) in &self.cranelift_set {
283             unsafe {
284                 config.cranelift_flag_set(name, value);
285             }
286         }
287 
288         if !self.disable_cache {
289             match &self.config {
290                 Some(path) => {
291                     config.cache_config_load(path)?;
292                 }
293                 None => {
294                     config.cache_config_load_default()?;
295                 }
296             }
297         }
298 
299         if self.disable_parallel_compilation {
300             config.parallel_compilation(false);
301         }
302 
303         if let Some(max) = self.static_memory_maximum_size {
304             config.static_memory_maximum_size(max);
305         }
306 
307         config.static_memory_forced(self.static_memory_forced);
308 
309         if let Some(size) = self.static_memory_guard_size {
310             config.static_memory_guard_size(size);
311         }
312 
313         if let Some(size) = self.dynamic_memory_guard_size {
314             config.dynamic_memory_guard_size(size);
315         }
316 
317         // If fuel has been configured, set the `consume fuel` flag on the config.
318         if self.fuel.is_some() {
319             config.consume_fuel(true);
320         }
321 
322         config.epoch_interruption(self.epoch_interruption);
323         config.generate_address_map(!self.disable_address_map);
324         #[cfg(feature = "memory-init-cow")]
325         config.memory_init_cow(!self.disable_memory_init_cow);
326 
327         #[cfg(feature = "pooling-allocator")]
328         {
329             if self.pooling_allocator {
330                 let instance_limits = InstanceLimits::default();
331                 config.allocation_strategy(wasmtime::InstanceAllocationStrategy::Pooling {
332                     strategy: PoolingAllocationStrategy::NextAvailable,
333                     instance_limits,
334                 });
335             }
336         }
337 
338         Ok(config)
339     }
340 
341     pub fn enable_wasm_features(&self, config: &mut Config) {
342         let WasmFeatures {
343             simd,
344             bulk_memory,
345             reference_types,
346             multi_value,
347             threads,
348             multi_memory,
349             memory64,
350             #[cfg(feature = "component-model")]
351             component_model,
352         } = self.wasm_features.unwrap_or_default();
353 
354         if let Some(enable) = simd {
355             config.wasm_simd(enable);
356         }
357         if let Some(enable) = bulk_memory {
358             config.wasm_bulk_memory(enable);
359         }
360         if let Some(enable) = reference_types {
361             config.wasm_reference_types(enable);
362         }
363         if let Some(enable) = multi_value {
364             config.wasm_multi_value(enable);
365         }
366         if let Some(enable) = threads {
367             config.wasm_threads(enable);
368         }
369         if let Some(enable) = multi_memory {
370             config.wasm_multi_memory(enable);
371         }
372         if let Some(enable) = memory64 {
373             config.wasm_memory64(enable);
374         }
375         #[cfg(feature = "component-model")]
376         if let Some(enable) = component_model {
377             config.wasm_component_model(enable);
378         }
379     }
380 
381     pub fn opt_level(&self) -> wasmtime::OptLevel {
382         match (self.optimize, self.opt_level.clone()) {
383             (true, _) => wasmtime::OptLevel::Speed,
384             (false, other) => other.unwrap_or(wasmtime::OptLevel::Speed),
385         }
386     }
387 }
388 
389 fn parse_opt_level(opt_level: &str) -> Result<wasmtime::OptLevel> {
390     match opt_level {
391         "s" => Ok(wasmtime::OptLevel::SpeedAndSize),
392         "0" => Ok(wasmtime::OptLevel::None),
393         "1" => Ok(wasmtime::OptLevel::Speed),
394         "2" => Ok(wasmtime::OptLevel::Speed),
395         other => bail!(
396             "unknown optimization level `{}`, only 0,1,2,s accepted",
397             other
398         ),
399     }
400 }
401 
402 #[derive(Default, Clone, Copy)]
403 #[cfg_attr(test, derive(Debug, PartialEq))]
404 pub struct WasmFeatures {
405     pub reference_types: Option<bool>,
406     pub multi_value: Option<bool>,
407     pub bulk_memory: Option<bool>,
408     pub simd: Option<bool>,
409     pub threads: Option<bool>,
410     pub multi_memory: Option<bool>,
411     pub memory64: Option<bool>,
412     #[cfg(feature = "component-model")]
413     pub component_model: Option<bool>,
414 }
415 
416 fn parse_wasm_features(features: &str) -> Result<WasmFeatures> {
417     let features = features.trim();
418 
419     let mut all = None;
420     let mut values: HashMap<_, _> = SUPPORTED_WASM_FEATURES
421         .iter()
422         .map(|(name, _)| (name.to_string(), None))
423         .collect();
424 
425     if features == "all" {
426         all = Some(true);
427     } else if features == "-all" {
428         all = Some(false);
429     } else {
430         for feature in features.split(',') {
431             let feature = feature.trim();
432 
433             if feature.is_empty() {
434                 continue;
435             }
436 
437             let (feature, value) = if feature.starts_with('-') {
438                 (&feature[1..], false)
439             } else {
440                 (feature, true)
441             };
442 
443             if feature == "all" {
444                 bail!("'all' cannot be specified with other WebAssembly features");
445             }
446 
447             match values.get_mut(feature) {
448                 Some(v) => *v = Some(value),
449                 None => bail!("unsupported WebAssembly feature '{}'", feature),
450             }
451         }
452     }
453 
454     Ok(WasmFeatures {
455         reference_types: all.or(values["reference-types"]),
456         multi_value: all.or(values["multi-value"]),
457         bulk_memory: all.or(values["bulk-memory"]),
458         simd: all.or(values["simd"]),
459         threads: all.or(values["threads"]),
460         multi_memory: all.or(values["multi-memory"]),
461         memory64: all.or(values["memory64"]),
462         #[cfg(feature = "component-model")]
463         component_model: all.or(values["component-model"]),
464     })
465 }
466 
467 fn parse_wasi_modules(modules: &str) -> Result<WasiModules> {
468     let modules = modules.trim();
469     match modules {
470         "default" => Ok(WasiModules::default()),
471         "-default" => Ok(WasiModules::none()),
472         _ => {
473             // Starting from the default set of WASI modules, enable or disable a list of
474             // comma-separated modules.
475             let mut wasi_modules = WasiModules::default();
476             let mut set = |module: &str, enable: bool| match module {
477                 "" => Ok(()),
478                 "wasi-common" => Ok(wasi_modules.wasi_common = enable),
479                 "experimental-wasi-nn" => Ok(wasi_modules.wasi_nn = enable),
480                 "experimental-wasi-crypto" => Ok(wasi_modules.wasi_crypto = enable),
481                 "default" => bail!("'default' cannot be specified with other WASI modules"),
482                 _ => bail!("unsupported WASI module '{}'", module),
483             };
484 
485             for module in modules.split(',') {
486                 let module = module.trim();
487                 let (module, value) = if module.starts_with('-') {
488                     (&module[1..], false)
489                 } else {
490                     (module, true)
491                 };
492                 set(module, value)?;
493             }
494 
495             Ok(wasi_modules)
496         }
497     }
498 }
499 
500 /// Select which WASI modules are available at runtime for use by Wasm programs.
501 #[derive(Debug, Clone, Copy, PartialEq)]
502 pub struct WasiModules {
503     /// Enable the wasi-common implementation; eventually this should be split into its separate
504     /// parts once the implementation allows for it (e.g. wasi-fs, wasi-clocks, etc.).
505     pub wasi_common: bool,
506 
507     /// Enable the experimental wasi-nn implementation.
508     pub wasi_nn: bool,
509 
510     /// Enable the experimental wasi-crypto implementation.
511     pub wasi_crypto: bool,
512 }
513 
514 impl Default for WasiModules {
515     fn default() -> Self {
516         Self {
517             wasi_common: true,
518             wasi_nn: false,
519             wasi_crypto: false,
520         }
521     }
522 }
523 
524 impl WasiModules {
525     /// Enable no modules.
526     pub fn none() -> Self {
527         Self {
528             wasi_common: false,
529             wasi_nn: false,
530             wasi_crypto: false,
531         }
532     }
533 }
534 
535 fn parse_cranelift_flag(name_and_value: &str) -> Result<(String, String)> {
536     let mut split = name_and_value.splitn(2, '=');
537     let name = if let Some(name) = split.next() {
538         name.to_string()
539     } else {
540         bail!("missing name in cranelift flag");
541     };
542     let value = if let Some(value) = split.next() {
543         value.to_string()
544     } else {
545         bail!("missing value in cranelift flag");
546     };
547     Ok((name, value))
548 }
549 
550 #[cfg(test)]
551 mod test {
552     use super::*;
553 
554     #[test]
555     fn test_all_features() -> Result<()> {
556         let options = CommonOptions::try_parse_from(vec!["foo", "--wasm-features=all"])?;
557 
558         let WasmFeatures {
559             reference_types,
560             multi_value,
561             bulk_memory,
562             simd,
563             threads,
564             multi_memory,
565             memory64,
566         } = options.wasm_features.unwrap();
567 
568         assert_eq!(reference_types, Some(true));
569         assert_eq!(multi_value, Some(true));
570         assert_eq!(bulk_memory, Some(true));
571         assert_eq!(simd, Some(true));
572         assert_eq!(threads, Some(true));
573         assert_eq!(multi_memory, Some(true));
574         assert_eq!(memory64, Some(true));
575 
576         Ok(())
577     }
578 
579     #[test]
580     fn test_no_features() -> Result<()> {
581         let options = CommonOptions::try_parse_from(vec!["foo", "--wasm-features=-all"])?;
582 
583         let WasmFeatures {
584             reference_types,
585             multi_value,
586             bulk_memory,
587             simd,
588             threads,
589             multi_memory,
590             memory64,
591         } = options.wasm_features.unwrap();
592 
593         assert_eq!(reference_types, Some(false));
594         assert_eq!(multi_value, Some(false));
595         assert_eq!(bulk_memory, Some(false));
596         assert_eq!(simd, Some(false));
597         assert_eq!(threads, Some(false));
598         assert_eq!(multi_memory, Some(false));
599         assert_eq!(memory64, Some(false));
600 
601         Ok(())
602     }
603 
604     #[test]
605     fn test_multiple_features() -> Result<()> {
606         let options = CommonOptions::try_parse_from(vec![
607             "foo",
608             "--wasm-features=-reference-types,simd,multi-memory,memory64",
609         ])?;
610 
611         let WasmFeatures {
612             reference_types,
613             multi_value,
614             bulk_memory,
615             simd,
616             threads,
617             multi_memory,
618             memory64,
619         } = options.wasm_features.unwrap();
620 
621         assert_eq!(reference_types, Some(false));
622         assert_eq!(multi_value, None);
623         assert_eq!(bulk_memory, None);
624         assert_eq!(simd, Some(true));
625         assert_eq!(threads, None);
626         assert_eq!(multi_memory, Some(true));
627         assert_eq!(memory64, Some(true));
628 
629         Ok(())
630     }
631 
632     macro_rules! feature_test {
633         ($test_name:ident, $name:ident, $flag:literal) => {
634             #[test]
635             fn $test_name() -> Result<()> {
636                 let options =
637                     CommonOptions::try_parse_from(vec!["foo", concat!("--wasm-features=", $flag)])?;
638 
639                 let WasmFeatures { $name, .. } = options.wasm_features.unwrap();
640 
641                 assert_eq!($name, Some(true));
642 
643                 let options = CommonOptions::try_parse_from(vec![
644                     "foo",
645                     concat!("--wasm-features=-", $flag),
646                 ])?;
647 
648                 let WasmFeatures { $name, .. } = options.wasm_features.unwrap();
649 
650                 assert_eq!($name, Some(false));
651 
652                 Ok(())
653             }
654         };
655     }
656 
657     feature_test!(
658         test_reference_types_feature,
659         reference_types,
660         "reference-types"
661     );
662     feature_test!(test_multi_value_feature, multi_value, "multi-value");
663     feature_test!(test_bulk_memory_feature, bulk_memory, "bulk-memory");
664     feature_test!(test_simd_feature, simd, "simd");
665     feature_test!(test_threads_feature, threads, "threads");
666     feature_test!(test_multi_memory_feature, multi_memory, "multi-memory");
667     feature_test!(test_memory64_feature, memory64, "memory64");
668 
669     #[test]
670     fn test_default_modules() {
671         let options = CommonOptions::try_parse_from(vec!["foo", "--wasi-modules=default"]).unwrap();
672         assert_eq!(
673             options.wasi_modules.unwrap(),
674             WasiModules {
675                 wasi_common: true,
676                 wasi_nn: false,
677                 wasi_crypto: false
678             }
679         );
680     }
681 
682     #[test]
683     fn test_empty_modules() {
684         let options = CommonOptions::try_parse_from(vec!["foo", "--wasi-modules="]).unwrap();
685         assert_eq!(
686             options.wasi_modules.unwrap(),
687             WasiModules {
688                 wasi_common: true,
689                 wasi_nn: false,
690                 wasi_crypto: false
691             }
692         );
693     }
694 
695     #[test]
696     fn test_some_modules() {
697         let options = CommonOptions::try_parse_from(vec![
698             "foo",
699             "--wasi-modules=experimental-wasi-nn,-wasi-common",
700         ])
701         .unwrap();
702         assert_eq!(
703             options.wasi_modules.unwrap(),
704             WasiModules {
705                 wasi_common: false,
706                 wasi_nn: true,
707                 wasi_crypto: false
708             }
709         );
710     }
711 
712     #[test]
713     fn test_no_modules() {
714         let options =
715             CommonOptions::try_parse_from(vec!["foo", "--wasi-modules=-default"]).unwrap();
716         assert_eq!(
717             options.wasi_modules.unwrap(),
718             WasiModules {
719                 wasi_common: false,
720                 wasi_nn: false,
721                 wasi_crypto: false
722             }
723         );
724     }
725 
726     #[test]
727     fn test_parse_from_str() {
728         fn use_func(flags: &str) -> CommonOptions {
729             CommonOptions::parse_from_str(flags).unwrap()
730         }
731         fn use_clap_parser(flags: &[&str]) -> CommonOptions {
732             CommonOptions::try_parse_from(flags).unwrap()
733         }
734 
735         assert_eq!(use_func(""), use_clap_parser(&[]));
736         assert_eq!(
737             use_func("--wasm-features=threads"),
738             use_clap_parser(&["foo", "--wasm-features=threads"])
739         );
740         assert_eq!(
741             use_func("--cranelift-set enable_simd=true"),
742             use_clap_parser(&["foo", "--cranelift-set", "enable_simd=true"])
743         );
744     }
745 }
746