rustc_target/spec/
json.rs

1use std::collections::BTreeMap;
2use std::str::FromStr;
3
4use rustc_abi::{Align, AlignFromBytesError};
5
6use super::crt_objects::CrtObjects;
7use super::{
8    BinaryFormat, CodeModel, DebuginfoKind, FloatAbi, FramePointer, LinkArgsCli,
9    LinkSelfContainedComponents, LinkSelfContainedDefault, LinkerFlavorCli, LldFlavor,
10    MergeFunctions, PanicStrategy, RelocModel, RelroLevel, RustcAbi, SanitizerSet,
11    SmallDataThresholdSupport, SplitDebuginfo, StackProbeType, StaticCow, SymbolVisibility, Target,
12    TargetKind, TargetOptions, TargetWarnings, TlsModel,
13};
14use crate::json::{Json, ToJson};
15use crate::spec::AbiMap;
16
17impl Target {
18    /// Loads a target descriptor from a JSON object.
19    pub fn from_json(json: &str) -> Result<(Target, TargetWarnings), String> {
20        let json_deserializer = &mut serde_json::Deserializer::from_str(json);
21
22        let json: TargetSpecJson =
23            serde_path_to_error::deserialize(json_deserializer).map_err(|err| err.to_string())?;
24
25        let mut base = Target {
26            llvm_target: json.llvm_target,
27            metadata: Default::default(),
28            pointer_width: json.target_pointer_width,
29            data_layout: json.data_layout,
30            arch: json.arch,
31            options: Default::default(),
32        };
33
34        // FIXME: This doesn't properly validate anything and just ignores the data if it's invalid.
35        // That's okay for now, the only use of this is when generating docs, which we don't do for
36        // custom targets.
37        if let Some(metadata) = json.metadata {
38            base.metadata.description = metadata.description;
39            base.metadata.tier = metadata.tier.filter(|tier| (1..=3).contains(tier));
40            base.metadata.host_tools = metadata.host_tools;
41            base.metadata.std = metadata.std;
42        }
43
44        let alignment_error = |field_name: &str, error: AlignFromBytesError| -> String {
45            let msg = match error {
46                AlignFromBytesError::NotPowerOfTwo(_) => "not a power of 2 number of bytes",
47                AlignFromBytesError::TooLarge(_) => "too large",
48            };
49            format!("`{}` bits is not a valid value for {field_name}: {msg}", error.align() * 8)
50        };
51
52        macro_rules! forward {
53            ($name:ident) => {
54                if let Some($name) = json.$name {
55                    base.$name = $name;
56                }
57            };
58        }
59        macro_rules! forward_opt {
60            ($name:ident) => {
61                if let Some($name) = json.$name {
62                    base.$name = Some($name);
63                }
64            };
65        }
66
67        if let Some(target_endian) = json.target_endian {
68            base.endian = target_endian.0;
69        }
70
71        forward!(frame_pointer);
72        forward!(c_int_width);
73        forward_opt!(c_enum_min_bits); // if None, matches c_int_width
74        forward!(os);
75        forward!(env);
76        forward!(abi);
77        forward!(vendor);
78        forward_opt!(linker);
79        forward!(linker_flavor_json);
80        forward!(lld_flavor_json);
81        forward!(linker_is_gnu_json);
82        forward!(pre_link_objects);
83        forward!(post_link_objects);
84        forward!(pre_link_objects_self_contained);
85        forward!(post_link_objects_self_contained);
86
87        // Deserializes the backwards-compatible variants of `-Clink-self-contained`
88        if let Some(link_self_contained) = json.link_self_contained_backwards_compatible {
89            base.link_self_contained = link_self_contained;
90        }
91        // Deserializes the components variant of `-Clink-self-contained`
92        if let Some(link_self_contained) = json.link_self_contained {
93            let components = link_self_contained
94                .components
95                .into_iter()
96                .fold(LinkSelfContainedComponents::empty(), |a, b| a | b);
97            base.link_self_contained = LinkSelfContainedDefault::WithComponents(components);
98        }
99
100        forward!(pre_link_args_json);
101        forward!(late_link_args_json);
102        forward!(late_link_args_dynamic_json);
103        forward!(late_link_args_static_json);
104        forward!(post_link_args_json);
105        forward_opt!(link_script);
106
107        if let Some(link_env) = json.link_env {
108            for s in link_env {
109                if let [k, v] = *s.split('=').collect::<Vec<_>>() {
110                    base.link_env.to_mut().push((k.to_string().into(), v.to_string().into()))
111                } else {
112                    return Err(format!("link-env value '{s}' must be of the pattern 'KEY=VALUE'"));
113                }
114            }
115        }
116
117        forward!(link_env_remove);
118        forward!(asm_args);
119        forward!(cpu);
120        forward!(need_explicit_cpu);
121        forward!(features);
122        forward!(dynamic_linking);
123        forward_opt!(direct_access_external_data);
124        forward!(dll_tls_export);
125        forward!(only_cdylib);
126        forward!(executables);
127        forward!(relocation_model);
128        forward_opt!(code_model);
129        forward!(tls_model);
130        forward!(disable_redzone);
131        forward!(function_sections);
132        forward!(dll_prefix);
133        forward!(dll_suffix);
134        forward!(exe_suffix);
135        forward!(staticlib_prefix);
136        forward!(staticlib_suffix);
137
138        if let Some(target_family) = json.target_family {
139            match target_family {
140                TargetFamiliesJson::Array(families) => base.families = families,
141                TargetFamiliesJson::String(family) => base.families = vec![family].into(),
142            }
143        }
144
145        forward!(abi_return_struct_as_int);
146        forward!(is_like_aix);
147        forward!(is_like_darwin);
148        forward!(is_like_solaris);
149        forward!(is_like_windows);
150        forward!(is_like_msvc);
151        forward!(is_like_wasm);
152        forward!(is_like_android);
153        forward!(is_like_vexos);
154        forward!(binary_format);
155        forward!(default_dwarf_version);
156        forward!(allows_weak_linkage);
157        forward!(has_rpath);
158        forward!(no_default_libraries);
159        forward!(position_independent_executables);
160        forward!(static_position_independent_executables);
161        forward!(plt_by_default);
162        forward!(relro_level);
163        forward!(archive_format);
164        forward!(allow_asm);
165        forward!(main_needs_argc_argv);
166        forward!(has_thread_local);
167        forward!(obj_is_bitcode);
168        forward_opt!(max_atomic_width);
169        forward_opt!(min_atomic_width);
170        forward!(atomic_cas);
171        forward!(panic_strategy);
172        forward!(crt_static_allows_dylibs);
173        forward!(crt_static_default);
174        forward!(crt_static_respected);
175        forward!(stack_probes);
176
177        if let Some(min_global_align) = json.min_global_align {
178            match Align::from_bits(min_global_align) {
179                Ok(align) => base.min_global_align = Some(align),
180                Err(e) => return Err(alignment_error("min-global-align", e)),
181            }
182        }
183
184        forward_opt!(default_codegen_units);
185        forward_opt!(default_codegen_backend);
186        forward!(trap_unreachable);
187        forward!(requires_lto);
188        forward!(singlethread);
189        forward!(no_builtins);
190        forward_opt!(default_visibility);
191        forward!(emit_debug_gdb_scripts);
192        forward!(requires_uwtable);
193        forward!(default_uwtable);
194        forward!(simd_types_indirect);
195        forward!(limit_rdylib_exports);
196        forward_opt!(override_export_symbols);
197        forward!(merge_functions);
198        forward!(mcount);
199        forward_opt!(llvm_mcount_intrinsic);
200        forward!(llvm_abiname);
201        forward_opt!(llvm_floatabi);
202        forward_opt!(rustc_abi);
203        forward!(relax_elf_relocations);
204        forward!(llvm_args);
205        forward!(use_ctors_section);
206        forward!(eh_frame_header);
207        forward!(has_thumb_interworking);
208        forward!(debuginfo_kind);
209        forward!(split_debuginfo);
210        forward!(supported_split_debuginfo);
211
212        if let Some(supported_sanitizers) = json.supported_sanitizers {
213            base.supported_sanitizers =
214                supported_sanitizers.into_iter().fold(SanitizerSet::empty(), |a, b| a | b);
215        }
216
217        forward!(generate_arange_section);
218        forward!(supports_stack_protector);
219        forward!(small_data_threshold_support);
220        forward!(entry_name);
221        forward!(supports_xray);
222
223        // we're going to run `update_from_cli`, but that won't change the target's AbiMap
224        // FIXME: better factor the Target definition so we enforce this on a type level
225        let abi_map = AbiMap::from_target(&base);
226        if let Some(entry_abi) = json.entry_abi {
227            base.options.entry_abi = abi_map.canonize_abi(entry_abi.0, false).unwrap();
228        }
229
230        base.update_from_cli();
231        base.check_consistency(TargetKind::Json)?;
232
233        Ok((base, TargetWarnings { unused_fields: vec![] }))
234    }
235}
236
237impl ToJson for Target {
238    fn to_json(&self) -> Json {
239        let mut d = serde_json::Map::new();
240        let default: TargetOptions = Default::default();
241        let mut target = self.clone();
242        target.update_to_cli();
243
244        macro_rules! target_val {
245            ($attr:ident) => {
246                target_val!($attr, (stringify!($attr)).replace("_", "-"))
247            };
248            ($attr:ident, $json_name:expr) => {{
249                let name = $json_name;
250                d.insert(name.into(), target.$attr.to_json());
251            }};
252        }
253
254        macro_rules! target_option_val {
255            ($attr:ident) => {{ target_option_val!($attr, (stringify!($attr)).replace("_", "-")) }};
256            ($attr:ident, $json_name:expr) => {{
257                let name = $json_name;
258                if default.$attr != target.$attr {
259                    d.insert(name.into(), target.$attr.to_json());
260                }
261            }};
262            (link_args - $attr:ident, $json_name:expr) => {{
263                let name = $json_name;
264                if default.$attr != target.$attr {
265                    let obj = target
266                        .$attr
267                        .iter()
268                        .map(|(k, v)| (k.desc().to_string(), v.clone()))
269                        .collect::<BTreeMap<_, _>>();
270                    d.insert(name.to_string(), obj.to_json());
271                }
272            }};
273            (env - $attr:ident) => {{
274                let name = (stringify!($attr)).replace("_", "-");
275                if default.$attr != target.$attr {
276                    let obj = target
277                        .$attr
278                        .iter()
279                        .map(|&(ref k, ref v)| format!("{k}={v}"))
280                        .collect::<Vec<_>>();
281                    d.insert(name, obj.to_json());
282                }
283            }};
284        }
285
286        target_val!(llvm_target);
287        target_val!(metadata);
288        target_val!(pointer_width, "target-pointer-width");
289        target_val!(arch);
290        target_val!(data_layout);
291
292        target_option_val!(endian, "target-endian");
293        target_option_val!(c_int_width, "target-c-int-width");
294        target_option_val!(os);
295        target_option_val!(env);
296        target_option_val!(abi);
297        target_option_val!(vendor);
298        target_option_val!(linker);
299        target_option_val!(linker_flavor_json, "linker-flavor");
300        target_option_val!(lld_flavor_json, "lld-flavor");
301        target_option_val!(linker_is_gnu_json, "linker-is-gnu");
302        target_option_val!(pre_link_objects);
303        target_option_val!(post_link_objects);
304        target_option_val!(pre_link_objects_self_contained, "pre-link-objects-fallback");
305        target_option_val!(post_link_objects_self_contained, "post-link-objects-fallback");
306        target_option_val!(link_args - pre_link_args_json, "pre-link-args");
307        target_option_val!(link_args - late_link_args_json, "late-link-args");
308        target_option_val!(link_args - late_link_args_dynamic_json, "late-link-args-dynamic");
309        target_option_val!(link_args - late_link_args_static_json, "late-link-args-static");
310        target_option_val!(link_args - post_link_args_json, "post-link-args");
311        target_option_val!(link_script);
312        target_option_val!(env - link_env);
313        target_option_val!(link_env_remove);
314        target_option_val!(asm_args);
315        target_option_val!(cpu);
316        target_option_val!(need_explicit_cpu);
317        target_option_val!(features);
318        target_option_val!(dynamic_linking);
319        target_option_val!(direct_access_external_data);
320        target_option_val!(dll_tls_export);
321        target_option_val!(only_cdylib);
322        target_option_val!(executables);
323        target_option_val!(relocation_model);
324        target_option_val!(code_model);
325        target_option_val!(tls_model);
326        target_option_val!(disable_redzone);
327        target_option_val!(frame_pointer);
328        target_option_val!(function_sections);
329        target_option_val!(dll_prefix);
330        target_option_val!(dll_suffix);
331        target_option_val!(exe_suffix);
332        target_option_val!(staticlib_prefix);
333        target_option_val!(staticlib_suffix);
334        target_option_val!(families, "target-family");
335        target_option_val!(abi_return_struct_as_int);
336        target_option_val!(is_like_aix);
337        target_option_val!(is_like_darwin);
338        target_option_val!(is_like_solaris);
339        target_option_val!(is_like_windows);
340        target_option_val!(is_like_msvc);
341        target_option_val!(is_like_wasm);
342        target_option_val!(is_like_android);
343        target_option_val!(is_like_vexos);
344        target_option_val!(binary_format);
345        target_option_val!(default_dwarf_version);
346        target_option_val!(allows_weak_linkage);
347        target_option_val!(has_rpath);
348        target_option_val!(no_default_libraries);
349        target_option_val!(position_independent_executables);
350        target_option_val!(static_position_independent_executables);
351        target_option_val!(plt_by_default);
352        target_option_val!(relro_level);
353        target_option_val!(archive_format);
354        target_option_val!(allow_asm);
355        target_option_val!(main_needs_argc_argv);
356        target_option_val!(has_thread_local);
357        target_option_val!(obj_is_bitcode);
358        target_option_val!(min_atomic_width);
359        target_option_val!(max_atomic_width);
360        target_option_val!(atomic_cas);
361        target_option_val!(panic_strategy);
362        target_option_val!(crt_static_allows_dylibs);
363        target_option_val!(crt_static_default);
364        target_option_val!(crt_static_respected);
365        target_option_val!(stack_probes);
366        target_option_val!(min_global_align);
367        target_option_val!(default_codegen_units);
368        target_option_val!(default_codegen_backend);
369        target_option_val!(trap_unreachable);
370        target_option_val!(requires_lto);
371        target_option_val!(singlethread);
372        target_option_val!(no_builtins);
373        target_option_val!(default_visibility);
374        target_option_val!(emit_debug_gdb_scripts);
375        target_option_val!(requires_uwtable);
376        target_option_val!(default_uwtable);
377        target_option_val!(simd_types_indirect);
378        target_option_val!(limit_rdylib_exports);
379        target_option_val!(override_export_symbols);
380        target_option_val!(merge_functions);
381        target_option_val!(mcount, "target-mcount");
382        target_option_val!(llvm_mcount_intrinsic);
383        target_option_val!(llvm_abiname);
384        target_option_val!(llvm_floatabi);
385        target_option_val!(rustc_abi);
386        target_option_val!(relax_elf_relocations);
387        target_option_val!(llvm_args);
388        target_option_val!(use_ctors_section);
389        target_option_val!(eh_frame_header);
390        target_option_val!(has_thumb_interworking);
391        target_option_val!(debuginfo_kind);
392        target_option_val!(split_debuginfo);
393        target_option_val!(supported_split_debuginfo);
394        target_option_val!(supported_sanitizers);
395        target_option_val!(c_enum_min_bits);
396        target_option_val!(generate_arange_section);
397        target_option_val!(supports_stack_protector);
398        target_option_val!(small_data_threshold_support);
399        target_option_val!(entry_name);
400        target_option_val!(entry_abi);
401        target_option_val!(supports_xray);
402
403        // Serializing `-Clink-self-contained` needs a dynamic key to support the
404        // backwards-compatible variants.
405        d.insert(self.link_self_contained.json_key().into(), self.link_self_contained.to_json());
406
407        Json::Object(d)
408    }
409}
410
411#[derive(serde_derive::Deserialize)]
412struct LinkSelfContainedComponentsWrapper {
413    components: Vec<LinkSelfContainedComponents>,
414}
415
416#[derive(serde_derive::Deserialize)]
417#[serde(untagged)]
418enum TargetFamiliesJson {
419    Array(StaticCow<[StaticCow<str>]>),
420    String(StaticCow<str>),
421}
422
423/// `Endian` is in `rustc_abi`, which doesn't have access to the macro and serde.
424struct EndianWrapper(rustc_abi::Endian);
425impl FromStr for EndianWrapper {
426    type Err = String;
427    fn from_str(s: &str) -> Result<Self, Self::Err> {
428        rustc_abi::Endian::from_str(s).map(Self)
429    }
430}
431crate::json::serde_deserialize_from_str!(EndianWrapper);
432
433/// `ExternAbi` is in `rustc_abi`, which doesn't have access to the macro and serde.
434struct ExternAbiWrapper(rustc_abi::ExternAbi);
435impl FromStr for ExternAbiWrapper {
436    type Err = String;
437    fn from_str(s: &str) -> Result<Self, Self::Err> {
438        rustc_abi::ExternAbi::from_str(s)
439            .map(Self)
440            .map_err(|_| format!("{s} is not a valid extern ABI"))
441    }
442}
443crate::json::serde_deserialize_from_str!(ExternAbiWrapper);
444
445#[derive(serde_derive::Deserialize)]
446struct TargetSpecJsonMetadata {
447    description: Option<StaticCow<str>>,
448    tier: Option<u64>,
449    host_tools: Option<bool>,
450    std: Option<bool>,
451}
452
453#[derive(serde_derive::Deserialize)]
454#[serde(rename_all = "kebab-case")]
455// Ensure that all unexpected fields get turned into errors.
456// This helps users stay up to date when the schema changes instead of silently
457// ignoring their old values.
458#[serde(deny_unknown_fields)]
459struct TargetSpecJson {
460    llvm_target: StaticCow<str>,
461    target_pointer_width: u16,
462    data_layout: StaticCow<str>,
463    arch: StaticCow<str>,
464
465    metadata: Option<TargetSpecJsonMetadata>,
466
467    // options:
468    target_endian: Option<EndianWrapper>,
469    frame_pointer: Option<FramePointer>,
470    #[serde(rename = "target-c-int-width")]
471    c_int_width: Option<u16>,
472    c_enum_min_bits: Option<u64>,
473    os: Option<StaticCow<str>>,
474    env: Option<StaticCow<str>>,
475    abi: Option<StaticCow<str>>,
476    vendor: Option<StaticCow<str>>,
477    linker: Option<StaticCow<str>>,
478    #[serde(rename = "linker-flavor")]
479    linker_flavor_json: Option<LinkerFlavorCli>,
480    #[serde(rename = "lld-flavor")]
481    lld_flavor_json: Option<LldFlavor>,
482    #[serde(rename = "linker-is-gnu")]
483    linker_is_gnu_json: Option<bool>,
484    #[serde(rename = "pre-link-objects")]
485    pre_link_objects: Option<CrtObjects>,
486    #[serde(rename = "post-link-objects")]
487    post_link_objects: Option<CrtObjects>,
488    #[serde(rename = "pre-link-objects-fallback")]
489    pre_link_objects_self_contained: Option<CrtObjects>,
490    #[serde(rename = "post-link-objects-fallback")]
491    post_link_objects_self_contained: Option<CrtObjects>,
492    #[serde(rename = "crt-objects-fallback")]
493    link_self_contained_backwards_compatible: Option<LinkSelfContainedDefault>,
494    link_self_contained: Option<LinkSelfContainedComponentsWrapper>,
495    #[serde(rename = "pre-link-args")]
496    pre_link_args_json: Option<LinkArgsCli>,
497    #[serde(rename = "late-link-args")]
498    late_link_args_json: Option<LinkArgsCli>,
499    #[serde(rename = "late-link-args-dynamic")]
500    late_link_args_dynamic_json: Option<LinkArgsCli>,
501    #[serde(rename = "late-link-args-static")]
502    late_link_args_static_json: Option<LinkArgsCli>,
503    #[serde(rename = "post-link-args")]
504    post_link_args_json: Option<LinkArgsCli>,
505    link_script: Option<StaticCow<str>>,
506    link_env: Option<Vec<StaticCow<str>>>,
507    link_env_remove: Option<StaticCow<[StaticCow<str>]>>,
508    asm_args: Option<StaticCow<[StaticCow<str>]>>,
509    cpu: Option<StaticCow<str>>,
510    need_explicit_cpu: Option<bool>,
511    features: Option<StaticCow<str>>,
512    dynamic_linking: Option<bool>,
513    direct_access_external_data: Option<bool>,
514    dll_tls_export: Option<bool>,
515    only_cdylib: Option<bool>,
516    executables: Option<bool>,
517    relocation_model: Option<RelocModel>,
518    code_model: Option<CodeModel>,
519    tls_model: Option<TlsModel>,
520    disable_redzone: Option<bool>,
521    function_sections: Option<bool>,
522    dll_prefix: Option<StaticCow<str>>,
523    dll_suffix: Option<StaticCow<str>>,
524    exe_suffix: Option<StaticCow<str>>,
525    staticlib_prefix: Option<StaticCow<str>>,
526    staticlib_suffix: Option<StaticCow<str>>,
527    target_family: Option<TargetFamiliesJson>,
528    abi_return_struct_as_int: Option<bool>,
529    is_like_aix: Option<bool>,
530    is_like_darwin: Option<bool>,
531    is_like_solaris: Option<bool>,
532    is_like_windows: Option<bool>,
533    is_like_msvc: Option<bool>,
534    is_like_wasm: Option<bool>,
535    is_like_android: Option<bool>,
536    is_like_vexos: Option<bool>,
537    binary_format: Option<BinaryFormat>,
538    default_dwarf_version: Option<u32>,
539    allows_weak_linkage: Option<bool>,
540    has_rpath: Option<bool>,
541    no_default_libraries: Option<bool>,
542    position_independent_executables: Option<bool>,
543    static_position_independent_executables: Option<bool>,
544    plt_by_default: Option<bool>,
545    relro_level: Option<RelroLevel>,
546    archive_format: Option<StaticCow<str>>,
547    allow_asm: Option<bool>,
548    main_needs_argc_argv: Option<bool>,
549    has_thread_local: Option<bool>,
550    obj_is_bitcode: Option<bool>,
551    max_atomic_width: Option<u64>,
552    min_atomic_width: Option<u64>,
553    atomic_cas: Option<bool>,
554    panic_strategy: Option<PanicStrategy>,
555    crt_static_allows_dylibs: Option<bool>,
556    crt_static_default: Option<bool>,
557    crt_static_respected: Option<bool>,
558    stack_probes: Option<StackProbeType>,
559    min_global_align: Option<u64>,
560    default_codegen_units: Option<u64>,
561    default_codegen_backend: Option<StaticCow<str>>,
562    trap_unreachable: Option<bool>,
563    requires_lto: Option<bool>,
564    singlethread: Option<bool>,
565    no_builtins: Option<bool>,
566    default_visibility: Option<SymbolVisibility>,
567    emit_debug_gdb_scripts: Option<bool>,
568    requires_uwtable: Option<bool>,
569    default_uwtable: Option<bool>,
570    simd_types_indirect: Option<bool>,
571    limit_rdylib_exports: Option<bool>,
572    override_export_symbols: Option<StaticCow<[StaticCow<str>]>>,
573    merge_functions: Option<MergeFunctions>,
574    #[serde(rename = "target-mcount")]
575    mcount: Option<StaticCow<str>>,
576    llvm_mcount_intrinsic: Option<StaticCow<str>>,
577    llvm_abiname: Option<StaticCow<str>>,
578    llvm_floatabi: Option<FloatAbi>,
579    rustc_abi: Option<RustcAbi>,
580    relax_elf_relocations: Option<bool>,
581    llvm_args: Option<StaticCow<[StaticCow<str>]>>,
582    use_ctors_section: Option<bool>,
583    eh_frame_header: Option<bool>,
584    has_thumb_interworking: Option<bool>,
585    debuginfo_kind: Option<DebuginfoKind>,
586    split_debuginfo: Option<SplitDebuginfo>,
587    supported_split_debuginfo: Option<StaticCow<[SplitDebuginfo]>>,
588    supported_sanitizers: Option<Vec<SanitizerSet>>,
589    generate_arange_section: Option<bool>,
590    supports_stack_protector: Option<bool>,
591    small_data_threshold_support: Option<SmallDataThresholdSupport>,
592    entry_name: Option<StaticCow<str>>,
593    supports_xray: Option<bool>,
594    entry_abi: Option<ExternAbiWrapper>,
595}
rustc_target/spec/json.rs

rustc_target/spec/
json.rs
