Add --print target-spec-json-schema #144498

Noratrieb · 2025-07-26T10:42:53Z

This schema is helpful for people writing custom target spec JSON. It can provide autocomplete in the editor, and also serves as documentation when there are documentation comments on the structs, as schemars will put them in the schema.

I was motivated to do this because I saw someone write their own version of this schema by hand, so demand for this clearly exists. It's not a lot of effort to implement, so I thought it would make sense.

MCP: rust-lang/compiler-team#905

I think it would also be useful to put this in the sysroot in etc so people can link it directly in their editors.

I would have loved to add a test that validates the JSON schema against the spec JSON of every builtin target, but I don't want to do it as the JSON schema validation crates have incredible amounts of dependencies because JSON schema supports a ton of random features. I don't want to add that, even as a dev dependency.

compiler/rustc_target/src/lib.rs

With this macro we only need to enumerate every variant once. This saves a lot of duplication already between the definition, the `FromStr` impl and the `ToJson` impl. It also enables us to do further things with it like JSON schema generation.

rustbot · 2025-07-27T17:53:01Z

r? @fee1-dead

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rustbot · 2025-07-27T17:53:03Z

Some changes occurred in compiler/rustc_codegen_ssa

cc @WaffleLapkin

The list of allowed third-party dependencies may have been modified! You must ensure that any new dependencies have compatible licenses before merging.

cc @davidtwco, @wesleywiser

These commits modify the Cargo.lock file. Unintentional changes to Cargo.lock can be introduced when switching branches and rebasing PRs.

If this was unintentional then you should revert the changes before this PR is merged.
Otherwise, you can ignore this comment.

These commits modify compiler targets.
(See the Target Tier Policy.)

This PR modifies run-make tests.

cc @jieyouxu

There are changes to the tidy tool.

cc @jieyouxu

Noratrieb · 2025-07-27T17:53:28Z

The MCP isn't accepted yet, but that doesn't need to stop anyone from reviewing.
r? jieyouxu maybe you want to review it since it also touches bootstrap?

rustbot · 2025-07-27T17:53:32Z

jieyouxu is currently at their maximum review capacity.
They may take a while to respond.

jieyouxu · 2025-07-28T05:40:49Z

I can probably review it after the MCP passes.

jieyouxu

Thanks, looks good to me overall, a few questions

compiler/rustc_target/src/spec/mod.rs

jieyouxu · 2025-07-29T04:02:55Z

src/tools/tidy/src/deps.rs

@@ -361,6 +362,8 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
    "rand_xorshift", // dependency for doc-tests in rustc_thread_pool
    "rand_xoshiro",
    "redox_syscall",
+    "ref-cast",


Remark: at least this uses rustc version detection, not just nightly detection

https://github.com/dtolnay/ref-cast/blob/1.0.24/build.rs

jieyouxu · 2025-07-29T04:07:43Z

None of them are blocking, so feel free to r=me once the MCP is accepted.

jieyouxu

Looks good

Noratrieb · 2025-08-05T17:09:15Z

@bors r=jieyouxu

bors · 2025-08-05T17:09:18Z

📌 Commit 1dfa421 has been approved by jieyouxu

It is now in the queue for this repository.

…youxu Add --print target-spec-json-schema This schema is helpful for people writing custom target spec JSON. It can provide autocomplete in the editor, and also serves as documentation when there are documentation comments on the structs, as `schemars` will put them in the schema. I was motivated to do this because I saw someone write their own version of this schema by hand, so demand for this clearly exists. It's not a lot of effort to implement, so I thought it would make sense. MCP: rust-lang/compiler-team#905 I think it would also be useful to put this in the sysroot in `etc` so people can link it directly in their editors. I would have loved to add a test that validates the JSON schema against the spec JSON of every builtin target, but I don't want to do it as the JSON schema validation crates have incredible amounts of dependencies because JSON schema supports a ton of random features. I don't want to add that, even as a dev dependency.

Rollup of 21 pull requests Successful merges: - #137831 (Tweak auto trait errors) - #138689 (add nvptx_target_feature) - #140267 (implement continue_ok and break_ok for ControlFlow) - #143679 (Preserve the .debug_gdb_scripts section) - #143857 (Port #[macro_export] to the new attribute parsing infrastructure) - #143929 (Mark all deprecation lints in name resolution as deny-by-default and report-in-deps) - #144133 (Stabilize const TypeId::of) - #144369 (Upgrade semicolon_in_expressions_from_macros from warn to deny) - #144473 (Address libunwind.a inconsistency issues in the bootstrap program) - #144498 (Add --print target-spec-json-schema) - #144552 (Rehome 33 `tests/ui/issues/` tests to other subdirectories under `tests/ui/`) - #144659 (bootstrap: refactor mingw dist and fix gnullvm) - #144676 (Add documentation for unstable_feature_bound) - #144794 (Port `#[coroutine]` to the new attribute system) - #144835 (Anonymize binders in tail call sig) - #144836 (Change visibility of Args new function) - #144861 (Stabilize `panic_payload_as_str` feature) - #144910 (Add regression tests for seemingly fixed issues) - #144913 ([rustdoc] Fix wrong `i` tooltip icon) - #144917 (Enforce tail call type is related to body return type in borrowck) - #144924 (compiletest: add hint for when a ui test produces no errors) r? `@ghost` `@rustbot` modify labels: rollup

…youxu Add --print target-spec-json-schema This schema is helpful for people writing custom target spec JSON. It can provide autocomplete in the editor, and also serves as documentation when there are documentation comments on the structs, as `schemars` will put them in the schema. I was motivated to do this because I saw someone write their own version of this schema by hand, so demand for this clearly exists. It's not a lot of effort to implement, so I thought it would make sense. MCP: rust-lang/compiler-team#905 I think it would also be useful to put this in the sysroot in `etc` so people can link it directly in their editors. I would have loved to add a test that validates the JSON schema against the spec JSON of every builtin target, but I don't want to do it as the JSON schema validation crates have incredible amounts of dependencies because JSON schema supports a ton of random features. I don't want to add that, even as a dev dependency.

Zalathar · 2025-08-07T03:58:44Z

Still trying to track down #144995 (comment)

@bors try jobs=dist-ohos-x86_64

rust-bors · 2025-08-07T03:58:48Z

⌛ Trying commit 1dfa421 with merge 3099bf1…

To cancel the try build, run the command @bors try cancel.

Add --print target-spec-json-schema try-job: dist-ohos-x86_64

rust-log-analyzer · 2025-08-07T04:56:45Z

The job dist-ohos-x86_64 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

##[endgroup]
[TIMING] core::build_steps::tool::ToolBuild { build_compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu, forced_compiler: true }, target: x86_64-unknown-linux-ohos, tool: "rust-analyzer-proc-macro-srv", path: "src/tools/rust-analyzer/crates/proc-macro-srv-cli", mode: ToolRustc, source_type: InTree, extra_features: ["in-rust-tree"], allow_features: "rustc_private,proc_macro_internals,proc_macro_diagnostic,proc_macro_span,proc_macro_span_shrink,proc_macro_def_site", cargo_args: [], artifact_kind: Binary } -- 62.380
[TIMING] core::build_steps::tool::RustAnalyzerProcMacroSrv { compilers: RustcPrivateCompilers { build_compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu, forced_compiler: true }, target_compiler: Compiler { stage: 2, host: x86_64-unknown-linux-ohos, forced_compiler: false } } } -- 0.000
[TIMING] core::build_steps::dist::DebuggerScripts { sysroot: "/checkout/obj/build/tmp/tarball/rustc/x86_64-unknown-linux-ohos/image", host: x86_64-unknown-linux-ohos } -- 0.003
Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:45:30
  local time: Thu Aug  7 04:56:33 UTC 2025
  network time: Thu, 07 Aug 2025 04:56:33 GMT
##[error]Process completed with exit code 1.
Post job cleanup.

rust-bors · 2025-08-07T04:56:56Z

💔 Test failed (CI). Failed jobs:

bors build finished (web logs, extended logs)
try - dist-ohos-x86_64 (web logs, extended logs)

Zalathar · 2025-08-07T05:00:50Z

This PR seems to be the cause of the mysterious failure; probably something in the TargetSpecJsonSchema step.

@bors r-

Noratrieb · 2025-08-07T05:12:14Z

wtf

Zalathar · 2025-08-07T05:19:21Z

Might be worth trying some other dist jobs, in case the ohos job just happened to get unlucky by encountering the failure before anyone else.

jieyouxu · 2025-08-07T05:23:48Z

src/bootstrap/src/core/build_steps/dist.rs

+
+    /// Copies the output of --print=target-spec-json-schema into etc.
+    fn run(self, builder: &Builder<'_>) {
+        let mut rustc = command(builder.rustc(self.compiler)).fail_fast();


I'll need to check which compiler is used

For a stage 2 cross build it would still need to use the stage 1 compiler since that's on the host, that might be the problem..

Noratrieb · 2025-08-07T05:35:05Z

Could be because of cross compilation maybe, let's try a more linux job to confirm
@bors try jobs=dist-loongarch64-linux

rust-bors · 2025-08-07T05:35:09Z

⌛ Trying commit 1dfa421 with merge 33b5cc8…

To cancel the try build, run the command @bors try cancel.

Add --print target-spec-json-schema try-job: dist-loongarch64-linux

rust-bors · 2025-08-07T06:36:30Z

💔 Test failed (CI). Failed jobs:

bors build finished (web logs, extended logs)
try - dist-loongarch64-linux (web logs, extended logs)

rust-log-analyzer · 2025-08-07T06:46:30Z

The job dist-loongarch64-linux failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

##[endgroup]
[TIMING] core::build_steps::tool::ToolBuild { build_compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu, forced_compiler: true }, target: loongarch64-unknown-linux-gnu, tool: "rust-analyzer-proc-macro-srv", path: "src/tools/rust-analyzer/crates/proc-macro-srv-cli", mode: ToolRustc, source_type: InTree, extra_features: ["in-rust-tree"], allow_features: "rustc_private,proc_macro_internals,proc_macro_diagnostic,proc_macro_span,proc_macro_span_shrink,proc_macro_def_site", cargo_args: [], artifact_kind: Binary } -- 59.265
[TIMING] core::build_steps::tool::RustAnalyzerProcMacroSrv { compilers: RustcPrivateCompilers { build_compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu, forced_compiler: true }, target_compiler: Compiler { stage: 2, host: loongarch64-unknown-linux-gnu, forced_compiler: false } } } -- 0.000
[TIMING] core::build_steps::dist::DebuggerScripts { sysroot: "/checkout/obj/build/tmp/tarball/rustc/loongarch64-unknown-linux-gnu/image", host: loongarch64-unknown-linux-gnu } -- 0.003
Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:51:54
  local time: Thu Aug  7 06:36:09 UTC 2025
  network time: Thu, 07 Aug 2025 06:36:09 GMT
##[error]Process completed with exit code 1.
Post job cleanup.

rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Jul 26, 2025

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Noratrieb mentioned this pull request Jul 26, 2025

Add JSON schema for target spec JSON rust-lang/compiler-team#905

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Noratrieb commented Jul 26, 2025

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Noratrieb force-pushed the rustc-json-schema branch from 547cba8 to d6acb28 Compare July 26, 2025 22:15

rustbot added A-tidy Area: The tidy tool T-bootstrap Relevant to the bootstrap subteam: Rust's build system (x.py and src/bootstrap) labels Jul 26, 2025

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Noratrieb force-pushed the rustc-json-schema branch from d6acb28 to 8f1abd3 Compare July 27, 2025 11:33

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Noratrieb force-pushed the rustc-json-schema branch from 8f1abd3 to a07cfd1 Compare July 27, 2025 12:18

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Noratrieb force-pushed the rustc-json-schema branch from a07cfd1 to d4383c1 Compare July 27, 2025 13:42

rustbot added the A-run-make Area: port run-make Makefiles to rmake.rs label Jul 27, 2025

Noratrieb marked this pull request as ready for review July 27, 2025 17:52

rustbot assigned fee1-dead Jul 27, 2025

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Jul 27, 2025

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jieyouxu removed the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jul 29, 2025

Noratrieb force-pushed the rustc-json-schema branch from d4383c1 to 1dfa421 Compare August 1, 2025 21:43

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jieyouxu removed the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Aug 5, 2025

bors added the S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. label Aug 5, 2025

Zalathar mentioned this pull request Aug 6, 2025

Rollup of 21 pull requests #144995

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Zalathar mentioned this pull request Aug 7, 2025

Rollup of 21 pull requests #145034

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rust-bors bot added a commit that referenced this pull request Aug 7, 2025

Auto merge of #144498 - Noratrieb:rustc-json-schema, r=<try>

3099bf1

Add --print target-spec-json-schema try-job: dist-ohos-x86_64

bors added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Aug 7, 2025

Zalathar mentioned this pull request Aug 7, 2025

Rollup of 20 pull requests #145039

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Auto merge of #144498 - Noratrieb:rustc-json-schema, r=<try>

33b5cc8

Add --print target-spec-json-schema try-job: dist-loongarch64-linux

Add --print target-spec-json-schema #144498

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Add --print target-spec-json-schema #144498

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