rustdoc: Represent `--output-format=json` coverage and ir differently by aDotInTheVoid · Pull Request #154445 · rust-lang/rust

aDotInTheVoid · 2026-03-27T00:40:46Z

--output-format=json does a few different things:

By itself, it emits a JSON representation of a crate's API ("IR
JSON").
When used with --show-coverage, it prints the doc coverage as JSON,
instead of an ASCII table ("Coverage JSON").

These two cases need to be handled entirely differently. There's no
overlapping code, they just are called the same way.

By making these separate variants, we don't need to check the
show_coverage variable each time we check is_json, which makes it
harder to write a bug that checks for IR JSON, and accidentally happens in
coverage JSON too.

Also, as a driveby, improves some instability error messages, and cleans
up their tests, and adds other related tests.

rustbot · 2026-03-27T00:40:51Z

r? @notriddle

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aDotInTheVoid · 2026-06-19T01:42:32Z

@rustbot author

notriddle · 2026-06-19T05:16:15Z

Assign to someone who knows more about this:

r? Urgau

Urgau

Thanks for the cleanup. Looks good to me.

View changes since this review

Urgau · 2026-06-19T16:09:32Z

r=me after fixing CI

aDotInTheVoid · 2026-07-07T23:15:04Z

This has changed enough that it probably needs re-review.

@rustbot ready

`--output-format=json` does a few different things: - By itself, it emits a JSON representation of a crate's API ("IR JSON"). - When used with `--show-coverage`, it prints the doc coverage as JSON, instead of an ASCII table ("Coverage JSON"). These two cases need to be handled entirely differently. There's no overlapping code, they just are called the same way. By making these separate variants, we don't need to check the `show_coverage` variable each time we check `is_json`, which makes it harder to write a bug that checks for IR JSON, and accidentally happens in coverage JSON too. Also, as a driveby, improves some instability error messages, and cleans up their tests, and adds other related tests.

aDotInTheVoid · 2026-07-07T23:43:00Z

                match typ {
                    EmitType::DepInfo(_) => match output_format {
-                        OutputFormat::Json | OutputFormat::Html => {}
+                        OutputFormat::Html | OutputFormat::IrJson | OutputFormat::CoverageJson => {}


I don't think this is actually correct as --emit=dep-info makes no sense for --show-coverage (which only goes to stdout). I've filed #158929 to track doing this, as that fix should be a separate PR.

View changes since the review

Indeed this seems weird. I agree that we should probably disallow --emit=dep-info with --show-coverage.

Urgau

Looks good to me.

View changes since this review

Urgau · 2026-07-08T18:29:43Z

@bors r+

rust-bors · 2026-07-08T18:29:46Z

📌 Commit d2ee4ca has been approved by Urgau

It is now in the queue for this repository.

🌲 The tree is currently closed for pull requests below priority 10. This pull request will be tested once the tree is reopened.

Reason for tree closure: spurious failures

rustdoc: Represent `--output-format=json` coverage and ir differently `--output-format=json` does a few different things: - By itself, it emits a JSON representation of a crate's API ("IR JSON"). - When used with `--show-coverage`, it prints the doc coverage as JSON, instead of an ASCII table ("Coverage JSON"). These two cases need to be handled entirely differently. There's no overlapping code, they just are called the same way. By making these separate variants, we don't need to check the `show_coverage` variable each time we check `is_json`, which makes it harder to write a bug that checks for IR JSON, and accidentally happens in coverage JSON too. Also, as a driveby, improves some instability error messages, and cleans up their tests, and adds other related tests.

…uwer Rollup of 25 pull requests Successful merges: - #158871 (add relnotes for 1.97.0) - #158968 (stdarch subtree update) - #154445 (rustdoc: Represent `--output-format=json` coverage and ir differently) - #156370 (Reject linked dylib EII default overrides) - #157153 (allow `Allocator`s to be used as `#[global_allocator]`s) - #158495 (Rename HAS_CT_PROJECTION to HAS_CONST_ALIAS) - #158617 (allow mGCA const arguments to fall back to anon consts) - #158645 (Fix splat ICEs and ban it in closures) - #158655 (Fix coroutine MIR saved local remapping) - #158666 (Carry the `b_offset` inside `BackendRepr::ScalarPair`) - #158912 (Introduce new bootstrap config section for PGO configuration) - #158920 (Update wasm-component-ld to 0.5.26) - #158926 (wrapping_sh* methods: clarify underspecified reference) - #158927 (add core test run with `-Zforce-intrinsic-fallback`) - #158932 (Do not build the compiler when invoking `x perf compare`) - #158937 (Emit the emscripten entry point as `__main_argc_argv`) - #151379 (Stabilize `VecDeque::retain_back` from `truncate_front`) - #156548 ( Library support for aarch64-unknown-linux-pauthtest target) - #158307 (CI job for parallel frontend ui tests) - #158347 (Improve generic parameters handling for #[diagnostic::on_const]) - #158722 (delegation: do not always inherit `ConstArgHasType` predicates) - #158741 (Simplify `Option::into_flat_iter` signature) - #158807 (Add regression test for CString::clone_into unwind safety) - #158862 (Fix the span for parameter suggestion ) - #158883 (tests: fix enum-match.rs to handle LLVM 23)

rustdoc: Represent `--output-format=json` coverage and ir differently `--output-format=json` does a few different things: - By itself, it emits a JSON representation of a crate's API ("IR JSON"). - When used with `--show-coverage`, it prints the doc coverage as JSON, instead of an ASCII table ("Coverage JSON"). These two cases need to be handled entirely differently. There's no overlapping code, they just are called the same way. By making these separate variants, we don't need to check the `show_coverage` variable each time we check `is_json`, which makes it harder to write a bug that checks for IR JSON, and accidentally happens in coverage JSON too. Also, as a driveby, improves some instability error messages, and cleans up their tests, and adds other related tests.

Rollup of 25 pull requests Successful merges: - #158871 (add relnotes for 1.97.0) - #158968 (stdarch subtree update) - #157690 (codegen_ssa: pack small const aggregates into immediate stores) - #158541 (Move `std::io::Write` to `core::io`) - #154445 (rustdoc: Represent `--output-format=json` coverage and ir differently) - #156370 (Reject linked dylib EII default overrides) - #157153 (allow `Allocator`s to be used as `#[global_allocator]`s) - #158495 (Rename HAS_CT_PROJECTION to HAS_CONST_ALIAS) - #158617 (allow mGCA const arguments to fall back to anon consts) - #158645 (Fix splat ICEs and ban it in closures) - #158655 (Fix coroutine MIR saved local remapping) - #158666 (Carry the `b_offset` inside `BackendRepr::ScalarPair`) - #158870 (std: merge the unix-like io::error modules into one file) - #158920 (Update wasm-component-ld to 0.5.26) - #158926 (wrapping_sh* methods: clarify underspecified reference) - #158927 (add core test run with `-Zforce-intrinsic-fallback`) - #158932 (Do not build the compiler when invoking `x perf compare`) - #158937 (Emit the emscripten entry point as `__main_argc_argv`) - #151379 (Stabilize `VecDeque::retain_back` from `truncate_front`) - #156144 (Better docs for PartialEq (includes macro rename)) - #156548 ( Library support for aarch64-unknown-linux-pauthtest target) - #158307 (CI job for parallel frontend ui tests) - #158347 (Improve generic parameters handling for #[diagnostic::on_const]) - #158722 (delegation: do not always inherit `ConstArgHasType` predicates) - #158741 (Simplify `Option::into_flat_iter` signature)

rustdoc: Represent `--output-format=json` coverage and ir differently `--output-format=json` does a few different things: - By itself, it emits a JSON representation of a crate's API ("IR JSON"). - When used with `--show-coverage`, it prints the doc coverage as JSON, instead of an ASCII table ("Coverage JSON"). These two cases need to be handled entirely differently. There's no overlapping code, they just are called the same way. By making these separate variants, we don't need to check the `show_coverage` variable each time we check `is_json`, which makes it harder to write a bug that checks for IR JSON, and accidentally happens in coverage JSON too. Also, as a driveby, improves some instability error messages, and cleans up their tests, and adds other related tests.

Rollup of 23 pull requests Successful merges: - #158968 (stdarch subtree update) - #154445 (rustdoc: Represent `--output-format=json` coverage and ir differently) - #158495 (Rename HAS_CT_PROJECTION to HAS_CONST_ALIAS) - #158666 (Carry the `b_offset` inside `BackendRepr::ScalarPair`) - #158870 (std: merge the unix-like io::error modules into one file) - #158920 (Update wasm-component-ld to 0.5.26) - #158926 (wrapping_sh* methods: clarify underspecified reference) - #158927 (add core test run with `-Zforce-intrinsic-fallback`) - #158932 (Do not build the compiler when invoking `x perf compare`) - #158937 (Emit the emscripten entry point as `__main_argc_argv`) - #151379 (Stabilize `VecDeque::retain_back` from `truncate_front`) - #156144 (Better docs for PartialEq (includes macro rename)) - #156548 ( Library support for aarch64-unknown-linux-pauthtest target) - #157995 (`Vec::dedup_by` docs explicit function argument order) - #158307 (CI job for parallel frontend ui tests) - #158741 (Simplify `Option::into_flat_iter` signature) - #158807 (Add regression test for CString::clone_into unwind safety) - #158862 (Fix the span for parameter suggestion ) - #158894 (Make the ordering of non-terminal binds in ambiguity error messages deterministic) - #158902 (add codegen test for range length bound propagation) - #158913 (Update `browser-ui-test` version to `0.24.1`) - #158935 (std: support real fd methods on Emscripten) - #158978 (Add regression test for too-big by-value ABI args)

Rollup merge of #154445 - aDotInTheVoid:better-enum, r=Urgau rustdoc: Represent `--output-format=json` coverage and ir differently `--output-format=json` does a few different things: - By itself, it emits a JSON representation of a crate's API ("IR JSON"). - When used with `--show-coverage`, it prints the doc coverage as JSON, instead of an ASCII table ("Coverage JSON"). These two cases need to be handled entirely differently. There's no overlapping code, they just are called the same way. By making these separate variants, we don't need to check the `show_coverage` variable each time we check `is_json`, which makes it harder to write a bug that checks for IR JSON, and accidentally happens in coverage JSON too. Also, as a driveby, improves some instability error messages, and cleans up their tests, and adds other related tests.

rustbot assigned notriddle Mar 27, 2026

aDotInTheVoid added the A-rustdoc-json Area: Rustdoc JSON backend label Mar 30, 2026

apiraino removed the T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. label May 14, 2026

rust-cloud-vms Bot force-pushed the better-enum branch from 5e04d7c to c2505e6 Compare June 19, 2026 00:41

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aDotInTheVoid changed the title ~~rustdoc: Repersent --output-format=json coverage and ir diferently~~ rustdoc: Represent --output-format=json coverage and ir differently Jul 7, 2026

aDotInTheVoid commented Jul 7, 2026

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JonathanBrouwer mentioned this pull request Jul 8, 2026

Rollup of 14 pull requests #158971

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Rollup of 25 pull requests #158973

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Rollup of 25 pull requests #158977

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Rollup of 25 pull requests #158986

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This was referenced Jul 9, 2026

Rollup of 25 pull requests #158989

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Rollup of 23 pull requests #158991

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rust-bors Bot merged commit 470853e into rust-lang:main Jul 9, 2026
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