Introduce MSRV for lints, and lint against cfg(any()/all()) on Rust 1.88+

[clubby789]

Split out from #149791

Currently duplicates a custom simple version parser, could instead add a dep on semver to do parsing.

• Adds an optional msrv field to DiagCtxtInner, parsed from CARGO_PKG_RUST_VERSION if present
• Adds an optional rust_version field to DiagInner, controlled by adding , msrv = "1.xx.0" to a #[diag]
• Avoid emitting diagnostics for if their rust_version is > msrv

[rustbot]

rustc_macros::diagnostics was changed

cc @davidtwco, @compiler-errors, @TaKO8Ki

The Miri subtree was changed

cc @rust-lang/miri

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann

This PR modifies tests/ui/issues/. If this PR is adding new tests to tests/ui/issues/,
please refrain from doing so, and instead add it to more descriptive subdirectories.

[rustbot]

r? @mati865

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[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[rust-log-analyzer]

The job aarch64-gnu-llvm-20-1 failed! Check out the build log: (web) (plain enhanced) (plain)

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

---- [ui] tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs stdout ----
Saved the actual stderr to `/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui-fulldeps/session-diagnostic/diagnostic-derive/diagnostic-derive.stderr`
diff of stderr:

62 LL | #[diag(nonsense = "...", code = E0123, slug = "foo")]
63    |        ^^^^^^^^
64    |
-    = note: only the `code` parameter is valid after the slug
+    = note: only `code` or `msrv`are valid after the slug
66 
67 error: derive(Diagnostic): diagnostic slug not specified
68   --> $DIR/diagnostic-derive.rs:86:1

78 LL | #[diag(nonsense = 4, code = E0123, slug = "foo")]
79    |        ^^^^^^^^
80    |
-    = note: only the `code` parameter is valid after the slug
+    = note: only `code` or `msrv`are valid after the slug
82 
83 error: derive(Diagnostic): diagnostic slug not specified
84   --> $DIR/diagnostic-derive.rs:92:1

94 LL | #[diag(no_crate_example, code = E0123, slug = "foo")]
95    |                                        ^^^^
96    |
-    = note: only the `code` parameter is valid after the slug
+    = note: only `code` or `msrv`are valid after the slug
98 
99 error: derive(Diagnostic): `#[suggestion = ...]` is not a valid attribute
100   --> $DIR/diagnostic-derive.rs:105:5


The actual stderr differed from the expected stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args session-diagnostic/diagnostic-derive.rs`

error: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui-fulldeps/session-diagnostic/diagnostic-derive" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0"
stdout: none
--- stderr -------------------------------
error: derive(Diagnostic): unsupported type attribute for diagnostic derive enum
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:47:1
   |
LL | #[diag(no_crate_example, code = E0123)]
   | ^

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:50:5
   |
LL |     Foo,
   |     ^^^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:52:5
   |
LL |     Bar,
   |     ^^^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): `#[nonsense(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:63:1
   |
LL | #[nonsense(no_crate_example, code = E0123)]
   | ^

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:63:1
   |
LL | #[nonsense(no_crate_example, code = E0123)]
   | ^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:70:1
   |
LL | #[diag(code = E0123)]
   | ^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): diagnostic slug must be the first argument
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:80:16
   |
LL | #[diag(nonsense("foo"), code = E0123, slug = "foo")]
   |                ^

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:80:1
   |
LL | #[diag(nonsense("foo"), code = E0123, slug = "foo")]
   | ^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): unknown argument
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:86:8
   |
LL | #[diag(nonsense = "...", code = E0123, slug = "foo")]
   |        ^^^^^^^^
   |
   = note: only `code` or `msrv`are valid after the slug

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:86:1
   |
LL | #[diag(nonsense = "...", code = E0123, slug = "foo")]
   | ^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): unknown argument
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:92:8
   |
LL | #[diag(nonsense = 4, code = E0123, slug = "foo")]
   |        ^^^^^^^^
   |
   = note: only `code` or `msrv`are valid after the slug

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:92:1
   |
LL | #[diag(nonsense = 4, code = E0123, slug = "foo")]
   | ^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): unknown argument
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:98:40
   |
LL | #[diag(no_crate_example, code = E0123, slug = "foo")]
   |                                        ^^^^
   |
   = note: only `code` or `msrv`are valid after the slug

error: derive(Diagnostic): `#[suggestion = ...]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:105:5
   |
LL |     #[suggestion = "bar"]
   |     ^

---

error: derive(Diagnostic): attribute specified multiple times
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:118:40
   |
LL | #[diag(no_crate_example, code = E0123, code = E0456)]
   |                                        ^^^^
   |
note: previously specified here
  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:118:26
   |
LL | #[diag(no_crate_example, code = E0123, code = E0456)]
   |                          ^^^^

error: derive(Diagnostic): diagnostic slug must be the first argument
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:123:43
   |
LL | #[diag(no_crate_example, no_crate::example, code = E0123)]
   |                                           ^

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:128:1
   |
LL | struct KindNotProvided {} //~ ERROR diagnostic slug not specified
   | ^^^^^^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:131:1
   |
LL | #[diag(code = E0123)]
   | ^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): the `#[primary_span]` attribute can only be applied to fields of type `Span` or `MultiSpan`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:142:5
   |
LL |     #[primary_span]
   |     ^

error: derive(Diagnostic): `#[nonsense]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:150:5
   |
LL |     #[nonsense]
   |     ^

error: derive(Diagnostic): the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:167:5
   |
LL |     #[label(no_crate_label)]
   |     ^

error: derive(Diagnostic): `name` doesn't refer to a field on this type
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:175:46
   |
LL |     #[suggestion(no_crate_suggestion, code = "{name}")]
   |                                              ^^^^^^^^

error: invalid format string: expected `}` but string was terminated
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:180:10
   |
LL | #[derive(Diagnostic)]
   |          ^^^^^^^^^^ expected `}` in format string
   |
   = note: if you intended to print `{`, you can escape it using `{{`
   = note: this error originates in the derive macro `Diagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)

error: invalid format string: unmatched `}` found
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:190:10
   |
LL | #[derive(Diagnostic)]
   |          ^^^^^^^^^^ unmatched `}` in format string
   |
   = note: if you intended to print `}`, you can escape it using `}}`
   = note: this error originates in the derive macro `Diagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)

error: derive(Diagnostic): the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:210:5
   |
LL |     #[label(no_crate_label)]
   |     ^

error: derive(Diagnostic): suggestion without `code = "..."`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:229:5
   |
LL |     #[suggestion(no_crate_suggestion)]
   |     ^

---
   |                  ^^^^^^^^
   |
   = help: only `no_span`, `style`, `code` and `applicability` are valid nested attributes

error: derive(Diagnostic): suggestion without `code = "..."`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:237:5
   |
LL |     #[suggestion(nonsense = "bar")]
   |     ^

error: derive(Diagnostic): invalid nested attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:246:18
   |
LL |     #[suggestion(msg = "bar")]
   |                  ^^^
   |
   = help: only `no_span`, `style`, `code` and `applicability` are valid nested attributes

error: derive(Diagnostic): suggestion without `code = "..."`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:246:5
   |
LL |     #[suggestion(msg = "bar")]
   |     ^

error: derive(Diagnostic): wrong field type for suggestion
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:269:5
   |
LL |     #[suggestion(no_crate_suggestion, code = "This is suggested code")]
   |     ^
   |
   = help: `#[suggestion(...)]` should be applied to fields of type `Span` or `(Span, Applicability)`

error: derive(Diagnostic): attribute specified multiple times
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:285:24
   |
LL |     suggestion: (Span, Span, Applicability),
---
   |
LL |     suggestion: (Applicability, Applicability, Span),
   |                  ^^^^^^^^^^^^^

error: derive(Diagnostic): `#[label = ...]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:300:5
   |
LL |     #[label = "bar"]
   |     ^

error: derive(Diagnostic): attribute specified multiple times
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:451:5
   |
LL |     #[suggestion(no_crate_suggestion, code = "...", applicability = "maybe-incorrect")]
   |     ^
   |
note: previously specified here
  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:453:24
   |
LL |     suggestion: (Span, Applicability),
   |                        ^^^^^^^^^^^^^

error: derive(Diagnostic): invalid applicability
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:459:69
   |
LL |     #[suggestion(no_crate_suggestion, code = "...", applicability = "batman")]
   |                                                                     ^^^^^^^^

error: derive(Diagnostic): the `#[help(...)]` attribute can only be applied to fields of type `Span`, `MultiSpan`, `bool` or `()`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:526:5
   |
LL |     #[help(no_crate_help)]
   |     ^

error: derive(Diagnostic): a diagnostic slug must be the first argument to the attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:535:32
   |
LL |     #[label(no_crate_label, foo)]
   |                                ^

error: derive(Diagnostic): only `no_span` is a valid nested attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:543:29
   |
LL |     #[label(no_crate_label, foo = "...")]
   |                             ^^^

error: derive(Diagnostic): only `no_span` is a valid nested attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:551:29
   |
LL |     #[label(no_crate_label, foo("..."))]
   |                             ^^^

error: derive(Diagnostic): `#[primary_span]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:563:5
   |
LL |     #[primary_span]
   |     ^
   |
   = help: the `primary_span` field attribute is not valid for lint diagnostics

error: derive(Diagnostic): `#[error(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:583:1
   |
LL | #[error(no_crate_example, code = E0123)]
   | ^

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:583:1
   |
LL | #[error(no_crate_example, code = E0123)]
   | ^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): `#[warn_(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:590:1
   |
LL | #[warn_(no_crate_example, code = E0123)]
   | ^

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:590:1
   |
LL | #[warn_(no_crate_example, code = E0123)]
   | ^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): `#[lint(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:597:1
   |
LL | #[lint(no_crate_example, code = E0123)]
   | ^

error: derive(Diagnostic): diagnostic slug not specified
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:597:1
   |
LL | #[lint(no_crate_example, code = E0123)]
   | ^
   |
   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`

error: derive(Diagnostic): `#[lint(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:604:1
   |
LL | #[lint(no_crate_example, code = E0123)]
   | ^

---

error: derive(Diagnostic): attribute specified multiple times
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:613:53
   |
LL |     #[suggestion(no_crate_suggestion, code = "...", code = ",,,")]
   |                                                     ^^^^
   |
note: previously specified here
  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:613:39
   |
LL |     #[suggestion(no_crate_suggestion, code = "...", code = ",,,")]
   |                                       ^^^^

error: derive(Diagnostic): wrong types for suggestion
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:622:24
   |
LL |     suggestion: (Span, usize),
   |                        ^^^^^
   |
   = help: `#[suggestion(...)]` on a tuple field must be applied to fields of type `(Span, Applicability)`

error: derive(Diagnostic): wrong types for suggestion
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:630:17
   |
LL |     suggestion: (Span,),
   |                 ^^^^^^^
   |
   = help: `#[suggestion(...)]` on a tuple field must be applied to fields of type `(Span, Applicability)`

error: derive(Diagnostic): suggestion without `code = "..."`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:637:5
   |
LL |     #[suggestion(no_crate_suggestion)]
   |     ^

error: derive(Diagnostic): `#[multipart_suggestion(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:644:1
   |
LL | #[multipart_suggestion(no_crate_suggestion)]
   | ^
   |
   = help: consider creating a `Subdiagnostic` instead

error: derive(Diagnostic): `#[multipart_suggestion(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:647:1
   |
LL | #[multipart_suggestion()]
   | ^
   |
   = help: consider creating a `Subdiagnostic` instead

error: derive(Diagnostic): `#[multipart_suggestion(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:651:5
   |
LL |     #[multipart_suggestion(no_crate_suggestion)]
   |     ^
   |
   = help: consider creating a `Subdiagnostic` instead

error: derive(Diagnostic): `#[suggestion(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:659:1
   |
LL | #[suggestion(no_crate_suggestion, code = "...")]
   | ^
   |
   = help: `#[label]` and `#[suggestion]` can only be applied to fields

error: derive(Diagnostic): `#[label]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:668:1
   |
LL | #[label]
   | ^
   |
   = help: `#[label]` and `#[suggestion]` can only be applied to fields

error: derive(Diagnostic): `#[subdiagnostic(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:702:5
   |
LL |     #[subdiagnostic(bad)]
   |     ^

error: derive(Diagnostic): `#[subdiagnostic = ...]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:710:5
   |
LL |     #[subdiagnostic = "bad"]
   |     ^

error: derive(Diagnostic): `#[subdiagnostic(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:718:5
   |
LL |     #[subdiagnostic(bad, bad)]
   |     ^

error: derive(Diagnostic): `#[subdiagnostic(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:726:5
   |
LL |     #[subdiagnostic("bad")]
   |     ^

error: derive(Diagnostic): `#[subdiagnostic(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:734:5
   |
LL |     #[subdiagnostic(eager)]
   |     ^

error: derive(Diagnostic): `#[subdiagnostic(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:742:5
   |
LL |     #[subdiagnostic(eager)]
   |     ^

error: derive(Diagnostic): `#[subdiagnostic(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:763:5
   |
LL |     #[subdiagnostic(eager)]
   |     ^

error: derive(Diagnostic): expected at least one string literal for `code(...)`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:794:23
   |
LL |     #[suggestion(code())]
   |                       ^

error: derive(Diagnostic): `code(...)` must contain only string literals
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:802:23
   |
LL |     #[suggestion(code(foo))]
   |                       ^^^

error: derive(Diagnostic): `#[suggestion(...)]` is not a valid attribute
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:826:5
   |
LL |     #[suggestion(no_crate_suggestion, code = "")]
   |     ^
   |
   = note: `#[suggestion(...)]` applied to `Vec` field is ambiguous
   = help: to show a suggestion consisting of multiple parts, use a `Subdiagnostic` annotated with `#[multipart_suggestion(...)]`
   = help: to show a variable set of suggestions, use a `Vec` of `Subdiagnostic`s annotated with `#[suggestion(...)]`

error[E0433]: failed to resolve: you might be missing crate `core`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:58:8
   |
LL | #[diag = "E0123"]
   |        ^ you might be missing crate `core`

error[E0433]: failed to resolve: you might be missing crate `core`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:802:23
   |
LL |     #[suggestion(code(foo))]
   |                       ^^^ you might be missing crate `core`

error[E0433]: failed to resolve: you might be missing crate `core`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:811:25
   |
LL |     #[suggestion(code = 3)]
   |                         ^ you might be missing crate `core`

error: cannot find attribute `nonsense` in this scope
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:63:3
   |
LL | #[nonsense(no_crate_example, code = E0123)]
   |   ^^^^^^^^

error: cannot find attribute `nonsense` in this scope
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:150:7
   |
LL |     #[nonsense]
   |       ^^^^^^^^

error: cannot find attribute `error` in this scope
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:583:3
   |
LL | #[error(no_crate_example, code = E0123)]
   |   ^^^^^
   |
help: `error` is an attribute that can be used by the derive macro `Error`, you might be missing a `derive` attribute
   |
LL + #[derive(Error)]
LL | struct ErrorAttribute {}
   |

error: cannot find attribute `warn_` in this scope
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:590:3
   |
LL | #[warn_(no_crate_example, code = E0123)]
   |   ^^^^^
   |
help: a built-in attribute with a similar name exists
   |
LL - #[warn_(no_crate_example, code = E0123)]
LL + #[warn(no_crate_example, code = E0123)]
   |

error: cannot find attribute `lint` in this scope
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:597:3
   |
LL | #[lint(no_crate_example, code = E0123)]
   |   ^^^^
   |
help: a built-in attribute with a similar name exists
   |
LL - #[lint(no_crate_example, code = E0123)]
LL + #[link(no_crate_example, code = E0123)]
   |

error: cannot find attribute `lint` in this scope
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:604:3
   |
LL | #[lint(no_crate_example, code = E0123)]
   |   ^^^^
   |
help: a built-in attribute with a similar name exists
   |
LL - #[lint(no_crate_example, code = E0123)]
LL + #[link(no_crate_example, code = E0123)]
   |

error: cannot find attribute `multipart_suggestion` in this scope
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:644:3
   |
---

error[E0425]: cannot find value `nonsense` in module `crate::fluent_generated`
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:75:8
   |
LL | #[diag(nonsense, code = E0123)]
   |        ^^^^^^^^ not found in `crate::fluent_generated`

error[E0425]: cannot find value `__code_34` in this scope
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:808:10
   |
LL | #[derive(Diagnostic)] //~ ERROR cannot find value `__code_34` in this scope
   |          ^^^^^^^^^^ not found in this scope
   |
   = note: this error originates in the derive macro `Diagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `Hello: IntoDiagArg` is not satisfied
##[error]  --> /checkout/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs:349:12
   |
LL | #[derive(Diagnostic)]
   |          ---------- required by a bound introduced by this call
...
---
             AllocRange
             Backtrace
             Binder<I, T>
           and 75 others
note: required by a bound in `Diag::<'a, G>::arg`
  --> /rustc/FAKE_PREFIX/compiler/rustc_errors/src/diagnostic.rs:1332:4
   = note: this error originates in the macro `with_fn` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 85 previous errors

[RalfJung]

Adds an optional msrv field to DiagCtxtInner, parsed from CARGO_PKG_RUST_VERSION if present

That's an odd way to pass information from cargo to rustc. Usually we use command-line flags for that. Is there any precedent for rustc parsing a CARGO_* env var?

[mati865]

@rustbot reroll

I don't have experience with lint system.

[clubby789]

There's

rust/compiler/rustc_metadata/src/creader.rs

Lines 1275 to 1276 in f520900

	if name.as_str() == "wasm_bindgen" {
	let major = env::var("CARGO_PKG_VERSION_MAJOR")

as well as some Fluent translation infrastructure that use it.

If an --msrv flag or similar is preferred, I can open an MCP for that.

[RalfJung]

There's [...] as well as some Fluent translation infrastructure that use it.

Those are ad-hoc workarounds and largely only affect diagnostics. We can remove it any time, it's not part of the stable API of rustc.

(The use in compiler/rustc_fluent_macro/src/fluent.rs is a proc macro used in the compiler. So this happens at compiler build time, not at compiler run time.)

If an --msrv flag or similar is preferred, I can open an MCP for that.

I think that would be much more in line with the existing interface of rustc, yes. (This IMO needs an MCP either way since it's a new API no matter which shape it takes.)

[clubby789]

MCP: rust-lang/compiler-team#950