Specify rust lints for `compiler/` crates via Cargo.

By naming them in `[workspace.lints.rust]` in the top-level
`Cargo.toml`, and then making all `compiler/` crates inherit them with
`[lints] workspace = true`. (I omitted `rustc_codegen_{cranelift,gcc}`,
because they're a bit different.)

The advantages of this over the current approach:
- It uses a standard Cargo feature, rather than special handling in
  bootstrap. So, easier to understand, and less likely to get
  accidentally broken in the future.
- It works for proc macro crates.

It's a shame it doesn't work for rustc-specific lints, as the comments
explain.

74 files changed, 237 insertions, 4 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 20a43aaaeeb..4e952ccfc73 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -63,6 +63,19 @@ exclude = [
   "src/tools/x",
 ]
 
+# These lints are applied to many crates in the workspace. In practice, this is
+# all crates under `compiler/`.
+#
+# NOTE: rustc-specific lints (e.g. `rustc::internal`) aren't supported by
+# Cargo. (Support for them is possibly blocked by #44690 (attributes for
+# tools).) Those lints are instead specified for `compiler/` crates in
+# `src/bootstrap/src/core/builder/cargo.rs`.
+[workspace.lints.rust]
+# FIXME(edition_2024): Change this to `-Wrust_2024_idioms` when all of the
+# individual lints are satisfied.
+keyword_idents_2024 = "warn"
+unsafe_op_in_unsafe_fn = "warn"
+
 [profile.release.package.rustc-rayon-core]
 # The rustc fork of Rayon has deadlock detection code which intermittently
 # causes overflows in the CI (see https://github.com/rust-lang/rust/issues/90227)
diff --git a/compiler/rustc/Cargo.toml b/compiler/rustc/Cargo.toml
index f4caa3ef769..7af0b34d2da 100644
--- a/compiler/rustc/Cargo.toml
+++ b/compiler/rustc/Cargo.toml
@@ -32,3 +32,6 @@ llvm = ['rustc_driver_impl/llvm']
 max_level_info = ['rustc_driver_impl/max_level_info']
 rustc_randomized_layouts = ['rustc_driver_impl/rustc_randomized_layouts']
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_abi/Cargo.toml b/compiler/rustc_abi/Cargo.toml
index 86dc84e2016..4713b3474bd 100644
--- a/compiler/rustc_abi/Cargo.toml
+++ b/compiler/rustc_abi/Cargo.toml
@@ -31,3 +31,6 @@ nightly = [
 ]
 randomize = ["dep:rand", "dep:rand_xoshiro", "nightly"]
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_arena/Cargo.toml b/compiler/rustc_arena/Cargo.toml
index bbcd8ea6d38..1a600f0ee3f 100644
--- a/compiler/rustc_arena/Cargo.toml
+++ b/compiler/rustc_arena/Cargo.toml
@@ -7,3 +7,6 @@ edition = "2024"
 # tidy-alphabetical-start
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_ast/Cargo.toml b/compiler/rustc_ast/Cargo.toml
index 902287d0328..259b51689e4 100644
--- a/compiler/rustc_ast/Cargo.toml
+++ b/compiler/rustc_ast/Cargo.toml
@@ -18,3 +18,6 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_ast_ir/Cargo.toml b/compiler/rustc_ast_ir/Cargo.toml
index f54e9687d8c..668c45438d6 100644
--- a/compiler/rustc_ast_ir/Cargo.toml
+++ b/compiler/rustc_ast_ir/Cargo.toml
@@ -19,3 +19,6 @@ nightly = [
     "dep:rustc_macros",
     "dep:rustc_span",
 ]
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_ast_lowering/Cargo.toml b/compiler/rustc_ast_lowering/Cargo.toml
index 2ec4f4b0555..358963c7997 100644
--- a/compiler/rustc_ast_lowering/Cargo.toml
+++ b/compiler/rustc_ast_lowering/Cargo.toml
@@ -28,3 +28,6 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_ast_passes/Cargo.toml b/compiler/rustc_ast_passes/Cargo.toml
index c738cb2aa2f..5966308a262 100644
--- a/compiler/rustc_ast_passes/Cargo.toml
+++ b/compiler/rustc_ast_passes/Cargo.toml
@@ -20,3 +20,6 @@ rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 thin-vec = "0.2.12"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_ast_pretty/Cargo.toml b/compiler/rustc_ast_pretty/Cargo.toml
index 2634dd1fdf9..b120bdc2f05 100644
--- a/compiler/rustc_ast_pretty/Cargo.toml
+++ b/compiler/rustc_ast_pretty/Cargo.toml
@@ -12,3 +12,6 @@ rustc_lexer = { path = "../rustc_lexer" }
 rustc_span = { path = "../rustc_span" }
 thin-vec = "0.2.12"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_attr_data_structures/Cargo.toml b/compiler/rustc_attr_data_structures/Cargo.toml
index b18923c337f..8fbc21f3ba2 100644
--- a/compiler/rustc_attr_data_structures/Cargo.toml
+++ b/compiler/rustc_attr_data_structures/Cargo.toml
@@ -14,3 +14,6 @@ rustc_serialize = {path = "../rustc_serialize"}
 rustc_span = {path = "../rustc_span"}
 thin-vec = "0.2.12"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_attr_parsing/Cargo.toml b/compiler/rustc_attr_parsing/Cargo.toml
index c335eeb5f71..39f4010f303 100644
--- a/compiler/rustc_attr_parsing/Cargo.toml
+++ b/compiler/rustc_attr_parsing/Cargo.toml
@@ -21,3 +21,6 @@ rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 thin-vec = "0.2.12"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_baked_icu_data/Cargo.toml b/compiler/rustc_baked_icu_data/Cargo.toml
index cb0e145386b..1480b59f1e0 100644
--- a/compiler/rustc_baked_icu_data/Cargo.toml
+++ b/compiler/rustc_baked_icu_data/Cargo.toml
@@ -11,3 +11,6 @@ icu_locid_transform = "1.3.2"
 icu_provider = { version = "1.2", features = ["sync"] }
 zerovec = "0.10.0"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_borrowck/Cargo.toml b/compiler/rustc_borrowck/Cargo.toml
index 9e7d55180a2..15338eeb37a 100644
--- a/compiler/rustc_borrowck/Cargo.toml
+++ b/compiler/rustc_borrowck/Cargo.toml
@@ -27,3 +27,6 @@ rustc_traits = { path = "../rustc_traits" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_builtin_macros/Cargo.toml b/compiler/rustc_builtin_macros/Cargo.toml
index 1289d21308b..da3572eebee 100644
--- a/compiler/rustc_builtin_macros/Cargo.toml
+++ b/compiler/rustc_builtin_macros/Cargo.toml
@@ -30,3 +30,6 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_codegen_llvm/Cargo.toml b/compiler/rustc_codegen_llvm/Cargo.toml
index d3ce7c5a113..1741c3bacc7 100644
--- a/compiler/rustc_codegen_llvm/Cargo.toml
+++ b/compiler/rustc_codegen_llvm/Cargo.toml
@@ -43,3 +43,6 @@ serde_json = "1"
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_codegen_ssa/Cargo.toml b/compiler/rustc_codegen_ssa/Cargo.toml
index 1346efcb87c..c00be0e9926 100644
--- a/compiler/rustc_codegen_ssa/Cargo.toml
+++ b/compiler/rustc_codegen_ssa/Cargo.toml
@@ -63,3 +63,6 @@ features = ["read_core", "elf", "macho", "pe", "xcoff", "unaligned", "archive",
 [target.'cfg(windows)'.dependencies.windows]
 version = "0.59.0"
 features = ["Win32_Globalization"]
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_const_eval/Cargo.toml b/compiler/rustc_const_eval/Cargo.toml
index a0cc2c65e6e..d76238a3992 100644
--- a/compiler/rustc_const_eval/Cargo.toml
+++ b/compiler/rustc_const_eval/Cargo.toml
@@ -26,3 +26,6 @@ rustc_trait_selection = { path = "../rustc_trait_selection" }
 rustc_type_ir = { path = "../rustc_type_ir" }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_data_structures/Cargo.toml b/compiler/rustc_data_structures/Cargo.toml
index bdf5494f210..b364ab0dde4 100644
--- a/compiler/rustc_data_structures/Cargo.toml
+++ b/compiler/rustc_data_structures/Cargo.toml
@@ -54,3 +54,6 @@ memmap2 = "0.2.1"
 
 [target.'cfg(not(target_has_atomic = "64"))'.dependencies]
 portable-atomic = "1.5.1"
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_driver/Cargo.toml b/compiler/rustc_driver/Cargo.toml
index e3ee8351295..d27895a5e7a 100644
--- a/compiler/rustc_driver/Cargo.toml
+++ b/compiler/rustc_driver/Cargo.toml
@@ -10,3 +10,6 @@ crate-type = ["dylib"]
 # tidy-alphabetical-start
 rustc_driver_impl = { path = "../rustc_driver_impl" }
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_driver_impl/Cargo.toml b/compiler/rustc_driver_impl/Cargo.toml
index 8593d1faba2..4469fa4e1f3 100644
--- a/compiler/rustc_driver_impl/Cargo.toml
+++ b/compiler/rustc_driver_impl/Cargo.toml
@@ -79,3 +79,6 @@ rustc_randomized_layouts = [
     'rustc_middle/rustc_randomized_layouts'
 ]
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_error_codes/Cargo.toml b/compiler/rustc_error_codes/Cargo.toml
index 55b4e899051..d89e4526016 100644
--- a/compiler/rustc_error_codes/Cargo.toml
+++ b/compiler/rustc_error_codes/Cargo.toml
@@ -6,3 +6,6 @@ edition = "2024"
 [dependencies]
 # tidy-alphabetical-start
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_error_messages/Cargo.toml b/compiler/rustc_error_messages/Cargo.toml
index 578af7fc51d..e9047ba16e5 100644
--- a/compiler/rustc_error_messages/Cargo.toml
+++ b/compiler/rustc_error_messages/Cargo.toml
@@ -19,3 +19,6 @@ rustc_span = { path = "../rustc_span" }
 tracing = "0.1"
 unic-langid = { version = "0.9.0", features = ["macros"] }
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_errors/Cargo.toml b/compiler/rustc_errors/Cargo.toml
index b11793c190a..fc39a726093 100644
--- a/compiler/rustc_errors/Cargo.toml
+++ b/compiler/rustc_errors/Cargo.toml
@@ -39,3 +39,6 @@ features = [
     "Win32_Security",
     "Win32_System_Threading",
 ]
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_expand/Cargo.toml b/compiler/rustc_expand/Cargo.toml
index 0ba139ea5cc..f051ea0c2ac 100644
--- a/compiler/rustc_expand/Cargo.toml
+++ b/compiler/rustc_expand/Cargo.toml
@@ -29,3 +29,6 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_feature/Cargo.toml b/compiler/rustc_feature/Cargo.toml
index a5ae06473cb..1aaace75404 100644
--- a/compiler/rustc_feature/Cargo.toml
+++ b/compiler/rustc_feature/Cargo.toml
@@ -10,3 +10,6 @@ rustc_span = { path = "../rustc_span" }
 serde = { version = "1.0.125", features = [ "derive" ] }
 serde_json = "1.0.59"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_fluent_macro/Cargo.toml b/compiler/rustc_fluent_macro/Cargo.toml
index ce76b2745ea..695e8b3fd5d 100644
--- a/compiler/rustc_fluent_macro/Cargo.toml
+++ b/compiler/rustc_fluent_macro/Cargo.toml
@@ -16,3 +16,6 @@ quote = "1"
 syn = { version = "2", features = ["full"] }
 unic-langid = { version = "0.9.0", features = ["macros"] }
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_fs_util/Cargo.toml b/compiler/rustc_fs_util/Cargo.toml
index baca3bc7d49..3518209ea5b 100644
--- a/compiler/rustc_fs_util/Cargo.toml
+++ b/compiler/rustc_fs_util/Cargo.toml
@@ -6,3 +6,6 @@ edition = "2024"
 [dependencies]
 # tidy-alphabetical-start
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_graphviz/Cargo.toml b/compiler/rustc_graphviz/Cargo.toml
index d84943760ba..2672a624eab 100644
--- a/compiler/rustc_graphviz/Cargo.toml
+++ b/compiler/rustc_graphviz/Cargo.toml
@@ -6,3 +6,6 @@ edition = "2024"
 [dependencies]
 # tidy-alphabetical-start
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_hashes/Cargo.toml b/compiler/rustc_hashes/Cargo.toml
index c7a273cff88..ff46696c4c0 100644
--- a/compiler/rustc_hashes/Cargo.toml
+++ b/compiler/rustc_hashes/Cargo.toml
@@ -7,3 +7,6 @@ edition = "2024"
 # tidy-alphabetical-start
 rustc-stable-hash = { version = "0.1.0" }
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_hir/Cargo.toml b/compiler/rustc_hir/Cargo.toml
index 7ca8539845a..e45c49cd7db 100644
--- a/compiler/rustc_hir/Cargo.toml
+++ b/compiler/rustc_hir/Cargo.toml
@@ -21,3 +21,6 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_hir_analysis/Cargo.toml b/compiler/rustc_hir_analysis/Cargo.toml
index 55a816a855a..99ced5ff0a9 100644
--- a/compiler/rustc_hir_analysis/Cargo.toml
+++ b/compiler/rustc_hir_analysis/Cargo.toml
@@ -32,3 +32,6 @@ rustc_type_ir = { path = "../rustc_type_ir" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_hir_pretty/Cargo.toml b/compiler/rustc_hir_pretty/Cargo.toml
index 86989d1e55b..ec95438b421 100644
--- a/compiler/rustc_hir_pretty/Cargo.toml
+++ b/compiler/rustc_hir_pretty/Cargo.toml
@@ -12,3 +12,6 @@ rustc_attr_parsing = { path = "../rustc_attr_parsing" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_span = { path = "../rustc_span" }
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_hir_typeck/Cargo.toml b/compiler/rustc_hir_typeck/Cargo.toml
index f1afb7b712d..1d6486fb7dc 100644
--- a/compiler/rustc_hir_typeck/Cargo.toml
+++ b/compiler/rustc_hir_typeck/Cargo.toml
@@ -27,3 +27,6 @@ rustc_type_ir = { path = "../rustc_type_ir" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_incremental/Cargo.toml b/compiler/rustc_incremental/Cargo.toml
index 4939bfb3a1c..754881309bf 100644
--- a/compiler/rustc_incremental/Cargo.toml
+++ b/compiler/rustc_incremental/Cargo.toml
@@ -22,3 +22,6 @@ rustc_span = { path = "../rustc_span" }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_index/Cargo.toml b/compiler/rustc_index/Cargo.toml
index 3d83a3c98da..ee6fe11f9a5 100644
--- a/compiler/rustc_index/Cargo.toml
+++ b/compiler/rustc_index/Cargo.toml
@@ -21,3 +21,6 @@ nightly = [
 ]
 rustc_randomized_layouts = []
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_index_macros/Cargo.toml b/compiler/rustc_index_macros/Cargo.toml
index 891e7ded619..de100bd0e2c 100644
--- a/compiler/rustc_index_macros/Cargo.toml
+++ b/compiler/rustc_index_macros/Cargo.toml
@@ -13,3 +13,6 @@ quote = "1"
 
 [features]
 nightly = []
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_infer/Cargo.toml b/compiler/rustc_infer/Cargo.toml
index 08c03614884..242886a9248 100644
--- a/compiler/rustc_infer/Cargo.toml
+++ b/compiler/rustc_infer/Cargo.toml
@@ -21,3 +21,6 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_interface/Cargo.toml b/compiler/rustc_interface/Cargo.toml
index 9c9660cf504..add8c0e20e6 100644
--- a/compiler/rustc_interface/Cargo.toml
+++ b/compiler/rustc_interface/Cargo.toml
@@ -56,3 +56,6 @@ tracing = "0.1"
 # tidy-alphabetical-start
 llvm = ['dep:rustc_codegen_llvm']
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_lexer/Cargo.toml b/compiler/rustc_lexer/Cargo.toml
index 448a50faf45..b9b16eebc54 100644
--- a/compiler/rustc_lexer/Cargo.toml
+++ b/compiler/rustc_lexer/Cargo.toml
@@ -24,3 +24,6 @@ features = ["emoji"]
 
 [dev-dependencies]
 expect-test = "1.4.0"
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_lint/Cargo.toml b/compiler/rustc_lint/Cargo.toml
index d6014f5006a..f6c10aa9744 100644
--- a/compiler/rustc_lint/Cargo.toml
+++ b/compiler/rustc_lint/Cargo.toml
@@ -28,3 +28,6 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 unicode-security = "0.1.0"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_lint_defs/Cargo.toml b/compiler/rustc_lint_defs/Cargo.toml
index 9ab350daf69..f9b45a00ec1 100644
--- a/compiler/rustc_lint_defs/Cargo.toml
+++ b/compiler/rustc_lint_defs/Cargo.toml
@@ -15,3 +15,6 @@ rustc_serialize = { path = "../rustc_serialize" }
 rustc_span = { path = "../rustc_span" }
 serde = { version = "1.0.125", features = ["derive"] }
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_llvm/Cargo.toml b/compiler/rustc_llvm/Cargo.toml
index 061562b2ec5..dcfaf9a0282 100644
--- a/compiler/rustc_llvm/Cargo.toml
+++ b/compiler/rustc_llvm/Cargo.toml
@@ -14,3 +14,6 @@ libc = "0.2.73"
 # pinned `cc` in `rustc_codegen_ssa` if you update `cc` here.
 cc = "=1.2.16"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_log/Cargo.toml b/compiler/rustc_log/Cargo.toml
index 30f6e9ba805..665ebd52f47 100644
--- a/compiler/rustc_log/Cargo.toml
+++ b/compiler/rustc_log/Cargo.toml
@@ -20,3 +20,6 @@ rustc_span = { path = "../rustc_span" }
 # tidy-alphabetical-start
 max_level_info = ['tracing/max_level_info']
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_macros/Cargo.toml b/compiler/rustc_macros/Cargo.toml
index f9d3b758359..b937f75e892 100644
--- a/compiler/rustc_macros/Cargo.toml
+++ b/compiler/rustc_macros/Cargo.toml
@@ -13,3 +13,6 @@ quote = "1"
 syn = { version = "2.0.9", features = ["full"] }
 synstructure = "0.13.0"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_metadata/Cargo.toml b/compiler/rustc_metadata/Cargo.toml
index a8821640f04..5fa3047d14e 100644
--- a/compiler/rustc_metadata/Cargo.toml
+++ b/compiler/rustc_metadata/Cargo.toml
@@ -31,3 +31,6 @@ rustc_type_ir = { path = "../rustc_type_ir" }
 tempfile = "3.2"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_middle/Cargo.toml b/compiler/rustc_middle/Cargo.toml
index aebd2181f31..63b648b770d 100644
--- a/compiler/rustc_middle/Cargo.toml
+++ b/compiler/rustc_middle/Cargo.toml
@@ -42,3 +42,6 @@ tracing = "0.1"
 # tidy-alphabetical-start
 rustc_randomized_layouts = []
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_mir_build/Cargo.toml b/compiler/rustc_mir_build/Cargo.toml
index d70d70a31a4..a29c0116266 100644
--- a/compiler/rustc_mir_build/Cargo.toml
+++ b/compiler/rustc_mir_build/Cargo.toml
@@ -28,3 +28,6 @@ rustc_span = { path = "../rustc_span" }
 rustc_trait_selection = { path = "../rustc_trait_selection" }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_mir_dataflow/Cargo.toml b/compiler/rustc_mir_dataflow/Cargo.toml
index 293bcbef21b..a171f9641bb 100644
--- a/compiler/rustc_mir_dataflow/Cargo.toml
+++ b/compiler/rustc_mir_dataflow/Cargo.toml
@@ -21,3 +21,6 @@ rustc_span = { path = "../rustc_span" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_mir_transform/Cargo.toml b/compiler/rustc_mir_transform/Cargo.toml
index fb8d0ac5e74..4dc91723f03 100644
--- a/compiler/rustc_mir_transform/Cargo.toml
+++ b/compiler/rustc_mir_transform/Cargo.toml
@@ -30,3 +30,6 @@ rustc_type_ir = { path = "../rustc_type_ir" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_monomorphize/Cargo.toml b/compiler/rustc_monomorphize/Cargo.toml
index 36b76d261de..51be8e55fa7 100644
--- a/compiler/rustc_monomorphize/Cargo.toml
+++ b/compiler/rustc_monomorphize/Cargo.toml
@@ -22,3 +22,6 @@ serde = "1"
 serde_json = "1"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_next_trait_solver/Cargo.toml b/compiler/rustc_next_trait_solver/Cargo.toml
index 63aa60f2f26..e119d23d41a 100644
--- a/compiler/rustc_next_trait_solver/Cargo.toml
+++ b/compiler/rustc_next_trait_solver/Cargo.toml
@@ -24,3 +24,6 @@ nightly = [
     "rustc_index/nightly",
     "rustc_type_ir/nightly",
 ]
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_parse/Cargo.toml b/compiler/rustc_parse/Cargo.toml
index c9dcab0c871..b78ac197dbb 100644
--- a/compiler/rustc_parse/Cargo.toml
+++ b/compiler/rustc_parse/Cargo.toml
@@ -26,3 +26,5 @@ unicode-width = "0.2.0"
 [dev-dependencies]
 termcolor = "1.2"
 
+[lints]
+workspace = true
diff --git a/compiler/rustc_parse_format/Cargo.toml b/compiler/rustc_parse_format/Cargo.toml
index a39cca716d2..a720903097a 100644
--- a/compiler/rustc_parse_format/Cargo.toml
+++ b/compiler/rustc_parse_format/Cargo.toml
@@ -8,3 +8,6 @@ edition = "2024"
 rustc_index = { path = "../rustc_index", default-features = false }
 rustc_lexer = { path = "../rustc_lexer" }
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_passes/Cargo.toml b/compiler/rustc_passes/Cargo.toml
index ba81ef3103b..4cd7fde6034 100644
--- a/compiler/rustc_passes/Cargo.toml
+++ b/compiler/rustc_passes/Cargo.toml
@@ -26,3 +26,6 @@ rustc_target = { path = "../rustc_target" }
 rustc_trait_selection = { path = "../rustc_trait_selection" }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_pattern_analysis/Cargo.toml b/compiler/rustc_pattern_analysis/Cargo.toml
index 40d549630ac..0624fe96cd9 100644
--- a/compiler/rustc_pattern_analysis/Cargo.toml
+++ b/compiler/rustc_pattern_analysis/Cargo.toml
@@ -43,3 +43,6 @@ rustc = [
     "smallvec/may_dangle",
     "rustc_index/nightly",
 ]
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_privacy/Cargo.toml b/compiler/rustc_privacy/Cargo.toml
index 242c67d732a..dc00ea8af43 100644
--- a/compiler/rustc_privacy/Cargo.toml
+++ b/compiler/rustc_privacy/Cargo.toml
@@ -18,3 +18,6 @@ rustc_span = { path = "../rustc_span" }
 rustc_ty_utils = { path = "../rustc_ty_utils" }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_query_impl/Cargo.toml b/compiler/rustc_query_impl/Cargo.toml
index c85156e059e..42f78448151 100644
--- a/compiler/rustc_query_impl/Cargo.toml
+++ b/compiler/rustc_query_impl/Cargo.toml
@@ -20,3 +20,6 @@ rustc_span = { path = "../rustc_span" }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_query_system/Cargo.toml b/compiler/rustc_query_system/Cargo.toml
index 3e8ccb51021..c34d1170f0e 100644
--- a/compiler/rustc_query_system/Cargo.toml
+++ b/compiler/rustc_query_system/Cargo.toml
@@ -25,3 +25,6 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_resolve/Cargo.toml b/compiler/rustc_resolve/Cargo.toml
index f4771f1af2c..8958a3ac304 100644
--- a/compiler/rustc_resolve/Cargo.toml
+++ b/compiler/rustc_resolve/Cargo.toml
@@ -28,3 +28,6 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_sanitizers/Cargo.toml b/compiler/rustc_sanitizers/Cargo.toml
index 900cd4243b1..e18ed121ca5 100644
--- a/compiler/rustc_sanitizers/Cargo.toml
+++ b/compiler/rustc_sanitizers/Cargo.toml
@@ -15,3 +15,6 @@ rustc_middle = { path = "../rustc_middle" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
 rustc_trait_selection = { path = "../rustc_trait_selection" }
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_serialize/Cargo.toml b/compiler/rustc_serialize/Cargo.toml
index 948242352e7..10bfe14abde 100644
--- a/compiler/rustc_serialize/Cargo.toml
+++ b/compiler/rustc_serialize/Cargo.toml
@@ -16,3 +16,6 @@ thin-vec = "0.2.12"
 rustc_macros = { path = "../rustc_macros" }
 tempfile = "3.2"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_session/Cargo.toml b/compiler/rustc_session/Cargo.toml
index a087725d34d..4b2b41ba845 100644
--- a/compiler/rustc_session/Cargo.toml
+++ b/compiler/rustc_session/Cargo.toml
@@ -37,3 +37,6 @@ features = [
     "Win32_Foundation",
     "Win32_System_LibraryLoader",
 ]
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_smir/Cargo.toml b/compiler/rustc_smir/Cargo.toml
index a11df9a9c9b..d14bff73b8b 100644
--- a/compiler/rustc_smir/Cargo.toml
+++ b/compiler/rustc_smir/Cargo.toml
@@ -18,3 +18,6 @@ scoped-tls = "1.0"
 stable_mir = {path = "../stable_mir" }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_span/Cargo.toml b/compiler/rustc_span/Cargo.toml
index 43a2d692577..a6f86151b81 100644
--- a/compiler/rustc_span/Cargo.toml
+++ b/compiler/rustc_span/Cargo.toml
@@ -22,3 +22,6 @@ sha2 = "0.10.1"
 tracing = "0.1"
 unicode-width = "0.2.0"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_symbol_mangling/Cargo.toml b/compiler/rustc_symbol_mangling/Cargo.toml
index 90ddf4c8a04..89fe7ef2e40 100644
--- a/compiler/rustc_symbol_mangling/Cargo.toml
+++ b/compiler/rustc_symbol_mangling/Cargo.toml
@@ -19,3 +19,6 @@ rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_target/Cargo.toml b/compiler/rustc_target/Cargo.toml
index 189b19b0286..6a0268cdee7 100644
--- a/compiler/rustc_target/Cargo.toml
+++ b/compiler/rustc_target/Cargo.toml
@@ -22,3 +22,6 @@ default-features = false
 features = ["elf", "macho"]
 version = "0.36.2"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_trait_selection/Cargo.toml b/compiler/rustc_trait_selection/Cargo.toml
index 1c61e23362a..5def437bd80 100644
--- a/compiler/rustc_trait_selection/Cargo.toml
+++ b/compiler/rustc_trait_selection/Cargo.toml
@@ -26,3 +26,6 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_traits/Cargo.toml b/compiler/rustc_traits/Cargo.toml
index 04aef4e7b9e..49bcaae8571 100644
--- a/compiler/rustc_traits/Cargo.toml
+++ b/compiler/rustc_traits/Cargo.toml
@@ -13,3 +13,6 @@ rustc_span = { path = "../rustc_span" }
 rustc_trait_selection = { path = "../rustc_trait_selection" }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_transmute/Cargo.toml b/compiler/rustc_transmute/Cargo.toml
index f0c783b3002..ae1beb10728 100644
--- a/compiler/rustc_transmute/Cargo.toml
+++ b/compiler/rustc_transmute/Cargo.toml
@@ -25,3 +25,6 @@ rustc = [
 # tidy-alphabetical-start
 itertools = "0.12"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_ty_utils/Cargo.toml b/compiler/rustc_ty_utils/Cargo.toml
index 4c7a57f2931..61acc12d0eb 100644
--- a/compiler/rustc_ty_utils/Cargo.toml
+++ b/compiler/rustc_ty_utils/Cargo.toml
@@ -23,3 +23,6 @@ rustc_trait_selection = { path = "../rustc_trait_selection" }
 rustc_type_ir = { path = "../rustc_type_ir" }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_type_ir/Cargo.toml b/compiler/rustc_type_ir/Cargo.toml
index 4adf7157926..0381797d7e9 100644
--- a/compiler/rustc_type_ir/Cargo.toml
+++ b/compiler/rustc_type_ir/Cargo.toml
@@ -33,3 +33,6 @@ nightly = [
     "rustc_index/nightly",
     "rustc_ast_ir/nightly",
 ]
+
+[lints]
+workspace = true
diff --git a/compiler/rustc_type_ir_macros/Cargo.toml b/compiler/rustc_type_ir_macros/Cargo.toml
index 15a55575099..a3fa4623855 100644
--- a/compiler/rustc_type_ir_macros/Cargo.toml
+++ b/compiler/rustc_type_ir_macros/Cargo.toml
@@ -13,3 +13,6 @@ quote = "1"
 syn = { version = "2.0.9", features = ["full"] }
 synstructure = "0.13.0"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true
diff --git a/compiler/stable_mir/Cargo.toml b/compiler/stable_mir/Cargo.toml
index d691a0e4f22..358a3915402 100644
--- a/compiler/stable_mir/Cargo.toml
+++ b/compiler/stable_mir/Cargo.toml
@@ -6,3 +6,6 @@ edition = "2024"
 [dependencies]
 scoped-tls = "1.0"
 serde = { version = "1.0.125", features = [ "derive" ] }
+
+[lints]
+workspace = true
diff --git a/src/bootstrap/src/core/builder/cargo.rs b/src/bootstrap/src/core/builder/cargo.rs
index d1d52d82eaa..18154007436 100644
--- a/src/bootstrap/src/core/builder/cargo.rs
+++ b/src/bootstrap/src/core/builder/cargo.rs
@@ -1072,12 +1072,17 @@ impl Builder<'_> {
         }
 
         if mode == Mode::Rustc {
+            // NOTE: rustc-specific lints are specified here. Normal rust lints
+            // are specified in the `[workspace.lints.rust]` section in the
+            // top-level `Cargo.toml`. If/when tool lints are supported by
+            // Cargo, these lints can be move to a `[workspace.lints.rustc]`
+            // section in the top-level `Cargo.toml`.
+            //
+            // NOTE: these flags are added to RUSTFLAGS, which is ignored when
+            // compiling proc macro crates such as `rustc_macros`,
+            // unfortunately.
             rustflags.arg("-Wrustc::internal");
             rustflags.arg("-Drustc::symbol_intern_string_literal");
-            // FIXME(edition_2024): Change this to `-Wrust_2024_idioms` when all
-            // of the individual lints are satisfied.
-            rustflags.arg("-Wkeyword_idents_2024");
-            rustflags.arg("-Wunsafe_op_in_unsafe_fn");
         }
 
         if self.config.rust_frame_pointers {