Rollup merge of #145390 - joshtriplett:rustc-diag-value-earlier, r=lcnr

Shorten some dependency chains in the compiler

(I recommend reviewing this commit by commit.)

One of the long dependency chains in the compiler is:
- Many things depend on `rustc_errors`.
- `rustc_errors` depended on many things prior to this PR, including `rustc_target`, `rustc_type_ir`, `rustc_hir`, and `rustc_lint_defs`.
- `rustc_lint_defs` depended on `rustc_hir` prior to this PR.
- `rustc_hir` depends on `rustc_target`.
- `rustc_target` is large and takes a while.

This PR breaks that chain, through a few steps:
- The `IntoDiagArgs` trait, from `rustc_errors`, moves earlier in the dependency chain. This allows `rustc_errors` to stop depending on a pile of crates just to implement `IntoDiagArgs` for their types.
- Split `rustc_hir_id` out of `rustc_hir`, so crates that just need `HirId` and similar don't depend on all of `rust_hir` (and thus `rustc_target`).
- Make `rustc_lint_defs` stop depending on `rustc_hir`.

1 files changed, 13 insertions, 0 deletions

diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index 2aa8ab5d317..399770022b2 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -50,6 +50,7 @@ use rustc_abi::{
     Align, CanonAbi, Endian, ExternAbi, Integer, Size, TargetDataLayout, TargetDataLayoutErrors,
 };
 use rustc_data_structures::fx::{FxHashSet, FxIndexSet};
+use rustc_error_messages::{DiagArgValue, IntoDiagArg, into_diag_arg_using_display};
 use rustc_fs_util::try_canonicalize;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
@@ -875,6 +876,12 @@ impl FromStr for PanicStrategy {
 
 crate::json::serde_deserialize_from_str!(PanicStrategy);
 
+impl IntoDiagArg for PanicStrategy {
+    fn into_diag_arg(self, _: &mut Option<std::path::PathBuf>) -> DiagArgValue {
+        DiagArgValue::Str(Cow::Owned(self.desc().to_string()))
+    }
+}
+
 impl ToJson for PanicStrategy {
     fn to_json(&self) -> Json {
         match *self {
@@ -1518,6 +1525,8 @@ impl fmt::Display for SplitDebuginfo {
     }
 }
 
+into_diag_arg_using_display!(SplitDebuginfo);
+
 #[derive(Clone, Debug, PartialEq, Eq, serde_derive::Deserialize)]
 #[serde(tag = "kind")]
 #[serde(rename_all = "kebab-case")]
@@ -1795,6 +1804,8 @@ impl fmt::Display for StackProtector {
     }
 }
 
+into_diag_arg_using_display!(StackProtector);
+
 #[derive(PartialEq, Clone, Debug)]
 pub enum BinaryFormat {
     Coff,
@@ -3806,3 +3817,5 @@ impl fmt::Display for TargetTuple {
         write!(f, "{}", self.debug_tuple())
     }
 }
+
+into_diag_arg_using_display!(&TargetTuple);