Auto merge of #67953 - cjgillot:split_infer, r=Zoxc

Split librustc::{traits,infer} to a separate crate rustc_infer

This is still very much work in progress.
Three functions are between dimensions (at the end of `rustc::traits`), waiting for some dependency breaking scheme.
Please tell me if the approach seems sound, and how you would like to split this PR up.

The formatting is deliberately off, to ease rebasing.

cc #65031

Author: bors

Cargo.lock

@@ -3111,8 +3111,6 @@ dependencies = [
  "bitflags",
  "byteorder",
  "chalk-engine",
- "fmt_macros",
- "graphviz",
  "jobserver",
  "log",
  "measureme",
@@ -3776,6 +3774,28 @@ dependencies = [
  "smallvec 1.0.0",
 ]
 
+[[package]]
+name = "rustc_infer"
+version = "0.0.0"
+dependencies = [
+ "fmt_macros",
+ "graphviz",
+ "log",
+ "rustc",
+ "rustc_attr",
+ "rustc_data_structures",
+ "rustc_error_codes",
+ "rustc_errors",
+ "rustc_hir",
+ "rustc_index",
+ "rustc_macros",
+ "rustc_session",
+ "rustc_span",
+ "rustc_target",
+ "smallvec 1.0.0",
+ "syntax",
+]
+
 [[package]]
 name = "rustc_interface"
 version = "0.0.0"
@@ -3796,6 +3816,7 @@ dependencies = [
  "rustc_expand",
  "rustc_hir",
  "rustc_incremental",
+ "rustc_infer",
  "rustc_lint",
  "rustc_metadata",
  "rustc_mir",
@@ -3838,6 +3859,7 @@ dependencies = [
  "rustc_feature",
  "rustc_hir",
  "rustc_index",
+ "rustc_infer",
  "rustc_session",
  "rustc_span",
  "rustc_target",
@@ -3907,6 +3929,7 @@ dependencies = [
  "rustc_errors",
  "rustc_hir",
  "rustc_index",
+ "rustc_infer",
  "rustc_lexer",
  "rustc_macros",
  "rustc_span",
@@ -3929,6 +3952,7 @@ dependencies = [
  "rustc_errors",
  "rustc_hir",
  "rustc_index",
+ "rustc_infer",
  "rustc_macros",
  "rustc_session",
  "rustc_span",
@@ -3969,6 +3993,7 @@ dependencies = [
  "rustc_feature",
  "rustc_hir",
  "rustc_index",
+ "rustc_infer",
  "rustc_session",
  "rustc_span",
  "rustc_target",
@@ -4019,6 +4044,7 @@ dependencies = [
  "rustc_expand",
  "rustc_feature",
  "rustc_hir",
+ "rustc_infer",
  "rustc_metadata",
  "rustc_session",
  "rustc_span",
@@ -4108,6 +4134,7 @@ dependencies = [
  "rustc",
  "rustc_data_structures",
  "rustc_hir",
+ "rustc_infer",
  "rustc_macros",
  "rustc_span",
  "rustc_target",
@@ -4123,6 +4150,7 @@ dependencies = [
  "rustc",
  "rustc_data_structures",
  "rustc_hir",
+ "rustc_infer",
  "rustc_span",
  "rustc_target",
 ]
@@ -4139,6 +4167,7 @@ dependencies = [
  "rustc_errors",
  "rustc_hir",
  "rustc_index",
+ "rustc_infer",
  "rustc_span",
  "rustc_target",
  "smallvec 1.0.0",

src/librustc/Cargo.toml

@@ -12,8 +12,6 @@ doctest = false
 [dependencies]
 arena = { path = "../libarena" }
 bitflags = "1.2.1"
-fmt_macros = { path = "../libfmt_macros" }
-graphviz = { path = "../libgraphviz" }
 jobserver = "0.1"
 scoped-tls = "1.0"
 log = { version = "0.4", features = ["release_max_level_info", "std"] }

src/librustc/arena.rs

@@ -51,19 +51,19 @@ macro_rules! arena_types {
             [] dropck_outlives:
                 rustc::infer::canonical::Canonical<'tcx,
                     rustc::infer::canonical::QueryResponse<'tcx,
-                        rustc::traits::query::dropck_outlives::DropckOutlivesResult<'tcx>
+                        rustc::traits::query::DropckOutlivesResult<'tcx>
                     >
                 >,
             [] normalize_projection_ty:
                 rustc::infer::canonical::Canonical<'tcx,
                     rustc::infer::canonical::QueryResponse<'tcx,
-                        rustc::traits::query::normalize::NormalizationResult<'tcx>
+                        rustc::traits::query::NormalizationResult<'tcx>
                     >
                 >,
             [] implied_outlives_bounds:
                 rustc::infer::canonical::Canonical<'tcx,
                     rustc::infer::canonical::QueryResponse<'tcx,
-                        Vec<rustc::traits::query::outlives_bounds::OutlivesBound<'tcx>>
+                        Vec<rustc::traits::query::OutlivesBound<'tcx>>
                     >
                 >,
             [] type_op_subtype:

src/librustc/infer/types/canonical.rs renamed to src/librustc/infer/canonical.rs

@@ -21,7 +21,7 @@
 //!
 //! [c]: https://rust-lang.github.io/rustc-guide/traits/canonicalization.html
 
-use crate::infer::region_constraints::MemberConstraint;
+use crate::infer::MemberConstraint;
 use crate::ty::subst::GenericArg;
 use crate::ty::{self, BoundVar, List, Region, TyCtxt};
 use rustc_index::vec::IndexVec;