Auto merge of #12911 - epage:manifest-schema, r=weihanglo

refactor(toml): Pull out the schema

### What does this PR try to resolve?

On its own, this PR is a net negative for readability / complexity.  It moves all of the serde types related to manifest from `toml/mod.rs` to `toml/schema.rs`, leaving a lot of the functions and some trait implementations back in `toml/mod.rs` (some basic functions that made sense for the type on their own were also moved).

So why do this?  This is an ooch towards having the schema broken out into a separate package (#12801).  To do this, we need to
- Identify what all types need to be put in the package.  This refactor highlights the dependence on `RustVersion` and `PackageIdSpec`
- Highlights what functionality we need to find a new home for

Follow up PRs would
- Find better homes for the logic in `toml/mod.rs`, moving us away from having `impl schema::Type` blocks.
- Pull out a `src/cargo/util_semver` package to own `PartialVersion` (at least) as prep for making a `cargo-util-semver` package
- Move `RustVersion` to `manifest-toml/schema.rs`, deciding what functionality needs to move with the type
- Move or copy `PackageIdSpec` into `manfest-toml/schema.rs`, deciding what functionality remain in `core/` and what moves over
- Move `toml/schema.rs` to `src/cargo/util_schema`
- Actually make `cargo-util-semver` and `cargo-util-manifest-schema` packages

So why do this now? This is a big change!  By being incremental
- Reduce churn for me and others
- Be easier to review
- Collect feedback as we go on the whole plan to avoid more painful changes later

We *can* back this out if needed but the further we go, the more painful it will be.

### How should we test and review this PR?

### Additional information

Author: bors

src/bin/cargo/main.rs

@@ -4,7 +4,7 @@
 
 use cargo::util::network::http::http_handle;
 use cargo::util::network::http::needs_custom_http_transport;
-use cargo::util::toml::StringOrVec;
+use cargo::util::toml::schema::StringOrVec;
 use cargo::util::CliError;
 use cargo::util::{self, closest_msg, command_prelude, CargoResult, CliResult, Config};
 use cargo_util::{ProcessBuilder, ProcessError};

src/cargo/core/compiler/mod.rs

@@ -93,8 +93,8 @@ use crate::core::{Feature, PackageId, Target, Verbosity};
 use crate::util::errors::{CargoResult, VerboseError};
 use crate::util::interning::InternedString;
 use crate::util::machine_message::{self, Message};
-use crate::util::toml::TomlDebugInfo;
-use crate::util::toml::TomlTrimPaths;
+use crate::util::toml::schema::TomlDebugInfo;
+use crate::util::toml::schema::TomlTrimPaths;
 use crate::util::{add_path_args, internal, iter_join_onto, profile};
 use cargo_util::{paths, ProcessBuilder, ProcessError};
 use rustfix::diagnostics::Applicability;

src/cargo/core/features.rs

@@ -195,7 +195,7 @@ pub const SEE_CHANNELS: &str =
 /// [`LATEST_STABLE`]: Edition::LATEST_STABLE
 /// [this example]: https://github.com/rust-lang/cargo/blob/3ebb5f15a940810f250b68821149387af583a79e/src/doc/src/reference/unstable.md?plain=1#L1238-L1264
 /// [`is_stable`]: Edition::is_stable
-/// [`TomlManifest::to_real_manifest`]: crate::util::toml::TomlManifest::to_real_manifest
+/// [`TomlManifest::to_real_manifest`]: crate::util::toml::schema::TomlManifest::to_real_manifest
 /// [`features!`]: macro.features.html
 #[derive(Clone, Copy, Debug, Hash, PartialOrd, Ord, Eq, PartialEq, Serialize, Deserialize)]
 pub enum Edition {

src/cargo/core/manifest.rs

@@ -18,7 +18,7 @@ use crate::core::{Dependency, PackageId, PackageIdSpec, SourceId, Summary};
 use crate::core::{Edition, Feature, Features, WorkspaceConfig};
 use crate::util::errors::*;
 use crate::util::interning::InternedString;
-use crate::util::toml::{TomlManifest, TomlProfiles};
+use crate::util::toml::schema::{TomlManifest, TomlProfiles};
 use crate::util::{short_hash, Config, Filesystem, RustVersion};
 
 pub enum EitherManifest {

src/cargo/core/mod.rs

@@ -14,7 +14,7 @@ pub use self::workspace::{
     find_workspace_root, resolve_relative_path, MaybePackage, Workspace, WorkspaceConfig,
     WorkspaceRootConfig,
 };
-pub use crate::util::toml::InheritableFields;
+pub use crate::util::toml::schema::InheritableFields;
 
 pub mod compiler;
 pub mod dependency;

src/cargo/core/profiles.rs

@@ -27,9 +27,9 @@ use crate::core::resolver::features::FeaturesFor;
 use crate::core::Feature;
 use crate::core::{PackageId, PackageIdSpec, Resolve, Shell, Target, Workspace};
 use crate::util::interning::InternedString;
-use crate::util::toml::TomlTrimPaths;
-use crate::util::toml::TomlTrimPathsValue;
-use crate::util::toml::{
+use crate::util::toml::schema::TomlTrimPaths;
+use crate::util::toml::schema::TomlTrimPathsValue;
+use crate::util::toml::schema::{
     ProfilePackageSpec, StringOrBool, TomlDebugInfo, TomlProfile, TomlProfiles,
 };
 use crate::util::{closest_msg, config, CargoResult, Config};

src/cargo/core/workspace.rs

@@ -22,7 +22,9 @@ use crate::sources::{PathSource, CRATES_IO_INDEX, CRATES_IO_REGISTRY};
 use crate::util::edit_distance;
 use crate::util::errors::{CargoResult, ManifestError};
 use crate::util::interning::InternedString;
-use crate::util::toml::{read_manifest, InheritableFields, TomlDependency, TomlProfiles};
+use crate::util::toml::{
+    read_manifest, schema::InheritableFields, schema::TomlDependency, schema::TomlProfiles,
+};
 use crate::util::RustVersion;
 use crate::util::{config::ConfigRelativePath, Config, Filesystem, IntoUrl};
 use cargo_util::paths;

src/cargo/lib.rs

@@ -93,7 +93,7 @@
 //! Files that interact with cargo include
 //!
 //! - Package
-//!   - `Cargo.toml`: User-written project manifest, loaded with [`util::toml::TomlManifest`] and then
+//!   - `Cargo.toml`: User-written project manifest, loaded with [`util::toml::schema::TomlManifest`] and then
 //!     translated to [`core::manifest::Manifest`] which maybe stored in a [`core::Package`].
 //!     - This is editable with [`util::toml_mut::manifest::LocalManifest`]
 //!   - `Cargo.lock`: Generally loaded with [`ops::resolve_ws`] or a variant of it into a [`core::resolver::Resolve`]

src/cargo/ops/cargo_package.rs

@@ -16,7 +16,7 @@ use crate::sources::PathSource;
 use crate::util::cache_lock::CacheLockMode;
 use crate::util::config::JobsConfig;
 use crate::util::errors::CargoResult;
-use crate::util::toml::TomlManifest;
+use crate::util::toml::schema::TomlManifest;
 use crate::util::{self, human_readable_bytes, restricted_names, Config, FileLock};
 use crate::{drop_println, ops};
 use anyhow::Context as _;

src/cargo/util/command_prelude.rs

@@ -7,7 +7,7 @@ use crate::util::important_paths::find_root_manifest_for_wd;
 use crate::util::interning::InternedString;
 use crate::util::is_rustup;
 use crate::util::restricted_names::is_glob_pattern;
-use crate::util::toml::{StringOrVec, TomlProfile};
+use crate::util::toml::schema::{StringOrVec, TomlProfile};
 use crate::util::validate_package_name;
 use crate::util::{
     print_available_benches, print_available_binaries, print_available_examples,