Auto merge of #107549 - Zoxc:rustc-shared, r=jyn514

Move code in `rustc_driver` out to a new `rustc_driver_impl` crate to allow pipelining

That adds a `rustc_shared` library which contains all the rustc library crates in a single dylib. It takes over this role from `rustc_driver`. This is done so that `rustc_driver` can be compiled in parallel with other crates. `rustc_shared` is intentionally left empty so it only does linking.

An alternative could be to move the code currently in `rustc_driver` into a new crate to avoid changing the name of the distributed library.

Cargo.lock

@@ -3567,6 +3567,7 @@ dependencies = [
  "jemalloc-sys",
  "rustc_codegen_ssa",
  "rustc_driver",
+ "rustc_driver_impl",
  "rustc_smir",
 ]
 
@@ -3946,6 +3947,13 @@ dependencies = [
 [[package]]
 name = "rustc_driver"
 version = "0.0.0"
+dependencies = [
+ "rustc_driver_impl",
+]
+
+[[package]]
+name = "rustc_driver_impl"
+version = "0.0.0"
 dependencies = [
  "libc",
  "rustc_ast",

compiler/rustc/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [dependencies]
 rustc_driver = { path = "../rustc_driver" }
+rustc_driver_impl = { path = "../rustc_driver_impl" }
 
 # Make sure rustc_codegen_ssa ends up in the sysroot, because this
 # crate is intended to be used by codegen backends, which may not be in-tree.
@@ -20,6 +21,6 @@ features = ['unprefixed_malloc_on_supported_platforms']
 
 [features]
 jemalloc = ['jemalloc-sys']
-llvm = ['rustc_driver/llvm']
-max_level_info = ['rustc_driver/max_level_info']
-rustc_use_parallel_compiler = ['rustc_driver/rustc_use_parallel_compiler']
+llvm = ['rustc_driver_impl/llvm']
+max_level_info = ['rustc_driver_impl/max_level_info']
+rustc_use_parallel_compiler = ['rustc_driver_impl/rustc_use_parallel_compiler']

compiler/rustc_driver/Cargo.toml

@@ -7,39 +7,4 @@ edition = "2021"
 crate-type = ["dylib"]
 
 [dependencies]
-tracing = { version = "0.1.35" }
-serde_json = "1.0.59"
-rustc_log = { path = "../rustc_log" }
-rustc_middle = { path = "../rustc_middle" }
-rustc_ast_pretty = { path = "../rustc_ast_pretty" }
-rustc_target = { path = "../rustc_target" }
-rustc_lint = { path = "../rustc_lint" }
-rustc_data_structures = { path = "../rustc_data_structures" }
-rustc_errors = { path = "../rustc_errors" }
-rustc_feature = { path = "../rustc_feature" }
-rustc_hir = { path = "../rustc_hir" }
-rustc_hir_pretty = { path = "../rustc_hir_pretty" }
-rustc_macros = { path = "../rustc_macros" }
-rustc_metadata = { path = "../rustc_metadata" }
-rustc_parse = { path = "../rustc_parse" }
-rustc_plugin_impl = { path = "../rustc_plugin_impl" }
-rustc_save_analysis = { path = "../rustc_save_analysis" }
-rustc_codegen_ssa = { path = "../rustc_codegen_ssa" }
-rustc_session = { path = "../rustc_session" }
-rustc_error_codes = { path = "../rustc_error_codes" }
-rustc_interface = { path = "../rustc_interface" }
-rustc_ast = { path = "../rustc_ast" }
-rustc_span = { path = "../rustc_span" }
-rustc_hir_analysis = { path = "../rustc_hir_analysis" }
-
-[target.'cfg(unix)'.dependencies]
-libc = "0.2"
-
-[target.'cfg(windows)'.dependencies]
-winapi = { version = "0.3", features = ["consoleapi", "debugapi", "processenv"] }
-
-[features]
-llvm = ['rustc_interface/llvm']
-max_level_info = ['rustc_log/max_level_info']
-rustc_use_parallel_compiler = ['rustc_data_structures/rustc_use_parallel_compiler', 'rustc_interface/rustc_use_parallel_compiler',
-    'rustc_middle/rustc_use_parallel_compiler']
+rustc_driver_impl = { path = "../rustc_driver_impl" }