Auto merge of #64316 - alexcrichton:cleanup-shim, r=Mark-Simulacrum

Delete most of `src/bootstrap/bin/rustc.rs`

This commit is an attempt at deleting as much of the `rustc.rs` shim that we have in rustbuild as possible.  This shim predates `RUSTFLAGS` and is as old as rustbuild itself. While useful for quick hacks, it subverts Cargo's knowledge of `rustc`, makes it more difficult to build crates out of rustbuild, and is generally a hazard/code smell due to its architecture.

Additionally since the inception of this script we've added a number of features to Cargo such as profile overrides and `RUSTFLAGS`. This commit attempts to use these features of Cargo as much as possible to delete almost all of `src/bootstrap/bin/rustc.rs`. It's hoped that all new configuration for the Rust compiler can be codified in rustbuild rather than in this shim, allowing Cargo to have more knowledge about what's going on and making it a bit easier to reproduce builds outside of Cargo itself.

This was primarily motivated by some recent work on std-aware Cargo, and is also generally a cleanup of the script itself. This internally resulted in a number of refactorings of rustbuild itself, and the commits should be readable one-at-a-time instead of having to digest them all at once.

1 files changed, 6 insertions, 10 deletions

diff --git a/src/bootstrap/tool.rs b/src/bootstrap/tool.rs
index 54fe26f18e7..f1baeafe26a 100644
--- a/src/bootstrap/tool.rs
+++ b/src/bootstrap/tool.rs
@@ -8,7 +8,7 @@ use build_helper::t;
 
 use crate::Mode;
 use crate::Compiler;
-use crate::builder::{Step, RunConfig, ShouldRun, Builder};
+use crate::builder::{Step, RunConfig, ShouldRun, Builder, Cargo as CargoCommand};
 use crate::util::{exe, add_lib_path, CiEnv};
 use crate::compile;
 use crate::channel::GitInfo;
@@ -63,7 +63,7 @@ impl Step for ToolBuild {
             _ => panic!("unexpected Mode for tool build")
         }
 
-        let mut cargo = prepare_tool_cargo(
+        let cargo = prepare_tool_cargo(
             builder,
             compiler,
             self.mode,
@@ -76,7 +76,7 @@ impl Step for ToolBuild {
 
         builder.info(&format!("Building stage{} tool {} ({})", compiler.stage, tool, target));
         let mut duplicates = Vec::new();
-        let is_expected = compile::stream_cargo(builder, &mut cargo, vec![], &mut |msg| {
+        let is_expected = compile::stream_cargo(builder, cargo, vec![], &mut |msg| {
             // Only care about big things like the RLS/Cargo for now
             match tool {
                 | "rls"
@@ -229,15 +229,11 @@ pub fn prepare_tool_cargo(
     path: &'static str,
     source_type: SourceType,
     extra_features: &[String],
-) -> Command {
+) -> CargoCommand {
     let mut cargo = builder.cargo(compiler, mode, target, command);
     let dir = builder.src.join(path);
     cargo.arg("--manifest-path").arg(dir.join("Cargo.toml"));
 
-    // We don't want to build tools dynamically as they'll be running across
-    // stages and such and it's just easier if they're not dynamically linked.
-    cargo.env("RUSTC_NO_PREFER_DYNAMIC", "1");
-
     if source_type == SourceType::Submodule {
         cargo.env("RUSTC_EXTERNAL_TOOL", "1");
     }
@@ -517,7 +513,7 @@ impl Step for Rustdoc {
         // libraries here. The intuition here is that If we've built a compiler, we should be able
         // to build rustdoc.
 
-        let mut cargo = prepare_tool_cargo(
+        let cargo = prepare_tool_cargo(
             builder,
             build_compiler,
             Mode::ToolRustc,
@@ -530,7 +526,7 @@ impl Step for Rustdoc {
 
         builder.info(&format!("Building rustdoc for stage{} ({})",
             target_compiler.stage, target_compiler.host));
-        builder.run(&mut cargo);
+        builder.run(&mut cargo.into());
 
         // Cargo adds a number of paths to the dylib search path on windows, which results in
         // the wrong rustdoc being executed. To avoid the conflicting rustdocs, we name the "tool"