Improve CurrentProcess

To bring in tokio runtime pervasively we need to evolve CurrentProcess
to be a bit more friendly with Send/Sync. Getting at the concrete types
is actually clearer than what we had I think, and should ease that
process.

Author: rbtcollins

Cargo.lock

@@ -55,6 +55,7 @@ derivative.workspace = true
 download = { path = "download", default-features = false }
 effective-limits = "0.5.5"
 enum-map = "2.5.0"
+enum_dispatch.workspace = true
 flate2 = "1"
 fs_at.workspace = true
 git-testament = "0.2"
@@ -174,6 +175,7 @@ members = ["download", "rustup-macros"]
 [workspace.dependencies]
 anyhow = "1.0.69"
 derivative = "2.2.0"
+enum_dispatch = "0.3.11"
 fs_at = "0.1.6"
 lazy_static = "1"
 once_cell = "1.17.1"

Cargo.toml

@@ -23,14 +23,14 @@ use rustup::cli::rustup_mode;
 #[cfg(windows)]
 use rustup::cli::self_update;
 use rustup::cli::setup_mode;
-use rustup::currentprocess::{process, with, OSProcess};
+use rustup::currentprocess::{process, varsource::VarSource, with, OSProcess};
 use rustup::env_var::RUST_RECURSION_COUNT_MAX;
 use rustup::is_proxyable_tools;
 use rustup::utils::utils;
 
 fn main() {
     let process = OSProcess::default();
-    with(Box::new(process), || match maybe_trace_rustup() {
+    with(process.into(), || match maybe_trace_rustup() {
         Err(e) => {
             common::report_error(&e);
             std::process::exit(1);

src/bin/rustup-init.rs

@@ -14,6 +14,11 @@ use term2::Terminal;
 
 use super::self_update;
 use super::term2;
+use crate::currentprocess::argsource::ArgSource;
+use crate::currentprocess::{
+    filesource::{StdinSource, StdoutSource},
+    varsource::VarSource,
+};
 use crate::utils::notifications as util_notifications;
 use crate::utils::notify::NotificationLevel;
 use crate::utils::utils;

src/cli/common.rs

@@ -3,6 +3,7 @@ use std::io::Write;
 use term2::Terminal;
 
 use super::term2;
+use crate::currentprocess::varsource::VarSource;
 use crate::process;
 
 macro_rules! warn {

src/cli/log.rs

@@ -5,6 +5,7 @@ use anyhow::Result;
 use crate::{
     cli::{common::set_globals, job, self_update},
     command::run_command_for_dir,
+    currentprocess::argsource::ArgSource,
     toolchain::names::{LocalToolchainName, ResolvableLocalToolchainName},
     utils::utils::{self, ExitCode},
     Cfg,

src/cli/proxy_mode.rs

@@ -21,6 +21,11 @@ use crate::{
         topical_doc,
     },
     command,
+    currentprocess::{
+        argsource::ArgSource,
+        filesource::{StderrSource, StdoutSource},
+        varsource::VarSource,
+    },
     dist::{
         dist::{PartialToolchainDesc, Profile, TargetTriple},
         manifest::{Component, ComponentStatus},

src/cli/rustup_mode.rs

@@ -65,6 +65,7 @@ use crate::{
         markdown::md,
         term2::{self, Terminal},
     },
+    currentprocess::{filesource::StdoutSource, varsource::VarSource},
     dist::dist::{self, PartialToolchainDesc, Profile, TargetTriple, ToolchainDesc},
     install::UpdateStatus,
     process,
@@ -1296,11 +1297,11 @@ mod tests {
         with_rustup_home(|home| {
             let mut vars = HashMap::new();
             home.apply(&mut vars);
-            let tp = Box::new(currentprocess::TestProcess {
+            let tp = currentprocess::TestProcess {
                 vars,
                 ..Default::default()
-            });
-            currentprocess::with(tp.clone(), || -> Result<()> {
+            };
+            currentprocess::with(tp.clone().into(), || -> Result<()> {
                 // TODO: we could pass in a custom cfg to get notification
                 // callbacks rather than output to the tp sink.
                 let mut cfg = common::set_globals(false, false).unwrap();
@@ -1343,11 +1344,11 @@ info: default host triple is {0}
         let cargo_home = root_dir.path().join("cargo");
         let mut vars = HashMap::new();
         vars.env("CARGO_HOME", cargo_home.to_string_lossy().to_string());
-        let tp = Box::new(currentprocess::TestProcess {
+        let tp = currentprocess::TestProcess {
             vars,
             ..Default::default()
-        });
-        currentprocess::with(tp, || -> Result<()> {
+        };
+        currentprocess::with(tp.into(), || -> Result<()> {
             super::install_bins().unwrap();
             Ok(())
         })

src/cli/self_update.rs

@@ -29,7 +29,7 @@ use std::path::PathBuf;
 use anyhow::{bail, Result};
 
 use super::utils;
-use crate::process;
+use crate::{currentprocess::varsource::VarSource, process};
 
 pub(crate) type Shell = Box<dyn UnixShell>;
 

src/cli/self_update/shell.rs

@@ -5,6 +5,7 @@ use anyhow::{bail, Context, Result};
 
 use super::install_bins;
 use super::shell;
+use crate::currentprocess::varsource::VarSource;
 use crate::process;
 use crate::utils::utils;
 use crate::utils::Notification;