Rollup merge of rust-lang#98994 - kons-9:dont_use_process_exit, r=jyn514

replace process exit with more detailed exit in src/bootstrap/*.rs

Fixes [rust-lang#98830](rust-lang#98830)

I implemeted "detail_exit.rs" in lib.rs, and replace all of std::process::exit.
So, error code should panic in test code.
```
// lib.rs
pub fn detail_exit(code: i32) -> ! {
    // Successful exit
    if code == 0 {
        std::process::exit(0);
    }
    if cfg!(test) {
        panic!("status code: {}", code);
    } else {
        std::panic::resume_unwind(Box::new(code));
    }
}
```

<details>
<summary>% rg "exit\(" src/bootstrap/*.rs</summary>

```
builder.rs
351:            crate::detail_exit(1);
1000:            crate::detail_exit(1);
1429:                    crate::detail_exit(1);

compile.rs
1331:        crate::detail_exit(1);

config.rs
818:                    crate::detail_exit(2);
1488:        crate::detail_exit(1);

flags.rs
263:                crate::detail_exit(exit_code);
349:            crate::detail_exit(exit_code);
381:            crate::detail_exit(1);
602:                        crate::detail_exit(1);
616:                crate::detail_exit(1);
807:            crate::detail_exit(1);

format.rs
35:            crate::detail_exit(1);
117:        crate::detail_exit(1);

lib.rs
714:            detail_exit(1);
1620:                detail_exit(1);
1651:pub fn detail_exit(code: i32) -> ! {
1654:        std::process::exit(0);

sanity.rs
107:            crate::detail_exit(1);

setup.rs
97:        crate::detail_exit(1);
290:            crate::detail_exit(1);

test.rs
676:            crate::detail_exit(1);
1024:                crate::detail_exit(1);
1254:            crate::detail_exit(1);

tool.rs
207:                crate::detail_exit(1);

toolstate.rs
96:    crate::detail_exit(3);
111:            crate::detail_exit(1);
182:            crate::detail_exit(1);
228:            crate::detail_exit(1);

util.rs
339:        crate::detail_exit(1);
378:        crate::detail_exit(1);
468:    crate::detail_exit(1);
```
</details>

Author: matthiaskrgr

src/bootstrap/builder.rs

@@ -346,11 +346,7 @@ impl StepDescription {
             eprintln!(
                 "note: if you are adding a new Step to bootstrap itself, make sure you register it with `describe!`"
             );
-            #[cfg(not(test))]
-            std::process::exit(1);
-            #[cfg(test)]
-            // so we can use #[should_panic]
-            panic!()
+            crate::detail_exit(1);
         }
     }
 }
@@ -1008,7 +1004,7 @@ impl<'a> Builder<'a> {
             if !help_on_error.is_empty() {
                 eprintln!("{}", help_on_error);
             }
-            std::process::exit(1);
+            crate::detail_exit(1);
         }
     }
 
@@ -1437,7 +1433,7 @@ impl<'a> Builder<'a> {
                         "error: `x.py clippy` requires a host `rustc` toolchain with the `clippy` component"
                     );
                     eprintln!("help: try `rustup component add clippy`");
-                    std::process::exit(1);
+                    crate::detail_exit(1);
                 });
                 if !t!(std::str::from_utf8(&output.stdout)).contains("nightly") {
                     rustflags.arg("--cfg=bootstrap");

src/bootstrap/compile.rs

@@ -13,7 +13,7 @@ use std::fs;
 use std::io::prelude::*;
 use std::io::BufReader;
 use std::path::{Path, PathBuf};
-use std::process::{exit, Command, Stdio};
+use std::process::{Command, Stdio};
 use std::str;
 
 use serde::Deserialize;
@@ -1377,7 +1377,7 @@ pub fn run_cargo(
     });
 
     if !ok {
-        exit(1);
+        crate::detail_exit(1);
     }
 
     // Ok now we need to actually find all the files listed in `toplevel`. We've

src/bootstrap/config.rs

@@ -11,7 +11,7 @@ use std::ffi::OsStr;
 use std::fmt;
 use std::fs;
 use std::path::{Path, PathBuf};
-use std::process::{exit, Command};
+use std::process::Command;
 use std::str::FromStr;
 
 use crate::builder::{Builder, TaskPath};
@@ -805,8 +805,6 @@ impl Config {
         let get_toml = |_| TomlConfig::default();
         #[cfg(not(test))]
         let get_toml = |file: &Path| {
-            use std::process;
-
             let contents =
                 t!(fs::read_to_string(file), format!("config file {} not found", file.display()));
             // Deserialize to Value and then TomlConfig to prevent the Deserialize impl of
@@ -817,7 +815,7 @@ impl Config {
                 Ok(table) => table,
                 Err(err) => {
                     eprintln!("failed to parse TOML configuration '{}': {}", file.display(), err);
-                    process::exit(2);
+                    crate::detail_exit(2);
                 }
             }
         };
@@ -1487,7 +1485,7 @@ fn download_ci_rustc_commit(
         println!("help: maybe your repository history is too shallow?");
         println!("help: consider disabling `download-rustc`");
         println!("help: or fetch enough history to include one upstream commit");
-        exit(1);
+        crate::detail_exit(1);
     }
 
     // Warn if there were changes to the compiler or standard library since the ancestor commit.

src/bootstrap/flags.rs

@@ -4,7 +4,6 @@
 //! has various flags to configure how it's run.
 
 use std::path::PathBuf;
-use std::process;
 
 use getopts::Options;
 
@@ -261,7 +260,7 @@ To learn more about a subcommand, run `./x.py <subcommand> -h`",
                 // subcommand.
                 println!("{}\n", subcommand_help);
                 let exit_code = if args.is_empty() { 0 } else { 1 };
-                process::exit(exit_code);
+                crate::detail_exit(exit_code);
             }
         };
 
@@ -347,7 +346,7 @@ To learn more about a subcommand, run `./x.py <subcommand> -h`",
             } else if verbose {
                 panic!("No paths available for subcommand `{}`", subcommand.as_str());
             }
-            process::exit(exit_code);
+            crate::detail_exit(exit_code);
         };
 
         // Done specifying what options are possible, so do the getopts parsing
@@ -379,7 +378,7 @@ To learn more about a subcommand, run `./x.py <subcommand> -h`",
                 "Sorry, I couldn't figure out which subcommand you were trying to specify.\n\
                  You may need to move some options to after the subcommand.\n"
             );
-            process::exit(1);
+            crate::detail_exit(1);
         }
         // Extra help text for some commands
         match subcommand {
@@ -600,7 +599,7 @@ Arguments:
                         eprintln!("error: {}", err);
                         eprintln!("help: the available profiles are:");
                         eprint!("{}", Profile::all_for_help("- "));
-                        std::process::exit(1);
+                        crate::detail_exit(1);
                     })
                 } else {
                     t!(crate::setup::interactive_path())
@@ -614,7 +613,7 @@ Arguments:
                 || matches.opt_str("keep-stage-std").is_some()
             {
                 eprintln!("--keep-stage not yet supported for x.py check");
-                process::exit(1);
+                crate::detail_exit(1);
             }
         }
 
@@ -805,7 +804,7 @@ fn parse_deny_warnings(matches: &getopts::Matches) -> Option<bool> {
         Some("warn") => Some(false),
         Some(value) => {
             eprintln!(r#"invalid value for --warnings: {:?}, expected "warn" or "deny""#, value,);
-            process::exit(1);
+            crate::detail_exit(1);
         }
         None => None,
     }

src/bootstrap/format.rs

@@ -32,7 +32,7 @@ fn rustfmt(src: &Path, rustfmt: &Path, paths: &[PathBuf], check: bool) -> impl F
                         code, run `./x.py fmt` instead.",
                 cmd_debug,
             );
-            std::process::exit(1);
+            crate::detail_exit(1);
         }
     }
 }
@@ -114,7 +114,7 @@ pub fn format(build: &Builder<'_>, check: bool, paths: &[PathBuf]) {
 
     let rustfmt_path = build.initial_rustfmt().unwrap_or_else(|| {
         eprintln!("./x.py fmt is not supported on this channel");
-        std::process::exit(1);
+        crate::detail_exit(1);
     });
     assert!(rustfmt_path.exists(), "{}", rustfmt_path.display());
     let src = build.src.clone();

src/bootstrap/lib.rs

@@ -109,7 +109,7 @@ use std::env;
 use std::fs::{self, File};
 use std::io;
 use std::path::{Path, PathBuf};
-use std::process::{self, Command};
+use std::process::Command;
 use std::str;
 
 use filetime::FileTime;
@@ -711,7 +711,7 @@ impl Build {
             for failure in failures.iter() {
                 eprintln!("  - {}\n", failure);
             }
-            process::exit(1);
+            detail_exit(1);
         }
 
         #[cfg(feature = "build-metrics")]
@@ -1617,7 +1617,7 @@ Alternatively, set `download-ci-llvm = true` in that `[llvm]` section
 to download LLVM rather than building it.
 "
                 );
-                std::process::exit(1);
+                detail_exit(1);
             }
         }
 
@@ -1646,6 +1646,20 @@ fn chmod(path: &Path, perms: u32) {
 #[cfg(windows)]
 fn chmod(_path: &Path, _perms: u32) {}
 
+/// If code is not 0 (successful exit status), exit status is 101 (rust's default error code.)
+/// If the test is running and code is an error code, it will cause a panic.
+fn detail_exit(code: i32) -> ! {
+    // Successful exit
+    if code == 0 {
+        std::process::exit(0);
+    }
+    if cfg!(test) {
+        panic!("status code: {}", code);
+    } else {
+        std::panic::resume_unwind(Box::new(code));
+    }
+}
+
 impl Compiler {
     pub fn with_stage(mut self, stage: u32) -> Compiler {
         self.stage = stage;

src/bootstrap/sanity.rs

@@ -104,7 +104,7 @@ You should install cmake, or set `download-ci-llvm = true` in the
 than building it.
 "
             );
-            std::process::exit(1);
+            crate::detail_exit(1);
         }
     }
 

src/bootstrap/setup.rs

@@ -94,7 +94,7 @@ pub fn setup(config: &Config, profile: Profile) {
             "note: this will use the configuration in {}",
             profile.include_path(&config.src).display()
         );
-        std::process::exit(1);
+        crate::detail_exit(1);
     }
 
     let settings = format!(
@@ -287,7 +287,7 @@ pub fn interactive_path() -> io::Result<Profile> {
         io::stdin().read_line(&mut input)?;
         if input.is_empty() {
             eprintln!("EOF on stdin, when expecting answer to question.  Giving up.");
-            std::process::exit(1);
+            crate::detail_exit(1);
         }
         break match parse_with_abbrev(&input) {
             Ok(profile) => profile,

src/bootstrap/test.rs

@@ -673,7 +673,7 @@ impl Step for Clippy {
         }
 
         if !builder.config.cmd.bless() {
-            std::process::exit(1);
+            crate::detail_exit(1);
         }
 
         let mut cargo = builder.cargo(compiler, Mode::ToolRustc, SourceType::InTree, host, "run");
@@ -1021,7 +1021,7 @@ help: to skip test's attempt to check tidiness, pass `--exclude src/tools/tidy`
                     PATH = inferred_rustfmt_dir.display(),
                     CHAN = builder.config.channel,
                 );
-                std::process::exit(1);
+                crate::detail_exit(1);
             }
             crate::format::format(&builder, !builder.config.cmd.bless(), &[]);
         }
@@ -1251,7 +1251,7 @@ help: to test the compiler, use `--stage 1` instead
 help: to test the standard library, use `--stage 0 library/std` instead
 note: if you're sure you want to do this, please open an issue as to why. In the meantime, you can override this with `COMPILETEST_FORCE_STAGE0=1`."
             );
-            std::process::exit(1);
+            crate::detail_exit(1);
         }
 
         let compiler = self.compiler;

src/bootstrap/tool.rs

@@ -2,7 +2,7 @@ use std::collections::HashSet;
 use std::env;
 use std::fs;
 use std::path::{Path, PathBuf};
-use std::process::{exit, Command};
+use std::process::Command;
 
 use crate::builder::{Builder, Cargo as CargoCommand, RunConfig, ShouldRun, Step};
 use crate::channel::GitInfo;
@@ -204,7 +204,7 @@ impl Step for ToolBuild {
 
         if !is_expected {
             if !is_optional_tool {
-                exit(1);
+                crate::detail_exit(1);
             } else {
                 None
             }