Auto merge of #13479 - epage:cfg, r=weihanglo

fix(cli): Respect CARGO_TERM_COLOR in '--list' and '-Zhelp'

### What does this PR try to resolve?

Similar to #9012, we aren't respecting `CARGO_TERM_COLOR` for `-Zhelp` and other places.  This corrects that.

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

#9012 was about initialization order to get the value.  Here, the problem is that we don't update `Shell` with `CARGO_TERM_COLOR`.

In doing this, I was concerned about keeping track of where it is safe to call `config_configure` without running it twice.  To this end, I refactored `main` to make it clear that each call to `config_configure` is in a mutually exclusive path that exists immediately.

### Additional information

Found this with the test for `-Zhelp` in #13461.

src/bin/cargo/cli.rs

@@ -48,11 +48,55 @@ pub fn main(gctx: &mut GlobalContext) -> CliResult {
 
     let (expanded_args, global_args) = expand_aliases(gctx, args, vec![])?;
 
+    let is_verbose = expanded_args.verbose() > 0;
+
     if expanded_args
         .get_one::<String>("unstable-features")
         .map(String::as_str)
         == Some("help")
     {
+        // Don't let config errors get in the way of parsing arguments
+        let _ = config_configure(gctx, &expanded_args, None, global_args, None);
+        print_zhelp(gctx);
+    } else if expanded_args.flag("version") {
+        // Don't let config errors get in the way of parsing arguments
+        let _ = config_configure(gctx, &expanded_args, None, global_args, None);
+        let version = get_version_string(is_verbose);
+        drop_print!(gctx, "{}", version);
+    } else if let Some(code) = expanded_args.get_one::<String>("explain") {
+        // Don't let config errors get in the way of parsing arguments
+        let _ = config_configure(gctx, &expanded_args, None, global_args, None);
+        let mut procss = gctx.load_global_rustc(None)?.process();
+        procss.arg("--explain").arg(code).exec()?;
+    } else if expanded_args.flag("list") {
+        // Don't let config errors get in the way of parsing arguments
+        let _ = config_configure(gctx, &expanded_args, None, global_args, None);
+        print_list(gctx, is_verbose);
+    } else {
+        let (cmd, subcommand_args) = match expanded_args.subcommand() {
+            Some((cmd, args)) => (cmd, args),
+            _ => {
+                // No subcommand provided.
+                cli(gctx).print_help()?;
+                return Ok(());
+            }
+        };
+        let exec = Exec::infer(cmd)?;
+        config_configure(
+            gctx,
+            &expanded_args,
+            Some(subcommand_args),
+            global_args,
+            Some(&exec),
+        )?;
+        super::init_git(gctx);
+
+        exec.exec(gctx, subcommand_args)?;
+    }
+    Ok(())
+}
+
+fn print_zhelp(gctx: &GlobalContext) {
     let header = style::HEADER;
     let literal = style::LITERAL;
     let placeholder = style::PLACEHOLDER;
@@ -97,23 +141,9 @@ Run with `{literal}cargo -Z{literal:#} {placeholder}[FLAG] [COMMAND]{placeholder
         "\nSee https://doc.rust-lang.org/nightly/cargo/reference/unstable.html \
              for more information about these flags."
     );
-        return Ok(());
 }
 
-    let is_verbose = expanded_args.verbose() > 0;
+fn print_list(gctx: &GlobalContext, is_verbose: bool) {
-    if expanded_args.flag("version") {
-        let version = get_version_string(is_verbose);
-        drop_print!(gctx, "{}", version);
-        return Ok(());
-    }
-
-    if let Some(code) = expanded_args.get_one::<String>("explain") {
-        let mut procss = gctx.load_global_rustc(None)?.process();
-        procss.arg("--explain").arg(code).exec()?;
-        return Ok(());
-    }
-
-    if expanded_args.flag("list") {
     // Maps from commonly known external commands (not builtin to cargo)
     // to their description, for the help page. Reserved for external
     // subcommands that are core within the rust ecosystem (esp ones that
@@ -167,22 +197,6 @@ Run with `{literal}cargo -Z{literal:#} {placeholder}[FLAG] [COMMAND]{placeholder
             }
         }
     }
-        return Ok(());
-    }
-
-    let (cmd, subcommand_args) = match expanded_args.subcommand() {
-        Some((cmd, args)) => (cmd, args),
-        _ => {
-            // No subcommand provided.
-            cli(gctx).print_help()?;
-            return Ok(());
-        }
-    };
-    let exec = Exec::infer(cmd)?;
-    config_configure(gctx, &expanded_args, subcommand_args, global_args, &exec)?;
-    super::init_git(gctx);
-
-    exec.exec(gctx, subcommand_args)
 }
 
 pub fn get_version_string(is_verbose: bool) -> String {
@@ -365,16 +379,18 @@ For more information, see issue #12207 <https://github.com/rust-lang/cargo/issue
 fn config_configure(
     gctx: &mut GlobalContext,
     args: &ArgMatches,
-    subcommand_args: &ArgMatches,
+    subcommand_args: Option<&ArgMatches>,
     global_args: GlobalArgs,
-    exec: &Exec,
+    exec: Option<&Exec>,
 ) -> CliResult {
-    let arg_target_dir = &subcommand_args.value_of_path("target-dir", gctx);
+    let arg_target_dir = &subcommand_args.and_then(|a| a.value_of_path("target-dir", gctx));
     let mut verbose = global_args.verbose + args.verbose();
     // quiet is unusual because it is redefined in some subcommands in order
     // to provide custom help text.
-    let mut quiet = args.flag("quiet") || subcommand_args.flag("quiet") || global_args.quiet;
+    let mut quiet = args.flag("quiet")
-    if matches!(exec, Exec::Manifest(_)) && !quiet {
+        || subcommand_args.map(|a| a.flag("quiet")).unwrap_or_default()
+        || global_args.quiet;
+    if matches!(exec, Some(Exec::Manifest(_))) && !quiet {
         // Verbosity is shifted quieter for `Exec::Manifest` as it is can be used as if you ran
         // `cargo install` and we especially shouldn't pollute programmatic output.
         //

src/cargo/util/config/mod.rs

@@ -1018,6 +1018,49 @@ impl GlobalContext {
         unstable_flags: &[String],
         cli_config: &[String],
     ) -> CargoResult<()> {
+        // Ignore errors in the configuration files. We don't want basic
+        // commands like `cargo version` to error out due to config file
+        // problems.
+        let term = self.get::<TermConfig>("term").unwrap_or_default();
+
+        // The command line takes precedence over configuration.
+        let extra_verbose = verbose >= 2;
+        let verbose = verbose != 0;
+        let verbosity = match (verbose, quiet) {
+            (true, true) => bail!("cannot set both --verbose and --quiet"),
+            (true, false) => Verbosity::Verbose,
+            (false, true) => Verbosity::Quiet,
+            (false, false) => match (term.verbose, term.quiet) {
+                (Some(true), Some(true)) => {
+                    bail!("cannot set both `term.verbose` and `term.quiet`")
+                }
+                (Some(true), _) => Verbosity::Verbose,
+                (_, Some(true)) => Verbosity::Quiet,
+                _ => Verbosity::Normal,
+            },
+        };
+        self.shell().set_verbosity(verbosity);
+        self.extra_verbose = extra_verbose;
+
+        let color = color.or_else(|| term.color.as_deref());
+        self.shell().set_color_choice(color)?;
+        if let Some(hyperlinks) = term.hyperlinks {
+            self.shell().set_hyperlinks(hyperlinks)?;
+        }
+
+        self.progress_config = term.progress.unwrap_or_default();
+
+        self.frozen = frozen;
+        self.locked = locked;
+        self.offline = offline
+            || self
+                .net_config()
+                .ok()
+                .and_then(|n| n.offline)
+                .unwrap_or(false);
+        let cli_target_dir = target_dir.as_ref().map(|dir| Filesystem::new(dir.clone()));
+        self.target_dir = cli_target_dir;
+
         for warning in self
             .unstable_flags
             .parse(unstable_flags, self.nightly_features_allowed)?
@@ -1042,49 +1085,6 @@ impl GlobalContext {
             // before configure). This can be removed when stabilized.
             self.reload_rooted_at(self.cwd.clone())?;
         }
-        let extra_verbose = verbose >= 2;
-        let verbose = verbose != 0;
-
-        // Ignore errors in the configuration files. We don't want basic
-        // commands like `cargo version` to error out due to config file
-        // problems.
-        let term = self.get::<TermConfig>("term").unwrap_or_default();
-
-        let color = color.or_else(|| term.color.as_deref());
-
-        // The command line takes precedence over configuration.
-        let verbosity = match (verbose, quiet) {
-            (true, true) => bail!("cannot set both --verbose and --quiet"),
-            (true, false) => Verbosity::Verbose,
-            (false, true) => Verbosity::Quiet,
-            (false, false) => match (term.verbose, term.quiet) {
-                (Some(true), Some(true)) => {
-                    bail!("cannot set both `term.verbose` and `term.quiet`")
-                }
-                (Some(true), _) => Verbosity::Verbose,
-                (_, Some(true)) => Verbosity::Quiet,
-                _ => Verbosity::Normal,
-            },
-        };
-
-        let cli_target_dir = target_dir.as_ref().map(|dir| Filesystem::new(dir.clone()));
-
-        self.shell().set_verbosity(verbosity);
-        self.shell().set_color_choice(color)?;
-        if let Some(hyperlinks) = term.hyperlinks {
-            self.shell().set_hyperlinks(hyperlinks)?;
-        }
-        self.progress_config = term.progress.unwrap_or_default();
-        self.extra_verbose = extra_verbose;
-        self.frozen = frozen;
-        self.locked = locked;
-        self.offline = offline
-            || self
-                .net_config()
-                .ok()
-                .and_then(|n| n.offline)
-                .unwrap_or(false);
-        self.target_dir = cli_target_dir;
 
         self.load_unstable_flags_from_config()?;