Port some bash scripts to pure shell (#3888)

Update some bash scripts to pure shell to ensure more consistent
behavior on Posix systems.

Author: UebelAndre

crate_universe/src/metadata/cargo_tree_resolver.rs

@@ -1119,8 +1119,8 @@ mod test {
         } else {
             dedent(
                 r#"
-                #!/usr/bin/env bash
-                set -euo pipefail
+                #!/bin/sh
+                set -eu
                 cat << EOF
                 "#,
             ) + &text
@@ -1166,8 +1166,8 @@ mod test {
         } else {
             dedent(
                 r#"
-                #!/usr/bin/env bash
-                set -euo pipefail
+                #!/bin/sh
+                set -eu
                 echo "$@"
                 "#,
             )
@@ -1216,8 +1216,8 @@ mod test {
         } else {
             dedent(
                 r#"
-                #!/usr/bin/env bash
-                set -euo pipefail
+                #!/bin/sh
+                set -eu
                 echo "$@"
                 "#,
             )

crate_universe/src/metadata/cargo_tree_rustc_wrapper.sh

@@ -1,37 +1,50 @@
-#!/usr/bin/env bash
+#!/bin/sh
 #
 # For details, see:
 # `@rules_rust//crate_universe/src/metadata/cargo_tree_resolver.rs - TreeResolver::create_rustc_wrapper`
 
-set -euo pipefail
+set -eu
 
 # When cargo is detecting the host configuration, the host target needs to be
 # injected into the command.
-if [[ "$@" == *"rustc - --crate-name ___ "* && "$@" != *" --target "* ]]; then
-    exec "$@" --target "${HOST_TRIPLE}"
-fi
+case "$*" in
+    *"rustc - --crate-name ___ "*)
+        case "$*" in
+            *" --target "*) ;;
+            *)
+                exec "$@" --target "${HOST_TRIPLE}"
+                ;;
+        esac
+        ;;
+esac
 
 # When querying info about the compiler, ensure the triple is mocked out to be
 # the desired target triple for the host.
-if [[ "$@" == *"rustc -Vv" || "$@" == *"rustc -vV" ]]; then
-    set +e
-    _RUSTC_OUTPUT="$($@)"
-    _EXIT_CODE=$?
-    set -e
+case "$*" in
+    *"rustc -Vv"*|*"rustc -vV"*)
+        set +e
+        _RUSTC_OUTPUT="$("$@")"
+        _EXIT_CODE=$?
+        set -e
 
-    # Loop through each line of the output
-    while IFS= read -r line; do
-        # If the line starts with "host:", replace it with the new host value
-        if [[ "${line}" == host:* ]]; then
-            echo "host: ${HOST_TRIPLE}"
-        else
-            # Print the other lines unchanged
-            echo "${line}"
-        fi
-    done <<<"${_RUSTC_OUTPUT}"
+        # Loop through each line of the output
+        while IFS= read -r line; do
+            # If the line starts with "host:", replace it with the new host value
+            case "${line}" in
+                host:*)
+                    echo "host: ${HOST_TRIPLE}"
+                    ;;
+                *)
+                    echo "${line}"
+                    ;;
+            esac
+        done <<EOF
+${_RUSTC_OUTPUT}
+EOF
 
-    exit ${_EXIT_CODE}
-fi
+        exit ${_EXIT_CODE}
+        ;;
+esac
 
 # If there is nothing special to do then simply forward the call
 exec "$@"

test/process_wrapper_bootstrap/bootstrap_process_wrapper_test.rs

@@ -18,7 +18,7 @@ fn test_shebang() {
 
     let content = read_to_string(script).unwrap();
     assert!(
-        content.starts_with("#!/usr/bin/env bash"),
+        content.starts_with("#!/bin/sh"),
         "The shell script does not start with the expected shebang."
     )
 }

util/process_wrapper/private/bootstrap_process_wrapper.bzl

@@ -15,7 +15,7 @@ def _bootstrap_process_wrapper_impl_unix(ctx):
             substitutions = {
                 # Replace the shebang with one constructed from the configured
                 # shell toolchain.
-                "#!/usr/bin/env bash": shebang,
+                "#!/bin/sh": shebang,
             },
         )
     else:

util/process_wrapper/private/process_wrapper.sh

@@ -1,18 +1,21 @@
-#!/usr/bin/env bash
+#!/bin/sh
 
-set -euo pipefail
+set -eu
 
 # Skip the first argument which is expected to be `--`
 shift
 
-args=()
-
 for arg in "$@"; do
-    # Check if the argument contains "${PWD}" and replace it with the actual value of PWD
-    if [[ "${arg}" == *'${pwd}'* ]]; then
-        arg="${arg//\$\{pwd\}/$PWD}"
-    fi
-    args+=("${arg}")
+    case "$arg" in
+        *'${pwd}'*)
+            # Split on '${pwd}' and rejoin with the actual PWD value
+            prefix="${arg%%\$\{pwd\}*}"
+            suffix="${arg#*\$\{pwd\}}"
+            arg="${prefix}${PWD}${suffix}"
+            ;;
+    esac
+    set -- "$@" "$arg"
+    shift
 done
 
-exec "${args[@]}"
+exec "$@"