Merge remote-tracking branch 'upstream/master' into subtree_push_2023_12_12

12 files changed, 184 insertions, 14 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 8fcefa97489..ee396cce26a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -343,9 +343,9 @@ dependencies = [
 
 [[package]]
 name = "itertools"
-version = "0.10.3"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a9a9d19fa1e79b6215ff29b9d6880b706147f16e9b1dbb1e4e5947b5b02bc5e3"
+checksum = "b1c173a5686ce8bfa551b3563d0c2170bf24ca44da99c7ca4bfdab5418c3fe57"
 dependencies = [
  "either",
 ]
diff --git a/ci/check_diff.sh b/ci/check_diff.sh
index 50c58b1f492..42fdcaa6424 100755
--- a/ci/check_diff.sh
+++ b/ci/check_diff.sh
@@ -2,9 +2,6 @@
 
 set -e
 
-# https://github.com/rust-lang/rustfmt/issues/5675
-export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$LD_LIBRARY_PATH
-
 function print_usage() {
     echo "usage check_diff REMOTE_REPO FEATURE_BRANCH [COMMIT_HASH] [OPTIONAL_RUSTFMT_CONFIGS]"
 }
@@ -114,15 +111,42 @@ function compile_rustfmt() {
     git remote add feature $REMOTE_REPO
     git fetch feature $FEATURE_BRANCH
 
-    cargo build --release --bin rustfmt && cp target/release/rustfmt $1/rustfmt
+    CARGO_VERSON=$(cargo --version)
+    echo -e "\ncompiling with $CARGO_VERSON\n"
+
+    # Because we're building standalone binaries we need to set `LD_LIBRARY_PATH` so each
+    # binary can find it's runtime dependencies. See https://github.com/rust-lang/rustfmt/issues/5675
+    # This will prepend the `LD_LIBRARY_PATH` for the master rustfmt binary
+    export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$LD_LIBRARY_PATH
+
+    echo "Building rustfmt from src"
+    cargo build -q --release --bin rustfmt && cp target/release/rustfmt $1/rustfmt
+
     if [ -z "$OPTIONAL_COMMIT_HASH" ] || [ "$FEATURE_BRANCH" = "$OPTIONAL_COMMIT_HASH" ]; then
         git switch $FEATURE_BRANCH
     else
         git switch $OPTIONAL_COMMIT_HASH --detach
     fi
-    cargo build --release --bin rustfmt && cp target/release/rustfmt $1/feature_rustfmt
+
+    # This will prepend the `LD_LIBRARY_PATH` for the feature branch rustfmt binary.
+    # In most cases the `LD_LIBRARY_PATH` should be the same for both rustfmt binaries that we build
+    # in `compile_rustfmt`, however, there are scenarios where each binary has different runtime
+    # dependencies. For example, during subtree syncs we bump the nightly toolchain required to build
+    # rustfmt, and therefore the feature branch relies on a newer set of runtime dependencies.
+    export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$LD_LIBRARY_PATH
+
+    echo "Building feature rustfmt from src"
+    cargo build -q --release --bin rustfmt && cp target/release/rustfmt $1/feature_rustfmt
+
+    echo -e "\nRuntime dependencies for rustfmt -- LD_LIBRARY_PATH: $LD_LIBRARY_PATH"
+
     RUSFMT_BIN=$1/rustfmt
+    RUSTFMT_VERSION=$($RUSFMT_BIN --version)
+    echo -e "\nRUSFMT_BIN $RUSTFMT_VERSION\n"
+
     FEATURE_BIN=$1/feature_rustfmt
+    FEATURE_VERSION=$($FEATURE_BIN --version)
+    echo -e "FEATURE_BIN $FEATURE_VERSION\n"
 }
 
 # Check the diff for running rustfmt and the feature branch on all the .rs files in the repo.
@@ -155,7 +179,7 @@ function check_repo() {
     STATUSES+=($?)
     set -e
 
-    echo "removing tmp_dir $tmp_dir"
+    echo -e "removing tmp_dir $tmp_dir\n\n"
     rm -rf $tmp_dir
     cd $WORKDIR
 }
diff --git a/src/config/mod.rs b/src/config/mod.rs
index 9d454137b2c..58f8a9c264a 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -26,6 +26,7 @@ pub(crate) mod file_lines;
 #[allow(unreachable_pub)]
 pub(crate) mod lists;
 pub(crate) mod macro_names;
+pub(crate) mod style_edition;
 
 // This macro defines configuration options used in rustfmt. Each option
 // is defined as follows:
diff --git a/src/config/options.rs b/src/config/options.rs
index 03fd91eb10f..e7fd2cfbd31 100644
--- a/src/config/options.rs
+++ b/src/config/options.rs
@@ -470,3 +470,27 @@ pub enum MatchArmLeadingPipe {
     /// Preserve any existing leading pipes
     Preserve,
 }
+
+/// Defines the default values for each config according to [the style guide].
+/// rustfmt output may differ between style editions.
+///
+/// [the style guide]: https://doc.rust-lang.org/nightly/style-guide/
+#[config_type]
+pub enum StyleEdition {
+    #[value = "2015"]
+    #[doc_hint = "2015"]
+    /// [Edition 2015]()
+    Edition2015,
+    #[value = "2018"]
+    #[doc_hint = "2018"]
+    /// [Edition 2018]()
+    Edition2018,
+    #[value = "2021"]
+    #[doc_hint = "2021"]
+    /// [Edition 2021]()
+    Edition2021,
+    #[value = "2024"]
+    #[doc_hint = "2024"]
+    /// [Edition 2024]().
+    Edition2024,
+}
diff --git a/src/config/style_edition.rs b/src/config/style_edition.rs
new file mode 100644
index 00000000000..4dd5f0164fa
--- /dev/null
+++ b/src/config/style_edition.rs
@@ -0,0 +1,69 @@
+use crate::config::StyleEdition;
+
+/// Defines the default value for the given style edition
+pub(crate) trait StyleEditionDefault {
+    type ConfigType;
+    fn style_edition_default(style_edition: StyleEdition) -> Self::ConfigType;
+}
+
+/// macro to help implement `StyleEditionDefault` for config options
+#[macro_export]
+macro_rules! style_edition_default {
+    ($ty:ident, $config_ty:ty, _ => $default:expr) => {
+        impl $crate::config::style_edition::StyleEditionDefault for $ty {
+            type ConfigType = $config_ty;
+
+            fn style_edition_default(_: $crate::config::StyleEdition) -> Self::ConfigType {
+                $default
+            }
+        }
+    };
+    ($ty:ident, $config_ty:ty, Edition2024 => $default_2024:expr, _ => $default_2015:expr) => {
+        impl $crate::config::style_edition::StyleEditionDefault for $ty {
+            type ConfigType = $config_ty;
+
+            fn style_edition_default(
+                style_edition: $crate::config::StyleEdition,
+            ) -> Self::ConfigType {
+                match style_edition {
+                    $crate::config::StyleEdition::Edition2015
+                    | $crate::config::StyleEdition::Edition2018
+                    | $crate::config::StyleEdition::Edition2021 => $default_2015,
+                    $crate::config::StyleEdition::Edition2024 => $default_2024,
+                }
+            }
+        }
+    };
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::config::StyleEdition;
+
+    #[test]
+    fn test_impl_default_style_edition_struct_for_all_editions() {
+        struct Unit;
+        style_edition_default!(Unit, usize, _ => 100);
+
+        // regardless of the style edition used the value will always return 100
+        assert_eq!(Unit::style_edition_default(StyleEdition::Edition2015), 100);
+        assert_eq!(Unit::style_edition_default(StyleEdition::Edition2018), 100);
+        assert_eq!(Unit::style_edition_default(StyleEdition::Edition2021), 100);
+        assert_eq!(Unit::style_edition_default(StyleEdition::Edition2024), 100);
+    }
+
+    #[test]
+    fn test_impl_default_style_edition_for_old_and_new_editions() {
+        struct Unit;
+        style_edition_default!(Unit, usize, Edition2024 => 50, _ => 100);
+
+        // style edition 2015-2021 are all the same
+        assert_eq!(Unit::style_edition_default(StyleEdition::Edition2015), 100);
+        assert_eq!(Unit::style_edition_default(StyleEdition::Edition2018), 100);
+        assert_eq!(Unit::style_edition_default(StyleEdition::Edition2021), 100);
+
+        // style edition 2024
+        assert_eq!(Unit::style_edition_default(StyleEdition::Edition2024), 50);
+    }
+}
diff --git a/src/items.rs b/src/items.rs
index a4256730f19..5d01a2df068 100644
--- a/src/items.rs
+++ b/src/items.rs
@@ -832,13 +832,15 @@ pub(crate) fn format_impl(
 
     if is_impl_single_line(context, items.as_slice(), &result, &where_clause_str, item)? {
         result.push_str(&where_clause_str);
-        if where_clause_str.contains('\n') || last_line_contains_single_line_comment(&result) {
-            // if the where_clause contains extra comments AND
-            // there is only one where-clause predicate
-            // recover the suppressed comma in single line where_clause formatting
+        if where_clause_str.contains('\n') {
+            // If there is only one where-clause predicate
+            // and the where-clause spans multiple lines,
+            // then recover the suppressed comma in single line where-clause formatting
             if generics.where_clause.predicates.len() == 1 {
                 result.push(',');
             }
+        }
+        if where_clause_str.contains('\n') || last_line_contains_single_line_comment(&result) {
             result.push_str(&format!("{sep}{{{sep}}}"));
         } else {
             result.push_str(" {}");
diff --git a/src/lib.rs b/src/lib.rs
index 877d057a34b..8800e200fa4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,7 +3,6 @@
 #![warn(unreachable_pub)]
 #![recursion_limit = "256"]
 #![allow(clippy::match_like_matches_macro)]
-#![allow(unreachable_pub)]
 
 #[cfg(test)]
 #[macro_use]
diff --git a/src/matches.rs b/src/matches.rs
index ef509b56837..e6692d78161 100644
--- a/src/matches.rs
+++ b/src/matches.rs
@@ -451,8 +451,8 @@ fn rewrite_match_body(
             };
 
         let block_sep = match context.config.control_brace_style() {
-            ControlBraceStyle::AlwaysNextLine => format!("{}{}", alt_block_sep, body_prefix),
             _ if body_prefix.is_empty() => "".to_owned(),
+            ControlBraceStyle::AlwaysNextLine => format!("{}{}", alt_block_sep, body_prefix),
             _ if forbid_same_line || !arrow_comment.is_empty() => {
                 format!("{}{}", alt_block_sep, body_prefix)
             }
diff --git a/tests/rustfmt/main.rs b/tests/rustfmt/main.rs
index 7dcf7c8416e..87b55ca1d1d 100644
--- a/tests/rustfmt/main.rs
+++ b/tests/rustfmt/main.rs
@@ -184,3 +184,19 @@ fn dont_emit_ICE() {
         assert!(!stderr.contains("thread 'main' panicked"));
     }
 }
+
+#[test]
+fn rustfmt_emits_error_when_control_brace_style_is_always_next_line() {
+    // See also https://github.com/rust-lang/rustfmt/issues/5912
+    let args = [
+        "--config=color=Never",
+        "--config",
+        "control_brace_style=AlwaysNextLine",
+        "--config",
+        "match_arm_blocks=false",
+        "tests/target/issue_5912.rs",
+    ];
+
+    let (_stdout, stderr) = rustfmt(&args);
+    assert!(!stderr.contains("error[internal]: left behind trailing whitespace"))
+}
diff --git a/tests/source/issue_5912.rs b/tests/source/issue_5912.rs
new file mode 100644
index 00000000000..2265fd2146c
--- /dev/null
+++ b/tests/source/issue_5912.rs
@@ -0,0 +1,15 @@
+// rustfmt-match_arm_blocks: false
+// rustfmt-control_brace_style: AlwaysNextLine
+
+fn foo() {
+    match 0 {
+        0 => {
+            aaaaaaaaaaaaaaaaaaaaaaaa
+                + bbbbbbbbbbbbbbbbbbbbbbbbb
+                + bbbbbbbbbbbbbbbbbbbbbbbbb
+                + bbbbbbbbbbbbbbbbbbbbbbbbb
+                + bbbbbbbbbbbbbbbbbbbbbbbbb
+        }
+        _ => 2,
+    }
+}
diff --git a/tests/target/impl.rs b/tests/target/impl.rs
index f37fbcf1fcb..10de0ecde56 100644
--- a/tests/target/impl.rs
+++ b/tests/target/impl.rs
@@ -32,6 +32,11 @@ where
 {
 }
 
+// #5941
+impl T where (): Clone // Should not add comma to comment
+{
+}
+
 // #1823
 default impl Trait for X {}
 default unsafe impl Trait for Y {}
diff --git a/tests/target/issue_5912.rs b/tests/target/issue_5912.rs
new file mode 100644
index 00000000000..835f2aba971
--- /dev/null
+++ b/tests/target/issue_5912.rs
@@ -0,0 +1,15 @@
+// rustfmt-match_arm_blocks: false
+// rustfmt-control_brace_style: AlwaysNextLine
+
+fn foo() {
+    match 0
+    {
+        0 =>
+            aaaaaaaaaaaaaaaaaaaaaaaa
+                + bbbbbbbbbbbbbbbbbbbbbbbbb
+                + bbbbbbbbbbbbbbbbbbbbbbbbb
+                + bbbbbbbbbbbbbbbbbbbbbbbbb
+                + bbbbbbbbbbbbbbbbbbbbbbbbb,
+        _ => 2,
+    }
+}