Move some utils to clippy_utils::source module

5 files changed, 429 insertions, 416 deletions

diff --git a/clippy_utils/src/hir_utils.rs b/clippy_utils/src/hir_utils.rs
index e28ad27d9a6..4c13a185d5d 100644
--- a/clippy_utils/src/hir_utils.rs
+++ b/clippy_utils/src/hir_utils.rs
@@ -1,5 +1,6 @@
 use crate::consts::{constant_context, constant_simple};
-use crate::{differing_macro_contexts, snippet_opt};
+use crate::differing_macro_contexts;
+use crate::source::snippet_opt;
 use rustc_ast::ast::InlineAsmTemplatePiece;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs
index 366962d8b77..d895d798b5e 100644
--- a/clippy_utils/src/lib.rs
+++ b/clippy_utils/src/lib.rs
@@ -41,6 +41,7 @@ pub mod numeric_literal;
 pub mod paths;
 pub mod ptr;
 pub mod qualify_min_const_fn;
+pub mod source;
 pub mod sugg;
 pub mod ty;
 pub mod usage;
@@ -50,14 +51,12 @@ pub use self::attrs::*;
 pub use self::diagnostics::*;
 pub use self::hir_utils::{both, eq_expr_value, over, SpanlessEq, SpanlessHash};
 
-use std::borrow::Cow;
 use std::collections::hash_map::Entry;
 use std::hash::BuildHasherDefault;
 
 use if_chain::if_chain;
 use rustc_ast::ast::{self, Attribute, BorrowKind, LitKind};
 use rustc_data_structures::fx::FxHashMap;
-use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
@@ -75,11 +74,11 @@ use rustc_middle::ty as rustc_ty;
 use rustc_middle::ty::{layout::IntegerExt, DefIdTree, Ty, TyCtxt, TypeFoldable};
 use rustc_semver::RustcVersion;
 use rustc_session::Session;
-use rustc_span::hygiene::{self, ExpnKind, MacroKind};
+use rustc_span::hygiene::{ExpnKind, MacroKind};
 use rustc_span::source_map::original_sp;
 use rustc_span::sym;
 use rustc_span::symbol::{kw, Ident, Symbol};
-use rustc_span::{BytePos, Pos, Span, SyntaxContext, DUMMY_SP};
+use rustc_span::{Span, DUMMY_SP};
 use rustc_target::abi::Integer;
 use smallvec::SmallVec;
 
@@ -236,20 +235,6 @@ pub fn in_macro(span: Span) -> bool {
     }
 }
 
-// If the snippet is empty, it's an attribute that was inserted during macro
-// expansion and we want to ignore those, because they could come from external
-// sources that the user has no control over.
-// For some reason these attributes don't have any expansion info on them, so
-// we have to check it this way until there is a better way.
-pub fn is_present_in_source<T: LintContext>(cx: &T, span: Span) -> bool {
-    if let Some(snippet) = snippet_opt(cx, span) {
-        if snippet.is_empty() {
-            return false;
-        }
-    }
-    true
-}
-
 /// Checks if given pattern is a wildcard (`_`)
 pub fn is_wild<'tcx>(pat: &impl std::ops::Deref<Target = Pat<'tcx>>) -> bool {
     matches!(pat.kind, PatKind::Wild)
@@ -713,211 +698,6 @@ pub fn find_macro_calls(names: &[&str], body: &Body<'_>) -> Vec<Span> {
     fmc.result
 }
 
-/// Converts a span to a code snippet if available, otherwise use default.
-///
-/// This is useful if you want to provide suggestions for your lint or more generally, if you want
-/// to convert a given `Span` to a `str`.
-///
-/// # Example
-/// ```rust,ignore
-/// snippet(cx, expr.span, "..")
-/// ```
-pub fn snippet<'a, T: LintContext>(cx: &T, span: Span, default: &'a str) -> Cow<'a, str> {
-    snippet_opt(cx, span).map_or_else(|| Cow::Borrowed(default), From::from)
-}
-
-/// Same as `snippet`, but it adapts the applicability level by following rules:
-///
-/// - Applicability level `Unspecified` will never be changed.
-/// - If the span is inside a macro, change the applicability level to `MaybeIncorrect`.
-/// - If the default value is used and the applicability level is `MachineApplicable`, change it to
-/// `HasPlaceholders`
-pub fn snippet_with_applicability<'a, T: LintContext>(
-    cx: &T,
-    span: Span,
-    default: &'a str,
-    applicability: &mut Applicability,
-) -> Cow<'a, str> {
-    if *applicability != Applicability::Unspecified && span.from_expansion() {
-        *applicability = Applicability::MaybeIncorrect;
-    }
-    snippet_opt(cx, span).map_or_else(
-        || {
-            if *applicability == Applicability::MachineApplicable {
-                *applicability = Applicability::HasPlaceholders;
-            }
-            Cow::Borrowed(default)
-        },
-        From::from,
-    )
-}
-
-/// Same as `snippet`, but should only be used when it's clear that the input span is
-/// not a macro argument.
-pub fn snippet_with_macro_callsite<'a, T: LintContext>(cx: &T, span: Span, default: &'a str) -> Cow<'a, str> {
-    snippet(cx, span.source_callsite(), default)
-}
-
-/// Converts a span to a code snippet. Returns `None` if not available.
-pub fn snippet_opt<T: LintContext>(cx: &T, span: Span) -> Option<String> {
-    cx.sess().source_map().span_to_snippet(span).ok()
-}
-
-/// Converts a span (from a block) to a code snippet if available, otherwise use default.
-///
-/// This trims the code of indentation, except for the first line. Use it for blocks or block-like
-/// things which need to be printed as such.
-///
-/// The `indent_relative_to` arg can be used, to provide a span, where the indentation of the
-/// resulting snippet of the given span.
-///
-/// # Example
-///
-/// ```rust,ignore
-/// snippet_block(cx, block.span, "..", None)
-/// // where, `block` is the block of the if expr
-///     if x {
-///         y;
-///     }
-/// // will return the snippet
-/// {
-///     y;
-/// }
-/// ```
-///
-/// ```rust,ignore
-/// snippet_block(cx, block.span, "..", Some(if_expr.span))
-/// // where, `block` is the block of the if expr
-///     if x {
-///         y;
-///     }
-/// // will return the snippet
-/// {
-///         y;
-///     } // aligned with `if`
-/// ```
-/// Note that the first line of the snippet always has 0 indentation.
-pub fn snippet_block<'a, T: LintContext>(
-    cx: &T,
-    span: Span,
-    default: &'a str,
-    indent_relative_to: Option<Span>,
-) -> Cow<'a, str> {
-    let snip = snippet(cx, span, default);
-    let indent = indent_relative_to.and_then(|s| indent_of(cx, s));
-    reindent_multiline(snip, true, indent)
-}
-
-/// Same as `snippet_block`, but adapts the applicability level by the rules of
-/// `snippet_with_applicability`.
-pub fn snippet_block_with_applicability<'a, T: LintContext>(
-    cx: &T,
-    span: Span,
-    default: &'a str,
-    indent_relative_to: Option<Span>,
-    applicability: &mut Applicability,
-) -> Cow<'a, str> {
-    let snip = snippet_with_applicability(cx, span, default, applicability);
-    let indent = indent_relative_to.and_then(|s| indent_of(cx, s));
-    reindent_multiline(snip, true, indent)
-}
-
-/// Same as `snippet_with_applicability`, but first walks the span up to the given context. This
-/// will result in the macro call, rather then the expansion, if the span is from a child context.
-/// If the span is not from a child context, it will be used directly instead.
-///
-/// e.g. Given the expression `&vec![]`, getting a snippet from the span for `vec![]` as a HIR node
-/// would result in `box []`. If given the context of the address of expression, this function will
-/// correctly get a snippet of `vec![]`.
-///
-/// This will also return whether or not the snippet is a macro call.
-pub fn snippet_with_context(
-    cx: &LateContext<'_>,
-    span: Span,
-    outer: SyntaxContext,
-    default: &'a str,
-    applicability: &mut Applicability,
-) -> (Cow<'a, str>, bool) {
-    let outer_span = hygiene::walk_chain(span, outer);
-    let (span, is_macro_call) = if outer_span.ctxt() == outer {
-        (outer_span, span.ctxt() != outer)
-    } else {
-        // The span is from a macro argument, and the outer context is the macro using the argument
-        if *applicability != Applicability::Unspecified {
-            *applicability = Applicability::MaybeIncorrect;
-        }
-        // TODO: get the argument span.
-        (span, false)
-    };
-
-    (
-        snippet_with_applicability(cx, span, default, applicability),
-        is_macro_call,
-    )
-}
-
-/// Returns a new Span that extends the original Span to the first non-whitespace char of the first
-/// line.
-///
-/// ```rust,ignore
-///     let x = ();
-/// //          ^^
-/// // will be converted to
-///     let x = ();
-/// //  ^^^^^^^^^^
-/// ```
-pub fn first_line_of_span<T: LintContext>(cx: &T, span: Span) -> Span {
-    first_char_in_first_line(cx, span).map_or(span, |first_char_pos| span.with_lo(first_char_pos))
-}
-
-fn first_char_in_first_line<T: LintContext>(cx: &T, span: Span) -> Option<BytePos> {
-    let line_span = line_span(cx, span);
-    snippet_opt(cx, line_span).and_then(|snip| {
-        snip.find(|c: char| !c.is_whitespace())
-            .map(|pos| line_span.lo() + BytePos::from_usize(pos))
-    })
-}
-
-/// Returns the indentation of the line of a span
-///
-/// ```rust,ignore
-/// let x = ();
-/// //      ^^ -- will return 0
-///     let x = ();
-/// //          ^^ -- will return 4
-/// ```
-pub fn indent_of<T: LintContext>(cx: &T, span: Span) -> Option<usize> {
-    snippet_opt(cx, line_span(cx, span)).and_then(|snip| snip.find(|c: char| !c.is_whitespace()))
-}
-
-/// Returns the positon just before rarrow
-///
-/// ```rust,ignore
-/// fn into(self) -> () {}
-///              ^
-/// // in case of unformatted code
-/// fn into2(self)-> () {}
-///               ^
-/// fn into3(self)   -> () {}
-///               ^
-/// ```
-pub fn position_before_rarrow(s: &str) -> Option<usize> {
-    s.rfind("->").map(|rpos| {
-        let mut rpos = rpos;
-        let chars: Vec<char> = s.chars().collect();
-        while rpos > 1 {
-            if let Some(c) = chars.get(rpos - 1) {
-                if c.is_whitespace() {
-                    rpos -= 1;
-                    continue;
-                }
-            }
-            break;
-        }
-        rpos
-    })
-}
-
 /// Extends the span to the beginning of the spans line, incl. whitespaces.
 ///
 /// ```rust,ignore
@@ -935,66 +715,6 @@ fn line_span<T: LintContext>(cx: &T, span: Span) -> Span {
     Span::new(line_start, span.hi(), span.ctxt())
 }
 
-/// Like `snippet_block`, but add braces if the expr is not an `ExprKind::Block`.
-/// Also takes an `Option<String>` which can be put inside the braces.
-pub fn expr_block<'a, T: LintContext>(
-    cx: &T,
-    expr: &Expr<'_>,
-    option: Option<String>,
-    default: &'a str,
-    indent_relative_to: Option<Span>,
-) -> Cow<'a, str> {
-    let code = snippet_block(cx, expr.span, default, indent_relative_to);
-    let string = option.unwrap_or_default();
-    if expr.span.from_expansion() {
-        Cow::Owned(format!("{{ {} }}", snippet_with_macro_callsite(cx, expr.span, default)))
-    } else if let ExprKind::Block(_, _) = expr.kind {
-        Cow::Owned(format!("{}{}", code, string))
-    } else if string.is_empty() {
-        Cow::Owned(format!("{{ {} }}", code))
-    } else {
-        Cow::Owned(format!("{{\n{};\n{}\n}}", code, string))
-    }
-}
-
-/// Reindent a multiline string with possibility of ignoring the first line.
-#[allow(clippy::needless_pass_by_value)]
-pub fn reindent_multiline(s: Cow<'_, str>, ignore_first: bool, indent: Option<usize>) -> Cow<'_, str> {
-    let s_space = reindent_multiline_inner(&s, ignore_first, indent, ' ');
-    let s_tab = reindent_multiline_inner(&s_space, ignore_first, indent, '\t');
-    reindent_multiline_inner(&s_tab, ignore_first, indent, ' ').into()
-}
-
-fn reindent_multiline_inner(s: &str, ignore_first: bool, indent: Option<usize>, ch: char) -> String {
-    let x = s
-        .lines()
-        .skip(ignore_first as usize)
-        .filter_map(|l| {
-            if l.is_empty() {
-                None
-            } else {
-                // ignore empty lines
-                Some(l.char_indices().find(|&(_, x)| x != ch).unwrap_or((l.len(), ch)).0)
-            }
-        })
-        .min()
-        .unwrap_or(0);
-    let indent = indent.unwrap_or(0);
-    s.lines()
-        .enumerate()
-        .map(|(i, l)| {
-            if (ignore_first && i == 0) || l.is_empty() {
-                l.to_owned()
-            } else if x > indent {
-                l.split_at(x - indent).1.to_owned()
-            } else {
-                " ".repeat(indent - x) + l
-            }
-        })
-        .collect::<Vec<String>>()
-        .join("\n")
-}
-
 /// Gets the span of the node, if there is one.
 pub fn get_node_span(node: Node<'_>) -> Option<Span> {
     match node {
@@ -1366,39 +1086,6 @@ pub fn clip(tcx: TyCtxt<'_>, u: u128, ity: rustc_ty::UintTy) -> u128 {
     (u << amt) >> amt
 }
 
-/// Removes block comments from the given `Vec` of lines.
-///
-/// # Examples
-///
-/// ```rust,ignore
-/// without_block_comments(vec!["/*", "foo", "*/"]);
-/// // => vec![]
-///
-/// without_block_comments(vec!["bar", "/*", "foo", "*/"]);
-/// // => vec!["bar"]
-/// ```
-pub fn without_block_comments(lines: Vec<&str>) -> Vec<&str> {
-    let mut without = vec![];
-
-    let mut nest_level = 0;
-
-    for line in lines {
-        if line.contains("/*") {
-            nest_level += 1;
-            continue;
-        } else if line.contains("*/") {
-            nest_level -= 1;
-            continue;
-        }
-
-        if nest_level == 0 {
-            without.push(line);
-        }
-    }
-
-    without
-}
-
 pub fn any_parent_is_automatically_derived(tcx: TyCtxt<'_>, node: HirId) -> bool {
     let map = &tcx.hir();
     let mut prev_enclosing_node = None;
@@ -1777,100 +1464,3 @@ pub fn is_some_ctor(cx: &LateContext<'_>, res: Res) -> bool {
     }
     false
 }
-
-#[cfg(test)]
-mod test {
-    use super::{reindent_multiline, without_block_comments};
-
-    #[test]
-    fn test_reindent_multiline_single_line() {
-        assert_eq!("", reindent_multiline("".into(), false, None));
-        assert_eq!("...", reindent_multiline("...".into(), false, None));
-        assert_eq!("...", reindent_multiline("    ...".into(), false, None));
-        assert_eq!("...", reindent_multiline("\t...".into(), false, None));
-        assert_eq!("...", reindent_multiline("\t\t...".into(), false, None));
-    }
-
-    #[test]
-    #[rustfmt::skip]
-    fn test_reindent_multiline_block() {
-        assert_eq!("\
-    if x {
-        y
-    } else {
-        z
-    }", reindent_multiline("    if x {
-            y
-        } else {
-            z
-        }".into(), false, None));
-        assert_eq!("\
-    if x {
-    \ty
-    } else {
-    \tz
-    }", reindent_multiline("    if x {
-        \ty
-        } else {
-        \tz
-        }".into(), false, None));
-    }
-
-    #[test]
-    #[rustfmt::skip]
-    fn test_reindent_multiline_empty_line() {
-        assert_eq!("\
-    if x {
-        y
-
-    } else {
-        z
-    }", reindent_multiline("    if x {
-            y
-
-        } else {
-            z
-        }".into(), false, None));
-    }
-
-    #[test]
-    #[rustfmt::skip]
-    fn test_reindent_multiline_lines_deeper() {
-        assert_eq!("\
-        if x {
-            y
-        } else {
-            z
-        }", reindent_multiline("\
-    if x {
-        y
-    } else {
-        z
-    }".into(), true, Some(8)));
-    }
-
-    #[test]
-    fn test_without_block_comments_lines_without_block_comments() {
-        let result = without_block_comments(vec!["/*", "", "*/"]);
-        println!("result: {:?}", result);
-        assert!(result.is_empty());
-
-        let result = without_block_comments(vec!["", "/*", "", "*/", "#[crate_type = \"lib\"]", "/*", "", "*/", ""]);
-        assert_eq!(result, vec!["", "#[crate_type = \"lib\"]", ""]);
-
-        let result = without_block_comments(vec!["/* rust", "", "*/"]);
-        assert!(result.is_empty());
-
-        let result = without_block_comments(vec!["/* one-line comment */"]);
-        assert!(result.is_empty());
-
-        let result = without_block_comments(vec!["/* nested", "/* multi-line", "comment", "*/", "test", "*/"]);
-        assert!(result.is_empty());
-
-        let result = without_block_comments(vec!["/* nested /* inline /* comment */ test */ */"]);
-        assert!(result.is_empty());
-
-        let result = without_block_comments(vec!["foo", "bar", "baz"]);
-        assert_eq!(result, vec!["foo", "bar", "baz"]);
-    }
-}
diff --git a/clippy_utils/src/ptr.rs b/clippy_utils/src/ptr.rs
index df6143edbca..5885cc83560 100644
--- a/clippy_utils/src/ptr.rs
+++ b/clippy_utils/src/ptr.rs
@@ -1,4 +1,5 @@
-use crate::{get_pat_name, match_var, snippet};
+use crate::source::snippet;
+use crate::{get_pat_name, match_var};
 use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
 use rustc_hir::{Body, BodyId, Expr, ExprKind, Param};
 use rustc_lint::LateContext;
diff --git a/clippy_utils/src/source.rs b/clippy_utils/src/source.rs
new file mode 100644
index 00000000000..2d794d48dc5
--- /dev/null
+++ b/clippy_utils/src/source.rs
@@ -0,0 +1,420 @@
+//! Utils for extracting, inspecting or transforming source code
+
+#![allow(clippy::module_name_repetitions)]
+
+use crate::line_span;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LintContext};
+use rustc_span::hygiene;
+use rustc_span::{BytePos, Pos, Span, SyntaxContext};
+use std::borrow::Cow;
+
+/// Like `snippet_block`, but add braces if the expr is not an `ExprKind::Block`.
+/// Also takes an `Option<String>` which can be put inside the braces.
+pub fn expr_block<'a, T: LintContext>(
+    cx: &T,
+    expr: &Expr<'_>,
+    option: Option<String>,
+    default: &'a str,
+    indent_relative_to: Option<Span>,
+) -> Cow<'a, str> {
+    let code = snippet_block(cx, expr.span, default, indent_relative_to);
+    let string = option.unwrap_or_default();
+    if expr.span.from_expansion() {
+        Cow::Owned(format!("{{ {} }}", snippet_with_macro_callsite(cx, expr.span, default)))
+    } else if let ExprKind::Block(_, _) = expr.kind {
+        Cow::Owned(format!("{}{}", code, string))
+    } else if string.is_empty() {
+        Cow::Owned(format!("{{ {} }}", code))
+    } else {
+        Cow::Owned(format!("{{\n{};\n{}\n}}", code, string))
+    }
+}
+
+/// Returns a new Span that extends the original Span to the first non-whitespace char of the first
+/// line.
+///
+/// ```rust,ignore
+///     let x = ();
+/// //          ^^
+/// // will be converted to
+///     let x = ();
+/// //  ^^^^^^^^^^
+/// ```
+pub fn first_line_of_span<T: LintContext>(cx: &T, span: Span) -> Span {
+    first_char_in_first_line(cx, span).map_or(span, |first_char_pos| span.with_lo(first_char_pos))
+}
+
+fn first_char_in_first_line<T: LintContext>(cx: &T, span: Span) -> Option<BytePos> {
+    let line_span = line_span(cx, span);
+    snippet_opt(cx, line_span).and_then(|snip| {
+        snip.find(|c: char| !c.is_whitespace())
+            .map(|pos| line_span.lo() + BytePos::from_usize(pos))
+    })
+}
+
+/// Returns the indentation of the line of a span
+///
+/// ```rust,ignore
+/// let x = ();
+/// //      ^^ -- will return 0
+///     let x = ();
+/// //          ^^ -- will return 4
+/// ```
+pub fn indent_of<T: LintContext>(cx: &T, span: Span) -> Option<usize> {
+    snippet_opt(cx, line_span(cx, span)).and_then(|snip| snip.find(|c: char| !c.is_whitespace()))
+}
+
+// If the snippet is empty, it's an attribute that was inserted during macro
+// expansion and we want to ignore those, because they could come from external
+// sources that the user has no control over.
+// For some reason these attributes don't have any expansion info on them, so
+// we have to check it this way until there is a better way.
+pub fn is_present_in_source<T: LintContext>(cx: &T, span: Span) -> bool {
+    if let Some(snippet) = snippet_opt(cx, span) {
+        if snippet.is_empty() {
+            return false;
+        }
+    }
+    true
+}
+
+/// Returns the positon just before rarrow
+///
+/// ```rust,ignore
+/// fn into(self) -> () {}
+///              ^
+/// // in case of unformatted code
+/// fn into2(self)-> () {}
+///               ^
+/// fn into3(self)   -> () {}
+///               ^
+/// ```
+pub fn position_before_rarrow(s: &str) -> Option<usize> {
+    s.rfind("->").map(|rpos| {
+        let mut rpos = rpos;
+        let chars: Vec<char> = s.chars().collect();
+        while rpos > 1 {
+            if let Some(c) = chars.get(rpos - 1) {
+                if c.is_whitespace() {
+                    rpos -= 1;
+                    continue;
+                }
+            }
+            break;
+        }
+        rpos
+    })
+}
+
+/// Reindent a multiline string with possibility of ignoring the first line.
+#[allow(clippy::needless_pass_by_value)]
+pub fn reindent_multiline(s: Cow<'_, str>, ignore_first: bool, indent: Option<usize>) -> Cow<'_, str> {
+    let s_space = reindent_multiline_inner(&s, ignore_first, indent, ' ');
+    let s_tab = reindent_multiline_inner(&s_space, ignore_first, indent, '\t');
+    reindent_multiline_inner(&s_tab, ignore_first, indent, ' ').into()
+}
+
+fn reindent_multiline_inner(s: &str, ignore_first: bool, indent: Option<usize>, ch: char) -> String {
+    let x = s
+        .lines()
+        .skip(ignore_first as usize)
+        .filter_map(|l| {
+            if l.is_empty() {
+                None
+            } else {
+                // ignore empty lines
+                Some(l.char_indices().find(|&(_, x)| x != ch).unwrap_or((l.len(), ch)).0)
+            }
+        })
+        .min()
+        .unwrap_or(0);
+    let indent = indent.unwrap_or(0);
+    s.lines()
+        .enumerate()
+        .map(|(i, l)| {
+            if (ignore_first && i == 0) || l.is_empty() {
+                l.to_owned()
+            } else if x > indent {
+                l.split_at(x - indent).1.to_owned()
+            } else {
+                " ".repeat(indent - x) + l
+            }
+        })
+        .collect::<Vec<String>>()
+        .join("\n")
+}
+
+/// Converts a span to a code snippet if available, otherwise use default.
+///
+/// This is useful if you want to provide suggestions for your lint or more generally, if you want
+/// to convert a given `Span` to a `str`.
+///
+/// # Example
+/// ```rust,ignore
+/// snippet(cx, expr.span, "..")
+/// ```
+pub fn snippet<'a, T: LintContext>(cx: &T, span: Span, default: &'a str) -> Cow<'a, str> {
+    snippet_opt(cx, span).map_or_else(|| Cow::Borrowed(default), From::from)
+}
+
+/// Same as `snippet`, but it adapts the applicability level by following rules:
+///
+/// - Applicability level `Unspecified` will never be changed.
+/// - If the span is inside a macro, change the applicability level to `MaybeIncorrect`.
+/// - If the default value is used and the applicability level is `MachineApplicable`, change it to
+/// `HasPlaceholders`
+pub fn snippet_with_applicability<'a, T: LintContext>(
+    cx: &T,
+    span: Span,
+    default: &'a str,
+    applicability: &mut Applicability,
+) -> Cow<'a, str> {
+    if *applicability != Applicability::Unspecified && span.from_expansion() {
+        *applicability = Applicability::MaybeIncorrect;
+    }
+    snippet_opt(cx, span).map_or_else(
+        || {
+            if *applicability == Applicability::MachineApplicable {
+                *applicability = Applicability::HasPlaceholders;
+            }
+            Cow::Borrowed(default)
+        },
+        From::from,
+    )
+}
+
+/// Same as `snippet`, but should only be used when it's clear that the input span is
+/// not a macro argument.
+pub fn snippet_with_macro_callsite<'a, T: LintContext>(cx: &T, span: Span, default: &'a str) -> Cow<'a, str> {
+    snippet(cx, span.source_callsite(), default)
+}
+
+/// Converts a span to a code snippet. Returns `None` if not available.
+pub fn snippet_opt<T: LintContext>(cx: &T, span: Span) -> Option<String> {
+    cx.sess().source_map().span_to_snippet(span).ok()
+}
+
+/// Converts a span (from a block) to a code snippet if available, otherwise use default.
+///
+/// This trims the code of indentation, except for the first line. Use it for blocks or block-like
+/// things which need to be printed as such.
+///
+/// The `indent_relative_to` arg can be used, to provide a span, where the indentation of the
+/// resulting snippet of the given span.
+///
+/// # Example
+///
+/// ```rust,ignore
+/// snippet_block(cx, block.span, "..", None)
+/// // where, `block` is the block of the if expr
+///     if x {
+///         y;
+///     }
+/// // will return the snippet
+/// {
+///     y;
+/// }
+/// ```
+///
+/// ```rust,ignore
+/// snippet_block(cx, block.span, "..", Some(if_expr.span))
+/// // where, `block` is the block of the if expr
+///     if x {
+///         y;
+///     }
+/// // will return the snippet
+/// {
+///         y;
+///     } // aligned with `if`
+/// ```
+/// Note that the first line of the snippet always has 0 indentation.
+pub fn snippet_block<'a, T: LintContext>(
+    cx: &T,
+    span: Span,
+    default: &'a str,
+    indent_relative_to: Option<Span>,
+) -> Cow<'a, str> {
+    let snip = snippet(cx, span, default);
+    let indent = indent_relative_to.and_then(|s| indent_of(cx, s));
+    reindent_multiline(snip, true, indent)
+}
+
+/// Same as `snippet_block`, but adapts the applicability level by the rules of
+/// `snippet_with_applicability`.
+pub fn snippet_block_with_applicability<'a, T: LintContext>(
+    cx: &T,
+    span: Span,
+    default: &'a str,
+    indent_relative_to: Option<Span>,
+    applicability: &mut Applicability,
+) -> Cow<'a, str> {
+    let snip = snippet_with_applicability(cx, span, default, applicability);
+    let indent = indent_relative_to.and_then(|s| indent_of(cx, s));
+    reindent_multiline(snip, true, indent)
+}
+
+/// Same as `snippet_with_applicability`, but first walks the span up to the given context. This
+/// will result in the macro call, rather then the expansion, if the span is from a child context.
+/// If the span is not from a child context, it will be used directly instead.
+///
+/// e.g. Given the expression `&vec![]`, getting a snippet from the span for `vec![]` as a HIR node
+/// would result in `box []`. If given the context of the address of expression, this function will
+/// correctly get a snippet of `vec![]`.
+///
+/// This will also return whether or not the snippet is a macro call.
+pub fn snippet_with_context(
+    cx: &LateContext<'_>,
+    span: Span,
+    outer: SyntaxContext,
+    default: &'a str,
+    applicability: &mut Applicability,
+) -> (Cow<'a, str>, bool) {
+    let outer_span = hygiene::walk_chain(span, outer);
+    let (span, is_macro_call) = if outer_span.ctxt() == outer {
+        (outer_span, span.ctxt() != outer)
+    } else {
+        // The span is from a macro argument, and the outer context is the macro using the argument
+        if *applicability != Applicability::Unspecified {
+            *applicability = Applicability::MaybeIncorrect;
+        }
+        // TODO: get the argument span.
+        (span, false)
+    };
+
+    (
+        snippet_with_applicability(cx, span, default, applicability),
+        is_macro_call,
+    )
+}
+
+/// Removes block comments from the given `Vec` of lines.
+///
+/// # Examples
+///
+/// ```rust,ignore
+/// without_block_comments(vec!["/*", "foo", "*/"]);
+/// // => vec![]
+///
+/// without_block_comments(vec!["bar", "/*", "foo", "*/"]);
+/// // => vec!["bar"]
+/// ```
+pub fn without_block_comments(lines: Vec<&str>) -> Vec<&str> {
+    let mut without = vec![];
+
+    let mut nest_level = 0;
+
+    for line in lines {
+        if line.contains("/*") {
+            nest_level += 1;
+            continue;
+        } else if line.contains("*/") {
+            nest_level -= 1;
+            continue;
+        }
+
+        if nest_level == 0 {
+            without.push(line);
+        }
+    }
+
+    without
+}
+
+#[cfg(test)]
+mod test {
+    use super::{reindent_multiline, without_block_comments};
+
+    #[test]
+    fn test_reindent_multiline_single_line() {
+        assert_eq!("", reindent_multiline("".into(), false, None));
+        assert_eq!("...", reindent_multiline("...".into(), false, None));
+        assert_eq!("...", reindent_multiline("    ...".into(), false, None));
+        assert_eq!("...", reindent_multiline("\t...".into(), false, None));
+        assert_eq!("...", reindent_multiline("\t\t...".into(), false, None));
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn test_reindent_multiline_block() {
+        assert_eq!("\
+    if x {
+        y
+    } else {
+        z
+    }", reindent_multiline("    if x {
+            y
+        } else {
+            z
+        }".into(), false, None));
+        assert_eq!("\
+    if x {
+    \ty
+    } else {
+    \tz
+    }", reindent_multiline("    if x {
+        \ty
+        } else {
+        \tz
+        }".into(), false, None));
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn test_reindent_multiline_empty_line() {
+        assert_eq!("\
+    if x {
+        y
+
+    } else {
+        z
+    }", reindent_multiline("    if x {
+            y
+
+        } else {
+            z
+        }".into(), false, None));
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn test_reindent_multiline_lines_deeper() {
+        assert_eq!("\
+        if x {
+            y
+        } else {
+            z
+        }", reindent_multiline("\
+    if x {
+        y
+    } else {
+        z
+    }".into(), true, Some(8)));
+    }
+
+    #[test]
+    fn test_without_block_comments_lines_without_block_comments() {
+        let result = without_block_comments(vec!["/*", "", "*/"]);
+        println!("result: {:?}", result);
+        assert!(result.is_empty());
+
+        let result = without_block_comments(vec!["", "/*", "", "*/", "#[crate_type = \"lib\"]", "/*", "", "*/", ""]);
+        assert_eq!(result, vec!["", "#[crate_type = \"lib\"]", ""]);
+
+        let result = without_block_comments(vec!["/* rust", "", "*/"]);
+        assert!(result.is_empty());
+
+        let result = without_block_comments(vec!["/* one-line comment */"]);
+        assert!(result.is_empty());
+
+        let result = without_block_comments(vec!["/* nested", "/* multi-line", "comment", "*/", "test", "*/"]);
+        assert!(result.is_empty());
+
+        let result = without_block_comments(vec!["/* nested /* inline /* comment */ test */ */"]);
+        assert!(result.is_empty());
+
+        let result = without_block_comments(vec!["foo", "bar", "baz"]);
+        assert_eq!(result, vec!["foo", "bar", "baz"]);
+    }
+}
diff --git a/clippy_utils/src/sugg.rs b/clippy_utils/src/sugg.rs
index d4f6f4281d3..b2fe4317154 100644
--- a/clippy_utils/src/sugg.rs
+++ b/clippy_utils/src/sugg.rs
@@ -1,7 +1,8 @@
 //! Contains utility functions to generate suggestions.
 #![deny(clippy::missing_docs_in_private_items)]
 
-use crate::{higher, snippet, snippet_opt, snippet_with_macro_callsite};
+use crate::higher;
+use crate::source::{snippet, snippet_opt, snippet_with_macro_callsite};
 use rustc_ast::util::parser::AssocOp;
 use rustc_ast::{ast, token};
 use rustc_ast_pretty::pprust::token_kind_to_string;