Fix clippy warnings (#633)

clippy.toml

@@ -0,0 +1 @@
+msrv = "1.42.0"

src/lib.rs

@@ -26,14 +26,17 @@
 #![warn(ellipsis_inclusive_range_patterns)]
 //#![warn(elided_lifetimes_in_paths)]
 #![warn(explicit_outlives_requirements)]
-// Allow clippy warnings when we aren't building with clippy.
-#![allow(unknown_lints)]
+// Style.
+#![allow(clippy::bool_to_int_with_if)]
+#![allow(clippy::collapsible_else_if)]
+#![allow(clippy::comparison_chain)]
+#![allow(clippy::manual_range_contains)]
+#![allow(clippy::needless_late_init)]
+#![allow(clippy::too_many_arguments)]
 // False positives with `fallible_iterator`.
 #![allow(clippy::should_implement_trait)]
-// Many false positives involving `continue`.
-#![allow(clippy::never_loop)]
-// False positives when block expressions are used inside an assertion.
-#![allow(clippy::panic_params)]
+// False positives.
+#![allow(clippy::derive_partial_eq_without_eq)]
 #![no_std]
 
 #[allow(unused_imports)]

src/read/abbrev.rs

@@ -344,7 +344,7 @@ impl Attributes {
     /// Pushes a new value onto this list of attributes.
     fn push(&mut self, attr: AttributeSpecification) {
         match self {
-            Attributes::Heap(list) => return list.push(attr),
+            Attributes::Heap(list) => list.push(attr),
             Attributes::Inline {
                 buf,
                 len: MAX_ATTRIBUTES_INLINE,
@@ -363,13 +363,13 @@ impl Attributes {
 
 impl Debug for Attributes {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        (&**self).fmt(f)
+        (**self).fmt(f)
     }
 }
 
 impl PartialEq for Attributes {
     fn eq(&self, other: &Attributes) -> bool {
-        &**self == &**other
+        **self == **other
     }
 }
 
@@ -394,7 +394,7 @@ impl FromIterator<AttributeSpecification> for Attributes {
         for item in iter {
             list.push(item);
         }
-        return list;
+        list
     }
 }
 
@@ -504,8 +504,7 @@ pub(crate) fn get_attribute_size(form: constants::DwForm, encoding: Encoding) ->
     match form {
         constants::DW_FORM_addr => Some(encoding.address_size),
 
-        constants::DW_FORM_implicit_const |
-        constants::DW_FORM_flag_present => Some(0),
+        constants::DW_FORM_implicit_const | constants::DW_FORM_flag_present => Some(0),
 
         constants::DW_FORM_data1
         | constants::DW_FORM_flag
@@ -531,7 +530,7 @@ pub(crate) fn get_attribute_size(form: constants::DwForm, encoding: Encoding) ->
         | constants::DW_FORM_ref_sig8
         | constants::DW_FORM_ref_sup8 => Some(8),
 
-        constants::DW_FORM_data16  => Some(16),
+        constants::DW_FORM_data16 => Some(16),
 
         constants::DW_FORM_sec_offset
         | constants::DW_FORM_GNU_ref_alt
@@ -552,16 +551,16 @@ pub(crate) fn get_attribute_size(form: constants::DwForm, encoding: Encoding) ->
         }
 
         // Variably sized forms.
-        constants::DW_FORM_block |
-        constants::DW_FORM_block1 |
-        constants::DW_FORM_block2 |
-        constants::DW_FORM_block4 |
-        constants::DW_FORM_exprloc |
-        constants::DW_FORM_ref_udata |
-        constants::DW_FORM_string |
-        constants::DW_FORM_sdata |
-        constants::DW_FORM_udata |
-        constants::DW_FORM_indirect |
+        constants::DW_FORM_block
+        | constants::DW_FORM_block1
+        | constants::DW_FORM_block2
+        | constants::DW_FORM_block4
+        | constants::DW_FORM_exprloc
+        | constants::DW_FORM_ref_udata
+        | constants::DW_FORM_string
+        | constants::DW_FORM_sdata
+        | constants::DW_FORM_udata
+        | constants::DW_FORM_indirect => None,
 
         // We don't know the size of unknown forms.
         _ => None,

src/read/cfi.rs

@@ -1058,7 +1058,6 @@ where
     Fde(PartialFrameDescriptionEntry<'bases, Section, R>),
 }
 
-#[allow(clippy::type_complexity)]
 fn parse_cfi_entry<'bases, Section, R>(
     bases: &'bases BaseAddresses,
     section: &Section,
@@ -1617,7 +1616,6 @@ where
 }
 
 impl<R: Reader> FrameDescriptionEntry<R> {
-    #[allow(clippy::too_many_arguments)]
     fn parse_rest<Section, F>(
         offset: R::Offset,
         length: R::Offset,
@@ -1982,7 +1980,7 @@ impl<R: Reader, A: UnwindContextStorage<R>> UnwindContext<R, A> {
         }
 
         let mut table = UnwindTable::new_for_cie(section, bases, self, cie);
-        while let Some(_) = table.next_row()? {}
+        while table.next_row()?.is_some() {}
 
         self.save_initial_rules()?;
         Ok(())
@@ -2005,7 +2003,7 @@ impl<R: Reader, A: UnwindContextStorage<R>> UnwindContext<R, A> {
     }
 
     fn save_initial_rules(&mut self) -> Result<()> {
-        assert_eq!(self.is_initialized, false);
+        debug_assert!(!self.is_initialized);
         self.initial_rule = match *self.stack.last().unwrap().registers.rules {
             // All rules are default (undefined). In this case just synthesize
             // an undefined rule.
@@ -2821,10 +2819,7 @@ pub enum RegisterRule<R: Reader> {
 
 impl<R: Reader> RegisterRule<R> {
     fn is_defined(&self) -> bool {
-        match *self {
-            RegisterRule::Undefined => false,
-            _ => true,
-        }
+        !matches!(*self, RegisterRule::Undefined)
     }
 }
 
@@ -3394,10 +3389,10 @@ impl Default for Pointer {
     }
 }
 
-impl Into<u64> for Pointer {
+impl From<Pointer> for u64 {
     #[inline]
-    fn into(self) -> u64 {
-        match self {
+    fn from(p: Pointer) -> u64 {
+        match p {
             Pointer::Direct(p) | Pointer::Indirect(p) => p,
         }
     }
@@ -3762,8 +3757,6 @@ mod tests {
         }
     }
 
-    #[allow(clippy::type_complexity)]
-    #[allow(clippy::needless_pass_by_value)]
     fn assert_parse_cie<'input, E>(
         kind: SectionKind<DebugFrame<EndianSlice<'input, E>>>,
         section: Section,
@@ -5118,7 +5111,6 @@ mod tests {
         assert_eq!(iter.next(), Ok(None));
     }
 
-    #[allow(clippy::needless_pass_by_value)]
     fn assert_eval<'a, I>(
         mut initial_ctx: UnwindContext<EndianSlice<'a, LittleEndian>>,
         expected_ctx: UnwindContext<EndianSlice<'a, LittleEndian>>,
@@ -5598,7 +5590,6 @@ mod tests {
 
     #[test]
     fn test_unwind_table_cie_no_rule() {
-        #[allow(clippy::identity_op)]
         let initial_instructions = Section::with_endian(Endian::Little)
             // The CFA is -12 from register 4.
             .D8(constants::DW_CFA_def_cfa_sf.0)
@@ -5671,7 +5662,6 @@ mod tests {
 
     #[test]
     fn test_unwind_table_cie_single_rule() {
-        #[allow(clippy::identity_op)]
         let initial_instructions = Section::with_endian(Endian::Little)
             // The CFA is -12 from register 4.
             .D8(constants::DW_CFA_def_cfa_sf.0)
@@ -5747,7 +5737,6 @@ mod tests {
 
     #[test]
     fn test_unwind_table_next_row() {
-        #[allow(clippy::identity_op)]
         let initial_instructions = Section::with_endian(Endian::Little)
             // The CFA is -12 from register 4.
             .D8(constants::DW_CFA_def_cfa_sf.0)

src/read/endian_slice.rs

@@ -197,12 +197,12 @@ where
     }
 }
 
-impl<'input, Endian> Into<&'input [u8]> for EndianSlice<'input, Endian>
+impl<'input, Endian> From<EndianSlice<'input, Endian>> for &'input [u8]
 where
     Endian: Endianity,
 {
-    fn into(self) -> &'input [u8] {
-        self.slice
+    fn from(endian_slice: EndianSlice<'input, Endian>) -> &'input [u8] {
+        endian_slice.slice
     }
 }
 

src/read/line.rs

@@ -198,7 +198,6 @@ where
     R: Reader<Offset = Offset>,
     Offset: ReaderOffset,
 {
-    #[allow(clippy::new_ret_no_self)]
     fn new(program: IncompleteLineProgram<R, Offset>) -> OneShotLineRows<R, Offset> {
         let row = LineRow::new(program.header());
         let instructions = LineInstructions {
@@ -606,7 +605,6 @@ impl<R: Reader> LineInstructions<R> {
     ///
     /// Unfortunately, the `header` parameter means that this cannot be a
     /// `FallibleIterator`.
-    #[allow(clippy::inline_always)]
     #[inline(always)]
     pub fn next_instruction(
         &mut self,

src/read/loclists.rs

@@ -233,7 +233,7 @@ impl<R: Reader> LocationLists<R> {
         let (mut input, format) = if unit_encoding.version <= 4 {
             (self.debug_loc.section.clone(), LocListsFormat::Bare)
         } else {
-            (self.debug_loclists.section.clone(), LocListsFormat::LLE)
+            (self.debug_loclists.section.clone(), LocListsFormat::Lle)
         };
         input.skip(offset.0)?;
         Ok(RawLocListIter::new(input, unit_encoding, format))
@@ -259,7 +259,7 @@ impl<R: Reader> LocationLists<R> {
         Ok(RawLocListIter::new(
             input,
             unit_encoding,
-            LocListsFormat::LLE,
+            LocListsFormat::Lle,
         ))
     }
 
@@ -300,7 +300,7 @@ enum LocListsFormat {
     Bare,
     /// The DW_LLE encoded range list format used in DWARF 5 and the non-standard GNU
     /// split dwarf extension.
-    LLE,
+    Lle,
 }
 
 /// A raw iterator over a location list.
@@ -402,10 +402,10 @@ fn parse_data<R: Reader>(input: &mut R, encoding: Encoding) -> Result<Expression
 impl<R: Reader> RawLocListEntry<R> {
     /// Parse a location list entry from `.debug_loclists`
     fn parse(input: &mut R, encoding: Encoding, format: LocListsFormat) -> Result<Option<Self>> {
-        match format {
+        Ok(match format {
             LocListsFormat::Bare => {
                 let range = RawRange::parse(input, encoding.address_size)?;
-                return Ok(if range.is_end() {
+                if range.is_end() {
                     None
                 } else if range.is_base_address(encoding.address_size) {
                     Some(RawLocListEntry::BaseAddress { addr: range.end })
@@ -417,9 +417,9 @@ impl<R: Reader> RawLocListEntry<R> {
                         end: range.end,
                         data,
                     })
-                });
+                }
             }
-            LocListsFormat::LLE => Ok(match constants::DwLle(input.read_u8()?) {
+            LocListsFormat::Lle => match constants::DwLle(input.read_u8()?) {
                 constants::DW_LLE_end_of_list => None,
                 constants::DW_LLE_base_addressx => Some(RawLocListEntry::BaseAddressx {
                     addr: DebugAddrIndex(input.read_uleb128().and_then(R::Offset::from_u64)?),
@@ -463,8 +463,8 @@ impl<R: Reader> RawLocListEntry<R> {
                 _ => {
                     return Err(Error::InvalidAddressRange);
                 }
-            }),
-        }
+            },
+        })
     }
 }
 

src/read/op.rs

@@ -346,10 +346,7 @@ where
 {
     /// Return true if the piece is empty.
     pub fn is_empty(&self) -> bool {
-        match *self {
-            Location::Empty => true,
-            _ => false,
-        }
+        matches!(*self, Location::Empty)
     }
 }
 
@@ -1225,7 +1222,6 @@ impl<R: Reader, S: EvaluationStorage<R>> Evaluation<R, S> {
         self.stack.try_push(value).map_err(|_| Error::StackFull)
     }
 
-    #[allow(clippy::cyclomatic_complexity)]
     fn evaluate_one_operation(&mut self) -> Result<OperationEvaluationResult<R>> {
         let operation = Operation::parse(&mut self.pc, self.encoding)?;
 
@@ -2889,7 +2885,6 @@ mod tests {
         result
     }
 
-    #[allow(clippy::too_many_arguments)]
     fn check_eval_with_args<F>(
         program: &[AssemblerEntry],
         expect: Result<&[Piece<EndianSlice<LittleEndian>>]>,

src/read/rnglists.rs

@@ -232,7 +232,7 @@ impl<R: Reader> RangeLists<R> {
         let (mut input, format) = if unit_encoding.version <= 4 {
             (self.debug_ranges.section.clone(), RangeListsFormat::Bare)
         } else {
-            (self.debug_rnglists.section.clone(), RangeListsFormat::RLE)
+            (self.debug_rnglists.section.clone(), RangeListsFormat::Rle)
         };
         input.skip(offset.0)?;
         Ok(RawRngListIter::new(input, unit_encoding, format))
@@ -277,7 +277,7 @@ enum RangeListsFormat {
     /// The bare range list format used before DWARF 5.
     Bare,
     /// The DW_RLE encoded range list format used in DWARF 5.
-    RLE,
+    Rle,
 }
 
 /// A raw iterator over an address range list.
@@ -355,10 +355,10 @@ impl<T: ReaderOffset> RawRngListEntry<T> {
         encoding: Encoding,
         format: RangeListsFormat,
     ) -> Result<Option<Self>> {
-        match format {
+        Ok(match format {
             RangeListsFormat::Bare => {
                 let range = RawRange::parse(input, encoding.address_size)?;
-                return Ok(if range.is_end() {
+                if range.is_end() {
                     None
                 } else if range.is_base_address(encoding.address_size) {
                     Some(RawRngListEntry::BaseAddress { addr: range.end })
@@ -367,9 +367,9 @@ impl<T: ReaderOffset> RawRngListEntry<T> {
                         begin: range.begin,
                         end: range.end,
                     })
-                });
+                }
             }
-            RangeListsFormat::RLE => Ok(match constants::DwRle(input.read_u8()?) {
+            RangeListsFormat::Rle => match constants::DwRle(input.read_u8()?) {
                 constants::DW_RLE_end_of_list => None,
                 constants::DW_RLE_base_addressx => Some(RawRngListEntry::BaseAddressx {
                     addr: DebugAddrIndex(input.read_uleb128().and_then(R::Offset::from_u64)?),
@@ -400,8 +400,8 @@ impl<T: ReaderOffset> RawRngListEntry<T> {
                 _ => {
                     return Err(Error::InvalidAddressRange);
                 }
-            }),
-        }
+            },
+        })
     }
 }