Merge pull request #469 from tempdragon/master

Clippy related fixes

18 files changed, 160 insertions, 158 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 839f3ba4de3..44730bab4ed 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -49,8 +49,8 @@ jobs:
       # `llvm-14-tools` is needed to install the `FileCheck` binary which is used for asm tests.
       run: sudo apt-get install ninja-build ripgrep llvm-14-tools
 
-    - name: Install rustfmt
-      run: rustup component add rustfmt
+    - name: Install rustfmt & clippy
+      run: rustup component add rustfmt clippy
 
     - name: Download artifact
       run: curl -LO https://github.com/antoyo/gcc/releases/latest/download/${{ matrix.libgccjit_version.gcc }}
@@ -98,6 +98,11 @@ jobs:
     - name: Check formatting
       run: cargo fmt -- --check
 
+    - name: clippy
+      run: |
+        cargo clippy --all-targets -- -D warnings
+        cargo clippy --all-targets --features master -- -D warnings
+
   duplicates:
     runs-on: ubuntu-latest
     steps:
diff --git a/src/attributes.rs b/src/attributes.rs
index 8602566ab8f..2ce0c83008f 100644
--- a/src/attributes.rs
+++ b/src/attributes.rs
@@ -92,7 +92,7 @@ pub fn from_fn_attrs<'gcc, 'tcx>(
     let mut function_features = function_features
         .iter()
         .flat_map(|feat| to_gcc_features(cx.tcx.sess, feat).into_iter())
-        .chain(codegen_fn_attrs.instruction_set.iter().map(|x| match x {
+        .chain(codegen_fn_attrs.instruction_set.iter().map(|x| match *x {
             InstructionSetAttr::ArmA32 => "-thumb-mode", // TODO(antoyo): support removing feature.
             InstructionSetAttr::ArmT32 => "thumb-mode",
         }))
@@ -118,8 +118,8 @@ pub fn from_fn_attrs<'gcc, 'tcx>(
 
             if feature.starts_with('-') {
                 Some(format!("no{}", feature))
-            } else if feature.starts_with('+') {
-                Some(feature[1..].to_string())
+            } else if let Some(stripped) = feature.strip_prefix('+') {
+                Some(stripped.to_string())
             } else {
                 Some(feature.to_string())
             }
diff --git a/src/back/lto.rs b/src/back/lto.rs
index 61e0f203ee0..96e0b84450f 100644
--- a/src/back/lto.rs
+++ b/src/back/lto.rs
@@ -128,8 +128,7 @@ fn prepare_lto(
             }
 
             let archive_data = unsafe {
-                Mmap::map(File::open(&path).expect("couldn't open rlib"))
-                    .expect("couldn't map rlib")
+                Mmap::map(File::open(path).expect("couldn't open rlib")).expect("couldn't map rlib")
             };
             let archive = ArchiveFile::parse(&*archive_data).expect("wanted an rlib");
             let obj_files = archive
diff --git a/src/back/write.rs b/src/back/write.rs
index 76a619a1af7..a38fc8c14fb 100644
--- a/src/back/write.rs
+++ b/src/back/write.rs
@@ -104,7 +104,7 @@ pub(crate) unsafe fn codegen(
                     // FIXME(antoyo): segfault in dump_reproducer_to_file() might be caused by
                     // transmuting an rvalue to an lvalue.
                     // Segfault is actually in gcc::jit::reproducer::get_identifier_as_lvalue
-                    context.dump_reproducer_to_file(&format!("/tmp/reproducers/{}.c", module.name));
+                    context.dump_reproducer_to_file(format!("/tmp/reproducers/{}.c", module.name));
                     println!("Dumped reproducer {}", module.name);
                 }
                 if env::var("CG_GCCJIT_DUMP_TO_FILE").as_deref() == Ok("1") {
diff --git a/src/base.rs b/src/base.rs
index 2a2d5741d13..79a29a1135a 100644
--- a/src/base.rs
+++ b/src/base.rs
@@ -135,7 +135,7 @@ pub fn compile_codegen_unit(
 
         let target_cpu = gcc_util::target_cpu(tcx.sess);
         if target_cpu != "generic" {
-            context.add_command_line_option(&format!("-march={}", target_cpu));
+            context.add_command_line_option(format!("-march={}", target_cpu));
         }
 
         if tcx
diff --git a/src/builder.rs b/src/builder.rs
index f5cda81f6ab..385ca7a44a7 100644
--- a/src/builder.rs
+++ b/src/builder.rs
@@ -225,7 +225,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 
         let mut on_stack_param_indices = FxHashSet::default();
         if let Some(indices) = self.on_stack_params.borrow().get(&gcc_func) {
-            on_stack_param_indices = indices.clone();
+            on_stack_param_indices.clone_from(indices);
         }
 
         if all_args_match {
@@ -256,8 +256,8 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
                         actual_val.dereference(self.location).to_rvalue()
                     } else {
                         assert!(
-                            !((actual_ty.is_vector() && !expected_ty.is_vector())
-                                || (!actual_ty.is_vector() && expected_ty.is_vector())),
+                            (!expected_ty.is_vector() || actual_ty.is_vector())
+                                && (expected_ty.is_vector() || !actual_ty.is_vector()),
                             "{:?} ({}) -> {:?} ({}), index: {:?}[{}]",
                             actual_ty,
                             actual_ty.is_vector(),
@@ -277,8 +277,8 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
             .collect();
 
         // NOTE: to take into account variadic functions.
-        for i in casted_args.len()..args.len() {
-            casted_args.push(args[i]);
+        for arg in args.iter().skip(casted_args.len()) {
+            casted_args.push(*arg);
         }
 
         Cow::Owned(casted_args)
@@ -353,7 +353,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
             let function_address_names = self.function_address_names.borrow();
             let original_function_name = function_address_names.get(&func_ptr);
             llvm::adjust_intrinsic_arguments(
-                &self,
+                self,
                 gcc_func,
                 args.into(),
                 &func_name,
@@ -361,7 +361,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
             )
         };
         let args_adjusted = args.len() != previous_arg_count;
-        let args = self.check_ptr_call("call", func_ptr, &*args);
+        let args = self.check_ptr_call("call", func_ptr, &args);
 
         // gccjit requires to use the result of functions, even when it's not used.
         // That's why we assign the result to a local or call add_eval().
@@ -373,7 +373,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
             unsafe { RETURN_VALUE_COUNT += 1 };
             let return_value = self.cx.context.new_call_through_ptr(self.location, func_ptr, &args);
             let return_value = llvm::adjust_intrinsic_return_value(
-                &self,
+                self,
                 return_value,
                 &func_name,
                 &args,
@@ -441,7 +441,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
         self.block.add_assignment(
             self.location,
             result,
-            self.cx.context.new_call(self.location, func, &args),
+            self.cx.context.new_call(self.location, func, args),
         );
         result.to_rvalue()
     }
@@ -595,7 +595,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
     ) -> RValue<'gcc> {
         let try_block = self.current_func().new_block("try");
 
-        let current_block = self.block.clone();
+        let current_block = self.block;
         self.block = try_block;
         let call = self.call(typ, fn_attrs, None, func, args, None); // TODO(antoyo): use funclet here?
         self.block = current_block;
@@ -1176,7 +1176,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
         // NOTE: due to opaque pointers now being used, we need to cast here.
         let ptr = self.context.new_cast(self.location, ptr, typ.make_pointer());
         // NOTE: array indexing is always considered in bounds in GCC (TODO(antoyo): to be verified).
-        let mut indices = indices.into_iter();
+        let mut indices = indices.iter();
         let index = indices.next().expect("first index in inbounds_gep");
         let mut result = self.context.new_array_access(self.location, ptr, *index);
         for index in indices {
@@ -1684,7 +1684,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
 
     fn zext(&mut self, value: RValue<'gcc>, dest_typ: Type<'gcc>) -> RValue<'gcc> {
         // FIXME(antoyo): this does not zero-extend.
-        if value.get_type().is_bool() && dest_typ.is_i8(&self.cx) {
+        if value.get_type().is_bool() && dest_typ.is_i8(self.cx) {
             // FIXME(antoyo): hack because base::from_immediate converts i1 to i8.
             // Fix the code in codegen_ssa::base::from_immediate.
             return value;
@@ -2057,7 +2057,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
                 self.context.new_rvalue_from_vector(self.location, mask_type, &vector_elements);
             let shifted = self.context.new_rvalue_vector_perm(self.location, res, res, mask);
             shift *= 2;
-            res = op(res, shifted, &self.context);
+            res = op(res, shifted, self.context);
         }
         self.context
             .new_vector_access(self.location, res, self.context.new_rvalue_zero(self.int_type))
@@ -2073,7 +2073,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
     }
 
     pub fn vector_reduce_op(&mut self, src: RValue<'gcc>, op: BinaryOp) -> RValue<'gcc> {
-        let loc = self.location.clone();
+        let loc = self.location;
         self.vector_reduce(src, |a, b, context| context.new_binary_op(loc, op, a.get_type(), a, b))
     }
 
@@ -2090,7 +2090,6 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
         let vector_type = src.get_type().unqualified().dyncast_vector().expect("vector type");
         let element_count = vector_type.get_num_units();
         (0..element_count)
-            .into_iter()
             .map(|i| {
                 self.context
                     .new_vector_access(
@@ -2121,7 +2120,6 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
         let vector_type = src.get_type().unqualified().dyncast_vector().expect("vector type");
         let element_count = vector_type.get_num_units();
         (0..element_count)
-            .into_iter()
             .map(|i| {
                 self.context
                     .new_vector_access(
@@ -2141,7 +2139,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 
     // Inspired by Hacker's Delight min implementation.
     pub fn vector_reduce_min(&mut self, src: RValue<'gcc>) -> RValue<'gcc> {
-        let loc = self.location.clone();
+        let loc = self.location;
         self.vector_reduce(src, |a, b, context| {
             let differences_or_zeros = difference_or_zero(loc, a, b, context);
             context.new_binary_op(loc, BinaryOp::Plus, b.get_type(), b, differences_or_zeros)
@@ -2150,7 +2148,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 
     // Inspired by Hacker's Delight max implementation.
     pub fn vector_reduce_max(&mut self, src: RValue<'gcc>) -> RValue<'gcc> {
-        let loc = self.location.clone();
+        let loc = self.location;
         self.vector_reduce(src, |a, b, context| {
             let differences_or_zeros = difference_or_zero(loc, a, b, context);
             context.new_binary_op(loc, BinaryOp::Minus, a.get_type(), a, differences_or_zeros)
@@ -2345,7 +2343,7 @@ impl<'tcx> HasParamEnv<'tcx> for Builder<'_, '_, 'tcx> {
 
 impl<'tcx> HasTargetSpec for Builder<'_, '_, 'tcx> {
     fn target_spec(&self) -> &Target {
-        &self.cx.target_spec()
+        self.cx.target_spec()
     }
 }
 
diff --git a/src/callee.rs b/src/callee.rs
index 84f49b6856d..9ad2e90122f 100644
--- a/src/callee.rs
+++ b/src/callee.rs
@@ -28,7 +28,7 @@ pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>)
 
     let fn_abi = cx.fn_abi_of_instance(instance, ty::List::empty());
 
-    let func = if let Some(_func) = cx.get_declared_value(&sym) {
+    let func = if let Some(_func) = cx.get_declared_value(sym) {
         // FIXME(antoyo): we never reach this because get_declared_value only returns global variables
         // and here we try to get a function.
         unreachable!();
@@ -68,7 +68,7 @@ pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>)
         }*/
     } else {
         cx.linkage.set(FunctionType::Extern);
-        let func = cx.declare_fn(&sym, &fn_abi);
+        let func = cx.declare_fn(sym, fn_abi);
 
         attributes::from_fn_attrs(cx, func, instance);
 
diff --git a/src/common.rs b/src/common.rs
index d243d7088ad..6a3b5442adf 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -21,7 +21,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
 
     fn global_string(&self, string: &str) -> LValue<'gcc> {
         // TODO(antoyo): handle non-null-terminated strings.
-        let string = self.context.new_string_literal(&*string);
+        let string = self.context.new_string_literal(string);
         let sym = self.generate_local_symbol_name("str");
         let global = self.declare_private_global(&sym, self.val_ty(string));
         global.global_set_initializer_rvalue(string);
@@ -170,7 +170,8 @@ impl<'gcc, 'tcx> ConstMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
                     return self
                         .context
                         .new_rvalue_from_double(ty, f32::from_bits(data as u32) as f64);
-                } else if ty == self.double_type {
+                }
+                if ty == self.double_type {
                     return self.context.new_rvalue_from_double(ty, f64::from_bits(data as u64));
                 }
 
@@ -293,7 +294,7 @@ impl<'gcc, 'tcx> SignType<'gcc, 'tcx> for Type<'gcc> {
         } else if self.is_ulonglong(cx) {
             cx.longlong_type
         } else {
-            self.clone()
+            *self
         }
     }
 
@@ -319,7 +320,7 @@ impl<'gcc, 'tcx> SignType<'gcc, 'tcx> for Type<'gcc> {
         } else if self.is_longlong(cx) {
             cx.ulonglong_type
         } else {
-            self.clone()
+            *self
         }
     }
 }
@@ -432,7 +433,7 @@ impl<'gcc, 'tcx> TypeReflection<'gcc, 'tcx> for Type<'gcc> {
     }
 
     fn is_vector(&self) -> bool {
-        let mut typ = self.clone();
+        let mut typ = *self;
         loop {
             if typ.dyncast_vector().is_some() {
                 return true;
diff --git a/src/consts.rs b/src/consts.rs
index 327c9bdada9..f47fd565533 100644
--- a/src/consts.rs
+++ b/src/consts.rs
@@ -66,7 +66,7 @@ impl<'gcc, 'tcx> StaticMethods for CodegenCx<'gcc, 'tcx> {
     fn codegen_static(&self, def_id: DefId, is_mutable: bool) {
         let attrs = self.tcx.codegen_fn_attrs(def_id);
 
-        let value = match codegen_static_initializer(&self, def_id) {
+        let value = match codegen_static_initializer(self, def_id) {
             Ok((value, _)) => value,
             // Error has already been reported
             Err(_) => return,
@@ -231,13 +231,8 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             }
 
             let is_tls = fn_attrs.flags.contains(CodegenFnAttrFlags::THREAD_LOCAL);
-            let global = self.declare_global(
-                &sym,
-                llty,
-                GlobalKind::Exported,
-                is_tls,
-                fn_attrs.link_section,
-            );
+            let global =
+                self.declare_global(sym, llty, GlobalKind::Exported, is_tls, fn_attrs.link_section);
 
             if !self.tcx.is_reachable_non_generic(def_id) {
                 #[cfg(feature = "master")]
@@ -246,7 +241,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
 
             global
         } else {
-            check_and_apply_linkage(&self, &fn_attrs, ty, sym)
+            check_and_apply_linkage(self, fn_attrs, ty, sym)
         };
 
         if !def_id.is_local() {
@@ -367,11 +362,8 @@ fn check_and_apply_linkage<'gcc, 'tcx>(
     let gcc_type = cx.layout_of(ty).gcc_type(cx);
     if let Some(linkage) = attrs.import_linkage {
         // Declare a symbol `foo` with the desired linkage.
-        let global1 = cx.declare_global_with_linkage(
-            &sym,
-            cx.type_i8(),
-            base::global_linkage_to_gcc(linkage),
-        );
+        let global1 =
+            cx.declare_global_with_linkage(sym, cx.type_i8(), base::global_linkage_to_gcc(linkage));
 
         // Declare an internal global `extern_with_linkage_foo` which
         // is initialized with the address of `foo`.  If `foo` is
@@ -380,7 +372,7 @@ fn check_and_apply_linkage<'gcc, 'tcx>(
         // `extern_with_linkage_foo` will instead be initialized to
         // zero.
         let mut real_name = "_rust_extern_with_linkage_".to_string();
-        real_name.push_str(&sym);
+        real_name.push_str(sym);
         let global2 = cx.define_global(&real_name, gcc_type, is_tls, attrs.link_section);
         // TODO(antoyo): set linkage.
         let value = cx.const_ptrcast(global1.get_address(None), gcc_type);
@@ -397,6 +389,6 @@ fn check_and_apply_linkage<'gcc, 'tcx>(
         // don't do this then linker errors can be generated where the linker
         // complains that one object files has a thread local version of the
         // symbol and another one doesn't.
-        cx.declare_global(&sym, gcc_type, GlobalKind::Imported, is_tls, attrs.link_section)
+        cx.declare_global(sym, gcc_type, GlobalKind::Imported, is_tls, attrs.link_section)
     }
 }
diff --git a/src/context.rs b/src/context.rs
index bc3d62f2679..1b9cfd3652c 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -384,7 +384,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
     }
 
     pub fn sess(&self) -> &'tcx Session {
-        &self.tcx.sess
+        self.tcx.sess
     }
 
     pub fn bitcast_if_needed(
@@ -431,7 +431,7 @@ impl<'gcc, 'tcx> MiscMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         let func_name = self.tcx.symbol_name(instance).name;
 
         let func = if self.intrinsics.borrow().contains_key(func_name) {
-            self.intrinsics.borrow()[func_name].clone()
+            self.intrinsics.borrow()[func_name]
         } else {
             get_fn(self, instance)
         };
@@ -485,7 +485,7 @@ impl<'gcc, 'tcx> MiscMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
                 let symbol_name = tcx.symbol_name(instance).name;
                 let fn_abi = self.fn_abi_of_instance(instance, ty::List::empty());
                 self.linkage.set(FunctionType::Extern);
-                let func = self.declare_fn(symbol_name, &fn_abi);
+                let func = self.declare_fn(symbol_name, fn_abi);
                 let func: RValue<'gcc> = unsafe { std::mem::transmute(func) };
                 func
             }
@@ -505,7 +505,7 @@ impl<'gcc, 'tcx> MiscMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
     }
 
     fn sess(&self) -> &Session {
-        &self.tcx.sess
+        self.tcx.sess
     }
 
     fn check_overflow(&self) -> bool {
@@ -612,7 +612,7 @@ impl<'b, 'tcx> CodegenCx<'b, 'tcx> {
         // user defined names
         let mut name = String::with_capacity(prefix.len() + 6);
         name.push_str(prefix);
-        name.push_str(".");
+        name.push('.');
         base_n::push_str(idx as u128, base_n::ALPHANUMERIC_ONLY, &mut name);
         name
     }
diff --git a/src/debuginfo.rs b/src/debuginfo.rs
index aed15769025..04c517e7d29 100644
--- a/src/debuginfo.rs
+++ b/src/debuginfo.rs
@@ -91,7 +91,7 @@ fn compute_mir_scopes<'gcc, 'tcx>(
 /// FIXME(tempdragon/?): Add Scope Support Here.
 fn make_mir_scope<'gcc, 'tcx>(
     cx: &CodegenCx<'gcc, 'tcx>,
-    instance: Instance<'tcx>,
+    _instance: Instance<'tcx>,
     mir: &Body<'tcx>,
     variables: &Option<BitSet<SourceScope>>,
     debug_context: &mut FunctionDebugContext<'tcx, (), Location<'gcc>>,
@@ -104,7 +104,7 @@ fn make_mir_scope<'gcc, 'tcx>(
 
     let scope_data = &mir.source_scopes[scope];
     let parent_scope = if let Some(parent) = scope_data.parent_scope {
-        make_mir_scope(cx, instance, mir, variables, debug_context, instantiated, parent);
+        make_mir_scope(cx, _instance, mir, variables, debug_context, instantiated, parent);
         debug_context.scopes[parent]
     } else {
         // The root is the function itself.
@@ -118,7 +118,7 @@ fn make_mir_scope<'gcc, 'tcx>(
         return;
     };
 
-    if let Some(vars) = variables {
+    if let Some(ref vars) = *variables {
         if !vars.contains(scope) && scope_data.inlined.is_none() {
             // Do not create a DIScope if there are no variables defined in this
             // MIR `SourceScope`, and it's not `inlined`, to avoid debuginfo bloat.
@@ -136,8 +136,14 @@ fn make_mir_scope<'gcc, 'tcx>(
     let inlined_at = scope_data.inlined.map(|(_, callsite_span)| {
         // FIXME(eddyb) this doesn't account for the macro-related
         // `Span` fixups that `rustc_codegen_ssa::mir::debuginfo` does.
-        let callsite_scope = parent_scope.adjust_dbg_scope_for_span(cx, callsite_span);
-        cx.dbg_loc(callsite_scope, parent_scope.inlined_at, callsite_span)
+
+        // TODO(tempdragon): Add scope support and then revert to cg_llvm version of this closure
+        // NOTE: These variables passed () here.
+        // Changed to comply to clippy.
+
+        /* let callsite_scope =  */
+        parent_scope.adjust_dbg_scope_for_span(cx, callsite_span);
+        cx.dbg_loc(/* callsite_scope */ (), parent_scope.inlined_at, callsite_span)
     });
     let p_inlined_at = parent_scope.inlined_at;
     // TODO(tempdragon): dbg_scope: Add support for scope extension here.
@@ -225,7 +231,7 @@ impl<'gcc, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
             file_end_pos: BytePos(0),
         };
         let mut fn_debug_context = FunctionDebugContext {
-            scopes: IndexVec::from_elem(empty_scope, &mir.source_scopes.as_slice()),
+            scopes: IndexVec::from_elem(empty_scope, mir.source_scopes.as_slice()),
             inlined_function_scopes: Default::default(),
         };
 
@@ -274,16 +280,19 @@ impl<'gcc, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
     ) -> Self::DILocation {
         let pos = span.lo();
         let DebugLoc { file, line, col } = self.lookup_debug_loc(pos);
-        let loc = match &file.name {
-            rustc_span::FileName::Real(name) => match name {
-                rustc_span::RealFileName::LocalPath(name) => {
+        let loc = match file.name {
+            rustc_span::FileName::Real(ref name) => match *name {
+                rustc_span::RealFileName::LocalPath(ref name) => {
                     if let Some(name) = name.to_str() {
                         self.context.new_location(name, line as i32, col as i32)
                     } else {
                         Location::null()
                     }
                 }
-                rustc_span::RealFileName::Remapped { local_path, virtual_name: _ } => {
+                rustc_span::RealFileName::Remapped {
+                    ref local_path,
+                    virtual_name: ref _unused,
+                } => {
                     if let Some(name) = local_path.as_ref() {
                         if let Some(name) = name.to_str() {
                             self.context.new_location(name, line as i32, col as i32)
diff --git a/src/declare.rs b/src/declare.rs
index db6edbab12d..a2b158ee0a7 100644
--- a/src/declare.rs
+++ b/src/declare.rs
@@ -35,7 +35,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
 
     pub fn declare_unnamed_global(&self, ty: Type<'gcc>) -> LValue<'gcc> {
         let name = self.generate_local_symbol_name("global");
-        self.context.new_global(None, GlobalKind::Internal, ty, &name)
+        self.context.new_global(None, GlobalKind::Internal, ty, name)
     }
 
     pub fn declare_global_with_linkage(
@@ -176,16 +176,14 @@ fn declare_raw_fn<'gcc>(
         cx.functions.borrow()[name]
     } else {
         let params: Vec<_> = param_types
-            .into_iter()
+            .iter()
             .enumerate()
-            .map(|(index, param)| {
-                cx.context.new_parameter(None, *param, &format!("param{}", index))
-            }) // TODO(antoyo): set name.
+            .map(|(index, param)| cx.context.new_parameter(None, *param, format!("param{}", index))) // TODO(antoyo): set name.
             .collect();
         #[cfg(not(feature = "master"))]
-        let name = mangle_name(name);
+        let name = &mangle_name(name);
         let func =
-            cx.context.new_function(None, cx.linkage.get(), return_type, &params, &name, variadic);
+            cx.context.new_function(None, cx.linkage.get(), return_type, &params, name, variadic);
         cx.functions.borrow_mut().insert(name.to_string(), func);
 
         #[cfg(feature = "master")]
@@ -200,10 +198,10 @@ fn declare_raw_fn<'gcc>(
             // create a wrapper function that calls rust_eh_personality.
 
             let params: Vec<_> = param_types
-                .into_iter()
+                .iter()
                 .enumerate()
                 .map(|(index, param)| {
-                    cx.context.new_parameter(None, *param, &format!("param{}", index))
+                    cx.context.new_parameter(None, *param, format!("param{}", index))
                 }) // TODO(antoyo): set name.
                 .collect();
             let gcc_func = cx.context.new_function(
diff --git a/src/int.rs b/src/int.rs
index 841bcf592e4..1b812b4d137 100644
--- a/src/int.rs
+++ b/src/int.rs
@@ -2,8 +2,6 @@
 //! This module exists because some integer types are not supported on some gcc platforms, e.g.
 //! 128-bit integers on 32-bit platforms and thus require to be handled manually.
 
-use std::convert::TryFrom;
-
 use gccjit::{BinaryOp, ComparisonOp, FunctionType, Location, RValue, ToRValue, Type, UnaryOp};
 use rustc_codegen_ssa::common::{IntPredicate, TypeKind};
 use rustc_codegen_ssa::traits::{BackendTypes, BaseTypeMethods, BuilderMethods, OverflowOp};
@@ -40,7 +38,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
             self.cx.context.new_unary_op(self.location, operation, typ, a)
         } else {
             let element_type = typ.dyncast_array().expect("element type");
-            self.from_low_high_rvalues(
+            self.concat_low_high_rvalues(
                 typ,
                 self.cx.context.new_unary_op(
                     self.location,
@@ -114,7 +112,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
             let shift_value = self.gcc_sub(b, sixty_four);
             let high = self.high(a);
             let sign = if a_type.is_signed(self) { high >> sixty_three } else { zero };
-            let array_value = self.from_low_high_rvalues(a_type, high >> shift_value, sign);
+            let array_value = self.concat_low_high_rvalues(a_type, high >> shift_value, sign);
             then_block.add_assignment(self.location, result, array_value);
             then_block.end_with_jump(self.location, after_block);
 
@@ -126,12 +124,15 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 
             let shift_value = self.gcc_sub(sixty_four, b);
             // NOTE: cast low to its unsigned type in order to perform a logical right shift.
-            let unsigned_type = native_int_type.to_unsigned(&self.cx);
+            let unsigned_type = native_int_type.to_unsigned(self.cx);
             let casted_low = self.context.new_cast(self.location, self.low(a), unsigned_type);
             let shifted_low = casted_low >> self.context.new_cast(self.location, b, unsigned_type);
             let shifted_low = self.context.new_cast(self.location, shifted_low, native_int_type);
-            let array_value =
-                self.from_low_high_rvalues(a_type, (high << shift_value) | shifted_low, high >> b);
+            let array_value = self.concat_low_high_rvalues(
+                a_type,
+                (high << shift_value) | shifted_low,
+                high >> b,
+            );
             actual_else_block.add_assignment(self.location, result, array_value);
             actual_else_block.end_with_jump(self.location, after_block);
 
@@ -255,10 +256,10 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
     ) -> (<Self as BackendTypes>::Value, <Self as BackendTypes>::Value) {
         use rustc_middle::ty::{Int, IntTy::*, Uint, UintTy::*};
 
-        let new_kind = match typ.kind() {
+        let new_kind = match *typ.kind() {
             Int(t @ Isize) => Int(t.normalize(self.tcx.sess.target.pointer_width)),
             Uint(t @ Usize) => Uint(t.normalize(self.tcx.sess.target.pointer_width)),
-            t @ (Uint(_) | Int(_)) => t.clone(),
+            t @ (Uint(_) | Int(_)) => t,
             _ => panic!("tried to get overflow intrinsic for op applied to non-int type"),
         };
 
@@ -344,7 +345,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
             }
         };
 
-        let intrinsic = self.context.get_builtin_function(&name);
+        let intrinsic = self.context.get_builtin_function(name);
         let res = self
             .current_func()
             // TODO(antoyo): is it correct to use rhs type instead of the parameter typ?
@@ -454,7 +455,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
             let native_int_type = a_type.dyncast_array().expect("get element type");
             // NOTE: cast low to its unsigned type in order to perform a comparison correctly (e.g.
             // the sign is only on high).
-            let unsigned_type = native_int_type.to_unsigned(&self.cx);
+            let unsigned_type = native_int_type.to_unsigned(self.cx);
 
             let lhs_low = self.context.new_cast(self.location, self.low(lhs), unsigned_type);
             let rhs_low = self.context.new_cast(self.location, self.low(rhs), unsigned_type);
@@ -589,7 +590,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
                 | IntPredicate::IntULT
                 | IntPredicate::IntULE => {
                     if !a_type.is_vector() {
-                        let unsigned_type = a_type.to_unsigned(&self.cx);
+                        let unsigned_type = a_type.to_unsigned(self.cx);
                         lhs = self.context.new_cast(self.location, lhs, unsigned_type);
                         rhs = self.context.new_cast(self.location, rhs, unsigned_type);
                     }
@@ -612,7 +613,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
         {
             a ^ b
         } else {
-            self.from_low_high_rvalues(
+            self.concat_low_high_rvalues(
                 a_type,
                 self.low(a) ^ self.low(b),
                 self.high(a) ^ self.high(b),
@@ -661,7 +662,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
             self.llbb().end_with_conditional(self.location, condition, then_block, else_block);
 
             let array_value =
-                self.from_low_high_rvalues(a_type, zero, self.low(a) << (b - sixty_four));
+                self.concat_low_high_rvalues(a_type, zero, self.low(a) << (b - sixty_four));
             then_block.add_assignment(self.location, result, array_value);
             then_block.end_with_jump(self.location, after_block);
 
@@ -673,13 +674,13 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 
             // NOTE: cast low to its unsigned type in order to perform a logical right shift.
             // TODO(antoyo): adjust this ^ comment.
-            let unsigned_type = native_int_type.to_unsigned(&self.cx);
+            let unsigned_type = native_int_type.to_unsigned(self.cx);
             let casted_low = self.context.new_cast(self.location, self.low(a), unsigned_type);
             let shift_value = self.context.new_cast(self.location, sixty_four - b, unsigned_type);
             let high_low =
                 self.context.new_cast(self.location, casted_low >> shift_value, native_int_type);
 
-            let array_value = self.from_low_high_rvalues(
+            let array_value = self.concat_low_high_rvalues(
                 a_type,
                 self.low(a) << b,
                 (self.high(a) << b) | high_low,
@@ -708,7 +709,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 
             // NOTE: we also need to swap the two elements here, in addition to swapping inside
             // the elements themselves like done above.
-            return self.from_low_high_rvalues(arg_type, swapped_msb, swapped_lsb);
+            return self.concat_low_high_rvalues(arg_type, swapped_msb, swapped_lsb);
         }
 
         // TODO(antoyo): check if it's faster to use string literals and a
@@ -727,10 +728,10 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
     pub fn gcc_int(&self, typ: Type<'gcc>, int: i64) -> RValue<'gcc> {
         if self.is_native_int_type_or_bool(typ) {
-            self.context.new_rvalue_from_long(typ, i64::try_from(int).expect("i64::try_from"))
+            self.context.new_rvalue_from_long(typ, int)
         } else {
             // NOTE: set the sign in high.
-            self.from_low_high(typ, int, -(int.is_negative() as i64))
+            self.concat_low_high(typ, int, -(int.is_negative() as i64))
         }
     }
 
@@ -740,10 +741,9 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             let num = self.context.new_rvalue_from_long(self.u64_type, int as i64);
             self.gcc_int_cast(num, typ)
         } else if self.is_native_int_type_or_bool(typ) {
-            self.context
-                .new_rvalue_from_long(typ, u64::try_from(int).expect("u64::try_from") as i64)
+            self.context.new_rvalue_from_long(typ, int as i64)
         } else {
-            self.from_low_high(typ, int as i64, 0)
+            self.concat_low_high(typ, int as i64, 0)
         }
     }
 
@@ -760,7 +760,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
                 let shift = high << sixty_four;
                 shift | self.context.new_cast(None, low, typ)
             } else {
-                self.from_low_high(typ, low as i64, high as i64)
+                self.concat_low_high(typ, low as i64, high as i64)
             }
         } else if typ.is_i128(self) {
             // FIXME(antoyo): libgccjit cannot create 128-bit values yet.
@@ -775,7 +775,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         if self.is_native_int_type_or_bool(typ) {
             self.context.new_rvalue_zero(typ)
         } else {
-            self.from_low_high(typ, 0, 0)
+            self.concat_low_high(typ, 0, 0)
         }
     }
 
@@ -813,7 +813,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
                 "both types should either be native or non-native for or operation"
             );
             let native_int_type = a_type.dyncast_array().expect("get element type");
-            self.from_low_high_rvalues(
+            self.concat_low_high_rvalues(
                 a_type,
                 self.context.new_binary_op(
                     loc,
@@ -858,7 +858,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             let is_negative =
                 self.context.new_comparison(None, ComparisonOp::LessThan, value, zero);
             let is_negative = self.gcc_int_cast(is_negative, dest_element_type);
-            self.from_low_high_rvalues(
+            self.concat_low_high_rvalues(
                 dest_typ,
                 self.context.new_cast(None, value, dest_element_type),
                 self.context.new_unary_op(None, UnaryOp::Minus, dest_element_type, is_negative),
@@ -978,7 +978,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             .to_rvalue()
     }
 
-    fn from_low_high_rvalues(
+    fn concat_low_high_rvalues(
         &self,
         typ: Type<'gcc>,
         low: RValue<'gcc>,
@@ -993,7 +993,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         self.context.new_array_constructor(None, typ, &values)
     }
 
-    fn from_low_high(&self, typ: Type<'gcc>, low: i64, high: i64) -> RValue<'gcc> {
+    fn concat_low_high(&self, typ: Type<'gcc>, low: i64, high: i64) -> RValue<'gcc> {
         let (first, last) = match self.sess().target.options.endian {
             Endian::Little => (low, high),
             Endian::Big => (high, low),
diff --git a/src/intrinsic/llvm.rs b/src/intrinsic/llvm.rs
index ce8dee69a98..c845ee5fe5f 100644
--- a/src/intrinsic/llvm.rs
+++ b/src/intrinsic/llvm.rs
@@ -15,7 +15,7 @@ pub fn adjust_intrinsic_arguments<'a, 'b, 'gcc, 'tcx>(
     // Some LLVM intrinsics do not map 1-to-1 to GCC intrinsics, so we add the missing
     // arguments here.
     if gcc_func.get_param_count() != args.len() {
-        match &*func_name {
+        match func_name {
             // NOTE: the following intrinsics have a different number of parameters in LLVM and GCC.
             "__builtin_ia32_prold512_mask"
             | "__builtin_ia32_pmuldq512_mask"
@@ -380,7 +380,7 @@ pub fn adjust_intrinsic_arguments<'a, 'b, 'gcc, 'tcx>(
             _ => (),
         }
     } else {
-        match &*func_name {
+        match func_name {
             "__builtin_ia32_rndscaless_mask_round" | "__builtin_ia32_rndscalesd_mask_round" => {
                 let new_args = args.to_vec();
                 let arg3_type = gcc_func.get_param_type(2);
@@ -629,14 +629,11 @@ pub fn intrinsic<'gcc, 'tcx>(name: &str, cx: &CodegenCx<'gcc, 'tcx>) -> Function
 
 #[cfg(feature = "master")]
 pub fn intrinsic<'gcc, 'tcx>(name: &str, cx: &CodegenCx<'gcc, 'tcx>) -> Function<'gcc> {
-    match name {
-        "llvm.prefetch" => {
-            let gcc_name = "__builtin_prefetch";
-            let func = cx.context.get_builtin_function(gcc_name);
-            cx.functions.borrow_mut().insert(gcc_name.to_string(), func);
-            return func;
-        }
-        _ => (),
+    if name == "llvm.prefetch" {
+        let gcc_name = "__builtin_prefetch";
+        let func = cx.context.get_builtin_function(gcc_name);
+        cx.functions.borrow_mut().insert(gcc_name.to_string(), func);
+        return func;
     }
 
     let gcc_name = match name {
diff --git a/src/intrinsic/mod.rs b/src/intrinsic/mod.rs
index a6c8b72e851..eca4a72c756 100644
--- a/src/intrinsic/mod.rs
+++ b/src/intrinsic/mod.rs
@@ -91,7 +91,7 @@ fn get_simple_intrinsic<'gcc, 'tcx>(
         sym::abort => "abort",
         _ => return None,
     };
-    Some(cx.context.get_builtin_function(&gcc_name))
+    Some(cx.context.get_builtin_function(gcc_name))
 }
 
 impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
@@ -122,6 +122,11 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
         let result = PlaceRef::new_sized(llresult, fn_abi.ret.layout);
 
         let simple = get_simple_intrinsic(self, name);
+
+        // FIXME(tempdragon): Re-enable `clippy::suspicious_else_formatting` if the following issue is solved:
+        // https://github.com/rust-lang/rust-clippy/issues/12497
+        // and leave `else if use_integer_compare` to be placed "as is".
+        #[allow(clippy::suspicious_else_formatting)]
         let llval = match name {
             _ if simple.is_some() => {
                 // FIXME(antoyo): remove this cast when the API supports function.
@@ -166,7 +171,7 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
             sym::volatile_load | sym::unaligned_volatile_load => {
                 let tp_ty = fn_args.type_at(0);
                 let ptr = args[0].immediate();
-                let load = if let PassMode::Cast { cast: ty, pad_i32: _ } = &fn_abi.ret.mode {
+                let load = if let PassMode::Cast { cast: ref ty, pad_i32: _ } = fn_abi.ret.mode {
                     let gcc_ty = ty.gcc_type(self);
                     self.volatile_load(gcc_ty, ptr)
                 } else {
@@ -385,7 +390,7 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
         };
 
         if !fn_abi.ret.is_ignore() {
-            if let PassMode::Cast { cast: ty, .. } = &fn_abi.ret.mode {
+            if let PassMode::Cast { cast: ref ty, .. } = fn_abi.ret.mode {
                 let ptr_llty = self.type_ptr_to(ty.gcc_type(self));
                 let ptr = self.pointercast(result.llval, ptr_llty);
                 self.store(llval, ptr, result.align);
@@ -586,7 +591,7 @@ fn int_type_width_signed<'gcc, 'tcx>(
     ty: Ty<'tcx>,
     cx: &CodegenCx<'gcc, 'tcx>,
 ) -> Option<(u64, bool)> {
-    match ty.kind() {
+    match *ty.kind() {
         ty::Int(t) => Some((
             match t {
                 rustc_middle::ty::IntTy::Isize => u64::from(cx.tcx.sess.target.pointer_width),
@@ -699,13 +704,13 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
         let count_leading_zeroes =
             // TODO(antoyo): write a new function Type::is_compatible_with(&Type) and use it here
             // instead of using is_uint().
-            if arg_type.is_uint(&self.cx) {
+            if arg_type.is_uint(self.cx) {
                 "__builtin_clz"
             }
-            else if arg_type.is_ulong(&self.cx) {
+            else if arg_type.is_ulong(self.cx) {
                 "__builtin_clzl"
             }
-            else if arg_type.is_ulonglong(&self.cx) {
+            else if arg_type.is_ulonglong(self.cx) {
                 "__builtin_clzll"
             }
             else if width == 128 {
@@ -780,17 +785,17 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
         let (count_trailing_zeroes, expected_type) =
             // TODO(antoyo): write a new function Type::is_compatible_with(&Type) and use it here
             // instead of using is_uint().
-            if arg_type.is_uchar(&self.cx) || arg_type.is_ushort(&self.cx) || arg_type.is_uint(&self.cx) {
+            if arg_type.is_uchar(self.cx) || arg_type.is_ushort(self.cx) || arg_type.is_uint(self.cx) {
                 // NOTE: we don't need to & 0xFF for uchar because the result is undefined on zero.
                 ("__builtin_ctz", self.cx.uint_type)
             }
-            else if arg_type.is_ulong(&self.cx) {
+            else if arg_type.is_ulong(self.cx) {
                 ("__builtin_ctzl", self.cx.ulong_type)
             }
-            else if arg_type.is_ulonglong(&self.cx) {
+            else if arg_type.is_ulonglong(self.cx) {
                 ("__builtin_ctzll", self.cx.ulonglong_type)
             }
-            else if arg_type.is_u128(&self.cx) {
+            else if arg_type.is_u128(self.cx) {
                 // Adapted from the algorithm to count leading zeroes from: https://stackoverflow.com/a/28433850/389119
                 let array_type = self.context.new_array_type(None, arg_type, 3);
                 let result = self.current_func()
@@ -872,7 +877,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 
         // only break apart 128-bit ints if they're not natively supported
         // TODO(antoyo): remove this if/when native 128-bit integers land in libgccjit
-        if value_type.is_u128(&self.cx) && !self.cx.supports_128bit_integers {
+        if value_type.is_u128(self.cx) && !self.cx.supports_128bit_integers {
             let sixty_four = self.gcc_int(value_type, 64);
             let right_shift = self.gcc_lshr(value, sixty_four);
             let high = self.gcc_int_cast(right_shift, self.cx.ulonglong_type);
@@ -995,7 +1000,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 
             // Return `result_type`'s maximum or minimum value on overflow
             // NOTE: convert the type to unsigned to have an unsigned shift.
-            let unsigned_type = result_type.to_unsigned(&self.cx);
+            let unsigned_type = result_type.to_unsigned(self.cx);
             let shifted = self.gcc_lshr(
                 self.gcc_int_cast(lhs, unsigned_type),
                 self.gcc_int(unsigned_type, width as i64 - 1),
diff --git a/src/intrinsic/simd.rs b/src/intrinsic/simd.rs
index e9af34059a0..6d8ed519b4c 100644
--- a/src/intrinsic/simd.rs
+++ b/src/intrinsic/simd.rs
@@ -71,11 +71,11 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
         let expected_bytes = len / 8 + ((len % 8 > 0) as u64);
 
         let mask_ty = arg_tys[0];
-        let mut mask = match mask_ty.kind() {
+        let mut mask = match *mask_ty.kind() {
             ty::Int(i) if i.bit_width() == Some(expected_int_bits) => args[0].immediate(),
             ty::Uint(i) if i.bit_width() == Some(expected_int_bits) => args[0].immediate(),
             ty::Array(elem, len)
-                if matches!(elem.kind(), ty::Uint(ty::UintTy::U8))
+                if matches!(*elem.kind(), ty::Uint(ty::UintTy::U8))
                     && len.try_eval_target_usize(bx.tcx, ty::ParamEnv::reveal_all())
                         == Some(expected_bytes) =>
             {
@@ -308,10 +308,9 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
                 })
                 .collect();
             return Ok(bx.context.new_rvalue_from_vector(None, v_type, &elems));
-        } else {
-            // avoid the unnecessary truncation as an optimization.
-            return Ok(bx.context.new_bitcast(None, result, v_type));
         }
+        // avoid the unnecessary truncation as an optimization.
+        return Ok(bx.context.new_bitcast(None, result, v_type));
     }
     // since gcc doesn't have vector shuffle methods available in non-patched builds, fallback to
     // component-wise bitreverses if they're not available.
@@ -354,8 +353,8 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
     if name == sym::simd_shuffle {
         // Make sure this is actually an array, since typeck only checks the length-suffixed
         // version of this intrinsic.
-        let n: u64 = match args[2].layout.ty.kind() {
-            ty::Array(ty, len) if matches!(ty.kind(), ty::Uint(ty::UintTy::U32)) => {
+        let n: u64 = match *args[2].layout.ty.kind() {
+            ty::Array(ty, len) if matches!(*ty.kind(), ty::Uint(ty::UintTy::U32)) => {
                 len.try_eval_target_usize(bx.cx.tcx, ty::ParamEnv::reveal_all()).unwrap_or_else(
                     || span_bug!(span, "could not evaluate shuffle index array length"),
                 )
@@ -428,7 +427,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
             m_len == v_len,
             InvalidMonomorphization::MismatchedLengths { span, name, m_len, v_len }
         );
-        match m_elem_ty.kind() {
+        match *m_elem_ty.kind() {
             ty::Int(_) => {}
             _ => return_error!(InvalidMonomorphization::MaskType { span, name, ty: m_elem_ty }),
         }
@@ -461,13 +460,13 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
             Unsupported,
         }
 
-        let in_style = match in_elem.kind() {
+        let in_style = match *in_elem.kind() {
             ty::Int(_) | ty::Uint(_) => Style::Int,
             ty::Float(_) => Style::Float,
             _ => Style::Unsupported,
         };
 
-        let out_style = match out_elem.kind() {
+        let out_style = match *out_elem.kind() {
             ty::Int(_) | ty::Uint(_) => Style::Int,
             ty::Float(_) => Style::Float,
             _ => Style::Unsupported,
@@ -494,7 +493,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
     macro_rules! arith_binary {
         ($($name: ident: $($($p: ident),* => $call: ident),*;)*) => {
             $(if name == sym::$name {
-                match in_elem.kind() {
+                match *in_elem.kind() {
                     $($(ty::$p(_))|* => {
                         return Ok(bx.$call(args[0].immediate(), args[1].immediate()))
                     })*
@@ -532,7 +531,6 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
         let sign_shift = bx.context.new_rvalue_from_int(elem_type, elem_size as i32 - 1);
         let one = bx.context.new_rvalue_one(elem_type);
 
-        let mut shift = 0;
         for i in 0..in_len {
             let elem =
                 bx.extract_element(vector, bx.context.new_rvalue_from_int(bx.int_type, i as i32));
@@ -540,17 +538,16 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
             let masked = shifted & one;
             result = result
                 | (bx.context.new_cast(None, masked, result_type)
-                    << bx.context.new_rvalue_from_int(result_type, shift));
-            shift += 1;
+                    << bx.context.new_rvalue_from_int(result_type, i as i32));
         }
 
-        match ret_ty.kind() {
+        match *ret_ty.kind() {
             ty::Uint(i) if i.bit_width() == Some(expected_int_bits) => {
                 // Zero-extend iN to the bitmask type:
                 return Ok(result);
             }
             ty::Array(elem, len)
-                if matches!(elem.kind(), ty::Uint(ty::UintTy::U8))
+                if matches!(*elem.kind(), ty::Uint(ty::UintTy::U8))
                     && len.try_eval_target_usize(bx.tcx, ty::ParamEnv::reveal_all())
                         == Some(expected_bytes) =>
             {
@@ -589,7 +586,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
                 return Err(());
             }};
         }
-        let (elem_ty_str, elem_ty) = if let ty::Float(f) = in_elem.kind() {
+        let (elem_ty_str, elem_ty) = if let ty::Float(ref f) = *in_elem.kind() {
             let elem_ty = bx.cx.type_float_from_ty(*f);
             match f.bit_width() {
                 32 => ("f", elem_ty),
@@ -796,7 +793,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
 
         // This counts how many pointers
         fn ptr_count(t: Ty<'_>) -> usize {
-            match t.kind() {
+            match *t.kind() {
                 ty::RawPtr(p) => 1 + ptr_count(p.ty),
                 _ => 0,
             }
@@ -804,7 +801,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
 
         // Non-ptr type
         fn non_ptr(t: Ty<'_>) -> Ty<'_> {
-            match t.kind() {
+            match *t.kind() {
                 ty::RawPtr(p) => non_ptr(p.ty),
                 _ => t,
             }
@@ -814,7 +811,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
         // to the element type of the first argument
         let (_, element_ty0) = arg_tys[0].simd_size_and_type(bx.tcx());
         let (_, element_ty1) = arg_tys[1].simd_size_and_type(bx.tcx());
-        let (pointer_count, underlying_ty) = match element_ty1.kind() {
+        let (pointer_count, underlying_ty) = match *element_ty1.kind() {
             ty::RawPtr(p) if p.ty == in_elem => (ptr_count(element_ty1), non_ptr(element_ty1)),
             _ => {
                 require!(
@@ -838,7 +835,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
 
         // The element type of the third argument must be a signed integer type of any width:
         let (_, element_ty2) = arg_tys[2].simd_size_and_type(bx.tcx());
-        match element_ty2.kind() {
+        match *element_ty2.kind() {
             ty::Int(_) => (),
             _ => {
                 require!(
@@ -910,7 +907,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
 
         // This counts how many pointers
         fn ptr_count(t: Ty<'_>) -> usize {
-            match t.kind() {
+            match *t.kind() {
                 ty::RawPtr(p) => 1 + ptr_count(p.ty),
                 _ => 0,
             }
@@ -918,7 +915,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
 
         // Non-ptr type
         fn non_ptr(t: Ty<'_>) -> Ty<'_> {
-            match t.kind() {
+            match *t.kind() {
                 ty::RawPtr(p) => non_ptr(p.ty),
                 _ => t,
             }
@@ -929,7 +926,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
         let (_, element_ty0) = arg_tys[0].simd_size_and_type(bx.tcx());
         let (_, element_ty1) = arg_tys[1].simd_size_and_type(bx.tcx());
         let (_, element_ty2) = arg_tys[2].simd_size_and_type(bx.tcx());
-        let (pointer_count, underlying_ty) = match element_ty1.kind() {
+        let (pointer_count, underlying_ty) = match *element_ty1.kind() {
             ty::RawPtr(p) if p.ty == in_elem && p.mutbl == hir::Mutability::Mut => {
                 (ptr_count(element_ty1), non_ptr(element_ty1))
             }
@@ -954,7 +951,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
         assert_eq!(underlying_ty, non_ptr(element_ty0));
 
         // The element type of the third argument must be a signed integer type of any width:
-        match element_ty2.kind() {
+        match *element_ty2.kind() {
             ty::Int(_) => (),
             _ => {
                 require!(
@@ -1012,7 +1009,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
     macro_rules! arith_unary {
         ($($name: ident: $($($p: ident),* => $call: ident),*;)*) => {
             $(if name == sym::$name {
-                match in_elem.kind() {
+                match *in_elem.kind() {
                     $($(ty::$p(_))|* => {
                         return Ok(bx.$call(args[0].immediate()))
                     })*
@@ -1136,7 +1133,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
                     ret_ty == in_elem,
                     InvalidMonomorphization::ReturnType { span, name, in_elem, in_ty, ret_ty }
                 );
-                return match in_elem.kind() {
+                return match *in_elem.kind() {
                     ty::Int(_) | ty::Uint(_) => {
                         let r = bx.vector_reduce_op(args[0].immediate(), $vec_op);
                         if $ordered {
@@ -1205,7 +1202,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
                     ret_ty == in_elem,
                     InvalidMonomorphization::ReturnType { span, name, in_elem, in_ty, ret_ty }
                 );
-                return match in_elem.kind() {
+                return match *in_elem.kind() {
                     ty::Int(_) | ty::Uint(_) => Ok(bx.$int_red(args[0].immediate())),
                     ty::Float(_) => Ok(bx.$float_red(args[0].immediate())),
                     _ => return_error!(InvalidMonomorphization::UnsupportedSymbol {
@@ -1234,7 +1231,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
                     );
                     args[0].immediate()
                 } else {
-                    match in_elem.kind() {
+                    match *in_elem.kind() {
                         ty::Int(_) | ty::Uint(_) => {}
                         _ => return_error!(InvalidMonomorphization::UnsupportedSymbol {
                             span,
@@ -1248,7 +1245,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
 
                     args[0].immediate()
                 };
-                return match in_elem.kind() {
+                return match *in_elem.kind() {
                     ty::Int(_) | ty::Uint(_) => {
                         let r = bx.vector_reduce_op(input, $op);
                         Ok(if !$boolean {
diff --git a/src/lib.rs b/src/lib.rs
index a4ee3015b8d..616b1944798 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -29,6 +29,7 @@
 #![warn(rust_2018_idioms)]
 #![warn(unused_lifetimes)]
 #![deny(clippy::pattern_type_mismatch)]
+#![allow(clippy::needless_lifetimes)]
 
 extern crate rustc_apfloat;
 extern crate rustc_ast;
diff --git a/src/type_of.rs b/src/type_of.rs
index 8f9bfbbd18f..1c9a41649aa 100644
--- a/src/type_of.rs
+++ b/src/type_of.rs
@@ -90,7 +90,7 @@ fn uncached_gcc_type<'gcc, 'tcx>(
         Abi::Uninhabited | Abi::Aggregate { .. } => {}
     }
 
-    let name = match layout.ty.kind() {
+    let name = match *layout.ty.kind() {
         // FIXME(eddyb) producing readable type names for trait objects can result
         // in problematically distinct types due to HRTB and subtyping (see #47638).
         // ty::Dynamic(..) |
@@ -220,7 +220,7 @@ impl<'tcx> LayoutGccExt<'tcx> for TyAndLayout<'tcx> {
                 // to fn_ptr_backend_type handle the on-stack attribute.
                 // TODO(antoyo): find a less hackish way to hande the on-stack attribute.
                 ty::FnPtr(sig) => {
-                    cx.fn_ptr_backend_type(&cx.fn_abi_of_fn_ptr(sig, ty::List::empty()))
+                    cx.fn_ptr_backend_type(cx.fn_abi_of_fn_ptr(sig, ty::List::empty()))
                 }
                 _ => self.scalar_gcc_type_at(cx, scalar, Size::ZERO),
             };