Rollup merge of rust-lang#142619 - klensy:or_fun_call, r=nnethercote

apply clippy::or_fun_call

Applies https://rust-lang.github.io/rust-clippy/master/index.html?groups=nursery#or_fun_call to reduce needless allocs.

Author: Kobzol

compiler/rustc_codegen_ssa/src/mir/debuginfo.rs

@@ -317,7 +317,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         let name = if bx.sess().fewer_names() {
             None
         } else {
-            Some(match whole_local_var.or(fallback_var.clone()) {
+            Some(match whole_local_var.or_else(|| fallback_var.clone()) {
                 Some(var) if var.name != sym::empty => var.name.to_string(),
                 _ => format!("{local:?}"),
             })

compiler/rustc_codegen_ssa/src/mir/naked_asm.rs

@@ -205,7 +205,7 @@ fn prefix_and_suffix<'tcx>(
     let mut end = String::new();
     match asm_binary_format {
         BinaryFormat::Elf => {
-            let section = link_section.unwrap_or(format!(".text.{asm_name}"));
+            let section = link_section.unwrap_or_else(|| format!(".text.{asm_name}"));
 
             let progbits = match is_arm {
                 true => "%progbits",
@@ -239,7 +239,7 @@ fn prefix_and_suffix<'tcx>(
             }
         }
         BinaryFormat::MachO => {
-            let section = link_section.unwrap_or("__TEXT,__text".to_string());
+            let section = link_section.unwrap_or_else(|| "__TEXT,__text".to_string());
             writeln!(begin, ".pushsection {},regular,pure_instructions", section).unwrap();
             writeln!(begin, ".balign {align_bytes}").unwrap();
             write_linkage(&mut begin).unwrap();
@@ -256,7 +256,7 @@ fn prefix_and_suffix<'tcx>(
             }
         }
         BinaryFormat::Coff => {
-            let section = link_section.unwrap_or(format!(".text.{asm_name}"));
+            let section = link_section.unwrap_or_else(|| format!(".text.{asm_name}"));
             writeln!(begin, ".pushsection {},\"xr\"", section).unwrap();
             writeln!(begin, ".balign {align_bytes}").unwrap();
             write_linkage(&mut begin).unwrap();
@@ -273,7 +273,7 @@ fn prefix_and_suffix<'tcx>(
             }
         }
         BinaryFormat::Wasm => {
-            let section = link_section.unwrap_or(format!(".text.{asm_name}"));
+            let section = link_section.unwrap_or_else(|| format!(".text.{asm_name}"));
 
             writeln!(begin, ".section {section},\"\",@").unwrap();
             // wasm functions cannot be aligned, so skip

compiler/rustc_hir_typeck/src/op.rs

@@ -706,7 +706,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         .sess
                         .source_map()
                         .span_to_snippet(lhs_expr.span)
-                        .unwrap_or("_".to_string()),
+                        .unwrap_or_else(|_| "_".to_string()),
                 };
 
                 if op.span().can_be_used_for_suggestions() {

compiler/rustc_metadata/src/locator.rs

@@ -1196,7 +1196,7 @@ impl CrateError {
                             .opts
                             .crate_name
                             .clone()
-                            .unwrap_or("<unknown>".to_string()),
+                            .unwrap_or_else(|| "<unknown>".to_string()),
                         is_nightly_build: sess.is_nightly_build(),
                         profiler_runtime: Symbol::intern(&sess.opts.unstable_opts.profiler_runtime),
                         locator_triple: locator.triple,
@@ -1217,7 +1217,11 @@ impl CrateError {
                     crate_name,
                     add_info: String::new(),
                     missing_core,
-                    current_crate: sess.opts.crate_name.clone().unwrap_or("<unknown>".to_string()),
+                    current_crate: sess
+                        .opts
+                        .crate_name
+                        .clone()
+                        .unwrap_or_else(|| "<unknown>".to_string()),
                     is_nightly_build: sess.is_nightly_build(),
                     profiler_runtime: Symbol::intern(&sess.opts.unstable_opts.profiler_runtime),
                     locator_triple: sess.opts.target_triple.clone(),

compiler/rustc_metadata/src/native_libs.rs

@@ -705,7 +705,7 @@ impl<'tcx> Collector<'tcx> {
             .map_or(import_name_type, |ord| Some(PeImportNameType::Ordinal(ord)));
 
         DllImport {
-            name: codegen_fn_attrs.link_name.unwrap_or(self.tcx.item_name(item)),
+            name: codegen_fn_attrs.link_name.unwrap_or_else(|| self.tcx.item_name(item)),
             import_name_type,
             calling_convention,
             span,

compiler/rustc_middle/src/query/mod.rs

@@ -1576,7 +1576,7 @@ rustc_queries! {
     query vtable_allocation(key: (Ty<'tcx>, Option<ty::ExistentialTraitRef<'tcx>>)) -> mir::interpret::AllocId {
         desc { |tcx| "vtable const allocation for <{} as {}>",
             key.0,
-            key.1.map(|trait_ref| format!("{trait_ref}")).unwrap_or("_".to_owned())
+            key.1.map(|trait_ref| format!("{trait_ref}")).unwrap_or_else(|| "_".to_owned())
         }
     }
 

compiler/rustc_passes/src/check_export.rs

@@ -53,11 +53,11 @@ impl<'tcx> ExportableItemCollector<'tcx> {
         let is_pub = visibilities.is_directly_public(def_id);
 
         if has_attr && !is_pub {
-            let vis = visibilities.effective_vis(def_id).cloned().unwrap_or(
+            let vis = visibilities.effective_vis(def_id).cloned().unwrap_or_else(|| {
                 EffectiveVisibility::from_vis(Visibility::Restricted(
                     self.tcx.parent_module_from_def_id(def_id).to_local_def_id(),
-                )),
-            );
+                ))
+            });
             let vis = vis.at_level(Level::Direct);
             let span = self.tcx.def_span(def_id);
 

compiler/rustc_session/src/filesearch.rs

@@ -209,10 +209,9 @@ pub fn get_or_default_sysroot() -> PathBuf {
         //
         // use `parent` twice to chop off the file name and then also the
         // directory containing the dll
-        let dir = dll.parent().and_then(|p| p.parent()).ok_or(format!(
-            "Could not move 2 levels upper using `parent()` on {}",
-            dll.display()
-        ))?;
+        let dir = dll.parent().and_then(|p| p.parent()).ok_or_else(|| {
+            format!("Could not move 2 levels upper using `parent()` on {}", dll.display())
+        })?;
 
         // if `dir` points to target's dir, move up to the sysroot
         let mut sysroot_dir = if dir.ends_with(crate::config::host_tuple()) {
@@ -265,5 +264,6 @@ pub fn get_or_default_sysroot() -> PathBuf {
         rustlib_path.exists().then_some(p)
     }
 
-    from_env_args_next().unwrap_or(default_from_rustc_driver_dll().expect("Failed finding sysroot"))
+    from_env_args_next()
+        .unwrap_or_else(|| default_from_rustc_driver_dll().expect("Failed finding sysroot"))
 }

compiler/rustc_trait_selection/src/error_reporting/infer/region.rs

@@ -891,7 +891,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
             (b'a'..=b'z')
                 .map(|c| format!("'{}", c as char))
                 .find(|candidate| !used_names.iter().any(|e| e.as_str() == candidate))
-                .unwrap_or("'lt".to_string())
+                .unwrap_or_else(|| "'lt".to_string())
         };
 
         let mut visitor = LifetimeReplaceVisitor {

compiler/rustc_trait_selection/src/traits/normalize.rs

@@ -224,7 +224,7 @@ impl<'a, 'b, 'tcx> AssocTypeNormalizer<'a, 'b, 'tcx> {
             )
             .ok()
             .flatten()
-            .unwrap_or(proj.to_term(infcx.tcx));
+            .unwrap_or_else(|| proj.to_term(infcx.tcx));
 
             PlaceholderReplacer::replace_placeholders(
                 infcx,