Auto merge of #13227 - Veykril:core-pref, r=Veykril

Restructure `find_path` into a separate functions for modules and non-module items

Follow up to #13212
Also renames `prefer_core` imports config to `prefer_no_std` and changes the behavior of no_std path searching by preferring `core` paths `over` alloc

This PR turned into a slight rewrite, so it unfortunately does a few more things that I initially planned to (including a bug fix for enum variant paths)

Author: bors

crates/hir-def/src/find_path.rs

@@ -457,8 +457,15 @@ impl ItemInNs {
     /// Returns the crate defining this item (or `None` if `self` is built-in).
     pub fn krate(&self, db: &dyn DefDatabase) -> Option<CrateId> {
         match self {
-            ItemInNs::Types(did) | ItemInNs::Values(did) => did.module(db).map(|m| m.krate),
+            ItemInNs::Types(id) | ItemInNs::Values(id) => id.module(db).map(|m| m.krate),
             ItemInNs::Macros(id) => Some(id.module(db).krate),
         }
     }
+
+    pub fn module(&self, db: &dyn DefDatabase) -> Option<ModuleId> {
+        match self {
+            ItemInNs::Types(id) | ItemInNs::Values(id) => id.module(db),
+            ItemInNs::Macros(id) => Some(id.module(db)),
+        }
+    }
 }

crates/hir-def/src/item_scope.rs

@@ -585,9 +585,9 @@ impl Module {
         self,
         db: &dyn DefDatabase,
         item: impl Into<ItemInNs>,
-        prefer_core: bool,
+        prefer_no_std: bool,
     ) -> Option<ModPath> {
-        hir_def::find_path::find_path(db, item.into().into(), self.into(), prefer_core)
+        hir_def::find_path::find_path(db, item.into().into(), self.into(), prefer_no_std)
     }
 
     /// Finds a path that can be used to refer to the given item from within
@@ -597,14 +597,14 @@ impl Module {
         db: &dyn DefDatabase,
         item: impl Into<ItemInNs>,
         prefix_kind: PrefixKind,
-        prefer_core: bool,
+        prefer_no_std: bool,
     ) -> Option<ModPath> {
         hir_def::find_path::find_path_prefixed(
             db,
             item.into().into(),
             self.into(),
             prefix_kind,
-            prefer_core,
+            prefer_no_std,
         )
     }
 }

crates/hir/src/lib.rs

@@ -13,5 +13,5 @@ pub struct AssistConfig {
     pub snippet_cap: Option<SnippetCap>,
     pub allowed: Option<Vec<AssistKind>>,
     pub insert_use: InsertUseConfig,
-    pub prefer_core: bool,
+    pub prefer_no_std: bool,
 }

crates/ide-assists/src/assist_config.rs

@@ -87,7 +87,7 @@ pub(crate) fn add_missing_match_arms(acc: &mut Assists, ctx: &AssistContext<'_>)
             .into_iter()
             .filter_map(|variant| {
                 Some((
-                    build_pat(ctx.db(), module, variant, ctx.config.prefer_core)?,
+                    build_pat(ctx.db(), module, variant, ctx.config.prefer_no_std)?,
                     variant.should_be_hidden(ctx.db(), module.krate()),
                 ))
             })
@@ -133,7 +133,7 @@ pub(crate) fn add_missing_match_arms(acc: &mut Assists, ctx: &AssistContext<'_>)
                     .iter()
                     .any(|variant| variant.should_be_hidden(ctx.db(), module.krate()));
                 let patterns = variants.into_iter().filter_map(|variant| {
-                    build_pat(ctx.db(), module, variant, ctx.config.prefer_core)
+                    build_pat(ctx.db(), module, variant, ctx.config.prefer_no_std)
                 });
 
                 (ast::Pat::from(make::tuple_pat(patterns)), is_hidden)
@@ -354,12 +354,12 @@ fn build_pat(
     db: &RootDatabase,
     module: hir::Module,
     var: ExtendedVariant,
-    prefer_core: bool,
+    prefer_no_std: bool,
 ) -> Option<ast::Pat> {
     match var {
         ExtendedVariant::Variant(var) => {
             let path =
-                mod_path_to_ast(&module.find_use_path(db, ModuleDef::from(var), prefer_core)?);
+                mod_path_to_ast(&module.find_use_path(db, ModuleDef::from(var), prefer_no_std)?);
 
             // FIXME: use HIR for this; it doesn't currently expose struct vs. tuple vs. unit variants though
             let pat: ast::Pat = match var.source(db)?.value.kind() {

crates/ide-assists/src/handlers/add_missing_match_arms.rs

@@ -92,7 +92,7 @@ pub(crate) fn auto_import(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<
     let mut proposed_imports = import_assets.search_for_imports(
         &ctx.sema,
         ctx.config.insert_use.prefix_kind,
-        ctx.config.prefer_core,
+        ctx.config.prefer_no_std,
     );
     if proposed_imports.is_empty() {
         return None;

crates/ide-assists/src/handlers/auto_import.rs

@@ -50,7 +50,7 @@ pub(crate) fn convert_into_to_from(acc: &mut Assists, ctx: &AssistContext<'_>) -
             _ => return None,
         };
 
-        mod_path_to_ast(&module.find_use_path(ctx.db(), src_type_def, ctx.config.prefer_core)?)
+        mod_path_to_ast(&module.find_use_path(ctx.db(), src_type_def, ctx.config.prefer_no_std)?)
     };
 
     let dest_type = match &ast_trait {

crates/ide-assists/src/handlers/convert_into_to_from.rs

@@ -152,7 +152,7 @@ pub(crate) fn extract_function(acc: &mut Assists, ctx: &AssistContext<'_>) -> Op
                         ctx.sema.db,
                         ModuleDef::from(control_flow_enum),
                         ctx.config.insert_use.prefix_kind,
-                        ctx.config.prefer_core,
+                        ctx.config.prefer_no_std,
                     );
 
                     if let Some(mod_path) = mod_path {

crates/ide-assists/src/handlers/extract_function.rs

@@ -409,7 +409,7 @@ fn process_references(
                     ctx.sema.db,
                     *enum_module_def,
                     ctx.config.insert_use.prefix_kind,
-                    ctx.config.prefer_core,
+                    ctx.config.prefer_no_std,
                 );
                 if let Some(mut mod_path) = mod_path {
                     mod_path.pop_segment();

crates/ide-assists/src/handlers/extract_struct_from_enum_variant.rs

@@ -59,7 +59,7 @@ fn generate_record_deref(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<(
     let module = ctx.sema.to_def(&strukt)?.module(ctx.db());
     let trait_ = deref_type_to_generate.to_trait(&ctx.sema, module.krate())?;
     let trait_path =
-        module.find_use_path(ctx.db(), ModuleDef::Trait(trait_), ctx.config.prefer_core)?;
+        module.find_use_path(ctx.db(), ModuleDef::Trait(trait_), ctx.config.prefer_no_std)?;
 
     let field_type = field.ty()?;
     let field_name = field.name()?;
@@ -100,7 +100,7 @@ fn generate_tuple_deref(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()
     let module = ctx.sema.to_def(&strukt)?.module(ctx.db());
     let trait_ = deref_type_to_generate.to_trait(&ctx.sema, module.krate())?;
     let trait_path =
-        module.find_use_path(ctx.db(), ModuleDef::Trait(trait_), ctx.config.prefer_core)?;
+        module.find_use_path(ctx.db(), ModuleDef::Trait(trait_), ctx.config.prefer_no_std)?;
 
     let field_type = field.ty()?;
     let target = field.syntax().text_range();