internal: Improve macro token mapping heuristics

crates/hir-expand/src/lib.rs

@@ -279,6 +279,7 @@ pub enum MacroCallKind {
 }
 
 pub trait HirFileIdExt {
+    fn edition(self, db: &dyn ExpandDatabase) -> Edition;
     /// Returns the original file of this macro call hierarchy.
     fn original_file(self, db: &dyn ExpandDatabase) -> EditionedFileId;
 
@@ -293,6 +294,12 @@ pub trait HirFileIdExt {
 }
 
 impl HirFileIdExt for HirFileId {
+    fn edition(self, db: &dyn ExpandDatabase) -> Edition {
+        match self.repr() {
+            HirFileIdRepr::FileId(file_id) => file_id.edition(),
+            HirFileIdRepr::MacroFile(m) => m.macro_call_id.lookup(db).def.edition,
+        }
+    }
     fn original_file(self, db: &dyn ExpandDatabase) -> EditionedFileId {
         let mut file_id = self;
         loop {

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

@@ -1,5 +1,4 @@
 use crate::{utils, AssistContext, Assists};
-use hir::DescendPreference;
 use ide_db::{
     assists::{AssistId, AssistKind},
     syntax_helpers::{
@@ -40,10 +39,8 @@ pub(crate) fn extract_expressions_from_format_string(
     let tt = fmt_string.syntax().parent().and_then(ast::TokenTree::cast)?;
     let tt_delimiter = tt.left_delimiter_token()?.kind();
 
-    let expanded_t = ast::String::cast(
-        ctx.sema
-            .descend_into_macros_single(DescendPreference::SameKind, fmt_string.syntax().clone()),
-    )?;
+    let expanded_t =
+        ast::String::cast(ctx.sema.descend_into_macros_single_exact(fmt_string.syntax().clone()))?;
     if !is_format_string(&expanded_t) {
         return None;
     }

crates/ide/src/doc_links.rs

@@ -144,7 +144,7 @@ pub(crate) fn external_docs(
         kind if kind.is_trivia() => 0,
         _ => 1,
     })?;
-    let token = sema.descend_into_macros_single(DescendPreference::None, token);
+    let token = sema.descend_into_macros_single_exact(token);
 
     let node = token.parent()?;
     let definition = match_ast! {

crates/ide/src/extend_selection.rs

@@ -1,6 +1,6 @@
 use std::iter::successors;
 
-use hir::{DescendPreference, Semantics};
+use hir::Semantics;
 use ide_db::RootDatabase;
 use syntax::{
     algo::{self, skip_trivia_token},
@@ -140,10 +140,8 @@ fn extend_tokens_from_range(
 
     // compute original mapped token range
     let extended = {
-        let fst_expanded =
-            sema.descend_into_macros_single(DescendPreference::None, first_token.clone());
-        let lst_expanded =
-            sema.descend_into_macros_single(DescendPreference::None, last_token.clone());
+        let fst_expanded = sema.descend_into_macros_single_exact(first_token.clone());
+        let lst_expanded = sema.descend_into_macros_single_exact(last_token.clone());
         let mut lca =
             algo::least_common_ancestor(&fst_expanded.parent()?, &lst_expanded.parent()?)?;
         lca = shallowest_node(&lca);
@@ -157,7 +155,7 @@ fn extend_tokens_from_range(
     let validate = || {
         let extended = &extended;
         move |token: &SyntaxToken| -> bool {
-            let expanded = sema.descend_into_macros_single(DescendPreference::None, token.clone());
+            let expanded = sema.descend_into_macros_single_exact(token.clone());
             let parent = match expanded.parent() {
                 Some(it) => it,
                 None => return false,

crates/ide/src/goto_implementation.rs

@@ -10,7 +10,7 @@ use crate::{FilePosition, NavigationTarget, RangeInfo, TryToNav};
 
 // Feature: Go to Implementation
 //
-// Navigates to the impl blocks of types.
+// Navigates to the impl items of types.
 //
 // |===
 // | Editor  | Shortcut
@@ -32,48 +32,55 @@ pub(crate) fn goto_implementation(
         _ => 0,
     })?;
     let range = original_token.text_range();
-    let navs =
-        sema.descend_into_macros_single(DescendPreference::SameText, original_token)
-            .parent()
-            .and_then(ast::NameLike::cast)
-            .and_then(|node| match &node {
-                ast::NameLike::Name(name) => {
-                    NameClass::classify(&sema, name).and_then(|class| match class {
-                        NameClass::Definition(it) | NameClass::ConstReference(it) => Some(it),
-                        NameClass::PatFieldShorthand { .. } => None,
-                    })
-                }
-                ast::NameLike::NameRef(name_ref) => NameRefClass::classify(&sema, name_ref)
-                    .and_then(|class| match class {
-                        NameRefClass::Definition(def) => Some(def),
-                        NameRefClass::FieldShorthand { .. }
-                        | NameRefClass::ExternCrateShorthand { .. } => None,
-                    }),
-                ast::NameLike::Lifetime(_) => None,
-            })
-            .and_then(|def| {
-                let navs = match def {
-                    Definition::Trait(trait_) => impls_for_trait(&sema, trait_),
-                    Definition::Adt(adt) => impls_for_ty(&sema, adt.ty(sema.db)),
-                    Definition::TypeAlias(alias) => impls_for_ty(&sema, alias.ty(sema.db)),
-                    Definition::BuiltinType(builtin) => impls_for_ty(&sema, builtin.ty(sema.db)),
-                    Definition::Function(f) => {
-                        let assoc = f.as_assoc_item(sema.db)?;
-                        let name = assoc.name(sema.db)?;
-                        let trait_ = assoc.container_or_implemented_trait(sema.db)?;
-                        impls_for_trait_item(&sema, trait_, name)
+    let navs = sema
+        .descend_into_macros(DescendPreference::SameText, original_token)
+        .iter()
+        .filter_map(|token| {
+            token
+                .parent()
+                .and_then(ast::NameLike::cast)
+                .and_then(|node| match &node {
+                    ast::NameLike::Name(name) => {
+                        NameClass::classify(&sema, name).and_then(|class| match class {
+                            NameClass::Definition(it) | NameClass::ConstReference(it) => Some(it),
+                            NameClass::PatFieldShorthand { .. } => None,
+                        })
                     }
-                    Definition::Const(c) => {
-                        let assoc = c.as_assoc_item(sema.db)?;
-                        let name = assoc.name(sema.db)?;
-                        let trait_ = assoc.container_or_implemented_trait(sema.db)?;
-                        impls_for_trait_item(&sema, trait_, name)
-                    }
-                    _ => return None,
-                };
-                Some(navs)
-            })
-            .unwrap_or_default();
+                    ast::NameLike::NameRef(name_ref) => NameRefClass::classify(&sema, name_ref)
+                        .and_then(|class| match class {
+                            NameRefClass::Definition(def) => Some(def),
+                            NameRefClass::FieldShorthand { .. }
+                            | NameRefClass::ExternCrateShorthand { .. } => None,
+                        }),
+                    ast::NameLike::Lifetime(_) => None,
+                })
+                .and_then(|def| {
+                    let navs = match def {
+                        Definition::Trait(trait_) => impls_for_trait(&sema, trait_),
+                        Definition::Adt(adt) => impls_for_ty(&sema, adt.ty(sema.db)),
+                        Definition::TypeAlias(alias) => impls_for_ty(&sema, alias.ty(sema.db)),
+                        Definition::BuiltinType(builtin) => {
+                            impls_for_ty(&sema, builtin.ty(sema.db))
+                        }
+                        Definition::Function(f) => {
+                            let assoc = f.as_assoc_item(sema.db)?;
+                            let name = assoc.name(sema.db)?;
+                            let trait_ = assoc.container_or_implemented_trait(sema.db)?;
+                            impls_for_trait_item(&sema, trait_, name)
+                        }
+                        Definition::Const(c) => {
+                            let assoc = c.as_assoc_item(sema.db)?;
+                            let name = assoc.name(sema.db)?;
+                            let trait_ = assoc.container_or_implemented_trait(sema.db)?;
+                            impls_for_trait_item(&sema, trait_, name)
+                        }
+                        _ => return None,
+                    };
+                    Some(navs)
+                })
+        })
+        .flatten()
+        .collect();
 
     Some(RangeInfo { range, info: navs })
 }

crates/ide/src/signature_help.rs

@@ -4,10 +4,7 @@
 use std::collections::BTreeSet;
 
 use either::Either;
-use hir::{
-    AssocItem, DescendPreference, GenericParam, HirDisplay, ModuleDef, PathResolution, Semantics,
-    Trait,
-};
+use hir::{AssocItem, GenericParam, HirDisplay, ModuleDef, PathResolution, Semantics, Trait};
 use ide_db::{
     active_parameter::{callable_for_node, generic_def_for_node},
     documentation::{Documentation, HasDocs},
@@ -81,7 +78,7 @@ pub(crate) fn signature_help(
         // if the cursor is sandwiched between two space tokens and the call is unclosed
         // this prevents us from leaving the CallExpression
         .and_then(|tok| algo::skip_trivia_token(tok, Direction::Prev))?;
-    let token = sema.descend_into_macros_single(DescendPreference::None, token);
+    let token = sema.descend_into_macros_single_exact(token);
 
     for node in token.parent_ancestors() {
         match_ast! {

crates/ide/src/syntax_highlighting.rs

@@ -410,7 +410,8 @@ fn traverse(
                             })
                             .unwrap()
                     } else {
-                        sema.descend_into_macros_single(DescendPreference::SameKind, token)
+                        // FIXME: We should probably rank the tokens and find the most suitable?
+                        sema.descend_into_macros_single_exact(token)
                     };
                     match token.parent().and_then(ast::NameLike::cast) {
                         // Remap the token into the wrapping single token nodes

crates/ide/src/syntax_highlighting/test_data/highlight_macros.html

@@ -58,7 +58,7 @@
 <span class="brace">}</span>
 
 <span class="macro">def_fn</span><span class="macro_bang">!</span> <span class="brace macro">{</span>
-    <span class="keyword macro">fn</span> <span class="function declaration macro">bar</span><span class="parenthesis macro">(</span><span class="parenthesis macro">)</span> <span class="operator macro">-</span><span class="operator macro">&gt;</span> <span class="builtin_type macro">u32</span> <span class="brace macro">{</span>
+    <span class="keyword macro">fn</span> <span class="function declaration macro">bar</span><span class="parenthesis macro">(</span><span class="parenthesis macro">)</span> <span class="punctuation macro">-</span><span class="angle macro">&gt;</span> <span class="builtin_type macro">u32</span> <span class="brace macro">{</span>
         <span class="numeric_literal macro">100</span>
     <span class="brace macro">}</span>
 <span class="brace macro">}</span>
@@ -100,7 +100,7 @@
     <span class="brace">}</span><span class="semicolon">;</span>
 <span class="brace">}</span>
 
-<span class="macro default_library library">include</span><span class="macro_bang">!</span><span class="parenthesis macro">(</span><span class="macro default_library library macro">concat</span><span class="macro_bang macro">!</span><span class="parenthesis macro">(</span><span class="string_literal macro">"foo/"</span><span class="string_literal macro">,</span> <span class="string_literal macro">"foo.rs"</span><span class="parenthesis macro">)</span><span class="parenthesis macro">)</span><span class="semicolon">;</span>
+<span class="macro default_library library">include</span><span class="macro_bang">!</span><span class="parenthesis macro">(</span><span class="macro default_library library macro">concat</span><span class="macro_bang macro">!</span><span class="parenthesis macro">(</span><span class="string_literal macro">"foo/"</span><span class="comma macro">,</span> <span class="string_literal macro">"foo.rs"</span><span class="parenthesis macro">)</span><span class="parenthesis macro">)</span><span class="semicolon">;</span>
 
 <span class="keyword">struct</span> <span class="struct declaration">S</span><span class="angle">&lt;</span><span class="type_param declaration">T</span><span class="angle">&gt;</span><span class="parenthesis">(</span><span class="type_param">T</span><span class="parenthesis">)</span><span class="semicolon">;</span>
 <span class="keyword">fn</span> <span class="function declaration">main</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span>