Extend copied file mapping to all LSP requests returning locations

[loveucifer]

This addresses issue #2276 by ensuring that all LSP requests that return source file locations map copied header files back to their original locations, not just jump-to-definition.

Previously, only the definition request applied this mapping. Now, the following requests also adjust locations for copied files:

• textDocument/references
• textDocument/implementation
• workspace/symbol
• callHierarchy/prepare
• callHierarchy/incomingCalls
• callHierarchy/outgoingCalls
• typeHierarchy/prepare
• typeHierarchy/supertypes
• typeHierarchy/subtypes

This provides consistent navigation behavior, ensuring users are always taken to the original source files instead of build artifacts when possible.

[ahoppen]

Very cool 🤩 Excited to see this! I left a few comments inline.

[Copilot]

Pull request overview

This PR extends the remapping of copied header files to their original source locations across all LSP requests that return location information. Previously, only the textDocument/definition request applied this mapping; now all location-returning requests (references, implementation, workspace symbols, call hierarchy, and type hierarchy) consistently navigate users to original source files instead of build artifacts.

Key Changes:

• Added location remapping to references, implementation, and workspace symbol requests
• Implemented location remapping in call hierarchy (prepare, incoming, outgoing) operations
• Implemented location remapping in type hierarchy (prepare, supertypes, subtypes) operations

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
Tests/SourceKitLSPTests/CopiedHeaderTests.swift	New test file covering references, implementation, declaration, and workspace symbols in copied headers
Sources/SourceKitLSP/SourceKitLSPServer.swift	Extended location remapping to all LSP location-returning requests and refactored call/type hierarchy handling
Sources/ClangLanguageService/ClangLanguageService.swift	Added location remapping for declaration and rename requests
Sources/BuildServerIntegration/BuildServerManager.swift	Added helper methods for remapping locations in workspace edits, location links, and type hierarchy items

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[loveucifer]

hey @ahoppen can i get another review :)

[ahoppen]

Thanks, I left two more comments inline but I think a few of my last comments are still outstanding (see the ones that I didn’t mark as resolved). In particular, I don’t think that SourceKitLSPServer.swift should contain any large-scale edits for this change, it should just call to adjust methods in BuildServerManager to take copied files into account.

[loveucifer]

Thanks, I left two more comments inline but I think a few of my last comments are still outstanding (see the ones that I didn’t mark as resolved). In particular, I don’t think that SourceKitLSPServer.swift should contain any large-scale edits for this change, it should just call to adjust methods in BuildServerManager to take copied files into account.

got it thanks !

[ahoppen]

Thanks for the update. The PR looks pretty good now, I left a few more stylistic-ish comments inline.

[ahoppen]

Left a few more comments in the PR to simplify the diff a little further, but otherwise looks good to me.

[ahoppen]

Everything looks great to me. Thanks for addressing this issue 😍

[ahoppen]

@swift-ci Please test

[ahoppen]

@swift-ci Please test Windows

[loveucifer]

Everything looks great to me. Thanks for addressing this issue 😍

Thanks! This was my first contribution to Swift, and I loved the whole PR process

[rintaro]

(I'm asking around about the compiler crashes)

[rintaro]

I preserved the current state in https://github.com/rintaro/sourcekit-lsp/tree/PR-2385-crasher so compiler folks can look into it.
Feel free to modify the PR and try workaround if there's any.

[ahoppen]

I filed swiftlang/swift#86170 for the compiler crash. A workaround seems to be to refer to for … in instead of asyncCompactMap in prepareTypeHierarchy, eg. using the following diff. @loveucifer could you apply that and I’ll trigger CI again?

diff --git a/Sources/SourceKitLSP/SourceKitLSPServer.swift b/Sources/SourceKitLSP/SourceKitLSPServer.swift
index 80055d84..c92b7c68 100644
--- a/Sources/SourceKitLSP/SourceKitLSPServer.swift
+++ b/Sources/SourceKitLSP/SourceKitLSPServer.swift
@@ -2546,7 +2546,8 @@ extension SourceKitLSPServer {
       )
     }
 
-    let typeHierarchyItems = await usrs.asyncCompactMap { (usr) -> TypeHierarchyItem? in
+    var typeHierarchyItems: [TypeHierarchyItem] = []
+    for usr in usrs {
       guard let info = index.primaryDefinitionOrDeclarationOccurrence(ofUSR: usr) else {
         return nil
       }
@@ -2570,8 +2571,9 @@ extension SourceKitLSPServer {
       guard let item = indexToLSPTypeHierarchyItem2(definition: info, moduleName: moduleName, index: index) else {
         return nil
       }
-      return await workspace.buildServerManager.typeHierarchyItemAdjustedForCopiedFiles(item)
-    }.sorted(by: { $0.name < $1.name })
+      typeHierarchyItems.append(await workspace.buildServerManager.typeHierarchyItemAdjustedForCopiedFiles(item))
+    }
+    typeHierarchyItems.sort(by: { $0.name < $1.name })
 
     if typeHierarchyItems.isEmpty {
       // When returning an empty array, VS Code fails with the following two errors. Returning `nil` works around those

[loveucifer]

I filed swiftlang/swift#86170 for the compiler crash. A workaround seems to be to refer to for … in instead of asyncCompactMap in prepareTypeHierarchy, eg. using the following diff. @loveucifer could you apply that and I’ll trigger CI again?

diff --git a/Sources/SourceKitLSP/SourceKitLSPServer.swift b/Sources/SourceKitLSP/SourceKitLSPServer.swift
index 80055d84..c92b7c68 100644
--- a/Sources/SourceKitLSP/SourceKitLSPServer.swift
+++ b/Sources/SourceKitLSP/SourceKitLSPServer.swift
@@ -2546,7 +2546,8 @@ extension SourceKitLSPServer {
       )
     }
 
-    let typeHierarchyItems = await usrs.asyncCompactMap { (usr) -> TypeHierarchyItem? in
+    var typeHierarchyItems: [TypeHierarchyItem] = []
+    for usr in usrs {
       guard let info = index.primaryDefinitionOrDeclarationOccurrence(ofUSR: usr) else {
         return nil
       }
@@ -2570,8 +2571,9 @@ extension SourceKitLSPServer {
       guard let item = indexToLSPTypeHierarchyItem2(definition: info, moduleName: moduleName, index: index) else {
         return nil
       }
-      return await workspace.buildServerManager.typeHierarchyItemAdjustedForCopiedFiles(item)
-    }.sorted(by: { $0.name < $1.name })
+      typeHierarchyItems.append(await workspace.buildServerManager.typeHierarchyItemAdjustedForCopiedFiles(item))
+    }
+    typeHierarchyItems.sort(by: { $0.name < $1.name })
 
     if typeHierarchyItems.isEmpty {
       // When returning an empty array, VS Code fails with the following two errors. Returning `nil` works around those

got it doing it rn

[loveucifer]

hey @ahoppen sorry if this is the wrong place to ask is there a server or communication channel for this repo

[ahoppen]

@swift-ci Please test

[ahoppen]

sorry if this is the wrong place to ask is there a server or communication channel for this repo

For anything that’s related to a specific issue or a code change, GitHub is really the best communication channel. For anything more broad, you can also post in the SourceKit-LSP category on the Swift Forums.

[loveucifer]

seems like its still failing :(

[ahoppen]

Looks like we need to apply the same trick in a couple new places. It builds with the following diff applied using swift-DEVELOPMENT-SNAPSHOT-2025-11-26-a. Could you apply it to your PR. And sorry for this churn.

Diff

diff --git a/Sources/SourceKitLSP/SourceKitLSPServer.swift b/Sources/SourceKitLSP/SourceKitLSPServer.swift
index dbf4896f..3542baf1 100644
--- a/Sources/SourceKitLSP/SourceKitLSPServer.swift
+++ b/Sources/SourceKitLSP/SourceKitLSPServer.swift
@@ -2281,15 +2281,17 @@ extension SourceKitLSPServer {
 
     // Only return a single call hierarchy item. Returning multiple doesn't make sense because they will all have the
     // same USR (because we query them by USR) and will thus expand to the exact same call hierarchy.
-    let callHierarchyItems = await usrs.asyncCompactMap { (usr) -> CallHierarchyItem? in
+    var callHierarchyItems: [CallHierarchyItem] = []
+    for usr in usrs {
       guard let definition = index.primaryDefinitionOrDeclarationOccurrence(ofUSR: usr) else {
-        return nil
+        continue
       }
       guard let item = indexToLSPCallHierarchyItem2(definition: definition, index: index) else {
-        return nil
+        continue
       }
-      return await workspace.buildServerManager.callHierarchyItemAdjustedForCopiedFiles(item)
-    }.sorted(by: { Location(uri: $0.uri, range: $0.range) < Location(uri: $1.uri, range: $1.range) })
+      callHierarchyItems.append(await workspace.buildServerManager.callHierarchyItemAdjustedForCopiedFiles(item))
+    }
+    callHierarchyItems.sort(by: { Location(uri: $0.uri, range: $0.range) < Location(uri: $1.uri, range: $1.range) })
 
     // Ideally, we should show multiple symbols. But VS Code fails to display call hierarchies with multiple root items,
     // failing with `Cannot read properties of undefined (reading 'map')`. Pick the first one.
@@ -2358,24 +2360,25 @@ extension SourceKitLSPServer {
       return self.indexToLSPCallHierarchyItem(definition: definition, index: index)
     }
 
-    let calls = await callersToCalls.asyncCompactMap { (caller, callsList) -> CallHierarchyIncomingCall? in
+    var calls: [CallHierarchyIncomingCall] = []
+    for (caller, callsList) in callersToCalls {
       // Resolve the caller's definition to find its location
       guard let definition = index.primaryDefinitionOrDeclarationOccurrence(ofUSR: caller.usr) else {
-        return nil
+        continue
       }
 
       let locations = callsList.compactMap { indexToLSPLocation2($0.location) }.sorted()
       let remappedLocations = await workspace.buildServerManager.locationsAdjustedForCopiedFiles(locations)
       guard !remappedLocations.isEmpty else {
-        return nil
+        continue
       }
 
       guard let item = indexToLSPCallHierarchyItem2(definition: definition, index: index) else {
-        return nil
+        continue
       }
       let remappedItem = await workspace.buildServerManager.callHierarchyItemAdjustedForCopiedFiles(item)
 
-      return CallHierarchyIncomingCall(from: remappedItem, fromRanges: remappedLocations.map(\.range))
+      calls.append(CallHierarchyIncomingCall(from: remappedItem, fromRanges: remappedLocations.map(\.range)))
     }
     return calls.sorted(by: { $0.from.name < $1.from.name })
   }
@@ -2404,26 +2407,27 @@ extension SourceKitLSPServer {
     let callableUsrs = [data.usr] + index.occurrences(relatedToUSR: data.usr, roles: .accessorOf).map(\.symbol.usr)
     let callOccurrences = callableUsrs.flatMap { index.occurrences(relatedToUSR: $0, roles: .containedBy) }
       .filter(\.shouldShowInCallHierarchy)
-    let calls = await callOccurrences.asyncCompactMap { occurrence -> CallHierarchyOutgoingCall? in
+    var calls: [CallHierarchyOutgoingCall] = []
+    for occurrence in callOccurrences {
       guard occurrence.symbol.kind.isCallable else {
-        return nil
+        continue
       }
       guard let location = indexToLSPLocation2(occurrence.location) else {
-        return nil
+        continue
       }
       let remappedLocation = await workspace.buildServerManager.locationAdjustedForCopiedFiles(location)
 
       // Resolve the callee's definition to find its location
       guard let definition = index.primaryDefinitionOrDeclarationOccurrence(ofUSR: occurrence.symbol.usr) else {
-        return nil
+        continue
       }
 
       guard let item = indexToLSPCallHierarchyItem2(definition: definition, index: index) else {
-        return nil
+        continue
       }
       let remappedItem = await workspace.buildServerManager.callHierarchyItemAdjustedForCopiedFiles(item)
 
-      return CallHierarchyOutgoingCall(to: remappedItem, fromRanges: [remappedLocation.range])
+      calls.append(CallHierarchyOutgoingCall(to: remappedItem, fromRanges: [remappedLocation.range]))
     }
     return calls.sorted(by: { $0.to.name < $1.to.name })
   }
@@ -2624,17 +2628,18 @@ extension SourceKitLSPServer {
 
     // Convert occurrences to type hierarchy items
     let occurs = baseOccurs + retroactiveConformanceOccurs
-    let types = await occurs.asyncCompactMap { occurrence -> TypeHierarchyItem? in
+    var types: [TypeHierarchyItem] = []
+    for occurrence in occurs {
       // Resolve the supertype's definition to find its location
       guard let definition = index.primaryDefinitionOrDeclarationOccurrence(ofUSR: occurrence.symbol.usr) else {
-        return nil
+        continue
       }
 
       let moduleName = definition.location.moduleName
       guard let item = indexToLSPTypeHierarchyItem2(definition: definition, moduleName: moduleName, index: index) else {
-        return nil
+        continue
       }
-      return await workspace.buildServerManager.typeHierarchyItemAdjustedForCopiedFiles(item)
+      types.append(await workspace.buildServerManager.typeHierarchyItemAdjustedForCopiedFiles(item))
     }
     return types.sorted(by: { $0.name < $1.name })
   }
@@ -2664,7 +2669,8 @@ extension SourceKitLSPServer {
     }
 
     // Convert occurrences to type hierarchy items
-    let types = await occurs.asyncCompactMap { occurrence -> TypeHierarchyItem? in
+    var types: [TypeHierarchyItem] = []
+    for occurrence in occurs {
       if occurrence.relations.count > 1 {
         // An occurrence with a `baseOf` or `extendedBy` relation is an occurrence inside an inheritance clause.
         // Such an occurrence can only be the source of a single type, namely the one that the inheritance clause belongs
@@ -2672,19 +2678,19 @@ extension SourceKitLSPServer {
         logger.fault("Expected at most extendedBy or baseOf relation but got \(occurrence.relations.count)")
       }
       guard let related = occurrence.relations.sorted().first else {
-        return nil
+        continue
       }
 
       // Resolve the subtype's definition to find its location
       guard let definition = index.primaryDefinitionOrDeclarationOccurrence(ofUSR: related.symbol.usr) else {
-        return nil
+        continue
       }
 
       let moduleName = definition.location.moduleName
       guard let item = indexToLSPTypeHierarchyItem2(definition: definition, moduleName: moduleName, index: index) else {
-        return nil
+        continue
       }
-      return await workspace.buildServerManager.typeHierarchyItemAdjustedForCopiedFiles(item)
+      types.append(await workspace.buildServerManager.typeHierarchyItemAdjustedForCopiedFiles(item))
     }
     return types.sorted { $0.name < $1.name }
   }

[loveucifer]

@ahoppen hope this fixes it :3

[rintaro]

@swift-ci Please test