Fixing linking issue

Author: grantnelson-wf

build/context.go

@@ -320,7 +320,7 @@ func overlayCtx(e Env) *simpleCtx {
 // packages in case they are not present in the user's source tree.
 func gopherjsCtx(e Env) *simpleCtx {
 	gopherjsRoot := filepath.Join(e.GOROOT, "src", "github.com", "gopherjs", "gopherjs")
-	return embeddedCtx(&withPrefix{gopherjspkg.FS, gopherjsRoot}, e)
+	return embeddedCtx(&withPrefix{fs: gopherjspkg.FS, prefix: gopherjsRoot}, e)
 }
 
 // goCtx creates simpleCtx that imports from the real file system GOROOT, GOPATH

compiler/astutil/astutil.go

@@ -406,6 +406,18 @@ func squeeze[E ast.Node, S ~[]E](s S) S {
 	return s[:dest]
 }
 
+func updateFileComments(file *ast.File) {
+	file.Comments = nil // clear this first so ast.Inspect doesn't walk it.
+	remComments := []*ast.CommentGroup{}
+	ast.Inspect(file, func(n ast.Node) bool {
+		if cg, ok := n.(*ast.CommentGroup); ok {
+			remComments = append(remComments, cg)
+		}
+		return true
+	})
+	file.Comments = remComments
+}
+
 // FinalizeRemovals fully removes any declaration, specification, imports
 // that have been set to nil. This will also remove any unassociated comment
 // groups, including the comments from removed code.
@@ -454,7 +466,8 @@ func FinalizeRemovals(file *ast.File) {
 	}
 
 	file.Imports = squeeze(file.Imports)
-	file.Comments = nil
+
+	updateFileComments(file)
 }
 
 // ConcatenateFiles will concatenate the given tailing files onto the
@@ -478,13 +491,7 @@ func FinalizeRemovals(file *ast.File) {
 //   - The tails will not be modified, however the nodes from the tails will be
 //     added into the target file so modifications to the tails after
 //     concatenation could cause the target file to be in an invalid state.
-//   - This will set the deprecated Unresolved fields to nil, see [ast.Object].
-//   - This will set the deprecated Scope to nil, see [ast.Object].
-//   - This will set the full list of Comments to nil.
-//     The full list of Comments expects the comments to use Pos that follow
-//     sequentially when formatting. That may not be the case after
-//     concatenation. By removing the full list tools like Format will use the
-//     comments on the nodes instead.
+//   - This will not modify the deprecated Unresolved or file Scope fields.
 //   - Any comments on import declarations will be lost since the imports will
 //     be merged into a single new import declaration. The comments on the
 //     individual import specs will be preserved.
@@ -573,11 +580,6 @@ func ConcatenateFiles(file *ast.File, tails ...*ast.File) error {
 	}
 	file.Decls = decls
 
-	// Remove the full comments list since they are no longer valid.
-	file.Comments = nil
-
-	// Remove the deprecated fields from the file, see [ast.Object].
-	file.Unresolved = nil
-	file.Scope = nil
+	updateFileComments(file)
 	return nil
 }

compiler/astutil/astutil_test.go

@@ -1098,13 +1098,21 @@ func TestConcatenateFiles(t *testing.T) {
 				return
 			}
 
+			// The formatter expects the comment line numbers to be consecutive
+			// so that layout is preserved. We can't guarantee that the line
+			// numbers are correct after appending the files, which is fine
+			// as long as we aren't trying to format it.
+			// Setting the file comments to nil will force the formatter to use
+			// the comments on the AST nodes when the node is reached which
+			// gives a more accurate view of the concatenated file.
+			headFile.Comments = nil
 			got := srctesting.Format(t, st.FileSet, headFile)
 			if len(test.want) == 0 {
 				t.Errorf("Expected an error but got AST:\n\tgot:  %q\n\twant: %q", got, test.expErr)
 				return
 			}
 
-			// parse and format the expected result so that formatting matches
+			// parse and format the expected result so that formatting matches.
 			wantFile := st.Parse("testWant.go", test.want)
 			want := srctesting.Format(t, st.FileSet, wantFile)
 			if got != want {