From 2256a69de37c7a7cec0ac235fca6cc84bd7d9b39 Mon Sep 17 00:00:00 2001
From: Qing Yang <yangq.nj@gmail.com>
Date: Thu, 30 Sep 2021 11:44:08 -0700
Subject: [PATCH] [Swift] Add -debug-prefix-map to map source file (#37)

---
 src/com/facebook/buck/swift/SwiftCompile.java | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/com/facebook/buck/swift/SwiftCompile.java b/src/com/facebook/buck/swift/SwiftCompile.java
index 636e7191094..0efdc82fe20 100644
--- a/src/com/facebook/buck/swift/SwiftCompile.java
+++ b/src/com/facebook/buck/swift/SwiftCompile.java
@@ -315,7 +315,9 @@ private SwiftCompileStep makeCompileStep(SourcePathResolverAdapter resolver) {
         "-emit-objc-header-path",
         headerPath.toString(),
         "-o",
-        objectFilePath.toString());
+        objectFilePath.toString(),
+        "-debug-prefix-map",
+        String.format("%s=.", getProjectFilesystem().getRootPath()));
 
     if (shouldEmitSwiftdocs) {
       compilerCommand.add("-emit-module-doc", "-emit-module-doc-path", swiftdocPath.toString());