diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index f3f8a86209..d225a10254 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -131,7 +131,7 @@ namespace ts {
         };
 
         function emitSourceFileOrBundle({ jsFilePath, sourceMapFilePath, declarationFilePath, declarationMapPath, buildInfoPath }: EmitFileNames, sourceFileOrBundle: SourceFile | Bundle) {
-            if (buildInfoPath && !emitOnlyDtsFiles) buildInfo = { js: [], dts: [] };
+            if (buildInfoPath && !emitOnlyDtsFiles) buildInfo = { js: [], dts: [], commonSourceDirectory: host.getCommonSourceDirectory() };
             emitJsFileOrBundle(sourceFileOrBundle, jsFilePath, sourceMapFilePath, buildInfo && buildInfo.js);
             emitDeclarationFileOrBundle(sourceFileOrBundle, declarationFilePath, declarationMapPath, buildInfo && buildInfo.dts);
             // Write bundled offset information if applicable
diff --git a/src/compiler/factory.ts b/src/compiler/factory.ts
index fdd93765cf..7d6f22025e 100644
--- a/src/compiler/factory.ts
+++ b/src/compiler/factory.ts
@@ -2673,8 +2673,8 @@ namespace ts {
                 sourceMapText: { get() { return mapPathOrType === "js" ? textOrInputFiles.javascriptMapText : textOrInputFiles.declarationMapText; } },
             });
 
-            const sections = textOrInputFiles.buildInfo ? mapPathOrType === "js" ? textOrInputFiles.buildInfo.js : textOrInputFiles.buildInfo.dts : undefined;
-            if (sections) {
+            if (textOrInputFiles.buildInfo) {
+                const sections = mapPathOrType === "js" ? textOrInputFiles.buildInfo.js : textOrInputFiles.buildInfo.dts;
                 for (const section of sections) {
                     switch (section.kind) {
                         case BundleFileSectionKind.Prologue:
@@ -2777,6 +2777,14 @@ namespace ts {
         declarationMapTextOrBuildInfoPath?: string
     ): InputFiles {
         const node = <InputFiles>createNode(SyntaxKind.InputFiles);
+        let buildInfo: BuildInfo | false;
+        const getBuildInfo = (getText: () => string | undefined) => {
+            if (buildInfo === undefined) {
+                const result = getText();
+                buildInfo = result !== undefined ? JSON.parse(result) as BuildInfo : false;
+            }
+            return buildInfo || undefined;
+        };
         if (!isString(javascriptTextOrReadFileText)) {
             const cache = createMap<string | false>();
             const textGetter = (path: string | undefined) => {
@@ -2792,10 +2800,6 @@ namespace ts {
                 const result = textGetter(path);
                 return result !== undefined ? result : `/* Input file ${path} was missing */\r\n`;
             };
-            const jsonGetter = (path: string | undefined) => {
-                const result = textGetter(path);
-                return result !== undefined ? JSON.parse(result) as BuildInfo : undefined;
-            };
             node.javascriptPath = declarationTextOrJavascriptPath;
             node.javascriptMapPath = javascriptMapPath;
             node.declarationPath = Debug.assertDefined(javascriptMapTextOrDeclarationPath);
@@ -2806,7 +2810,7 @@ namespace ts {
                 javascriptMapText: { get() { return textGetter(javascriptMapPath); } }, // TODO:: if there is inline sourceMap in jsFile, use that
                 declarationText: { get() { return definedTextGetter(Debug.assertDefined(javascriptMapTextOrDeclarationPath)); } },
                 declarationMapText: { get() { return textGetter(declarationMapPath); } }, // TODO:: if there is inline sourceMap in dtsFile, use that
-                buildInfo: { get() { return jsonGetter(declarationMapTextOrBuildInfoPath); } }
+                buildInfo: { get() { return getBuildInfo(() => textGetter(declarationMapTextOrBuildInfoPath)); } }
             });
         }
         else {
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 19d97d7bd5..8066fe3107 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -5531,8 +5531,9 @@ namespace ts {
     export type BundleFileInfo = BundleFileSection[];
     /* @internal */
     export interface BuildInfo {
-        js?: BundleFileInfo;
-        dts?: BundleFileInfo;
+        js: BundleFileInfo;
+        dts: BundleFileInfo;
+        commonSourceDirectory: string;
     }
 
     export interface PrintHandlers {
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/baseline-sectioned-sourcemaps.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/baseline-sectioned-sourcemaps.js
index 6c3b6f3156..72e1e54c38 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/baseline-sectioned-sourcemaps.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/baseline-sectioned-sourcemaps.js
@@ -23,7 +23,8 @@
       "end": 198,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -389,7 +390,8 @@ console.log(s);
       "end": 406,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/emitHelpers-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/emitHelpers-in-all-projects.js
index cd2b55e05c..11607e3970 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/emitHelpers-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/emitHelpers-in-all-projects.js
@@ -29,7 +29,8 @@
       "end": 249,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -494,7 +495,8 @@ const { b, ...rest } = { a: 10, b: 30, yy: 30 };
       "end": 561,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/emitHelpers-in-only-one-dependency-project.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/emitHelpers-in-only-one-dependency-project.js
index f9d448b1c7..669df32f3d 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/emitHelpers-in-only-one-dependency-project.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/emitHelpers-in-only-one-dependency-project.js
@@ -23,7 +23,8 @@
       "end": 249,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -432,7 +433,8 @@ function forfirstfirst_PART1Rest() { }
       "end": 510,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-emitHelpers-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-emitHelpers-in-all-projects.js
index 3ca9bc3548..9246e40f10 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-emitHelpers-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-emitHelpers-in-all-projects.js
@@ -41,7 +41,8 @@
       "end": 313,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -691,7 +692,8 @@ const { b, ...rest } = { a: 10, b: 30, yy: 30 };
       "end": 755,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-emitHelpers-in-different-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-emitHelpers-in-different-projects.js
index 6880d778ba..ed6560487b 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-emitHelpers-in-different-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-emitHelpers-in-different-projects.js
@@ -29,7 +29,8 @@
       "end": 249,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -506,7 +507,8 @@ const { b, ...rest } = { a: 10, b: 30, yy: 30 };
       "end": 574,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-prologues-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-prologues-in-all-projects.js
index 247016463b..6b4ea289d5 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-prologues-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-prologues-in-all-projects.js
@@ -35,7 +35,8 @@
       "end": 198,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -443,7 +444,8 @@ console.log(s);
       "end": 406,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-prologues-in-different-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-prologues-in-different-projects.js
index 1442f9390b..305cc2594c 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-prologues-in-different-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/multiple-prologues-in-different-projects.js
@@ -29,7 +29,8 @@
       "end": 198,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -415,7 +416,8 @@ console.log(s);
       "end": 406,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/shebang-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/shebang-in-all-projects.js
index 1831f3338a..29329cd171 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/shebang-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/shebang-in-all-projects.js
@@ -23,7 +23,8 @@
       "end": 231,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -397,7 +398,8 @@ console.log(s);
       "end": 439,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/shebang-in-only-one-dependency-project.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/shebang-in-only-one-dependency-project.js
index b16a3845f8..41319b4ad6 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/shebang-in-only-one-dependency-project.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/shebang-in-only-one-dependency-project.js
@@ -23,7 +23,8 @@
       "end": 198,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -389,7 +390,8 @@ console.log(s);
       "end": 441,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/strict-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/strict-in-all-projects.js
index 792335c92a..61f629d50c 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/strict-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/strict-in-all-projects.js
@@ -29,7 +29,8 @@
       "end": 198,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -403,7 +404,8 @@ console.log(s);
       "end": 406,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/strict-in-one-dependency.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/strict-in-one-dependency.js
index 62d32130ca..a7bc809fa0 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/strict-in-one-dependency.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/strict-in-one-dependency.js
@@ -23,7 +23,8 @@
       "end": 198,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -395,7 +396,8 @@ console.log(s);
       "end": 406,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/triple-slash-refs-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/triple-slash-refs-in-all-projects.js
index 7f560a1bd6..c4ec2ca1da 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/triple-slash-refs-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/triple-slash-refs-in-all-projects.js
@@ -29,7 +29,8 @@
       "end": 293,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -470,7 +471,8 @@ console.log(s);
       "end": 722,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/triple-slash-refs-in-one-project.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/triple-slash-refs-in-one-project.js
index 33f188e2ef..d9c99b64fe 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/triple-slash-refs-in-one-project.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/triple-slash-refs-in-one-project.js
@@ -23,7 +23,8 @@
       "end": 198,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -395,7 +396,8 @@ console.log(s);
       "end": 517,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js
index 6c3b6f3156..72e1e54c38 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-changes/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js
@@ -23,7 +23,8 @@
       "end": 198,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -389,7 +390,8 @@ console.log(s);
       "end": 406,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/baseline-sectioned-sourcemaps.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/baseline-sectioned-sourcemaps.js
index 96feb8860f..0c61cc9833 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/baseline-sectioned-sourcemaps.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/baseline-sectioned-sourcemaps.js
@@ -23,7 +23,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -274,7 +275,8 @@ console.log(s);
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/emitHelpers-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/emitHelpers-in-all-projects.js
index 63b2a24a57..408eaa1c87 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/emitHelpers-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/emitHelpers-in-all-projects.js
@@ -29,7 +29,8 @@
       "end": 250,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -358,7 +359,8 @@ const { b, ...rest } = { a: 10, b: 30, yy: 30 };
       "end": 562,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/emitHelpers-in-only-one-dependency-project.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/emitHelpers-in-only-one-dependency-project.js
index a2c2bc5e1f..0e513ac7f9 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/emitHelpers-in-only-one-dependency-project.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/emitHelpers-in-only-one-dependency-project.js
@@ -23,7 +23,8 @@
       "end": 250,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -298,7 +299,8 @@ function forfirstfirst_PART1Rest() { }console.log(s);
       "end": 511,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-emitHelpers-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-emitHelpers-in-all-projects.js
index 2e511baca4..813484db7b 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-emitHelpers-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-emitHelpers-in-all-projects.js
@@ -41,7 +41,8 @@
       "end": 314,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -524,7 +525,8 @@ const { b, ...rest } = { a: 10, b: 30, yy: 30 };
       "end": 756,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-emitHelpers-in-different-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-emitHelpers-in-different-projects.js
index c99ff7270b..c56a1577b3 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-emitHelpers-in-different-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-emitHelpers-in-different-projects.js
@@ -29,7 +29,8 @@
       "end": 250,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -370,7 +371,8 @@ const { b, ...rest } = { a: 10, b: 30, yy: 30 };
       "end": 575,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-prologues-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-prologues-in-all-projects.js
index aa05b6d0d7..3f865dc361 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-prologues-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-prologues-in-all-projects.js
@@ -35,7 +35,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -327,7 +328,8 @@ console.log(s);
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-prologues-in-different-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-prologues-in-different-projects.js
index 94125dc701..ddfa56eb12 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-prologues-in-different-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/multiple-prologues-in-different-projects.js
@@ -29,7 +29,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -300,7 +301,8 @@ console.log(s);
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/shebang-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/shebang-in-all-projects.js
index 6bde05dae9..2adac79013 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/shebang-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/shebang-in-all-projects.js
@@ -23,7 +23,8 @@
       "end": 232,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -279,7 +280,8 @@ console.log(s);
       "end": 440,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/shebang-in-only-one-dependency-project.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/shebang-in-only-one-dependency-project.js
index 9d4be56890..691c7b8509 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/shebang-in-only-one-dependency-project.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/shebang-in-only-one-dependency-project.js
@@ -23,7 +23,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -274,7 +275,8 @@ console.log(s);
       "end": 442,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/strict-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/strict-in-all-projects.js
index 3960c5a693..f09d0b8ad8 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/strict-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/strict-in-all-projects.js
@@ -29,7 +29,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -288,7 +289,8 @@ console.log(s);
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/strict-in-one-dependency.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/strict-in-one-dependency.js
index b64e7cdf3f..aefb1ae0dc 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/strict-in-one-dependency.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/strict-in-one-dependency.js
@@ -23,7 +23,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -280,7 +281,8 @@ console.log(s);
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/triple-slash-refs-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/triple-slash-refs-in-all-projects.js
index 03eea70e34..697d86b69d 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/triple-slash-refs-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/triple-slash-refs-in-all-projects.js
@@ -29,7 +29,8 @@
       "end": 294,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -327,7 +328,8 @@ console.log(s);
       "end": 723,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/triple-slash-refs-in-one-project.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/triple-slash-refs-in-one-project.js
index 523bf4aec3..eaa2446743 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/triple-slash-refs-in-one-project.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/triple-slash-refs-in-one-project.js
@@ -23,7 +23,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -280,7 +281,8 @@ console.log(s);
       "end": 518,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js
index 96feb8860f..0c61cc9833 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-declaration-doesnt-change/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js
@@ -23,7 +23,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.js]
@@ -274,7 +275,8 @@ console.log(s);
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.js]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/emitHelpers-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/emitHelpers-in-all-projects.js
index 74007aefda..9b9c17b7b2 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/emitHelpers-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/emitHelpers-in-all-projects.js
@@ -23,7 +23,8 @@
       "end": 250,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts.map]
@@ -420,7 +421,8 @@ function forfirstfirst_PART1Rest() { }
       "end": 562,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts.map]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/emitHelpers-in-only-one-dependency-project.js b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/emitHelpers-in-only-one-dependency-project.js
index b0450ac434..b0701bb00d 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/emitHelpers-in-only-one-dependency-project.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/emitHelpers-in-only-one-dependency-project.js
@@ -29,7 +29,8 @@
       "end": 250,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts.map]
@@ -482,7 +483,8 @@ const { b, ...rest } = { a: 10, b: 30, yy: 30 };
       "end": 511,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts.map]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-emitHelpers-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-emitHelpers-in-all-projects.js
index 91fede7417..f85f38aa71 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-emitHelpers-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-emitHelpers-in-all-projects.js
@@ -35,7 +35,8 @@
       "end": 314,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts.map]
@@ -616,7 +617,8 @@ function forfirstfirst_PART1Rest() { }
       "end": 756,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts.map]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-emitHelpers-in-different-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-emitHelpers-in-different-projects.js
index b706a28b96..20f337067f 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-emitHelpers-in-different-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-emitHelpers-in-different-projects.js
@@ -23,7 +23,8 @@
       "end": 250,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts.map]
@@ -432,7 +433,8 @@ function forfirstfirst_PART1Rest() { }
       "end": 575,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts.map]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-prologues-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-prologues-in-all-projects.js
index 71132fb857..b2799e902c 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-prologues-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-prologues-in-all-projects.js
@@ -41,7 +41,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts.map]
@@ -459,7 +460,8 @@ console.log(s);
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts.map]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-prologues-in-different-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-prologues-in-different-projects.js
index bd96cfc2d3..571b1a8619 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-prologues-in-different-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/multiple-prologues-in-different-projects.js
@@ -35,7 +35,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts.map]
@@ -432,7 +433,8 @@ console.log(s);
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts.map]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/strict-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/strict-in-all-projects.js
index 745ad112b3..b479914329 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/strict-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/strict-in-all-projects.js
@@ -35,7 +35,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts.map]
@@ -420,7 +421,8 @@ console.log(s);
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts.map]
diff --git a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/strict-in-one-dependency.js b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/strict-in-one-dependency.js
index e6e136da0a..41455f579e 100644
--- a/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/strict-in-one-dependency.js
+++ b/tests/baselines/reference/tsbuild/outFile/incremental-headers-change/buildInfo/strict-in-one-dependency.js
@@ -29,7 +29,8 @@
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts.map]
@@ -412,7 +413,8 @@ console.log(s);
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts.map]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/baseline-sectioned-sourcemaps.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/baseline-sectioned-sourcemaps.js
index 6c0101d3b6..c2d6e8e882 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/baseline-sectioned-sourcemaps.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/baseline-sectioned-sourcemaps.js
@@ -23,7 +23,8 @@
       "end": 143,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -436,7 +437,8 @@ sourceFile:../second/second_part2.ts
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -788,7 +790,8 @@ sourceFile:../first_part3.ts
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/emitHelpers-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/emitHelpers-in-all-projects.js
index 8a0be56b51..ca76edcb0e 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/emitHelpers-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/emitHelpers-in-all-projects.js
@@ -29,7 +29,8 @@
       "end": 196,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -537,7 +538,8 @@ sourceFile:../second/second_part2.ts
       "end": 250,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -1018,7 +1020,8 @@ const { b, ...rest } = { a: 10, b: 30, yy: 30 };
       "end": 562,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/emitHelpers-in-only-one-dependency-project.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/emitHelpers-in-only-one-dependency-project.js
index 135e57770b..f5f3ad0a4c 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/emitHelpers-in-only-one-dependency-project.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/emitHelpers-in-only-one-dependency-project.js
@@ -29,7 +29,8 @@
       "end": 196,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -531,7 +532,8 @@ sourceFile:../second/second_part2.ts
       "end": 250,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -956,7 +958,8 @@ const { b, ...rest } = { a: 10, b: 30, yy: 30 };
       "end": 511,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-emitHelpers-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-emitHelpers-in-all-projects.js
index 39a7f88acc..4be82144ed 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-emitHelpers-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-emitHelpers-in-all-projects.js
@@ -41,7 +41,8 @@
       "end": 262,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -736,7 +737,8 @@ sourceFile:../second/second_part2.ts
       "end": 314,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -1461,7 +1463,8 @@ secondsecond_part2Spread(...[10, 20, 30]);
       "end": 756,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-emitHelpers-in-different-projects.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-emitHelpers-in-different-projects.js
index 82bbcd53e0..d40d8e4bb5 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-emitHelpers-in-different-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-emitHelpers-in-different-projects.js
@@ -35,7 +35,8 @@
       "end": 209,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -629,7 +630,8 @@ sourceFile:../second/second_part2.ts
       "end": 250,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -1141,7 +1143,8 @@ secondsecond_part1Spread(...[10, 20, 30]);
       "end": 575,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-prologues-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-prologues-in-all-projects.js
index 6a2b72a717..5bdcce80d2 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-prologues-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-prologues-in-all-projects.js
@@ -41,7 +41,8 @@
       "end": 143,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -505,7 +506,8 @@ sourceFile:../second/second_part2.ts
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -977,7 +979,8 @@ class C {
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-prologues-in-different-projects.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-prologues-in-different-projects.js
index 469c10d79c..e79910a6e7 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-prologues-in-different-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/multiple-prologues-in-different-projects.js
@@ -35,7 +35,8 @@
       "end": 143,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -491,7 +492,8 @@ sourceFile:../second/second_part2.ts
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -909,7 +911,8 @@ class C {
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/shebang-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/shebang-in-all-projects.js
index d86d983356..8992996ae6 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/shebang-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/shebang-in-all-projects.js
@@ -23,7 +23,8 @@
       "end": 178,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -442,7 +443,8 @@ sourceFile:../second/second_part2.ts
       "end": 232,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -836,7 +838,8 @@ namespace N {
       "end": 440,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/shebang-in-only-one-dependency-project.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/shebang-in-only-one-dependency-project.js
index d79db2f6f9..e40f051d5c 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/shebang-in-only-one-dependency-project.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/shebang-in-only-one-dependency-project.js
@@ -23,7 +23,8 @@
       "end": 178,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -442,7 +443,8 @@ sourceFile:../second/second_part2.ts
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -809,7 +811,8 @@ namespace N {
       "end": 442,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/strict-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/strict-in-all-projects.js
index e8c8f98b3f..e6942131bb 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/strict-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/strict-in-all-projects.js
@@ -29,7 +29,8 @@
       "end": 143,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -450,7 +451,8 @@ sourceFile:../second/second_part2.ts
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -850,7 +852,8 @@ sourceFile:../first_part3.ts
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/strict-in-one-dependency.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/strict-in-one-dependency.js
index af887443f4..6dbc9e86b0 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/strict-in-one-dependency.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/strict-in-one-dependency.js
@@ -29,7 +29,8 @@
       "end": 143,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -444,7 +445,8 @@ sourceFile:../second/second_part2.ts
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -820,7 +822,8 @@ sourceFile:../first_part3.ts
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/triple-slash-refs-in-all-projects.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/triple-slash-refs-in-all-projects.js
index c17e74732f..af56212d40 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/triple-slash-refs-in-all-projects.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/triple-slash-refs-in-all-projects.js
@@ -29,7 +29,8 @@
       "end": 248,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -502,7 +503,8 @@ sourceFile:../second/second_part2.ts
       "end": 294,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -957,7 +959,8 @@ declare class secondsecond_part1 { }
       "end": 723,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/triple-slash-refs-in-one-project.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/triple-slash-refs-in-one-project.js
index 43a5e66bb1..7268632233 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/triple-slash-refs-in-one-project.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/triple-slash-refs-in-one-project.js
@@ -29,7 +29,8 @@
       "end": 248,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -496,7 +497,8 @@ sourceFile:../second/second_part2.ts
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -873,7 +875,8 @@ declare class secondsecond_part1 { }
       "end": 518,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]
diff --git a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js
index 10d9b4fa19..317d258f82 100644
--- a/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js
+++ b/tests/baselines/reference/tsbuild/outFile/initial-Build/buildInfo/when-final-project-is-not-composite-but-uses-project-references.js
@@ -23,7 +23,8 @@
       "end": 143,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/second/"
 }
 
 //// [/src/2/second-output.d.ts]
@@ -436,7 +437,8 @@ sourceFile:../second/second_part2.ts
       "end": 199,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/first/"
 }
 
 //// [/src/first/bin/first-output.d.ts]
@@ -788,7 +790,8 @@ sourceFile:../first_part3.ts
       "end": 407,
       "kind": "sourceMapUrl"
     }
-  ]
+  ],
+  "commonSourceDirectory": "/src/third/"
 }
 
 //// [/src/third/thirdjs/output/third-output.d.ts]