Index: include/clang/AST/PrettyPrinter.h
===================================================================
--- include/clang/AST/PrettyPrinter.h
+++ include/clang/AST/PrettyPrinter.h
@@ -38,21 +38,20 @@
 struct PrintingPolicy {
   /// Create a default printing policy for the specified language.
   PrintingPolicy(const LangOptions &LO)
-    : Indentation(2), SuppressSpecifiers(false),
-      SuppressTagKeyword(LO.CPlusPlus),
-      IncludeTagDefinition(false), SuppressScope(false),
-      SuppressUnwrittenScope(false), SuppressInitializers(false),
-      ConstantArraySizeAsWritten(false), AnonymousTagLocations(true),
-      SuppressStrongLifetime(false), SuppressLifetimeQualifiers(false),
-      SuppressTemplateArgsInCXXConstructors(false),
-      Bool(LO.Bool), Restrict(LO.C99),
-      Alignof(LO.CPlusPlus11), UnderscoreAlignof(LO.C11),
-      UseVoidForZeroParams(!LO.CPlusPlus),
-      TerseOutput(false), PolishForDeclaration(false),
-      Half(LO.Half), MSWChar(LO.MicrosoftExt && !LO.WChar),
-      IncludeNewlines(true), MSVCFormatting(false),
-      ConstantsAsWritten(false), SuppressImplicitBase(false),
-      FullyQualifiedName(false) { }
+      : Indentation(2), SuppressSpecifiers(false),
+        SuppressTagKeyword(LO.CPlusPlus), IncludeTagDefinition(false),
+        SuppressScope(false), SuppressUnwrittenScope(false),
+        SuppressInitializers(false), ConstantArraySizeAsWritten(false),
+        AnonymousTagLocations(true), SuppressStrongLifetime(false),
+        SuppressLifetimeQualifiers(false),
+        SuppressTemplateArgsInCXXConstructors(false), Bool(LO.Bool),
+        Restrict(LO.C99), Alignof(LO.CPlusPlus11), UnderscoreAlignof(LO.C11),
+        UseVoidForZeroParams(!LO.CPlusPlus), TerseOutput(false),
+        PolishForDeclaration(false), Half(LO.Half),
+        MSWChar(LO.MicrosoftExt && !LO.WChar), IncludeNewlines(true),
+        MSVCFormatting(false), ConstantsAsWritten(false),
+        SuppressImplicitBase(false), FullyQualifiedName(false),
+        RemapFilePaths(false) {}
 
   /// Adjust this printing policy for cases where it's known that we're
   /// printing C++ code (for instance, if AST dumping reaches a C++-only
@@ -225,8 +224,14 @@
   /// When true, print the fully qualified name of function declarations.
   /// This is the opposite of SuppressScope and thus overrules it.
   unsigned FullyQualifiedName : 1;
-};
 
+  /// Whether to apply -fdebug-prefix-map to any file paths.
+  unsigned RemapFilePaths : 1;
+
+  /// When RemapFilePaths is true, this function performs the action.
+  std::function<std::string(StringRef)> remapPath;
+};
+  
 } // end namespace clang
 
 #endif
Index: lib/AST/TypePrinter.cpp
===================================================================
--- lib/AST/TypePrinter.cpp
+++ lib/AST/TypePrinter.cpp
@@ -1157,9 +1157,13 @@
       PresumedLoc PLoc = D->getASTContext().getSourceManager().getPresumedLoc(
           D->getLocation());
       if (PLoc.isValid()) {
-        OS << " at " << PLoc.getFilename()
-           << ':' << PLoc.getLine()
-           << ':' << PLoc.getColumn();
+        OS << " at ";
+        StringRef File = PLoc.getFilename();
+        if (Policy.RemapFilePaths)
+          OS << Policy.remapPath(File);
+        else
+          OS << File;
+        OS << ':' << PLoc.getLine() << ':' << PLoc.getColumn();
       }
     }
 
Index: lib/CodeGen/CGDebugInfo.h
===================================================================
--- lib/CodeGen/CGDebugInfo.h
+++ lib/CodeGen/CGDebugInfo.h
@@ -341,6 +341,9 @@
 
   void finalize();
 
+  /// Remap a path using the -fdebug-prefix-map.
+  std::string remapDIPath(StringRef Path) const;
+
   /// Register VLA size expression debug node with the qualified type.
   void registerVLASizeExpression(QualType Ty, llvm::Metadata *SizeExpr) {
     SizeExprCache[Ty] = SizeExpr;
@@ -528,9 +531,6 @@
   /// Create new compile unit.
   void CreateCompileUnit();
 
-  /// Remap a given path with the current debug prefix map
-  std::string remapDIPath(StringRef) const;
-
   /// Compute the file checksum debug info for input file ID.
   Optional<llvm::DIFile::ChecksumKind>
   computeChecksum(FileID FID, SmallString<32> &Checksum) const;
Index: lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- lib/CodeGen/CGDebugInfo.cpp
+++ lib/CodeGen/CGDebugInfo.cpp
@@ -234,6 +234,11 @@
   if (CGM.getCodeGenOpts().EmitCodeView)
     PP.MSVCFormatting = true;
 
+  // Apply -fdebug-prefix-map.
+  if (!DebugPrefixMap.empty()) {
+    PP.RemapFilePaths = true;
+    PP.remapPath = [this](StringRef Path) { return remapDIPath(Path); };
+  }
   return PP;
 }
 
Index: test/CodeGenCXX/debug-prefix-map-lambda.cpp
===================================================================
--- /dev/null
+++ test/CodeGenCXX/debug-prefix-map-lambda.cpp
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -debug-info-kind=limited -triple %itanium_abi_triple \
+// RUN:   -fdebug-prefix-map=%S=/SOURCE_ROOT %s -emit-llvm -o - | FileCheck %s
+
+template <typename T> void b(T) {}
+void c() {
+  // CHECK: !DISubprogram(name: "b<(lambda at
+  // CHECK-SAME:          /SOURCE_ROOT/debug-prefix-map-lambda.cpp
+  // CHECK-SAME:          [[@LINE+1]]:{{[0-9]+}})>"
+  b([]{});
+}