diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -516,14 +516,14 @@
   // We have found a header, but it is private.
   if (Private) {
     Diags.Report(FilenameLoc, diag::warn_use_of_private_header_outside_module)
-        << Filename;
+        << File->getName();
     return;
   }
 
   // We have found a module, but we don't use it.
   if (NotUsed) {
     Diags.Report(FilenameLoc, diag::err_undeclared_use_of_module)
-        << RequestingModule->getTopLevelModule()->Name << Filename;
+        << RequestingModule->getTopLevelModule()->Name << File->getName();
     return;
   }
 
@@ -534,7 +534,7 @@
 
   if (RequestingModule && LangOpts.ModulesStrictDeclUse) {
     Diags.Report(FilenameLoc, diag::err_undeclared_use_of_module)
-        << RequestingModule->getTopLevelModule()->Name << Filename;
+        << RequestingModule->getTopLevelModule()->Name << File->getName();
   } else if (RequestingModule && RequestingModuleIsModuleInterface &&
              LangOpts.isCompilingModule()) {
     // Do not diagnose when we are not compiling a module.
diff --git a/clang/test/Modules/declare-use1.cpp b/clang/test/Modules/declare-use1.cpp
--- a/clang/test/Modules/declare-use1.cpp
+++ b/clang/test/Modules/declare-use1.cpp
@@ -3,7 +3,7 @@
 
 #include "g.h"
 #include "e.h"
-#include "f.h" // expected-error {{module XG does not depend on a module exporting 'f.h'}}
+#include "f.h" // expected-error-re {{module XG does not depend on a module exporting '{{.*}}{{/|\\}}f.h'}}
 #include "i.h"
 #include "sub.h"
 const int g2 = g1 + e + f + aux_i + sub;
diff --git a/clang/test/Modules/declare-use2.cpp b/clang/test/Modules/declare-use2.cpp
--- a/clang/test/Modules/declare-use2.cpp
+++ b/clang/test/Modules/declare-use2.cpp
@@ -3,5 +3,5 @@
 
 #include "h.h"
 #include "e.h"
-#include "f.h" // expected-error {{module XH does not depend on a module exporting 'f.h'}}
+#include "f.h" // expected-error-re {{module XH does not depend on a module exporting '{{.*}}{{/|\\}}f.h'}}
 const int h2 = h1+e+f;
diff --git a/clang/test/Modules/declare-use3.cpp b/clang/test/Modules/declare-use3.cpp
--- a/clang/test/Modules/declare-use3.cpp
+++ b/clang/test/Modules/declare-use3.cpp
@@ -1,4 +1,4 @@
 // RUN: rm -rf %t
 // RUN: %clang_cc1 -include "g.h" -include "e.h" -include "f.h" -include "i.h" -fimplicit-module-maps -fmodules-cache-path=%t -fmodules-decluse -fmodule-name=XG -I %S/Inputs/declare-use %s -verify
-// expected-error {{module XG does not depend on a module exporting 'f.h'}}
+// expected-error-re {{module XG does not depend on a module exporting '{{.*}}{{/|\\}}f.h'}}
 const int g2 = g1 + e + f + aux_i;
diff --git a/clang/test/Modules/header-attribs.cpp b/clang/test/Modules/header-attribs.cpp
--- a/clang/test/Modules/header-attribs.cpp
+++ b/clang/test/Modules/header-attribs.cpp
@@ -3,8 +3,8 @@
 // RUN: not %clang_cc1 -fmodules -I%S/Inputs/header-attribs -emit-module -x c++-module-map %S/Inputs/header-attribs/modular.modulemap -fmodules-cache-path=%t -fmodule-name=A 2>&1 | FileCheck %s --check-prefix BUILD-MODULAR
 
 #include "foo.h" // ok, stats match
-#include "bar.h" // expected-error {{does not depend on a module exporting 'bar.h'}}
-#include "baz.h" // expected-error {{does not depend on a module exporting 'baz.h'}}
+#include "bar.h" // expected-error-re {{does not depend on a module exporting '{{.*}}{{/|\\}}bar.h'}}
+#include "baz.h" // expected-error-re {{does not depend on a module exporting '{{.*}}{{/|\\}}baz.h'}}
 
 // FIXME: Explain why the 'bar.h' found on disk doesn't match the module map.
 // BUILD-MODULAR: error: header 'bar.h' not found
diff --git a/clang/test/Modules/strict-decluse-headers.cpp b/clang/test/Modules/strict-decluse-headers.cpp
--- a/clang/test/Modules/strict-decluse-headers.cpp
+++ b/clang/test/Modules/strict-decluse-headers.cpp
@@ -14,4 +14,4 @@
 // Don't crash on this: (FIXME: we should produce an error that the specified file is not part of the specified module)
 // RUN: %clang_cc1 -fsyntax-only -fmodules -fmodule-map-file=%t/map -I%t -fmodules-strict-decluse -fmodule-name=X -x c++ %t/foo.h
 //
-// CHECK: module X does not depend on a module exporting 'foo.h'
+// CHECK: module X does not depend on a module exporting '{{.*}}{{/|\\}}foo.h'
diff --git a/clang/test/Modules/strict-decluse.cpp b/clang/test/Modules/strict-decluse.cpp
--- a/clang/test/Modules/strict-decluse.cpp
+++ b/clang/test/Modules/strict-decluse.cpp
@@ -3,7 +3,7 @@
 
 #include "g.h"
 #include "e.h"
-#include "f.h" // expected-error {{module XG does not depend on a module exporting 'f.h'}}
-#include "i.h" // expected-error {{module XG does not depend on a module exporting 'i.h'}}
+#include "f.h" // expected-error-re {{module XG does not depend on a module exporting '{{.*}}{{/|\\}}f.h'}}
+#include "i.h" // expected-error-re {{module XG does not depend on a module exporting '{{.*}}{{/|\\}}i.h'}}
 
 const int g2 = g1 + e + f + aux_i;
diff --git a/clang/test/Modules/textual-headers.cpp b/clang/test/Modules/textual-headers.cpp
--- a/clang/test/Modules/textual-headers.cpp
+++ b/clang/test/Modules/textual-headers.cpp
@@ -6,13 +6,13 @@
 #include "k.h"
 
 #define GIMME_AN_L
-#include "l.h" // expected-error {{module XG does not depend on a module exporting 'l.h'}}
+#include "l.h" // expected-error-re {{module XG does not depend on a module exporting '{{.*}}{{/|\\}}l.h'}}
 
-#include "m2.h" // expected-error {{module XG does not depend on a module exporting 'm2.h'}}
+#include "m2.h" // expected-error-re {{module XG does not depend on a module exporting '{{.*}}{{/|\\}}m2.h'}}
 const int use_m = m; // expected-error {{undeclared identifier}}
 
 #define GIMME_AN_M
-#include "m.h" // expected-error {{use of private header from outside its module: 'm.h'}}
+#include "m.h" // expected-error-re {{use of private header from outside its module: '{{.*}}{{/|\\}}m.h'}}
 const int use_m_2 = m;
 
 const int g = k + l;