Index: unittests/AST/ASTImporterFixtures.h
===================================================================
--- unittests/AST/ASTImporterFixtures.h
+++ unittests/AST/ASTImporterFixtures.h
@@ -42,6 +42,8 @@
 void createVirtualFileIfNeeded(ASTUnit *ToAST, StringRef FileName,
                                StringRef Code);
 
+void checkImportedSourceLocations(const Decl *FromD, const Decl *ToD);
+
 // Common base for the different families of ASTImporter tests that are
 // parameterized on the compiler options which may result a different AST. E.g.
 // -fms-compatibility or -fdelayed-template-parsing.
Index: unittests/AST/ASTImporterFixtures.cpp
===================================================================
--- unittests/AST/ASTImporterFixtures.cpp
+++ unittests/AST/ASTImporterFixtures.cpp
@@ -18,6 +18,8 @@
 #include "clang/Frontend/ASTUnit.h"
 #include "clang/Tooling/Tooling.h"
 
+#include <regex>
+
 namespace clang {
 namespace ast_matchers {
 
@@ -38,6 +40,82 @@
                                    llvm::MemoryBuffer::getMemBuffer(Code));
 }
 
+void checkImportedSourceLocations(const Decl *FromD, const Decl *ToD) {
+  // Check AST dump for matching source locations in From and To AST.
+  // The first line of the AST dump contains information about the root node and
+  // some of the SourceLocation info, but certainly not everything.
+  // Still it is worth to check these. The test can be extended to check the
+  // whole AST dump but for this to work the ordering of imported Decls must be
+  // the same which is not the case now.
+  // The AST dump additionally traverses the AST and can catch certain bugs like
+  // poorly or not implemented subtrees.
+
+  // Print debug information?
+  const bool Print = false;
+
+  SmallString<1024> ToPrinted;
+  SmallString<1024> FromPrinted;
+  llvm::raw_svector_ostream ToStream(ToPrinted);
+  llvm::raw_svector_ostream FromStream(FromPrinted);
+
+  ToD->dump(ToStream);
+  FromD->dump(FromStream);
+
+  // search for SourceLocation strings:
+  // <filename>:<line>:<col>
+  // or
+  // line:<line>:<col>
+  // or
+  // col:<col>
+  // or
+  // '<invalid sloc>'
+  // If a component (filename or line) is same as in the last location
+  // it is not printed.
+  // Filename component is grouped into sub-expression to make it extractable.
+  std::regex MatchSourceLoc(
+      "<invalid sloc>|((\\w|\\.)+):\\d+:\\d+|line:\\d+:\\d+|col:\\d+");
+
+  std::string ToString(ToStream.str());
+  std::string FromString(FromStream.str());
+  int ToEndl = ToString.find('\n');
+  if (ToEndl == std::string::npos)
+    ToEndl = ToString.size();
+  int FromEndl = FromString.find('\n');
+  if (FromEndl == std::string::npos)
+    FromEndl = FromString.size();
+  auto ToLoc = std::sregex_iterator(ToString.begin(), ToString.begin() + ToEndl,
+                                    MatchSourceLoc);
+  auto FromLoc = std::sregex_iterator(
+      FromString.begin(), FromString.begin() + FromEndl, MatchSourceLoc);
+  if (Print) {
+    llvm::errs() << ToString << "\n\n\n" << FromString << "\n";
+    llvm::errs() << "----\n";
+  }
+  if (ToLoc->size() > 1 && FromLoc->size() > 1 && (*ToLoc)[1] != (*FromLoc)[1])
+    // Different filenames in To and From.
+    // This should mean that a to-be-imported decl was mapped to an existing
+    // (these normally reside in different files) and the check is
+    // not applicable.
+    return;
+
+  bool SourceLocationMismatch = false;
+  while (ToLoc != std::sregex_iterator() && FromLoc != std::sregex_iterator()) {
+    if (Print)
+      llvm::errs() << ToLoc->str() << "|" << FromLoc->str() << "\n";
+    SourceLocationMismatch =
+        SourceLocationMismatch || (ToLoc->str() != FromLoc->str());
+    ++ToLoc;
+    ++FromLoc;
+  }
+  if (Print)
+    llvm::errs() << "----\n";
+
+  if (FromLoc != std::sregex_iterator() || ToLoc != std::sregex_iterator())
+    SourceLocationMismatch = true;
+
+  EXPECT_FALSE(SourceLocationMismatch);
+}
+
 ASTImporterTestBase::TU::TU(StringRef Code, StringRef FileName, ArgVector Args,
                             ImporterConstructor C)
     : Code(Code), FileName(FileName),
@@ -179,7 +257,10 @@
   lazyInitToAST(ToLang, "", OutputFileName);
   TU *FromTU = findFromTU(From);
   assert(LookupTablePtr);
-  return FromTU->import(*LookupTablePtr, ToAST.get(), From);
+  Decl *To = FromTU->import(*LookupTablePtr, ToAST.get(), From);
+  if (To)
+    checkImportedSourceLocations(From, To);
+  return To;
 }
 
 QualType ASTImporterTestBase::ImportType(QualType FromType, Decl *TUDecl,
Index: unittests/AST/ASTImporterTest.cpp
===================================================================
--- unittests/AST/ASTImporterTest.cpp
+++ unittests/AST/ASTImporterTest.cpp
@@ -49,9 +49,8 @@
       llvm::raw_svector_ostream ToNothing(ImportChecker);
       ToCtx.getTranslationUnitDecl()->print(ToNothing);
 
-      // This traverses the AST to catch certain bugs like poorly or not
-      // implemented subtrees.
-      (*Imported)->dump(ToNothing);
+      // Additional SourceLocation checks.
+      checkImportedSourceLocations(Node, *Imported);
     }
 
     return Imported;