diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
index e88164f196c1f..a8d2599d94ebc 100644
--- a/clang/include/clang/Lex/Preprocessor.h
+++ b/clang/include/clang/Lex/Preprocessor.h
@@ -1722,6 +1722,9 @@ class Preprocessor {
   /// Lex the next token for this preprocessor.
   void Lex(Token &Result);
 
+  /// Lex all tokens for this preprocessor until (and excluding) end of file.
+  void LexTokensUntilEOF(std::vector<Token> *Tokens = nullptr);
+
   /// Lex a token, forming a header-name token if possible.
   bool LexHeaderName(Token &Result, bool AllowMacroExpansion = true);
 
diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index 73c37bc5161c4..b82dd1fe49c70 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -998,6 +998,17 @@ void Preprocessor::Lex(Token &Result) {
   }
 }
 
+void Preprocessor::LexTokensUntilEOF(std::vector<Token> *Tokens) {
+  while (1) {
+    Token Tok;
+    Lex(Tok);
+    if (Tok.isOneOf(tok::unknown, tok::eof, tok::eod))
+      break;
+    if (Tokens != nullptr)
+      Tokens->push_back(Tok);
+  }
+}
+
 /// Lex a header-name token (including one formed from header-name-tokens if
 /// \p AllowConcatenation is \c true).
 ///
diff --git a/clang/unittests/Analysis/MacroExpansionContextTest.cpp b/clang/unittests/Analysis/MacroExpansionContextTest.cpp
index 5c694c836a488..54b209e7b28c1 100644
--- a/clang/unittests/Analysis/MacroExpansionContextTest.cpp
+++ b/clang/unittests/Analysis/MacroExpansionContextTest.cpp
@@ -73,12 +73,7 @@ class MacroExpansionContextTest : public ::testing::Test {
     // Lex source text.
     PP.EnterMainSourceFile();
 
-    while (true) {
-      Token Tok;
-      PP.Lex(Tok);
-      if (Tok.is(tok::eof))
-        break;
-    }
+    PP.LexTokensUntilEOF();
 
     // Callbacks have been executed at this point.
     return Ctx;
diff --git a/clang/unittests/Basic/SourceManagerTest.cpp b/clang/unittests/Basic/SourceManagerTest.cpp
index f451e43bb53d7..cd2bd12106b0e 100644
--- a/clang/unittests/Basic/SourceManagerTest.cpp
+++ b/clang/unittests/Basic/SourceManagerTest.cpp
@@ -138,13 +138,7 @@ TEST_F(SourceManagerTest, isBeforeInTranslationUnit) {
   PP.EnterMainSourceFile();
 
   std::vector<Token> toks;
-  while (1) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-    toks.push_back(tok);
-  }
+  PP.LexTokensUntilEOF(&toks);
 
   // Make sure we got the tokens that we expected.
   ASSERT_EQ(3U, toks.size());
@@ -195,13 +189,7 @@ TEST_F(SourceManagerTest, isBeforeInTranslationUnitWithTokenSplit) {
   llvm::SmallString<8> Scratch;
 
   std::vector<Token> toks;
-  while (1) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-    toks.push_back(tok);
-  }
+  PP.LexTokensUntilEOF(&toks);
 
   // Make sure we got the tokens that we expected.
   ASSERT_EQ(4U, toks.size()) << "a >> b c";
@@ -452,13 +440,7 @@ TEST_F(SourceManagerTest, getMacroArgExpandedLocation) {
   PP.EnterMainSourceFile();
 
   std::vector<Token> toks;
-  while (1) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-    toks.push_back(tok);
-  }
+  PP.LexTokensUntilEOF(&toks);
 
   // Make sure we got the tokens that we expected.
   ASSERT_EQ(4U, toks.size());
@@ -574,13 +556,7 @@ TEST_F(SourceManagerTest, isBeforeInTranslationUnitWithMacroInInclude) {
   PP.EnterMainSourceFile();
 
   std::vector<Token> toks;
-  while (1) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-    toks.push_back(tok);
-  }
+  PP.LexTokensUntilEOF(&toks);
 
   // Make sure we got the tokens that we expected.
   ASSERT_EQ(0U, toks.size());
diff --git a/clang/unittests/Lex/LexerTest.cpp b/clang/unittests/Lex/LexerTest.cpp
index 8932265674a59..47aa2c131a304 100644
--- a/clang/unittests/Lex/LexerTest.cpp
+++ b/clang/unittests/Lex/LexerTest.cpp
@@ -74,13 +74,7 @@ class LexerTest : public ::testing::Test {
     PP = CreatePP(Source, ModLoader);
 
     std::vector<Token> toks;
-    while (1) {
-      Token tok;
-      PP->Lex(tok);
-      if (tok.is(tok::eof))
-        break;
-      toks.push_back(tok);
-    }
+    PP->LexTokensUntilEOF(&toks);
 
     return toks;
   }
@@ -628,12 +622,7 @@ TEST_F(LexerTest, FindNextToken) {
 TEST_F(LexerTest, CreatedFIDCountForPredefinedBuffer) {
   TrivialModuleLoader ModLoader;
   auto PP = CreatePP("", ModLoader);
-  while (1) {
-    Token tok;
-    PP->Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-  }
+  PP->LexTokensUntilEOF();
   EXPECT_EQ(SourceMgr.getNumCreatedFIDsForFileID(PP->getPredefinesFileID()),
             1U);
 }
diff --git a/clang/unittests/Lex/ModuleDeclStateTest.cpp b/clang/unittests/Lex/ModuleDeclStateTest.cpp
index ed694384da57c..15306ba22bf67 100644
--- a/clang/unittests/Lex/ModuleDeclStateTest.cpp
+++ b/clang/unittests/Lex/ModuleDeclStateTest.cpp
@@ -90,12 +90,7 @@ class ModuleDeclStateTest : public ::testing::Test {
     PP.addPPCallbacks(std::move(C));
     PP.EnterMainSourceFile();
 
-    while (1) {
-      Token tok;
-      PP.Lex(tok);
-      if (tok.is(tok::eof))
-        break;
-    }
+    PP.LexTokensUntilEOF();
   }
 
   FileSystemOptions FileMgrOpts;
diff --git a/clang/unittests/Lex/PPCallbacksTest.cpp b/clang/unittests/Lex/PPCallbacksTest.cpp
index b2be40ef3812e..e0a27b5111821 100644
--- a/clang/unittests/Lex/PPCallbacksTest.cpp
+++ b/clang/unittests/Lex/PPCallbacksTest.cpp
@@ -229,13 +229,7 @@ class PPCallbacksTest : public ::testing::Test {
 
     // Lex source text.
     PP.EnterMainSourceFile();
-
-    while (true) {
-      Token Tok;
-      PP.Lex(Tok);
-      if (Tok.is(tok::eof))
-        break;
-    }
+    PP.LexTokensUntilEOF();
 
     // Callbacks have been executed at this point -- return filename range.
     return Callbacks;
@@ -259,13 +253,7 @@ class PPCallbacksTest : public ::testing::Test {
 
     // Lex source text.
     PP.EnterMainSourceFile();
-
-    while (true) {
-      Token Tok;
-      PP.Lex(Tok);
-      if (Tok.is(tok::eof))
-        break;
-    }
+    PP.LexTokensUntilEOF();
 
     return Callbacks->Results;
   }
@@ -290,12 +278,7 @@ class PPCallbacksTest : public ::testing::Test {
 
     // Lex source text.
     PP.EnterMainSourceFile();
-    while (true) {
-      Token Tok;
-      PP.Lex(Tok);
-      if (Tok.is(tok::eof))
-        break;
-    }
+    PP.LexTokensUntilEOF();
 
     return Callbacks->Marks;
   }
@@ -334,12 +317,7 @@ class PPCallbacksTest : public ::testing::Test {
 
     // Lex source text.
     PP.EnterMainSourceFile();
-    while (true) {
-      Token Tok;
-      PP.Lex(Tok);
-      if (Tok.is(tok::eof))
-        break;
-    }
+    PP.LexTokensUntilEOF();
 
     PragmaOpenCLExtensionCallbacks::CallbackParameters RetVal = {
       Callbacks->Name,
@@ -477,12 +455,7 @@ TEST_F(PPCallbacksTest, FileNotFoundSkipped) {
 
   // Lex source text.
   PP.EnterMainSourceFile();
-  while (true) {
-    Token Tok;
-    PP.Lex(Tok);
-    if (Tok.is(tok::eof))
-      break;
-  }
+  PP.LexTokensUntilEOF();
 
   ASSERT_EQ(1u, Callbacks->NumCalls);
   ASSERT_EQ(0u, DiagConsumer->getNumErrors());
diff --git a/clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp b/clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
index ba75639578651..84c4cc3a1b2dc 100644
--- a/clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
+++ b/clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
@@ -87,13 +87,7 @@ TEST_F(PPConditionalDirectiveRecordTest, PPRecAPI) {
   PP.EnterMainSourceFile();
 
   std::vector<Token> toks;
-  while (1) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-    toks.push_back(tok);
-  }
+  PP.LexTokensUntilEOF(&toks);
 
   // Make sure we got the tokens that we expected.
   ASSERT_EQ(10U, toks.size());
diff --git a/clang/unittests/Lex/PPDependencyDirectivesTest.cpp b/clang/unittests/Lex/PPDependencyDirectivesTest.cpp
index 4685021b6ecdb..6ff87f720a559 100644
--- a/clang/unittests/Lex/PPDependencyDirectivesTest.cpp
+++ b/clang/unittests/Lex/PPDependencyDirectivesTest.cpp
@@ -133,12 +133,7 @@ TEST_F(PPDependencyDirectivesTest, MacroGuard) {
   SmallVector<StringRef> IncludedFiles;
   PP.addPPCallbacks(std::make_unique<IncludeCollector>(PP, IncludedFiles));
   PP.EnterMainSourceFile();
-  while (true) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-  }
+  PP.LexTokensUntilEOF();
 
   SmallVector<std::string> IncludedFilesSlash;
   for (StringRef IncludedFile : IncludedFiles)
diff --git a/clang/unittests/Lex/PPMemoryAllocationsTest.cpp b/clang/unittests/Lex/PPMemoryAllocationsTest.cpp
index 894d94e149a9f..f7fb097b1f7fa 100644
--- a/clang/unittests/Lex/PPMemoryAllocationsTest.cpp
+++ b/clang/unittests/Lex/PPMemoryAllocationsTest.cpp
@@ -75,12 +75,7 @@ TEST_F(PPMemoryAllocationsTest, PPMacroDefinesAllocations) {
   PP.Initialize(*Target);
   PP.EnterMainSourceFile();
 
-  while (1) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-  }
+  PP.LexTokensUntilEOF();
 
   size_t NumAllocated = PP.getPreprocessorAllocator().getBytesAllocated();
   float BytesPerDefine = float(NumAllocated) / float(NumMacros);