Index: clang/include/clang/Lex/Preprocessor.h
===================================================================
--- clang/include/clang/Lex/Preprocessor.h
+++ clang/include/clang/Lex/Preprocessor.h
@@ -1718,6 +1718,9 @@
   /// Lex the next token for this preprocessor.
   void Lex(Token &Result);
 
+  /// Lex all tokens for this preprocessor until end of file.
+  std::vector<Token> LexAll();
+
   /// Lex a token, forming a header-name token if possible.
   bool LexHeaderName(Token &Result, bool AllowMacroExpansion = true);
 
Index: clang/lib/Lex/Preprocessor.cpp
===================================================================
--- clang/lib/Lex/Preprocessor.cpp
+++ clang/lib/Lex/Preprocessor.cpp
@@ -995,6 +995,18 @@
   }
 }
 
+std::vector<Token> Preprocessor::LexAll() {
+  std::vector<Token> toks;
+  while (1) {
+    Token tok;
+    Lex(tok);
+    if (tok.is(tok::eof))
+      break;
+    toks.push_back(tok);
+  }
+  return toks;
+}
+
 /// Lex a header-name token (including one formed from header-name-tokens if
 /// \p AllowConcatenation is \c true).
 ///
Index: clang/unittests/Analysis/MacroExpansionContextTest.cpp
===================================================================
--- clang/unittests/Analysis/MacroExpansionContextTest.cpp
+++ clang/unittests/Analysis/MacroExpansionContextTest.cpp
@@ -73,12 +73,7 @@
     // Lex source text.
     PP.EnterMainSourceFile();
 
-    while (true) {
-      Token Tok;
-      PP.Lex(Tok);
-      if (Tok.is(tok::eof))
-        break;
-    }
+    (void)PP.LexAll();
 
     // Callbacks have been executed at this point.
     return Ctx;
Index: clang/unittests/Basic/SourceManagerTest.cpp
===================================================================
--- clang/unittests/Basic/SourceManagerTest.cpp
+++ clang/unittests/Basic/SourceManagerTest.cpp
@@ -137,14 +137,7 @@
   PP.Initialize(*Target);
   PP.EnterMainSourceFile();
 
-  std::vector<Token> toks;
-  while (1) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-    toks.push_back(tok);
-  }
+  std::vector<Token> toks = PP.LexAll();
 
   // Make sure we got the tokens that we expected.
   ASSERT_EQ(3U, toks.size());
@@ -194,14 +187,7 @@
   PP.EnterMainSourceFile();
   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);
-  }
+  std::vector<Token> toks = PP.LexAll();
 
   // Make sure we got the tokens that we expected.
   ASSERT_EQ(4U, toks.size()) << "a >> b c";
@@ -451,14 +437,7 @@
   PP.Initialize(*Target);
   PP.EnterMainSourceFile();
 
-  std::vector<Token> toks;
-  while (1) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-    toks.push_back(tok);
-  }
+  std::vector<Token> toks = PP.LexAll();
 
   // Make sure we got the tokens that we expected.
   ASSERT_EQ(4U, toks.size());
@@ -573,14 +552,7 @@
 
   PP.EnterMainSourceFile();
 
-  std::vector<Token> toks;
-  while (1) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-    toks.push_back(tok);
-  }
+  std::vector<Token> toks = PP.LexAll();
 
   // Make sure we got the tokens that we expected.
   ASSERT_EQ(0U, toks.size());
Index: clang/unittests/Lex/LexerTest.cpp
===================================================================
--- clang/unittests/Lex/LexerTest.cpp
+++ clang/unittests/Lex/LexerTest.cpp
@@ -71,14 +71,7 @@
     TrivialModuleLoader ModLoader;
     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);
-    }
+    std::vector<Token> toks = PP->LexAll();
 
     return toks;
   }
@@ -626,12 +619,7 @@
 TEST_F(LexerTest, CreatedFIDCountForPredefinedBuffer) {
   TrivialModuleLoader ModLoader;
   auto PP = CreatePP("", ModLoader);
-  while (1) {
-    Token tok;
-    PP->Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-  }
+  (void)PP->LexAll();
   EXPECT_EQ(SourceMgr.getNumCreatedFIDsForFileID(PP->getPredefinesFileID()),
             1U);
 }
Index: clang/unittests/Lex/ModuleDeclStateTest.cpp
===================================================================
--- clang/unittests/Lex/ModuleDeclStateTest.cpp
+++ clang/unittests/Lex/ModuleDeclStateTest.cpp
@@ -90,12 +90,7 @@
     PP.addPPCallbacks(std::move(C));
     PP.EnterMainSourceFile();
 
-    while (1) {
-      Token tok;
-      PP.Lex(tok);
-      if (tok.is(tok::eof))
-        break;
-    }
+    (void)PP.LexAll();
   }
 
   FileSystemOptions FileMgrOpts;
Index: clang/unittests/Lex/PPCallbacksTest.cpp
===================================================================
--- clang/unittests/Lex/PPCallbacksTest.cpp
+++ clang/unittests/Lex/PPCallbacksTest.cpp
@@ -229,13 +229,7 @@
 
     // Lex source text.
     PP.EnterMainSourceFile();
-
-    while (true) {
-      Token Tok;
-      PP.Lex(Tok);
-      if (Tok.is(tok::eof))
-        break;
-    }
+    (void)PP.LexAll();
 
     // Callbacks have been executed at this point -- return filename range.
     return Callbacks;
@@ -259,13 +253,7 @@
 
     // Lex source text.
     PP.EnterMainSourceFile();
-
-    while (true) {
-      Token Tok;
-      PP.Lex(Tok);
-      if (Tok.is(tok::eof))
-        break;
-    }
+    (void)PP.LexAll();
 
     return Callbacks->Results;
   }
@@ -290,12 +278,7 @@
 
     // Lex source text.
     PP.EnterMainSourceFile();
-    while (true) {
-      Token Tok;
-      PP.Lex(Tok);
-      if (Tok.is(tok::eof))
-        break;
-    }
+    (void)PP.LexAll();
 
     return Callbacks->Marks;
   }
@@ -334,12 +317,7 @@
 
     // Lex source text.
     PP.EnterMainSourceFile();
-    while (true) {
-      Token Tok;
-      PP.Lex(Tok);
-      if (Tok.is(tok::eof))
-        break;
-    }
+    (void)PP.LexAll();
 
     PragmaOpenCLExtensionCallbacks::CallbackParameters RetVal = {
       Callbacks->Name,
@@ -477,12 +455,7 @@
 
   // Lex source text.
   PP.EnterMainSourceFile();
-  while (true) {
-    Token Tok;
-    PP.Lex(Tok);
-    if (Tok.is(tok::eof))
-      break;
-  }
+  (void)PP.LexAll();
 
   ASSERT_EQ(1u, Callbacks->NumCalls);
   ASSERT_EQ(0u, DiagConsumer->getNumErrors());
Index: clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
===================================================================
--- clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
+++ clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
@@ -86,14 +86,7 @@
   PP.addPPCallbacks(std::unique_ptr<PPCallbacks>(PPRec));
   PP.EnterMainSourceFile();
 
-  std::vector<Token> toks;
-  while (1) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-    toks.push_back(tok);
-  }
+  std::vector<Token> toks = PP.LexAll();
 
   // Make sure we got the tokens that we expected.
   ASSERT_EQ(10U, toks.size());
Index: clang/unittests/Lex/PPDependencyDirectivesTest.cpp
===================================================================
--- clang/unittests/Lex/PPDependencyDirectivesTest.cpp
+++ clang/unittests/Lex/PPDependencyDirectivesTest.cpp
@@ -133,12 +133,7 @@
   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;
-  }
+  (void)PP.LexAll();
 
   SmallVector<StringRef> ExpectedIncludes{
       "main.c", "./head1.h", "./head2.h", "./head2.h", "./head3.h", "./head3.h",
Index: clang/unittests/Lex/PPMemoryAllocationsTest.cpp
===================================================================
--- clang/unittests/Lex/PPMemoryAllocationsTest.cpp
+++ clang/unittests/Lex/PPMemoryAllocationsTest.cpp
@@ -75,12 +75,7 @@
   PP.Initialize(*Target);
   PP.EnterMainSourceFile();
 
-  while (1) {
-    Token tok;
-    PP.Lex(tok);
-    if (tok.is(tok::eof))
-      break;
-  }
+  (void)PP.LexAll();
 
   size_t NumAllocated = PP.getPreprocessorAllocator().getBytesAllocated();
   float BytesPerDefine = float(NumAllocated) / float(NumMacros);