Index: clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
+++ clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
@@ -493,13 +493,11 @@
   }
 }
 
-static bool isBisonFile(ASTContext &C) {
+static bool fileContainsString(StringRef Substring, ASTContext &C) {
   const SourceManager &SM = C.getSourceManager();
   FileID FID = SM.getMainFileID();
   StringRef Buffer = SM.getBufferOrFake(FID).getBuffer();
-  if (Buffer.startswith("/* A Bison parser, made by"))
-    return true;
-  return false;
+  return Buffer.contains(Substring);
 }
 
 void AnalysisConsumer::runAnalysisOnTranslationUnit(ASTContext &C) {
@@ -552,8 +550,10 @@
   if (Diags.hasErrorOccurred() || Diags.hasFatalErrorOccurred())
     return;
 
-  if (isBisonFile(C)) {
+  if (fileContainsString("/* A Bison parser, made by", C)) {
     reportAnalyzerProgress("Skipping bison-generated file\n");
+  } else if (fileContainsString("/* A lexical scanner generated by flex", C)) {
+    reportAnalyzerProgress("Skipping flex-generated file\n");
   } else if (Opts->DisableAllCheckers) {
 
     // Don't analyze if the user explicitly asked for no checks to be performed
Index: clang/test/Analysis/flexignore.c
===================================================================
--- /dev/null
+++ clang/test/Analysis/flexignore.c
@@ -0,0 +1,10 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection -verify %s
+//
+// expected-no-diagnostics
+
+/* A lexical scanner generated by flex */
+
+void clang_analyzer_warnIfReached();
+void foo() {
+  clang_analyzer_warnIfReached(); // no-warning
+}
Index: clang/test/Analysis/yaccignore.c
===================================================================
--- clang/test/Analysis/yaccignore.c
+++ clang/test/Analysis/yaccignore.c
@@ -1,13 +1,10 @@
-/* A Bison parser, made by GNU Bison 1.875.  */
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection -verify %s
+//
+// expected-no-diagnostics
 
-// RUN: rm -rf %t.plist
-// RUN: %clang_analyze_cc1 -analyzer-checker=core -analyzer-output=plist -o %t.plist -verify %s
-// RUN: FileCheck --input-file=%t.plist %s
+/* A Bison parser, made by GNU Bison 1.875.  */
 
-// expected-no-diagnostics
-int foo() {
-  int *x = 0;
-  return *x; // no-warning
+void clang_analyzer_warnIfReached();
+void foo() {
+  clang_analyzer_warnIfReached(); // no-warning
 }
-
-// CHECK:   <key>diagnostics</key>