Index: lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
===================================================================
--- lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
+++ lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
@@ -43,6 +43,7 @@
 #include <memory>
 #include <queue>
 #include <utility>
+#include <string.h>
 
 using namespace clang;
 using namespace ento;
@@ -508,7 +509,23 @@
   }
 }
 
+static bool isBisonFile(ASTContext &C) {
+  const SourceManager &SM = C.getSourceManager();
+  FileID FID = SM.getMainFileID();
+  llvm::MemoryBuffer *Buffer = SM.getBuffer(FID);
+  const char *Start = Buffer->getBufferStart();
+  if (strncmp(Start, "/* A Bison parser, made by", 26) == 0)
+    return true;
+  return false;
+}
+
 void AnalysisConsumer::HandleTranslationUnit(ASTContext &C) {
+  if (isBisonFile(C)) {
+    if (Opts->AnalyzerDisplayProgress)
+      llvm::errs() << "Skipping bison-generated file\n";
+    return;
+  }
+
   // Don't run the actions if an error has occurred with parsing the file.
   DiagnosticsEngine &Diags = PP.getDiagnostics();
   if (Diags.hasErrorOccurred() || Diags.hasFatalErrorOccurred())
Index: test/Analysis/yaccignore.c
===================================================================
--- /dev/null
+++ test/Analysis/yaccignore.c
@@ -0,0 +1,9 @@
+/* A Bison parser, made by GNU Bison 1.875.  */
+
+// RUN: %clang_analyze_cc1 -analyzer-checker=core -verify %s
+
+// expected-no-diagnostics
+int foo() {
+  int *x = 0;
+  return *x; // no-warning
+}