Index: clang/include/clang/StaticAnalyzer/Core/AnalyzerOptions.def
===================================================================
--- clang/include/clang/StaticAnalyzer/Core/AnalyzerOptions.def
+++ clang/include/clang/StaticAnalyzer/Core/AnalyzerOptions.def
@@ -310,6 +310,10 @@
                 "Emit fix-it hints as remarks for testing purposes",
                 false)
 
+ANALYZER_OPTION(bool, ShouldReportInSystemHeader, "report-in-system-header",
+                "Emit a bug report even if it is located in a system header.",
+                true)
+
 //===----------------------------------------------------------------------===//
 // Unsigned analyzer options.
 //===----------------------------------------------------------------------===//
Index: clang/lib/StaticAnalyzer/Core/BugReporter.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/BugReporter.cpp
+++ clang/lib/StaticAnalyzer/Core/BugReporter.cpp
@@ -2827,6 +2827,12 @@
   if (!ValidSourceLoc)
     return;
 
+  // The goal of system headers is that no diagnostic report is emitted in
+  // those.
+  if (!getAnalyzerOptions().ShouldReportInSystemHeader &&
+      R->getLocation().asLocation().isInSystemHeader())
+    return;
+
   // Compute the bug report's hash to determine its equivalence class.
   llvm::FoldingSetNodeID ID;
   R->Profile(ID);
Index: clang/test/Analysis/analyzer-config.c
===================================================================
--- clang/test/Analysis/analyzer-config.c
+++ clang/test/Analysis/analyzer-config.c
@@ -87,6 +87,7 @@
 // CHECK-NEXT: prune-paths = true
 // CHECK-NEXT: region-store-small-struct-limit = 2
 // CHECK-NEXT: report-in-main-source-file = false
+// CHECK-NEXT: report-in-system-header = true
 // CHECK-NEXT: serialize-stats = false
 // CHECK-NEXT: silence-checkers = ""
 // CHECK-NEXT: stable-report-filename = false
@@ -99,4 +100,4 @@
 // CHECK-NEXT: unroll-loops = false
 // CHECK-NEXT: widen-loops = false
 // CHECK-NEXT: [stats]
-// CHECK-NEXT: num-entries = 96
+// CHECK-NEXT: num-entries = 97
Index: clang/test/Analysis/system-header.c
===================================================================
--- /dev/null
+++ clang/test/Analysis/system-header.c
@@ -0,0 +1,11 @@
+// RUN: %clang_analyze_cc1 -analyzer-opt-analyze-headers -analyzer-checker=security.FloatLoopCounter -analyzer-config report-in-system-header=false -isystem %S/system-include -verify %s
+
+#include <system-header.h>
+
+void normalFunction()
+{
+  for (float f = 0; f < 10; f += 1) // expected-warning {{Variable 'f' with floating point type 'float' should not be used as a loop counter}}
+    ;
+
+  systemFunction();
+}
Index: clang/test/Analysis/system-include/system-header.h
===================================================================
--- /dev/null
+++ clang/test/Analysis/system-include/system-header.h
@@ -0,0 +1,5 @@
+void systemFunction()
+{
+  for (float f = 0; f < 10; f += 1)
+    ;
+}