Index: clang/include/clang/StaticAnalyzer/Checkers/Checkers.td
===================================================================
--- clang/include/clang/StaticAnalyzer/Checkers/Checkers.td
+++ clang/include/clang/StaticAnalyzer/Checkers/Checkers.td
@@ -365,18 +365,6 @@
 
 } // end "apiModeling"
 
-let ParentPackage = APIModelingAlpha in {
-
-def StdCLibraryFunctionArgsChecker : Checker<"StdCLibraryFunctionArgs">,
-  HelpText<"Check constraints of arguments of C standard library functions, "
-           "such as whether the parameter of isalpha is in the range [0, 255] "
-           "or is EOF.">,
-  Dependencies<[StdCLibraryFunctionsChecker]>,
-  WeakDependencies<[NonNullParamChecker]>,
-  Documentation<NotDocumented>;
-
-} // end "alpha.apiModeling"
-
 //===----------------------------------------------------------------------===//
 // Evaluate "builtin" functions.
 //===----------------------------------------------------------------------===//
@@ -535,6 +523,14 @@
   HelpText<"Check for calls to blocking functions inside a critical section">,
   Documentation<HasAlphaDocumentation>;
 
+def StdCLibraryFunctionArgsChecker : Checker<"StdCLibraryFunctionArgs">,
+  HelpText<"Check constraints of arguments of C standard library functions, "
+           "such as whether the parameter of isalpha is in the range [0, 255] "
+           "or is EOF.">,
+  Dependencies<[StdCLibraryFunctionsChecker]>,
+  WeakDependencies<[NonNullParamChecker]>,
+  Documentation<NotDocumented>;
+
 } // end "alpha.unix"
 
 //===----------------------------------------------------------------------===//
Index: clang/lib/StaticAnalyzer/Core/BugReporter.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/BugReporter.cpp
+++ clang/lib/StaticAnalyzer/Core/BugReporter.cpp
@@ -2107,7 +2107,7 @@
 // Methods for BugReport and subclasses.
 //===----------------------------------------------------------------------===//
 
-static bool isDependency(const CheckerRegistry &Registry,
+LLVM_ATTRIBUTE_USED static bool isDependency(const CheckerRegistry &Registry,
                          StringRef CheckerName) {
   for (const std::pair<StringRef, StringRef> &Pair : Registry.Dependencies) {
     if (Pair.second == CheckerName)
@@ -2116,6 +2116,17 @@
   return false;
 }
 
+LLVM_ATTRIBUTE_USED static bool isHidden(const CheckerRegistry &Registry,
+                         StringRef CheckerName) {
+  for (const CheckerRegistry::CheckerInfo &Checker : Registry.Checkers) {
+    if (Checker.FullName == CheckerName)
+      return Checker.IsHidden;
+  }
+  llvm_unreachable(
+      "Checker name not found in CheckerRegistry -- did you retrieve it "
+      "correctly from CheckerManager::getCurrentCheckerName?");
+}
+
 PathSensitiveBugReport::PathSensitiveBugReport(
     const BugType &bt, StringRef shortDesc, StringRef desc,
     const ExplodedNode *errorNode, PathDiagnosticLocation LocationToUnique,
@@ -2131,6 +2142,16 @@
          "Some checkers depend on this one! We don't allow dependency "
          "checkers to emit warnings, because checkers should depend on "
          "*modeling*, not *diagnostics*.");
+
+  assert(
+      bt.getCheckerName().startswith("debug") ||
+      !isHidden(ErrorNode->getState()
+                    ->getAnalysisManager()
+                    .getCheckerManager()
+                    ->getCheckerRegistry(),
+                bt.getCheckerName()) &&
+          "Hidden checkers musn't emit diagnostics as they are by definition "
+          "non-user facing!");
 }
 
 void PathSensitiveBugReport::addVisitor(
Index: clang/test/Analysis/std-c-library-functions-arg-constraints.c
===================================================================
--- clang/test/Analysis/std-c-library-functions-arg-constraints.c
+++ clang/test/Analysis/std-c-library-functions-arg-constraints.c
@@ -2,7 +2,7 @@
 // RUN: %clang_analyze_cc1 %s \
 // RUN:   -analyzer-checker=core \
 // RUN:   -analyzer-checker=apiModeling.StdCLibraryFunctions \
-// RUN:   -analyzer-checker=alpha.apiModeling.StdCLibraryFunctionArgs \
+// RUN:   -analyzer-checker=alpha.unix.StdCLibraryFunctionArgs \
 // RUN:   -analyzer-checker=debug.StdCLibraryFunctionsTester \
 // RUN:   -analyzer-checker=debug.ExprInspection \
 // RUN:   -triple x86_64-unknown-linux-gnu \
@@ -12,7 +12,7 @@
 // RUN: %clang_analyze_cc1 %s \
 // RUN:   -analyzer-checker=core \
 // RUN:   -analyzer-checker=apiModeling.StdCLibraryFunctions \
-// RUN:   -analyzer-checker=alpha.apiModeling.StdCLibraryFunctionArgs \
+// RUN:   -analyzer-checker=alpha.unix.StdCLibraryFunctionArgs \
 // RUN:   -analyzer-checker=debug.StdCLibraryFunctionsTester \
 // RUN:   -analyzer-checker=debug.ExprInspection \
 // RUN:   -triple x86_64-unknown-linux-gnu \
Index: clang/test/Analysis/std-c-library-functions-arg-constraints.cpp
===================================================================
--- clang/test/Analysis/std-c-library-functions-arg-constraints.cpp
+++ clang/test/Analysis/std-c-library-functions-arg-constraints.cpp
@@ -1,7 +1,7 @@
 // RUN: %clang_analyze_cc1 %s \
 // RUN:   -analyzer-checker=core \
 // RUN:   -analyzer-checker=apiModeling.StdCLibraryFunctions \
-// RUN:   -analyzer-checker=alpha.apiModeling.StdCLibraryFunctionArgs \
+// RUN:   -analyzer-checker=alpha.unix.StdCLibraryFunctionArgs \
 // RUN:   -analyzer-checker=debug.StdCLibraryFunctionsTester \
 // RUN:   -analyzer-checker=debug.ExprInspection \
 // RUN:   -analyzer-config eagerly-assume=false \
Index: clang/test/Analysis/weak-dependencies.c
===================================================================
--- clang/test/Analysis/weak-dependencies.c
+++ clang/test/Analysis/weak-dependencies.c
@@ -1,5 +1,5 @@
 // RUN: %clang_analyze_cc1 %s -verify \
-// RUN:   -analyzer-checker=alpha.apiModeling.StdCLibraryFunctionArgs \
+// RUN:   -analyzer-checker=alpha.unix.StdCLibraryFunctionArgs \
 // RUN:   -analyzer-checker=core
 
 typedef __typeof(sizeof(int)) size_t;