update test/unit/multiple_translation_units_test.cpp to cover all of the stan math library

Author: SteveBronder

make/tests

@@ -38,7 +38,7 @@ endif
 
 ##
 # Adding a test for multiple translation units. If this fails,
-# a new function is probably missing an inline
+# a public umbrella header likely exposes a new non-inline external definition.
 ##
 
 ifneq ($(OS),Windows_NT)

test/unit/multiple_translation_units1.cpp

@@ -1,3 +1,3 @@
-#include <stan/math.hpp>
+#include <test/unit/multiple_translation_units_includes.hpp>
 
 inline stan::math::var function1() { return 0; }

test/unit/multiple_translation_units2.cpp

@@ -1,3 +1,3 @@
-#include <stan/math.hpp>
+#include <test/unit/multiple_translation_units_includes.hpp>
 
 inline stan::math::var function2() { return 0; }

test/unit/multiple_translation_units_includes.hpp

@@ -0,0 +1,14 @@
+#ifndef TEST_UNIT_MULTIPLE_TRANSLATION_UNITS_INCLUDES_HPP
+#define TEST_UNIT_MULTIPLE_TRANSLATION_UNITS_INCLUDES_HPP
+
+// Keep this list aligned with the public Stan Math umbrella headers. Each
+// translation unit test source includes this header so linking catches ODR
+// violations from any externally linked header-defined function reachable from
+// the public entry points.
+#include <stan/math.hpp>
+#include <stan/math/fwd.hpp>
+#include <stan/math/mix.hpp>
+#include <stan/math/prim.hpp>
+#include <stan/math/rev.hpp>
+
+#endif

test/unit/multiple_translation_units_test.cpp

@@ -2,5 +2,5 @@
 
 TEST(multiple_translation_units, compile) {
   SUCCEED() << "this test compiling indicates that compiling the math library "
-            << "with multiple translation units is ok.";
+            << "public umbrella headers with multiple translation units is ok.";
 }