SERVER-27211 de-duplicate symbol `isMongos`

A hidden global variable representing the "is Mongos process" state
can now be accessed and updated by the `is_mongos.h` interface.  All
tests defining their own versions (and test crutches) are replaced
with calls to global registration of the desired state of this variable.
The `mongos` main executable now sets this hidden global state as part
of its startup code.

2 files changed, 1 insertions, 6 deletions

diff --git a/src/mongo/db/sorter/SConscript b/src/mongo/db/sorter/SConscript
index 959f6cdb919..365c1a91f54 100644
--- a/src/mongo/db/sorter/SConscript
+++ b/src/mongo/db/sorter/SConscript
@@ -7,4 +7,5 @@ sorterEnv.CppUnitTest('sorter_test',
                        LIBDEPS=['$BUILD_DIR/mongo/db/service_context',
                                 '$BUILD_DIR/mongo/db/storage/wiredtiger/storage_wiredtiger_customization_hooks',
                                 '$BUILD_DIR/mongo/db/storage/storage_options',
+                                '$BUILD_DIR/mongo/s/is_mongos',
                                 '$BUILD_DIR/third_party/shim_snappy'])
diff --git a/src/mongo/db/sorter/sorter_test.cpp b/src/mongo/db/sorter/sorter_test.cpp
index 19171fb13ba..1bf02fdcbf3 100644
--- a/src/mongo/db/sorter/sorter_test.cpp
+++ b/src/mongo/db/sorter/sorter_test.cpp
@@ -52,12 +52,6 @@ using namespace mongo::sorter;
 using std::make_shared;
 using std::pair;
 
-// Stub to avoid including the server_options library
-// TODO: This should go away once we can do these checks at compile time
-bool isMongos() {
-    return false;
-}
-
 // Stub to avoid including the server environment library.
 MONGO_INITIALIZER(SetGlobalEnvironment)(InitializerContext* context) {
     setGlobalServiceContext(stdx::make_unique<ServiceContextNoop>());