1 files changed, 68 insertions, 0 deletions
diff --git a/ext/misc/noop.c b/ext/misc/noop.c
new file mode 100644
index 0000000..d3a5867
--- /dev/null
+++ b/ext/misc/noop.c
@@ -0,0 +1,68 @@
+/*
+** 2020-01-08
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This SQLite extension implements a noop() function used for testing.
+**
+** Variants:
+**
+**    noop(X)           The default.  Deterministic.
+**    noop_i(X)         Deterministic and innocuous.
+**    noop_do(X)        Deterministic and direct-only.
+**    noop_nd(X)        Non-deterministic.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <assert.h>
+#include <string.h>
+
+/*
+** Implementation of the noop() function.
+**
+** The function returns its argument, unchanged.
+*/
+static void noopfunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  assert( argc==1 );
+  sqlite3_result_value(context, argv[0]);
+}
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_noop_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  rc = sqlite3_create_function(db, "noop", 1,
+                     SQLITE_UTF8 | SQLITE_DETERMINISTIC,
+                     0, noopfunc, 0, 0);
+  if( rc ) return rc;
+  rc = sqlite3_create_function(db, "noop_i", 1,
+                     SQLITE_UTF8 | SQLITE_DETERMINISTIC | SQLITE_INNOCUOUS,
+                     0, noopfunc, 0, 0);
+  if( rc ) return rc;
+  rc = sqlite3_create_function(db, "noop_do", 1,
+                     SQLITE_UTF8 | SQLITE_DETERMINISTIC | SQLITE_DIRECTONLY,
+                     0, noopfunc, 0, 0);
+  if( rc ) return rc;
+  rc = sqlite3_create_function(db, "noop_nd", 1,
+                     SQLITE_UTF8,
+                     0, noopfunc, 0, 0);
+  return rc;
+}