From aadbe1a7d2af5a20d19d4097cabfa458350808b6 Mon Sep 17 00:00:00 2001
From: Ryan Culpepper <ryanc@racket-lang.org>
Date: Tue, 3 Apr 2018 03:06:24 +0200
Subject: [PATCH] db/sqlite3: add support for loading extensions

---
 .../collects/db/private/sqlite3/connection.rkt | 18 +++++++++++++++++-
 racket/collects/db/private/sqlite3/ffi.rkt     | 16 ++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/racket/collects/db/private/sqlite3/connection.rkt b/racket/collects/db/private/sqlite3/connection.rkt
index a51f0fd1a2..9ecd7a4632 100644
--- a/racket/collects/db/private/sqlite3/connection.rkt
+++ b/racket/collects/db/private/sqlite3/connection.rkt
@@ -1,5 +1,6 @@
 #lang racket/base
 (require racket/class
+         ffi/file
          ffi/unsafe
          ffi/unsafe/atomic
          ffi/unsafe/custodian
@@ -10,7 +11,10 @@
          "ffi.rkt"
          "dbsystem.rkt")
 (provide connection%
-         handle-status*)
+         handle-status*
+         (protect-out unsafe-load-extension))
+
+(define-local-member-name unsafe-load-extension)
 
 ;; == Connection
 
@@ -359,6 +363,18 @@
 
     ;; ----
 
+    (define/public (unsafe-load-extension who lib)
+      (define lib-path (cleanse-path (path->complete-path lib)))
+      (security-guard-check-file who lib-path '(read execute))
+      (call-with-lock who
+        (lambda ()
+          (HANDLE who (A (sqlite3_enable_load_extension -db 1)))
+          (HANDLE who (A (sqlite3_load_extension -db lib-path)))
+          (HANDLE who (A (sqlite3_enable_load_extension -db 0)))
+          (void))))
+
+    ;; ----
+
     (define-syntax HANDLE
       (syntax-rules ()
         [(HANDLE who expr)
diff --git a/racket/collects/db/private/sqlite3/ffi.rkt b/racket/collects/db/private/sqlite3/ffi.rkt
index 2da349fe35..29831d59e0 100644
--- a/racket/collects/db/private/sqlite3/ffi.rkt
+++ b/racket/collects/db/private/sqlite3/ffi.rkt
@@ -222,3 +222,19 @@
 (define-sqlite sqlite3_last_insert_rowid
   (_fun _sqlite3_database
         -> _int64))
+
+;; ----------------------------------------
+
+(define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005) ;; int int*
+
+(define-sqlite sqlite3_db_config
+  (_fun _sqlite3_database _int _int (out : (_ptr o _int))
+        -> (r : _int) -> r)) ;; FIXME: return out?
+
+(define-sqlite sqlite3_enable_load_extension
+  (_fun _sqlite3_database _int -> _int))
+
+(define-sqlite sqlite3_load_extension
+  ;; FIXME: handle error string?
+  (_fun _sqlite3_database _path (_pointer = #f) (_pointer = #f)
+        -> _int))