2 files changed, 72 insertions, 0 deletions
diff --git a/third_party/rust/rusqlite/examples/load_extension.rs b/third_party/rust/rusqlite/examples/load_extension.rs
new file mode 100644
index 0000000000..9e52bb202f
--- /dev/null
+++ b/third_party/rust/rusqlite/examples/load_extension.rs
@@ -0,0 +1,22 @@
+//! Ensure loadable_extension.rs works.
+
+use rusqlite::{Connection, Result};
+
+fn main() -> Result<()> {
+    let db = Connection::open_in_memory()?;
+
+    unsafe {
+        db.load_extension_enable()?;
+        #[cfg(not(windows))]
+        db.load_extension("target/debug/examples/libloadable_extension", None)?;
+        #[cfg(windows)]
+        db.load_extension("target/debug/examples/loadable_extension", None)?;
+        db.load_extension_disable()?;
+    }
+
+    let str = db.query_row("SELECT rusqlite_test_function()", [], |row| {
+        row.get::<_, String>(0)
+    })?;
+    assert_eq!(&str, "Rusqlite extension loaded correctly!");
+    Ok(())
+}
diff --git a/third_party/rust/rusqlite/examples/loadable_extension.rs b/third_party/rust/rusqlite/examples/loadable_extension.rs
new file mode 100644
index 0000000000..e913240573
--- /dev/null
+++ b/third_party/rust/rusqlite/examples/loadable_extension.rs
@@ -0,0 +1,50 @@
+//! Adaptation of https://sqlite.org/loadext.html#programming_loadable_extensions
+use std::os::raw::{c_char, c_int};
+
+use rusqlite::ffi;
+use rusqlite::functions::FunctionFlags;
+use rusqlite::types::{ToSqlOutput, Value};
+use rusqlite::{to_sqlite_error, Connection, Result};
+
+/// # build
+/// ```sh
+/// cargo build --example loadable_extension --features "loadable_extension modern_sqlite functions vtab trace"
+/// ```
+/// # test
+/// ```sh
+/// sqlite> .log on
+/// sqlite> .load target/debug/examples/libloadable_extension.so
+/// (28) Rusqlite extension initialized
+/// sqlite> SELECT rusqlite_test_function();
+/// Rusqlite extension loaded correctly!
+/// ```
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+#[no_mangle]
+pub extern "C" fn sqlite3_extension_init(
+    db: *mut ffi::sqlite3,
+    pz_err_msg: *mut *mut c_char,
+    p_api: *mut ffi::sqlite3_api_routines,
+) -> c_int {
+    if p_api.is_null() {
+        return ffi::SQLITE_ERROR;
+    } else if let Err(err) = extension_init(db, p_api) {
+        return unsafe { to_sqlite_error(&err, pz_err_msg) };
+    }
+    ffi::SQLITE_OK
+}
+
+fn extension_init(db: *mut ffi::sqlite3, p_api: *mut ffi::sqlite3_api_routines) -> Result<()> {
+    let db = unsafe { Connection::extension_init2(db, p_api)? };
+    db.create_scalar_function(
+        "rusqlite_test_function",
+        0,
+        FunctionFlags::SQLITE_DETERMINISTIC,
+        |_ctx| {
+            Ok(ToSqlOutput::Owned(Value::Text(
+                "Rusqlite extension loaded correctly!".to_string(),
+            )))
+        },
+    )?;
+    rusqlite::trace::log(ffi::SQLITE_WARNING, "Rusqlite extension initialized");
+    Ok(())
+}