bpo-16379: expose SQLite error codes and error names in `sqlite3` (GH-27786)

1 files changed, 78 insertions, 27 deletions

diff --git a/Modules/_sqlite/util.c b/Modules/_sqlite/util.c
index 24cefc626b6..cfd189dfc33 100644
--- a/Modules/_sqlite/util.c
+++ b/Modules/_sqlite/util.c
@@ -36,27 +36,19 @@ pysqlite_step(sqlite3_stmt *statement)
     return rc;
 }
 
-/**
- * Checks the SQLite error code and sets the appropriate DB-API exception.
- * Returns the error code (0 means no error occurred).
- */
-int
-_pysqlite_seterror(pysqlite_state *state, sqlite3 *db)
+// Returns non-NULL if a new exception should be raised
+static PyObject *
+get_exception_class(pysqlite_state *state, int errorcode)
 {
-    int errorcode = sqlite3_errcode(db);
-
-    switch (errorcode)
-    {
+    switch (errorcode) {
         case SQLITE_OK:
             PyErr_Clear();
-            break;
+            return NULL;
         case SQLITE_INTERNAL:
         case SQLITE_NOTFOUND:
-            PyErr_SetString(state->InternalError, sqlite3_errmsg(db));
-            break;
+            return state->InternalError;
         case SQLITE_NOMEM:
-            (void)PyErr_NoMemory();
-            break;
+            return PyErr_NoMemory();
         case SQLITE_ERROR:
         case SQLITE_PERM:
         case SQLITE_ABORT:
@@ -70,26 +62,85 @@ _pysqlite_seterror(pysqlite_state *state, sqlite3 *db)
         case SQLITE_PROTOCOL:
         case SQLITE_EMPTY:
         case SQLITE_SCHEMA:
-            PyErr_SetString(state->OperationalError, sqlite3_errmsg(db));
-            break;
+            return state->OperationalError;
         case SQLITE_CORRUPT:
-            PyErr_SetString(state->DatabaseError, sqlite3_errmsg(db));
-            break;
+            return state->DatabaseError;
         case SQLITE_TOOBIG:
-            PyErr_SetString(state->DataError, sqlite3_errmsg(db));
-            break;
+            return state->DataError;
         case SQLITE_CONSTRAINT:
         case SQLITE_MISMATCH:
-            PyErr_SetString(state->IntegrityError, sqlite3_errmsg(db));
-            break;
+            return state->IntegrityError;
         case SQLITE_MISUSE:
-            PyErr_SetString(state->ProgrammingError, sqlite3_errmsg(db));
-            break;
+            return state->ProgrammingError;
         default:
-            PyErr_SetString(state->DatabaseError, sqlite3_errmsg(db));
-            break;
+            return state->DatabaseError;
+    }
+}
+
+static void
+raise_exception(PyObject *type, int errcode, const char *errmsg)
+{
+    PyObject *exc = NULL;
+    PyObject *args[] = { PyUnicode_FromString(errmsg), };
+    if (args[0] == NULL) {
+        goto exit;
+    }
+    exc = PyObject_Vectorcall(type, args, 1, NULL);
+    Py_DECREF(args[0]);
+    if (exc == NULL) {
+        goto exit;
+    }
+
+    PyObject *code = PyLong_FromLong(errcode);
+    if (code == NULL) {
+        goto exit;
+    }
+    int rc = PyObject_SetAttrString(exc, "sqlite_errorcode", code);
+    Py_DECREF(code);
+    if (rc < 0) {
+        goto exit;
+    }
+
+    const char *error_name = pysqlite_error_name(errcode);
+    PyObject *name;
+    if (error_name) {
+        name = PyUnicode_FromString(error_name);
+    }
+    else {
+        name = PyUnicode_InternFromString("unknown");
+    }
+    if (name == NULL) {
+        goto exit;
+    }
+    rc = PyObject_SetAttrString(exc, "sqlite_errorname", name);
+    Py_DECREF(name);
+    if (rc < 0) {
+        goto exit;
+    }
+
+    PyErr_SetObject(type, exc);
+
+exit:
+    Py_XDECREF(exc);
+}
+
+/**
+ * Checks the SQLite error code and sets the appropriate DB-API exception.
+ * Returns the error code (0 means no error occurred).
+ */
+int
+_pysqlite_seterror(pysqlite_state *state, sqlite3 *db)
+{
+    int errorcode = sqlite3_errcode(db);
+    PyObject *exc_class = get_exception_class(state, errorcode);
+    if (exc_class == NULL) {
+        // No new exception need be raised; just pass the error code
+        return errorcode;
     }
 
+    /* Create and set the exception. */
+    const char *errmsg = sqlite3_errmsg(db);
+    raise_exception(exc_class, errorcode, errmsg);
     return errorcode;
 }