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

3 files changed, 153 insertions, 29 deletions

diff --git a/Modules/_sqlite/module.c b/Modules/_sqlite/module.c
index 993e572..47b1f7a 100644
--- a/Modules/_sqlite/module.c
+++ b/Modules/_sqlite/module.c
@@ -282,12 +282,79 @@ static PyMethodDef module_methods[] = {
     {NULL, NULL}
 };
 
+/* SQLite API error codes */
+static const struct {
+    const char *name;
+    long value;
+} error_codes[] = {
+#define DECLARE_ERROR_CODE(code) {#code, code}
+    // Primary result code list
+    DECLARE_ERROR_CODE(SQLITE_ABORT),
+    DECLARE_ERROR_CODE(SQLITE_AUTH),
+    DECLARE_ERROR_CODE(SQLITE_BUSY),
+    DECLARE_ERROR_CODE(SQLITE_CANTOPEN),
+    DECLARE_ERROR_CODE(SQLITE_CONSTRAINT),
+    DECLARE_ERROR_CODE(SQLITE_CORRUPT),
+    DECLARE_ERROR_CODE(SQLITE_DONE),
+    DECLARE_ERROR_CODE(SQLITE_EMPTY),
+    DECLARE_ERROR_CODE(SQLITE_ERROR),
+    DECLARE_ERROR_CODE(SQLITE_FORMAT),
+    DECLARE_ERROR_CODE(SQLITE_FULL),
+    DECLARE_ERROR_CODE(SQLITE_INTERNAL),
+    DECLARE_ERROR_CODE(SQLITE_INTERRUPT),
+    DECLARE_ERROR_CODE(SQLITE_IOERR),
+    DECLARE_ERROR_CODE(SQLITE_LOCKED),
+    DECLARE_ERROR_CODE(SQLITE_MISMATCH),
+    DECLARE_ERROR_CODE(SQLITE_MISUSE),
+    DECLARE_ERROR_CODE(SQLITE_NOLFS),
+    DECLARE_ERROR_CODE(SQLITE_NOMEM),
+    DECLARE_ERROR_CODE(SQLITE_NOTADB),
+    DECLARE_ERROR_CODE(SQLITE_NOTFOUND),
+    DECLARE_ERROR_CODE(SQLITE_OK),
+    DECLARE_ERROR_CODE(SQLITE_PERM),
+    DECLARE_ERROR_CODE(SQLITE_PROTOCOL),
+    DECLARE_ERROR_CODE(SQLITE_READONLY),
+    DECLARE_ERROR_CODE(SQLITE_ROW),
+    DECLARE_ERROR_CODE(SQLITE_SCHEMA),
+    DECLARE_ERROR_CODE(SQLITE_TOOBIG),
+#if SQLITE_VERSION_NUMBER >= 3007017
+    DECLARE_ERROR_CODE(SQLITE_NOTICE),
+    DECLARE_ERROR_CODE(SQLITE_WARNING),
+#endif
+#undef DECLARE_ERROR_CODE
+    {NULL, 0},
+};
+
+static int
+add_error_constants(PyObject *module)
+{
+    for (int i = 0; error_codes[i].name != NULL; i++) {
+        const char *name = error_codes[i].name;
+        const long value = error_codes[i].value;
+        if (PyModule_AddIntConstant(module, name, value) < 0) {
+            return -1;
+        }
+    }
+    return 0;
+}
+
+const char *
+pysqlite_error_name(int rc)
+{
+    for (int i = 0; error_codes[i].name != NULL; i++) {
+        if (error_codes[i].value == rc) {
+            return error_codes[i].name;
+        }
+    }
+    // No error code matched.
+    return NULL;
+}
+
 static int add_integer_constants(PyObject *module) {
     int ret = 0;
 
     ret += PyModule_AddIntMacro(module, PARSE_DECLTYPES);
     ret += PyModule_AddIntMacro(module, PARSE_COLNAMES);
-    ret += PyModule_AddIntMacro(module, SQLITE_OK);
     ret += PyModule_AddIntMacro(module, SQLITE_DENY);
     ret += PyModule_AddIntMacro(module, SQLITE_IGNORE);
     ret += PyModule_AddIntMacro(module, SQLITE_CREATE_INDEX);
@@ -325,7 +392,6 @@ static int add_integer_constants(PyObject *module) {
 #if SQLITE_VERSION_NUMBER >= 3008003
     ret += PyModule_AddIntMacro(module, SQLITE_RECURSIVE);
 #endif
-    ret += PyModule_AddIntMacro(module, SQLITE_DONE);
     return ret;
 }
 
@@ -406,6 +472,11 @@ PyMODINIT_FUNC PyInit__sqlite3(void)
     ADD_EXCEPTION(module, state, DataError, state->DatabaseError);
     ADD_EXCEPTION(module, state, NotSupportedError, state->DatabaseError);
 
+    /* Set error constants */
+    if (add_error_constants(module) < 0) {
+        goto error;
+    }
+
     /* Set integer constants */
     if (add_integer_constants(module) < 0) {
         goto error;
diff --git a/Modules/_sqlite/module.h b/Modules/_sqlite/module.h
index a286739..c273c1f 100644
--- a/Modules/_sqlite/module.h
+++ b/Modules/_sqlite/module.h
@@ -81,6 +81,8 @@ pysqlite_get_state_by_type(PyTypeObject *Py_UNUSED(tp))
     return &pysqlite_global_state;
 }
 
+extern const char *pysqlite_error_name(int rc);
+
 #define PARSE_DECLTYPES 1
 #define PARSE_COLNAMES 2
 #endif
diff --git a/Modules/_sqlite/util.c b/Modules/_sqlite/util.c
index 24cefc6..cfd189d 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;
 }