internal format-style API to raise type errors easily

wjakob · Jul 3, 2023 · 1d2aa6d · 1d2aa6d
1 parent 8c75c97
commit 1d2aa6d
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Showing 4 changed files with 47 additions and 15 deletions.
diff --git a/include/nanobind/nb_error.h b/include/nanobind/nb_error.h
@@ -90,9 +90,8 @@ class NB_EXPORT python_error : public std::exception {
 using cast_error = std::bad_cast;
 
 enum class exception_type {
-    stop_iteration, index_error, key_error, value_error,
-    type_error, buffer_error, import_error, attribute_error,
-    next_overload
+    runtime_error, stop_iteration, index_error, key_error, value_error,
+    type_error, buffer_error, import_error, attribute_error, next_overload
 };
 
 // Base interface used to expose common Python exceptions in C++

diff --git a/include/nanobind/nb_lib.h b/include/nanobind/nb_lib.h
@@ -66,14 +66,22 @@ struct NB_CORE cleanup_list {
 
 // ========================================================================
 
-/// Raise a std::runtime_error with the given message
+/// Raise a runtime error with the given message
 #if defined(__GNUC__)
     __attribute__((noreturn, __format__ (__printf__, 1, 2)))
 #else
     [[noreturn]]
 #endif
 NB_CORE void raise(const char *fmt, ...);
 
+/// Raise a type error with the given message
+#if defined(__GNUC__)
+    __attribute__((noreturn, __format__ (__printf__, 1, 2)))
+#else
+    [[noreturn]]
+#endif
+NB_CORE void raise_type_error(const char *fmt, ...);
+
 /// Abort the process with a fatal error
 #if defined(__GNUC__)
     __attribute__((noreturn, __format__ (__printf__, 1, 2)))

diff --git a/src/common.cpp b/src/common.cpp
@@ -13,30 +13,54 @@
 NAMESPACE_BEGIN(NB_NAMESPACE)
 NAMESPACE_BEGIN(detail)
 
+NB_NOINLINE static builtin_exception
+create_exception(exception_type type, const char *fmt, va_list args_) {
+    char buf[512];
+    va_list args;
+
+    va_copy(args, args_);
+    int size = vsnprintf(buf, sizeof(buf), fmt, args);
+    va_end(args);
+
+    if (size < (int) sizeof(buf)) {
+        return builtin_exception(type, buf);
+    } else {
+        scoped_pymalloc<char> temp(size + 1);
+
+        va_copy(args, args_);
+        vsnprintf(temp.get(), size + 1, fmt, args);
+        va_end(args);
+
+        return builtin_exception(type, temp.get());
+    }
+}
 
 #if defined(__GNUC__)
     __attribute__((noreturn, __format__ (__printf__, 1, 2)))
 #else
     [[noreturn]]
 #endif
 void raise(const char *fmt, ...) {
-    char buf[512];
     va_list args;
-
     va_start(args, fmt);
-    int size = vsnprintf(buf, sizeof(buf), fmt, args);
+    builtin_exception err =
+        create_exception(exception_type::runtime_error, fmt, args);
     va_end(args);
+    throw err;
+}
 
-    if (size < (int) sizeof(buf))
-        throw std::runtime_error(buf);
-
-    scoped_pymalloc<char> temp(size + 1);
-
+#if defined(__GNUC__)
+    __attribute__((noreturn, __format__ (__printf__, 1, 2)))
+#else
+    [[noreturn]]
+#endif
+void raise_type_error(const char *fmt, ...) {
+    va_list args;
     va_start(args, fmt);
-    vsnprintf(temp.get(), size + 1, fmt, args);
+    builtin_exception err =
+        create_exception(exception_type::type_error, fmt, args);
     va_end(args);
-
-    throw std::runtime_error(temp.get());
+    throw err;
 }
 
 /// Abort the process with a fatal error

diff --git a/src/nb_func.cpp b/src/nb_func.cpp
@@ -141,6 +141,7 @@ static bool set_builtin_exception_status(builtin_exception &e) {
     PyObject *o;
 
     switch (e.type()) {
+        case exception_type::runtime_error: o = PyExc_RuntimeError; break;
         case exception_type::stop_iteration: o = PyExc_StopIteration; break;
         case exception_type::index_error: o = PyExc_IndexError; break;
         case exception_type::key_error: o = PyExc_KeyError; break;