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youknowoneyouknowone
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Merge pull request #2897 from sobolevn/better-exceptions
Adds better exception macro
2 parents aff0e3c + a725e2b commit 67b3388

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8 files changed

+275
-25
lines changed

8 files changed

+275
-25
lines changed

‎derive/src/lib.rs

Lines changed: 7 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -41,6 +41,13 @@ pub fn pyclass(attr: TokenStream, item: TokenStream) -> TokenStream {
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result_to_tokens(pyclass::impl_pyclass(attr, item))
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}
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44+
#[proc_macro_attribute]
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pub fn pyexception(attr: TokenStream, item: TokenStream) -> TokenStream {
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let attr = parse_macro_input!(attr as AttributeArgs);
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let item = parse_macro_input!(item as Item);
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result_to_tokens(pyclass::impl_pyexception(attr, item))
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}
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#[proc_macro_attribute]
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pub fn pyimpl(attr: TokenStream, item: TokenStream) -> TokenStream {
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let attr = parse_macro_input!(attr as AttributeArgs);

‎derive/src/pyclass.rs

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Original file line numberDiff line numberDiff line change
@@ -258,6 +258,36 @@ pub(crate) fn impl_pyclass(
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Ok(ret)
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}
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/// Special macro to create exception types.
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///
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/// Why do we need it and why can't we just use `pyclass` macro instead?
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/// We generate exception types with a `macro_rules`,
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/// similar to how CPython does it.
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/// But, inside `macro_rules` we don't have an opportunity
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/// to add non-literal attributes to `pyclass`.
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/// That's why we have to use this proxy.
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pub(crate) fn impl_pyexception(
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attr: AttributeArgs,
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item: Item,
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) -> std::result::Result<TokenStream, Diagnostic> {
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let class_name = parse_vec_ident(&attr, &item, 0, "first 'class_name'")?;
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let base_class_name = parse_vec_ident(&attr, &item, 1, "second 'base_class_name'")?;
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// We also need to strip `Py` prefix from `class_name`,
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// due to implementation and Python naming conventions mismatch:
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// `PyKeyboardInterrupt` -> `KeyboardInterrupt`
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let class_name = class_name.strip_prefix("Py").ok_or_else(|| {
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syn::Error::new_spanned(&item, "We require 'class_name' to have 'Py' prefix")
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})?;
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// We just "proxy" it into `pyclass` macro, because, exception is a class.
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let ret = quote! {
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#[pyclass(module = false, name = #class_name, base = #base_class_name)]
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#item
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};
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Ok(ret)
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}
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/// #[pymethod] and #[pyclassmethod]
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struct MethodItem {
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inner: ContentItemInner,
@@ -973,3 +1003,24 @@ where
9731003
}
9741004
Ok((result, cfgs))
9751005
}
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fn parse_vec_ident(
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attr: &[NestedMeta],
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item: &Item,
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index: usize,
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message: &str,
1012+
) -> std::result::Result<String, Diagnostic> {
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Ok(attr
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.get(index)
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.ok_or_else(|| {
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syn::Error::new_spanned(&item, format!("We require {} argument to be set", &message))
1017+
})?
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.get_ident()
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.ok_or_else(|| {
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syn::Error::new_spanned(
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&item,
1022+
format!("We require {} argument to be ident or string", &message),
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)
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})?
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.to_string())
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}

‎derive/src/pymodule.rs

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -109,6 +109,7 @@ fn new_module_item(
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inner: ContentItemInner { index, attr_name },
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pyattrs: pyattrs.unwrap_or_else(Vec::new),
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}),
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"pyexception" => unreachable!("#[pyexception] {:?}", pyattrs.unwrap_or_else(Vec::new)),
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other => unreachable!("#[pymodule] doesn't accept #[{}]", other),
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}
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}

‎derive/src/util.rs

Lines changed: 3 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -12,6 +12,7 @@ pub(crate) const ALL_ALLOWED_NAMES: &[&str] = &[
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"pyproperty",
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"pyfunction",
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"pyclass",
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"pyexception",
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"pystruct_sequence",
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"pyattr",
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"pyslot",
@@ -96,7 +97,7 @@ impl ItemMetaInner {
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Err(syn::Error::new_spanned(
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ident,
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format!(
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"#[{}({})] is not one of allowed attributes {}",
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"#[{}({})] is not one of allowed attributes [{}]",
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meta_ident.to_string(),
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name,
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allowed_names.join(", ")
@@ -300,7 +301,7 @@ impl ClassItemMeta {
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}.map_err(|span| syn::Error::new(
301302
span,
302303
format!(
303-
"#[{attr_name}(module = ...)] must exist as a string or false. Try #[{attr_name}(module=false)] for built-in types.",
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"#[{attr_name}(module = ...)] must exist as a string or false. Try #[{attr_name}(module = false)] for built-in types.",
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attr_name=inner.meta_name()
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),
306307
))?;

‎extra_tests/snippets/builtin_exceptions.py

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Original file line numberDiff line numberDiff line change
@@ -152,3 +152,46 @@ class SubError(MyError):
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assert isinstance(exc, MyError)
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assert exc.__cause__ is None
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assert exc.__context__ is e
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# Regression to
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# https://github.com/RustPython/RustPython/issues/2771
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160+
# `BaseException` and `Exception`:
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assert BaseException.__new__.__qualname__ == 'BaseException.__new__'
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assert BaseException.__init__.__qualname__ == 'BaseException.__init__'
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assert BaseException().__dict__ == {}
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assert BaseException.__doc__
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assert Exception.__new__.__qualname__ == 'Exception.__new__'
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assert Exception.__init__.__qualname__ == 'Exception.__init__'
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assert Exception().__dict__ == {}
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assert Exception.__doc__
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# Extends `BaseException`, simple:
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assert KeyboardInterrupt.__new__.__qualname__ == 'KeyboardInterrupt.__new__'
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assert KeyboardInterrupt.__init__.__qualname__ == 'KeyboardInterrupt.__init__'
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assert KeyboardInterrupt().__dict__ == {}
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assert KeyboardInterrupt.__doc__
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178+
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# Extends `Exception`, simple:
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assert TypeError.__new__.__qualname__ == 'TypeError.__new__'
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assert TypeError.__init__.__qualname__ == 'TypeError.__init__'
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assert TypeError().__dict__ == {}
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assert TypeError.__doc__
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185+
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# Extends `Exception`, complex:
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assert OSError.__new__.__qualname__ == 'OSError.__new__'
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assert OSError.__init__.__qualname__ == 'OSError.__init__'
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assert OSError().__dict__ == {}
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assert OSError.__doc__
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assert OSError.errno
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assert OSError.strerror
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assert OSError(1, 2).errno
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assert OSError(1, 2).strerror
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196+
assert ImportError.__init__.__qualname__ == 'ImportError.__init__'
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assert ImportError(name='a').name == 'a'

‎vm/src/builtins/dict.rs

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -692,7 +692,7 @@ macro_rules! dict_iterator {
692692
}
693693
}
694694

695-
#[pyclass(module=false,name = $iter_class_name)]
695+
#[pyclass(module = false, name = $iter_class_name)]
696696
#[derive(Debug)]
697697
pub(crate) struct $iter_name {
698698
pub dict: PyDictRef,
@@ -752,7 +752,7 @@ macro_rules! dict_iterator {
752752
}
753753
}
754754

755-
#[pyclass(module=false,name = $reverse_iter_class_name)]
755+
#[pyclass(module = false, name = $reverse_iter_class_name)]
756756
#[derive(Debug)]
757757
pub(crate) struct $reverse_iter_name {
758758
pub dict: PyDictRef,

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