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Diffstat (limited to 'src/bindgen/utilities.rs')
| -rw-r--r-- | src/bindgen/utilities.rs | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/src/bindgen/utilities.rs b/src/bindgen/utilities.rs new file mode 100644 index 0000000..0e314b9 --- /dev/null +++ b/src/bindgen/utilities.rs @@ -0,0 +1,348 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#![allow(clippy::redundant_closure_call)] + +use syn::ext::IdentExt; + +pub trait IterHelpers: Iterator { + fn try_skip_map<F, T, E>(&mut self, f: F) -> Result<Vec<T>, E> + where + F: FnMut(&Self::Item) -> Result<Option<T>, E>; +} + +impl<I> IterHelpers for I +where + I: Iterator, +{ + fn try_skip_map<F, T, E>(&mut self, mut f: F) -> Result<Vec<T>, E> + where + F: FnMut(&Self::Item) -> Result<Option<T>, E>, + { + let mut out = Vec::new(); + for item in self { + if let Some(x) = f(&item)? { + out.push(x); + } + } + Ok(out) + } +} + +pub trait SynItemHelpers: SynAttributeHelpers { + fn exported_name(&self) -> Option<String>; +} + +impl SynItemHelpers for syn::ItemFn { + fn exported_name(&self) -> Option<String> { + self.attrs + .attr_name_value_lookup("export_name") + .or_else(|| { + if self.is_no_mangle() { + Some(self.sig.ident.unraw().to_string()) + } else { + None + } + }) + } +} + +impl SynItemHelpers for syn::ImplItemMethod { + fn exported_name(&self) -> Option<String> { + self.attrs + .attr_name_value_lookup("export_name") + .or_else(|| { + if self.is_no_mangle() { + Some(self.sig.ident.unraw().to_string()) + } else { + None + } + }) + } +} + +impl SynItemHelpers for syn::ItemStatic { + fn exported_name(&self) -> Option<String> { + self.attrs + .attr_name_value_lookup("export_name") + .or_else(|| { + if self.is_no_mangle() { + Some(self.ident.unraw().to_string()) + } else { + None + } + }) + } +} + +/// Returns whether this attribute causes us to skip at item. This basically +/// checks for `#[cfg(test)]`, `#[test]`, `/// cbindgen::ignore` and +/// variations thereof. +fn is_skip_item_attr(attr: &syn::Meta) -> bool { + match *attr { + syn::Meta::Path(ref path) => { + // TODO(emilio): It'd be great if rustc allowed us to use a syntax + // like `#[cbindgen::ignore]` or such. + path.is_ident("test") + } + syn::Meta::List(ref list) => { + if !list.path.is_ident("cfg") { + return false; + } + list.nested.iter().any(|nested| match *nested { + syn::NestedMeta::Meta(ref meta) => is_skip_item_attr(meta), + syn::NestedMeta::Lit(..) => false, + }) + } + syn::Meta::NameValue(ref name_value) => { + if name_value.path.is_ident("doc") { + if let syn::Lit::Str(ref content) = name_value.lit { + // FIXME(emilio): Maybe should use the general annotation + // mechanism, but it seems overkill for this. + if content.value().trim() == "cbindgen:ignore" { + return true; + } + } + } + false + } + } +} + +pub trait SynAttributeHelpers { + /// Returns the list of attributes for an item. + fn attrs(&self) -> &[syn::Attribute]; + + /// Searches for attributes like `#[test]`. + /// Example: + /// - `item.has_attr_word("test")` => `#[test]` + fn has_attr_word(&self, name: &str) -> bool { + self.attrs() + .iter() + .filter_map(|x| x.parse_meta().ok()) + .any(|attr| { + if let syn::Meta::Path(ref path) = attr { + path.is_ident(name) + } else { + false + } + }) + } + + fn find_deprecated_note(&self) -> Option<String> { + let attrs = self.attrs(); + // #[deprecated = ""] + if let Some(note) = attrs.attr_name_value_lookup("deprecated") { + return Some(note); + } + + // #[deprecated] + if attrs.has_attr_word("deprecated") { + return Some(String::new()); + } + + // #[deprecated(note = "")] + let attr = attrs.iter().find(|attr| { + if let Ok(syn::Meta::List(list)) = attr.parse_meta() { + list.path.is_ident("deprecated") + } else { + false + } + })?; + + let args: syn::punctuated::Punctuated<syn::MetaNameValue, Token![,]> = + match attr.parse_args_with(syn::punctuated::Punctuated::parse_terminated) { + Ok(args) => args, + Err(_) => { + warn!("couldn't parse deprecated attribute"); + return None; + } + }; + + let arg = args.iter().find(|arg| arg.path.is_ident("note"))?; + if let syn::Lit::Str(ref lit) = arg.lit { + Some(lit.value()) + } else { + warn!("deprecated attribute must be a string"); + None + } + } + + fn is_no_mangle(&self) -> bool { + self.has_attr_word("no_mangle") + } + + /// Sees whether we should skip parsing a given item. + fn should_skip_parsing(&self) -> bool { + for attr in self.attrs() { + let meta = match attr.parse_meta() { + Ok(attr) => attr, + Err(..) => return false, + }; + if is_skip_item_attr(&meta) { + return true; + } + } + + false + } + + fn attr_name_value_lookup(&self, name: &str) -> Option<String> { + self.attrs() + .iter() + .filter_map(|attr| { + let attr = attr.parse_meta().ok()?; + if let syn::Meta::NameValue(syn::MetaNameValue { + path, + lit: syn::Lit::Str(lit), + .. + }) = attr + { + if path.is_ident(name) { + return Some(lit.value()); + } + } + None + }) + .next() + } + + fn get_comment_lines(&self) -> Vec<String> { + let mut comment = Vec::new(); + + for attr in self.attrs() { + if attr.style == syn::AttrStyle::Outer { + if let Ok(syn::Meta::NameValue(syn::MetaNameValue { + path, + lit: syn::Lit::Str(content), + .. + })) = attr.parse_meta() + { + if path.is_ident("doc") { + comment.extend(split_doc_attr(&content.value())); + } + } + } + } + + comment + } +} + +macro_rules! syn_item_match_helper { + ($s:ident => has_attrs: |$i:ident| $a:block, otherwise: || $b:block) => { + match *$s { + syn::Item::Const(ref $i) => $a, + syn::Item::Enum(ref $i) => $a, + syn::Item::ExternCrate(ref $i) => $a, + syn::Item::Fn(ref $i) => $a, + syn::Item::ForeignMod(ref $i) => $a, + syn::Item::Impl(ref $i) => $a, + syn::Item::Macro(ref $i) => $a, + syn::Item::Macro2(ref $i) => $a, + syn::Item::Mod(ref $i) => $a, + syn::Item::Static(ref $i) => $a, + syn::Item::Struct(ref $i) => $a, + syn::Item::Trait(ref $i) => $a, + syn::Item::Type(ref $i) => $a, + syn::Item::Union(ref $i) => $a, + syn::Item::Use(ref $i) => $a, + syn::Item::TraitAlias(ref $i) => $a, + syn::Item::Verbatim(_) => $b, + _ => panic!("Unhandled syn::Item: {:?}", $s), + } + }; +} + +impl SynAttributeHelpers for syn::Item { + fn attrs(&self) -> &[syn::Attribute] { + syn_item_match_helper!(self => + has_attrs: |item| { &item.attrs }, + otherwise: || { &[] } + ) + } +} + +macro_rules! impl_syn_item_helper { + ($t:ty) => { + impl SynAttributeHelpers for $t { + fn attrs(&self) -> &[syn::Attribute] { + &self.attrs + } + } + }; +} + +impl_syn_item_helper!(syn::ItemExternCrate); +impl_syn_item_helper!(syn::ItemUse); +impl_syn_item_helper!(syn::ItemStatic); +impl_syn_item_helper!(syn::ItemConst); +impl_syn_item_helper!(syn::ItemFn); +impl_syn_item_helper!(syn::ImplItemMethod); +impl_syn_item_helper!(syn::ItemMod); +impl_syn_item_helper!(syn::ItemForeignMod); +impl_syn_item_helper!(syn::ItemType); +impl_syn_item_helper!(syn::ItemStruct); +impl_syn_item_helper!(syn::ItemEnum); +impl_syn_item_helper!(syn::ItemUnion); +impl_syn_item_helper!(syn::ItemTrait); +impl_syn_item_helper!(syn::ItemImpl); +impl_syn_item_helper!(syn::ItemMacro); +impl_syn_item_helper!(syn::ItemMacro2); +impl_syn_item_helper!(syn::ItemTraitAlias); + +/// Helper function for accessing Abi information +pub trait SynAbiHelpers { + fn is_c(&self) -> bool; + fn is_omitted(&self) -> bool; +} + +impl SynAbiHelpers for Option<syn::Abi> { + fn is_c(&self) -> bool { + if let Some(ref abi) = *self { + if let Some(ref lit_string) = abi.name { + return matches!(lit_string.value().as_str(), "C" | "C-unwind"); + } + } + false + } + fn is_omitted(&self) -> bool { + if let Some(ref abi) = *self { + abi.name.is_none() + } else { + false + } + } +} + +impl SynAbiHelpers for syn::Abi { + fn is_c(&self) -> bool { + if let Some(ref lit_string) = self.name { + matches!(lit_string.value().as_str(), "C" | "C-unwind") + } else { + false + } + } + fn is_omitted(&self) -> bool { + self.name.is_none() + } +} + +impl SynAttributeHelpers for [syn::Attribute] { + fn attrs(&self) -> &[syn::Attribute] { + self + } +} + +fn split_doc_attr(input: &str) -> Vec<String> { + input + // Convert two newline (indicate "new paragraph") into two line break. + .replace("\n\n", " \n \n") + // Convert newline after two spaces (indicate "line break") into line break. + .split(" \n") + // Convert single newline (indicate hard-wrapped) into space. + .map(|s| s.replace('\n', " ")) + .map(|s| s.trim_end().to_string()) + .collect() +} |