use std::iter::zip;
use cairo_lang_defs::patcher::{PatchBuilder, RewriteNode};
use cairo_lang_defs::plugin::{
MacroPlugin, MacroPluginMetadata, PluginDiagnostic, PluginGeneratedFile, PluginResult,
};
use cairo_lang_filesystem::ids::SmolStrId;
use cairo_lang_syntax::attribute::structured::{AttributeArgVariant, AttributeStructurize};
use cairo_lang_syntax::node::helpers::{BodyItems, GenericParamEx, QueryAttrs};
use cairo_lang_syntax::node::{Terminal, TypedSyntaxNode, ast};
use itertools::Itertools;
use salsa::Database;
#[derive(Debug, Default)]
#[non_exhaustive]
pub struct GenerateTraitPlugin;
const GENERATE_TRAIT_ATTR: &str = "generate_trait";
impl MacroPlugin for GenerateTraitPlugin {
fn generate_code<'db>(
&self,
db: &'db dyn Database,
item_ast: ast::ModuleItem<'db>,
_metadata: &MacroPluginMetadata<'_>,
) -> PluginResult<'db> {
match item_ast {
ast::ModuleItem::Impl(impl_ast) => generate_trait_for_impl(db, impl_ast),
module_item => {
let mut diagnostics = vec![];
if let Some(attr) = module_item.find_attr(db, GENERATE_TRAIT_ATTR) {
diagnostics.push(PluginDiagnostic::warning(
attr.stable_ptr(db),
"`generate_trait` may only be applied to `impl`s".to_string(),
));
}
PluginResult { diagnostics, ..PluginResult::default() }
}
}
}
fn declared_attributes<'db>(&self, db: &'db dyn Database) -> Vec<SmolStrId<'db>> {
vec![SmolStrId::from(db, GENERATE_TRAIT_ATTR)]
}
}
fn generate_trait_for_impl<'db>(
db: &'db dyn Database,
impl_ast: ast::ItemImpl<'db>,
) -> PluginResult<'db> {
let Some(attr) = impl_ast.attributes(db).find_attr(db, GENERATE_TRAIT_ATTR) else {
return PluginResult::default();
};
let trait_ast = impl_ast.trait_path(db);
let Ok(trait_ast_segment) = trait_ast.segments(db).elements(db).exactly_one() else {
return PluginResult {
code: None,
diagnostics: vec![PluginDiagnostic::error(
trait_ast.stable_ptr(db),
"Generated trait must have a single element path.".to_string(),
)],
remove_original_item: false,
};
};
let mut diagnostics = vec![];
let mut builder = PatchBuilder::new(db, &impl_ast);
let leading_trivia = impl_ast
.attributes(db)
.elements(db)
.next()
.unwrap()
.hash(db)
.leading_trivia(db)
.as_syntax_node()
.get_text(db);
let extra_ident = leading_trivia.split('\n').next_back().unwrap_or_default();
for attr_arg in attr.structurize(db).args {
match attr_arg.variant {
AttributeArgVariant::Unnamed(ast::Expr::FunctionCall(attr_arg))
if attr_arg.path(db).as_syntax_node().get_text_without_trivia(db).long(db)
== "trait_attrs" =>
{
for arg in attr_arg.arguments(db).arguments(db).elements(db) {
builder.add_modified(RewriteNode::interpolate_patched(
&format!("{extra_ident}#[$attr$]\n"),
&[("attr".to_string(), RewriteNode::from_ast_trimmed(&arg))].into(),
));
}
}
_ => {
diagnostics.push(PluginDiagnostic::error(
attr_arg.arg.stable_ptr(db),
"Expected an argument with the name `trait_attrs`.".to_string(),
));
}
}
}
builder.add_str(extra_ident);
builder.add_node(impl_ast.visibility(db).as_syntax_node());
builder.add_str("trait ");
let impl_generic_params = impl_ast.generic_params(db);
let generic_params_match = match trait_ast_segment {
ast::PathSegment::WithGenericArgs(segment) => {
let generic_args = segment.generic_args(db).generic_args(db);
builder.add_node(segment.ident(db).as_syntax_node());
if let ast::OptionWrappedGenericParamList::WrappedGenericParamList(
impl_generic_params,
) = impl_generic_params.clone()
{
let trait_generic_args = generic_args.elements(db);
let longer_lived = impl_generic_params.generic_params(db);
let impl_generic_params = longer_lived.elements(db);
zip(trait_generic_args, impl_generic_params).all(
|(trait_generic_arg, impl_generic_param)| {
let ast::GenericArg::Unnamed(trait_generic_arg) = trait_generic_arg else {
return false;
};
let ast::Expr::Path(trait_generic_arg) = trait_generic_arg.value(db) else {
return false;
};
let Ok(ast::PathSegment::Simple(trait_generic_arg)) =
trait_generic_arg.segments(db).elements(db).exactly_one()
else {
return false;
};
let trait_generic_arg_name = trait_generic_arg.ident(db);
let Some(impl_generic_param_name) = impl_generic_param.name(db) else {
return false;
};
trait_generic_arg_name.text(db) == impl_generic_param_name.text(db)
},
)
} else {
false
}
}
ast::PathSegment::Simple(segment) => {
builder.add_node(segment.ident(db).as_syntax_node());
matches!(impl_generic_params, ast::OptionWrappedGenericParamList::Empty(_))
}
ast::PathSegment::Missing(_) => {
return PluginResult {
code: None,
diagnostics: vec![PluginDiagnostic::error(
trait_ast.stable_ptr(db),
"Generated trait cannot have a missing path segment.".to_string(),
)],
remove_original_item: false,
};
}
};
if !generic_params_match {
diagnostics.push(PluginDiagnostic::error(
trait_ast.stable_ptr(db),
"Generated trait must have generic args matching the impl's generic params."
.to_string(),
));
}
match impl_ast.body(db) {
ast::MaybeImplBody::None(semicolon) => {
builder.add_modified(RewriteNode::from_ast_trimmed(&impl_generic_params));
builder.add_node(semicolon.as_syntax_node());
}
ast::MaybeImplBody::Some(body) => {
builder.add_node(impl_generic_params.as_syntax_node());
builder.add_node(body.lbrace(db).as_syntax_node());
for item in body.iter_items(db) {
match item {
ast::ImplItem::Function(function_item) => {
let decl = function_item.declaration(db);
let signature = decl.signature(db);
builder.add_node(function_item.attributes(db).as_syntax_node());
builder.add_node(decl.optional_const(db).as_syntax_node());
builder.add_node(decl.function_kw(db).as_syntax_node());
builder.add_node(decl.name(db).as_syntax_node());
builder.add_node(decl.generic_params(db).as_syntax_node());
builder.add_node(signature.lparen(db).as_syntax_node());
for node in signature.parameters(db).node.get_children(db).iter() {
if let Some(param) = ast::Param::cast(db, *node) {
for modifier in param.modifiers(db).elements(db) {
if !matches!(modifier, ast::Modifier::Mut(_)) {
builder.add_node(modifier.as_syntax_node());
}
}
builder.add_node(param.name(db).as_syntax_node());
builder.add_node(param.type_clause(db).as_syntax_node());
} else {
builder.add_node(*node);
}
}
let rparen = signature.rparen(db);
let ret_ty = signature.ret_ty(db);
let implicits_clause = signature.implicits_clause(db);
let optional_no_panic = signature.optional_no_panic(db);
let last_node = if matches!(
optional_no_panic,
ast::OptionTerminalNoPanic::TerminalNoPanic(_)
) {
builder.add_node(rparen.as_syntax_node());
builder.add_node(ret_ty.as_syntax_node());
builder.add_node(implicits_clause.as_syntax_node());
optional_no_panic.as_syntax_node()
} else if matches!(
implicits_clause,
ast::OptionImplicitsClause::ImplicitsClause(_)
) {
builder.add_node(rparen.as_syntax_node());
builder.add_node(ret_ty.as_syntax_node());
implicits_clause.as_syntax_node()
} else if matches!(ret_ty, ast::OptionReturnTypeClause::ReturnTypeClause(_))
{
builder.add_node(rparen.as_syntax_node());
ret_ty.as_syntax_node()
} else {
rparen.as_syntax_node()
};
builder.add_modified(RewriteNode::Trimmed {
node: last_node,
trim_left: false,
trim_right: true,
});
builder.add_str(";\n");
}
ast::ImplItem::Type(type_item) => {
builder.add_node(type_item.attributes(db).as_syntax_node());
builder.add_node(type_item.type_kw(db).as_syntax_node());
builder.add_modified(RewriteNode::Trimmed {
node: type_item.name(db).as_syntax_node(),
trim_left: false,
trim_right: true,
});
builder.add_str(";\n");
}
ast::ImplItem::Constant(const_item) => {
builder.add_node(const_item.attributes(db).as_syntax_node());
builder.add_node(const_item.const_kw(db).as_syntax_node());
builder.add_node(const_item.name(db).as_syntax_node());
builder.add_modified(RewriteNode::Trimmed {
node: const_item.type_clause(db).as_syntax_node(),
trim_left: false,
trim_right: true,
});
builder.add_str(";\n");
}
_ => diagnostics.push(PluginDiagnostic::error(
item.stable_ptr(db),
"Only functions, types, and constants are supported in #[generate_trait]."
.to_string(),
)),
}
}
builder.add_node(body.rbrace(db).as_syntax_node());
}
}
let (content, code_mappings) = builder.build();
PluginResult {
code: Some(PluginGeneratedFile {
name: "generate_trait".into(),
content,
code_mappings,
aux_data: None,
diagnostics_note: Default::default(),
is_unhygienic: false,
}),
diagnostics,
remove_original_item: false,
}
}