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// Copyright 2018 Guillaume Pinot (@TeXitoi) <texitoi@texitoi.eu>,
// Kevin Knapp (@kbknapp) <kbknapp@gmail.com>, and
// Ana Hobden (@hoverbear) <operator@hoverbear.org>
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//
// commit#ea76fa1b1b273e65e3b0b1046643715b49bec51f which is licensed under the
// MIT/Apache 2.0 license.
use proc_macro2::{Ident, Span, TokenStream};
use quote::{format_ident, quote, quote_spanned};
use syn::{
punctuated::Punctuated, spanned::Spanned, token::Comma, Data, DataStruct, DeriveInput, Field,
Fields, FieldsNamed, Generics,
};
use crate::item::{Item, Kind, Name};
use crate::utils::{inner_type, sub_type, Sp, Ty};
pub(crate) fn derive_args(input: &DeriveInput) -> Result<TokenStream, syn::Error> {
let ident = &input.ident;
match input.data {
Data::Struct(DataStruct {
fields: Fields::Named(ref fields),
..
}) => {
let name = Name::Derived(ident.clone());
let item = Item::from_args_struct(input, name)?;
let fields = collect_args_fields(&item, fields)?;
gen_for_struct(&item, ident, &input.generics, &fields)
}
Data::Struct(DataStruct {
fields: Fields::Unit,
..
}) => {
let name = Name::Derived(ident.clone());
let item = Item::from_args_struct(input, name)?;
let fields = Punctuated::<Field, Comma>::new();
let fields = fields
.iter()
.map(|field| {
let item = Item::from_args_field(field, item.casing(), item.env_casing())?;
Ok((field, item))
})
.collect::<Result<Vec<_>, syn::Error>>()?;
gen_for_struct(&item, ident, &input.generics, &fields)
}
_ => abort_call_site!("`#[derive(Args)]` only supports non-tuple structs"),
}
}
pub(crate) fn gen_for_struct(
item: &Item,
item_name: &Ident,
generics: &Generics,
fields: &[(&Field, Item)],
) -> Result<TokenStream, syn::Error> {
if !matches!(&*item.kind(), Kind::Command(_)) {
abort! { item.kind().span(),
"`{}` cannot be used with `command`",
item.kind().name(),
}
}
let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
let constructor = gen_constructor(fields)?;
let updater = gen_updater(fields, true)?;
let raw_deprecated = raw_deprecated();
let app_var = Ident::new("__clap_app", Span::call_site());
let augmentation = gen_augment(fields, &app_var, item, false)?;
let augmentation_update = gen_augment(fields, &app_var, item, true)?;
let group_id = if item.skip_group() {
quote!(None)
} else {
let group_id = item.group_id();
quote!(Some(clap::Id::from(#group_id)))
};
Ok(quote! {
#[allow(
dead_code,
unreachable_code,
unused_variables,
unused_braces,
unused_qualifications,
)]
#[allow(
clippy::style,
clippy::complexity,
clippy::pedantic,
clippy::restriction,
clippy::perf,
clippy::deprecated,
clippy::nursery,
clippy::cargo,
clippy::suspicious_else_formatting,
clippy::almost_swapped,
clippy::redundant_locals,
)]
#[automatically_derived]
impl #impl_generics clap::FromArgMatches for #item_name #ty_generics #where_clause {
fn from_arg_matches(__clap_arg_matches: &clap::ArgMatches) -> ::std::result::Result<Self, clap::Error> {
Self::from_arg_matches_mut(&mut __clap_arg_matches.clone())
}
fn from_arg_matches_mut(__clap_arg_matches: &mut clap::ArgMatches) -> ::std::result::Result<Self, clap::Error> {
#raw_deprecated
let v = #item_name #constructor;
::std::result::Result::Ok(v)
}
fn update_from_arg_matches(&mut self, __clap_arg_matches: &clap::ArgMatches) -> ::std::result::Result<(), clap::Error> {
self.update_from_arg_matches_mut(&mut __clap_arg_matches.clone())
}
fn update_from_arg_matches_mut(&mut self, __clap_arg_matches: &mut clap::ArgMatches) -> ::std::result::Result<(), clap::Error> {
#raw_deprecated
#updater
::std::result::Result::Ok(())
}
}
#[allow(
dead_code,
unreachable_code,
unused_variables,
unused_braces,
unused_qualifications,
)]
#[allow(
clippy::style,
clippy::complexity,
clippy::pedantic,
clippy::restriction,
clippy::perf,
clippy::deprecated,
clippy::nursery,
clippy::cargo,
clippy::suspicious_else_formatting,
clippy::almost_swapped,
clippy::redundant_locals,
)]
#[automatically_derived]
impl #impl_generics clap::Args for #item_name #ty_generics #where_clause {
fn group_id() -> Option<clap::Id> {
#group_id
}
fn augment_args<'b>(#app_var: clap::Command) -> clap::Command {
#augmentation
}
fn augment_args_for_update<'b>(#app_var: clap::Command) -> clap::Command {
#augmentation_update
}
}
})
}
/// Generate a block of code to add arguments/subcommands corresponding to
/// the `fields` to an cmd.
pub(crate) fn gen_augment(
fields: &[(&Field, Item)],
app_var: &Ident,
parent_item: &Item,
override_required: bool,
) -> Result<TokenStream, syn::Error> {
let mut subcommand_specified = false;
let mut args = Vec::new();
for (field, item) in fields {
let kind = item.kind();
let genned = match &*kind {
Kind::Command(_)
| Kind::Value
| Kind::Skip(_, _)
| Kind::FromGlobal(_)
| Kind::ExternalSubcommand => None,
Kind::Subcommand(ty) => {
if subcommand_specified {
abort!(
field.span(),
"`#[command(subcommand)]` can only be used once per container"
);
}
subcommand_specified = true;
let subcmd_type = match (**ty, sub_type(&field.ty)) {
(Ty::Option, Some(sub_type)) => sub_type,
_ => &field.ty,
};
let implicit_methods = if **ty == Ty::Option {
quote!()
} else {
quote_spanned! { kind.span()=>
.subcommand_required(true)
.arg_required_else_help(true)
}
};
let override_methods = if override_required {
quote_spanned! { kind.span()=>
.subcommand_required(false)
.arg_required_else_help(false)
}
} else {
quote!()
};
Some(quote! {
let #app_var = <#subcmd_type as clap::Subcommand>::augment_subcommands( #app_var );
let #app_var = #app_var
#implicit_methods
#override_methods;
})
}
Kind::Flatten(ty) => {
let inner_type = match (**ty, sub_type(&field.ty)) {
(Ty::Option, Some(sub_type)) => sub_type,
_ => &field.ty,
};
let next_help_heading = item.next_help_heading();
let next_display_order = item.next_display_order();
let flatten_group_assert = if matches!(**ty, Ty::Option) {
quote_spanned! { kind.span()=>
<#inner_type as clap::Args>::group_id().expect("cannot `#[flatten]` an `Option<Args>` with `#[group(skip)]");
}
} else {
quote! {}
};
if override_required {
Some(quote_spanned! { kind.span()=>
#flatten_group_assert
let #app_var = #app_var
#next_help_heading
#next_display_order;
let #app_var = <#inner_type as clap::Args>::augment_args_for_update(#app_var);
})
} else {
Some(quote_spanned! { kind.span()=>
#flatten_group_assert
let #app_var = #app_var
#next_help_heading
#next_display_order;
let #app_var = <#inner_type as clap::Args>::augment_args(#app_var);
})
}
}
Kind::Arg(ty) => {
let value_parser = item.value_parser(&field.ty);
let action = item.action(&field.ty);
let value_name = item.value_name();
let implicit_methods = match **ty {
Ty::Unit => {
// Leaving out `value_parser` as it will always fail
quote_spanned! { ty.span()=>
.value_name(#value_name)
#action
}
}
Ty::Option => {
quote_spanned! { ty.span()=>
.value_name(#value_name)
#value_parser
#action
}
}
Ty::OptionOption => quote_spanned! { ty.span()=>
.value_name(#value_name)
.num_args(0..=1)
#value_parser
#action
},
Ty::OptionVec => {
if item.is_positional() {
quote_spanned! { ty.span()=>
.value_name(#value_name)
.num_args(1..) // action won't be sufficient for getting multiple
#value_parser
#action
}
} else {
quote_spanned! { ty.span()=>
.value_name(#value_name)
#value_parser
#action
}
}
}
Ty::Vec => {
if item.is_positional() {
quote_spanned! { ty.span()=>
.value_name(#value_name)
.num_args(1..) // action won't be sufficient for getting multiple
#value_parser
#action
}
} else {
quote_spanned! { ty.span()=>
.value_name(#value_name)
#value_parser
#action
}
}
}
Ty::VecVec | Ty::OptionVecVec => {
quote_spanned! { ty.span() =>
.value_name(#value_name)
#value_parser
#action
}
}
Ty::Other => {
let required = item.find_default_method().is_none();
// `ArgAction::takes_values` is assuming `ArgAction::default_value` will be
// set though that won't always be true but this should be good enough,
// otherwise we'll report an "arg required" error when unwrapping.
let action_value = action.args();
quote_spanned! { ty.span()=>
.value_name(#value_name)
.required(#required && #action_value.takes_values())
#value_parser
#action
}
}
};
let id = item.id();
let explicit_methods = item.field_methods();
let deprecations = if !override_required {
item.deprecations()
} else {
quote!()
};
let override_methods = if override_required {
quote_spanned! { kind.span()=>
.required(false)
}
} else {
quote!()
};
Some(quote_spanned! { field.span()=>
let #app_var = #app_var.arg({
#deprecations
#[allow(deprecated)]
let arg = clap::Arg::new(#id)
#implicit_methods;
let arg = arg
#explicit_methods;
let arg = arg
#override_methods;
arg
});
})
}
};
args.push(genned);
}
let deprecations = if !override_required {
parent_item.deprecations()
} else {
quote!()
};
let initial_app_methods = parent_item.initial_top_level_methods();
let final_app_methods = parent_item.final_top_level_methods();
let group_app_methods = if parent_item.skip_group() {
quote!()
} else {
let group_id = parent_item.group_id();
let literal_group_members = fields
.iter()
.filter_map(|(_field, item)| {
let kind = item.kind();
if matches!(*kind, Kind::Arg(_)) {
Some(item.id())
} else {
None
}
})
.collect::<Vec<_>>();
let literal_group_members_len = literal_group_members.len();
let mut literal_group_members = quote! {{
let members: [clap::Id; #literal_group_members_len] = [#( clap::Id::from(#literal_group_members) ),* ];
members
}};
// HACK: Validation isn't ready yet for nested arg groups, so just don't populate the group in
// that situation
let possible_group_members_len = fields
.iter()
.filter(|(_field, item)| {
let kind = item.kind();
matches!(*kind, Kind::Flatten(_))
})
.count();
if 0 < possible_group_members_len {
literal_group_members = quote! {{
let members: [clap::Id; 0] = [];
members
}};
}
let group_methods = parent_item.group_methods();
quote!(
.group(
clap::ArgGroup::new(#group_id)
.multiple(true)
#group_methods
.args(#literal_group_members)
)
)
};
Ok(quote! {{
#deprecations
let #app_var = #app_var
#initial_app_methods
#group_app_methods
;
#( #args )*
#app_var #final_app_methods
}})
}
pub(crate) fn gen_constructor(fields: &[(&Field, Item)]) -> Result<TokenStream, syn::Error> {
let fields = fields.iter().map(|(field, item)| {
let field_name = field.ident.as_ref().unwrap();
let kind = item.kind();
let arg_matches = format_ident!("__clap_arg_matches");
let genned = match &*kind {
Kind::Command(_)
| Kind::Value
| Kind::ExternalSubcommand => {
abort! { kind.span(),
"`{}` cannot be used with `arg`",
kind.name(),
}
}
Kind::Subcommand(ty) => {
let subcmd_type = match (**ty, sub_type(&field.ty)) {
(Ty::Option, Some(sub_type)) => sub_type,
_ => &field.ty,
};
match **ty {
Ty::Option => {
quote_spanned! { kind.span()=>
#field_name: {
if #arg_matches.subcommand_name().map(<#subcmd_type as clap::Subcommand>::has_subcommand).unwrap_or(false) {
Some(<#subcmd_type as clap::FromArgMatches>::from_arg_matches_mut(#arg_matches)?)
} else {
None
}
}
}
},
Ty::Other => {
quote_spanned! { kind.span()=>
#field_name: {
<#subcmd_type as clap::FromArgMatches>::from_arg_matches_mut(#arg_matches)?
}
}
},
Ty::Unit |
Ty::Vec |
Ty::OptionOption |
Ty::OptionVec |
Ty::VecVec |
Ty::OptionVecVec => {
abort!(
ty.span(),
"{} types are not supported for subcommand",
ty.as_str()
);
}
}
}
Kind::Flatten(ty) => {
let inner_type = match (**ty, sub_type(&field.ty)) {
(Ty::Option, Some(sub_type)) => sub_type,
_ => &field.ty,
};
match **ty {
Ty::Other => {
quote_spanned! { kind.span()=>
#field_name: <#inner_type as clap::FromArgMatches>::from_arg_matches_mut(#arg_matches)?
}
},
Ty::Option => {
quote_spanned! { kind.span()=>
#field_name: {
let group_id = <#inner_type as clap::Args>::group_id()
.expect("asserted during `Arg` creation");
if #arg_matches.contains_id(group_id.as_str()) {
Some(
<#inner_type as clap::FromArgMatches>::from_arg_matches_mut(#arg_matches)?
)
} else {
None
}
}
}
},
Ty::Unit |
Ty::Vec |
Ty::OptionOption |
Ty::OptionVec |
Ty::VecVec |
Ty::OptionVecVec => {
abort!(
ty.span(),
"{} types are not supported for flatten",
ty.as_str()
);
}
}
},
Kind::Skip(val, _) => match val {
None => quote_spanned!(kind.span()=> #field_name: Default::default()),
Some(val) => quote_spanned!(kind.span()=> #field_name: (#val).into()),
},
Kind::Arg(ty) | Kind::FromGlobal(ty) => {
gen_parsers(item, ty, field_name, field, None)?
}
};
Ok(genned)
}).collect::<Result<Vec<_>, syn::Error>>()?;
Ok(quote! {{
#( #fields ),*
}})
}
pub(crate) fn gen_updater(
fields: &[(&Field, Item)],
use_self: bool,
) -> Result<TokenStream, syn::Error> {
let mut genned_fields = Vec::new();
for (field, item) in fields {
let field_name = field.ident.as_ref().unwrap();
let kind = item.kind();
let access = if use_self {
quote! {
#[allow(non_snake_case)]
let #field_name = &mut self.#field_name;
}
} else {
quote!()
};
let arg_matches = format_ident!("__clap_arg_matches");
let genned = match &*kind {
Kind::Command(_) | Kind::Value | Kind::ExternalSubcommand => {
abort! { kind.span(),
"`{}` cannot be used with `arg`",
kind.name(),
}
}
Kind::Subcommand(ty) => {
let subcmd_type = match (**ty, sub_type(&field.ty)) {
(Ty::Option, Some(sub_type)) => sub_type,
_ => &field.ty,
};
let updater = quote_spanned! { ty.span()=>
<#subcmd_type as clap::FromArgMatches>::update_from_arg_matches_mut(#field_name, #arg_matches)?;
};
let updater = match **ty {
Ty::Option => quote_spanned! { kind.span()=>
if let Some(#field_name) = #field_name.as_mut() {
#updater
} else {
*#field_name = Some(<#subcmd_type as clap::FromArgMatches>::from_arg_matches_mut(
#arg_matches
)?);
}
},
_ => quote_spanned! { kind.span()=>
#updater
},
};
quote_spanned! { kind.span()=>
{
#access
#updater
}
}
}
Kind::Flatten(ty) => {
let inner_type = match (**ty, sub_type(&field.ty)) {
(Ty::Option, Some(sub_type)) => sub_type,
_ => &field.ty,
};
let updater = quote_spanned! { ty.span()=>
<#inner_type as clap::FromArgMatches>::update_from_arg_matches_mut(#field_name, #arg_matches)?;
};
let updater = match **ty {
Ty::Option => quote_spanned! { kind.span()=>
if let Some(#field_name) = #field_name.as_mut() {
#updater
} else {
*#field_name = Some(<#inner_type as clap::FromArgMatches>::from_arg_matches_mut(
#arg_matches
)?);
}
},
_ => quote_spanned! { kind.span()=>
#updater
},
};
quote_spanned! { kind.span()=>
{
#access
#updater
}
}
}
Kind::Skip(_, _) => quote!(),
Kind::Arg(ty) | Kind::FromGlobal(ty) => {
gen_parsers(item, ty, field_name, field, Some(&access))?
}
};
genned_fields.push(genned);
}
Ok(quote! {
#( #genned_fields )*
})
}
fn gen_parsers(
item: &Item,
ty: &Sp<Ty>,
field_name: &Ident,
field: &Field,
update: Option<&TokenStream>,
) -> Result<TokenStream, syn::Error> {
let span = ty.span();
let convert_type = inner_type(&field.ty);
let id = item.id();
let get_one = quote_spanned!(span=> remove_one::<#convert_type>);
let get_many = quote_spanned!(span=> remove_many::<#convert_type>);
let get_occurrences = quote_spanned!(span=> remove_occurrences::<#convert_type>);
// Give this identifier the same hygiene
// as the `arg_matches` parameter definition. This
// allows us to refer to `arg_matches` within a `quote_spanned` block
let arg_matches = format_ident!("__clap_arg_matches");
let field_value = match **ty {
Ty::Unit => {
quote_spanned! { ty.span()=>
()
}
}
Ty::Option => {
quote_spanned! { ty.span()=>
#arg_matches.#get_one(#id)
}
}
Ty::OptionOption => quote_spanned! { ty.span()=>
if #arg_matches.contains_id(#id) {
Some(
#arg_matches.#get_one(#id)
)
} else {
None
}
},
Ty::OptionVec => quote_spanned! { ty.span()=>
if #arg_matches.contains_id(#id) {
Some(#arg_matches.#get_many(#id)
.map(|v| v.collect::<Vec<_>>())
.unwrap_or_else(Vec::new))
} else {
None
}
},
Ty::Vec => {
quote_spanned! { ty.span()=>
#arg_matches.#get_many(#id)
.map(|v| v.collect::<Vec<_>>())
.unwrap_or_else(Vec::new)
}
}
Ty::VecVec => quote_spanned! { ty.span()=>
#arg_matches.#get_occurrences(#id)
.map(|g| g.map(::std::iter::Iterator::collect).collect::<Vec<Vec<_>>>())
.unwrap_or_else(Vec::new)
},
Ty::OptionVecVec => quote_spanned! { ty.span()=>
#arg_matches.#get_occurrences(#id)
.map(|g| g.map(::std::iter::Iterator::collect).collect::<Vec<Vec<_>>>())
},
Ty::Other => {
// Prefer `concat` where possible for reduced code size but fallback to `format!` to
// allow non-literal `id`s
match id {
Name::Assigned(_) => {
quote_spanned! { ty.span()=>
#arg_matches.#get_one(#id)
.ok_or_else(|| clap::Error::raw(clap::error::ErrorKind::MissingRequiredArgument, format!("The following required argument was not provided: {}", #id)))?
}
}
Name::Derived(_) => {
quote_spanned! { ty.span()=>
#arg_matches.#get_one(#id)
.ok_or_else(|| clap::Error::raw(clap::error::ErrorKind::MissingRequiredArgument, concat!("The following required argument was not provided: ", #id)))?
}
}
}
}
};
let genned = if let Some(access) = update {
quote_spanned! { field.span()=>
if #arg_matches.contains_id(#id) {
#access
*#field_name = #field_value
}
}
} else {
quote_spanned!(field.span()=> #field_name: #field_value )
};
Ok(genned)
}
#[cfg(feature = "raw-deprecated")]
pub(crate) fn raw_deprecated() -> TokenStream {
quote! {}
}
#[cfg(not(feature = "raw-deprecated"))]
pub(crate) fn raw_deprecated() -> TokenStream {
quote! {
#![allow(deprecated)] // Assuming any deprecation in here will be related to a deprecation in `Args`
}
}
pub(crate) fn collect_args_fields<'a>(
item: &'a Item,
fields: &'a FieldsNamed,
) -> Result<Vec<(&'a Field, Item)>, syn::Error> {
fields
.named
.iter()
.map(|field| {
let item = Item::from_args_field(field, item.casing(), item.env_casing())?;
Ok((field, item))
})
.collect()
}