rust/src/libsyntax/attr.rs

411 lines
11 KiB
Rust

// Functions dealing with attributes and meta_items
import std::map;
import std::map::hashmap;
import either::either;
import diagnostic::span_handler;
import ast_util::{spanned, dummy_spanned};
import parse::comments::{doc_comment_style, strip_doc_comment_decoration};
// Constructors
export mk_name_value_item_str;
export mk_name_value_item;
export mk_list_item;
export mk_word_item;
export mk_attr;
export mk_sugared_doc_attr;
// Conversion
export attr_meta;
export attr_metas;
export desugar_doc_attr;
// Accessors
export get_attr_name;
export get_meta_item_name;
export get_meta_item_value_str;
export get_meta_item_list;
export get_name_value_str_pair;
// Searching
export find_attrs_by_name;
export find_meta_items_by_name;
export contains;
export contains_name;
export attrs_contains_name;
export first_attr_value_str_by_name;
export last_meta_item_value_str_by_name;
export last_meta_item_list_by_name;
// Higher-level applications
export sort_meta_items;
export remove_meta_items_by_name;
export find_linkage_attrs;
export find_linkage_metas;
export foreign_abi;
export inline_attr;
export find_inline_attr;
export require_unique_names;
/* Constructors */
fn mk_name_value_item_str(+name: ast::ident, +value: str) -> @ast::meta_item {
let value_lit = dummy_spanned(ast::lit_str(@value));
ret mk_name_value_item(name, value_lit);
}
fn mk_name_value_item(+name: ast::ident, +value: ast::lit)
-> @ast::meta_item {
ret @dummy_spanned(ast::meta_name_value(name, value));
}
fn mk_list_item(+name: ast::ident, +items: ~[@ast::meta_item]) ->
@ast::meta_item {
ret @dummy_spanned(ast::meta_list(name, items));
}
fn mk_word_item(+name: ast::ident) -> @ast::meta_item {
ret @dummy_spanned(ast::meta_word(name));
}
fn mk_attr(item: @ast::meta_item) -> ast::attribute {
ret dummy_spanned({style: ast::attr_inner, value: *item,
is_sugared_doc: false});
}
fn mk_sugared_doc_attr(text: str, lo: uint, hi: uint) -> ast::attribute {
let lit = spanned(lo, hi, ast::lit_str(@text));
let attr = {
style: doc_comment_style(text),
value: spanned(lo, hi, ast::meta_name_value(@"doc", lit)),
is_sugared_doc: true
};
ret spanned(lo, hi, attr);
}
/* Conversion */
fn attr_meta(attr: ast::attribute) -> @ast::meta_item { @attr.node.value }
// Get the meta_items from inside a vector of attributes
fn attr_metas(attrs: ~[ast::attribute]) -> ~[@ast::meta_item] {
let mut mitems = ~[];
for attrs.each |a| { vec::push(mitems, attr_meta(a)); }
ret mitems;
}
fn desugar_doc_attr(attr: ast::attribute) -> ast::attribute {
if attr.node.is_sugared_doc {
let comment = get_meta_item_value_str(@attr.node.value).get();
let meta = mk_name_value_item_str(@"doc",
strip_doc_comment_decoration(*comment));
ret mk_attr(meta);
} else {
attr
}
}
/* Accessors */
fn get_attr_name(attr: ast::attribute) -> ast::ident {
get_meta_item_name(@attr.node.value)
}
// All "bad" FIXME copies are as per #2543
fn get_meta_item_name(meta: @ast::meta_item) -> ast::ident {
alt meta.node {
ast::meta_word(n) { /* FIXME (#2543) */ copy n }
ast::meta_name_value(n, _) { /* FIXME (#2543) */ copy n }
ast::meta_list(n, _) { /* FIXME (#2543) */ copy n }
}
}
/**
* Gets the string value if the meta_item is a meta_name_value variant
* containing a string, otherwise none
*/
fn get_meta_item_value_str(meta: @ast::meta_item) -> option<@str> {
alt meta.node {
ast::meta_name_value(_, v) {
alt v.node {
ast::lit_str(s) {
option::some(s)
}
_ {
option::none
}
}
}
_ { option::none }
}
}
/// Gets a list of inner meta items from a list meta_item type
fn get_meta_item_list(meta: @ast::meta_item) -> option<~[@ast::meta_item]> {
alt meta.node {
ast::meta_list(_, l) { option::some(/* FIXME (#2543) */ copy l) }
_ { option::none }
}
}
/**
* If the meta item is a nam-value type with a string value then returns
* a tuple containing the name and string value, otherwise `none`
*/
fn get_name_value_str_pair(
item: @ast::meta_item
) -> option<(ast::ident, @str)> {
alt attr::get_meta_item_value_str(item) {
some(value) {
let name = attr::get_meta_item_name(item);
some((name, value))
}
none { none }
}
}
/* Searching */
/// Search a list of attributes and return only those with a specific name
fn find_attrs_by_name(attrs: ~[ast::attribute], +name: str) ->
~[ast::attribute] {
let filter = (
fn@(a: ast::attribute) -> option<ast::attribute> {
if *get_attr_name(a) == name {
option::some(a)
} else { option::none }
}
);
ret vec::filter_map(attrs, filter);
}
/// Searcha list of meta items and return only those with a specific name
fn find_meta_items_by_name(metas: ~[@ast::meta_item], +name: str) ->
~[@ast::meta_item] {
let filter = fn@(&&m: @ast::meta_item) -> option<@ast::meta_item> {
if *get_meta_item_name(m) == name {
option::some(m)
} else { option::none }
};
ret vec::filter_map(metas, filter);
}
/**
* Returns true if a list of meta items contains another meta item. The
* comparison is performed structurally.
*/
fn contains(haystack: ~[@ast::meta_item], needle: @ast::meta_item) -> bool {
#debug("looking for %s",
print::pprust::meta_item_to_str(*needle));
for haystack.each |item| {
#debug("looking in %s",
print::pprust::meta_item_to_str(*item));
if eq(item, needle) { #debug("found it!"); ret true; }
}
#debug("found it not :(");
ret false;
}
fn eq(a: @ast::meta_item, b: @ast::meta_item) -> bool {
ret alt a.node {
ast::meta_word(na) {
alt b.node { ast::meta_word(nb) { na == nb } _ { false } }
}
ast::meta_name_value(na, va) {
alt b.node {
ast::meta_name_value(nb, vb) { na == nb && va.node == vb.node }
_ { false }
}
}
ast::meta_list(na, la) {
// ~[Fixme-sorting]
// FIXME (#607): Needs implementing
// This involves probably sorting the list by name and
// meta_item variant
fail "unimplemented meta_item variant"
}
}
}
fn contains_name(metas: ~[@ast::meta_item], +name: str) -> bool {
let matches = find_meta_items_by_name(metas, name);
ret vec::len(matches) > 0u;
}
fn attrs_contains_name(attrs: ~[ast::attribute], +name: str) -> bool {
vec::is_not_empty(find_attrs_by_name(attrs, name))
}
fn first_attr_value_str_by_name(attrs: ~[ast::attribute], +name: str)
-> option<@str> {
let mattrs = find_attrs_by_name(attrs, name);
if vec::len(mattrs) > 0u {
ret get_meta_item_value_str(attr_meta(mattrs[0]));
}
ret option::none;
}
fn last_meta_item_by_name(
items: ~[@ast::meta_item],
+name: str
) -> option<@ast::meta_item> {
let items = attr::find_meta_items_by_name(items, name);
vec::last_opt(items)
}
fn last_meta_item_value_str_by_name(
items: ~[@ast::meta_item],
+name: str
) -> option<@str> {
alt last_meta_item_by_name(items, name) {
some(item) {
alt attr::get_meta_item_value_str(item) {
some(value) { some(value) }
none { none }
}
}
none { none }
}
}
fn last_meta_item_list_by_name(
items: ~[@ast::meta_item],
+name: str
) -> option<~[@ast::meta_item]> {
alt last_meta_item_by_name(items, name) {
some(item) {
attr::get_meta_item_list(item)
}
none { none }
}
}
/* Higher-level applications */
// FIXME (#607): This needs to sort by meta_item variant in addition to
// the item name (See [Fixme-sorting])
fn sort_meta_items(+items: ~[@ast::meta_item]) -> ~[@ast::meta_item] {
fn lteq(&&ma: @ast::meta_item, &&mb: @ast::meta_item) -> bool {
fn key(m: @ast::meta_item) -> ast::ident {
alt m.node {
ast::meta_word(name) { /* FIXME (#2543) */ copy name }
ast::meta_name_value(name, _) { /* FIXME (#2543) */ copy name }
ast::meta_list(name, _) { /* FIXME (#2543) */ copy name }
}
}
ret key(ma) <= key(mb);
}
// This is sort of stupid here, converting to a vec of mutables and back
let v: ~[mut @ast::meta_item] = vec::to_mut(items);
std::sort::quick_sort(lteq, v);
ret vec::from_mut(v);
}
fn remove_meta_items_by_name(items: ~[@ast::meta_item], name: ast::ident) ->
~[@ast::meta_item] {
ret vec::filter_map(items, |item| {
if get_meta_item_name(item) != name {
option::some(/* FIXME (#2543) */ copy item)
} else {
option::none
}
});
}
fn find_linkage_attrs(attrs: ~[ast::attribute]) -> ~[ast::attribute] {
let mut found = ~[];
for find_attrs_by_name(attrs, "link").each |attr| {
alt attr.node.value.node {
ast::meta_list(_, _) { vec::push(found, attr) }
_ { #debug("ignoring link attribute that has incorrect type"); }
}
}
ret found;
}
/**
* From a list of crate attributes get only the meta_items that impact crate
* linkage
*/
fn find_linkage_metas(attrs: ~[ast::attribute]) -> ~[@ast::meta_item] {
do find_linkage_attrs(attrs).flat_map |attr| {
alt check attr.node.value.node {
ast::meta_list(_, items) { /* FIXME (#2543) */ copy items }
}
}
}
fn foreign_abi(attrs: ~[ast::attribute]) -> either<str, ast::foreign_abi> {
ret alt attr::first_attr_value_str_by_name(attrs, "abi") {
option::none {
either::right(ast::foreign_abi_cdecl)
}
option::some(@"rust-intrinsic") {
either::right(ast::foreign_abi_rust_intrinsic)
}
option::some(@"cdecl") {
either::right(ast::foreign_abi_cdecl)
}
option::some(@"stdcall") {
either::right(ast::foreign_abi_stdcall)
}
option::some(t) {
either::left("unsupported abi: " + *t)
}
};
}
enum inline_attr {
ia_none,
ia_hint,
ia_always
}
/// True if something like #[inline] is found in the list of attrs.
fn find_inline_attr(attrs: ~[ast::attribute]) -> inline_attr {
// FIXME (#2809)---validate the usage of #[inline] and #[inline(always)]
do vec::foldl(ia_none, attrs) |ia,attr| {
alt attr.node.value.node {
ast::meta_word(@"inline") { ia_hint }
ast::meta_list(@"inline", items) {
if !vec::is_empty(find_meta_items_by_name(items, "always")) {
ia_always
} else {
ia_hint
}
}
_ { ia }
}
}
}
fn require_unique_names(diagnostic: span_handler,
metas: ~[@ast::meta_item]) {
let map = map::str_hash();
for metas.each |meta| {
let name = get_meta_item_name(meta);
// FIXME: How do I silence the warnings? --pcw (#2619)
if map.contains_key(*name) {
diagnostic.span_fatal(meta.span,
#fmt["duplicate meta item `%s`", *name]);
}
map.insert(*name, ());
}
}
//
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
//