mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Refactor away the CfgFolder trait.

Browse Source
This commit is contained in:
Jeffrey Seyfried 2016-06-01 02:13:45 +00:00
parent c89846c271
commit 29c4b6726a
1 changed files with 18 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
src/libsyntax/config.rs
View File

@ -19,27 +19,7 @@ use ptr::P;
use util::small_vector::SmallVector;
pub trait CfgFolder: fold::Folder {
// Check if a node with the given attributes is in this configuration.
fn in_cfg(&mut self, attrs: &[ast::Attribute]) -> bool;
// Update a node before checking if it is in this configuration (used to implement `cfg_attr`).
fn process_attrs<T: HasAttrs>(&mut self, node: T) -> T { node }
// Visit attributes on expression and statements (but not attributes on items in blocks).
fn visit_stmt_or_expr_attrs(&mut self, _attrs: &[ast::Attribute]) {}
// Visit unremovable (non-optional) expressions -- c.f. `fold_expr` vs `fold_opt_expr`.
fn visit_unremovable_expr(&mut self, _expr: &ast::Expr) {}
fn configure<T: HasAttrs>(&mut self, node: T) -> Option<T> {
let node = self.process_attrs(node);
if self.in_cfg(node.attrs()) { Some(node) } else { None }
}
}
/// A folder that strips out items that do not belong in the current
/// configuration.
/// A folder that strips out items that do not belong in the current configuration.
pub struct StripUnconfigured<'a> {
diag: CfgDiagReal<'a, 'a>,
should_test: bool,
@ -59,6 +39,17 @@ impl<'a> StripUnconfigured<'a> {
}
}
fn configure<T: HasAttrs>(&mut self, node: T) -> Option<T> {
let node = self.process_cfg_attrs(node);
if self.in_cfg(node.attrs()) { Some(node) } else { None }
}
fn process_cfg_attrs<T: HasAttrs>(&mut self, node: T) -> T {
node.map_attrs(|attrs| {
attrs.into_iter().filter_map(|attr| self.process_cfg_attr(attr)).collect()
})
}
fn process_cfg_attr(&mut self, attr: ast::Attribute) -> Option<ast::Attribute> {
if !attr.check_name("cfg_attr") {
return Some(attr);
@ -92,11 +83,8 @@ impl<'a> StripUnconfigured<'a> {
None
}
}
}
impl<'a> CfgFolder for StripUnconfigured<'a> {
// Determine if an item should be translated in the current crate
// configuration based on the item's attributes
// Determine if a node with the given attributes should be included in this configuation.
fn in_cfg(&mut self, attrs: &[ast::Attribute]) -> bool {
attrs.iter().all(|attr| {
// When not compiling with --test we should not compile the #[test] functions
@ -120,12 +108,7 @@ impl<'a> CfgFolder for StripUnconfigured<'a> {
})
}
fn process_attrs<T: HasAttrs>(&mut self, node: T) -> T {
node.map_attrs(|attrs| {
attrs.into_iter().filter_map(|attr| self.process_cfg_attr(attr)).collect()
})
}
// Visit attributes on expression and statements (but not attributes on items in blocks).
fn visit_stmt_or_expr_attrs(&mut self, attrs: &[ast::Attribute]) {
// flag the offending attributes
for attr in attrs.iter() {
@ -133,6 +116,7 @@ impl<'a> CfgFolder for StripUnconfigured<'a> {
}
}
// Visit unremovable (non-optional) expressions -- c.f. `fold_expr` vs `fold_opt_expr`.
fn visit_unremovable_expr(&mut self, expr: &ast::Expr) {
if let Some(attr) = expr.attrs().iter().find(|a| is_cfg(a) || is_test_or_bench(a)) {
let msg = "removing an expression is not supported in this position";
@ -151,7 +135,7 @@ pub fn strip_unconfigured_items(diagnostic: &Handler, krate: ast::Crate, should_
StripUnconfigured::new(config, should_test, diagnostic, feature_gated_cfgs).fold_crate(krate)
}
impl<T: CfgFolder> fold::Folder for T {
impl<'a> fold::Folder for StripUnconfigured<'a> {
fn fold_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod {
ast::ForeignMod {
abi: foreign_mod.abi,
@ -212,7 +196,7 @@ impl<T: CfgFolder> fold::Folder for T {
// NB: This is intentionally not part of the fold_expr() function
// in order for fold_opt_expr() to be able to avoid this check
self.visit_unremovable_expr(&expr);
let expr = self.process_attrs(expr);
let expr = self.process_cfg_attrs(expr);
fold_expr(self, expr)
}
@ -264,7 +248,7 @@ impl<T: CfgFolder> fold::Folder for T {
}
}
fn fold_expr<F: CfgFolder>(folder: &mut F, expr: P<ast::Expr>) -> P<ast::Expr> {
fn fold_expr(folder: &mut StripUnconfigured, expr: P<ast::Expr>) -> P<ast::Expr> {
expr.map(|ast::Expr {id, span, node, attrs}| {
fold::noop_fold_expr(ast::Expr {
id: id,