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Proper spans for for loop expansion

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This commit is contained in:
Nick Cameron
2015-05-06 19:17:01 +12:00
parent 4b88e8f63e
commit 0d258516cb
3 changed files with 52 additions and 14 deletions
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51
src/libsyntax/ext/expand.rs
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@@ -19,7 +19,7 @@ use ext::build::AstBuilder;
use attr;
use attr::AttrMetaMethods;
use codemap;
use codemap::{Span, Spanned, ExpnInfo, NameAndSpan, MacroBang, MacroAttribute};
use codemap::{Span, Spanned, ExpnInfo, NameAndSpan, MacroBang, MacroAttribute, CompilerExpansion};
use ext::base::*;
use feature_gate::{self, Features};
use fold;
@@ -34,6 +34,18 @@ use visit::Visitor;
use std_inject;
pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
fn push_compiler_expansion(fld: &mut MacroExpander, span: Span, expansion_desc: &str) {
fld.cx.bt_push(ExpnInfo {
call_site: span,
callee: NameAndSpan {
name: expansion_desc.to_string(),
format: CompilerExpansion,
allow_internal_unstable: true,
span: None,
},
});
}
e.and_then(|ast::Expr {id, node, span}| match node {
// expr_mac should really be expr_ext or something; it's the
// entry-point for all syntax extensions.
@@ -77,6 +89,8 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
// }
// }
push_compiler_expansion(fld, span, "while let expansion");
// `<pat> => <body>`
let pat_arm = {
let body_expr = fld.cx.expr_block(body);
@@ -98,7 +112,9 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
// `[opt_ident]: loop { ... }`
let loop_block = fld.cx.block_expr(match_expr);
let (loop_block, opt_ident) = expand_loop_block(loop_block, opt_ident, fld);
fld.cx.expr(span, ast::ExprLoop(loop_block, opt_ident))
let result = fld.cx.expr(span, ast::ExprLoop(loop_block, opt_ident));
fld.cx.bt_pop();
result
}
// Desugar ExprIfLet
@@ -112,6 +128,8 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
// _ => [<elseopt> | ()]
// }
push_compiler_expansion(fld, span, "if let expansion");
// `<pat> => <body>`
let pat_arm = {
let body_expr = fld.cx.expr_block(body);
@@ -173,13 +191,16 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
ast::MatchSource::IfLetDesugar {
contains_else_clause: contains_else_clause,
}));
fld.fold_expr(match_expr)
let result = fld.fold_expr(match_expr);
fld.cx.bt_pop();
result
}
// Desugar support for ExprIfLet in the ExprIf else position
ast::ExprIf(cond, blk, elseopt) => {
let elseopt = elseopt.map(|els| els.and_then(|els| match els.node {
ast::ExprIfLet(..) => {
push_compiler_expansion(fld, span, "if let expansion");
// wrap the if-let expr in a block
let span = els.span;
let blk = P(ast::Block {
@@ -189,7 +210,9 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
rules: ast::DefaultBlock,
span: span
});
fld.cx.expr_block(blk)
let result = fld.cx.expr_block(blk);
fld.cx.bt_pop();
result
}
_ => P(els)
}));
@@ -221,6 +244,10 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
// result
// }
push_compiler_expansion(fld, span, "for loop expansion");
let span = fld.new_span(span);
// expand <head>
let head = fld.fold_expr(head);
@@ -235,10 +262,11 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
rename_fld.fold_ident(ident)
};
let pat_span = pat.span;
// `:;std::option::Option::Some(<pat>) => <body>`
let pat_span = fld.new_span(pat.span);
// `::std::option::Option::Some(<pat>) => <body>`
let pat_arm = {
let body_expr = fld.cx.expr_block(body);
let pat = noop_fold_pat(pat, fld);
let some_pat = fld.cx.pat_some(pat_span, pat);
fld.cx.arm(pat_span, vec![some_pat], body_expr)
@@ -304,20 +332,25 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
// `{ let result = ...; result }`
let result_ident = token::gensym_ident("result");
fld.cx.expr_block(
let result = fld.cx.expr_block(
fld.cx.block_all(
span,
vec![fld.cx.stmt_let(span, false, result_ident, match_expr)],
Some(fld.cx.expr_ident(span, result_ident))))
Some(fld.cx.expr_ident(span, result_ident))));
fld.cx.bt_pop();
result
}
ast::ExprClosure(capture_clause, fn_decl, block) => {
push_compiler_expansion(fld, span, "closure expansion");
let (rewritten_fn_decl, rewritten_block)
= expand_and_rename_fn_decl_and_block(fn_decl, block, fld);
let new_node = ast::ExprClosure(capture_clause,
rewritten_fn_decl,
rewritten_block);
P(ast::Expr{id:id, node: new_node, span: fld.new_span(span)})
let result = P(ast::Expr{id:id, node: new_node, span: fld.new_span(span)});
fld.cx.bt_pop();
result
}
_ => {