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Auto merge of #81294 - pnkfelix:issue-81211-use-ufcs-in-derive-debug, r=oli-obk

Use ufcs in derive(Debug)

Cc #81211.

(Arguably this *is* the fix for it.)
This commit is contained in:
bors 2021-02-03 15:12:19 +00:00
commit 186f7ae5b0
6 changed files with 315 additions and 43 deletions

View file

@ -8,6 +8,10 @@ use rustc_expand::base::{Annotatable, ExtCtxt};
use rustc_span::symbol::{sym, Ident};
use rustc_span::{Span, DUMMY_SP};
fn make_mut_borrow(cx: &mut ExtCtxt<'_>, sp: Span, expr: P<Expr>) -> P<Expr> {
cx.expr(sp, ast::ExprKind::AddrOf(ast::BorrowKind::Ref, ast::Mutability::Mut, expr))
}
pub fn expand_deriving_debug(
cx: &mut ExtCtxt<'_>,
span: Span,
@ -67,11 +71,12 @@ fn show_substructure(cx: &mut ExtCtxt<'_>, span: Span, substr: &Substructure<'_>
let fmt = substr.nonself_args[0].clone();
let mut stmts = Vec::with_capacity(fields.len() + 2);
let fn_path_finish;
match vdata {
ast::VariantData::Tuple(..) | ast::VariantData::Unit(..) => {
// tuple struct/"normal" variant
let expr =
cx.expr_method_call(span, fmt, Ident::new(sym::debug_tuple, span), vec![name]);
let fn_path_debug_tuple = cx.std_path(&[sym::fmt, sym::Formatter, sym::debug_tuple]);
let expr = cx.expr_call_global(span, fn_path_debug_tuple, vec![fmt, name]);
stmts.push(cx.stmt_let(span, true, builder, expr));
for field in fields {
@ -79,22 +84,21 @@ fn show_substructure(cx: &mut ExtCtxt<'_>, span: Span, substr: &Substructure<'_>
let field = cx.expr_addr_of(field.span, field.self_.clone());
let field = cx.expr_addr_of(field.span, field);
let expr = cx.expr_method_call(
span,
builder_expr.clone(),
Ident::new(sym::field, span),
vec![field],
);
let fn_path_field = cx.std_path(&[sym::fmt, sym::DebugTuple, sym::field]);
let builder_recv = make_mut_borrow(cx, span, builder_expr.clone());
let expr = cx.expr_call_global(span, fn_path_field, vec![builder_recv, field]);
// Use `let _ = expr;` to avoid triggering the
// unused_results lint.
stmts.push(stmt_let_underscore(cx, span, expr));
}
fn_path_finish = cx.std_path(&[sym::fmt, sym::DebugTuple, sym::finish]);
}
ast::VariantData::Struct(..) => {
// normal struct/struct variant
let expr =
cx.expr_method_call(span, fmt, Ident::new(sym::debug_struct, span), vec![name]);
let fn_path_debug_struct = cx.std_path(&[sym::fmt, sym::Formatter, sym::debug_struct]);
let expr = cx.expr_call_global(span, fn_path_debug_struct, vec![fmt, name]);
stmts.push(cx.stmt_let(DUMMY_SP, true, builder, expr));
for field in fields {
@ -104,20 +108,20 @@ fn show_substructure(cx: &mut ExtCtxt<'_>, span: Span, substr: &Substructure<'_>
);
// Use double indirection to make sure this works for unsized types
let fn_path_field = cx.std_path(&[sym::fmt, sym::DebugStruct, sym::field]);
let field = cx.expr_addr_of(field.span, field.self_.clone());
let field = cx.expr_addr_of(field.span, field);
let expr = cx.expr_method_call(
span,
builder_expr.clone(),
Ident::new(sym::field, span),
vec![name, field],
);
let builder_recv = make_mut_borrow(cx, span, builder_expr.clone());
let expr =
cx.expr_call_global(span, fn_path_field, vec![builder_recv, name, field]);
stmts.push(stmt_let_underscore(cx, span, expr));
}
fn_path_finish = cx.std_path(&[sym::fmt, sym::DebugStruct, sym::finish]);
}
}
let expr = cx.expr_method_call(span, builder_expr, Ident::new(sym::finish, span), vec![]);
let builder_recv = make_mut_borrow(cx, span, builder_expr);
let expr = cx.expr_call_global(span, fn_path_finish, vec![builder_recv]);
stmts.push(cx.stmt_expr(expr));
let block = cx.block(span, stmts);