Files
ladybird/Libraries/LibJS/SourceRange.h
Andreas Kling eb9432fcb8 LibJS: Preserve source positions in bytecode source maps
Carry full source positions through the Rust bytecode source map so
stack traces and other bytecode-backed source lookups can use them
directly.

This keeps exception-heavy paths from reconstructing line and column
information through SourceCode::range_from_offsets(), which can spend a
lot of time building SourceCode's position cache on first use.

We're trading some space for time here, but I believe it's worth it at
this tag, as this saves ~250ms of main thread time while loading
https://x.com/ on my Linux machine. :^)

Reading the stored Position out of the source map directly also exposed
two things masked by the old range_from_offsets() path: a latent
off-by-one in Lexer::new_at_offset() (its consume() bumped line_column
past the character at offset; only synthesize_binding_pattern() hit it),
and a (1,1) fallback in range_from_offsets() that fired whenever the
queried range reached EOF. Fix the lexer, then rebaseline both the
bytecode dump tests (no more spurious "1:1") and the destructuring AST
tests (binding-pattern identifiers now report their real columns).
2026-04-22 22:34:54 +02:00

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/*
* Copyright (c) 2020, the SerenityOS developers.
* Copyright (c) 2023, Andreas Kling <andreas@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/NonnullRefPtr.h>
#include <AK/RefPtr.h>
#include <AK/StringView.h>
#include <AK/Types.h>
#include <LibJS/Export.h>
#include <LibJS/Position.h>
#include <LibJS/SourceCode.h>
namespace JS {
struct JS_API SourceRange {
[[nodiscard]] bool contains(Position const& position) const { return position.offset <= end.offset && position.offset >= start.offset; }
NonnullRefPtr<SourceCode const> code;
Position start;
Position end;
ByteString filename() const { return code->filename().to_byte_string(); }
};
}