diff --git a/lib/std/json.zig b/lib/std/json.zig index 41bfb30bc5..1c4cbdf5cb 100644 --- a/lib/std/json.zig +++ b/lib/std/json.zig @@ -1163,11 +1163,12 @@ const ArrayList = std.ArrayList; const StringArrayHashMap = std.StringArrayHashMap; pub const ValueTree = struct { - arena: ArenaAllocator, + arena: *ArenaAllocator, root: Value, pub fn deinit(self: *ValueTree) void { self.arena.deinit(); + self.arena.child_allocator.destroy(self.arena); } }; @@ -1809,8 +1810,12 @@ pub const Parser = struct { pub fn parse(p: *Parser, input: []const u8) !ValueTree { var s = TokenStream.init(input); - var arena = ArenaAllocator.init(p.allocator); + var arena = try p.allocator.create(ArenaAllocator); + errdefer p.allocator.destroy(arena); + + arena.* = ArenaAllocator.init(p.allocator); errdefer arena.deinit(); + const allocator = arena.allocator(); while (try s.next()) |token| { diff --git a/lib/std/json/test.zig b/lib/std/json/test.zig index 70385acfb5..7f87b2fa52 100644 --- a/lib/std/json/test.zig +++ b/lib/std/json/test.zig @@ -2589,6 +2589,24 @@ test "parsing empty string gives appropriate error" { try testing.expectError(error.UnexpectedEndOfJson, testParse(arena_allocator.allocator(), "")); } +test "parse tree should not contain dangling pointers" { + var arena_allocator = std.heap.ArenaAllocator.init(std.testing.allocator); + defer arena_allocator.deinit(); + + var p = json.Parser.init(arena_allocator.allocator(), false); + defer p.deinit(); + + var tree = try p.parse("[]"); + defer tree.deinit(); + + // Allocation should succeed + var i: usize = 0; + while (i < 100) : (i += 1) { + try tree.root.Array.append(std.json.Value{ .Integer = 100 }); + } + try testing.expectEqual(tree.root.Array.items.len, 100); +} + test "integer after float has proper type" { var arena_allocator = std.heap.ArenaAllocator.init(std.testing.allocator); defer arena_allocator.deinit();