From 73c857415eafc1d0856b6917cada94d8acde41e0 Mon Sep 17 00:00:00 2001 From: John Schmidt Date: Sat, 4 Feb 2023 18:28:36 +0100 Subject: std.json: fix parsing of structs with default value const pointers --- lib/std/json.zig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/std/json.zig') diff --git a/lib/std/json.zig b/lib/std/json.zig index 92afeead90..41bfb30bc5 100644 --- a/lib/std/json.zig +++ b/lib/std/json.zig @@ -1639,7 +1639,7 @@ fn parseInternal( const allocator = options.allocator orelse return error.AllocatorRequired; switch (ptrInfo.size) { .One => { - const r: T = try allocator.create(ptrInfo.child); + const r: *ptrInfo.child = try allocator.create(ptrInfo.child); errdefer allocator.destroy(r); r.* = try parseInternal(ptrInfo.child, token, tokens, options); return r; -- cgit v1.2.3 From b42caff2a20eb34073f6a766f55d27288028165a Mon Sep 17 00:00:00 2001 From: John Schmidt Date: Sat, 4 Feb 2023 18:44:57 +0100 Subject: std.json: avoid dangling pointers in ValueTree Closes https://github.com/ziglang/zig/issues/5229. --- lib/std/json.zig | 9 +++++++-- lib/std/json/test.zig | 18 ++++++++++++++++++ 2 files changed, 25 insertions(+), 2 deletions(-) (limited to 'lib/std/json.zig') 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(); -- cgit v1.2.3 From b1dd4b17d89633c4d26c39952f69d7ff2efb98ce Mon Sep 17 00:00:00 2001 From: John Schmidt Date: Sat, 4 Feb 2023 14:42:42 +0100 Subject: std.json: don't free struct default values Closes https://github.com/ziglang/zig/issues/9509. --- lib/std/json.zig | 32 +++++++++++++++++++++++++++++++- lib/std/json/test.zig | 25 +++++++++++++++++++++++++ 2 files changed, 56 insertions(+), 1 deletion(-) (limited to 'lib/std/json.zig') diff --git a/lib/std/json.zig b/lib/std/json.zig index 1c4cbdf5cb..42c4d98d32 100644 --- a/lib/std/json.zig +++ b/lib/std/json.zig @@ -1745,7 +1745,37 @@ pub fn parseFree(comptime T: type, value: T, options: ParseOptions) void { .Struct => |structInfo| { inline for (structInfo.fields) |field| { if (!field.is_comptime) { - parseFree(field.type, @field(value, field.name), options); + var should_free = true; + if (field.default_value) |default| { + switch (@typeInfo(field.type)) { + // We must not attempt to free pointers to struct default values + .Pointer => |fieldPtrInfo| { + const field_value = @field(value, field.name); + const field_ptr = switch (fieldPtrInfo.size) { + .One => field_value, + .Slice => field_value.ptr, + else => unreachable, // Other pointer types are not parseable + }; + const field_addr = @ptrToInt(field_ptr); + + const casted_default = @ptrCast(*const field.type, @alignCast(@alignOf(field.type), default)).*; + const default_ptr = switch (fieldPtrInfo.size) { + .One => casted_default, + .Slice => casted_default.ptr, + else => unreachable, // Other pointer types are not parseable + }; + const default_addr = @ptrToInt(default_ptr); + + if (field_addr == default_addr) { + should_free = false; + } + }, + else => {}, + } + } + if (should_free) { + parseFree(field.type, @field(value, field.name), options); + } } } }, diff --git a/lib/std/json/test.zig b/lib/std/json/test.zig index 7f87b2fa52..3c9414a59c 100644 --- a/lib/std/json/test.zig +++ b/lib/std/json/test.zig @@ -2246,6 +2246,31 @@ test "parse into struct with default const pointer field" { try testing.expectEqual(T{}, try parse(T, &ts, .{})); } +const test_default_usize: usize = 123; +const test_default_usize_ptr: *align(1) const usize = &test_default_usize; +const test_default_str: []const u8 = "test str"; +const test_default_str_slice: [2][]const u8 = [_][]const u8{ + "test1", + "test2", +}; + +test "freeing parsed structs with pointers to default values" { + const T = struct { + int: *const usize = &test_default_usize, + int_ptr: *allowzero align(1) const usize = test_default_usize_ptr, + str: []const u8 = test_default_str, + str_slice: []const []const u8 = &test_default_str_slice, + }; + + var ts = json.TokenStream.init("{}"); + const options = .{ .allocator = std.heap.page_allocator }; + const parsed = try json.parse(T, &ts, options); + + try testing.expectEqual(T{}, parsed); + + json.parseFree(T, parsed, options); +} + test "parse into struct where destination and source lengths mismatch" { const T = struct { a: [2]u8 }; var ts = TokenStream.init("{\"a\": \"bbb\"}"); -- cgit v1.2.3 From 25d6b8c1f1d5dc532c2bb68057d90751895aea68 Mon Sep 17 00:00:00 2001 From: Leo Constantinides <35425444+leoconst@users.noreply.github.com> Date: Mon, 13 Feb 2023 13:44:34 +0000 Subject: std: support deserialising JSON strings containing escape seqences into sentinel slice --- lib/std/json.zig | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) (limited to 'lib/std/json.zig') diff --git a/lib/std/json.zig b/lib/std/json.zig index 92afeead90..ae8c4678a8 100644 --- a/lib/std/json.zig +++ b/lib/std/json.zig @@ -1678,19 +1678,16 @@ fn parseInternal( if (ptrInfo.child != u8) return error.UnexpectedToken; const source_slice = stringToken.slice(tokens.slice, tokens.i - 1); const len = stringToken.decodedLength(); - const output = try allocator.alloc(u8, len + @boolToInt(ptrInfo.sentinel != null)); + const output = if (ptrInfo.sentinel) |sentinel_ptr| + try allocator.allocSentinel(u8, len, @ptrCast(*const u8, sentinel_ptr).*) + else + try allocator.alloc(u8, len); errdefer allocator.free(output); switch (stringToken.escapes) { .None => mem.copy(u8, output, source_slice), .Some => try unescapeValidString(output, source_slice), } - if (ptrInfo.sentinel) |some| { - const char = @ptrCast(*const u8, some).*; - output[len] = char; - return output[0..len :char]; - } - return output; }, else => return error.UnexpectedToken, @@ -2684,3 +2681,16 @@ test "encodesTo" { try testing.expectEqual(true, encodesTo("😂", "\\ud83d\\ude02")); try testing.expectEqual(true, encodesTo("withąunicode😂", "with\\u0105unicode\\ud83d\\ude02")); } + +test "issue 14600" { + const json = "\"\\n\""; + var token_stream = std.json.TokenStream.init(json); + const options = ParseOptions{ .allocator = std.testing.allocator }; + + // Pre-fix, this line would panic: + const result = try std.json.parse([:0]const u8, &token_stream, options); + defer std.json.parseFree([:0]const u8, result, options); + + // Double-check that we're getting the right result + try testing.expect(mem.eql(u8, result, "\n")); +} -- cgit v1.2.3