Files
bun.sh/src/sourcemap/sourcemap.zig
2025-03-09 03:55:16 -07:00

1588 lines
59 KiB
Zig

const std = @import("std");
const bun = @import("root").bun;
const string = bun.string;
const JSAst = bun.JSAst;
const BabyList = JSAst.BabyList;
const Logger = bun.logger;
const strings = bun.strings;
const MutableString = bun.MutableString;
const StringJoiner = bun.StringJoiner;
const JSPrinter = bun.js_printer;
const URL = bun.URL;
const FileSystem = bun.fs.FileSystem;
const SourceMap = @This();
const debug = bun.Output.scoped(.SourceMap, false);
/// Coordinates in source maps are stored using relative offsets for size
/// reasons. When joining together chunks of a source map that were emitted
/// in parallel for different parts of a file, we need to fix up the first
/// segment of each chunk to be relative to the end of the previous chunk.
pub const SourceMapState = struct {
/// This isn't stored in the source map. It's only used by the bundler to join
/// source map chunks together correctly.
generated_line: i32 = 0,
/// These are stored in the source map in VLQ format.
generated_column: i32 = 0,
source_index: i32 = 0,
original_line: i32 = 0,
original_column: i32 = 0,
};
sources: [][]const u8 = &[_][]u8{},
sources_content: []string,
mapping: Mapping.List = .{},
allocator: std.mem.Allocator,
/// Dictates what parseUrl/parseJSON return.
pub const ParseUrlResultHint = union(enum) {
mappings_only,
/// Source Index to fetch
source_only: u32,
/// In order to fetch source contents, you need to know the
/// index, but you cant know the index until the mappings
/// are loaded. So pass in line+col.
all: struct { line: i32, column: i32 },
};
pub const ParseUrl = struct {
/// Populated when `mappings_only` or `all`.
map: ?*ParsedSourceMap = null,
/// Populated when `all`
/// May be `null` even when requested.
mapping: ?Mapping = null,
/// Populated when `source_only` or `all`
/// May be `null` even when requested, if did not exist in map.
source_contents: ?[]const u8 = null,
};
/// Parses an inline source map url like `data:application/json,....`
/// Currently does not handle non-inline source maps.
///
/// `source` must be in UTF-8 and can be freed after this call.
/// The mappings are owned by the `alloc` allocator.
/// Temporary allocations are made to the `arena` allocator, which
/// should be an arena allocator (caller is assumed to call `deinit`).
pub fn parseUrl(
alloc: std.mem.Allocator,
arena: std.mem.Allocator,
source: []const u8,
hint: ParseUrlResultHint,
) !ParseUrl {
const json_bytes = json_bytes: {
const data_prefix = "data:application/json";
if (bun.strings.hasPrefixComptime(source, data_prefix) and source.len > (data_prefix.len + 1)) try_data_url: {
debug("parse (data url, {d} bytes)", .{source.len});
switch (source[data_prefix.len]) {
';' => {
const encoding = bun.sliceTo(source[data_prefix.len + 1 ..], ',');
if (!bun.strings.eqlComptime(encoding, "base64")) break :try_data_url;
const base64_data = source[data_prefix.len + ";base64,".len ..];
const len = bun.base64.decodeLen(base64_data);
const bytes = arena.alloc(u8, len) catch bun.outOfMemory();
const decoded = bun.base64.decode(bytes, base64_data);
if (!decoded.isSuccessful()) {
return error.InvalidBase64;
}
break :json_bytes bytes[0..decoded.count];
},
',' => break :json_bytes source[data_prefix.len + 1 ..],
else => break :try_data_url,
}
}
return error.UnsupportedFormat;
};
return parseJSON(alloc, arena, json_bytes, hint);
}
/// Parses a JSON source-map
///
/// `source` must be in UTF-8 and can be freed after this call.
/// The mappings are owned by the `alloc` allocator.
/// Temporary allocations are made to the `arena` allocator, which
/// should be an arena allocator (caller is assumed to call `deinit`).
pub fn parseJSON(
alloc: std.mem.Allocator,
arena: std.mem.Allocator,
source: []const u8,
hint: ParseUrlResultHint,
) !ParseUrl {
const json_src = bun.logger.Source.initPathString("sourcemap.json", source);
var log = bun.logger.Log.init(arena);
defer log.deinit();
// the allocator given to the JS parser is not respected for all parts
// of the parse, so we need to remember to reset the ast store
bun.JSAst.Expr.Data.Store.reset();
bun.JSAst.Stmt.Data.Store.reset();
defer {
// the allocator given to the JS parser is not respected for all parts
// of the parse, so we need to remember to reset the ast store
bun.JSAst.Expr.Data.Store.reset();
bun.JSAst.Stmt.Data.Store.reset();
}
debug("parse (JSON, {d} bytes)", .{source.len});
var json = bun.JSON.parse(&json_src, &log, arena, false) catch {
return error.InvalidJSON;
};
if (json.get("version")) |version| {
if (version.data != .e_number or version.data.e_number.value != 3.0) {
return error.UnsupportedVersion;
}
}
const mappings_str = json.get("mappings") orelse {
return error.UnsupportedVersion;
};
if (mappings_str.data != .e_string) {
return error.InvalidSourceMap;
}
const sources_content = switch ((json.get("sourcesContent") orelse return error.InvalidSourceMap).data) {
.e_array => |arr| arr,
else => return error.InvalidSourceMap,
};
const sources_paths = switch ((json.get("sources") orelse return error.InvalidSourceMap).data) {
.e_array => |arr| arr,
else => return error.InvalidSourceMap,
};
if (sources_content.items.len != sources_paths.items.len) {
return error.InvalidSourceMap;
}
var i: usize = 0;
const source_paths_slice = if (hint != .source_only)
alloc.alloc([]const u8, sources_content.items.len) catch bun.outOfMemory()
else
null;
errdefer if (hint != .source_only) {
for (source_paths_slice.?[0..i]) |item| alloc.free(item);
alloc.free(source_paths_slice.?);
};
if (hint != .source_only) for (sources_paths.items.slice()) |item| {
if (item.data != .e_string)
return error.InvalidSourceMap;
source_paths_slice.?[i] = try alloc.dupe(u8, try item.data.e_string.string(alloc));
i += 1;
};
const map = if (hint != .source_only) map: {
const map_data = switch (Mapping.parse(
alloc,
mappings_str.data.e_string.slice(arena),
null,
std.math.maxInt(i32),
std.math.maxInt(i32),
)) {
.success => |x| x,
.fail => |fail| return fail.err,
};
const ptr = ParsedSourceMap.new(map_data);
ptr.external_source_names = source_paths_slice.?;
break :map ptr;
} else null;
errdefer if (map) |m| m.deref();
const mapping, const source_index = switch (hint) {
.source_only => |index| .{ null, index },
.all => |loc| brk: {
const mapping = Mapping.find(map.?.mappings, loc.line, loc.column) orelse
break :brk .{ null, null };
break :brk .{ mapping, std.math.cast(u32, mapping.source_index) };
},
.mappings_only => .{ null, null },
};
const content_slice: ?[]const u8 = if (hint != .mappings_only and
source_index != null and
source_index.? < sources_content.items.len)
content: {
const item = sources_content.items.slice()[source_index.?];
if (item.data != .e_string) {
break :content null;
}
const str = item.data.e_string.string(arena) catch bun.outOfMemory();
if (str.len == 0) {
break :content null;
}
break :content try alloc.dupe(u8, str);
} else null;
return .{
.map = map,
.mapping = mapping,
.source_contents = content_slice,
};
}
pub const Mapping = struct {
generated: LineColumnOffset,
original: LineColumnOffset,
source_index: i32,
pub const List = bun.MultiArrayList(Mapping);
pub const Lookup = struct {
mapping: Mapping,
source_map: ?*ParsedSourceMap = null,
/// Owned by default_allocator always
/// use `getSourceCode` to access this as a Slice
prefetched_source_code: ?[]const u8,
/// This creates a bun.String if the source remap *changes* the source url,
/// which is only possible if the executed file differs from the source file:
///
/// - `bun build --sourcemap`, it is another file on disk
/// - `bun build --compile --sourcemap`, it is an embedded file.
pub fn displaySourceURLIfNeeded(lookup: Lookup, base_filename: []const u8) ?bun.String {
const source_map = lookup.source_map orelse return null;
// See doc comment on `external_source_names`
if (source_map.external_source_names.len == 0)
return null;
if (lookup.mapping.source_index >= source_map.external_source_names.len)
return null;
const name = source_map.external_source_names[@intCast(lookup.mapping.source_index)];
if (source_map.is_standalone_module_graph) {
return bun.String.createUTF8(name);
}
if (std.fs.path.isAbsolute(base_filename)) {
const dir = bun.path.dirname(base_filename, .auto);
return bun.String.createUTF8(bun.path.joinAbs(dir, .auto, name));
}
return bun.String.init(name);
}
/// Only valid if `lookup.source_map.isExternal()`
/// This has the possibility of invoking a call to the filesystem.
///
/// This data is freed after printed on the assumption that printing
/// errors to the console are rare (this isnt used for error.stack)
pub fn getSourceCode(lookup: Lookup, base_filename: []const u8) ?bun.JSC.ZigString.Slice {
const bytes = bytes: {
if (lookup.prefetched_source_code) |code| {
break :bytes code;
}
const source_map = lookup.source_map orelse return null;
assert(source_map.isExternal());
const provider = source_map.underlying_provider.provider() orelse
return null;
const index = lookup.mapping.source_index;
// Standalone module graph source maps are stored (in memory) compressed.
// They are decompressed on demand.
if (source_map.is_standalone_module_graph) {
const serialized = source_map.standaloneModuleGraphData();
if (index >= source_map.external_source_names.len)
return null;
const code = serialized.sourceFileContents(@intCast(index));
return bun.JSC.ZigString.Slice.fromUTF8NeverFree(code orelse return null);
}
if (provider.getSourceMap(
base_filename,
source_map.underlying_provider.load_hint,
.{ .source_only = @intCast(index) },
)) |parsed|
if (parsed.source_contents) |contents|
break :bytes contents;
if (index >= source_map.external_source_names.len)
return null;
const name = source_map.external_source_names[@intCast(index)];
var buf: bun.PathBuffer = undefined;
const normalized = bun.path.joinAbsStringBufZ(
bun.path.dirname(base_filename, .auto),
&buf,
&.{name},
.loose,
);
switch (bun.sys.File.readFrom(
std.fs.cwd(),
normalized,
bun.default_allocator,
)) {
.result => |r| break :bytes r,
.err => return null,
}
};
return bun.JSC.ZigString.Slice.init(bun.default_allocator, bytes);
}
};
pub inline fn generatedLine(mapping: Mapping) i32 {
return mapping.generated.lines;
}
pub inline fn generatedColumn(mapping: Mapping) i32 {
return mapping.generated.columns;
}
pub inline fn sourceIndex(mapping: Mapping) i32 {
return mapping.source_index;
}
pub inline fn originalLine(mapping: Mapping) i32 {
return mapping.original.lines;
}
pub inline fn originalColumn(mapping: Mapping) i32 {
return mapping.original.columns;
}
pub fn find(mappings: Mapping.List, line: i32, column: i32) ?Mapping {
if (findIndex(mappings, line, column)) |i| {
return mappings.get(i);
}
return null;
}
pub fn findIndex(mappings: Mapping.List, line: i32, column: i32) ?usize {
const generated = mappings.items(.generated);
var count = generated.len;
var index: usize = 0;
while (count > 0) {
const step = count / 2;
const i: usize = index + step;
const mapping = generated[i];
if (mapping.lines < line or (mapping.lines == line and mapping.columns <= column)) {
index = i + 1;
count -|= step + 1;
} else {
count = step;
}
}
if (index > 0) {
if (generated[index - 1].lines == line) {
return index - 1;
}
}
return null;
}
pub fn parse(
allocator: std.mem.Allocator,
bytes: []const u8,
estimated_mapping_count: ?usize,
sources_count: i32,
input_line_count: usize,
) ParseResult {
debug("parse mappings ({d} bytes)", .{bytes.len});
var mapping = Mapping.List{};
if (estimated_mapping_count) |count| {
mapping.ensureTotalCapacity(allocator, count) catch unreachable;
}
var generated = LineColumnOffset{ .lines = 0, .columns = 0 };
var original = LineColumnOffset{ .lines = 0, .columns = 0 };
var source_index: i32 = 0;
var needs_sort = false;
var remain = bytes;
while (remain.len > 0) {
if (remain[0] == ';') {
generated.columns = 0;
while (strings.hasPrefixComptime(
remain,
comptime [_]u8{';'} ** (@sizeOf(usize) / 2),
)) {
generated.lines += (@sizeOf(usize) / 2);
remain = remain[@sizeOf(usize) / 2 ..];
}
while (remain.len > 0 and remain[0] == ';') {
generated.lines += 1;
remain = remain[1..];
}
if (remain.len == 0) {
break;
}
}
// Read the generated column
const generated_column_delta = decodeVLQ(remain, 0);
if (generated_column_delta.start == 0) {
return .{
.fail = .{
.msg = "Missing generated column value",
.err = error.MissingGeneratedColumnValue,
.value = generated.columns,
.loc = .{ .start = @as(i32, @intCast(bytes.len - remain.len)) },
},
};
}
needs_sort = needs_sort or generated_column_delta.value < 0;
generated.columns += generated_column_delta.value;
if (generated.columns < 0) {
return .{
.fail = .{
.msg = "Invalid generated column value",
.err = error.InvalidGeneratedColumnValue,
.value = generated.columns,
.loc = .{ .start = @as(i32, @intCast(bytes.len - remain.len)) },
},
};
}
remain = remain[generated_column_delta.start..];
// According to the specification, it's valid for a mapping to have 1,
// 4, or 5 variable-length fields. Having one field means there's no
// original location information, which is pretty useless. Just ignore
// those entries.
if (remain.len == 0)
break;
switch (remain[0]) {
',' => {
remain = remain[1..];
continue;
},
';' => {
continue;
},
else => {},
}
// Read the original source
const source_index_delta = decodeVLQ(remain, 0);
if (source_index_delta.start == 0) {
return .{
.fail = .{
.msg = "Invalid source index delta",
.err = error.InvalidSourceIndexDelta,
.loc = .{ .start = @as(i32, @intCast(bytes.len - remain.len)) },
},
};
}
source_index += source_index_delta.value;
if (source_index < 0 or source_index > sources_count) {
return .{
.fail = .{
.msg = "Invalid source index value",
.err = error.InvalidSourceIndexValue,
.value = source_index,
.loc = .{ .start = @as(i32, @intCast(bytes.len - remain.len)) },
},
};
}
remain = remain[source_index_delta.start..];
// Read the original line
const original_line_delta = decodeVLQ(remain, 0);
if (original_line_delta.start == 0) {
return .{
.fail = .{
.msg = "Missing original line",
.err = error.MissingOriginalLine,
.loc = .{ .start = @as(i32, @intCast(bytes.len - remain.len)) },
},
};
}
original.lines += original_line_delta.value;
if (original.lines < 0) {
return .{
.fail = .{
.msg = "Invalid original line value",
.err = error.InvalidOriginalLineValue,
.value = original.lines,
.loc = .{ .start = @as(i32, @intCast(bytes.len - remain.len)) },
},
};
}
remain = remain[original_line_delta.start..];
// Read the original column
const original_column_delta = decodeVLQ(remain, 0);
if (original_column_delta.start == 0) {
return .{
.fail = .{
.msg = "Missing original column value",
.err = error.MissingOriginalColumnValue,
.value = original.columns,
.loc = .{ .start = @as(i32, @intCast(bytes.len - remain.len)) },
},
};
}
original.columns += original_column_delta.value;
if (original.columns < 0) {
return .{
.fail = .{
.msg = "Invalid original column value",
.err = error.InvalidOriginalColumnValue,
.value = original.columns,
.loc = .{ .start = @as(i32, @intCast(bytes.len - remain.len)) },
},
};
}
remain = remain[original_column_delta.start..];
if (remain.len > 0) {
switch (remain[0]) {
',' => {
remain = remain[1..];
},
';' => {},
else => |c| {
return .{
.fail = .{
.msg = "Invalid character after mapping",
.err = error.InvalidSourceMap,
.value = @as(i32, @intCast(c)),
.loc = .{ .start = @as(i32, @intCast(bytes.len - remain.len)) },
},
};
},
}
}
mapping.append(allocator, .{
.generated = generated,
.original = original,
.source_index = source_index,
}) catch bun.outOfMemory();
}
return .{ .success = .{
.mappings = mapping,
.input_line_count = input_line_count,
} };
}
};
pub const ParseResult = union(enum) {
fail: struct {
loc: Logger.Loc,
err: anyerror,
value: i32 = 0,
msg: []const u8 = "",
pub fn toData(this: @This(), path: []const u8) Logger.Data {
return Logger.Data{
.location = Logger.Location{
.file = path,
.offset = this.loc.toUsize(),
// TODO: populate correct line and column information
.line = -1,
.column = -1,
},
.text = this.msg,
};
}
},
success: ParsedSourceMap,
};
pub const ParsedSourceMap = struct {
input_line_count: usize = 0,
mappings: Mapping.List = .{},
/// If this is empty, this implies that the source code is a single file
/// transpiled on-demand. If there are items, then it means this is a file
/// loaded without transpilation but with external sources. This array
/// maps `source_index` to the correct filename.
external_source_names: []const []const u8 = &.{},
/// In order to load source contents from a source-map after the fact,
/// a handle to the underlying source provider is stored. Within this pointer,
/// a flag is stored if it is known to be an inline or external source map.
///
/// Source contents are large, we don't preserve them in memory. This has
/// the downside of repeatedly re-decoding sourcemaps if multiple errors
/// are emitted (specifically with Bun.inspect / unhandled; the ones that
/// rely on source contents)
underlying_provider: SourceContentPtr = .none,
ref_count: std.atomic.Value(u32) = .init(1),
is_standalone_module_graph: bool = false,
pub usingnamespace bun.NewThreadSafeRefCounted(ParsedSourceMap, deinitFn, null);
const SourceContentPtr = packed struct(u64) {
load_hint: SourceMapLoadHint,
data: u62,
pub const none: SourceContentPtr = .{ .load_hint = .none, .data = 0 };
fn fromProvider(p: *SourceProviderMap) SourceContentPtr {
return .{ .load_hint = .none, .data = @intCast(@intFromPtr(p)) };
}
pub fn provider(sc: SourceContentPtr) ?*SourceProviderMap {
return @ptrFromInt(sc.data);
}
};
pub fn isExternal(psm: *ParsedSourceMap) bool {
return psm.external_source_names.len != 0;
}
fn deinitFn(this: *ParsedSourceMap) void {
this.deinitWithAllocator(bun.default_allocator);
}
fn deinitWithAllocator(this: *ParsedSourceMap, allocator: std.mem.Allocator) void {
this.mappings.deinit(allocator);
if (this.external_source_names.len > 0) {
for (this.external_source_names) |name|
allocator.free(name);
allocator.free(this.external_source_names);
}
this.destroy();
}
fn standaloneModuleGraphData(this: *ParsedSourceMap) *bun.StandaloneModuleGraph.SerializedSourceMap.Loaded {
bun.assert(this.is_standalone_module_graph);
return @ptrFromInt(this.underlying_provider.data);
}
pub fn writeVLQs(map: ParsedSourceMap, writer: anytype) !void {
var last_col: i32 = 0;
var last_src: i32 = 0;
var last_ol: i32 = 0;
var last_oc: i32 = 0;
var current_line: i32 = 0;
for (
map.mappings.items(.generated),
map.mappings.items(.original),
map.mappings.items(.source_index),
0..,
) |gen, orig, source_index, i| {
if (current_line != gen.lines) {
assert(gen.lines > current_line);
const inc = gen.lines - current_line;
try writer.writeByteNTimes(';', @intCast(inc));
current_line = gen.lines;
last_col = 0;
} else if (i != 0) {
try writer.writeByte(',');
}
try VLQ.encode(gen.columns - last_col).writeTo(writer);
last_col = gen.columns;
try VLQ.encode(source_index - last_src).writeTo(writer);
last_src = source_index;
try VLQ.encode(orig.lines - last_ol).writeTo(writer);
last_ol = orig.lines;
try VLQ.encode(orig.columns - last_oc).writeTo(writer);
last_oc = orig.columns;
}
}
pub fn formatVLQs(map: *const ParsedSourceMap) std.fmt.Formatter(formatVLQsImpl) {
return .{ .data = map };
}
fn formatVLQsImpl(map: *const ParsedSourceMap, comptime _: []const u8, _: std.fmt.FormatOptions, w: anytype) !void {
try map.writeVLQs(w);
}
};
/// For some sourcemap loading code, this enum is used as a hint if it should
/// bother loading source code into memory. Most uses of source maps only care
/// about filenames and source mappings, and we should avoid loading contents
/// whenever possible.
pub const SourceContentHandling = enum(u1) {
no_source_contents,
source_contents,
};
/// For some sourcemap loading code, this enum is used as a hint if we already
/// know if the sourcemap is located on disk or inline in the source code.
pub const SourceMapLoadHint = enum(u2) {
none,
is_inline_map,
is_external_map,
};
/// This is a pointer to a ZigSourceProvider that may or may not have a `//# sourceMappingURL` comment
/// when we want to lookup this data, we will then resolve it to a ParsedSourceMap if it does.
///
/// This is used for files that were pre-bundled with `bun build --target=bun --sourcemap`
pub const SourceProviderMap = opaque {
extern fn ZigSourceProvider__getSourceSlice(*SourceProviderMap) bun.String;
fn findSourceMappingURL(comptime T: type, source: []const T, alloc: std.mem.Allocator) ?bun.JSC.ZigString.Slice {
const needle = comptime bun.strings.literal(T, "\n//# sourceMappingURL=");
const found = bun.strings.indexOfT(T, source, needle) orelse return null;
const end = std.mem.indexOfScalarPos(T, source, found + needle.len, '\n') orelse source.len;
const url = std.mem.trimRight(T, source[found + needle.len .. end], &.{ ' ', '\r' });
return switch (T) {
u8 => bun.JSC.ZigString.Slice.fromUTF8NeverFree(url),
u16 => bun.JSC.ZigString.Slice.init(
alloc,
bun.strings.toUTF8Alloc(alloc, url) catch bun.outOfMemory(),
),
else => @compileError("Not Supported"),
};
}
/// The last two arguments to this specify loading hints
pub fn getSourceMap(
provider: *SourceProviderMap,
source_filename: []const u8,
load_hint: SourceMapLoadHint,
result: ParseUrlResultHint,
) ?SourceMap.ParseUrl {
var sfb = std.heap.stackFallback(65536, bun.default_allocator);
var arena = bun.ArenaAllocator.init(sfb.get());
defer arena.deinit();
const allocator = arena.allocator();
const new_load_hint: SourceMapLoadHint, const parsed = parsed: {
var inline_err: ?anyerror = null;
// try to get an inline source map
if (load_hint != .is_external_map) try_inline: {
const source = ZigSourceProvider__getSourceSlice(provider);
defer source.deref();
bun.assert(source.tag == .ZigString);
const found_url = (if (source.is8Bit())
findSourceMappingURL(u8, source.latin1(), allocator)
else
findSourceMappingURL(u16, source.utf16(), allocator)) orelse
break :try_inline;
defer found_url.deinit();
break :parsed .{
.is_inline_map,
parseUrl(
bun.default_allocator,
allocator,
found_url.slice(),
result,
) catch |err| {
inline_err = err;
break :try_inline;
},
};
}
// try to load a .map file
if (load_hint != .is_inline_map) try_external: {
var load_path_buf: bun.PathBuffer = undefined;
if (source_filename.len + 4 > load_path_buf.len)
break :try_external;
@memcpy(load_path_buf[0..source_filename.len], source_filename);
@memcpy(load_path_buf[source_filename.len..][0..4], ".map");
const load_path = load_path_buf[0 .. source_filename.len + 4];
const data = switch (bun.sys.File.readFrom(std.fs.cwd(), load_path, allocator)) {
.err => break :try_external,
.result => |data| data,
};
break :parsed .{
.is_external_map,
parseJSON(
bun.default_allocator,
allocator,
data,
result,
) catch |err| {
// Print warning even if this came from non-visible code like
// calling `error.stack`. This message is only printed if
// the sourcemap has been found but is invalid, such as being
// invalid JSON text or corrupt mappings.
bun.Output.warn("Could not decode sourcemap in '{s}': {s}", .{
source_filename,
@errorName(err),
}); // Disable the "try using --sourcemap=external" hint
bun.JSC.SavedSourceMap.MissingSourceMapNoteInfo.seen_invalid = true;
return null;
},
};
}
if (inline_err) |err| {
bun.Output.warn("Could not decode sourcemap in '{s}': {s}", .{
source_filename,
@errorName(err),
});
// Disable the "try using --sourcemap=external" hint
bun.JSC.SavedSourceMap.MissingSourceMapNoteInfo.seen_invalid = true;
return null;
}
return null;
};
if (parsed.map) |ptr| {
ptr.underlying_provider = ParsedSourceMap.SourceContentPtr.fromProvider(provider);
ptr.underlying_provider.load_hint = new_load_hint;
}
return parsed;
}
};
pub const LineColumnOffset = struct {
lines: i32 = 0,
columns: i32 = 0,
pub const Optional = union(enum) {
null: void,
value: LineColumnOffset,
pub fn advance(this: *Optional, input: []const u8) void {
switch (this.*) {
.null => {},
.value => |*v| v.advance(input),
}
}
pub fn reset(this: *Optional) void {
switch (this.*) {
.null => {},
.value => this.* = .{ .value = .{} },
}
}
};
pub fn add(this: *LineColumnOffset, b: LineColumnOffset) void {
if (b.lines == 0) {
this.columns += b.columns;
} else {
this.lines += b.lines;
this.columns = b.columns;
}
}
pub fn advance(this_ptr: *LineColumnOffset, input: []const u8) void {
// Instead of mutating `this_ptr` directly, copy the state to the stack and do
// all the work here, then move it back to the input pointer. When sourcemaps
// are enabled, this function is extremely hot.
var this = this_ptr.*;
defer this_ptr.* = this;
var offset: u32 = 0;
while (strings.indexOfNewlineOrNonASCII(input, offset)) |i| {
assert(i >= offset);
assert(i < input.len);
var iter = strings.CodepointIterator.initOffset(input, i);
var cursor = strings.CodepointIterator.Cursor{ .i = @as(u32, @truncate(iter.i)) };
_ = iter.next(&cursor);
// Given a null byte, cursor.width becomes 0
// This can lead to integer overflow, crashes, or hangs.
// https://github.com/oven-sh/bun/issues/10624
if (cursor.width == 0) {
this.columns += 1;
offset = i + 1;
continue;
}
offset = i + cursor.width;
switch (cursor.c) {
'\r', '\n', 0x2028, 0x2029 => {
// Handle Windows-specific "\r\n" newlines
if (cursor.c == '\r' and input.len > i + 1 and input[i + 1] == '\n') {
this.columns += 1;
continue;
}
this.lines += 1;
this.columns = 0;
},
else => |c| {
// Mozilla's "source-map" library counts columns using UTF-16 code units
this.columns += switch (c) {
0...0xFFFF => 1,
else => 2,
};
},
}
}
const remain = input[offset..];
if (bun.Environment.allow_assert) {
assert(bun.strings.isAllASCII(remain));
assert(!bun.strings.containsChar(remain, '\n'));
assert(!bun.strings.containsChar(remain, '\r'));
}
this.columns += @intCast(remain.len);
}
pub fn comesBefore(a: LineColumnOffset, b: LineColumnOffset) bool {
return a.lines < b.lines or (a.lines == b.lines and a.columns < b.columns);
}
pub fn cmp(_: void, a: LineColumnOffset, b: LineColumnOffset) std.math.Order {
if (a.lines != b.lines) {
return std.math.order(a.lines, b.lines);
}
return std.math.order(a.columns, b.columns);
}
};
pub const SourceContent = struct {
value: []const u16 = &[_]u16{},
quoted: []const u8 = &[_]u8{},
};
pub fn find(
this: *const SourceMap,
line: i32,
column: i32,
) ?Mapping {
return Mapping.find(this.mapping, line, column);
}
pub const SourceMapShifts = struct {
before: LineColumnOffset,
after: LineColumnOffset,
};
pub const SourceMapPieces = struct {
prefix: std.ArrayList(u8),
mappings: std.ArrayList(u8),
suffix: std.ArrayList(u8),
pub fn init(allocator: std.mem.Allocator) SourceMapPieces {
return .{
.prefix = std.ArrayList(u8).init(allocator),
.mappings = std.ArrayList(u8).init(allocator),
.suffix = std.ArrayList(u8).init(allocator),
};
}
pub fn hasContent(this: *SourceMapPieces) bool {
return (this.prefix.items.len + this.mappings.items.len + this.suffix.items.len) > 0;
}
pub fn finalize(this: *SourceMapPieces, allocator: std.mem.Allocator, _shifts: []SourceMapShifts) ![]const u8 {
var shifts = _shifts;
var start_of_run: usize = 0;
var current: usize = 0;
var generated = LineColumnOffset{};
var prev_shift_column_delta: i32 = 0;
// the joiner's node allocator contains string join nodes as well as some vlq encodings
// it doesnt contain json payloads or source code, so 16kb is probably going to cover
// most applications.
var sfb = std.heap.stackFallback(16384, bun.default_allocator);
var j = StringJoiner{ .allocator = sfb.get() };
j.pushStatic(this.prefix.items);
const mappings = this.mappings.items;
while (current < mappings.len) {
if (mappings[current] == ';') {
generated.lines += 1;
generated.columns = 0;
prev_shift_column_delta = 0;
current += 1;
continue;
}
const potential_end_of_run = current;
const decode_result = decodeVLQ(mappings, current);
generated.columns += decode_result.value;
current = decode_result.start;
const potential_start_of_run = current;
current = decodeVLQAssumeValid(mappings, current).start;
current = decodeVLQAssumeValid(mappings, current).start;
current = decodeVLQAssumeValid(mappings, current).start;
if (current < mappings.len) {
const c = mappings[current];
if (c != ',' and c != ';') {
current = decodeVLQAssumeValid(mappings, current).start;
}
}
if (current < mappings.len and mappings[current] == ',') {
current += 1;
}
var did_cross_boundary = false;
if (shifts.len > 1 and shifts[1].before.comesBefore(generated)) {
shifts = shifts[1..];
did_cross_boundary = true;
}
if (!did_cross_boundary) {
continue;
}
const shift = shifts[0];
if (shift.after.lines != generated.lines) {
continue;
}
j.pushStatic(mappings[start_of_run..potential_end_of_run]);
assert(shift.before.lines == shift.after.lines);
const shift_column_delta = shift.after.columns - shift.before.columns;
const vlq_value = decode_result.value + shift_column_delta - prev_shift_column_delta;
const encode = VLQ.encode(vlq_value);
j.pushCloned(encode.slice());
prev_shift_column_delta = shift_column_delta;
start_of_run = potential_start_of_run;
}
j.pushStatic(mappings[start_of_run..]);
const str = try j.doneWithEnd(allocator, this.suffix.items);
bun.assert(str[0] == '{'); // invalid json
return str;
}
};
// -- comment from esbuild --
// Source map chunks are computed in parallel for speed. Each chunk is relative
// to the zero state instead of being relative to the end state of the previous
// chunk, since it's impossible to know the end state of the previous chunk in
// a parallel computation.
//
// After all chunks are computed, they are joined together in a second pass.
// This rewrites the first mapping in each chunk to be relative to the end
// state of the previous chunk.
pub fn appendSourceMapChunk(j: *StringJoiner, allocator: std.mem.Allocator, prev_end_state_: SourceMapState, start_state_: SourceMapState, source_map_: bun.string) !void {
var prev_end_state = prev_end_state_;
var start_state = start_state_;
// Handle line breaks in between this mapping and the previous one
if (start_state.generated_line != 0) {
j.push(try strings.repeatingAlloc(allocator, @intCast(start_state.generated_line), ';'), allocator);
prev_end_state.generated_column = 0;
}
// Skip past any leading semicolons, which indicate line breaks
var source_map = source_map_;
if (strings.indexOfNotChar(source_map, ';')) |semicolons| {
if (semicolons > 0) {
j.pushStatic(source_map[0..semicolons]);
source_map = source_map[semicolons..];
prev_end_state.generated_column = 0;
start_state.generated_column = 0;
}
}
// Strip off the first mapping from the buffer. The first mapping should be
// for the start of the original file (the printer always generates one for
// the start of the file).
var i: usize = 0;
const generated_column = decodeVLQAssumeValid(source_map, i);
i = generated_column.start;
const source_index = decodeVLQAssumeValid(source_map, i);
i = source_index.start;
const original_line = decodeVLQAssumeValid(source_map, i);
i = original_line.start;
const original_column = decodeVLQAssumeValid(source_map, i);
i = original_column.start;
source_map = source_map[i..];
// Rewrite the first mapping to be relative to the end state of the previous
// chunk. We now know what the end state is because we're in the second pass
// where all chunks have already been generated.
start_state.source_index += source_index.value;
start_state.generated_column += generated_column.value;
start_state.original_line += original_line.value;
start_state.original_column += original_column.value;
j.push(
appendMappingToBuffer(
MutableString.initEmpty(allocator),
j.lastByte(),
prev_end_state,
start_state,
).list.items,
allocator,
);
// Then append everything after that without modification.
j.pushStatic(source_map);
}
pub fn appendSourceMappingURLRemote(
origin: URL,
source: Logger.Source,
asset_prefix_path: []const u8,
comptime Writer: type,
writer: Writer,
) !void {
try writer.writeAll("\n//# sourceMappingURL=");
try writer.writeAll(strings.withoutTrailingSlash(origin.href));
if (asset_prefix_path.len > 0)
try writer.writeAll(asset_prefix_path);
if (source.path.pretty.len > 0 and source.path.pretty[0] != '/') {
try writer.writeAll("/");
}
try writer.writeAll(source.path.pretty);
try writer.writeAll(".map");
}
/// This function is extremely hot.
pub fn appendMappingToBuffer(buffer_: MutableString, last_byte: u8, prev_state: SourceMapState, current_state: SourceMapState) MutableString {
var buffer = buffer_;
const needs_comma = last_byte != 0 and last_byte != ';' and last_byte != '"';
const vlqs = [_]VLQ{
// Record the generated column (the line is recorded using ';' elsewhere)
.encode(current_state.generated_column -| prev_state.generated_column),
// Record the generated source
.encode(current_state.source_index -| prev_state.source_index),
// Record the original line
.encode(current_state.original_line -| prev_state.original_line),
// Record the original column
.encode(current_state.original_column -| prev_state.original_column),
};
// Count exactly how many bytes we need to write
const total_len = @as(usize, vlqs[0].len) +
@as(usize, vlqs[1].len) +
@as(usize, vlqs[2].len) +
@as(usize, vlqs[3].len);
// Instead of updating .len 5 times, we only need to update it once.
var writable = buffer.writableNBytes(total_len + @as(usize, @intFromBool(needs_comma))) catch unreachable;
// Put commas in between mappings
if (needs_comma) {
writable[0] = ',';
writable = writable[1..];
}
inline for (&vlqs) |item| {
@memcpy(writable[0..item.len], item.slice());
writable = writable[item.len..];
}
return buffer;
}
pub const Chunk = struct {
buffer: MutableString,
mappings_count: usize = 0,
/// This end state will be used to rewrite the start of the following source
/// map chunk so that the delta-encoded VLQ numbers are preserved.
end_state: SourceMapState = .{},
/// There probably isn't a source mapping at the end of the file (nor should
/// there be) but if we're appending another source map chunk after this one,
/// we'll need to know how many characters were in the last line we generated.
final_generated_column: i32 = 0,
/// ignore empty chunks
should_ignore: bool = true,
pub const empty: Chunk = .{
.buffer = MutableString.initEmpty(bun.default_allocator),
.mappings_count = 0,
.end_state = .{},
.final_generated_column = 0,
.should_ignore = true,
};
pub fn printSourceMapContents(
chunk: Chunk,
source: *const Logger.Source,
mutable: MutableString,
include_sources_contents: bool,
comptime ascii_only: bool,
) !MutableString {
return printSourceMapContentsAtOffset(
chunk,
source,
mutable,
include_sources_contents,
0,
ascii_only,
);
}
pub fn printSourceMapContentsAtOffset(
chunk: Chunk,
source: *const Logger.Source,
mutable: MutableString,
include_sources_contents: bool,
offset: usize,
comptime ascii_only: bool,
) !MutableString {
var output = mutable;
// attempt to pre-allocate
var filename_buf: bun.PathBuffer = undefined;
var filename = source.path.text;
if (strings.hasPrefix(source.path.text, FileSystem.instance.top_level_dir)) {
filename = filename[FileSystem.instance.top_level_dir.len - 1 ..];
} else if (filename.len > 0 and filename[0] != '/') {
filename_buf[0] = '/';
@memcpy(filename_buf[1..][0..filename.len], filename);
filename = filename_buf[0 .. filename.len + 1];
}
output.growIfNeeded(
filename.len + 2 + (source.contents.len * @as(usize, @intFromBool(include_sources_contents))) + (chunk.buffer.list.items.len - offset) + 32 + 39 + 29 + 22 + 20,
) catch unreachable;
try output.append("{\n \"version\":3,\n \"sources\": [");
output = try JSPrinter.quoteForJSON(filename, output, ascii_only);
if (include_sources_contents) {
try output.append("],\n \"sourcesContent\": [");
output = try JSPrinter.quoteForJSON(source.contents, output, ascii_only);
}
try output.append("],\n \"mappings\": ");
output = try JSPrinter.quoteForJSON(chunk.buffer.list.items[offset..], output, ascii_only);
try output.append(", \"names\": []\n}");
return output;
}
// TODO: remove the indirection by having generic functions for SourceMapFormat and NewBuilder. Source maps are always VLQ
pub fn SourceMapFormat(comptime Type: type) type {
return struct {
ctx: Type,
const Format = @This();
pub fn init(allocator: std.mem.Allocator, prepend_count: bool) Format {
return .{ .ctx = Type.init(allocator, prepend_count) };
}
pub inline fn appendLineSeparator(this: *Format) anyerror!void {
try this.ctx.appendLineSeparator();
}
pub inline fn append(this: *Format, current_state: SourceMapState, prev_state: SourceMapState) anyerror!void {
try this.ctx.append(current_state, prev_state);
}
pub inline fn shouldIgnore(this: Format) bool {
return this.ctx.shouldIgnore();
}
pub inline fn getBuffer(this: Format) MutableString {
return this.ctx.getBuffer();
}
pub inline fn getCount(this: Format) usize {
return this.ctx.getCount();
}
};
}
pub const VLQSourceMap = struct {
data: MutableString,
count: usize = 0,
offset: usize = 0,
approximate_input_line_count: usize = 0,
pub const Format = SourceMapFormat(VLQSourceMap);
pub fn init(allocator: std.mem.Allocator, prepend_count: bool) VLQSourceMap {
var map = VLQSourceMap{
.data = MutableString.initEmpty(allocator),
};
// For bun.js, we store the number of mappings and how many bytes the final list is at the beginning of the array
if (prepend_count) {
map.offset = 24;
map.data.append(&([_]u8{0} ** 24)) catch unreachable;
}
return map;
}
pub fn appendLineSeparator(this: *VLQSourceMap) anyerror!void {
try this.data.appendChar(';');
}
pub fn append(this: *VLQSourceMap, current_state: SourceMapState, prev_state: SourceMapState) anyerror!void {
const last_byte: u8 = if (this.data.list.items.len > this.offset)
this.data.list.items[this.data.list.items.len - 1]
else
0;
this.data = appendMappingToBuffer(this.data, last_byte, prev_state, current_state);
this.count += 1;
}
pub fn shouldIgnore(this: VLQSourceMap) bool {
return this.count == 0;
}
pub fn getBuffer(this: VLQSourceMap) MutableString {
return this.data;
}
pub fn getCount(this: VLQSourceMap) usize {
return this.count;
}
};
pub fn NewBuilder(comptime SourceMapFormatType: type) type {
return struct {
const ThisBuilder = @This();
input_source_map: ?*SourceMap = null,
source_map: SourceMapper,
line_offset_tables: LineOffsetTable.List = .{},
prev_state: SourceMapState = SourceMapState{},
last_generated_update: u32 = 0,
generated_column: i32 = 0,
prev_loc: Logger.Loc = Logger.Loc.Empty,
has_prev_state: bool = false,
line_offset_table_byte_offset_list: []const u32 = &.{},
// This is a workaround for a bug in the popular "source-map" library:
// https://github.com/mozilla/source-map/issues/261. The library will
// sometimes return null when querying a source map unless every line
// starts with a mapping at column zero.
//
// The workaround is to replicate the previous mapping if a line ends
// up not starting with a mapping. This is done lazily because we want
// to avoid replicating the previous mapping if we don't need to.
line_starts_with_mapping: bool = false,
cover_lines_without_mappings: bool = false,
approximate_input_line_count: usize = 0,
/// When generating sourcemappings for bun, we store a count of how many mappings there were
prepend_count: bool = false,
pub const SourceMapper = SourceMapFormat(SourceMapFormatType);
pub noinline fn generateChunk(b: *ThisBuilder, output: []const u8) Chunk {
b.updateGeneratedLineAndColumn(output);
if (b.prepend_count) {
b.source_map.getBuffer().list.items[0..8].* = @as([8]u8, @bitCast(b.source_map.getBuffer().list.items.len));
b.source_map.getBuffer().list.items[8..16].* = @as([8]u8, @bitCast(b.source_map.getCount()));
b.source_map.getBuffer().list.items[16..24].* = @as([8]u8, @bitCast(b.approximate_input_line_count));
}
return Chunk{
.buffer = b.source_map.getBuffer(),
.mappings_count = b.source_map.getCount(),
.end_state = b.prev_state,
.final_generated_column = b.generated_column,
.should_ignore = b.source_map.shouldIgnore(),
};
}
// Scan over the printed text since the last source mapping and update the
// generated line and column numbers
pub fn updateGeneratedLineAndColumn(b: *ThisBuilder, output: []const u8) void {
const slice = output[b.last_generated_update..];
var needs_mapping = b.cover_lines_without_mappings and !b.line_starts_with_mapping and b.has_prev_state;
var i: usize = 0;
const n = @as(usize, @intCast(slice.len));
var c: i32 = 0;
while (i < n) {
const len = strings.wtf8ByteSequenceLengthWithInvalid(slice[i]);
c = strings.decodeWTF8RuneT(slice[i..].ptr[0..4], len, i32, strings.unicode_replacement);
i += @as(usize, len);
switch (c) {
14...127 => {
if (strings.indexOfNewlineOrNonASCII(slice, @as(u32, @intCast(i)))) |j| {
b.generated_column += @as(i32, @intCast((@as(usize, j) - i) + 1));
i = j;
continue;
} else {
b.generated_column += @as(i32, @intCast(slice[i..].len)) + 1;
i = n;
break;
}
},
'\r', '\n', 0x2028, 0x2029 => {
// windows newline
if (c == '\r') {
const newline_check = b.last_generated_update + i + 1;
if (newline_check < output.len and output[newline_check] == '\n') {
continue;
}
}
// If we're about to move to the next line and the previous line didn't have
// any mappings, add a mapping at the start of the previous line.
if (needs_mapping) {
b.appendMappingWithoutRemapping(.{
.generated_line = b.prev_state.generated_line,
.generated_column = 0,
.source_index = b.prev_state.source_index,
.original_line = b.prev_state.original_line,
.original_column = b.prev_state.original_column,
});
}
b.prev_state.generated_line += 1;
b.prev_state.generated_column = 0;
b.generated_column = 0;
b.source_map.appendLineSeparator() catch unreachable;
// This new line doesn't have a mapping yet
b.line_starts_with_mapping = false;
needs_mapping = b.cover_lines_without_mappings and !b.line_starts_with_mapping and b.has_prev_state;
},
else => {
// Mozilla's "source-map" library counts columns using UTF-16 code units
b.generated_column += @as(i32, @intFromBool(c > 0xFFFF)) + 1;
},
}
}
b.last_generated_update = @as(u32, @truncate(output.len));
}
pub fn appendMapping(b: *ThisBuilder, current_state_: SourceMapState) void {
var current_state = current_state_;
// If the input file had a source map, map all the way back to the original
if (b.input_source_map) |input| {
if (input.find(current_state.original_line, current_state.original_column)) |mapping| {
current_state.source_index = mapping.sourceIndex();
current_state.original_line = mapping.originalLine();
current_state.original_column = mapping.originalColumn();
}
}
b.appendMappingWithoutRemapping(current_state);
}
pub fn appendMappingWithoutRemapping(b: *ThisBuilder, current_state: SourceMapState) void {
b.source_map.append(current_state, b.prev_state) catch unreachable;
b.prev_state = current_state;
b.has_prev_state = true;
}
pub fn addSourceMapping(b: *ThisBuilder, loc: Logger.Loc, output: []const u8) void {
if (
// don't insert mappings for same location twice
b.prev_loc.eql(loc) or
// exclude generated code from source
loc.start == Logger.Loc.Empty.start)
return;
b.prev_loc = loc;
const list = b.line_offset_tables;
// We have no sourcemappings.
// This happens for example when importing an asset which does not support sourcemaps
// like a png or a jpg
//
// import foo from "./foo.png";
//
if (list.len == 0) {
return;
}
const original_line = LineOffsetTable.findLine(b.line_offset_table_byte_offset_list, loc);
const line = list.get(@as(usize, @intCast(@max(original_line, 0))));
// Use the line to compute the column
var original_column = loc.start - @as(i32, @intCast(line.byte_offset_to_start_of_line));
if (line.columns_for_non_ascii.len > 0 and original_column >= @as(i32, @intCast(line.byte_offset_to_first_non_ascii))) {
original_column = line.columns_for_non_ascii.slice()[@as(u32, @intCast(original_column)) - line.byte_offset_to_first_non_ascii];
}
b.updateGeneratedLineAndColumn(output);
// If this line doesn't start with a mapping and we're about to add a mapping
// that's not at the start, insert a mapping first so the line starts with one.
if (b.cover_lines_without_mappings and !b.line_starts_with_mapping and b.generated_column > 0 and b.has_prev_state) {
b.appendMappingWithoutRemapping(.{
.generated_line = b.prev_state.generated_line,
.generated_column = 0,
.source_index = b.prev_state.source_index,
.original_line = b.prev_state.original_line,
.original_column = b.prev_state.original_column,
});
}
b.appendMapping(.{
.generated_line = b.prev_state.generated_line,
.generated_column = @max(b.generated_column, 0),
.source_index = b.prev_state.source_index,
.original_line = @max(original_line, 0),
.original_column = @max(original_column, 0),
});
// This line now has a mapping on it, so don't insert another one
b.line_starts_with_mapping = true;
}
};
}
pub const Builder = NewBuilder(VLQSourceMap);
};
/// https://sentry.engineering/blog/the-case-for-debug-ids
/// https://github.com/mitsuhiko/source-map-rfc/blob/proposals/debug-id/proposals/debug-id.md
/// https://github.com/source-map/source-map-rfc/pull/20
/// https://github.com/getsentry/rfcs/blob/main/text/0081-sourcemap-debugid.md#the-debugid-format
pub const DebugIDFormatter = struct {
id: u64 = 0,
pub fn format(self: DebugIDFormatter, comptime _: []const u8, _: std.fmt.FormatOptions, writer: anytype) !void {
// The RFC asks for a UUID, which is 128 bits (32 hex chars). Our hashes are only 64 bits.
// We fill the end of the id with "bun!bun!" hex encoded
var buf: [32]u8 = undefined;
const formatter = bun.fmt.hexIntUpper(self.id);
_ = std.fmt.bufPrint(&buf, "{}64756E2164756E21", .{formatter}) catch unreachable;
try writer.writeAll(&buf);
}
};
const assert = bun.assert;
pub const coverage = @import("./CodeCoverage.zig");
pub const VLQ = @import("./VLQ.zig");
pub const LineOffsetTable = @import("./LineOffsetTable.zig");
const decodeVLQAssumeValid = VLQ.decodeAssumeValid;
const decodeVLQ = VLQ.decode;