Segfault caused by macro oddities

[Validark]

Version

0.1.13

Platform

Linux 5be22774b6dc 5.19.0-76051900-generic #202207312230~1660780566~22.04~9d60db1 SMP PREEMPT_DYNAMIC Thu A x86_64 x86_64 x86_64 GNU/Linux

What steps will reproduce the bug?

This only happens on some runs, so one has to run bun dev and spam F5 to get the segfault.

bun create blank ./_new_test

src/index.js:

// import { graphql } from 'react-relay';

// graphql(['a', 'b']);
console.log("Hello via Bun!");

const a = { a: 1, b: 2, c: 3, d: 4, e: 5 }.b;
// console.log(a.b)

const date = new Date(1996, 8, 1, 0, 0, 0, 0).toUTCString();
const realDate = new Date(date).toISOString();

console.log(date)

console.log(typeof process.env.QUIET3, `"${process.env.QUIET3}"`);
console.log(typeof !process.env.QUIET3, !process.env.QUIET3);
console.log(typeof !!!!process.env.QUIET, !!!!process.env.QUIET);
console.log(typeof process.env.QUIET, `"${process.env.QUIET}"`);
console.log(typeof process.env.bagel, process.env.bagel);
console.log(typeof process.env.donut, process.env.donut);
console.log(typeof process.env.pie, process.env.pie);
console.log(typeof process.env.pie2, process.env.pie2);
console.log(typeof process.env.pie3, process.env.pie3);
console.log(typeof process.env.pie4, process.env.pie4);
// console.log(typeof process.env.pie5, process.env.pie5);
const k = 0.1.toString();
console.log(k)
const { bagel: bagelboi } = process.env;
const { env: { QUIET } } = process
console.log(QUIET)
const b = JSON.parse('{"a":1,"b":2,"c":3,"d":4}');
console.log(b.c);
process.env.pie5.b;

Make a bunfig.toml file:

# Set a default framework to use
# By default, bun will look for an npm package like `bun-framework-${framework}`, followed by `${framework}`

macros.react-relay.graphql = "bun-macro-relay"
macros.relay-runtime.graphql = "bun-macro-relay"

[define]
# Replace any usage of "process.env.bagel" with the string `lox`.
# The values are parsed as JSON, except single-quoted strings are supported and `'undefined'` becomes `undefined` in JS.
# This will probably change in a future release to be just regular TOML instead. It is a holdover from the CLI argument parsing.
"process.env.bagel" = "'lox'"
"process.env.donut" = "[1, 2]"
"process.env.pie" = "null"
"process.env.pie2" = 'noob'
"process.env.pie3" = '"noob"'
"process.env.pie4" = '`${noob}`'
"process.env.pie5" = '{"a":1,"b":2,"c":3}'

Now run:

FORCE_COLOR=1 QUIET= QUIET2= bun dev

Or (Linux x64):

FORCE_COLOR=1 QUIET= QUIET2= /build/bun/packages/debug-bun-linux-x64/bun-debug dev

After opening localhost:3000 and refreshing the page 4 to 10 times, we get a Segfault. I did not narrow the files down more because there are some other weird interactions going on.

When tsconfig.json is configured like so, we get another weird behavior:

{
	"compilerOptions": {
	  "lib": ["ESNext"],
	  "module": "esnext",
	  "target": "esnext",
	  "moduleResolution": "node",

	  // so that if your project isn't using TypeScript, it still has autocomplete
	  "allowJs": true,

	  // "bun-types" is the important part
	  "types": ["bun-types"]
	}
  }

The line process.env.pie5.b; is supposed to compile to ({ a: 1, b: 2, c: 3 }).b;, and correctly compiles the first time localhost:3000/ is opened. However, after refreshing the page 4 to 10 times it compiles to ({ "": 1, "": 2, string: 3 }).b;. (With slightly different environment variables I was about to get one of those keys to be object instead)

Unfortunately stack trace does not work on Linux so here's my handwritten trace for the Segfault:

main.zig
  60 |   cli.Cli.start(default_allocator, stdout, stderr, MainPanicHandler);

cli.zig
  76 |   Command.start(allocator, log) catch |err| {

cli.zig
 932 |   try DevCommand.exec(ctx);

dev_command.zig
   7 |   try Server.start(ctx.allocator, ctx.args, @TypeOf(ctx.debug), ctx.debug);

http.zig
4031 |   try server.run(ConnectionFeatures{.public_folder = .first,},);

http.zig
3609 |   server.handleConnection(&conn, comptime features);

http.zig
3829 |   req_ctx.handleRequest() catch |err| {

http.zig
3153 |   return ctx.handleGet();

http.zig
3147 |   try @call(.{ .modifier = .always_inline }, RequestContext.renderServeResult, .{ ctx, result });

http.zig
2473-4 |   if (!ctx.url.is_source_map)
                    ctx.bundler.buildWithResolveResult(

bundler.zig
890 |   .none, .esm => try bundler.printWithSourceMapMaybe(

bundler.zig
1141 |   .esm => try js_printer.printAst(

js_printer.zig, `stmt` is 
`
{
	loc: { start: -1 },
	data: {
		s_expr: {
			does_not_affect_tree_shaking: false,
			value: { loc: { start: -1 } }
		}
	}
}
`
5014 |   try printer.printStmt(stmt);

js_printer.zig
4031 |   p.printExpr(s.value, .lowest, ExprFlag.ExprResultIsUnused());

js_printer.zig
1631 |   p.printExpr(e.target, .postfix, target_flags);

js_printer.zig
2353 |   p.printExpr(e.right, right_level, flags);

js_printer.zig
1906 |   p.printFunc(e.func);

js_printer.zig
 933 |   p.printBlock(func.body.loc, func.body.stmts);

js_printer.zig
825 |   p.printBlockBody(stmts);

js_printer.zig
815 |   p.printStmt(stmt) catch unreachable;

js_printer.zig
4031 |   p.printExpr(s.value, .lowest, ExprFlag.ExprResultIsUnused());

js_printer.zig
1741 |   p.printExpr(e.target, .postfix, flags, );

js_printer.zig (property.key.data supposedly has a payload of `e_unary` according to debugger, but in the next layer it has an e_string whose `data` is `{ptr:0x00007fff00000484, len:5309989061088}`
1997 |   p.printProperty(property);

js_printer.zig
2580 |   key.resovleRopeIfNeeded(p.options.allocator);

js_printer.zig `ptr` is `"\xaa"` (i.e. null for debug mode) `this.data` is `{ptr:0x00007fff00000484, len:5309989061088}`
1680 |   @memcpy(ptr, this.data.ptr, this.data.len);

Here's the call stack from VSCode:

___lldb_unnamed_symbol4284 (@___lldb_unnamed_symbol4284:7)
src.js_ast.E.String.resovleRopeIfNeeded (/build/bun/src/js_ast.zig:1680)
src.js_printer.NewPrinter(false,src.js_printer.NewWriter(src.http.SocketPrinterInternal,src.http.SocketPrinterInternal.writeByte,src.http.SocketPrinterInternal.writeAll,src.http.SocketPrinterInternal.getLastByte,src.http.SocketPrinterInternal.getLastLastByte,src.http.SocketPrinterInternal.reserveNext,src.http.SocketPrinterInternal.advanceBy),src.linker.Linker,false,false,false,false,false).printProperty (/build/bun/src/js_printer.zig:2580)
src.js_printer.NewPrinter(false,src.js_printer.NewWriter(src.http.SocketPrinterInternal,src.http.SocketPrinterInternal.writeByte,src.http.SocketPrinterInternal.writeAll,src.http.SocketPrinterInternal.getLastByte,src.http.SocketPrinterInternal.getLastLastByte,src.http.SocketPrinterInternal.reserveNext,src.http.SocketPrinterInternal.advanceBy),src.linker.Linker,false,false,false,false,false).printExpr (/build/bun/src/js_printer.zig:1997)
src.js_printer.NewPrinter(false,src.js_printer.NewWriter(src.http.SocketPrinterInternal,src.http.SocketPrinterInternal.writeByte,src.http.SocketPrinterInternal.writeAll,src.http.SocketPrinterInternal.getLastByte,src.http.SocketPrinterInternal.getLastLastByte,src.http.SocketPrinterInternal.reserveNext,src.http.SocketPrinterInternal.advanceBy),src.linker.Linker,false,false,false,false,false).printExpr (/build/bun/src/js_printer.zig:1741)
src.js_printer.NewPrinter(false,src.js_printer.NewWriter(src.http.SocketPrinterInternal,src.http.SocketPrinterInternal.writeByte,src.http.SocketPrinterInternal.writeAll,src.http.SocketPrinterInternal.getLastByte,src.http.SocketPrinterInternal.getLastLastByte,src.http.SocketPrinterInternal.reserveNext,src.http.SocketPrinterInternal.advanceBy),src.linker.Linker,false,false,false,false,false).printStmt (/build/bun/src/js_printer.zig:4031)
src.js_printer.NewPrinter(false,src.js_printer.NewWriter(src.http.SocketPrinterInternal,src.http.SocketPrinterInternal.writeByte,src.http.SocketPrinterInternal.writeAll,src.http.SocketPrinterInternal.getLastByte,src.http.SocketPrinterInternal.getLastLastByte,src.http.SocketPrinterInternal.reserveNext,src.http.SocketPrinterInternal.advanceBy),src.linker.Linker,false,false,false,false,false).printBlockBody (/build/bun/src/js_printer.zig:815)
src.js_printer.NewPrinter(false,src.js_printer.NewWriter(src.http.SocketPrinterInternal,src.http.SocketPrinterInternal.writeByte,src.http.SocketPrinterInternal.writeAll,src.http.SocketPrinterInternal.getLastByte,src.http.SocketPrinterInternal.getLastLastByte,src.http.SocketPrinterInternal.reserveNext,src.http.SocketPrinterInternal.advanceBy),src.linker.Linker,false,false,false,false,false).printBlock (/build/bun/src/js_printer.zig:825)
src.js_printer.NewPrinter(false,src.js_printer.NewWriter(src.http.SocketPrinterInternal,src.http.SocketPrinterInternal.writeByte,src.http.SocketPrinterInternal.writeAll,src.http.SocketPrinterInternal.getLastByte,src.http.SocketPrinterInternal.getLastLastByte,src.http.SocketPrinterInternal.reserveNext,src.http.SocketPrinterInternal.advanceBy),src.linker.Linker,false,false,false,false,false).printFunc (/build/bun/src/js_printer.zig:933)
src.js_printer.NewPrinter(false,src.js_printer.NewWriter(src.http.SocketPrinterInternal,src.http.SocketPrinterInternal.writeByte,src.http.SocketPrinterInternal.writeAll,src.http.SocketPrinterInternal.getLastByte,src.http.SocketPrinterInternal.getLastLastByte,src.http.SocketPrinterInternal.reserveNext,src.http.SocketPrinterInternal.advanceBy),src.linker.Linker,false,false,false,false,false).printExpr (/build/bun/src/js_printer.zig:1906)
src.js_printer.NewPrinter(false,src.js_printer.NewWriter(src.http.SocketPrinterInternal,src.http.SocketPrinterInternal.writeByte,src.http.SocketPrinterInternal.writeAll,src.http.SocketPrinterInternal.getLastByte,src.http.SocketPrinterInternal.getLastLastByte,src.http.SocketPrinterInternal.reserveNext,src.http.SocketPrinterInternal.advanceBy),src.linker.Linker,false,false,false,false,false).printExpr (/build/bun/src/js_printer.zig:2353)
src.js_printer.NewPrinter(false,src.js_printer.NewWriter(src.http.SocketPrinterInternal,src.http.SocketPrinterInternal.writeByte,src.http.SocketPrinterInternal.writeAll,src.http.SocketPrinterInternal.getLastByte,src.http.SocketPrinterInternal.getLastLastByte,src.http.SocketPrinterInternal.reserveNext,src.http.SocketPrinterInternal.advanceBy),src.linker.Linker,false,false,false,false,false).printExpr (/build/bun/src/js_printer.zig:1631)
src.js_printer.NewPrinter(false,src.js_printer.NewWriter(src.http.SocketPrinterInternal,src.http.SocketPrinterInternal.writeByte,src.http.SocketPrinterInternal.writeAll,src.http.SocketPrinterInternal.getLastByte,src.http.SocketPrinterInternal.getLastLastByte,src.http.SocketPrinterInternal.reserveNext,src.http.SocketPrinterInternal.advanceBy),src.linker.Linker,false,false,false,false,false).printStmt (/build/bun/src/js_printer.zig:4031)
src.js_printer.printAst (/build/bun/src/js_printer.zig:5014)
src.bundler.Bundler.printWithSourceMapMaybe (/build/bun/src/bundler.zig:1141)
src.bundler.Bundler.buildWithResolveResult (/build/bun/src/bundler.zig:890)
src.http.RequestContext.renderServeResult (/build/bun/src/http.zig:2474)
src.http.RequestContext.handleGet (/build/bun/src/http.zig:3147)
src.http.RequestContext.handleRequest (/build/bun/src/http.zig:3153)
src.http.Server.handleConnection (/build/bun/src/http.zig:3829)
src.http.Server.run (/build/bun/src/http.zig:3609)
src.http.Server.start (/build/bun/src/http.zig:4031)
src.cli.dev_command.DevCommand.exec (/build/bun/src/cli/dev_command.zig:7)
src.cli.Command.start (/build/bun/src/cli.zig:932)
src.cli.Cli.start (/build/bun/src/cli.zig:76)
main (/build/bun/src/main.zig:60)
std.start.callMain (/build/zig/lib/std/start.zig:571)
std.start.initEventLoopAndCallMain (/build/zig/lib/std/start.zig:515)
std.start.callMainWithArgs (/build/zig/lib/std/start.zig:465)
std.start.main (/build/zig/lib/std/start.zig:480)
___lldb_unnamed_symbol3139 (@___lldb_unnamed_symbol3139:29)
__libc_start_main (@__libc_start_main:43)
_start (@_start:15)

Additional information

Perhaps there is some hashing issue going on?

[Electroid]

bun dev was changed in Bun v1.0, it will now run the "dev" script in your package.json. Because of that, this issue is no longer applicable.