translate-c panic on ffmpeg headers

[jedisct1]

translate-c panics in a funny way on FFmpeg headers:

zig translate-c -I/usr/local/opt/ffmpeg/include /usr/local/opt/ffmpeg/include/libavformat/avformat.h

thread 4621208 panic: reached unreachable code
/Users/j/src/zig/lib/std/builtin.zig:688:54: 0x10ad0ff88 in std.builtin.default_panic (zig1)
            std.debug.panicExtra(error_return_trace, first_trace_addr, "{s}", .{msg});
                                                     ^
/Users/j/src/zig/lib/std/mem/Allocator.zig:290:40: 0x10ae9551d in std.mem.Allocator.allocAdvancedWithRetAddr (zig1)
    const byte_slice = try self.allocFn(self, byte_count, a, len_align, return_address);
                                       ^
/Users/j/src/zig/lib/std/fmt.zig:88:9: 0x10b29a386 in std.fmt.format (zig1)
) !void {
        ^
/Users/j/src/zig/src/translate_c.zig:2510:32: 0x10b1a716c in translate_c.transCharLiteral (zig1)
            // @as(T, x)
                               ^
/Users/j/src/zig/lib/std/fmt.zig:248:20: 0x10b2a0495 in std.fmt.format (zig1)
        options = .{};
                   ^
/Users/j/src/zig/lib/std/zig/fmt.zig:48:17: 0x10b2a1481 in std.zig.fmt.formatEscapes (zig1)
        '\\' => try writer.writeAll("\\\\"),
                ^
/Users/j/src/zig/lib/std/fmt.zig:248:20: 0x10b4458b1 in std.fmt.format (zig1)
        options = .{};
                   ^
/Users/j/src/zig/lib/std/fmt.zig:219:32: 0x10b29cec7 in std.fmt.format (zig1)
            try writer.writeAll(fmt[start_index..end_index]);
                               ^
/Users/j/src/zig/lib/std/zig/render.zig:245:17: 0x10b2a3f07 in std.zig.render.renderExpression (zig1)
                try renderToken(ais, tree, payload_token - 1, .none); // |
                ^
/Users/j/src/zig/lib/std/fmt.zig:719:9: 0x10b1a8332 in std.fmt.formatText (zig1)
            options: std.fmt.FormatOptions,
        ^
/Users/j/src/zig/lib/std/fmt.zig:1474:46: 0x10b07a2dd in std.fmt.allocPrint (zig1)
    std.testing.expect((try parseUnsigned(u32, "DeadBeef", 16)) == 0xDEADBEEF);
                                             ^
/Users/j/src/zig/src/translate_c/ast.zig:2517:25: 0x10af50e00 in translate_c.ast.renderParams (zig1)

                        ^
/Users/j/src/zig/lib/std/mem/Allocator.zig:439:25: 0x10adee693 in std.mem.Allocator.alignedShrinkWithRetAddr (zig1)
    _ = self.shrinkBytes(old_byte_slice, Slice.alignment, byte_count, 0, return_address);
                        ^
/Users/j/src/zig/src/Cache.zig:539:0: 0x10ad9d903 in Cache.Manifest.final (zig1)
                    std.log.err("failed parsing {s}: {s}", .{ dep_file_basename, error_buf.items });

/Users/j/src/zig/src/main.zig:2187:35: 0x10ae0c9b0 in main.cmdTranslateC (zig1)
            try man.addDepFilePost(zig_cache_tmp_dir, dep_basename);
                                  ^
/Users/j/src/zig/src/main.zig:1725:11: 0x10ad3e22b in main.buildOutputType (zig1)
    defer if (root_pkg) |p| p.destroy(gpa);
          ^
/Users/j/src/zig/src/main.zig:178:37: 0x10ad14ada in main.mainArgs (zig1)
        return buildOutputType(gpa, arena, args, .run);
                                    ^
/Users/j/src/zig/lib/std/debug.zig:287:58: 0x10ad13f1f in std.debug.panicExtra (zig1)
                    stderr.print("thread {d} panic: ", .{current_thread_id}) catch os.abort();
                                                         ^
???:?:?: 0x7fff20406f3c in ??? (???)
???:?:?: 0x3 in ??? (???)

This is with FFmpeg 4.3.2, standard install on macOS with Homebrew.

[andrewrk]

I have no doubt that you found a bug, but could you double check that you have rebuilt zig after pulling the latest standard library changes? This stack trace looks like what happens when the source and binary mismatch. I think if you rebuild and re-run the test case, it will produce a more helpful stack trace.

[jedisct1]

New stack trace, Zig just recompiled from 3ad9cb8

thread 4841080 panic: reached unreachable code
/Users/j/src/zig/lib/std/builtin.zig:688:54: 0x10e13f808 in std.builtin.default_panic (zig1)
            std.debug.panicExtra(error_return_trace, first_trace_addr, "{s}", .{msg});
                                                     ^
/Users/j/src/zig/lib/std/mem/Allocator.zig:290:40: 0x10e2c4e1d in std.mem.Allocator.allocAdvancedWithRetAddr (zig1)
    const byte_slice = try self.allocFn(self, byte_count, a, len_align, return_address);
                                       ^
/Users/j/src/zig/lib/std/fmt.zig:0:13: 0x10e6ca736 in std.fmt.format (zig1)
/Users/j/src/zig/src/translate_c.zig:1918:39: 0x10e5d6eec in translate_c.literalFitsInType (zig1)
    const is_signed = cIsSignedInteger(qt);
                                      ^
/Users/j/src/zig/lib/std/fmt.zig:358:9: 0x10e6d0845 in std.fmt.format (zig1)
        try formatType(
        ^
/Users/j/src/zig/lib/std/zig/fmt.zig:45:17: 0x10e6d1831 in std.zig.fmt.formatEscapes (zig1)
        '\n' => try writer.writeAll("\\n"),
                ^
/Users/j/src/zig/lib/std/fmt.zig:219:13: 0x10e878801 in std.fmt.format (zig1)
            try writer.writeAll(fmt[start_index..end_index]);
            ^
/Users/j/src/zig/src/translate_c.zig:3505:44: 0x10e6cd277 in translate_c.cIsSignedInteger (zig1)
    if (c_type.getTypeClass() != .Builtin) return false;
                                           ^
/Users/j/src/zig/lib/std/zig/render.zig:245:17: 0x10e6d42b7 in std.zig.render.renderExpression (zig1)
                try renderToken(ais, tree, payload_token - 1, .none); // |
                ^
/Users/j/src/zig/lib/std/mem/Allocator.zig:296:23: 0x10e5d80b2 in std.mem.Allocator.allocAdvancedWithRetAddr (zig1)
    @memset(byte_slice.ptr, undefined, byte_slice.len);
                      ^
/Users/j/src/zig/lib/std/fmt.zig:0:17: 0x10e4a943d in std.fmt.allocPrint (zig1)
/Users/j/src/zig/src/translate_c/ast.zig:2525:25: 0x10e380640 in translate_c.ast.renderParams (zig1)
        if (i != 0) _ = try c.addToken(.comma, ",");
                        ^
/Users/j/src/zig/lib/std/mem/Allocator.zig:439:25: 0x10e21e3c3 in std.mem.Allocator.alignedShrinkWithRetAddr (zig1)
    _ = self.shrinkBytes(old_byte_slice, Slice.alignment, byte_count, 0, return_address);
                        ^
/Users/j/src/zig/src/Cache.zig:547:0: 0x10e1cd1f3 in Cache.Manifest.final (zig1)
    pub fn final(self: *Manifest) [hex_digest_len]u8 {

/Users/j/src/zig/src/main.zig:2187:35: 0x10e23c6e0 in main.cmdTranslateC (zig1)
            try man.addDepFilePost(zig_cache_tmp_dir, dep_basename);
                                  ^
/Users/j/src/zig/src/main.zig:1725:11: 0x10e16daab in main.buildOutputType (zig1)
    defer if (root_pkg) |p| p.destroy(gpa);
          ^
/Users/j/src/zig/src/main.zig:178:37: 0x10e14435a in main.mainArgs (zig1)
        return buildOutputType(gpa, arena, args, .run);
                                    ^
/Users/j/src/zig/lib/std/debug.zig:287:58: 0x10e14379f in std.debug.panicExtra (zig1)
                    stderr.print("thread {d} panic: ", .{current_thread_id}) catch os.abort();
                                                         ^
???:?:?: 0x7fff20406f3c in ??? (???)
???:?:?: 0x4 in ??? (???)

[andrewrk]

Not sure what's going on with your zig installation - when I run it I get a stack trace that points to unreachable, as expected:

[nix-shell:~/Downloads/zig/build]$ ./zig translate-c ~/local/ffmpeg/include/libavformat/avformat.h -I ~/local/ffmpeg/include/ -lc
thread 19650 panic: reached unreachable code
/home/andy/Downloads/zig/lib/std/debug.zig:223:14: 0xad3fa8 in std.debug.assert (zig1)
    if (!ok) unreachable; // assertion failure
             ^
/home/andy/Downloads/zig/lib/std/zig/ast.zig:114:15: 0xc52a8b in std.zig.ast.Tree.tokenSlice (zig1)
        assert(token.tag == token_tag);
              ^
/home/andy/Downloads/zig/lib/std/zig/render.zig:2449:30: 0x10445c5 in std.zig.render.tokenSliceForRender (zig1)
    var ret = tree.tokenSlice(token_index);
                             ^
/home/andy/Downloads/zig/lib/std/zig/render.zig:2273:39: 0xf51dae in std.zig.render.renderToken (zig1)
    const lexeme = tokenSliceForRender(tree, token_index);
                                      ^
/home/andy/Downloads/zig/lib/std/zig/render.zig:192:30: 0x104a62e in std.zig.render.renderExpression (zig1)
        => return renderToken(ais, tree, main_tokens[node], space),
                             ^
/home/andy/Downloads/zig/lib/std/zig/render.zig:378:33: 0x104b61a in std.zig.render.renderExpression (zig1)
            try renderExpression(gpa, ais, tree, infix.lhs, .space);
                                ^
/home/andy/Downloads/zig/lib/std/zig/render.zig:2152:29: 0x1214355 in std.zig.render.renderCall (zig1)
        try renderExpression(gpa, ais, tree, param_node, .none);
                            ^
/home/andy/Downloads/zig/lib/std/zig/render.zig:457:29: 0x10470b7 in std.zig.render.renderExpression (zig1)
        => return renderCall(gpa, ais, tree, tree.callFull(node), space),
                            ^
/home/andy/Downloads/zig/lib/std/zig/render.zig:985:25: 0x104db47 in std.zig.render.renderVarDecl (zig1)
    try renderExpression(gpa, ais, tree, var_decl.ast.init_node, .semicolon);
                        ^
/home/andy/Downloads/zig/lib/std/zig/render.zig:143:49: 0xf52f24 in std.zig.render.renderMember (zig1)
        .simple_var_decl => return renderVarDecl(gpa, ais, tree, tree.simpleVarDecl(decl)),
                                                ^
/home/andy/Downloads/zig/lib/std/zig/render.zig:50:25: 0xe272cd in std.zig.render.renderMembers (zig1)
        try renderMember(gpa, ais, tree, member, .newline);
                        ^
/home/andy/Downloads/zig/lib/std/zig/render.zig:37:22: 0xd0e70d in std.zig.render.renderTree (zig1)
    try renderMembers(buffer.allocator, ais, tree, tree.rootDecls());
                     ^
/home/andy/Downloads/zig/lib/std/zig/ast.zig:67:50: 0xbaccb3 in std.zig.ast.Tree.renderToArrayList (zig1)
        return @import("./render.zig").renderTree(buffer, tree);
                                                 ^
/home/andy/Downloads/zig/lib/std/zig/ast.zig:62:35: 0xb5e502 in std.zig.ast.Tree.render (zig1)
        try tree.renderToArrayList(&buffer);
                                  ^
/home/andy/Downloads/zig/src/main.zig:2203:42: 0xbca64f in main.cmdTranslateC (zig1)
        const formatted = try tree.render(comp.gpa);
                                         ^
/home/andy/Downloads/zig/src/main.zig:1906:29: 0xb01d49 in main.buildOutputType (zig1)
        return cmdTranslateC(comp, arena, have_enable_cache);
                            ^
/home/andy/Downloads/zig/src/main.zig:184:31: 0xad8fef in main.mainArgs (zig1)
        return buildOutputType(gpa, arena, args, .translate_c);
                              ^
/home/andy/Downloads/zig/src/stage1.zig:45:24: 0xad843e in main (zig1)
        stage2.mainArgs(gpa, arena, args) catch unreachable;
                       ^
Aborted (core dumped)

This appears to be a recent regression caused by #7920.

[LemonBoy]

Reduced:

#define BAR FOO(0BGR, Q)

[Vexu]

Can't reproduce with zig translate-c /usr/include/libavformat/avformat.h -lc -lavcodec on version 0.8.0-dev.1396+5bd9a6451. nvm zig was built with RelWithDebInfo.