Compile error on empty string debug warn argument

[tiehuis]

pub fn main() -> %void {
    @import("std").debug.warn("{}", "");
}

Results in the following error:

$ zig build-exe test.zig
zig: /home/me/src/zig/src/ir.cpp:9708: VariableTableEntry* get_fn_var_by_index(FnTableEntry*, size_t): Assertion `gen_param_info != nullptr' failed.

Backtrace

#4  0x0000555555dbc3af in get_fn_var_by_index (fn_entry=0x5555596689a0, index=0) at /home/me/src/zig/src/ir.cpp:9708
#5  0x0000555555dbd560 in ir_analyze_fn_call (ira=0x5555596747a0, call_instruction=0x5555596737a0, fn_entry=0x555557a967f0, fn_type=0x555557a97b50, fn_ref=0x0, first_arg_ptr=0x555559675940, comptime_fn_call=false, fn_inline=FnInlineAuto) at /home/me/src/zig/src/ir.cpp:9986
#6  0x0000555555dbe3b5 in ir_analyze_instruction_call (ira=0x5555596747a0, call_instruction=0x5555596737a0) at /home/me/src/zig/src/ir.cpp:10189
#7  0x0000555555dd0206 in ir_analyze_instruction_nocast (ira=0x5555596747a0, instruction=0x5555596737a0) at /home/me/src/zig/src/ir.cpp:15200
#8  0x0000555555dd09a3 in ir_analyze_instruction (ira=0x5555596747a0, instruction=0x5555596737a0) at /home/me/src/zig/src/ir.cpp:15366
#9  0x0000555555dd0c46 in ir_analyze (codegen=0x5555576d6dc0, old_exec=0x555559668a10, new_exec=0x555559668aa8, expected_type=0x5555576e4b90, expected_type_source_node=0x5555577846d0) at /home/me/src/zig/src/ir.cpp:15417
#10 0x0000555555d6a078 in analyze_fn_ir (g=0x5555576d6dc0, fn_table_entry=0x5555596689a0, return_type_node=0x5555577846d0) at /home/me/src/zig/src/analyze.cpp:3641
#11 0x0000555555d6a367 in analyze_fn_body (g=0x5555576d6dc0, fn_table_entry=0x5555596689a0) at /home/me/src/zig/src/analyze.cpp:3693
#12 0x0000555555d6af7c in semantic_analyze (g=0x5555576d6dc0) at /home/me/src/zig/src/analyze.cpp:3897
#13 0x0000555555d9720b in gen_root_source (g=0x5555576d6dc0) at /home/me/src/zig/src/codegen.cpp:5744
#14 0x0000555555d9843a in codegen_build (g=0x5555576d6dc0) at /home/me/src/zig/src/codegen.cpp:6064
#15 0x0000555555de65c7 in main (argc=3, argv=0x7fffffffdd28) at /home/me/src/zig/src/main.cpp:852

[andrewrk]

I believe this is #557. I made it so the above code now does this:

/home/andy/dev/zig/build/lib/zig/std/debug/index.zig:30:23: error: compiler bug: var args can't handle void. https://github.com/zig-lang/zig/issues/557
    stderr.print(fmt, args) catch return;
                      ^
/home/andy/dev/zig/build/test.zig:11:30: note: called from here
    @import("std").debug.warn("{}", "");
                             ^

we'll probably leave #557 broken and only fix it in the self hosted compiler.