Compiler segfault for unqualified enum value in some contexts.

[MortimerSnerd]

Using commit abe7305, saw it also on commit from mid Feb.

Happens compiling the following code with zig build-exe:

const std = @import("std");

pub const FrameResponse = enum {
    Running,
    Finished,
    CreateCancelled,
};

const Something = enum {
    AA,
    BB,
};

pub fn handleFrame(dT: f32, st: Something) !FrameResponse {
    if (dT == 0) return error.BadTime;
    const rv = switch (st) {
        .AA => FrameResponse.Running,
        .BB => blk: {
            if (true) break :blk .Running;  // NOTE: Qualifying the enum here makes the compile succeed.
            break :blk .Finished;
        },
    };

    return rv;
}

pub fn main() !void {
    _ = try handleFrame(1, .AA);
}

Qualifying line .Running on line #19 makes the compile succeed. Small changes like removing the error union from the handleFrame function, or removing the enum type qualification from line #17 makes the compile not crash, giving a compile error instead: error: cannot store runtime value in type '(enum literal)'

The stack from the compile:

Segmentation fault at address 0x8
/home/pkelley/src/zig/src/buffer.cpp:68:5: 0x857300 in buf_hash (/home/pkelley/src/zig/src/buffer.cpp)
    assert(buf->list.length);
    ^
/home/pkelley/src/zig/src/hash_map.hpp:238:22: 0x8470e3 in key_to_index (/home/pkelley/src/zig/src/analyze.cpp)
        return (int)(HashFunction(key) % ((uint32_t)_capacity));
                     ^
/home/pkelley/src/zig/src/hash_map.hpp:223:27: 0x846f13 in internal_get (/home/pkelley/src/zig/src/analyze.cpp)
        int start_index = key_to_index(key);
                          ^
/home/pkelley/src/zig/src/hash_map.hpp:81:16: 0x84510c in maybe_get (/home/pkelley/src/zig/src/analyze.cpp)
        return internal_get(key);
               ^
/home/pkelley/src/zig/src/analyze.cpp:4299:61: 0x82b520 in find_enum_type_field (/home/pkelley/src/zig/src/analyze.cpp)
    auto entry = enum_type->data.enumeration.fields_by_name.maybe_get(name);
                                                            ^
/home/pkelley/src/zig/src/ir.cpp:12076:36: 0x899786 in ir_resolve_peer_types (/home/pkelley/src/zig/src/ir.cpp)
            TypeEnumField *field = find_enum_type_field(prev_type, cur_inst->value->data.x_enum_literal);
                                   ^
/home/pkelley/src/zig/src/ir.cpp:20218:42: 0x8c7bd0 in ir_analyze_instruction_phi (/home/pkelley/src/zig/src/ir.cpp)
            peer_parent->resolved_type = ir_resolve_peer_types(ira,
                                         ^
/home/pkelley/src/zig/src/ir.cpp:29270:20: 0x89753d in ir_analyze_instruction_base (/home/pkelley/src/zig/src/ir.cpp)
            return ir_analyze_instruction_phi(ira, (IrInstSrcPhi *)instruction);
                   ^
/home/pkelley/src/zig/src/ir.cpp:29572:38: 0x896846 in ir_analyze (/home/pkelley/src/zig/src/ir.cpp)
        IrInstGen *new_instruction = ir_analyze_instruction_base(ira, old_instruction);
                                     ^
/home/pkelley/src/zig/src/analyze.cpp:4810:34: 0x83ca9a in analyze_fn_ir (/home/pkelley/src/zig/src/analyze.cpp)
    ZigType *block_return_type = ir_analyze(g, fn->ir_executable,
                                 ^
/home/pkelley/src/zig/src/analyze.cpp:4926:5: 0x82c5eb in analyze_fn_body (/home/pkelley/src/zig/src/analyze.cpp)
    analyze_fn_ir(g, fn_table_entry, return_type_node);
    ^
/home/pkelley/src/zig/src/analyze.cpp:4578:13: 0x82c2a9 in resolve_inferred_error_set (/home/pkelley/src/zig/src/analyze.cpp)
            analyze_fn_body(g, infer_fn);
            ^
/home/pkelley/src/zig/src/ir.cpp:26740:18: 0x8d3e67 in ir_analyze_instruction_test_err (/home/pkelley/src/zig/src/ir.cpp)
            if (!resolve_inferred_error_set(ira->codegen, err_set_type, instruction->base.base.source_node)) {
                 ^
/home/pkelley/src/zig/src/ir.cpp:29386:20: 0x897ae7 in ir_analyze_instruction_base (/home/pkelley/src/zig/src/ir.cpp)
            return ir_analyze_instruction_test_err(ira, (IrInstSrcTestErr *)instruction);
                   ^
/home/pkelley/src/zig/src/ir.cpp:29572:38: 0x896846 in ir_analyze (/home/pkelley/src/zig/src/ir.cpp)
        IrInstGen *new_instruction = ir_analyze_instruction_base(ira, old_instruction);
                                     ^
/home/pkelley/src/zig/src/analyze.cpp:4810:34: 0x83ca9a in analyze_fn_ir (/home/pkelley/src/zig/src/analyze.cpp)
    ZigType *block_return_type = ir_analyze(g, fn->ir_executable,
                                 ^
/home/pkelley/src/zig/src/analyze.cpp:4926:5: 0x82c5eb in analyze_fn_body (/home/pkelley/src/zig/src/analyze.cpp)
    analyze_fn_ir(g, fn_table_entry, return_type_node);
    ^
/home/pkelley/src/zig/src/analyze.cpp:4578:13: 0x82c2a9 in resolve_inferred_error_set (/home/pkelley/src/zig/src/analyze.cpp)
            analyze_fn_body(g, infer_fn);
            ^
/home/pkelley/src/zig/src/ir.cpp:26740:18: 0x8d3e67 in ir_analyze_instruction_test_err (/home/pkelley/src/zig/src/ir.cpp)
            if (!resolve_inferred_error_set(ira->codegen, err_set_type, instruction->base.base.source_node)) {
                 ^
/home/pkelley/src/zig/src/ir.cpp:29386:20: 0x897ae7 in ir_analyze_instruction_base (/home/pkelley/src/zig/src/ir.cpp)
            return ir_analyze_instruction_test_err(ira, (IrInstSrcTestErr *)instruction);
                   ^
/home/pkelley/src/zig/src/ir.cpp:29572:38: 0x896846 in ir_analyze (/home/pkelley/src/zig/src/ir.cpp)
        IrInstGen *new_instruction = ir_analyze_instruction_base(ira, old_instruction);
                                     ^
/home/pkelley/src/zig/src/analyze.cpp:4810:34: 0x83ca9a in analyze_fn_ir (/home/pkelley/src/zig/src/analyze.cpp)
    ZigType *block_return_type = ir_analyze(g, fn->ir_executable,
                                 ^
/home/pkelley/src/zig/src/analyze.cpp:4926:5: 0x82c5eb in analyze_fn_body (/home/pkelley/src/zig/src/analyze.cpp)
    analyze_fn_ir(g, fn_table_entry, return_type_node);
    ^
/home/pkelley/src/zig/src/analyze.cpp:5038:13: 0x82d590 in semantic_analyze (/home/pkelley/src/zig/src/analyze.cpp)
            analyze_fn_body(g, fn_entry);
            ^
/home/pkelley/src/zig/src/codegen.cpp:9441:9: 0x861b73 in gen_root_source (/home/pkelley/src/zig/src/codegen.cpp)
        semantic_analyze(g);
        ^
/home/pkelley/src/zig/src/codegen.cpp:10504:13: 0x860473 in codegen_build_and_link (/home/pkelley/src/zig/src/codegen.cpp)
            gen_root_source(g);
            ^
/home/pkelley/src/zig/src/main.cpp:1256:17: 0x81e32b in main0 (/home/pkelley/src/zig/src/main.cpp)
                codegen_build_and_link(g);
                ^
/home/pkelley/src/zig/src/main.cpp:1406:19: 0x8193c3 in main (/home/pkelley/src/zig/src/main.cpp)
    auto result = main0(argc, argv);
                  ^

[nektro]

and changing the switch to this trips an ICE

    return switch (st) {
        .AA => .Running,
        .BB => blk: {
            if (true) break :blk .Running;
            break :blk .Finished;
        },
    };

[Vexu]

Works in self-hosted, similar enough tests exits in test/behavior/eval.zig.