#3107 --debug switch generate duplicate labels for the lines of code that contain equal text

[Tony Pavlov]

I have a code of main(), that is placed in ISO.c file. lines 164-173 contain this code:

    player.scene_item->x = to_x(player.x, player.y, player.z), 
    player.scene_item->y = to_y(player.x, player.y, player.z), 
    player.scene_item->coords = to_coords(player.x, player.y, player.z);

    // copy scene to RAM
    scene_count = copy_scene(position->room_bank, position->room, scene_items);

    // if scene not empty
    if (scene_count) {

and far below in the same main() function on lines 314-317 i have that code:

            clear_shadow_buffer();
            // decompress scene to 3D map
            scene_count = copy_scene(position->room_bank, position->room, scene_items);
            if (scene_count) scene_to_map(scene_items, &collision_buf); else clear_map(&collision_buf);                

when i compile that code with --debug switch, i get that ASM code for the first case:

    call    _clear_shadow_buffer
    C$ISO.c$316$3_0$153 = .
    .globl  C$ISO.c$316$3_0$153
;src\ISO.c:316: scene_count = copy_scene(position->room_bank, position->room, scene_items);
    C$ISO.c$170$1_0$123 = .
    .globl  C$ISO.c$170$1_0$123
;src\ISO.c:170: scene_count = copy_scene(position->room_bank, position->room, scene_items);
;   genAssign
;fetchPairLong
;fetchLitPair
    ld  hl, #_position + 1

and this ASM code for the second:

;src\ISO.c:314: clear_shadow_buffer();
;   genCall
    call    _clear_shadow_buffer
    C$ISO.c$316$3_0$153 = .
    .globl  C$ISO.c$316$3_0$153
;src\ISO.c:316: scene_count = copy_scene(position->room_bank, position->room, scene_items);
    C$ISO.c$170$1_0$123 = .
    .globl  C$ISO.c$170$1_0$123
;src\ISO.c:170: scene_count = copy_scene(position->room_bank, position->room, scene_items);
;   genAssign
;fetchPairLong

at the end, in the map file we have:

     00001B53  C$ISO.c$314$3_0$153                ISO
[cut]
     00001B56  C$ISO.c$170$1_0$123                ISO
[cut]
     00001B5D  C$ISO.c$316$3_0$153                ISO

so:
1. the label for line 170 is set to some correct address near the beginning, and then gets overwritten with the incorrect address 00001B56 later.
2. label for line 316 is set to some incorrect address near the beginning, and then get overwritten by a correct address.

those labels are required for debug adapter for vs.code, that is almost working, but fails to break on some lines due to this problem.

[Tony Pavlov]

some kind of reverse resolving of a label by the source line content?

[Philipp Klaus Krause]

Hmm, at first this looks like some redundancy elimination might move around code common to both lines, so in the end we don't really know which asm lines came from which C lines?

Do you see the same problem when compiling with some optimizations disabled, e.g. by using --nolospre or --nogcse?

[Tony Pavlov]

--nolospre fixes the issue. isn't it possible to resolve that somehow? at least maybe total absence of those labels will be less confusing than duplicates?

[Tony Pavlov]

S:Lrythm.main$__3276800010$5_0$128({2}SI:U),R,0,0,[c,b]
S:Lrythm.main$__3276800011$5_0$145({2}SI:U),R,0,0,[]
S:Lrythm.main$__3276800012$5_0$145({2}SI:U),R,0,0,[l,h]

hm... __3276800011 is a local register-allocated variable that is bind to no registers? names are ok, they are static.