?: operator broken for vector condition

[divVerent]

Code:

void print(string s) = #1;

void bar(vector v) {
        print(v ? "t\n" : "f\n");
};
void barf(vector v) {
        if (v)
                print("t\n");
        else
                print("f\n");
};
void blarf(vector v) {
        if (!v)
                print("f\n");
        else
                print("t\n");
};

Command:

./gmqcc -std=gmqcc -Wdebug foo.qc && ./qcvm -disasm progs.dat

Output:

FUNCTION "print" = builtin #1
FUNCTION "bar"
 <> IFNOT       [@53] 0,                    5
 <> STORE_S     [@38] IMMEDIATE "t\n",      [@56] (null),               (none)
 <> STORE_S     [@56] (null),               [@4] (null),                (none)
 <> CALL1       [@28] print (1),            
 <> RETURN      <null>,                     <null>,                     <null>,                     
 <> STORE_S     [@39] IMMEDIATE "f\n",      [@56] (null),               (none)
 <> GOTO        -4
FUNCTION "barf"
 <> NOT_V       [@57] 0,                    <null>,                     [@60] 0,                    
 <> IFNOT       [@60] 0,                    4
 <> STORE_S     [@39] IMMEDIATE "f\n",      [@4] (null),                (none)
 <> CALL1       [@28] print (1),            
 <> RETURN      <null>,                     <null>,                     <null>,                     
 <> STORE_S     [@38] IMMEDIATE "t\n",      [@4] (null),                (none)
 <> CALL1       [@28] print (1),            
 <> GOTO        -3
FUNCTION "blarf"
 <> NOT_V       [@61] 0,                    <null>,                     [@64] 0,                    
 <> IFNOT       [@64] 0,                    4
 <> STORE_S     [@39] IMMEDIATE "f\n",      [@4] (null),                (none)
 <> CALL1       [@28] print (1),            
 <> RETURN      <null>,                     <null>,                     <null>,                     
 <> STORE_S     [@38] IMMEDIATE "t\n",      [@4] (null),                (none)
 <> CALL1       [@28] print (1),            
 <> GOTO        -3

Note how bar doesn't use NOT_V but calls IFNOT on the vector directly. This just looks at its x component.

I suspect the bug is that exprs[0] in parser.cpp's call to new ast_ternary has not been fed through process_condition first, which is what normally takes care of inserting NOT_V for vector conditions. Probably a simple fix.

[divVerent]

Affected Xonotic code:

https://gitlab.com/xonotic/xonotic-data.pk3dir/-/blob/master/qcsrc/common/monsters/sv_monsters.qc?ref_type=heads#L864

	this.steerto = steerlib_attract2(this, ((this.monster_face) ? this.monster_face : this.moveto), 0.5, 500, 0.95);

[divVerent]

Confirmed that entire process_condition logic is missing, by changing the type to string and running the compiler with -ffalse-empty-strings -fno-true-empty-strings:

FUNCTION "print" = builtin #1
FUNCTION "bar"
 <> IFNOT       [@51] 0,                    5
 <> STORE_S     [@38] IMMEDIATE "t\n",      [@52] (null),               (none)
 <> STORE_S     [@52] (null),               [@4] (null),                (none)
 <> CALL1       [@28] print (1),            
 <> RETURN      <null>,                     <null>,                     <null>,                     
 <> STORE_S     [@39] IMMEDIATE "f\n",      [@52] (null),               (none)
 <> GOTO        -4
FUNCTION "barf"
 <> NOT_S       [@53] 0,                    <null>,                     [@54] 0,                    
 <> IFNOT       [@54] 0,                    4
 <> STORE_S     [@39] IMMEDIATE "f\n",      [@4] (null),                (none)
 <> CALL1       [@28] print (1),            
 <> RETURN      <null>,                     <null>,                     <null>,                     
 <> STORE_S     [@38] IMMEDIATE "t\n",      [@4] (null),                (none)
 <> CALL1       [@28] print (1),            
 <> GOTO        -3
FUNCTION "blarf"
 <> NOT_S       [@55] 0,                    <null>,                     [@56] 0,                    
 <> IFNOT       [@56] 0,                    4
 <> STORE_S     [@39] IMMEDIATE "f\n",      [@4] (null),                (none)
 <> CALL1       [@28] print (1),            
 <> RETURN      <null>,                     <null>,                     <null>,                     
 <> STORE_S     [@38] IMMEDIATE "t\n",      [@4] (null),                (none)
 <> CALL1       [@28] print (1),            
 <> GOTO        -3

bar ignores those options too, whereas the others then use NOT_S.