Fix more jumpopts (in ternary op)

the code in expr_cond save nocode_wanted around some parts of expression evaluation, but at the wrong spots. If the evaluation of the condition itself (e.g. in the testcase the first whole ternary expression) resulted in CODE_OFF, then that was saved, and restored before return, even if in-between codegen would have CODE_ON'ed already. Thus the whole CODE_OFF state bled out to outside the expression evaluation and also disabled the whole if-block. Found by yarpgen v1 (seed 64).

Michael Matz committed 3 years ago

Commit 2cf3a6e1 parent ec818773 files · +18 −5Browse files

Unified · Split

3 files

tccgen.c +4 −5
tests/tests2/33_ternary_op.c +13 −0
tests/tests2/33_ternary_op.expect +1 −0

tccgen.c+4−5

     int tt, u, r1, r2, rc, t1, t2, islv, c, g;
     SValue sv;
     CType type;
-    int ncw_prev;
     expr_lor();
     if (tok == '?') {
             tt = gvtst(0, 0);
         }
-        ncw_prev = nocode_wanted;
         if (c == 0)
           nocode_wanted++;
         if (!g)
         } else
           u = 0;
-        nocode_wanted = ncw_prev;
+        if (c == 0)
+          nocode_wanted--;
         if (c == 1)
           nocode_wanted++;
         skip(':');
             /* combine jump targets of 2nd op with VT_CMP of 1st op */
             gvtst_set(0, t1);
             gvtst_set(1, t2);
-            nocode_wanted = ncw_prev;
             //  tcc_warning("two conditions expr_cond");
             return;
         }
             tt = gjmp(0);
         }
         gsym(u);
-        nocode_wanted = ncw_prev;
+        if (c == 1)
+          nocode_wanted--;
         /* this is horrible, but we must also convert first
            operand */

tests/tests2/33_ternary_op.c+13−0

@@ -39,6 +39,17 @@ static int getme(struct condstruct* s, int i) · 38 unmodified lines
39	return i1 + i2 + i3 + i4;	39	return i1 + i2 + i3 + i4;
40	}	40	}
41		41
		42	int someglobal;
		43
		44	void constantcond(void)
		45	{
		46	/* This was broken by 8227db3a2, it saved/restored the CODE_OFF state
		47	during the expression and that bled out to the outer one disabling
		48	codegen for if-body. */
		49	if (( (someglobal ? 0 : 0) ? 8 : 9))
		50	printf("okay\n");
		51	}
		52
42	int main()	53	int main()
43	{	54	{
44	int Count;	55	int Count;
@@ -73,6 +84,8 @@ int main() · 28 unmodified lines
73	//0 ? a : 0.0;	84	//0 ? a : 0.0;
74	}	85	}
75		86
		87	constantcond();
		88
76		89
77	return 0;	90	return 0;
78	}	91	}

tests/tests2/33_ternary_op.expect+1−0

@@ -10,3 +10,4 @@ · 9 unmodified lines
10	24	10	24
11	27	11	27
12	152	12	152
		13	okay

Fix more jumpopts (in ternary op)

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