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).
Unified · Split
| @@ -6297,7 +6297,6 @@ static void expr_cond(void) · 6296 unmodified lines | ||
| 6297 | 6297 | int tt, u, r1, r2, rc, t1, t2, islv, c, g; |
| 6298 | 6298 | SValue sv; |
| 6299 | 6299 | CType type; |
| 6300 | − int ncw_prev; | |
| 6301 | 6300 | |
| 6302 | 6301 | expr_lor(); |
| 6303 | 6302 | if (tok == '?') { |
| @@ -6320,7 +6319,6 @@ static void expr_cond(void) · 16 unmodified lines | ||
| 6320 | 6319 | tt = gvtst(0, 0); |
| 6321 | 6320 | } |
| 6322 | 6321 | |
| 6323 | − ncw_prev = nocode_wanted; | |
| 6324 | 6322 | if (c == 0) |
| 6325 | 6323 | nocode_wanted++; |
| 6326 | 6324 | if (!g) |
| @@ -6339,7 +6337,8 @@ static void expr_cond(void) · 12 unmodified lines | ||
| 6339 | 6337 | } else |
| 6340 | 6338 | u = 0; |
| 6341 | 6339 | |
| 6342 | − nocode_wanted = ncw_prev; | |
| 6340 | + if (c == 0) | |
| 6341 | + nocode_wanted--; | |
| 6343 | 6342 | if (c == 1) |
| 6344 | 6343 | nocode_wanted++; |
| 6345 | 6344 | skip(':'); |
| @@ -6356,7 +6355,6 @@ static void expr_cond(void) · 10 unmodified lines | ||
| 6356 | 6355 | /* combine jump targets of 2nd op with VT_CMP of 1st op */ |
| 6357 | 6356 | gvtst_set(0, t1); |
| 6358 | 6357 | gvtst_set(1, t2); |
| 6359 | − nocode_wanted = ncw_prev; | |
| 6360 | 6358 | // tcc_warning("two conditions expr_cond"); |
| 6361 | 6359 | return; |
| 6362 | 6360 | } |
| @@ -6394,7 +6392,8 @@ static void expr_cond(void) · 31 unmodified lines | ||
| 6394 | 6392 | tt = gjmp(0); |
| 6395 | 6393 | } |
| 6396 | 6394 | gsym(u); |
| 6397 | − nocode_wanted = ncw_prev; | |
| 6395 | + if (c == 1) | |
| 6396 | + nocode_wanted--; | |
| 6398 | 6397 | |
| 6399 | 6398 | /* this is horrible, but we must also convert first |
| 6400 | 6399 | operand */ |
| @@ -39,6 +39,17 @@ static int getme(struct condstruct* s, int i) · 38 unmodified lines | ||
| 39 | 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 | 53 | int main() |
| 43 | 54 | { |
| 44 | 55 | int Count; |
| @@ -73,6 +84,8 @@ int main() · 28 unmodified lines | ||
| 73 | 84 | //0 ? a : 0.0; |
| 74 | 85 | } |
| 75 | 86 | |
| 87 | + constantcond(); | |
| 88 | + | |
| 76 | 89 | |
| 77 | 90 | return 0; |
| 78 | 91 | } |
| @@ -10,3 +10,4 @@ · 9 unmodified lines | ||
| 10 | 10 | 24 |
| 11 | 11 | 27 |
| 12 | 12 | 152 |
| 13 | +okay | |