diff options
| author | Roberto Ierusalimschy <roberto@inf.puc-rio.br> | 2011-09-14 14:40:26 -0300 |
|---|---|---|
| committer | Roberto Ierusalimschy <roberto@inf.puc-rio.br> | 2011-09-14 14:40:26 -0300 |
| commit | 500336efd087c02d663797e6d1c256f65e281f05 (patch) | |
| tree | d530000b29755ee169a9b94bbeb7d5e41b870397 /lparser.c | |
| parent | 5ea8f108e123317b27b7b4b22209aab19d781605 (diff) | |
| download | lua-500336efd087c02d663797e6d1c256f65e281f05.tar.gz lua-500336efd087c02d663797e6d1c256f65e281f05.tar.bz2 lua-500336efd087c02d663797e6d1c256f65e281f05.zip | |
small bug in if-goto optimization: block must be closed ('leaveblock')
*before* the jump out ('escapelist')
Diffstat (limited to 'lparser.c')
| -rw-r--r-- | lparser.c | 13 |
1 files changed, 8 insertions, 5 deletions
| @@ -1,5 +1,5 @@ | |||
| 1 | /* | 1 | /* |
| 2 | ** $Id: lparser.c,v 2.117 2011/08/25 13:45:24 roberto Exp roberto $ | 2 | ** $Id: lparser.c,v 2.118 2011/08/30 16:38:58 roberto Exp roberto $ |
| 3 | ** Lua Parser | 3 | ** Lua Parser |
| 4 | ** See Copyright Notice in lua.h | 4 | ** See Copyright Notice in lua.h |
| 5 | */ | 5 | */ |
| @@ -1376,27 +1376,30 @@ static void test_then_block (LexState *ls, int *escapelist) { | |||
| 1376 | expdesc v; | 1376 | expdesc v; |
| 1377 | int jf; /* instruction to skip 'then' code (if condition is false) */ | 1377 | int jf; /* instruction to skip 'then' code (if condition is false) */ |
| 1378 | luaX_next(ls); /* skip IF or ELSEIF */ | 1378 | luaX_next(ls); /* skip IF or ELSEIF */ |
| 1379 | enterblock(fs, &bl, 0); | ||
| 1380 | expr(ls, &v); /* read condition */ | 1379 | expr(ls, &v); /* read condition */ |
| 1381 | checknext(ls, TK_THEN); | 1380 | checknext(ls, TK_THEN); |
| 1382 | if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) { | 1381 | if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) { |
| 1383 | luaK_goiffalse(ls->fs, &v); /* will jump to label if condition is true */ | 1382 | luaK_goiffalse(ls->fs, &v); /* will jump to label if condition is true */ |
| 1383 | enterblock(fs, &bl, 0); /* must enter block before 'goto' */ | ||
| 1384 | gotostat(ls, v.t); /* handle goto/break */ | 1384 | gotostat(ls, v.t); /* handle goto/break */ |
| 1385 | if (block_follow(ls, 0)) /* no more code after 'goto'? */ | 1385 | if (block_follow(ls, 0)) { /* 'goto' is the entire block? */ |
| 1386 | goto leave; /* that is it */ | 1386 | leaveblock(fs); |
| 1387 | return; /* and that is it */ | ||
| 1388 | } | ||
| 1387 | else /* must skip over 'then' part if condition is false */ | 1389 | else /* must skip over 'then' part if condition is false */ |
| 1388 | jf = luaK_jump(fs); | 1390 | jf = luaK_jump(fs); |
| 1389 | } | 1391 | } |
| 1390 | else { /* regular case (not goto/break) */ | 1392 | else { /* regular case (not goto/break) */ |
| 1391 | luaK_goiftrue(ls->fs, &v); /* skip over block if condition is false */ | 1393 | luaK_goiftrue(ls->fs, &v); /* skip over block if condition is false */ |
| 1394 | enterblock(fs, &bl, 0); | ||
| 1392 | jf = v.f; | 1395 | jf = v.f; |
| 1393 | } | 1396 | } |
| 1394 | statlist(ls); /* `then' part */ | 1397 | statlist(ls); /* `then' part */ |
| 1398 | leaveblock(fs); | ||
| 1395 | if (ls->t.token == TK_ELSE || | 1399 | if (ls->t.token == TK_ELSE || |
| 1396 | ls->t.token == TK_ELSEIF) /* followed by 'else'/'elseif'? */ | 1400 | ls->t.token == TK_ELSEIF) /* followed by 'else'/'elseif'? */ |
| 1397 | luaK_concat(fs, escapelist, luaK_jump(fs)); /* must jump over it */ | 1401 | luaK_concat(fs, escapelist, luaK_jump(fs)); /* must jump over it */ |
| 1398 | luaK_patchtohere(fs, jf); | 1402 | luaK_patchtohere(fs, jf); |
| 1399 | leave: leaveblock(fs); | ||
| 1400 | } | 1403 | } |
| 1401 | 1404 | ||
| 1402 | 1405 | ||