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| author | Mike Pall <mike> | 2022-12-22 00:03:06 +0100 |
|---|---|---|
| committer | Mike Pall <mike> | 2022-12-22 00:03:06 +0100 |
| commit | 8a5e398c52c7f8ca3e1a0e574cc2ba38224b759b (patch) | |
| tree | dae089564f58db2963bae8e3530c1faae104cc61 /src/lj_cparse.c | |
| parent | b2791179ef96d652d00d78d2a8780af690537f6a (diff) | |
| download | luajit-8a5e398c52c7f8ca3e1a0e574cc2ba38224b759b.tar.gz luajit-8a5e398c52c7f8ca3e1a0e574cc2ba38224b759b.tar.bz2 luajit-8a5e398c52c7f8ca3e1a0e574cc2ba38224b759b.zip | |
Avoid negation of signed integers in C that may hold INT*_MIN.
Reported by minoki.
Recent C compilers 'take advantage' of the undefined behavior.
This completely changes the meaning of expressions like (k == -k).
Diffstat (limited to 'src/lj_cparse.c')
| -rw-r--r-- | src/lj_cparse.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/lj_cparse.c b/src/lj_cparse.c index df85d23b..8c681c56 100644 --- a/src/lj_cparse.c +++ b/src/lj_cparse.c | |||
| @@ -477,7 +477,7 @@ static void cp_expr_prefix(CPState *cp, CPValue *k) | |||
| 477 | } else if (cp_opt(cp, '+')) { | 477 | } else if (cp_opt(cp, '+')) { |
| 478 | cp_expr_unary(cp, k); /* Nothing to do (well, integer promotion). */ | 478 | cp_expr_unary(cp, k); /* Nothing to do (well, integer promotion). */ |
| 479 | } else if (cp_opt(cp, '-')) { | 479 | } else if (cp_opt(cp, '-')) { |
| 480 | cp_expr_unary(cp, k); k->i32 = -k->i32; | 480 | cp_expr_unary(cp, k); k->i32 = (int32_t)(~(uint32_t)k->i32+1); |
| 481 | } else if (cp_opt(cp, '~')) { | 481 | } else if (cp_opt(cp, '~')) { |
| 482 | cp_expr_unary(cp, k); k->i32 = ~k->i32; | 482 | cp_expr_unary(cp, k); k->i32 = ~k->i32; |
| 483 | } else if (cp_opt(cp, '!')) { | 483 | } else if (cp_opt(cp, '!')) { |