From 9b85ffa5a760e53536762bf6cdf402c90ae9ceb7 Mon Sep 17 00:00:00 2001 From: Yukihiro Matsumoto Date: Thu, 1 Nov 2012 05:54:53 +0900 Subject: OP_ADDI/OP_SUBI should handle integer overflow; close #518 --- src/vm.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/src/vm.c b/src/vm.c index 120e0d4c0..953863a0b 100644 --- a/src/vm.c +++ b/src/vm.c @@ -1444,7 +1444,18 @@ mrb_run(mrb_state *mrb, struct RProc *proc, mrb_value self) /* need to check if + is overridden */ switch (mrb_type(regs[a])) { case MRB_TT_FIXNUM: - regs[a].attr_i += GETARG_C(i); + { + mrb_int x = regs[a].attr_i; + mrb_int y = GETARG_C(i); + mrb_int z = x + y; + + if (((x < 0) ^ (y < 0)) == 0 && (x < 0) != (z < 0)) { + /* integer overflow */ + SET_FLT_VALUE(regs[a], (mrb_float)x + (mrb_float)y); + break; + } + regs[a].attr_i = z; + } break; case MRB_TT_FLOAT: regs[a].attr_f += GETARG_C(i); @@ -1464,7 +1475,18 @@ mrb_run(mrb_state *mrb, struct RProc *proc, mrb_value self) /* need to check if + is overridden */ switch (mrb_type(regs[a])) { case MRB_TT_FIXNUM: - regs[a].attr_i -= GETARG_C(i); + { + mrb_int x = regs[a].attr_i; + mrb_int y = GETARG_C(i); + mrb_int z = x - y; + + if (((x < 0) ^ (y < 0)) == 0 && (x < 0) != (z < 0)) { + /* integer overflow */ + SET_FLT_VALUE(regs[a], (mrb_float)x - (mrb_float)y); + break; + } + regs[a].attr_i = z; + } break; case MRB_TT_FLOAT: regs[a].attr_f -= GETARG_C(i); -- cgit v1.2.3