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Fix lua failure to catch divide by zero and NaN exceptions

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I can only assume in the course of the original conversion to fixed point
math in RbLua the fact that division by zero and NaN handling was to be
caught as a graceful exception by the floating point handler was overlooked.

As a result lua doesn't handle these exceptions and instead results in a
panic on the device.

This patch fixes this handling in the lexer for compile time Inf and Nan
results and in the luavm for runtime division by zero (Inf)

I missed the runtime exception of n%0 added checks for that as well..

Change-Id: I7746c087ea93678e5875f15ec6fe3f29f26bdb31
This commit is contained in:
William Wilgus 2018-02-05 07:28:08 +01:00
parent 80bb6ccdc4
commit 9a9c7f2b7c
2 changed files with 33 additions and 8 deletions
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28
apps/plugins/lua/lvm.c
View file

@ -480,13 +480,35 @@ void luaV_execute (lua_State *L, int nexeccalls) {
continue;
}
case OP_DIV: {
arith_op(luai_numdiv, TM_DIV);
TValue *rb = RKB(i);
TValue *rc = RKC(i);
if (ttisnumber(rb) && ttisnumber(rc)) {
lua_Number nb = nvalue(rb), nc = nvalue(rc);
if (nc == 0)
luaG_typeerror(L, rc, "divide by zero");
setnvalue(ra, luai_numdiv(nb, nc));
}
else
Protect(Arith(L, ra, rb, rc, TM_DIV));
continue;
}
case OP_MOD: {
arith_op(luai_nummod, TM_MOD);
TValue *rb = RKB(i);
TValue *rc = RKC(i);
if (ttisnumber(rb) && ttisnumber(rc)) {
lua_Number nb = nvalue(rb), nc = nvalue(rc);
if (nc == 0)
luaG_typeerror(L, rc, "perform 'n%0'");
setnvalue(ra, luai_nummod(nb, nc));
}
else
Protect(Arith(L, ra, rb, rc, TM_MOD));
continue;
}
}
case OP_POW: {
arith_op(luai_numpow, TM_POW);
continue;