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fix off-by-one error in DynamicIndexedChoice (#1210)

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This commit is contained in:
Mark Thom
2022-01-13 18:06:44 -07:00
parent 3b8afce7c7
commit c6d23f9a0b
1 changed files with 8 additions and 10 deletions
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18
src/machine/dispatch.rs
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@@ -266,7 +266,7 @@ impl Machine {
}
}
pub(super) fn find_living_dynamic(&self, oi: u32, mut ii: u32) -> Option<(usize, u32, u32, usize, bool)> {
pub(super) fn find_living_dynamic(&self, oi: u32, mut ii: u32) -> Option<(usize, u32, u32, bool)> {
let p = self.machine_st.p;
let indexed_choice_instrs = match &self.code[p] {
@@ -287,10 +287,8 @@ impl Machine {
death,
next_or_fail,
) => {
let len = indexed_choice_instrs.len();
if birth < self.machine_st.cc && Death::Finite(self.machine_st.cc) <= death {
return Some((offset, oi, ii, len, next_or_fail.is_next()));
return Some((offset, oi, ii, next_or_fail.is_next()));
} else {
ii += 1;
}
@@ -3039,7 +3037,7 @@ impl Machine {
let p = self.machine_st.p;
match self.find_living_dynamic(self.machine_st.oip, self.machine_st.iip) {
Some((offset, oi, ii, _, is_next_clause)) => {
Some((offset, oi, ii, is_next_clause)) => {
self.machine_st.p = p;
self.machine_st.oip = oi;
self.machine_st.iip = ii;
@@ -3060,9 +3058,9 @@ impl Machine {
self.machine_st.registers[self.machine_st.num_of_args + 1] =
fixnum_as_cell!(Fixnum::build_with(self.machine_st.cc as i64));
self.machine_st.num_of_args += 2;
self.machine_st.num_of_args += 1;
self.machine_st.indexed_try(offset);
self.machine_st.num_of_args -= 2;
self.machine_st.num_of_args -= 1;
}
None => {
self.machine_st.p = p + offset;
@@ -3081,16 +3079,16 @@ impl Machine {
.num_cells;
self.machine_st.cc = cell_as_fixnum!(
self.machine_st.stack[stack_loc!(OrFrame, b, n-2)]
self.machine_st.stack[stack_loc!(OrFrame, b, n-1)]
).get_num() as usize;
if is_next_clause {
match self.find_living_dynamic(self.machine_st.oip, self.machine_st.iip) {
match self.find_living_dynamic(self.machine_st.oip, self.machine_st.iip + 1) {
// if we're executing the last instruction
// of the internal block pointed to by
// self.machine_st.iip, we want trust, not retry.
// this is true iff ii + 1 < len.
Some((_,_,ii,len,_)) if (ii as usize) + 1 < len => {
Some(_) => {
self.retry(offset);
try_or_throw!(