Mercurial > octave
changeset 32401:1156548e6211
Fix making id undefined in zero iteration for-loops in VM with wide slots. (bug #64749)
E.g.:
for i = 1:0
end
Would clear the wrong id instead of 'i' if 'i' had a slot number over 255 due to
reading a short as a char.
* libinterp/parse-tree/pt-bytecode-vm.cc: Proper byte shifting of shorts
| author | Petter T. <petter.vilhelm@gmail.com> |
|---|---|
| date | Sun, 08 Oct 2023 22:25:06 +0200 |
| parents | 3f48081aa034 |
| children | 7da49c0da993 |
| files | libinterp/parse-tree/pt-bytecode-vm.cc test/compile/bytecode_misc.m |
| diffstat | 2 files changed, 15 insertions(+), 2 deletions(-) [+] |
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--- a/libinterp/parse-tree/pt-bytecode-vm.cc Wed Oct 11 18:46:51 2023 +0200 +++ b/libinterp/parse-tree/pt-bytecode-vm.cc Sun Oct 08 22:25:06 2023 +0200 @@ -2731,10 +2731,17 @@ { // Slot from the for_cond that always follow a for_setup int slot; + // The next opcode is in arg0, and is either WIDE or FOR_COND if (arg0 == static_cast<int> (INSTR::WIDE)) - slot = ip[1]; + { + // Byte layout: ip[-2]:FOR_SETUP, ip[-1]:WIDE, ip[0]:FOR_COND, ip[1]:slot_lsb, ip[2]:slot_msb + slot = ip[1] + (ip[2] << 8); + } else - slot = ip[0]; + { + // Byte layout: ip[-2]:FOR_SETUP, ip[-1]:FOR_COND, ip[0]:slot + slot = ip[0]; + } try { octave_value &lhs_ov = bsp[slot].ov;
--- a/test/compile/bytecode_misc.m Wed Oct 11 18:46:51 2023 +0200 +++ b/test/compile/bytecode_misc.m Sun Oct 08 22:25:06 2023 +0200 @@ -127,6 +127,12 @@ assert (b == 2) end + % Bug #64749: With no iterations, FOR_SETUP writes to the wrong id with wide slots + i = 123; + for i = 1:0 + end + assert (isempty (i)); + assert (size(i) == [1 0]) % Check that a001 to a512 have to correct values for i = 1:512