Fix bug segfault/other memory bugs when concatenating string literals and list literals#18
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Overview
I have found that
print ("abcd" "efg" 1)crashes Harmony with a cryptic segfault instead of a graceful error. This is related to the string literal+string literal or list literal+list literal concatenation in ops.c/do_Load.Changes Made
When checking that the values after the first string are also strings, the code in
ops.c/do_Loaduses the wrong index variable. So I think the fix is just changingktoiin two different places (since this bug also affected list literal concatenation).Test Coverage
I used manual testing with
print ("abcd" "efg" 1)orprint ([1, 2, 3] [4, 5, 6] 1). If the number is1it causes a segfault on my machine. If it's significantly higher it can cause a bus error or silently read memory (I think I tested this last one but I'm not actually sure).ASAN
I found it immensely helpful to be able to run
clangwith its address sanitizer (targeted towards ARM on my Mac, since I couldn't get it working for RISC). Maybe this could be useful to someone else. Please see./asanand other changes in my testing repo.