Undefined Behavior Sanitizer error in hb-font.cc:579:72 - index 6 out of bounds for type <unknown> *[1]

[pedronavf]

Building harfbuzz 1.7.6 in 32 bits mode with -fsanitize=undefined and running hb-shape <any_font> --text="hello"

hb-font.cc:579:72: runtime error: index 6 out of bounds for type <unknown> *[1]

#0 0xf7df7e30 in hb_font_t::has_func(unsigned int) /home/pnavarro/test/source/harfbuzz/src/hb-font.cc:579
#1 0xf7e888d7 in hb_font_t::has_glyph_h_origin_func() /home/pnavarro/test/source/harfbuzz/src/hb-font-private.hh:175
#2 0xf7e862e7 in hb_ot_position_default /home/pnavarro/test/source/harfbuzz/src/hb-ot-shape.cc:673
#3 0xf7e87045 in hb_ot_position /home/pnavarro/test/source/harfbuzz/src/hb-ot-shape.cc:769
#4 0xf7e87e1f in hb_ot_shape_internal /home/pnavarro/test/source/harfbuzz/src/hb-ot-shape.cc:850
#5 0xf7e8821a in _hb_ot_shape /home/pnavarro/test/source/harfbuzz/src/hb-ot-shape.cc:876
#6 0xf7e07a8a in hb_shape_plan_execute /home/pnavarro/test/source/harfbuzz/src/hb-shaper-list.hh:43
#7 0xf7e06b67 in hb_shape_full /home/pnavarro/test/source/harfbuzz/src/hb-shape.cc:132
#8 0x804b5c1 in shape_options_t::shape(hb_font_t*, hb_buffer_t*, char const**) (/home/pnavarro/test/bin/hb-shape+0x804b5c1)
#9 0x804ed1a in shape_consumer_t<output_buffer_t>::consume_line(char const*, unsigned int, char const*, char const*) (/home/pnavarro/test/bin/hb-shape+0x804ed1a)
#10 0x804e7a2 in main_font_text_t<shape_consumer_t<output_buffer_t>, 2147483647, 0>::main(int, char**) (/home/pnavarro/test/bin/hb-shape+0x804e7a2)
#11 0x804a82d in main /home/pnavarro/test/source/harfbuzz/util/hb-shape.cc:162
#12 0xf720e985 in __libc_start_main (/lib/i386-linux-gnu/libc.so.6+0x18985)
#13 0x804a500  (/home/pnavarro/test/bin/hb-shape+0x804a500)

[behdad]

Those are false positives.

[pedronavf]

Should we add the UBSAN attributes to the functions so they are not instrumented?

[behdad]

Sure, feel free. I don't know how those look.

I fixed this one. But yeah, for other one.