'hb-set.hh' build errors with MSVC

[johne53]

I'm seeing lots of errors when trying to build harfbuzz (from git master) with MSVC. They relate to some recent changes in 'src/hb-set.hh' (approx line 370) where 'sizeof (pages.arrayZ()[0])' got changed to 'sizeof (pages[0])'.

A similar error occurs on the following line - where 'sizeof (page_map.arrayZ()[0])' got changed to 'sizeof (page_map[0])'. This is the general form for each error:-

harfbuzz\src\hb-set.hh(378) : error C2666: 'hb_vector_t<Type,StaticSize>::operator []' : 4 overloads have similar conversions
: could be 'const hb_set_t::page_t &hb_vector_t<Type,StaticSize>::operator [](unsigned int) const'
: or 'hb_set_t::page_t &hb_vector_t<Type,StaticSize>::operator [](unsigned int)'
: or 'built-in C++ operator[(T *, int)'
: or 'built-in C++ operator[(const T *, int)'

I'm also seeing "multiple overload" errors in other places - e.g. for DEFINE_SIZE_ARRAY and its variants. As it happens, this project needs to get built with MSVC2008 - although these particular errors look like they'd occur, even with the more recent versions.

[behdad]

John. If you want a fix, I need all different instances of the error.

[johne53]

Hi Behdad - I haven't loaded your new commit yet (if it only deals with warnings) but here are the errors I see from just compiling 'hb-aat-layout.cc' (the remaining source files seem to produce the same errors):-

(line 378 - hb-set.hh) - memcpy (pages, other->pages, count * sizeof (pages[0]));
error C2666: 'hb_vector_t<Type,StaticSize>::operator []' : 4 overloads have similar conversions
: could be 'const hb_set_t::page_t &hb_vector_t<Type,StaticSize>::operator [](unsigned int) const'
: or 'hb_set_t::page_t &hb_vector_t<Type,StaticSize>::operator [](unsigned int)'
: or 'built-in C++ operator[(T *, int)'
: or 'built-in C++ operator[(const T *, int)'

(line 379 - hb-set.hh) - memcpy (page_map, other->page_map, count * sizeof (page_map[0]));
error C2666: 'hb_vector_t<Type,StaticSize>::operator []' : 4 overloads have similar conversions
: could be 'const hb_set_t::page_map_t &hb_vector_t<Type,StaticSize>::operator [](unsigned int) const'
: or 'hb_set_t::page_map_t &hb_vector_t<Type,StaticSize>::operator [](unsigned int)'
: or 'built-in C++ operator[(T *, int)'
: or 'built-in C++ operator[(const T *, int)'

(line 663 - hb-set.hh) - return page_map[i].major * page_t::PAGE_BITS + page_at (i).get_max ();
error C2666: 'hb_vector_t<Type,StaticSize>::operator []' : 2 overloads have similar conversions
: could be 'const hb_set_t::page_map_t &hb_vector_t<Type,StaticSize>::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 681 - hb-set.hh) - (page_map.len - 1 - i) * sizeof (page_map[0]))
error C2666: 'hb_vector_t<Type,StaticSize>::operator []' : 4 overloads have similar conversions
: could be 'const hb_set_t::page_map_t &hb_vector_t<Type,StaticSize>::operator [](unsigned int) const'
: or 'hb_set_t::page_map_t &hb_vector_t<Type,StaticSize>::operator [](unsigned int)'
: or 'built-in C++ operator[(T *, int)'
: or 'built-in C++ operator[(const T *, int)'

(line 1520 - hb-ot-layout-common.hh) - DEFINE_SIZE_ARRAY (4, axesZ);
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::VarRegionAxis &OT::UnsizedArrayOf::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 1579 - hb-ot-layout-common.hh) - DEFINE_SIZE_ARRAY2 (6, regionIndices, bytesX);
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::HBUINT8 &OT::UnsizedArrayOf::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 1895- hb-ot-layout-common.hh) - DEFINE_SIZE_ARRAY (6, deltaValueZ);
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::HBUINT16 &OT::UnsizedArrayOf::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 1350 - hb-ot-layout-gsubgpos.hh) - return_trace (inputCount.sanitize (c) &&
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::HBUINT16 &OT::UnsizedArrayOf::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 1369 - hb-ot-layout-gsubgpos.hh) - DEFINE_SIZE_ARRAY (4, inputZ);
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::HBUINT16 &OT::UnsizedArrayOf::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 1675 - hb-ot-layout-gsubgpos.hh) - if (!(this+coverageZ[0]).intersects (glyphs))
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::HBUINT16 &OT::UnsizedArrayOf::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 1690 - hb-ot-layout-gsubgpos.hh) - if (!(this+coverageZ[0]).intersects (c->glyphs))
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::OffsetTo &OT::UnsizedArrayOf<OT::OffsetTo>::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 1707 - hb-ot-layout-gsubgpos.hh) - (this+coverageZ[0]).add_coverage (c->input)
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::OffsetTo &OT::UnsizedArrayOf<OT::OffsetTo>::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 1734 - hb-ot-layout-gsubgpos.hh) - { return this+coverageZ[0]; }
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::OffsetTo &OT::UnsizedArrayOf<OT::OffsetTo>::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 1739 - hb-ot-layout-gsubgpos.hh) - unsigned int index = (this+coverageZ[0]).get_coverage (c->buffer->cur().codepoint);
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::OffsetTo &OT::UnsizedArrayOf<OT::OffsetTo>::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 1782 - hb-ot-layout-gsubgpos.hh) - DEFINE_SIZE_ARRAY (6, coverageZ);
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::OffsetTo &OT::UnsizedArrayOf<OT::OffsetTo>::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 399 - hb-ot-layout-gpos-table.hh) - DEFINE_SIZE_ARRAY (2, matrixZ);
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const OT::OffsetTo &OT::UnsizedArrayOf<OT::OffsetTo>::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 165 - hb-aat-layout-trak-table.hh) - DEFINE_SIZE_ARRAY (8, trackTable)
error C2666: 'OT::UnsizedArrayOf::operator []' : 2 overloads have similar conversions
: could be 'const AAT::TrackTableEntry &OT::UnsizedArrayOf::operator [](unsigned int) const'
: or 'built-in C++ operator[(const T *, int)'

(line 165 - hb-aat-layout-trak-table.hh) - DEFINE_SIZE_ARRAY (8, trackTable)
error C2228: left of '.static_size' must have class/struct/union

[johne53]

Hi Behdad - I just updated from git and your changes do seem to have fixed the errors (in 'hb-set.hh') at lines 378 and 379. So you probably need to do something similar in the other cases. Thanks for helping with this.

[behdad]

Okay, give it another try.

[johne53]

Okay, there seem to be problems now with the use of 'static_size' in various places. The most common ones seem to be in the macro DEFINE_SIZE_ARRAY. Wherever it gets used I see an error like this:-

error C2228: left of '.static_size' must have class/struct/union : type is 'const T'

I'm seeing similar issues with the use of 'coverageZ' which gives similar errors when it exposes members like 'sanitize' . 'get_coverage' / 'add_coverage' etc.

Maybe I should go back to the previous version and just accept that Harfbuzz won't build for me any more..?

[behdad]

error C2228: left of '.static_size' must have class/struct/union : type is 'const T'

Okay, this is becoming bizarre. What was the last version you could compile?

I'm seeing similar issues with the use of 'coverageZ' which gives similar errors when it exposes members like 'sanitize' . 'get_coverage' / 'add_coverage' etc.

Please paste error message.

[johne53]

The last time Harfbuzz built successfully was only about 3 weeks ago (Ebrahim's commit #03e144135b from 18th Oct).

To be honest, these feel like multiple instances of a small number of problems. This isn't a comprehensive list but as some examples, I'm seeing errors like these, relating to DEFINE_SIZE_ARRAY:-

(line 1520 - hb-ot-layout-common.hh) - DEFINE_SIZE_ARRAY (4, axesZ);
error C2228: left of '.static_size' must have class/struct/union
: type is 'const T'

(line 1579 - hb-ot-layout-common.hh) - DEFINE_SIZE_ARRAY2 (6, regionIndices, bytesX);
error C2228: left of '.static_size' must have class/struct/union
: type is 'const T'

(line 1369 - hb-ot-layout-gsubgpos.hh) - DEFINE_SIZE_ARRAY (4, inputZ);
error C2228: left of '.static_size' must have class/struct/union
: type is 'const T'

*** and several more like the above - plus errors like these (relating to 'coverageZ') ***

(line 1675 - hb-ot-layout-gsubgpos.hh) - if (!(this+coverageZ[0]).intersects (glyphs))
error C2228: left of '.intersects' must have class/struct/union
: type is 'const T'

(line 1707 - hb-ot-layout-gsubgpos.hh) - (this+coverageZ[0]).add_coverage (c->input);
error C2228: left of '.add_coverage' must have class/struct/union
: type is 'const T'

(line 1739 - hb-ot-layout-gsubgpos.hh) - unsigned int index = (this+coverageZ[0]).get_coverage (c->buffer->cur().codepoint);
error C2228: left of '.get_coverage' must have class/struct/union
: type is 'const T'

(line 1765 - hb-ot-layout-gsubgpos.hh) - if (!coverageZ[i].sanitize (c, this)) return_trace (false);
error C2228: left of '.sanitize' must have class/struct/union
: type is 'const T'

[behdad]

Such bizarre errors. I'm out of ideas. Either play with DEFINE_SIZE_ARRAY, diff it with the last good version, change, see what works (does removing the paranthesis around array help?!!! Not that that would be safe...), or bisect and find which change introduced it. That compiler seems to be so b0rked.

[johne53]

Yes it does seem strange. From a superficial glance, the lines which are failing don't seem to have changed between the working version and the non-working version. I'll try git bisect and see if that reveals anything.

[johne53]

Okay, the problematic commit seems to be commit #955aa56b11 from 26th Oct 2018 and it's entitled "[vector] Make it act more like pointer". I can't say if that's responsible for all the problems I'm seeing but that's definitely where they began.

Can I ask an obvious question..? Does Harfbuzz need C++11? (because obviously, that wouldn't be available as far back as VS2008).

[johne53]

And this is only a hunch - but I've a feeling the remaining problems originate in the changes made to 'hb-open-type.hh' and 'hb-dsalgs.hh' between 31st Oct and 5th Nov (I'm referring to the changes that have now affected 'DEFINE_SIZE_ARRAY'). Those ones look quite similar to the changes I just reported in 'hb-vector.hh'.