Build warnings on Windows

[SteveRussell33]

[21/140] Building CXX object lib/CMakeFiles/elements.dir/src/element/status_bar.cpp.obj
C:/_Projects/C++/Elements/lib/src/element/status_bar.cpp: In constructor 'cycfi::elements::busy_bar_base::busy_bar_base(double, double)':
C:/_Projects/C++/Elements/lib/src/element/status_bar.cpp:98:23: warning: operation on '((cycfi::elements::busy_bar_base*)this)->cycfi::elements::busy_bar_base::_status' may be undefined [-Wsequence-point]
   98 |     , _status{_status = -1 * _animation_width}
      |               ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
[51/140] Building CXX object lib/CMakeFiles/elements.dir/host/windows/base_view.cpp.obj
C:/_Projects/C++/Elements/lib/host/windows/base_view.cpp: In function 'void cycfi::elements::{anonymous}::on_scroll(HWND, view_info*, LPARAM, cycfi::elements::point)':
C:/_Projects/C++/Elements/lib/host/windows/base_view.cpp:340:34: warning: suggest parentheses around comparison in operand of '!=' [-Wparentheses]
  340 |             (info->_scroll_dir.x > 0 != dir.x > 0) ||
      |              ~~~~~~~~~~~~~~~~~~~~^~~
C:/_Projects/C++/Elements/lib/host/windows/base_view.cpp:341:34: warning: suggest parentheses around comparison in operand of '!=' [-Wparentheses]
  341 |             (info->_scroll_dir.y > 0 != dir.y > 0)
      |              ~~~~~~~~~~~~~~~~~~~~^~~
C:/_Projects/C++/Elements/lib/host/windows/base_view.cpp: In function 'HWND__* cycfi::elements::{anonymous}::make_window(cycfi::elements::base_view*, cycfi::elements::host_window_handle, RECT)':
C:/_Projects/C++/Elements/lib/host/windows/base_view.cpp:534:47: warning: missing initializer for member 'cycfi::elements::{anonymous}::view_info::_scroll_dir' [-Wmissing-field-initializers]
  534 |          view_info* info = new view_info{_this};
      |                                               ^
[53/140] Building CXX object lib/CMakeFiles/elements.dir/host/windows/drag_and_drop.cpp.obj
C:/_Projects/C++/Elements/lib/host/windows/drag_and_drop.cpp: In member function 'virtual ULONG DropTarget::Release()':
C:/_Projects/C++/Elements/lib/host/windows/drag_and_drop.cpp:55:7: warning: deleting object of polymorphic class type 'DropTarget' which has non-virtual destructor might cause undefined behavior [-Wdelete-non-virtual-dtor]
   55 |       delete this;
      |       ^~~~~~~~~~~

[djowel]

These are all safe to ignore. But if you care, feel free to prepare a PR with warning suppression :

#pragma warning(push)
#pragma warning(disable : XXXX) // Replace XXXX with MSVC warning number

// Code that triggers warning

#pragma warning(pop)

making sure other compilers are not affected.

[SteveRussell33]

Are you sure about using suppressions? I'm compiling this using GCC with MinGW not MSVC.
Using the instruction from https://cycfi.github.io/elements/elements/skia_2024/setup.html#_install_cmake_3 although selecting gtk3 fails on Windows as it's for Linux. I got cmake to output Ninja files for the build.

[djowel]

Are you sure about using suppressions?

Yes. Compilers tend to be too patronizing at times. This falls under the category of we know what we're doing :-)

Love to hear your thoughts if you disagree.

I'm compiling this using GCC with MinGW not MSVC.

Using the instruction from https://cycfi.github.io/elements/elements/skia_2024/setup.html#_install_cmake_3 although selecting gtk3 fails on Windows as it's for Linux. I got cmake to output Ninja files for the build.

Oh, OK. GCC then. If you are an expert on MinGW+WIN32, this is an area that I do not have much support for, Contributions welcome.

[djowel]

Are you sure about using suppressions?

Yes. Compilers tend to be too patronizing at times. This falls under the category of we know what we're doing :-)

Love to hear your thoughts if you disagree.

Oh, I'm OK with parens if that's what you mean.

[djowel]

warning: missing initializer for member 'cycfi::elements::{anonymous}::view_info::_scroll_dir' [-Wmissing-field-initializers]
534 | view_info* info = new view_info{_this};

Ah this better needs to be fixed. Sorry for the noise haha :-)

[SteveRussell33]

No problem, happy to help. I'll submit a PR with some fixes once I've tested (cough played around) some more!