Attachment 253581 Details for Bug 281516 – graphics/libemf: fix build with libc++ 19

[patch] graphics/libemf: fix build with libc++ 19

graphics__libemf-fix-libcxx19-build-1.diff (text/plain), 2.57 KB, created by Dimitry Andric on 2024-09-15 11:55:54 UTC

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Creator: Dimitry Andric

Created: 2024-09-15 11:55:54 UTC

Size: 2.57 KB

patch

obsolete

>commit 26a03177140023fc00b89c77b18872bda8041060
>Author: Dimitry Andric <dim@FreeBSD.org>
>Date:   2024-09-15T13:55:03+02:00
>
>    graphics/libemf: fix build with libc++ 19
>    
>    As noted in the libc++ 19 release notes [1], std::char_traits<> is now
>    only provided for char, char8_t, char16_t, char32_t and wchar_t, and any
>    instantiation for other types will fail.
>    
>    This causes graphics/libemf to fail to compile with clang 19 and libc++
>    19, resulting in errors similar to:
>    
>      /usr/include/c++/v1/string:820:42: error: implicit instantiation of undefined template 'std::char_traits<unsigned short>'
>        820 |   static_assert(is_same<_CharT, typename traits_type::char_type>::value,
>            |                                          ^
>      libemf.cpp:982:30: note: in instantiation of template class 'std::basic_string<unsigned short>' requested here
>        982 |     std::basic_string<WCHAR> filename_w( filename, filename + filename_count );
>            |                              ^
>      /usr/include/c++/v1/__fwd/string.h:23:29: note: template is declared here
>         23 | struct _LIBCPP_TEMPLATE_VIS char_traits;
>            |                             ^
>    
>    libemf should really use char16_t for its 16-bit character type, but the
>    code is full of Windows assumptions that WCHAR is unsigned short. Since
>    std::basic_string<unsigned short> is no longer available, use
>    std::basic_string<char16_t> instead, and cast the result to the
>    appropriate type for GetEnhMetaFileW().
>    
>    [1] https://libcxx.llvm.org/ReleaseNotes/19.html#deprecations-and-removals
>    
>    PR:             281516
>    MFH:            2024Q3
>
>diff --git a/graphics/libemf/files/patch-libemf_libemf.cpp b/graphics/libemf/files/patch-libemf_libemf.cpp
>index b0da3b4bbe53..e0368f114e08 100644
>--- a/graphics/libemf/files/patch-libemf_libemf.cpp
>+++ b/graphics/libemf/files/patch-libemf_libemf.cpp
>@@ -1,4 +1,4 @@
>---- libemf/libemf.cpp.orig	2021-11-01 12:21:53 UTC
>+--- libemf/libemf.cpp.orig	2020-06-07 13:10:20 UTC
> +++ libemf/libemf.cpp
> @@ -72,8 +72,7 @@ namespace EMF {
>      if ( not bigEndian() ) {
>@@ -10,3 +10,15 @@
>    }
>  
>    /*!
>+@@ -980,9 +979,9 @@ extern "C" {
>+ 
>+     int filename_count = ::strlen( filename );
>+ 
>+-    std::basic_string<WCHAR> filename_w( filename, filename + filename_count );
>++    std::basic_string<char16_t> filename_w( filename, filename + filename_count );
>+ 
>+-    HENHMETAFILE handle =  GetEnhMetaFileW( filename_w.c_str() );
>++    HENHMETAFILE handle =  GetEnhMetaFileW( reinterpret_cast<LPCWSTR>(filename_w.c_str()) );
>+ 
>+     return handle;
>+   }

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Attachments on bug 281516: 253581