[Bug libstdc++/93602] Missing reference to libiconv in 9.x libstdc++

[zvr+gcc at zvr dot gr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93602

Alexios Zavras (zvr) <zvr+gcc at zvr dot gr> changed:

           What    |Removed                     |Added
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                 CC|                            |zvr+gcc at zvr dot gr

--- Comment #14 from Alexios Zavras (zvr) <zvr+gcc at zvr dot gr> ---
I can confirm this bug also in gcc-9.3.0, gcc-10.1.0 and gcc-10.2.0.

To recap: if the system has a libiconv installed, the generated and installed
libstdc++.so depends on it.

However the compiler, when using it when compiling a C++ program, does not link
libiconv, resulting in an error:

$ g++ foo.cc
/usr/local/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../../x86_64-pc-linux-gnu/bin/ld:
/usr/local/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../../lib64/libstdc++.so:
undefined reference to `libiconv'
/usr/local/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../../x86_64-pc-linux-gnu/bin/ld:
/usr/local/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../../lib64/libstdc++.so:
undefined reference to `libiconv_close'
/usr/local/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../../x86_64-pc-linux-gnu/bin/ld:
/usr/local/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../../lib64/libstdc++.so:
undefined reference to `libiconv_open'
collect2: error: ld returned 1 exit status