In Bryan Hundven's patch 1ad439907 from 2010, the author added -lstdc++
and -lm to the host gcc build's LDFLAGS, because at the time the linker
did not correctly include these libraries causing the build to fail.
In modern builds, this causes a problem for canadian gcc builds where
the host machine is mingw32-w64 Windows.
Within the gcc build there is the liblto_plugin module. On Windows this
must be built as the "liblto_plugin.dll" dynamic library. However,
libtool cannot produce a dynamic library unless every library dependency
is also a dynamic library, and falls back to producing a libstdc++.a
static library. liblto_plugin does not require libstdc++ - it
does not contain any C++ code, and the dependency would usually be
elided by the linker.
Unfortunately, in this case, crosstool-ng will never build a
libstdc++.dll dynamic library - only a libstdc++.a static library.
Therefore, there will never be a dynamic library version of stdc++ for
libtool to load and then discard.
This patch corrects the issue by removing "-lstdc++" from LDFLAGS,
because modern versions of gcc are able to correctly include libstdc++
where necessary. It also remove "-lm" for similar reasons.
Signed-off-by: Joel Holdsworth <jholdsworth@nvidia.com>
da1ffd0412