cc-wrapper: Account for NIX_LDFLAGS and NIX_CFLAGS_LINK in linkType

Without this, pkgsStatic.pkgsLLVM.hello fails with segfaulting binaries
because of the issue described at [0].

In summary, llvm's linker has a different behaviour to GCC's when
supplied with both -static and -Wl,-dynamic-linker=...; GCC copes with
it, but LLVM produces a binary which segfaults on startup. It appears to
be necessary to omit the dynamic linker in this case.

nixpkgs' static adaptor passes -static via NIX_CFLAGS_LINK which was not
accounted for prior to this commit in the checkLinkType logic. For good
measure I put the other NIX_ flags affecting link in the same logic.

Additionally, $NIX_CFLAGS_LINK_@suffixSalt@ is not available until later
than it was originally set, so set $linkType close to its point of use.
I checked for earlier uses by studying the shell trace output and
couldn't find any.

[0] https://github.com/NixOS/nixpkgs/issues/111010#issuecomment-1536424163

Signed-off-by: Peter Waller <p@pwaller.net>

0 files changed, 0 insertions, 0 deletions