The importance of glibc makes it worthwhile to provide debug
symbols. However, this revealed an issue with separateDebugInfo: it
was indiscriminately adding --build-id to all ld invocations, while in
fact it should only do that for final links. Glibc also uses non-final
("relocatable") links, leading to subsequent failure to apply a build
ID ("Cannot create .note.gnu.build-id section, --build-id
ignored"). So now ld-wrapper.sh only passes --build-id for final
links.
Otherwise, when building glibc and other packages, the "strip" from
bootstrapTools is used, which doesn't recognise some tags produced by
the newer "ld" from binutils.
The ld-wrapper.sh script calls `readlink` in some circumstances. We need
to ensure that this is the `readlink` from the `coreutils` package so
that flag support is as expected.
This is accomplished by explicitly setting PATH at the top of each shell
script.
Without doing this, the following happens with a trivial `main.c`:
```
nix-env -f "<nixpkgs>" -iA pkgs.clang
$ clang main.c -L /nix/../nix/store/2ankvagznq062x1gifpxwkk7fp3xwy63-xnu-2422.115.4/Library -o a.out
readlink: illegal option -- f
usage: readlink [-n] [file ...]
```
The key element is the `..` in the path supplied to the linker via a
`-L` flag. With this patch, the above invocation works correctly on
darwin, whose native `/usr/bin/readlink` does not support the `-f` flag.
The explicit path also ensures that the `grep` called by `cc-wrapper.sh`
is the one from Nix.
Fixes#6447
This reverts d927da8dae. Having a copy
of gcc-wrapper/setup-hook.sh is bad for maintainability - it had
already started to diverge. Also, gccStdInc gave a nix-env conflict
with the standard gcc. And it wasn't actually used in Nixpkgs.
Instead, if you really need to change "-isystem" to "-I", you can now
set ccIncludeFlag to "-I".
- Add a conditional flag for the c++ std lib
- Build binaries that get linked by our own dyld (someday)
- Automatically add framework directories in the setup hook
