[clang] [clang][driver] Add \<executable\>/../include/c++/v1 to include path on Darwin (PR #70817)

[Liviu Ionescu via cfe-commits]

ilg-ul wrote:

> for your use case, can you stick symlinks in to preserve that toolchain folder structure relative to the ~/tmp/clang++ symlink? i.e. make that ~/tmp/bin/clang++ -> /Users/ilg/Library/xPacks/@xpack-dev-tools/clang/15.0.7-3.1/.content/bin/clang-15 and add ~/tmp/lib -> /Users/ilg/Library/xPacks/@xpack-dev-tools/clang/15.0.7-3.1/.content/lib (and same for include).

I'm not sure I understand your proposal, but I'm afraid changing the structure of the symlinks is not possible, it is done automatically by a tool.

The example above was just to demonstrate the bug.

In the actual use case, which is inspired by the npm use case, in the project there is a folder `xpacks` with symlinks to all dependent binaries, with dual indirections, something like this:

```
ilg at wksi native-cmake-clang13-debug % ls -lAR xpacks
total 0
drwxr-xr-x  61 ilg  staff  1952 Oct 31 14:42 .bin
drwxr-xr-x   3 ilg  staff    96 Oct 31 14:42 @micro-os-plus
drwxr-xr-x   3 ilg  staff    96 Oct 31 14:42 @xpack-dev-tools

xpacks/.bin:
total 0
lrwxr-xr-x  1 ilg  staff  44 Oct 31 14:42 clang -> ../@xpack-dev-tools/clang/.content/bin/clang
lrwxr-xr-x  1 ilg  staff  46 Oct 31 14:42 clang++ -> ../@xpack-dev-tools/clang/.content/bin/clang++
lrwxr-xr-x  1 ilg  staff  50 Oct 31 14:42 clang-check -> ../@xpack-dev-tools/clang/.content/bin/clang-check
lrwxr-xr-x  1 ilg  staff  47 Oct 31 14:42 clang-cl -> ../@xpack-dev-tools/clang/.content/bin/clang-cl
lrwxr-xr-x  1 ilg  staff  48 Oct 31 14:42 clang-cpp -> ../@xpack-dev-tools/clang/.content/bin/clang-cpp
lrwxr-xr-x  1 ilg  staff  48 Oct 31 14:42 clang-doc -> ../@xpack-dev-tools/clang/.content/bin/clang-doc
lrwxr-xr-x  1 ilg  staff  51 Oct 31 14:42 clang-format -> ../@xpack-dev-tools/clang/.content/bin/clang-format
lrwxr-xr-x  1 ilg  staff  60 Oct 31 14:42 clang-offload-bundler -> ../@xpack-dev-tools/clang/.content/bin/clang-offload-bundler
lrwxr-xr-x  1 ilg  staff  60 Oct 31 14:42 clang-offload-wrapper -> ../@xpack-dev-tools/clang/.content/bin/clang-offload-wrapper
lrwxr-xr-x  1 ilg  staff  53 Oct 31 14:42 clang-refactor -> ../@xpack-dev-tools/clang/.content/bin/clang-refactor
lrwxr-xr-x  1 ilg  staff  51 Oct 31 14:42 clang-rename -> ../@xpack-dev-tools/clang/.content/bin/clang-rename
lrwxr-xr-x  1 ilg  staff  54 Oct 31 14:42 clang-scan-deps -> ../@xpack-dev-tools/clang/.content/bin/clang-scan-deps
lrwxr-xr-x  1 ilg  staff  49 Oct 31 14:42 clang-tidy -> ../@xpack-dev-tools/clang/.content/bin/clang-tidy
lrwxr-xr-x  1 ilg  staff  45 Oct 31 14:42 clangd -> ../@xpack-dev-tools/clang/.content/bin/clangd
lrwxr-xr-x  1 ilg  staff  61 Oct 31 14:42 clangd-xpc-test-client -> ../@xpack-dev-tools/clang/.content/bin/clangd-xpc-test-client
lrwxr-xr-x  1 ilg  staff  51 Oct 31 14:42 darwin-debug -> ../@xpack-dev-tools/clang/.content/bin/darwin-debug
lrwxr-xr-x  1 ilg  staff  47 Oct 31 14:42 diagtool -> ../@xpack-dev-tools/clang/.content/bin/diagtool
lrwxr-xr-x  1 ilg  staff  55 Oct 31 14:42 git-clang-format -> ../@xpack-dev-tools/clang/.content/bin/git-clang-format
lrwxr-xr-x  1 ilg  staff  47 Oct 31 14:42 hmaptool -> ../@xpack-dev-tools/clang/.content/bin/hmaptool
lrwxr-xr-x  1 ilg  staff  45 Oct 31 14:42 ld.lld -> ../@xpack-dev-tools/clang/.content/bin/ld.lld
lrwxr-xr-x  1 ilg  staff  47 Oct 31 14:42 ld64.lld -> ../@xpack-dev-tools/clang/.content/bin/ld64.lld
lrwxr-xr-x  1 ilg  staff  57 Oct 31 14:42 ld64.lld.darwinnew -> ../@xpack-dev-tools/clang/.content/bin/ld64.lld.darwinnew
lrwxr-xr-x  1 ilg  staff  42 Oct 31 14:42 lld -> ../@xpack-dev-tools/clang/.content/bin/lld
lrwxr-xr-x  1 ilg  staff  47 Oct 31 14:42 lld-link -> ../@xpack-dev-tools/clang/.content/bin/lld-link
lrwxr-xr-x  1 ilg  staff  43 Oct 31 14:42 lldb -> ../@xpack-dev-tools/clang/.content/bin/lldb
lrwxr-xr-x  1 ilg  staff  53 Oct 31 14:42 lldb-argdumper -> ../@xpack-dev-tools/clang/.content/bin/lldb-argdumper
lrwxr-xr-x  1 ilg  staff  49 Oct 31 14:42 lldb-instr -> ../@xpack-dev-tools/clang/.content/bin/lldb-instr
lrwxr-xr-x  1 ilg  staff  50 Oct 31 14:42 lldb-server -> ../@xpack-dev-tools/clang/.content/bin/lldb-server
lrwxr-xr-x  1 ilg  staff  50 Oct 31 14:42 lldb-vscode -> ../@xpack-dev-tools/clang/.content/bin/lldb-vscode
lrwxr-xr-x  1 ilg  staff  53 Oct 31 14:42 llvm-addr2line -> ../@xpack-dev-tools/clang/.content/bin/llvm-addr2line
lrwxr-xr-x  1 ilg  staff  46 Oct 31 14:42 llvm-ar -> ../@xpack-dev-tools/clang/.content/bin/llvm-ar
lrwxr-xr-x  1 ilg  staff  46 Oct 31 14:42 llvm-as -> ../@xpack-dev-tools/clang/.content/bin/llvm-as
lrwxr-xr-x  1 ilg  staff  57 Oct 31 14:42 llvm-bitcode-strip -> ../@xpack-dev-tools/clang/.content/bin/llvm-bitcode-strip
lrwxr-xr-x  1 ilg  staff  50 Oct 31 14:42 llvm-config -> ../@xpack-dev-tools/clang/.content/bin/llvm-config
lrwxr-xr-x  1 ilg  staff  47 Oct 31 14:42 llvm-cov -> ../@xpack-dev-tools/clang/.content/bin/llvm-cov
lrwxr-xr-x  1 ilg  staff  51 Oct 31 14:42 llvm-cxxdump -> ../@xpack-dev-tools/clang/.content/bin/llvm-cxxdump
lrwxr-xr-x  1 ilg  staff  51 Oct 31 14:42 llvm-cxxfilt -> ../@xpack-dev-tools/clang/.content/bin/llvm-cxxfilt
lrwxr-xr-x  1 ilg  staff  50 Oct 31 14:42 llvm-cxxmap -> ../@xpack-dev-tools/clang/.content/bin/llvm-cxxmap
lrwxr-xr-x  1 ilg  staff  48 Oct 31 14:42 llvm-diff -> ../@xpack-dev-tools/clang/.content/bin/llvm-diff
lrwxr-xr-x  1 ilg  staff  47 Oct 31 14:42 llvm-dis -> ../@xpack-dev-tools/clang/.content/bin/llvm-dis
lrwxr-xr-x  1 ilg  staff  51 Oct 31 14:42 llvm-dlltool -> ../@xpack-dev-tools/clang/.content/bin/llvm-dlltool
lrwxr-xr-x  1 ilg  staff  47 Oct 31 14:42 llvm-lib -> ../@xpack-dev-tools/clang/.content/bin/llvm-lib
lrwxr-xr-x  1 ilg  staff  58 Oct 31 14:42 llvm-libtool-darwin -> ../@xpack-dev-tools/clang/.content/bin/llvm-libtool-darwin
lrwxr-xr-x  1 ilg  staff  46 Oct 31 14:42 llvm-nm -> ../@xpack-dev-tools/clang/.content/bin/llvm-nm
lrwxr-xr-x  1 ilg  staff  51 Oct 31 14:42 llvm-objcopy -> ../@xpack-dev-tools/clang/.content/bin/llvm-objcopy
lrwxr-xr-x  1 ilg  staff  51 Oct 31 14:42 llvm-objdump -> ../@xpack-dev-tools/clang/.content/bin/llvm-objdump
lrwxr-xr-x  1 ilg  staff  52 Oct 31 14:42 llvm-profdata -> ../@xpack-dev-tools/clang/.content/bin/llvm-profdata
lrwxr-xr-x  1 ilg  staff  50 Oct 31 14:42 llvm-ranlib -> ../@xpack-dev-tools/clang/.content/bin/llvm-ranlib
lrwxr-xr-x  1 ilg  staff  46 Oct 31 14:42 llvm-rc -> ../@xpack-dev-tools/clang/.content/bin/llvm-rc
lrwxr-xr-x  1 ilg  staff  51 Oct 31 14:42 llvm-readelf -> ../@xpack-dev-tools/clang/.content/bin/llvm-readelf
lrwxr-xr-x  1 ilg  staff  51 Oct 31 14:42 llvm-readobj -> ../@xpack-dev-tools/clang/.content/bin/llvm-readobj
lrwxr-xr-x  1 ilg  staff  48 Oct 31 14:42 llvm-size -> ../@xpack-dev-tools/clang/.content/bin/llvm-size
lrwxr-xr-x  1 ilg  staff  51 Oct 31 14:42 llvm-strings -> ../@xpack-dev-tools/clang/.content/bin/llvm-strings
lrwxr-xr-x  1 ilg  staff  49 Oct 31 14:42 llvm-strip -> ../@xpack-dev-tools/clang/.content/bin/llvm-strip
lrwxr-xr-x  1 ilg  staff  54 Oct 31 14:42 llvm-symbolizer -> ../@xpack-dev-tools/clang/.content/bin/llvm-symbolizer
lrwxr-xr-x  1 ilg  staff  50 Oct 31 14:42 llvm-tblgen -> ../@xpack-dev-tools/clang/.content/bin/llvm-tblgen
lrwxr-xr-x  1 ilg  staff  57 Oct 31 14:42 set-xcode-analyzer -> ../@xpack-dev-tools/clang/.content/bin/set-xcode-analyzer
lrwxr-xr-x  1 ilg  staff  49 Oct 31 14:42 split-file -> ../@xpack-dev-tools/clang/.content/bin/split-file
lrwxr-xr-x  1 ilg  staff  46 Oct 31 14:42 wasm-ld -> ../@xpack-dev-tools/clang/.content/bin/wasm-ld

xpacks/@micro-os-plus:
total 0
lrwxr-xr-x  1 ilg  staff  75 Oct 31 14:42 architecture-synthetic-posix -> /Users/ilg/Library/xPacks/@micro-os-plus/architecture-synthetic-posix/4.0.2

xpacks/@xpack-dev-tools:
total 0
lrwxr-xr-x  1 ilg  staff  59 Oct 31 14:42 clang -> /Users/ilg/Library/xPacks/@xpack-dev-tools/clang/13.0.1-1.1
ilg at wksi native-cmake-clang13-debug % 
```

This project in particular has binary dependencies only to clang, but other projects can also have dependencies to cmake, ninja, etc, and all binaries are linked in the `.bin` folder.

With the proposed change, clang correctly idenifies the proper `include/c++/v1` folder from the final destination where the toolchain is installed.


https://github.com/llvm/llvm-project/pull/70817