The `clang-scan-deps` CLI tool invokes the compiler with `-print-resource-dir` in case the `-resource-dir` argument is missing from the compilation command line. This is to enable running the tool on compilation databases that use compiler from a different toolchain than `clang-scan-deps` itself. While this doesn't make sense when scanning modular builds (due to the `-cc1` arguments the tool generates), the tool can can be used to efficiently scan for file dependencies of non-modular builds too.
This patch stops deducing the resource directory by invoking the compiler by default. This mode can still be enabled by invoking `clang-scan-deps` with `--resource-dir-recipe invoke-compiler`. The new default is `--resource-dir-recipe modify-compiler-path` which relies on the resource directory deduction taking place in `Driver::Driver` which is based on the compiler path. This makes the default more aligned with the intended usage of the tool while still allowing it to serve other use-cases.
Note that this functionality was also influenced by D108979, where the dependency scanner stopped going through `ClangTool::run`. The function tried to deduce the resource directory based on the current executable path, which might not be what the users expect when invoked from within a shared library.
Depends on D108979.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D108366
b8b14b682c