Specify GCC prefix in LLVM-based compilers (#33146)

* spack.compiler.Compiler: introduce prefix property

We currently don't really have something that gives the GCC install
path, which is used by many LLVM-based compilers (llvm, llvm-amdgpu,
nvhpc, ...) to fix the GCC toolchain once and for all.

This `prefix` property is dynamic in the sense that it queries the
compiler itself. This is necessary because it's not easy to deduce the
install path from the `cc` property (might be a symlink, might be a
filename like `gcc` which works by having the compiler load a module
that sets the PATH variable, might be a generic compiler wrapper based
on environment variables like on cray...).

With this property introduced, we can clean up some recipes that have
the logic repeated for GCC.

* intel-oneapi-compilers: set --gcc-sysroot to %gcc prefix

1 files changed, 1 insertions, 11 deletions

diff --git a/var/spack/repos/builtin/packages/llvm/package.py b/var/spack/repos/builtin/packages/llvm/package.py
index 5751629f5f..d7958bd6f8 100644
--- a/var/spack/repos/builtin/packages/llvm/package.py
+++ b/var/spack/repos/builtin/packages/llvm/package.py
@@ -721,17 +721,7 @@ class Llvm(CMakePackage, CudaPackage):
         cmake_args.append(from_variant("LIBOMP_TSAN_SUPPORT", "omp_tsan"))
 
         if self.compiler.name == "gcc":
-            compiler = Executable(self.compiler.cc)
-            gcc_output = compiler("-print-search-dirs", output=str, error=str)
-
-            for line in gcc_output.splitlines():
-                if line.startswith("install:"):
-                    # Get path and strip any whitespace
-                    # (causes oddity with ancestor)
-                    gcc_prefix = line.split(":")[1].strip()
-                    gcc_prefix = ancestor(gcc_prefix, 4)
-                    break
-            cmake_args.append(define("GCC_INSTALL_PREFIX", gcc_prefix))
+            cmake_args.append(define("GCC_INSTALL_PREFIX", self.compiler.prefix))
 
         if self.spec.satisfies("~code_signing platform=darwin"):
             cmake_args.append(define("LLDB_USE_SYSTEM_DEBUGSERVER", True))