Fix a bug with automatic tag detection (#45696)

Extracted from #45638

When adding the "detectable" tag to a package class that has the
"tag" attribute inherited from a base class, we need to copy it to
avoid modifying the base class.

3 files changed, 40 insertions, 2 deletions

diff --git a/var/spack/repos/builtin.mock/packages/gcc/package.py b/var/spack/repos/builtin.mock/packages/gcc/package.py
index 31f7c95b53..05518419dd 100644
--- a/var/spack/repos/builtin.mock/packages/gcc/package.py
+++ b/var/spack/repos/builtin.mock/packages/gcc/package.py
@@ -6,7 +6,7 @@
 from spack.package import *
 
 
-class Gcc(Package):
+class Gcc(CompilerPackage, Package):
     """Simple compiler package."""
 
     homepage = "http://www.example.com"
@@ -18,6 +18,10 @@ class Gcc(Package):
 
     depends_on("conflict", when="@3.0")
 
+    c_names = ["gcc"]
+    cxx_names = ["g++"]
+    fortran_names = ["gfortran"]
+
     def install(self, spec, prefix):
         # Create the minimal compiler that will fool `spack compiler find`
         mkdirp(prefix.bin)
diff --git a/var/spack/repos/builtin.mock/packages/intel-oneapi-compilers/package.py b/var/spack/repos/builtin.mock/packages/intel-oneapi-compilers/package.py
index f7c7dd67e5..78fdbe056c 100644
--- a/var/spack/repos/builtin.mock/packages/intel-oneapi-compilers/package.py
+++ b/var/spack/repos/builtin.mock/packages/intel-oneapi-compilers/package.py
@@ -8,7 +8,7 @@ import sys
 from spack.package import *
 
 
-class IntelOneapiCompilers(Package):
+class IntelOneapiCompilers(Package, CompilerPackage):
     """Simple compiler package."""
 
     homepage = "http://www.example.com"
@@ -18,6 +18,10 @@ class IntelOneapiCompilers(Package):
     version("2.0", md5="abcdef0123456789abcdef0123456789")
     version("3.0", md5="def0123456789abcdef0123456789abc")
 
+    c_names = ["icx"]
+    cxx_names = ["icpx"]
+    fortran_names = ["ifx"]
+
     @property
     def compiler_search_prefix(self):
         return self.prefix.foo.bar.baz.bin
diff --git a/var/spack/repos/builtin.mock/packages/llvm/package.py b/var/spack/repos/builtin.mock/packages/llvm/package.py
new file mode 100644
index 0000000000..135ae5ebfa
--- /dev/null
+++ b/var/spack/repos/builtin.mock/packages/llvm/package.py
@@ -0,0 +1,30 @@
+# Copyright 2013-2024 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack.package import *
+
+
+class Llvm(Package, CompilerPackage):
+    """Simple compiler package."""
+
+    homepage = "http://www.example.com"
+    url = "http://www.example.com/gcc-1.0.tar.gz"
+
+    version("18.1.8", md5="0123456789abcdef0123456789abcdef")
+
+    variant(
+        "clang", default=True, description="Build the LLVM C/C++/Objective-C compiler frontend"
+    )
+
+    c_names = ["clang"]
+    cxx_names = ["clang++"]
+    fortran_names = ["flang"]
+
+    def install(self, spec, prefix):
+        # Create the minimal compiler that will fool `spack compiler find`
+        mkdirp(prefix.bin)
+        with open(prefix.bin.gcc, "w") as f:
+            f.write('#!/bin/bash\necho "%s"' % str(spec.version))
+        set_executable(prefix.bin.gcc)