aocc: add support for v3.0 compilers (#22219)

A mitigation of a known issue that affects v3.0 is added, see
https://developer.amd.com/wp-content/resources/AOCC-3.0-Install-Guide.pdf

lib/spack/spack/compilers/aocc.py

@@ -9,6 +9,7 @@
 import llnl.util.lang
 
 from spack.compiler import Compiler
+from spack.version import ver
 
 
 class Aocc(Compiler):
@@ -118,3 +119,22 @@ def f77_version(cls, f77):
     @property
     def stdcxx_libs(self):
         return ('-lstdc++', )
+
+    @property
+    def cflags(self):
+        return self._handle_default_flag_addtions()
+
+    @property
+    def cxxflags(self):
+        return self._handle_default_flag_addtions()
+
+    @property
+    def fflags(self):
+        return self._handle_default_flag_addtions()
+
+    def _handle_default_flag_addtions(self):
+        # This is a known issue for AOCC 3.0 see:
+        # https://developer.amd.com/wp-content/resources/AOCC-3.0-Install-Guide.pdf
+        if self.real_version == ver('3.0.0'):
+            return ("-Wno-unused-command-line-argument "
+                    "-mllvm -eliminate-similar-expr=false")

lib/spack/spack/test/compilers/basics.py

@@ -466,6 +466,10 @@ def test_aocc_flags():
     supported_flag_test("f77_pic_flag", "-fPIC", "aocc@2.2.0")
     supported_flag_test("fc_pic_flag", "-fPIC", "aocc@2.2.0")
     supported_flag_test("version_argument", "--version", "aocc@2.2.0")
+    flg = "-Wno-unused-command-line-argument -mllvm -eliminate-similar-expr=false"
+    supported_flag_test("cflags", flg, "aocc@3.0.0")
+    supported_flag_test("cxxflags", flg, "aocc@3.0.0")
+    supported_flag_test("fflags", flg, "aocc@3.0.0")
 
 
 def test_fj_flags():

lib/spack/spack/test/compilers/detection.py

@@ -321,6 +321,11 @@ def _module(cmd, *args):
 
 @pytest.mark.parametrize('version_str,expected_version', [
     # This applies to C,C++ and FORTRAN compiler
+    ('AMD clang version 12.0.0 (CLANG: AOCC_3.0.0-Build#78 2020_12_10)'
+     '(based on LLVM Mirror.Version.12.0.0)\n'
+     'Target: x86_64-unknown-linux-gnu\n'
+     'Thread model: posix\n', '3.0.0'
+     ),
     ('AMD clang version 11.0.0 (CLANG: AOCC_2.3.0-Build#85 2020_11_10)'
      '(based on LLVM Mirror.Version.11.0.0)\n'
      'Target: x86_64-unknown-linux-gnu\n'