clang/apple-clang correct c/c++ standard flags (#35062)

lib/spack/spack/compilers/apple_clang.py

@@ -36,36 +36,89 @@ def extract_version_from_output(cls, output):
             ver = match.group(match.lastindex)
         return ver
 
+    # C++ flags based on CMake Modules/Compiler/AppleClang-CXX.cmake
+
     @property
     def cxx11_flag(self):
-        # Adapted from CMake's AppleClang-CXX rules
         # Spack's AppleClang detection only valid from Xcode >= 4.6
-        if self.real_version < spack.version.ver("4.0.0"):
+        if self.real_version < spack.version.ver("4.0"):
             raise spack.compiler.UnsupportedCompilerFlag(
-                self, "the C++11 standard", "cxx11_flag", "Xcode < 4.0.0"
+                self, "the C++11 standard", "cxx11_flag", "Xcode < 4.0"
             )
         return "-std=c++11"
 
     @property
     def cxx14_flag(self):
-        # Adapted from CMake's rules for AppleClang
+        if self.real_version < spack.version.ver("5.1"):
-        if self.real_version < spack.version.ver("5.1.0"):
             raise spack.compiler.UnsupportedCompilerFlag(
-                self, "the C++14 standard", "cxx14_flag", "Xcode < 5.1.0"
+                self, "the C++14 standard", "cxx14_flag", "Xcode < 5.1"
             )
-        elif self.real_version < spack.version.ver("6.1.0"):
+        elif self.real_version < spack.version.ver("6.1"):
             return "-std=c++1y"
 
         return "-std=c++14"
 
     @property
     def cxx17_flag(self):
-        # Adapted from CMake's rules for AppleClang
+        if self.real_version < spack.version.ver("6.1"):
-        if self.real_version < spack.version.ver("6.1.0"):
             raise spack.compiler.UnsupportedCompilerFlag(
-                self, "the C++17 standard", "cxx17_flag", "Xcode < 6.1.0"
+                self, "the C++17 standard", "cxx17_flag", "Xcode < 6.1"
             )
-        return "-std=c++1z"
+        elif self.real_version < spack.version.ver("10.0"):
+            return "-std=c++1z"
+        return "-std=c++17"
+
+    @property
+    def cxx20_flag(self):
+        if self.real_version < spack.version.ver("10.0"):
+            raise spack.compiler.UnsupportedCompilerFlag(
+                self, "the C++20 standard", "cxx20_flag", "Xcode < 10.0"
+            )
+        elif self.real_version < spack.version.ver("13.0"):
+            return "-std=c++2a"
+        return "-std=c++20"
+
+    @property
+    def cxx23_flag(self):
+        if self.real_version < spack.version.ver("13.0"):
+            raise spack.compiler.UnsupportedCompilerFlag(
+                self, "the C++23 standard", "cxx23_flag", "Xcode < 13.0"
+            )
+        return "-std=c++2b"
+
+    # C flags based on CMake Modules/Compiler/AppleClang-C.cmake
+
+    @property
+    def c99_flag(self):
+        if self.real_version < spack.version.ver("4.0"):
+            raise spack.compiler.UnsupportedCompilerFlag(
+                self, "the C99 standard", "c99_flag", "< 4.0"
+            )
+        return "-std=c99"
+
+    @property
+    def c11_flag(self):
+        if self.real_version < spack.version.ver("4.0"):
+            raise spack.compiler.UnsupportedCompilerFlag(
+                self, "the C11 standard", "c11_flag", "< 4.0"
+            )
+        return "-std=c11"
+
+    @property
+    def c17_flag(self):
+        if self.real_version < spack.version.ver("11.0"):
+            raise spack.compiler.UnsupportedCompilerFlag(
+                self, "the C17 standard", "c17_flag", "< 11.0"
+            )
+        return "-std=c17"
+
+    @property
+    def c23_flag(self):
+        if self.real_version < spack.version.ver("11.0.3"):
+            raise spack.compiler.UnsupportedCompilerFlag(
+                self, "the C23 standard", "c23_flag", "< 11.0.3"
+            )
+        return "-std=c2x"
 
     def setup_custom_environment(self, pkg, env):
         """Set the DEVELOPER_DIR environment for the Xcode toolchain.

lib/spack/spack/compilers/clang.py

@@ -128,10 +128,23 @@ def c99_flag(self):
 
     @property
     def c11_flag(self):
-        if self.real_version < ver("6.1.0"):
+        if self.real_version < ver("3.0"):
-            raise UnsupportedCompilerFlag(self, "the C11 standard", "c11_flag", "< 6.1.0")
+            raise UnsupportedCompilerFlag(self, "the C11 standard", "c11_flag", "< 3.0")
-        else:
+        if self.real_version < ver("3.1"):
-            return "-std=c11"
+            return "-std=c1x"
+        return "-std=c11"
+
+    @property
+    def c17_flag(self):
+        if self.real_version < ver("6.0"):
+            raise UnsupportedCompilerFlag(self, "the C17 standard", "c17_flag", "< 6.0")
+        return "-std=c17"
+
+    @property
+    def c23_flag(self):
+        if self.real_version < ver("9.0"):
+            raise UnsupportedCompilerFlag(self, "the C23 standard", "c23_flag", "< 9.0")
+        return "-std=c2x"
 
     @property
     def cc_pic_flag(self):

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

@@ -389,7 +389,7 @@ def test_apple_clang_flags():
     unsupported_flag_test("cxx17_flag", "apple-clang@6.0.0")
     supported_flag_test("cxx17_flag", "-std=c++1z", "apple-clang@6.1.0")
     supported_flag_test("c99_flag", "-std=c99", "apple-clang@6.1.0")
-    unsupported_flag_test("c11_flag", "apple-clang@6.0.0")
+    unsupported_flag_test("c11_flag", "apple-clang@3.0.0")
     supported_flag_test("c11_flag", "-std=c11", "apple-clang@6.1.0")
     supported_flag_test("cc_pic_flag", "-fPIC", "apple-clang@2.0.0")
     supported_flag_test("cxx_pic_flag", "-fPIC", "apple-clang@2.0.0")
@@ -409,7 +409,7 @@ def test_clang_flags():
     supported_flag_test("cxx17_flag", "-std=c++1z", "clang@3.5")
     supported_flag_test("cxx17_flag", "-std=c++17", "clang@5.0")
     supported_flag_test("c99_flag", "-std=c99", "clang@3.3")
-    unsupported_flag_test("c11_flag", "clang@6.0.0")
+    unsupported_flag_test("c11_flag", "clang@2.0")
     supported_flag_test("c11_flag", "-std=c11", "clang@6.1.0")
     supported_flag_test("cc_pic_flag", "-fPIC", "clang@3.3")
     supported_flag_test("cxx_pic_flag", "-fPIC", "clang@3.3")