add C standard flags to compiler classes (#11618)

* add c99_flag, c11_flag to compiler class

* implement c99_flag, c11_flag for gcc

* implement c99_flag, c11_flag for arm

* implement c99_flag for cce

* implement c99_flag, c11_flag for clang

* implement c99_flag, c11_flag for intel

* implement c99_flag, c11_flag for xl

lib/spack/spack/compiler.py

@@ -195,6 +195,24 @@ def cxx17_flag(self):
                                       "the C++17 standard",
                                       "cxx17_flag")
 
+    # This property should be overridden in the compiler subclass if
+    # C99 is supported by that compiler
+    @property
+    def c99_flag(self):
+        # If it is not overridden, assume it is not supported and warn the user
+        raise UnsupportedCompilerFlag(self,
+                                      "the C99 standard",
+                                      "c99_flag")
+
+    # This property should be overridden in the compiler subclass if
+    # C11 is supported by that compiler
+    @property
+    def c11_flag(self):
+        # If it is not overridden, assume it is not supported and warn the user
+        raise UnsupportedCompilerFlag(self,
+                                      "the C11 standard",
+                                      "c11_flag")
+
     #
     # Compiler classes have methods for querying the version of
     # specific compiler executables.  This is used when discovering compilers.

lib/spack/spack/compilers/arm.py

@@ -53,6 +53,14 @@ def cxx14_flag(self):
     def cxx17_flag(self):
         return "-std=c++1z"
 
+    @property
+    def c99_flag(self):
+        return "-std=c99"
+
+    @property
+    def c11_flag(self):
+        return "-std=c11"
+
     @property
     def pic_flag(self):
         return "-fPIC"

lib/spack/spack/compilers/cce.py

@@ -42,6 +42,10 @@ def openmp_flag(self):
     def cxx11_flag(self):
         return "-h std=c++11"
 
+    @property
+    def c99_flag(self):
+        return "-h c99"
+
     @property
     def pic_flag(self):
         return "-h PIC"

lib/spack/spack/compilers/clang.py

@@ -157,6 +157,20 @@ def cxx17_flag(self):
             else:
                 return "-std=c++17"
 
+    @property
+    def c99_flag(self):
+        return '-std=c99'
+
+    @property
+    def c11_flag(self):
+        if self.version < ver('6.1.0'):
+            raise UnsupportedCompilerFlag(self,
+                                          "the C11 standard",
+                                          "c11_flag",
+                                          "< 3.3")
+        else:
+            return "-std=c11"
+
     @property
     def pic_flag(self):
         return "-fPIC"

lib/spack/spack/compilers/gcc.py

@@ -87,6 +87,24 @@ def cxx17_flag(self):
         else:
             return "-std=c++17"
 
+    @property
+    def c99_flag(self):
+        if self.version < ver('4.5'):
+            raise UnsupportedCompilerFlag(self,
+                                          "the C99 standard",
+                                          "c99_flag",
+                                          "< 4.5")
+        return "-std=c99"
+
+    @property
+    def c11_flag(self):
+        if self.version < ver('4.7'):
+            raise UnsupportedCompilerFlag(self,
+                                          "the C11 standard",
+                                          "c11_flag",
+                                          "< 4.7")
+        return "-std=c11"
+
     @property
     def pic_flag(self):
         return "-fPIC"

lib/spack/spack/compilers/intel.py

@@ -65,6 +65,26 @@ def cxx14_flag(self):
         else:
             return "-std=c++14"
 
+    @property
+    def c99_flag(self):
+        if self.version < ver('12'):
+            raise UnsupportedCompilerFlag(self,
+                                          "the C99 standard",
+                                          "c99_flag",
+                                          "< 12")
+        else:
+            return "-std=c99"
+
+    @property
+    def c11_flag(self):
+        if self.version < ver('16'):
+            raise UnsupportedCompilerFlag(self,
+                                          "the C11 standard",
+                                          "c11_flag",
+                                          "< 16")
+        else:
+            return "-std=c1x"
+
     @property
     def pic_flag(self):
         return "-fPIC"

lib/spack/spack/compilers/xl.py

@@ -43,6 +43,14 @@ def cxx11_flag(self):
         else:
             return "-qlanglvl=extended0x"
 
+    @property
+    def c99_flag(self):
+        return '-std=c99'
+
+    @property
+    def c11_flag(self):
+        return '-std=c11'
+
     @property
     def pic_flag(self):
         return "-qpic"