Comments on nagfor options setup.

mesonbuild/compilers/fortran.py

@@ -494,6 +494,7 @@ class NAGFortranCompiler(FortranCompiler):
                                  is_cross, info, exe_wrapper, linker=linker,
                                  full_version=full_version)
         self.id = 'nagfor'
+        # Warnings are on by default; -w disables (by category):
         self.warn_args = {
             '0': ['-w=all'],
             '1': [],

mesonbuild/linkers/linkers.py

@@ -1047,7 +1047,14 @@ class QualcommLLVMDynamicLinker(LLVMDynamicLinker):
 
 class NAGDynamicLinker(PosixDynamicLinkerMixin, DynamicLinker):
 
-    """NAG Fortran linker, ld via gcc indirection."""
+    """NAG Fortran linker, ld via gcc indirection.
+
+    Using nagfor -Wl,foo passes option foo to a backend gcc invocation.
+    (This linking gathers the correct objects needed from the nagfor runtime
+    system.)
+    To pass gcc -Wl,foo options (i.e., to ld) one must apply indirection
+    again: nagfor -Wl,-Wl,,foo
+    """
 
     id = 'nag'