[Wdocumentation] improve wording of a warning message

[Mordante]

Summary

Based on @davezarzycki remarks in D64696 improved the wording of the warning message.

(Note I don't have commit access)

[davezarzycki]

Works for me. Thanks!

[Mordante]

You're welcome @davezarzycki. Can one of you commit the patch?

[gribozavr]

I will commit on Monday.

[Mordante]

Thanks.

cfe/trunk/include/clang/Basic/DiagnosticCommentKinds.td

def warn_doc_deprecated_not_sync : Warning<
   InGroup<DocumentationDeprecatedSync>, DefaultIgnore;
 
 def note_add_deprecation_attr : Note<
   "add a deprecation attribute to the declaration to silence this warning">;
 
 // inline contents commands
 
 def warn_doc_inline_contents_no_argument : Warning<
-  "'%select{\\|@}0%1' command does not have an argument">,
+  "'%select{\\|@}0%1' command does not have a valid word argument">,
   InGroup<Documentation>, DefaultIgnore;
 
 // verbatim block commands
 
 def warn_verbatim_block_end_without_start : Warning<
   "'%select{\\|@}0%1' command does not terminate a verbatim text block">,
   InGroup<Documentation>, DefaultIgnore;
 

cfe/trunk/test/Sema/warn-documentation.cpp

struct test_attach38 {
   void test_attach39(T a, B b);
 };
 
 template <>
 template <typename B>
 void test_attach38<int>::test_attach39(int, B);
 
 // The inline comments expect a string after the command.
-// expected-warning@+1 {{'\a' command does not have an argument}}
+// expected-warning@+1 {{'\a' command does not have a valid word argument}}
 /// \a
 int test_inline_no_argument_a_bad(int);
 
 /// \a A
 int test_inline_no_argument_a_good(int);
 
-// expected-warning@+1 {{'@b' command does not have an argument}}
+// expected-warning@+1 {{'@b' command does not have a valid word argument}}
 /// @b
 int test_inline_no_argument_b_bad(int);
 
 /// @b A
 int test_inline_no_argument_b_good(int);
 
-// expected-warning@+1 {{'\c' command does not have an argument}}
+// expected-warning@+1 {{'\c' command does not have a valid word argument}}
 /// \c
 int test_inline_no_argument_c_bad(int);
 
 /// \c A
 int test_inline_no_argument_c_good(int);
 
-// expected-warning@+1 {{'\e' command does not have an argument}}
+// expected-warning@+1 {{'\e' command does not have a valid word argument}}
 /// \e
 int test_inline_no_argument_e_bad(int);
 
 /// \e A
 int test_inline_no_argument_e_good(int);
 
-// expected-warning@+1 {{'\em' command does not have an argument}}
+// expected-warning@+1 {{'\em' command does not have a valid word argument}}
 /// \em
 int test_inline_no_argument_em_bad(int);
 
 /// \em A
 int test_inline_no_argument_em_good(int);
 
-// expected-warning@+1 {{'\p' command does not have an argument}}
+// expected-warning@+1 {{'\p' command does not have a valid word argument}}
 /// \p
 int test_inline_no_argument_p_bad(int);
 
 /// \p A
 int test_inline_no_argument_p_good(int);
 
 // PR13411, reduced.  We used to crash on this.
 /**