clint: Allow omitting include guards in .c.h file and func_attr.h file

src/clint.py

@@ -182,6 +182,7 @@ _ERROR_CATEGORIES = [
     'build/include_order',
     'build/printf_format',
     'build/storage_class',
+    'build/useless_fattr',
     'readability/alt_tokens',
     'readability/bool',
     'readability/braces',
@@ -1224,6 +1225,10 @@ def CheckForHeaderGuard(filename, lines, error):
       lines: An array of strings, each representing a line of the file.
       error: The function to call with any errors found.
     """
+    if filename.endswith('.c.h') or FileInfo(filename).RelativePath() in set((
+        'func_attr.h',
+    )):
+        return
 
     cppvar = GetHeaderGuardCPPVariable(filename)
 

src/nvim/eval/typval_encode.c.h

@@ -233,10 +233,6 @@
 ///
 /// This name will only be used by one of the above macros which are defined by
 /// the caller. Functions defined here do not use first argument directly.
-#ifndef NVIM_EVAL_TYPVAL_ENCODE_C_H
-#define NVIM_EVAL_TYPVAL_ENCODE_C_H
-#undef NVIM_EVAL_TYPVAL_ENCODE_C_H
-
 #include <stddef.h>
 #include <inttypes.h>
 #include <assert.h>
@@ -816,4 +812,3 @@ encode_vim_to__error_ret:
   // Prevent “unused label” warnings.
   goto typval_encode_stop_converting_one_item;
 }
-#endif  // NVIM_EVAL_TYPVAL_ENCODE_C_H

src/nvim/func_attr.h

@@ -41,10 +41,6 @@
 // $ gcc -E -dM - </dev/null
 // $ echo | clang -dM -E -
 
-#ifndef NVIM_FUNC_ATTR_H
-#define NVIM_FUNC_ATTR_H
-#undef NVIM_FUNC_ATTR_H
-
 #ifdef FUNC_ATTR_MALLOC
 # undef FUNC_ATTR_MALLOC
 #endif
@@ -213,4 +209,3 @@
 # define FUNC_ATTR_NONNULL_ARG(...)
 # define FUNC_ATTR_NONNULL_RET
 #endif
-#endif  // NVIM_FUNC_ATTR_H