util/StringStrip: add more "nonnull" attributes

src/util/StringStrip.cxx

 /*
- * Copyright (C) 2009-2017 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright 2009-2018 Max Kellermann <max.kellermann@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

src/util/StringStrip.hxx

 /*
- * Copyright (C) 2009-2017 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright 2009-2018 Max Kellermann <max.kellermann@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -38,32 +38,32 @@
  * Returns a pointer to the first non-whitespace character in the
  * string, or to the end of the string.
  */
-gcc_pure
+gcc_pure gcc_returns_nonnull gcc_nonnull_all
 const char *
 StripLeft(const char *p) noexcept;
 
-gcc_pure
+gcc_pure gcc_returns_nonnull gcc_nonnull_all
 static inline char *
 StripLeft(char *p) noexcept
 {
 	return const_cast<char *>(StripLeft((const char *)p));
 }
 
-gcc_pure
+gcc_pure gcc_returns_nonnull gcc_nonnull_all
 const char *
 StripLeft(const char *p, const char *end) noexcept;
 
 /**
  * Determine the string's end as if it was stripped on the right side.
  */
-gcc_pure
+gcc_pure gcc_returns_nonnull gcc_nonnull_all
 const char *
 StripRight(const char *p, const char *end) noexcept;
 
 /**
  * Determine the string's end as if it was stripped on the right side.
  */
-gcc_pure
+gcc_pure gcc_returns_nonnull gcc_nonnull_all
 static inline char *
 StripRight(char *p, char *end) noexcept
 {
@@ -75,13 +75,14 @@ StripRight(char *p, char *end) noexcept
  * Determine the string's length as if it was stripped on the right
  * side.
  */
-gcc_pure
+gcc_pure gcc_nonnull_all
 size_t
 StripRight(const char *p, size_t length) noexcept;
 
 /**
  * Strip trailing whitespace by null-terminating the string.
  */
+gcc_nonnull_all
 void
 StripRight(char *p) noexcept;
 
@@ -89,6 +90,7 @@ StripRight(char *p) noexcept;
  * Skip whitespace at the beginning and terminate the string after the
  * last non-whitespace character.
  */
+gcc_returns_nonnull gcc_nonnull_all
 char *
 Strip(char *p) noexcept;