/* Compile-time assert-like macros.
- Copyright (C) 2005-2006, 2009-2011 Free Software Foundation, Inc.
+ Copyright (C) 2005-2006, 2009-2013 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
# define _GL_VERIFY_H
-/* Define _GL_HAVE__STATIC_ASSERT to 1 if _Static_assert works as per the
- C1X draft N1548 section 6.7.10. This is supported by GCC 4.6.0 and
- later, in C mode, and its use here generates easier-to-read diagnostics
- when verify (R) fails.
+/* Define _GL_HAVE__STATIC_ASSERT to 1 if _Static_assert works as per C11.
+ This is supported by GCC 4.6.0 and later, in C mode, and its use
+ here generates easier-to-read diagnostics when verify (R) fails.
- Define _GL_HAVE_STATIC_ASSERT to 1 if static_assert works as per the
- C++0X draft N3242 section 7.(4).
+ Define _GL_HAVE_STATIC_ASSERT to 1 if static_assert works as per C++11.
This will likely be supported by future GCC versions, in C++ mode.
Use this only with GCC. If we were willing to slow 'configure'
down we could also use it with other compilers, but since this
affects only the quality of diagnostics, why bother? */
-# if (4 < __GNUC__ || (__GNUC__ == 4 && 6 <= __GNUC_MINOR__)) && !defined __cplusplus
+# if (4 < __GNUC__ + (6 <= __GNUC_MINOR__) \
+ && (201112L <= __STDC_VERSION__ || !defined __STRICT_ANSI__) \
+ && !defined __cplusplus)
# define _GL_HAVE__STATIC_ASSERT 1
# endif
/* The condition (99 < __GNUC__) is temporary, until we know about the
extern int (*dummy (void)) [sizeof (struct {...})];
* GCC warns about duplicate declarations of the dummy function if
- -Wredundant_decls is used. GCC 4.3 and later have a builtin
+ -Wredundant-decls is used. GCC 4.3 and later have a builtin
__COUNTER__ macro that can let us generate unique identifiers for
each dummy function, to suppress this warning.
which do not support _Static_assert, also do not warn about the
last declaration mentioned above.
+ * GCC warns if -Wnested-externs is enabled and verify() is used
+ within a function body; but inside a function, you can always
+ arrange to use verify_expr() instead.
+
* In C++, any struct definition inside sizeof is invalid.
Use a template type to work around the problem. */
(!!sizeof (_GL_VERIFY_TYPE (R, DIAGNOSTIC)))
# ifdef __cplusplus
+# if !GNULIB_defined_struct__gl_verify_type
template <int w>
struct _gl_verify_type {
unsigned int _gl_verify_error_if_negative: w;
};
+# define GNULIB_defined_struct__gl_verify_type 1
+# endif
# define _GL_VERIFY_TYPE(R, DIAGNOSTIC) \
_gl_verify_type<(R) ? 1 : -1>
# elif defined _GL_HAVE__STATIC_ASSERT
trailing ';'. If R is false, fail at compile-time, preferably
with a diagnostic that includes the string-literal DIAGNOSTIC.
- Unfortunately, unlike C1X, this implementation must appear as an
+ Unfortunately, unlike C11, this implementation must appear as an
ordinary declaration, and cannot appear inside struct { ... }. */
# ifdef _GL_HAVE__STATIC_ASSERT
# define _Static_assert(R, DIAGNOSTIC) _GL_VERIFY (R, DIAGNOSTIC)
# endif
# if !defined _GL_HAVE_STATIC_ASSERT && !defined static_assert
-# define static_assert _Static_assert /* Draft C1X requires this #define. */
+# define static_assert _Static_assert /* C11 requires this #define. */
# endif
-# else
+# endif
+
+/* @assert.h omit start@ */
/* Each of these macros verifies that its argument R is nonzero. To
be portable, R should be an integer constant expression. Unlike
contexts, e.g., the top level. */
/* Verify requirement R at compile-time, as an integer constant expression.
- Return 1. */
+ Return 1. This is equivalent to verify_expr (R, 1).
-# define verify_true(R) _GL_VERIFY_TRUE (R, "verify_true (" #R ")")
+ verify_true is obsolescent; please use verify_expr instead. */
+
+# define verify_true(R) _GL_VERIFY_TRUE (R, "verify_true (" #R ")")
+
+/* Verify requirement R at compile-time. Return the value of the
+ expression E. */
+
+# define verify_expr(R, E) \
+ (_GL_VERIFY_TRUE (R, "verify_expr (" #R ", " #E ")") ? (E) : (E))
/* Verify requirement R at compile-time, as a declaration without a
trailing ';'. */
-# define verify(R) _GL_VERIFY (R, "verify (" #R ")")
+# define verify(R) _GL_VERIFY (R, "verify (" #R ")")
-# endif
+/* @assert.h omit end@ */
#endif