src/base/compiler.hh

   1 /*
   2  * Copyright (c) 2006 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Ali Saidi
  29  */
  30
  31 #ifndef __BASE_COMPILER_HH__
  32 #define __BASE_COMPILER_HH__
  33
  34 #include "config/have_static_assert.hh"
  35
  36 //http://msdn2.microsoft.com/en-us/library/ms937669.aspx
  37 //http://msdn2.microsoft.com/en-us/library/aa448724.aspx
  38 //http://docs.sun.com/source/819-3688/sun.specific.html#marker-998278
  39 //http://gcc.gnu.org/onlinedocs/gcc-3.3.1/gcc/Function-Attributes.html#Function%20Attributes
  40
  41 #if defined(__GNUC__)
  42 #define M5_ATTR_NORETURN  __attribute__((noreturn))
  43 #define M5_PRAGMA_NORETURN(x)
  44 #define M5_DUMMY_RETURN
  45 #define M5_VAR_USED __attribute__((unused))
  46 #define M5_ATTR_PACKED __attribute__ ((__packed__))
  47 #define M5_NO_INLINE __attribute__ ((__noinline__))
  48 #elif defined(__SUNPRO_CC)
  49 // this doesn't do anything with sun cc, but why not
  50 #define M5_ATTR_NORETURN  __sun_attr__((__noreturn__))
  51 #define M5_DUMMY_RETURN return (0);
  52 #define DO_PRAGMA(x) _Pragma(#x)
  53 #define M5_VAR_USED
  54 #define M5_PRAGMA_NORETURN(x) DO_PRAGMA(does_not_return(x))
  55 #define M5_ATTR_PACKED __attribute__ ((__packed__))
  56 #define M5_NO_INLINE __attribute__ ((__noinline__))
  57 #else
  58 #error "Need to define compiler options in base/compiler.hh"
  59 #endif
  60
  61 /*
  62  * Define a compatibility macro that emulates the behavior of
  63  * static_assert using template magic if the compiler doesn't have
  64  * native support.
  65  */
  66 #if !HAVE_STATIC_ASSERT
  67
  68 template<bool>
  69 struct static_assert_failure;
  70
  71 template<>
  72 struct static_assert_failure<false> {};
  73
  74 /* The following macro causes the compiler to evaluate the size of the
  75  * static_assert_failure struct. The templates are designed so that
  76  * only static_assert_failure<false> evaluates to a proper size, while
  77  * static_assert_failure<true> generates a compile time error.
  78  */
  79 #define static_assert(expr, msg)                                        \
  80     namespace ns_static_assert {                                        \
  81         enum {                                                          \
  82             static_assert_ ## __LINE__ =                                \
  83                 sizeof(static_assert_failure<!(expr)>)                  \
  84         };                                                              \
  85     }
  86
  87 #endif
  88
  89 #endif // __BASE_COMPILER_HH__