mbed_toolchain.h

00001 
00002 /** \addtogroup platform */
00003 /** @{*/
00004 /* mbed Microcontroller Library
00005  * Copyright (c) 2006-2013 ARM Limited
00006  *
00007  * Licensed under the Apache License, Version 2.0 (the "License");
00008  * you may not use this file except in compliance with the License.
00009  * You may obtain a copy of the License at
00010  *
00011  *     http://www.apache.org/licenses/LICENSE-2.0
00012  *
00013  * Unless required by applicable law or agreed to in writing, software
00014  * distributed under the License is distributed on an "AS IS" BASIS,
00015  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00016  * See the License for the specific language governing permissions and
00017  * limitations under the License.
00018  */
00019 #ifndef MBED_TOOLCHAIN_H
00020 #define MBED_TOOLCHAIN_H
00021 
00022 #include "mbed_preprocessor.h"
00023 
00024 
00025 // Warning for unsupported compilers
00026 #if !defined(__GNUC__)   /* GCC        */ \
00027  && !defined(__CC_ARM)   /* ARMCC      */ \
00028  && !defined(__clang__)  /* LLVM/Clang */ \
00029  && !defined(__ICCARM__) /* IAR        */
00030 #warning "This compiler is not yet supported."
00031 #endif
00032 
00033 
00034 // Attributes
00035 
00036 /** MBED_PACKED
00037  *  Pack a structure, preventing any padding from being added between fields.
00038  *
00039  *  @code
00040  *  #include "mbed_toolchain.h"
00041  *
00042  *  MBED_PACKED(struct) foo {
00043  *      char x;
00044  *      int y;
00045  *  };
00046  *  @endcode
00047  */
00048 #ifndef MBED_PACKED
00049 #if defined(__ICCARM__)
00050 #define MBED_PACKED(struct) __packed struct
00051 #else
00052 #define MBED_PACKED(struct) struct __attribute__((packed))
00053 #endif
00054 #endif
00055 
00056 /** MBED_ALIGN(N)
00057  *  Declare a variable to be aligned on an N-byte boundary.
00058  *
00059  *  @note
00060  *  IAR does not support alignment greater than word size on the stack
00061  *  
00062  *  @code
00063  *  #include "mbed_toolchain.h"
00064  *
00065  *  MBED_ALIGN(16) char a;
00066  *  @endcode
00067  */
00068 #ifndef MBED_ALIGN
00069 #if defined(__ICCARM__)
00070 #define MBED_ALIGN(N) _Pragma(MBED_STRINGIFY(data_alignment=N))
00071 #else
00072 #define MBED_ALIGN(N) __attribute__((aligned(N)))
00073 #endif
00074 #endif
00075 
00076 /** MBED_UNUSED
00077  *  Declare a function argument to be unused, suppressing compiler warnings
00078  *
00079  *  @code
00080  *  #include "mbed_toolchain.h"
00081  *
00082  *  void foo(MBED_UNUSED int arg) {
00083  *
00084  *  }
00085  *  @endcode
00086  */
00087 #ifndef MBED_UNUSED
00088 #if defined(__GNUC__) || defined(__clang__) || defined(__CC_ARM)
00089 #define MBED_UNUSED __attribute__((__unused__))
00090 #else
00091 #define MBED_UNUSED
00092 #endif
00093 #endif
00094 
00095 /** MBED_WEAK
00096  *  Mark a function as being weak.
00097  *  
00098  *  @note
00099  *  weak functions are not friendly to making code re-usable, as they can only
00100  *  be overridden once (and if they are multiply overridden the linker will emit
00101  *  no warning). You should not normally use weak symbols as part of the API to
00102  *  re-usable modules.
00103  *  
00104  *  @code
00105  *  #include "mbed_toolchain.h"
00106  *  
00107  *  MBED_WEAK void foo() {
00108  *      // a weak implementation of foo that can be overriden by a definition
00109  *      // without  __weak
00110  *  }
00111  *  @endcode
00112  */
00113 #ifndef MBED_WEAK
00114 #if defined(__ICCARM__)
00115 #define MBED_WEAK __weak
00116 #else
00117 #define MBED_WEAK __attribute__((weak))
00118 #endif
00119 #endif
00120 
00121 /** MBED_PURE
00122  *  Hint to the compiler that a function depends only on parameters
00123  *
00124  *  @code
00125  *  #include "mbed_toolchain.h"
00126  *
00127  *  MBED_PURE int foo(int arg){
00128  *      // no access to global variables
00129  *  }
00130  *  @endcode
00131  */
00132 #ifndef MBED_PURE
00133 #if defined(__GNUC__) || defined(__clang__) || defined(__CC_ARM)
00134 #define MBED_PURE __attribute__((const))
00135 #else
00136 #define MBED_PURE
00137 #endif
00138 #endif
00139 
00140 /** MBED_FORCEINLINE
00141  *  Declare a function that must always be inlined. Failure to inline
00142  *  such a function will result in an error.
00143  *
00144  *  @code
00145  *  #include "mbed_toolchain.h"
00146  *  
00147  *  MBED_FORCEINLINE void foo() {
00148  *  
00149  *  }
00150  *  @endcode
00151  */
00152 #ifndef MBED_FORCEINLINE
00153 #if defined(__GNUC__) || defined(__clang__) || defined(__CC_ARM)
00154 #define MBED_FORCEINLINE static inline __attribute__((always_inline))
00155 #elif defined(__ICCARM__)
00156 #define MBED_FORCEINLINE _Pragma("inline=forced") static
00157 #else
00158 #define MBED_FORCEINLINE static inline
00159 #endif
00160 #endif
00161 
00162 /** MBED_NORETURN
00163  *  Declare a function that will never return.
00164  *
00165  *  @code
00166  *  #include "mbed_toolchain.h"
00167  *  
00168  *  MBED_NORETURN void foo() {
00169  *      // must never return
00170  *      while (1) {}
00171  *  }
00172  *  @endcode
00173  */
00174 #ifndef MBED_NORETURN
00175 #if defined(__GNUC__) || defined(__clang__) || defined(__CC_ARM)
00176 #define MBED_NORETURN __attribute__((noreturn))
00177 #elif defined(__ICCARM__)
00178 #define MBED_NORETURN __noreturn
00179 #else
00180 #define MBED_NORETURN
00181 #endif
00182 #endif
00183 
00184 /** MBED_UNREACHABLE
00185  *  An unreachable statement. If the statement is reached,
00186  *  behaviour is undefined. Useful in situations where the compiler
00187  *  cannot deduce the unreachability of code.
00188  *
00189  *  @code
00190  *  #include "mbed_toolchain.h"
00191  *
00192  *  void foo(int arg) {
00193  *      switch (arg) {
00194  *          case 1: return 1;
00195  *          case 2: return 2;
00196  *          ...
00197  *      }
00198  *      MBED_UNREACHABLE;
00199  *  }
00200  *  @endcode
00201  */
00202 #ifndef MBED_UNREACHABLE
00203 #if (defined(__GNUC__) || defined(__clang__)) && !defined(__CC_ARM)
00204 #define MBED_UNREACHABLE __builtin_unreachable()
00205 #else
00206 #define MBED_UNREACHABLE while (1)
00207 #endif
00208 #endif
00209 
00210 /** MBED_DEPRECATED("message string")
00211  *  Mark a function declaration as deprecated, if it used then a warning will be
00212  *  issued by the compiler possibly including the provided message. Note that not
00213  *  all compilers are able to display the message.
00214  *
00215  *  @code
00216  *  #include "mbed_toolchain.h"
00217  *  
00218  *  MBED_DEPRECATED("don't foo any more, bar instead")
00219  *  void foo(int arg);
00220  *  @endcode
00221  */
00222 #ifndef MBED_DEPRECATED
00223 #if defined(__CC_ARM)
00224 #define MBED_DEPRECATED(M) __attribute__((deprecated))
00225 #elif defined(__GNUC__) || defined(__clang__)
00226 #define MBED_DEPRECATED(M) __attribute__((deprecated(M)))
00227 #else
00228 #define MBED_DEPRECATED(M)
00229 #endif
00230 #endif
00231 
00232 /** MBED_DEPRECATED_SINCE("version", "message string")
00233  *  Mark a function declaration as deprecated, noting that the declaration was
00234  *  deprecated on the specified version. If the function is used then a warning
00235  *  will be issued by the compiler possibly including the provided message.
00236  *  Note that not all compilers are able to display this message.
00237  *
00238  *  @code
00239  *  #include "mbed_toolchain.h"
00240  *
00241  *  MBED_DEPRECATED_SINCE("mbed-os-5.1", "don't foo any more, bar instead")
00242  *  void foo(int arg);
00243  *  @endcode
00244  */
00245 #define MBED_DEPRECATED_SINCE(D, M) MBED_DEPRECATED(M " [since " D "]")
00246 
00247 /** MBED_CALLER_ADDR()
00248  * Returns the caller of the current function.
00249  *
00250  * @note
00251  * This macro is only implemented for GCC and ARMCC.
00252  *
00253  * @code
00254  * #include "mbed_toolchain.h"
00255  *
00256  * printf("This function was called from %p", MBED_CALLER_ADDR());
00257  * @endcode
00258  *
00259  * @return Address of the calling function
00260  */
00261 #ifndef MBED_CALLER_ADDR
00262 #if (defined(__GNUC__) || defined(__clang__)) && !defined(__CC_ARM)
00263 #define MBED_CALLER_ADDR() __builtin_extract_return_addr(__builtin_return_address(0))
00264 #elif defined(__CC_ARM)
00265 #define MBED_CALLER_ADDR() __builtin_return_address(0)
00266 #else
00267 #define MBED_CALLER_ADDR() (NULL)
00268 #endif
00269 #endif
00270 
00271 #ifndef MBED_SECTION
00272 #if (defined(__GNUC__) || defined(__clang__)) || defined(__CC_ARM)
00273 #define MBED_SECTION(name) __attribute__ ((section (name)))
00274 #elif defined(__ICCARM__)
00275 #define MBED_SECTION(name) _Pragma(MBED_STRINGIFY(location=name))
00276 #else
00277 #error "Missing MBED_SECTION directive"
00278 #endif
00279 #endif
00280 
00281 // FILEHANDLE declaration
00282 #if defined(TOOLCHAIN_ARM)
00283 #include <rt_sys.h>
00284 #endif
00285 
00286 #ifndef FILEHANDLE
00287 typedef int FILEHANDLE;
00288 #endif
00289 
00290 // Backwards compatibility
00291 #ifndef WEAK
00292 #define WEAK MBED_WEAK
00293 #endif
00294 
00295 #ifndef PACKED
00296 #define PACKED MBED_PACKED()
00297 #endif
00298 
00299 #ifndef EXTERN
00300 #define EXTERN extern
00301 #endif
00302 
00303 #endif
00304 
00305 /** @}*/