gpxe/src/include/compiler.h

   1 #ifndef COMPILER_H
   2 #define COMPILER_H
   3
   4 /*
   5  * Doxygen can't cope with some of the more esoteric areas of C, so we
   6  * make its life simpler.
   7  *
   8  */
   9 #ifdef DOXYGEN
  10 #define __attribute__(x)
  11 #endif
  12
  13 /** @file
  14  *
  15  * Global compiler definitions.
  16  *
  17  * This file is implicitly included by every @c .c file in Etherboot.
  18  * It defines global macros such as DBG().
  19  *
  20  * We arrange for each object to export the symbol @c obj_OBJECT
  21  * (where @c OBJECT is the object name, e.g. @c rtl8139) as a global
  22  * symbol, so that the linker can drag in selected object files from
  23  * the library using <tt> -u obj_OBJECT </tt>.
  24  *
  25  */
  26
  27 /* Not quite sure why cpp requires two levels of macro call in order
  28  * to actually expand OBJECT...
  29  */
  30 #undef _H1
  31 #define _H1( x, y ) x ## y
  32 #undef _H2
  33 #define _H2( x, y ) _H1 ( x, y )
  34 #define PREFIX_OBJECT(prefix) _H2 ( prefix, OBJECT )
  35 #define OBJECT_SYMBOL PREFIX_OBJECT(obj_)
  36 #undef _STR
  37 #define _STR(s) #s
  38 #undef _XSTR
  39 #define _XSTR(s) _STR(s)
  40 #define OBJECT_SYMBOL_STR _XSTR ( OBJECT_SYMBOL )
  41
  42 #ifdef ASSEMBLY
  43
  44         .globl  OBJECT_SYMBOL
  45         .equ    OBJECT_SYMBOL, 0
  46
  47 #else /* ASSEMBLY */
  48
  49 __asm__ ( ".globl\t" OBJECT_SYMBOL_STR );
  50 __asm__ ( ".equ\t" OBJECT_SYMBOL_STR ", 0" );
  51
  52 /**
  53  * Drag in an object by object name.
  54  *
  55  * Macro to allow objects to explicitly drag in other objects by
  56  * object name.  Used by config.c.
  57  *
  58  */
  59 #define REQUIRE_OBJECT(object) \
  60         __asm__ ( ".equ\tneed_" #object ", obj_" #object );
  61
  62 /** @def DBG
  63  *
  64  * Print a debugging message.
  65  *
  66  * The debug level is set at build time by specifying the @c DEBUG=
  67  * parameter on the @c make command line.  For example, to enable
  68  * debugging for the PCI bus functions (in pci.c) in a @c .dsk image
  69  * for the @c rtl8139 card, you could use the command line
  70  *
  71  * @code
  72  *
  73  *   make bin/rtl8139.dsk DEBUG=pci
  74  *
  75  * @endcode
  76  *
  77  * This will enable the debugging statements (DBG()) in pci.c.  If
  78  * debugging is not enabled, DBG() statements will be ignored.
  79  *
  80  * You can enable debugging in several objects simultaneously by
  81  * separating them with commas, as in
  82  *
  83  * @code
  84  *
  85  *   make bin/rtl8139.dsk DEBUG=pci,buffer,heap
  86  *
  87  * @endcode
  88  *
  89  * You can increase the debugging level for an object by specifying it
  90  * with @c :N, where @c N is the level, as in
  91  *
  92  * @code
  93  *
  94  *   make bin/rtl8139.dsk DEBUG=pci,buffer:2,heap
  95  *
  96  * @endcode
  97  *
  98  * which would enable debugging for the PCI, buffer-handling and
  99  * heap-allocation code, with the buffer-handling code at level 2.
 100  *
 101  */
 102
 103 /*
 104  * If debug_OBJECT is set to a true value, the macro DBG(...) will
 105  * expand to printf(...) when compiling OBJECT, and the symbol
 106  * DEBUG_LEVEL will be inserted into the object file.
 107  *
 108  */
 109 #define DEBUG_SYMBOL PREFIX_OBJECT(debug_)
 110
 111 #if DEBUG_SYMBOL
 112 #define DEBUG_SYMBOL_STR _XSTR ( DEBUG_SYMBOL )
 113 __asm__ ( ".equ\tDBGLVL, " DEBUG_SYMBOL_STR );
 114 #endif
 115
 116 /** printf() for debugging
 117  *
 118  * This function exists so that the DBG() macros can expand to
 119  * printf() calls without dragging the printf() prototype into scope.
 120  *
 121  * As far as the compiler is concerned, dbg_printf() and printf() are
 122  * completely unrelated calls; it's only at the assembly stage that
 123  * references to the dbg_printf symbol are collapsed into references
 124  * to the printf symbol.
 125  */
 126 extern int __attribute__ (( format ( printf, 1, 2 ) ))
 127 dbg_printf ( const char *fmt, ... ) asm ( "printf" );
 128
 129 extern void dbg_autocolourise ( unsigned long id );
 130 extern void dbg_decolourise ( void );
 131 extern void dbg_hex_dump_da ( unsigned long dispaddr,
 132                               const void *data, unsigned long len );
 133
 134 /* Compatibility with existing Makefile */
 135 #if DEBUG_SYMBOL
 136 #define DBGLVL DEBUG_SYMBOL
 137 #else
 138 #define DBGLVL 0
 139 #endif
 140
 141 #define DBGLVL_LOG      1
 142 #define DBG_LOG         ( DBGLVL & DBGLVL_LOG )
 143 #define DBGLVL_EXTRA    2
 144 #define DBG_EXTRA       ( DBGLVL & DBGLVL_EXTRA )
 145 #define DBGLVL_PROFILE  4
 146 #define DBG_PROFILE     ( DBGLVL & DBGLVL_PROFILE )
 147 #define DBGLVL_IO       8
 148 #define DBG_IO          ( DBGLVL & DBGLVL_IO )
 149
 150 /**
 151  * Print debugging message if we are at a certain debug level
 152  *
 153  * @v level             Debug level
 154  * @v ...               printf() argument list
 155  */
 156 #define DBG_IF( level, ... ) do {                               \
 157                 if ( DBG_ ## level ) {                          \
 158                         dbg_printf ( __VA_ARGS__ );             \
 159                 }                                               \
 160         } while ( 0 )
 161
 162 /**
 163  * Print a hex dump if we are at a certain debug level
 164  *
 165  * @v level             Debug level
 166  * @v dispaddr          Display address
 167  * @v data              Data to print
 168  * @v len               Length of data
 169  */
 170 #define DBG_HDA_IF( level, dispaddr, data, len )  do {          \
 171                 if ( DBG_ ## level ) {                          \
 172                         union {                                 \
 173                                 unsigned long ul;               \
 174                                 typeof ( dispaddr ) raw;        \
 175                         } da;                                   \
 176                         da.raw = dispaddr;                      \
 177                         dbg_hex_dump_da ( da.ul, data, len );   \
 178                 }                                               \
 179         } while ( 0 )
 180
 181 /**
 182  * Print a hex dump if we are at a certain debug level
 183  *
 184  * @v level             Debug level
 185  * @v data              Data to print
 186  * @v len               Length of data
 187  */
 188 #define DBG_HD_IF( level, data, len ) do {                      \
 189                 DBG_HDA_IF ( level, data, data, len );          \
 190         } while ( 0 )
 191
 192 /**
 193  * Select colour for debug messages if we are at a certain debug level
 194  *
 195  * @v level             Debug level
 196  * @v id                Message stream ID
 197  */
 198 #define DBG_AC_IF( level, id ) do {                             \
 199                 if ( DBG_ ## level ) {                          \
 200                         union {                                 \
 201                                 unsigned long ul;               \
 202                                 typeof ( id ) raw;              \
 203                         } dbg_stream;                           \
 204                         dbg_stream.raw = id;                    \
 205                         dbg_autocolourise ( dbg_stream.ul );    \
 206                 }                                               \
 207         } while ( 0 )
 208
 209 /**
 210  * Revert colour for debug messages if we are at a certain debug level
 211  *
 212  * @v level             Debug level
 213  */
 214 #define DBG_DC_IF( level ) do {                                 \
 215                 if ( DBG_ ## level ) {                          \
 216                         dbg_decolourise();                      \
 217                 }                                               \
 218         } while ( 0 )
 219
 220 /* Autocolourising versions of the DBGxxx_IF() macros */
 221
 222 #define DBGC_IF( level, id, ... ) do {                          \
 223                 DBG_AC_IF ( level, id );                        \
 224                 DBG_IF ( level, __VA_ARGS__ );                  \
 225                 DBG_DC_IF ( level );                            \
 226         } while ( 0 )
 227
 228 #define DBGC_HDA_IF( level, id, ... ) do {                      \
 229                 DBG_AC_IF ( level, id );                        \
 230                 DBG_HDA_IF ( level, __VA_ARGS__ );              \
 231                 DBG_DC_IF ( level );                            \
 232         } while ( 0 )
 233
 234 #define DBGC_HD_IF( level, id, ... ) do {                       \
 235                 DBG_AC_IF ( level, id );                        \
 236                 DBG_HD_IF ( level, __VA_ARGS__ );               \
 237                 DBG_DC_IF ( level );                            \
 238         } while ( 0 )
 239
 240 /* Versions of the DBGxxx_IF() macros that imply DBGxxx_IF( LOG, ... )*/
 241
 242 #define DBG( ... )              DBG_IF          ( LOG, __VA_ARGS__ )
 243 #define DBG_HDA( ... )          DBG_HDA_IF      ( LOG, __VA_ARGS__ )
 244 #define DBG_HD( ... )           DBG_HD_IF       ( LOG, __VA_ARGS__ )
 245 #define DBGC( ... )             DBGC_IF         ( LOG, __VA_ARGS__ )
 246 #define DBGC_HDA( ... )         DBGC_HDA_IF     ( LOG, __VA_ARGS__ )
 247 #define DBGC_HD( ... )          DBGC_HD_IF      ( LOG, __VA_ARGS__ )
 248
 249 /* Versions of the DBGxxx_IF() macros that imply DBGxxx_IF( EXTRA, ... )*/
 250
 251 #define DBG2( ... )             DBG_IF          ( EXTRA, __VA_ARGS__ )
 252 #define DBG2_HDA( ... )         DBG_HDA_IF      ( EXTRA, __VA_ARGS__ )
 253 #define DBG2_HD( ... )          DBG_HD_IF       ( EXTRA, __VA_ARGS__ )
 254 #define DBGC2( ... )            DBGC_IF         ( EXTRA, __VA_ARGS__ )
 255 #define DBGC2_HDA( ... )        DBGC_HDA_IF     ( EXTRA, __VA_ARGS__ )
 256 #define DBGC2_HD( ... )         DBGC_HD_IF      ( EXTRA, __VA_ARGS__ )
 257
 258 /* Versions of the DBGxxx_IF() macros that imply DBGxxx_IF( PROFILE, ... )*/
 259
 260 #define DBGP( ... )             DBG_IF          ( PROFILE, __VA_ARGS__ )
 261 #define DBGP_HDA( ... )         DBG_HDA_IF      ( PROFILE, __VA_ARGS__ )
 262 #define DBGP_HD( ... )          DBG_HD_IF       ( PROFILE, __VA_ARGS__ )
 263 #define DBGCP( ... )            DBGC_IF         ( PROFILE, __VA_ARGS__ )
 264 #define DBGCP_HDA( ... )        DBGC_HDA_IF     ( PROFILE, __VA_ARGS__ )
 265 #define DBGCP_HD( ... )         DBGC_HD_IF      ( PROFILE, __VA_ARGS__ )
 266
 267 /* Versions of the DBGxxx_IF() macros that imply DBGxxx_IF( IO, ... )*/
 268
 269 #define DBGIO( ... )            DBG_IF          ( IO, __VA_ARGS__ )
 270 #define DBGIO_HDA( ... )        DBG_HDA_IF      ( IO, __VA_ARGS__ )
 271 #define DBGIO_HD( ... )         DBG_HD_IF       ( IO, __VA_ARGS__ )
 272 #define DBGCIO( ... )           DBGC_IF         ( IO, __VA_ARGS__ )
 273 #define DBGCIO_HDA( ... )       DBGC_HDA_IF     ( IO, __VA_ARGS__ )
 274 #define DBGCIO_HD( ... )        DBGC_HD_IF      ( IO, __VA_ARGS__ )
 275
 276
 277 #if DEBUG_SYMBOL == 0
 278 #define NDEBUG
 279 #endif
 280
 281 /** Select file identifier for errno.h (if used) */
 282 #define ERRFILE PREFIX_OBJECT ( ERRFILE_ )
 283
 284 /** Declare a data structure as packed. */
 285 #define PACKED __attribute__ (( packed ))
 286
 287 /** Declare a variable or data structure as unused. */
 288 #define __unused __attribute__ (( unused ))
 289
 290 /** Apply standard C calling conventions */
 291 #define __cdecl __attribute__ (( cdecl , regparm(0) ))
 292
 293 /**
 294  * Declare a function as pure - i.e. without side effects
 295  */
 296 #define __pure __attribute__ (( pure ))
 297
 298 /**
 299  * Declare a function as const - i.e. it does not access global memory
 300  * (including dereferencing pointers passed to it) at all.
 301  * Must also not call any non-const functions.
 302  */
 303 #define __const __attribute__ (( const ))
 304
 305 /**
 306  * Declare a function's pointer parameters as non-null - i.e. force
 307  * compiler to check pointers at compile time and enable possible
 308  * optimizations based on that fact
 309  */
 310 #define __nonnull __attribute__ (( nonnull ))
 311
 312 /**
 313  * Declare a pointer returned by a function as a unique memory address
 314  * as returned by malloc-type functions.
 315  */
 316 #define __malloc __attribute__ (( malloc ))
 317
 318 /**
 319  * Declare a function as used.
 320  *
 321  * Necessary only if the function is called only from assembler code.
 322  */
 323 #define __used __attribute__ (( used ))
 324
 325 /** Declare a data structure to be aligned with 16-byte alignment */
 326 #define __aligned __attribute__ (( aligned ( 16 ) ))
 327
 328 /**
 329  * Shared data.
 330  *
 331  * To save space in the binary when multiple-driver images are
 332  * compiled, uninitialised data areas can be shared between drivers.
 333  * This will typically be used to share statically-allocated receive
 334  * and transmit buffers between drivers.
 335  *
 336  * Use as e.g.
 337  *
 338  * @code
 339  *
 340  *   struct {
 341  *      char    rx_buf[NUM_RX_BUF][RX_BUF_SIZE];
 342  *      char    tx_buf[TX_BUF_SIZE];
 343  *   } my_static_data __shared;
 344  *
 345  * @endcode
 346  *
 347  */
 348 #define __shared __asm__ ( "_shared_bss" )
 349
 350 /**
 351  * Optimisation barrier
 352  */
 353 #define barrier() __asm__ __volatile__ ( "" : : : "memory" )
 354
 355 #endif /* ASSEMBLY */
 356
 357 #endif /* COMPILER_H */