#ifndef COMPILER_H #define COMPILER_H /* * Doxygen can't cope with some of the more esoteric areas of C, so we * make its life simpler. * */ #ifdef DOXYGEN #define __attribute__(x) #endif /** @file * * Global compiler definitions. * * This file is implicitly included by every @c .c file in Etherboot. * It defines global macros such as DBG(). * * We arrange for each object to export the symbol @c obj_OBJECT * (where @c OBJECT is the object name, e.g. @c rtl8139) as a global * symbol, so that the linker can drag in selected object files from * the library using -u obj_OBJECT . * */ /* Not quite sure why cpp requires two levels of macro call in order * to actually expand OBJECT... */ #undef _H1 #define _H1( x, y ) x ## y #undef _H2 #define _H2( x, y ) _H1 ( x, y ) #define PREFIX_OBJECT(prefix) _H2 ( prefix, OBJECT ) #define OBJECT_SYMBOL PREFIX_OBJECT(obj_) #undef _STR #define _STR(s) #s #undef _XSTR #define _XSTR(s) _STR(s) #define OBJECT_SYMBOL_STR _XSTR ( OBJECT_SYMBOL ) #ifdef ASSEMBLY .globl OBJECT_SYMBOL .equ OBJECT_SYMBOL, 0 #else /* ASSEMBLY */ __asm__ ( ".globl\t" OBJECT_SYMBOL_STR ); __asm__ ( ".equ\t" OBJECT_SYMBOL_STR ", 0" ); /** * Drag in an object by object name. * * Macro to allow objects to explicitly drag in other objects by * object name. Used by config.c. * */ #define REQUIRE_OBJECT(object) \ __asm__ ( ".equ\tneed_" #object ", obj_" #object ); /** @def DBG * * Print a debugging message. * * The debug level is set at build time by specifying the @c DEBUG= * parameter on the @c make command line. For example, to enable * debugging for the PCI bus functions (in pci.c) in a @c .dsk image * for the @c rtl8139 card, you could use the command line * * @code * * make bin/rtl8139.dsk DEBUG=pci * * @endcode * * This will enable the debugging statements (DBG()) in pci.c. If * debugging is not enabled, DBG() statements will be ignored. * * You can enable debugging in several objects simultaneously by * separating them with commas, as in * * @code * * make bin/rtl8139.dsk DEBUG=pci,buffer,heap * * @endcode * * You can increase the debugging level for an object by specifying it * with @c :N, where @c N is the level, as in * * @code * * make bin/rtl8139.dsk DEBUG=pci,buffer:2,heap * * @endcode * * which would enable debugging for the PCI, buffer-handling and * heap-allocation code, with the buffer-handling code at level 2. * */ /** @def DBG2 * * Print a level 2 debugging message. * * As for DBG(). DBG2() takes effect only when the debugging level is * 2 or greater. * */ /* * If debug_OBJECT is set to a true value, the macro DBG(...) will * expand to printf(...) when compiling OBJECT, and the symbol * DEBUG_LEVEL will be inserted into the object file. * */ #define DEBUG_SYMBOL PREFIX_OBJECT(debug_) #if DEBUG_SYMBOL #include "console.h" #define DEBUG_SYMBOL_STR _XSTR ( DEBUG_SYMBOL ) __asm__ ( ".equ\tDEBUG_LEVEL, " DEBUG_SYMBOL_STR ); #endif /** Do not print * * This function is used only for printf()-style format string * checking. The function body does not exist, and no reference to it * should ever appear in any compiled object. */ extern int __attribute__ (( format ( printf, 1, 2 ) )) __do_not_printf ( const char *fmt, ... ); #define DBG_PRINT(...) printf ( __VA_ARGS__ ) #define DBG_DISCARD(...) do { \ if ( 0 ) __do_not_printf ( __VA_ARGS__ ); \ } while ( 0 ) #define DBG DBG_DISCARD #define DBG2 DBG_DISCARD #if DEBUG_SYMBOL >= 1 #undef DBG #define DBG DBG_PRINT #endif #if DEBUG_SYMBOL >= 2 #undef DBG2 #define DBG2 DBG_PRINT #endif #if DEBUG_SYMBOL == 0 #define NDEBUG #endif /** Declare a data structure as packed. */ #define PACKED __attribute__ (( packed )) /** * Declare a variable or data structure as unused. * * Note that using #__unused on a static global variable (such as a * table structure as mentioned in tables.h) is necessary in order to * inhibit compiler warnings. * */ #define __unused __attribute__ (( unused )) /** * Declare a function as used. * * Necessary only if the function is called only from assembler code. * You cannot use this attribute for static global variables; use * #__unused instead. * */ #define __used __attribute__ (( used )) /** Declare a data structure to be aligned with 16-byte alignment */ #define __aligned __attribute__ (( aligned ( 16 ) )) /** * Shared data. * * To save space in the binary when multiple-driver images are * compiled, uninitialised data areas can be shared between drivers. * This will typically be used to share statically-allocated receive * and transmit buffers between drivers. * * Use as e.g. * * @code * * struct { * char rx_buf[NUM_RX_BUF][RX_BUF_SIZE]; * char tx_buf[TX_BUF_SIZE]; * } my_static_data __shared; * * @endcode * */ #define __shared __asm__ ( "_shared_bss" ) #endif /* ASSEMBLY */ #endif /* COMPILER_H */