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Diffstat (limited to 'contrib/syslinux-4.02/gpxe/src/include/compiler.h')
| -rw-r--r-- | contrib/syslinux-4.02/gpxe/src/include/compiler.h | 650 |
1 files changed, 650 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/include/compiler.h b/contrib/syslinux-4.02/gpxe/src/include/compiler.h new file mode 100644 index 0000000..ea81fc8 --- /dev/null +++ b/contrib/syslinux-4.02/gpxe/src/include/compiler.h @@ -0,0 +1,650 @@ +#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 <tt> -u obj_OBJECT </tt>. + * + */ + +/* Force visibility of all symbols to "hidden", i.e. inform gcc that + * all symbol references resolve strictly within our final binary. + * This avoids unnecessary PLT/GOT entries on x86_64. + * + * This is a stronger claim than specifying "-fvisibility=hidden", + * since it also affects symbols marked with "extern". + */ +#ifndef ASSEMBLY +#if __GNUC__ >= 4 +#pragma GCC visibility push(hidden) +#endif +#endif /* ASSEMBLY */ + +#undef _S1 +#undef _S2 +#undef _C1 +#undef _C2 + +/** Concatenate non-expanded arguments */ +#define _C1( x, y ) x ## y +/** Concatenate expanded arguments */ +#define _C2( x, y ) _C1 ( x, y ) + +/** Stringify non-expanded argument */ +#define _S1( x ) #x +/** Stringify expanded argument */ +#define _S2( x ) _S1 ( x ) + +/** + * @defgroup symmacros Macros to provide or require explicit symbols + * @{ + */ + +/** Provide a symbol within this object file */ +#ifdef ASSEMBLY +#define PROVIDE_SYMBOL( _sym ) \ + .globl _sym ; \ + .comm _sym, 0 +#else /* ASSEMBLY */ +#define PROVIDE_SYMBOL( _sym ) \ + char _sym[0] +#endif /* ASSEMBLY */ + +/** Require a symbol within this object file + * + * The symbol is referenced by a relocation in a discarded section, so + * if it is not available at link time the link will fail. + */ +#ifdef ASSEMBLY +#define REQUIRE_SYMBOL( _sym ) \ + .section ".discard", "a", @progbits ; \ + .extern _sym ; \ + .long _sym ; \ + .previous +#else /* ASSEMBLY */ +#define REQUIRE_SYMBOL( _sym ) \ + extern char _sym; \ + static char * _C2 ( _C2 ( __require_, _sym ), _C2 ( _, __LINE__ ) ) \ + __attribute__ (( section ( ".discard" ), used )) \ + = &_sym +#endif + +/** Request that a symbol be available at runtime + * + * The requested symbol is entered as undefined into the symbol table + * for this object, so the linker will pull in other object files as + * necessary to satisfy the reference. However, the undefined symbol + * is not referenced in any relocations, so the link can still succeed + * if no file contains it. + * + * A symbol passed to this macro may not be referenced anywhere + * else in the file. If you want to do that, see IMPORT_SYMBOL(). + */ +#ifdef ASSEMBLY +#define REQUEST_SYMBOL( _sym ) \ + .equ __need_ ## _sym, _sym +#else /* ASSEMBLY */ +#define REQUEST_SYMBOL( _sym ) \ + __asm__ ( ".equ\t__need_" #_sym ", " #_sym ) +#endif /* ASSEMBLY */ + +/** Set up a symbol to be usable in another file by IMPORT_SYMBOL() + * + * The symbol must already be marked as global. + */ +#define EXPORT_SYMBOL( _sym ) PROVIDE_SYMBOL ( __export_ ## _sym ) + +/** Make a symbol usable to this file if available at link time + * + * If no file passed to the linker contains the symbol, it will have + * @c NULL value to future uses. Keep in mind that the symbol value is + * really the @e address of a variable or function; see the code + * snippet below. + * + * In C using IMPORT_SYMBOL, you must specify the declaration as the + * second argument, for instance + * + * @code + * IMPORT_SYMBOL ( my_func, int my_func ( int arg ) ); + * IMPORT_SYMBOL ( my_var, int my_var ); + * + * void use_imports ( void ) { + * if ( my_func && &my_var ) + * my_var = my_func ( my_var ); + * } + * @endcode + * + * GCC considers a weak declaration to override a strong one no matter + * which comes first, so it is safe to include a header file declaring + * the imported symbol normally, but providing the declaration to + * IMPORT_SYMBOL is still required. + * + * If no EXPORT_SYMBOL declaration exists for the imported symbol in + * another file, the behavior will be most likely be identical to that + * for an unavailable symbol. + */ +#ifdef ASSEMBLY +#define IMPORT_SYMBOL( _sym ) \ + REQUEST_SYMBOL ( __export_ ## _sym ) ; \ + .weak _sym +#else /* ASSEMBLY */ +#define IMPORT_SYMBOL( _sym, _decl ) \ + REQUEST_SYMBOL ( __export_ ## _sym ) ; \ + extern _decl __attribute__ (( weak )) +#endif + +/** @} */ + +/** + * @defgroup objmacros Macros to provide or require explicit objects + * @{ + */ + +#define PREFIX_OBJECT( _prefix ) _C2 ( _prefix, OBJECT ) +#define OBJECT_SYMBOL PREFIX_OBJECT ( obj_ ) +#define REQUEST_EXPANDED( _sym ) REQUEST_SYMBOL ( _sym ) +#define CONFIG_SYMBOL PREFIX_OBJECT ( obj_config_ ) + +/** Always provide the symbol for the current object (defined by -DOBJECT) */ +PROVIDE_SYMBOL ( OBJECT_SYMBOL ); + +/** Pull in an object-specific configuration file if available */ +REQUEST_EXPANDED ( CONFIG_SYMBOL ); + +/** Explicitly require another object */ +#define REQUIRE_OBJECT( _obj ) REQUIRE_SYMBOL ( obj_ ## _obj ) + +/** Pull in another object if it exists */ +#define REQUEST_OBJECT( _obj ) REQUEST_SYMBOL ( obj_ ## _obj ) + +/** @} */ + +/** Select file identifier for errno.h (if used) */ +#define ERRFILE PREFIX_OBJECT ( ERRFILE_ ) + +/** + * @defgroup weakmacros Macros to manage weak symbol definitions + * + * Weak symbols allow one to reference a function in another file + * without necessarily requiring that file to be linked in. In their + * native form, the function will be @c NULL if its file is not linked + * in; these macros provide an inline wrapper that returns an + * appropriate error indication or default value. + * + * @{ + */ +#ifndef ASSEMBLY + +/** Mangle @a name into its weakly-referenced implementation */ +#define __weak_impl( name ) _w_ ## name + +/** + * Declare a weak function with inline safety wrapper + * + * @v ret Return type of weak function + * @v name Name of function to expose + * @v proto Parenthesized list of arguments with types + * @v args Parenthesized list of argument names + * @v dfl Value to return if weak function is not available + */ +#define __weak_decl( ret, name, proto, args, dfl ) \ + ret __weak_impl( name ) proto __attribute__ (( weak )); \ + static inline ret name proto { \ + if ( __weak_impl( name ) ) \ + return __weak_impl( name ) args; \ + return dfl; \ + } + +#endif +/** @} */ + +/** @defgroup dbg Debugging infrastructure + * @{ + */ +#ifndef ASSEMBLY + +/** @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. + * + */ + +/* + * 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_ ) + +/** printf() for debugging + * + * This function exists so that the DBG() macros can expand to + * printf() calls without dragging the printf() prototype into scope. + * + * As far as the compiler is concerned, dbg_printf() and printf() are + * completely unrelated calls; it's only at the assembly stage that + * references to the dbg_printf symbol are collapsed into references + * to the printf symbol. + */ +extern int __attribute__ (( format ( printf, 1, 2 ) )) +dbg_printf ( const char *fmt, ... ) asm ( "printf" ); + +extern void dbg_autocolourise ( unsigned long id ); +extern void dbg_decolourise ( void ); +extern void dbg_hex_dump_da ( unsigned long dispaddr, + const void *data, unsigned long len ); + +#if DEBUG_SYMBOL +#define DBGLVL_MAX DEBUG_SYMBOL +#else +#define DBGLVL_MAX 0 +#endif + +/* Allow for selective disabling of enabled debug levels */ +#if DBGLVL_MAX +int __debug_disable; +#define DBGLVL ( DBGLVL_MAX & ~__debug_disable ) +#define DBG_DISABLE( level ) do { \ + __debug_disable |= ( (level) & DBGLVL_MAX ); \ + } while ( 0 ) +#define DBG_ENABLE( level ) do { \ + __debug_disable &= ~( (level) & DBGLVL_MAX ); \ + } while ( 0 ) +#else +#define DBGLVL 0 +#define DBG_DISABLE( level ) do { } while ( 0 ) +#define DBG_ENABLE( level ) do { } while ( 0 ) +#endif + +#define DBGLVL_LOG 1 +#define DBG_LOG ( DBGLVL & DBGLVL_LOG ) +#define DBGLVL_EXTRA 2 +#define DBG_EXTRA ( DBGLVL & DBGLVL_EXTRA ) +#define DBGLVL_PROFILE 4 +#define DBG_PROFILE ( DBGLVL & DBGLVL_PROFILE ) +#define DBGLVL_IO 8 +#define DBG_IO ( DBGLVL & DBGLVL_IO ) + +/** + * Print debugging message if we are at a certain debug level + * + * @v level Debug level + * @v ... printf() argument list + */ +#define DBG_IF( level, ... ) do { \ + if ( DBG_ ## level ) { \ + dbg_printf ( __VA_ARGS__ ); \ + } \ + } while ( 0 ) + +/** + * Print a hex dump if we are at a certain debug level + * + * @v level Debug level + * @v dispaddr Display address + * @v data Data to print + * @v len Length of data + */ +#define DBG_HDA_IF( level, dispaddr, data, len ) do { \ + if ( DBG_ ## level ) { \ + union { \ + unsigned long ul; \ + typeof ( dispaddr ) raw; \ + } da; \ + da.raw = dispaddr; \ + dbg_hex_dump_da ( da.ul, data, len ); \ + } \ + } while ( 0 ) + +/** + * Print a hex dump if we are at a certain debug level + * + * @v level Debug level + * @v data Data to print + * @v len Length of data + */ +#define DBG_HD_IF( level, data, len ) do { \ + const void *_data = data; \ + DBG_HDA_IF ( level, _data, _data, len ); \ + } while ( 0 ) + +/** + * Select colour for debug messages if we are at a certain debug level + * + * @v level Debug level + * @v id Message stream ID + */ +#define DBG_AC_IF( level, id ) do { \ + if ( DBG_ ## level ) { \ + union { \ + unsigned long ul; \ + typeof ( id ) raw; \ + } dbg_stream; \ + dbg_stream.raw = id; \ + dbg_autocolourise ( dbg_stream.ul ); \ + } \ + } while ( 0 ) + +/** + * Revert colour for debug messages if we are at a certain debug level + * + * @v level Debug level + */ +#define DBG_DC_IF( level ) do { \ + if ( DBG_ ## level ) { \ + dbg_decolourise(); \ + } \ + } while ( 0 ) + +/* Autocolourising versions of the DBGxxx_IF() macros */ + +#define DBGC_IF( level, id, ... ) do { \ + DBG_AC_IF ( level, id ); \ + DBG_IF ( level, __VA_ARGS__ ); \ + DBG_DC_IF ( level ); \ + } while ( 0 ) + +#define DBGC_HDA_IF( level, id, ... ) do { \ + DBG_AC_IF ( level, id ); \ + DBG_HDA_IF ( level, __VA_ARGS__ ); \ + DBG_DC_IF ( level ); \ + } while ( 0 ) + +#define DBGC_HD_IF( level, id, ... ) do { \ + DBG_AC_IF ( level, id ); \ + DBG_HD_IF ( level, __VA_ARGS__ ); \ + DBG_DC_IF ( level ); \ + } while ( 0 ) + +/* Versions of the DBGxxx_IF() macros that imply DBGxxx_IF( LOG, ... )*/ + +#define DBG( ... ) DBG_IF ( LOG, __VA_ARGS__ ) +#define DBG_HDA( ... ) DBG_HDA_IF ( LOG, __VA_ARGS__ ) +#define DBG_HD( ... ) DBG_HD_IF ( LOG, __VA_ARGS__ ) +#define DBGC( ... ) DBGC_IF ( LOG, __VA_ARGS__ ) +#define DBGC_HDA( ... ) DBGC_HDA_IF ( LOG, __VA_ARGS__ ) +#define DBGC_HD( ... ) DBGC_HD_IF ( LOG, __VA_ARGS__ ) + +/* Versions of the DBGxxx_IF() macros that imply DBGxxx_IF( EXTRA, ... )*/ + +#define DBG2( ... ) DBG_IF ( EXTRA, __VA_ARGS__ ) +#define DBG2_HDA( ... ) DBG_HDA_IF ( EXTRA, __VA_ARGS__ ) +#define DBG2_HD( ... ) DBG_HD_IF ( EXTRA, __VA_ARGS__ ) +#define DBGC2( ... ) DBGC_IF ( EXTRA, __VA_ARGS__ ) +#define DBGC2_HDA( ... ) DBGC_HDA_IF ( EXTRA, __VA_ARGS__ ) +#define DBGC2_HD( ... ) DBGC_HD_IF ( EXTRA, __VA_ARGS__ ) + +/* Versions of the DBGxxx_IF() macros that imply DBGxxx_IF( PROFILE, ... )*/ + +#define DBGP( ... ) DBG_IF ( PROFILE, __VA_ARGS__ ) +#define DBGP_HDA( ... ) DBG_HDA_IF ( PROFILE, __VA_ARGS__ ) +#define DBGP_HD( ... ) DBG_HD_IF ( PROFILE, __VA_ARGS__ ) +#define DBGCP( ... ) DBGC_IF ( PROFILE, __VA_ARGS__ ) +#define DBGCP_HDA( ... ) DBGC_HDA_IF ( PROFILE, __VA_ARGS__ ) +#define DBGCP_HD( ... ) DBGC_HD_IF ( PROFILE, __VA_ARGS__ ) + +/* Versions of the DBGxxx_IF() macros that imply DBGxxx_IF( IO, ... )*/ + +#define DBGIO( ... ) DBG_IF ( IO, __VA_ARGS__ ) +#define DBGIO_HDA( ... ) DBG_HDA_IF ( IO, __VA_ARGS__ ) +#define DBGIO_HD( ... ) DBG_HD_IF ( IO, __VA_ARGS__ ) +#define DBGCIO( ... ) DBGC_IF ( IO, __VA_ARGS__ ) +#define DBGCIO_HDA( ... ) DBGC_HDA_IF ( IO, __VA_ARGS__ ) +#define DBGCIO_HD( ... ) DBGC_HD_IF ( IO, __VA_ARGS__ ) + + +#if DEBUG_SYMBOL == 0 +#define NDEBUG +#endif + +#endif /* ASSEMBLY */ +/** @} */ + +/** @defgroup attrs Miscellaneous attributes + * @{ + */ +#ifndef ASSEMBLY + +/** Declare a data structure as packed. */ +#define PACKED __attribute__ (( packed )) + +/** Declare a variable or data structure as unused. */ +#define __unused __attribute__ (( unused )) + +/** + * Declare a function as pure - i.e. without side effects + */ +#define __pure __attribute__ (( pure )) + +/** + * Declare a function as const - i.e. it does not access global memory + * (including dereferencing pointers passed to it) at all. + * Must also not call any non-const functions. + */ +#define __const __attribute__ (( const )) + +/** + * Declare a function's pointer parameters as non-null - i.e. force + * compiler to check pointers at compile time and enable possible + * optimizations based on that fact + */ +#define __nonnull __attribute__ (( nonnull )) + +/** + * Declare a pointer returned by a function as a unique memory address + * as returned by malloc-type functions. + */ +#define __malloc __attribute__ (( malloc )) + +/** + * Declare a function as used. + * + * Necessary only if the function is called only from assembler code. + */ +#define __used __attribute__ (( used )) + +/** Declare a data structure to be aligned with 16-byte alignment */ +#define __aligned __attribute__ (( aligned ( 16 ) )) + +/** Declare a function to be always inline */ +#define __always_inline __attribute__ (( always_inline )) + +/** + * 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" ) __aligned + +#endif /* ASSEMBLY */ +/** @} */ + +/** + * Optimisation barrier + */ +#ifndef ASSEMBLY +#define barrier() __asm__ __volatile__ ( "" : : : "memory" ) +#endif /* ASSEMBLY */ + +/** + * @defgroup licences Licence declarations + * + * For reasons that are partly historical, various different files + * within the gPXE codebase have differing licences. + * + * @{ + */ + +/** Declare a file as being in the public domain + * + * This licence declaration is applicable when a file states itself to + * be in the public domain. + */ +#define FILE_LICENCE_PUBLIC_DOMAIN \ + PROVIDE_SYMBOL ( __licence_public_domain ) + +/** Declare a file as being under version 2 (or later) of the GNU GPL + * + * This licence declaration is applicable when a file states itself to + * be licensed under the GNU GPL; "either version 2 of the License, or + * (at your option) any later version". + */ +#define FILE_LICENCE_GPL2_OR_LATER \ + PROVIDE_SYMBOL ( __licence_gpl2_or_later ) + +/** Declare a file as being under version 2 of the GNU GPL + * + * This licence declaration is applicable when a file states itself to + * be licensed under version 2 of the GPL, and does not include the + * "or, at your option, any later version" clause. + */ +#define FILE_LICENCE_GPL2_ONLY \ + PROVIDE_SYMBOL ( __licence_gpl2_only ) + +/** Declare a file as being under any version of the GNU GPL + * + * This licence declaration is applicable when a file states itself to + * be licensed under the GPL, but does not specify a version. + * + * According to section 9 of the GPLv2, "If the Program does not + * specify a version number of this License, you may choose any + * version ever published by the Free Software Foundation". + */ +#define FILE_LICENCE_GPL_ANY \ + PROVIDE_SYMBOL ( __licence_gpl_any ) + +/** Declare a file as being under the three-clause BSD licence + * + * This licence declaration is applicable when a file states itself to + * be licensed under terms allowing redistribution in source and + * binary forms (with or without modification) provided that: + * + * redistributions of source code retain the copyright notice, + * list of conditions and any attached disclaimers + * + * redistributions in binary form reproduce the copyright notice, + * list of conditions and any attached disclaimers in the + * documentation and/or other materials provided with the + * distribution + * + * the name of the author is not used to endorse or promote + * products derived from the software without specific prior + * written permission + * + * It is not necessary for the file to explicitly state that it is + * under a "BSD" licence; only that the licensing terms be + * functionally equivalent to the standard three-clause BSD licence. + */ +#define FILE_LICENCE_BSD3 \ + PROVIDE_SYMBOL ( __licence_bsd3 ) + +/** Declare a file as being under the two-clause BSD licence + * + * This licence declaration is applicable when a file states itself to + * be licensed under terms allowing redistribution in source and + * binary forms (with or without modification) provided that: + * + * redistributions of source code retain the copyright notice, + * list of conditions and any attached disclaimers + * + * redistributions in binary form reproduce the copyright notice, + * list of conditions and any attached disclaimers in the + * documentation and/or other materials provided with the + * distribution + * + * It is not necessary for the file to explicitly state that it is + * under a "BSD" licence; only that the licensing terms be + * functionally equivalent to the standard two-clause BSD licence. + */ +#define FILE_LICENCE_BSD2 \ + PROVIDE_SYMBOL ( __licence_bsd2 ) + +/** Declare a file as being under the one-clause MIT-style licence + * + * This licence declaration is applicable when a file states itself to + * be licensed under terms allowing redistribution for any purpose + * with or without fee, provided that the copyright notice and + * permission notice appear in all copies. + */ +#define FILE_LICENCE_MIT \ + PROVIDE_SYMBOL ( __licence_mit ) + +/** Declare a particular licence as applying to a file */ +#define FILE_LICENCE( _licence ) FILE_LICENCE_ ## _licence + +/** @} */ + +/* This file itself is under GPLv2-or-later */ +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <bits/compiler.h> + +#endif /* COMPILER_H */ |