1 /*++ 2 3 Copyright (c) 2004, Intel Corporation. All rights reserved.<BR> 4 This program and the accompanying materials 5 are licensed and made available under the terms and conditions of the BSD License 6 which accompanies this distribution. The full text of the license may be found at 7 http://opensource.org/licenses/bsd-license.php 8 9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 11 12 Module Name: 13 14 EfiStdArg.h 15 16 Abstract: 17 18 Support for variable length argument lists using the ANSI standard. 19 20 Since we are using the ANSI standard we used the standard nameing and 21 did not folow the coding convention 22 23 VA_LIST - typedef for argument list. 24 VA_START (VA_LIST Marker, argument before the ...) - Init Marker for use. 25 VA_END (VA_LIST Marker) - Clear Marker 26 VA_ARG (VA_LIST Marker, var arg size) - Use Marker to get an argumnet from 27 the ... list. You must know the size and pass it in this macro. 28 29 example: 30 31 UINTN 32 ExampleVarArg ( 33 IN UINTN NumberOfArgs, 34 ... 35 ) 36 { 37 VA_LIST Marker; 38 UINTN Index; 39 UINTN Result; 40 41 // 42 // Initialize the Marker 43 // 44 VA_START (Marker, NumberOfArgs); 45 for (Index = 0, Result = 0; Index < NumberOfArgs; Index++) { 46 // 47 // The ... list is a series of UINTN values, so average them up. 48 // 49 Result += VA_ARG (Marker, UINTN); 50 } 51 52 VA_END (Marker); 53 return Result 54 } 55 56 --*/ 57 58 #ifndef _EFISTDARG_H_ 59 #define _EFISTDARG_H_ 60 61 /** 62 Return the size of argument that has been aligned to sizeof (UINTN). 63 64 @param n The parameter size to be aligned. 65 66 @return The aligned size. 67 **/ 68 #define _INT_SIZE_OF(n) ((sizeof (n) + sizeof (UINTN) - 1) &~(sizeof (UINTN) - 1)) 69 70 #if defined(__CC_ARM) 71 // 72 // RVCT ARM variable argument list support. 73 // 74 75 /// 76 /// Variable used to traverse the list of arguments. This type can vary by 77 /// implementation and could be an array or structure. 78 /// 79 #ifdef __APCS_ADSABI 80 typedef int *va_list[1]; 81 #define VA_LIST va_list 82 #else 83 typedef struct __va_list { void *__ap; } va_list; 84 #define VA_LIST va_list 85 #endif 86 87 #define VA_START(Marker, Parameter) __va_start(Marker, Parameter) 88 89 #define VA_ARG(Marker, TYPE) __va_arg(Marker, TYPE) 90 91 #define VA_END(Marker) ((void)0) 92 93 #define VA_COPY(Dest, Start) __va_copy (Dest, Start) 94 95 #elif defined(__GNUC__) && !defined(NO_BUILTIN_VA_FUNCS) 96 // 97 // Use GCC built-in macros for variable argument lists. 98 // 99 100 /// 101 /// Variable used to traverse the list of arguments. This type can vary by 102 /// implementation and could be an array or structure. 103 /// 104 typedef __builtin_va_list VA_LIST; 105 106 #define VA_START(Marker, Parameter) __builtin_va_start (Marker, Parameter) 107 108 #define VA_ARG(Marker, TYPE) ((sizeof (TYPE) < sizeof (UINTN)) ? (TYPE)(__builtin_va_arg (Marker, UINTN)) : (TYPE)(__builtin_va_arg (Marker, TYPE))) 109 110 #define VA_END(Marker) __builtin_va_end (Marker) 111 112 #define VA_COPY(Dest, Start) __builtin_va_copy (Dest, Start) 113 114 #else 115 116 #ifndef VA_START 117 118 /// 119 /// Variable used to traverse the list of arguments. This type can vary by 120 /// implementation and could be an array or structure. 121 /// 122 typedef CHAR8 *VA_LIST; 123 124 /** 125 Retrieves a pointer to the beginning of a variable argument list, based on 126 the name of the parameter that immediately precedes the variable argument list. 127 128 This function initializes Marker to point to the beginning of the variable 129 argument list that immediately follows Parameter. The method for computing the 130 pointer to the next argument in the argument list is CPU-specific following the 131 EFIAPI ABI. 132 133 @param Marker The VA_LIST used to traverse the list of arguments. 134 @param Parameter The name of the parameter that immediately precedes 135 the variable argument list. 136 137 @return A pointer to the beginning of a variable argument list. 138 139 **/ 140 #define VA_START(Marker, Parameter) (Marker = (VA_LIST) ((UINTN) & (Parameter) + _INT_SIZE_OF (Parameter))) 141 142 /** 143 Returns an argument of a specified type from a variable argument list and updates 144 the pointer to the variable argument list to point to the next argument. 145 146 This function returns an argument of the type specified by TYPE from the beginning 147 of the variable argument list specified by Marker. Marker is then updated to point 148 to the next argument in the variable argument list. The method for computing the 149 pointer to the next argument in the argument list is CPU-specific following the EFIAPI ABI. 150 151 @param Marker VA_LIST used to traverse the list of arguments. 152 @param TYPE The type of argument to retrieve from the beginning 153 of the variable argument list. 154 155 @return An argument of the type specified by TYPE. 156 157 **/ 158 #define VA_ARG(Marker, TYPE) (*(TYPE *) ((Marker += _INT_SIZE_OF (TYPE)) - _INT_SIZE_OF (TYPE))) 159 160 /** 161 Terminates the use of a variable argument list. 162 163 This function initializes Marker so it can no longer be used with VA_ARG(). 164 After this macro is used, the only way to access the variable argument list is 165 by using VA_START() again. 166 167 @param Marker VA_LIST used to traverse the list of arguments. 168 169 **/ 170 #define VA_END(Marker) (Marker = (VA_LIST) 0) 171 172 #define VA_COPY(dest, src) ((void)((dest) = (src))) 173 174 #endif 175 176 #endif 177 178 #endif 179