1 /** @file 2 This file defines the macro setjmp, and declares the function longjmp 3 and the type jmp_buf, for bypassing the normal function call and return discipline. 4 5 Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR> 6 This program and the accompanying materials are licensed and made available under 7 the terms and conditions of the BSD License that accompanies this distribution. 8 The full text of the license may be found at 9 http://opensource.org/licenses/bsd-license. 10 11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 13 **/ 14 #ifndef _SETJMP_H 15 #define _SETJMP_H 16 #include <Library/BaseLib.h> 17 #include <sys/EfiCdefs.h> 18 19 /** jmp_buf is an array type suitable for holding the information needed to 20 restore a calling environment. The environment of a call to the setjmp 21 macro consists of information sufficient for a call to the longjmp function 22 to return execution to the correct block and invocation of that block, were 23 it called recursively. It does not include the state of the floating-point 24 status flags, of open files, or of any other component of the abstract 25 machine. 26 **/ 27 typedef BASE_LIBRARY_JUMP_BUFFER jmp_buf[1]; 28 29 /** The setjmp macro saves its calling environment in its jmp_buf argument for 30 later use by the longjmp function. 31 32 The Standard does not specify whether setjmp is a macro or an identifier 33 declared with external linkage. If a macro definition is suppressed in 34 order to access an actual function, or a program defines an external 35 identifier with the name setjmp, the behavior is undefined by the Standard. 36 37 @param[in,out] env A jmp_buf type object into which 38 the current environment is stored. 39 40 @return If the return is from a direct invocation, the setjmp macro 41 returns the value zero. If the return is from a call to the longjmp 42 function, the setjmp macro returns a nonzero value based upon the value 43 of the second argument to the longjmp function. 44 **/ 45 #define setjmp(env) (INTN)SetJump((env)) 46 47 /** The longjmp function restores the environment saved by the most recent 48 invocation of the setjmp macro in the same invocation of the program with 49 the corresponding jmp_buf argument. If there has been no such invocation, 50 or if the function containing the invocation of the setjmp macro has 51 terminated execution in the interim, or if the invocation of the setjmp 52 macro was within the scope of an identifier with variably modified type and 53 execution has left that scope in the interim, the behavior is undefined. 54 55 @param[in] env The jump buffer containing the environment to be returned to. 56 @param[in] val A non-zero value to be returned from setjmp. 57 58 @return After longjmp is completed, program execution continues as if the 59 corresponding invocation of the setjmp macro had just returned the value 60 specified by val. The longjmp function cannot cause the setjmp macro to 61 return the value 0; if val is 0, the setjmp macro returns the value 1. 62 **/ 63 extern void longjmp(jmp_buf env, int val); 64 65 #endif /* _SETJMP_H */ 66
