Non-local goto as specified in ANSI C. More...
#include <config.h>
Include dependency graph for setjmp.h:
Go to the source code of this file.
Typedefs | |
| typedef int | jmp_buf[6] |
| Information stored for non-local jumps. More... | |
Functions | |
| int | setjmp (jmp_buf env) |
| Save execution context for non-local goto. More... | |
| void | longjmp (jmp_buf env, int val) |
| Non-local jump to saved machine context. More... | |
Detailed Description
Non-local goto as specified in ANSI C.
Definition in file setjmp.h.
Typedef Documentation
| typedef int jmp_buf[6] |
Information stored for non-local jumps.
Stores the machine status for non-local jumps. The H8/300 CPU has the following state information:
- 8 registers of 16 bit each (r0, r1, ..., r7)
- the program counter
- a condition code register of a single byte To allow execution of a longjmp we have to return to the state saved in a jmp_buf just like from a subroutine invocation. The machine description of gcc for the H8 says that r0,r1,r2,r3 are destroyed by a subroutine call. Therefore we need to save the condition code, the program counter of the caller (where we want to return), and the registers r4, r5, r6, r7. We are using 6 words for that and ignore a byte at restore time.
Function Documentation
| void longjmp | ( | jmp_buf | env, |
| int | val | ||
| ) |
Non-local jump to saved machine context.
Restores a machine context as saved via setjmp.
- Parameters
-
env the buffer of the saved machine status val the value to return from the setjmp function
| int setjmp | ( | jmp_buf | env | ) |
Save execution context for non-local goto.
Records the current machine status for a non-local goto. The saved status will be invalidated when returning from the stack frame where it was set.
- Parameters
-
env buffer for saved machine status
- Returns
- 0 when returning directly (after saving the state), or whatever was given to longjmp when returning via a non-local goto
