https://github.com/abertschi/setjmp
hand-knitted try/catch mechanism for c using setjmp.h
https://github.com/abertschi/setjmp
Last synced: about 2 months ago
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hand-knitted try/catch mechanism for c using setjmp.h
- Host: GitHub
- URL: https://github.com/abertschi/setjmp
- Owner: abertschi
- Created: 2018-01-27T19:31:18.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2018-01-30T17:50:26.000Z (over 7 years ago)
- Last Synced: 2025-02-01T09:22:47.270Z (4 months ago)
- Language: C
- Size: 15.6 KB
- Stars: 1
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# Exception Handling with setjmp.h in C
- Supports nested try_catch clauses
- Reading: https://en.m.wikipedia.org/wiki/Setjmp.h
## Syntax
```c
try_catch({
// try block
raise(42); // boom!
}, {
// catch block
// exception_code (int) contains exception code (42 here)
});
```
## Limitations
- `code` in `raise(code)` cannot be 0
- `raise(code)` can only be called within a `try_catch` block
- try clause is no free ride; catch clause overhead even if catch is not taken
## Implementation
```c
/**
* hand-knitted try/catch mechanism for c using setjmp.
* Andrin Bertschi
*
*/
#include
#include
#include
static jmp_buf exception_ctx;
static int exception_code;
#define raise(errcode) \
longjmp(exception_ctx, errcode);
#define try_catch(t, c) \
{ \
jmp_buf buf; \
memcpy(buf, exception_ctx, sizeof(buf)); \
if(exception_code = setjmp(exception_ctx), exception_code) \
{c} \
else \
{t} \
memcpy(exception_ctx, buf, sizeof(buf)); \
}
int main(int argc, char *argv[argc])
{
try_catch({
printf("in try block 0\n");
try_catch({
printf("in try block 1\n");
printf("raising exception in try block 1\n");
raise(42);
printf("i am never shown\n");
},{
printf("in catch block 1\n");
printf("exception is: %d\n", exception_code);
});
printf("after try_catch block 1 \n");
printf("raising exception in try block 0\n");
raise(43);
printf("i am never shown\n");
},{
printf("in catch block 0\n");
printf("exception is: %d\n", exception_code);
});
printf("after try_catch block 0 \n");
return 0;
}
```
```
# will print:
in try block 0
in try block 1
raising exception in try block 1
in catch block 1
exception is: 42
after try_catch block 1
raising exception in try block 0
in catch block 0
exception is: 43
after try_catch block 0
```