nlr: Add implementation using setjmp/longjmp.

Having an optimized asm implementation is good, but if we want portability,
that's it.
This commit is contained in:
Paul Sokolovsky 2014-04-17 00:16:45 +03:00
parent a1c67206c8
commit 3a83b805fc
3 changed files with 36 additions and 1 deletions

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@ -2,12 +2,14 @@
// exception handling, basically a stack of setjmp/longjmp buffers
#include <limits.h>
#include <setjmp.h>
typedef struct _nlr_buf_t nlr_buf_t;
struct _nlr_buf_t {
// the entries here must all be machine word size
nlr_buf_t *prev;
void *ret_val;
#if !MICROPY_NLR_SETJMP
#if defined(__i386__)
void *regs[6];
#elif defined(__x86_64__)
@ -19,13 +21,29 @@ struct _nlr_buf_t {
#elif defined(__thumb2__)
void *regs[10];
#else
#error Unknown arch in nlr.h
#define MICROPY_NLR_SETJMP (1)
#warning "No native NLR support for this arch, using setjmp implementation"
#endif
#endif
#if MICROPY_NLR_SETJMP
jmp_buf jmpbuf;
#endif
};
#if MICROPY_NLR_SETJMP
extern nlr_buf_t *nlr_setjmp_top;
void nlr_setjmp_jump(void *val) __attribute__((noreturn));
// nlr_push() must be defined as a macro, because "The stack context will be
// invalidated if the function which called setjmp() returns."
#define nlr_push(buf) ((buf)->prev = nlr_setjmp_top, nlr_setjmp_top = (buf), setjmp((buf)->jmpbuf))
#define nlr_pop() { nlr_setjmp_top = nlr_setjmp_top->prev; }
#define nlr_jump(val) nlr_setjmp_jump(val)
#else
unsigned int nlr_push(nlr_buf_t *);
void nlr_pop(void);
void nlr_jump(void *val) __attribute__((noreturn));
#endif
// This must be implemented by a port. It's called by nlr_jump
// if no nlr buf has been pushed. It must not return, but rather

16
py/nlrsetjmp.c Normal file
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@ -0,0 +1,16 @@
#include <setjmp.h>
#include <stdio.h>
#include "nlr.h"
#if MICROPY_NLR_SETJMP
nlr_buf_t *nlr_setjmp_top;
void nlr_setjmp_jump(void *val) {
nlr_buf_t *buf = nlr_setjmp_top;
nlr_setjmp_top = buf->prev;
buf->ret_val = val;
longjmp(buf->jmpbuf, 1);
}
#endif

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@ -10,6 +10,7 @@ PY_O_BASENAME = \
nlrx86.o \
nlrx64.o \
nlrthumb.o \
nlrsetjmp.o \
malloc.o \
gc.o \
qstr.o \