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pfalconpfalcon
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nlr: Add implementation using setjmp/longjmp.
Having an optimized asm implementation is good, but if we want portability, that's it.
1 parent a1c6720 commit 3a83b80

3 files changed

Lines changed: 36 additions & 1 deletion

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‎py/nlr.h‎

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

‎py/nlrsetjmp.c‎

Lines changed: 16 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,16 @@
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#include <setjmp.h>
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#include <stdio.h>
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#include "nlr.h"
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#if MICROPY_NLR_SETJMP
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nlr_buf_t *nlr_setjmp_top;
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void nlr_setjmp_jump(void *val) {
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nlr_buf_t *buf = nlr_setjmp_top;
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nlr_setjmp_top = buf->prev;
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buf->ret_val = val;
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longjmp(buf->jmpbuf, 1);
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}
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#endif

‎py/py.mk‎

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

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