py/nlr: Factor out common NLR code to macro and generic funcs in nlr.c.

Each NLR implementation (Thumb, x86, x64, xtensa, setjmp) duplicates a lot
of the NLR code, specifically that dealing with pushing and popping the NLR
pointer to maintain the linked-list of NLR buffers.  This patch factors all
of that code out of the specific implementations into generic functions in
nlr.c, along with a helper macro in nlr.h.  This eliminates duplicated
code.
This commit is contained in:
Damien George 2017-12-28 16:46:30 +11:00
parent 5bf8e85fc8
commit b25f92160b
8 changed files with 76 additions and 103 deletions

51
py/nlr.c Normal file
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@ -0,0 +1,51 @@
/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013-2017 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "py/mpstate.h"
#if !MICROPY_NLR_SETJMP
// When not using setjmp, nlr_push_tail is called from inline asm so needs special c
#if MICROPY_NLR_X86 && (defined(_WIN32) || defined(__CYGWIN__))
// On these 32-bit platforms make sure nlr_push_tail doesn't have a leading undersco
unsigned int nlr_push_tail(nlr_buf_t *nlr) asm("nlr_push_tail");
#else
// LTO can't see inside inline asm functions so explicitly mark nlr_push_tail as use
__attribute__((used)) unsigned int nlr_push_tail(nlr_buf_t *nlr);
#endif
#endif
unsigned int nlr_push_tail(nlr_buf_t *nlr) {
nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
nlr->prev = *top;
MP_NLR_SAVE_PYSTACK(nlr);
*top = nlr;
return 0; // normal return
}
void nlr_pop(void) {
nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
*top = (*top)->prev;
}

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@ -88,24 +88,29 @@ struct _nlr_buf_t {
#define MP_NLR_RESTORE_PYSTACK(nlr_buf) (void)nlr_buf
#endif
#if MICROPY_NLR_SETJMP
#include "py/mpstate.h"
// Helper macro to use at the start of a specific nlr_jump implementation
#define MP_NLR_JUMP_HEAD(val, top) \
nlr_buf_t **_top_ptr = &MP_STATE_THREAD(nlr_top); \
nlr_buf_t *top = *_top_ptr; \
if (top == NULL) { \
nlr_jump_fail(val); \
} \
top->ret_val = val; \
MP_NLR_RESTORE_PYSTACK(top); \
*_top_ptr = top->prev; \
NORETURN void nlr_setjmp_jump(void *val);
#if MICROPY_NLR_SETJMP
// 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 = MP_STATE_THREAD(nlr_top), \
MP_NLR_SAVE_PYSTACK(buf), \
MP_STATE_THREAD(nlr_top) = (buf), \
setjmp((buf)->jmpbuf))
#define nlr_pop() { MP_STATE_THREAD(nlr_top) = MP_STATE_THREAD(nlr_top)->prev; }
#define nlr_jump(val) nlr_setjmp_jump(val)
// For this case it is safe to call nlr_push_tail() first.
#define nlr_push(buf) (nlr_push_tail(buf), setjmp((buf)->jmpbuf))
#else
unsigned int nlr_push(nlr_buf_t *);
#endif
unsigned int nlr_push_tail(nlr_buf_t *top);
void nlr_pop(void);
NORETURN void nlr_jump(void *val);
#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

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@ -3,7 +3,7 @@
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
* Copyright (c) 2013-2017 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
@ -24,11 +24,11 @@
* THE SOFTWARE.
*/
#include "py/nlr.h"
#include "py/mpstate.h"
#if MICROPY_NLR_SETJMP
void nlr_setjmp_jump(void *val) {
void nlr_jump(void *val) {
nlr_buf_t **top_ptr = &MP_STATE_THREAD(nlr_top);
nlr_buf_t *top = *top_ptr;
if (top == NULL) {

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@ -3,7 +3,7 @@
*
* The MIT License (MIT)
*
* Copyright (c) 2013-2016 Damien P. George
* Copyright (c) 2013-2017 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
@ -82,29 +82,8 @@ __attribute__((naked)) unsigned int nlr_push(nlr_buf_t *nlr) {
#endif
}
__attribute__((used)) unsigned int nlr_push_tail(nlr_buf_t *nlr) {
nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
nlr->prev = *top;
MP_NLR_SAVE_PYSTACK(nlr);
*top = nlr;
return 0; // normal return
}
void nlr_pop(void) {
nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
*top = (*top)->prev;
}
NORETURN void nlr_jump(void *val) {
nlr_buf_t **top_ptr = &MP_STATE_THREAD(nlr_top);
nlr_buf_t *top = *top_ptr;
if (top == NULL) {
nlr_jump_fail(val);
}
top->ret_val = val;
MP_NLR_RESTORE_PYSTACK(top);
*top_ptr = top->prev;
MP_NLR_JUMP_HEAD(val, top)
__asm volatile (
"mov r0, %0 \n" // r0 points to nlr_buf

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@ -88,29 +88,8 @@ unsigned int nlr_push(nlr_buf_t *nlr) {
return 0; // needed to silence compiler warning
}
__attribute__((used)) unsigned int nlr_push_tail(nlr_buf_t *nlr) {
nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
nlr->prev = *top;
MP_NLR_SAVE_PYSTACK(nlr);
*top = nlr;
return 0; // normal return
}
void nlr_pop(void) {
nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
*top = (*top)->prev;
}
NORETURN void nlr_jump(void *val) {
nlr_buf_t **top_ptr = &MP_STATE_THREAD(nlr_top);
nlr_buf_t *top = *top_ptr;
if (top == NULL) {
nlr_jump_fail(val);
}
top->ret_val = val;
MP_NLR_RESTORE_PYSTACK(top);
*top_ptr = top->prev;
MP_NLR_JUMP_HEAD(val, top)
__asm volatile (
"movq %0, %%rcx \n" // %rcx points to nlr_buf

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@ -70,29 +70,8 @@ unsigned int nlr_push(nlr_buf_t *nlr) {
return 0; // needed to silence compiler warning
}
__attribute__((used)) unsigned int nlr_push_tail(nlr_buf_t *nlr) {
nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
nlr->prev = *top;
MP_NLR_SAVE_PYSTACK(nlr);
*top = nlr;
return 0; // normal return
}
void nlr_pop(void) {
nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
*top = (*top)->prev;
}
NORETURN void nlr_jump(void *val) {
nlr_buf_t **top_ptr = &MP_STATE_THREAD(nlr_top);
nlr_buf_t *top = *top_ptr;
if (top == NULL) {
nlr_jump_fail(val);
}
top->ret_val = val;
MP_NLR_RESTORE_PYSTACK(top);
*top_ptr = top->prev;
MP_NLR_JUMP_HEAD(val, top)
__asm volatile (
"mov %0, %%edx \n" // %edx points to nlr_buf

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@ -55,29 +55,8 @@ unsigned int nlr_push(nlr_buf_t *nlr) {
return 0; // needed to silence compiler warning
}
__attribute__((used)) unsigned int nlr_push_tail(nlr_buf_t *nlr) {
nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
nlr->prev = *top;
MP_NLR_SAVE_PYSTACK(nlr);
*top = nlr;
return 0; // normal return
}
void nlr_pop(void) {
nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
*top = (*top)->prev;
}
NORETURN void nlr_jump(void *val) {
nlr_buf_t **top_ptr = &MP_STATE_THREAD(nlr_top);
nlr_buf_t *top = *top_ptr;
if (top == NULL) {
nlr_jump_fail(val);
}
top->ret_val = val;
MP_NLR_RESTORE_PYSTACK(top);
*top_ptr = top->prev;
MP_NLR_JUMP_HEAD(val, top)
__asm volatile (
"mov.n a2, %0 \n" // a2 points to nlr_buf

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@ -103,6 +103,7 @@ endif
# py object files
PY_O_BASENAME = \
mpstate.o \
nlr.o \
nlrx86.o \
nlrx64.o \
nlrthumb.o \