py: Move global variable nlr_top to one place, in a .c file.

This reduces dependency on assembler, and allows to consolidate global
variables in the future.

py/nlr.h

@@ -64,13 +64,14 @@ struct _nlr_buf_t {
 #endif
 };
 
+extern nlr_buf_t *nlr_top;
+
 #if MICROPY_NLR_SETJMP
-extern nlr_buf_t *nlr_setjmp_top;
 NORETURN void nlr_setjmp_jump(void *val);
 // 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_push(buf) ((buf)->prev = nlr_top, nlr_top = (buf), setjmp((buf)->jmpbuf))
+#define nlr_pop() { nlr_top = nlr_top->prev; }
 #define nlr_jump(val) nlr_setjmp_jump(val)
 #else
 unsigned int nlr_push(nlr_buf_t *);

py/nlrsetjmp.c

@@ -26,13 +26,14 @@
 
 #include "py/nlr.h"
 
+// this global variable is used for all nlr implementations
+nlr_buf_t *nlr_top;
+
 #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;
+    nlr_buf_t *buf = nlr_top;
+    nlr_top = buf->prev;
     buf->ret_val = val;
     longjmp(buf->jmpbuf, 1);
 }

py/nlrthumb.S

@@ -59,7 +59,7 @@ nlr_push:
     str     r11, [r0, #40]          @ store r11 into nlr_buf
     str     r13, [r0, #44]          @ store r13=sp into nlr_buf
 
-    ldr     r3, .L2                 @ load addr of nlr_top
+    ldr     r3, nlr_top_addr        @ load addr of nlr_top
     ldr     r2, [r3]                @ load nlr_top
     str     r2, [r0]                @ store nlr_top into nlr_buf
     str     r0, [r3]                @ store nlr_buf into nlr_top (to link list)
@@ -67,8 +67,8 @@ nlr_push:
     movs    r0, #0                  @ return 0, normal return
     bx      lr                      @ return
     .align  2
-.L2:
-    .word   .LANCHOR0
+nlr_top_addr:
+    .word   nlr_top
     .size   nlr_push, .-nlr_push
 
 /**************************************/
@@ -81,14 +81,11 @@ nlr_push:
 #endif
     .type   nlr_pop, %function
 nlr_pop:
-    ldr     r3, .L5                 @ load addr of nlr_top
+    ldr     r3, nlr_top_addr        @ load addr of nlr_top
     ldr     r2, [r3]                @ load nlr_top
     ldr     r2, [r2]                @ load prev nlr_buf
     str     r2, [r3]                @ store prev nlr_buf to nlr_top (to unlink list)
     bx      lr                      @ return
-    .align    2
-.L5:
-    .word    .LANCHOR0
     .size   nlr_pop, .-nlr_pop
 
 /**************************************/
@@ -101,7 +98,7 @@ nlr_pop:
 #endif
     .type   nlr_jump, %function
 nlr_jump:
-    ldr     r3, .L2                 @ load addr of nlr_top
+    ldr     r3, nlr_top_addr        @ load addr of nlr_top
     ldr     r2, [r3]                @ load nlr_top
     cmp     r2, #0                  @ test if nlr_top is NULL
     beq     nlr_jump_fail           @ if nlr_top is NULL, transfer control to nlr_jump_fail
@@ -122,20 +119,6 @@ nlr_jump:
 
     movs    r0, #1                  @ return 1, non-local return
     bx      lr                      @ return
-    .align    2
-.L6:
-    .word    .LANCHOR0
     .size   nlr_jump, .-nlr_jump
 
-/**************************************/
-// local variable nlr_top
-
-    .bss
-    .align  2
-    .set    .LANCHOR0,. + 0
-    .type   nlr_top, %object
-    .size   nlr_top, 4
-nlr_top:
-    .space  4
-
 #endif // (!defined(MICROPY_NLR_SETJMP) || !MICROPY_NLR_SETJMP) && (defined(__thumb2__) || defined(__thumb__) || defined(__arm__))

py/nlrx64.S

@@ -131,15 +131,6 @@ nlr_jump:
     je      _nlr_jump_fail          # transfer control to nlr_jump_fail
 #endif
 
-/**************************************/
-// local variable nlr_top
-
-#if !(defined(__APPLE__) && defined(__MACH__))
-    .bss
-    .local  nlr_top
-#endif
-    .comm   nlr_top,8,8
-
 #else // !defined(__CYGWIN__)
 
 /******************************************************************************/
@@ -210,12 +201,6 @@ nlr_jump:
     movq    %rax, %rcx              # put argument back in first-arg register
     je      nlr_jump_fail           # transfer control to nlr_jump_fail
 
-/**************************************/
-// local variable nlr_top
-
-    .bss
-    .comm   nlr_top,8,8
-
 #endif // !defined(__CYGWIN__)
 
 #endif // defined(__x86_64__) && !MICROPY_NLR_SETJMP

py/nlrx86.S

@@ -121,13 +121,4 @@ nlr_jump:
     .size   nlr_jump, .-nlr_jump
 #endif
 
-/**************************************/
-// local variable nlr_top
-
-    .bss
-#ifndef _WIN32
-    .local  nlr_top
-#endif
-    .comm   nlr_top,4,4
-
 #endif // defined(__i386__) && !MICROPY_NLR_SETJMP

py/nlrxtensa.S

@@ -108,7 +108,4 @@ nlr_jump:
     ret.n
     .size   nlr_jump, .-nlr_jump
 
-    .local  nlr_top
-    .comm   nlr_top,4,4
-
 #endif // defined(__xtensa__)