Mercurial > pub > dyncall > dyncall
view dyncallback/dyncall_callback_arm32_arm_apple.s @ 97:d0787f3b81fb
- internal linkage for some helper functions
- corrected and added some comments for clarification
author | cslag |
---|---|
date | Sat, 04 Jun 2016 19:35:58 +0200 |
parents | 00310bf92924 |
children | 91db39538e78 |
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/* Package: dyncall Library: dyncallback File: dyncallback/dyncall_callback_arm32_arm_apple.s Description: Callback Thunk - Implementation for ARM32 (ARM mode) for Apple's as License: Copyright (c) 2007-2011 Daniel Adler <dadler@uni-goettingen.de>, Tassilo Philipp <tphilipp@potion-studios.com> Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ .text .code 32 /* ARM mode */ .globl _dcCallbackThunkEntry .align 4 /* sizes */ .set DCThunk_size , 8 .set DCArgs_size , 24 .set DCCallback_size, 20 .set DCValue_size , 8 /* struct DCCallback offsets and size */ .set CTX_thunk , 0 .set CTX_handler , 12 .set CTX_userdata , 16 /* Called by thunk - thunk stores pointer to DCCallback in r12 */ _dcCallbackThunkEntry: /* Prolog. This function never needs to spill inside its prolog, so just store the permanent registers. */ stmdb r13, {r4-r11, r13, r14} /* Permanent registers and stack pointer, etc... -> save area on stack (except counter). */ mov r11, r13 /* Set frame pointer. */ sub r13, r13, #40 /* Adjust stack pointer. */ /* Grab arguments. */ mov r4, #0 stmdb r13!, {r0-r4, r11} /* Spill first 4 args to DCArgs, along with reg_count and (stack) pointer to remaining args. */ /* Prepare callback handler call. */ mov r0, r12 /* Parameter 0 (r0) = DCCallback pointer (r12, pointer to thunk). */ mov r1, r13 /* Parameter 1 (r1) = DCArgs pointer (r13, stack pointer). */ sub r13, r13, #DCValue_size /* Make room for return value. */ mov r2, r13 /* Parameter 2 (r2) = results pointer. */ ldr r3, [r12, #CTX_userdata] /* Parameter 3 (r3) = userdata pointer. */ /* Call. */ ldr r4, [r12, #CTX_handler] /* Load callback handler pointer into r4. */ mov r14, r15 /* Branch return address(r15) -> link register (r14) -- r15 always points to address of current + 2 instructions (= Epilog code). */ bx r4 /* Call. */ /* Return value. */ ldmia r13, {r0, r1} /* Load return value in r0 and r1. */ /* Epilog. */ ldmdb r11, {r4-r11, r13, r15} /* Restore permanent registers (restore stack ptr and program counter).@@@db not needed since we rewrite r13? */