1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5
6 /* Platform specific code to invoke XPCOM methods on native objects */
7
8 #include "xptcprivate.h"
9 #include "xptc_gcc_x86_unix.h"
10
11 extern "C" {
12 static void ATTRIBUTE_USED __attribute__ ((regparm(3)))
invoke_copy_to_stack(uint32_t paramCount,nsXPTCVariant * s,uint32_t * d)13 invoke_copy_to_stack(uint32_t paramCount, nsXPTCVariant* s, uint32_t* d)
14 {
15 for(uint32_t i = paramCount; i >0; i--, d++, s++)
16 {
17 if(s->IsPtrData())
18 {
19 *((void**)d) = s->ptr;
20 continue;
21 }
22
23 switch(s->type)
24 {
25 case nsXPTType::T_I64 : *((int64_t*) d) = s->val.i64; d++; break;
26 case nsXPTType::T_U64 : *((uint64_t*)d) = s->val.u64; d++; break;
27 case nsXPTType::T_DOUBLE : *((double*) d) = s->val.d; d++; break;
28 default : *((void**)d) = s->val.p; break;
29 }
30 }
31 }
32 } // extern "C"
33
34 /*
35 EXPORT_XPCOM_API(nsresult)
36 NS_InvokeByIndex(nsISupports* that, uint32_t methodIndex,
37 uint32_t paramCount, nsXPTCVariant* params);
38
39 Each param takes at most two 4-byte words.
40 It doesn't matter if we push too many words, and calculating the exact
41 amount takes time.
42
43 that = ebp + 0x08
44 methodIndex = ebp + 0x0c
45 paramCount = ebp + 0x10
46 params = ebp + 0x14
47
48 */
49
50 __asm__ (
51 ".text\n\t"
52 /* alignment here seems unimportant here; this was 16, now it's 2 which
53 is what xptcstubs uses. */
54 ".align 2\n\t"
55 ".globl " SYMBOL_UNDERSCORE "NS_InvokeByIndex\n\t"
56 #ifndef XP_MACOSX
57 ".type " SYMBOL_UNDERSCORE "NS_InvokeByIndex,@function\n"
58 #endif
59 SYMBOL_UNDERSCORE "NS_InvokeByIndex:\n\t"
60 "pushl %ebp\n\t"
61 "movl %esp, %ebp\n\t"
62 "movl 0x10(%ebp), %eax\n\t"
63 "leal 0(,%eax,8),%edx\n\t"
64
65 /* set up call frame for method. */
66 "subl %edx, %esp\n\t" /* make room for params. */
67 /* Align to maximum x86 data size: 128 bits == 16 bytes == XMM register size.
68 * This is to avoid protection faults where SSE+ alignment of stack pointer
69 * is assumed and required, e.g. by GCC4's -ftree-vectorize option.
70 */
71 "andl $0xfffffff0, %esp\n\t" /* drop(?) stack ptr to 128-bit align */
72 /* $esp should be aligned to a 16-byte boundary here (note we include an
73 * additional 4 bytes in a later push instruction). This will ensure $ebp
74 * in the function called below is aligned to a 0x8 boundary. SSE instructions
75 * like movapd/movdqa expect memory operand to be aligned on a 16-byte
76 * boundary. The GCC compiler will generate the memory operand using $ebp
77 * with an 8-byte offset.
78 */
79 "subl $0xc, %esp\n\t" /* lower again; push/call below will re-align */
80 "movl %esp, %ecx\n\t" /* ecx = d */
81 "movl 8(%ebp), %edx\n\t" /* edx = this */
82 "pushl %edx\n\t" /* push this. esp % 16 == 0 */
83
84 "movl 0x14(%ebp), %edx\n\t"
85 "call " SYMBOL_UNDERSCORE "invoke_copy_to_stack\n\t"
86 "movl 0x08(%ebp), %ecx\n\t" /* 'that' */
87 "movl (%ecx), %edx\n\t"
88 "movl 0x0c(%ebp), %eax\n\t" /* function index */
89 "leal (%edx,%eax,4), %edx\n\t"
90 "call *(%edx)\n\t"
91 "movl %ebp, %esp\n\t"
92 "popl %ebp\n\t"
93 "ret\n"
94 #ifndef XP_MACOSX
95 ".size " SYMBOL_UNDERSCORE "NS_InvokeByIndex, . -" SYMBOL_UNDERSCORE "NS_InvokeByIndex\n\t"
96 #endif
97 );
98