summaryrefslogtreecommitdiff
path: root/gdb/testsuite/gdb.arch/thumb-prologue.c
blob: c4d371a0f7f7b17459e12b4900663d2100e2d52d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
/* Unwinder test program.

   Copyright 2006-2014 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

void tpcs_frame (void);
void switch_stack_to_same (void);
void switch_stack_to_other (void);

int
main (void)
{
  tpcs_frame ();
  switch_stack_to_same ();
  switch_stack_to_other ();
  return 0;
}

/* Normally Thumb functions use r7 as the frame pointer.  However,
   with the GCC option -mtpcs-frame, they may use fp instead.  Make
   sure that the prologue analyzer can handle this.  */

asm(".text\n"
    "	.align 2\n"
    "	.thumb_func\n"
    "	.code 16\n"
    "tpcs_frame_1:\n"
    "	sub	sp, #16\n"
    "	push	{r7}\n"
    "	add	r7, sp, #20\n"
    "	str	r7, [sp, #8]\n"
    "	mov	r7, pc\n"
    "	str	r7, [sp, #16]\n"
    "	mov	r7, fp\n"
    "	str	r7, [sp, #4]\n"
    "	mov	r7, lr\n"
    "	str	r7, [sp, #12]\n"
    "	add	r7, sp, #16\n"
    "	mov	fp, r7\n"
    "	mov	r7, sl\n"
    "	push	{r7}\n"

    /* We'll set a breakpoint at this call.  We can't hardcode a trap
       instruction; the right instruction to use varies too much.  And
       we can't use a global label, because GDB will think that's the
       start of a new function.  So, this slightly convoluted
       technique.  */
    ".Ltpcs:\n"
    "	nop\n"

    "	pop	{r2}\n"
    "	mov	sl, r2\n"
    "	pop	{r7}\n"
    "	pop	{r1, r2}\n"
    "	mov	fp, r1\n"
    "	mov	sp, r2\n"
    "	bx	lr\n"

    "	.align 2\n"
    "	.type tpcs_offset, %object\n"
    "tpcs_offset:\n"
    "	.word .Ltpcs - tpcs_frame_1\n"

    "	.align 2\n"
    "	.thumb_func\n"
    "	.code 16\n"
    "tpcs_frame:\n"
    "	sub	sp, #16\n"
    "	push	{r7}\n"
    "	add	r7, sp, #20\n"
    "	str	r7, [sp, #8]\n"
    "	mov	r7, pc\n"
    "	str	r7, [sp, #16]\n"
    "	mov	r7, fp\n"
    "	str	r7, [sp, #4]\n"
    "	mov	r7, lr\n"
    "	str	r7, [sp, #12]\n"
    "	add	r7, sp, #16\n"
    "	mov	fp, r7\n"
    "	mov	r7, sl\n"
    "	push	{r7}\n"

    /* Clobber saved regs around the call.  */
    "	mov	r7, #0\n"
    "	mov	lr, r7\n"
    "	bl	tpcs_frame_1\n"

    "	pop	{r2}\n"
    "	mov	sl, r2\n"
    "	pop	{r7}\n"
    "	pop	{r1, r2, r3}\n"
    "	mov	fp, r1\n"
    "	mov	sp, r2\n"
    "	mov	lr, r3\n"
    "	bx	lr\n"
);

asm(".text\n"
    "	.align 2\n"
    "	.thumb_func\n"
    "	.code 16\n"
    "write_sp:\n"
    "	mov	sp, r0\n"
    "	bx	lr\n"

    "	.align 2\n"
    "	.thumb_func\n"
    "	.code 16\n"
    "switch_stack_to_same:\n"
    "	push	{lr}\n"
    "	mov	r0, sp\n"
    "	bl	write_sp\n"
    "	pop	{r1}\n"
    "	bx	r1\n"

    "	.align 2\n"
    "	.thumb_func\n"
    "	.code 16\n"
    "switch_stack_to_other:\n"
    "	push	{lr}\n"
    "	mov	r7, sp\n"
    "	mov	r0, #128\n"
    "	bl	write_sp\n"
    "	mov	sp, r7\n"
    "	pop	{r1}\n"
    "	bx	r1\n");