1 | // Copyright (C) 2022 The Qt Company Ltd. |
2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
3 | |
4 | #ifndef QV4STACKLIMITS_P_H |
5 | #define QV4STACKLIMITS_P_H |
6 | |
7 | // |
8 | // W A R N I N G |
9 | // ------------- |
10 | // |
11 | // This file is not part of the Qt API. It exists purely as an |
12 | // implementation detail. This header file may change from version to |
13 | // version without notice, or even be removed. |
14 | // |
15 | // We mean it. |
16 | // |
17 | |
18 | #include <private/qtqmlglobal_p.h> |
19 | |
20 | #ifndef Q_STACK_GROWTH_DIRECTION |
21 | # ifdef Q_PROCESSOR_HPPA |
22 | # define Q_STACK_GROWTH_DIRECTION (1) |
23 | # else |
24 | # define Q_STACK_GROWTH_DIRECTION (-1) |
25 | # endif |
26 | #endif |
27 | |
28 | QT_BEGIN_NAMESPACE |
29 | |
30 | namespace QV4 { |
31 | |
32 | // Note: This does not return a completely accurate stack pointer. |
33 | // Depending on whether this function is inlined or not, we may get the address of |
34 | // this function's stack frame or the caller's stack frame. |
35 | // Always use a safety margin when determining stack limits. |
36 | inline const void *currentStackPointer() |
37 | { |
38 | // TODO: How often do we actually need the assembler mess below? Is that worth it? |
39 | |
40 | void *stackPointer; |
41 | #if defined(Q_CC_GNU) || __has_builtin(__builtin_frame_address) |
42 | stackPointer = __builtin_frame_address(0); |
43 | #elif defined(Q_CC_MSVC) |
44 | stackPointer = &stackPointer; |
45 | #elif defined(Q_PROCESSOR_X86_64) |
46 | __asm__ __volatile__("movq %%rsp, %0" : "=r" (stackPointer) : :); |
47 | #elif defined(Q_PROCESSOR_X86) |
48 | __asm__ __volatile__("movl %%esp, %0" : "=r" (stackPointer) : :); |
49 | #elif defined(Q_PROCESSOR_ARM_64) && defined(__ILP32__) |
50 | quint64 stackPointerRegister = 0; |
51 | __asm__ __volatile__("mov %0, sp" : "=r" (stackPointerRegister) : :); |
52 | stackPointer = reinterpret_cast<void *>(stackPointerRegister); |
53 | #elif defined(Q_PROCESSOR_ARM_64) || defined(Q_PROCESSOR_ARM_32) |
54 | __asm__ __volatile__("mov %0, sp" : "=r" (stackPointer) : :); |
55 | #else |
56 | stackPointer = &stackPointer; |
57 | #endif |
58 | return stackPointer; |
59 | } |
60 | |
61 | struct StackProperties |
62 | { |
63 | const void *base = nullptr; |
64 | const void *softLimit = nullptr; |
65 | const void *hardLimit = nullptr; |
66 | }; |
67 | |
68 | StackProperties stackProperties(); |
69 | |
70 | } // namespace QV4 |
71 | |
72 | QT_END_NAMESPACE |
73 | |
74 | #endif // QV4STACKLIMITS_P_H |
75 | |