xpcom/reflect/xptcall/public/xptcall.h@6474c204b198
xpcom/reflect/xptcall/public/xptcall.h
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
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/. */
6 /* Public declarations for xptcall. */
8 #ifndef xptcall_h___
9 #define xptcall_h___
11 #include "nscore.h"
12 #include "nsISupports.h"
13 #include "xpt_struct.h"
14 #include "xptinfo.h"
15 #include "js/Value.h"
17 struct nsXPTCMiniVariant
18 {
19 // No ctors or dtors so that we can use arrays of these on the stack
20 // with no penalty.
21 union
22 {
23 int8_t i8;
24 int16_t i16;
25 int32_t i32;
26 int64_t i64;
27 uint8_t u8;
28 uint16_t u16;
29 uint32_t u32;
30 uint64_t u64;
31 float f;
32 double d;
33 bool b;
34 char c;
35 char16_t wc;
36 void* p;
38 // Types below here are unknown to the assembly implementations, and
39 // therefore _must_ be passed with indirect semantics. We put them in
40 // the union here for type safety, so that we can avoid void* tricks.
41 JS::Value j;
42 } val;
43 };
45 struct nsXPTCVariant : public nsXPTCMiniVariant
46 {
47 // No ctors or dtors so that we can use arrays of these on the stack
48 // with no penalty.
50 // inherits 'val' here
51 void* ptr;
52 nsXPTType type;
53 uint8_t flags;
55 enum
56 {
57 //
58 // Bitflag definitions
59 //
61 // Indicates that ptr (above, and distinct from val.p) is the value that
62 // should be passed on the stack.
63 //
64 // In theory, ptr could point anywhere. But in practice it always points
65 // to &val. So this flag is used to pass 'val' by reference, letting us
66 // avoid the extra allocation we would incur if we were to use val.p.
67 //
68 // Various parts of XPConnect assume that ptr==&val, so we enforce it
69 // explicitly with SetIndirect() and IsIndirect().
70 //
71 // Since ptr always points to &val, the semantics of this flag are kind of
72 // dumb, since the ptr field is unnecessary. But changing them would
73 // require changing dozens of assembly files, so they're likely to stay
74 // the way they are.
75 PTR_IS_DATA = 0x1,
77 // Indicates that the value we hold requires some sort of cleanup (memory
78 // deallocation, interface release, JS::Value unrooting, etc). The precise
79 // cleanup that is performed depends on the 'type' field above.
80 // If the value is an array, this flag specifies whether the elements
81 // within the array require cleanup (we always clean up the array itself,
82 // so this flag would be redundant for that purpose).
83 VAL_NEEDS_CLEANUP = 0x2
84 };
86 void ClearFlags() {flags = 0;}
87 void SetIndirect() {ptr = &val; flags |= PTR_IS_DATA;}
88 void SetValNeedsCleanup() {flags |= VAL_NEEDS_CLEANUP;}
90 bool IsIndirect() const {return 0 != (flags & PTR_IS_DATA);}
91 bool DoesValNeedCleanup() const {return 0 != (flags & VAL_NEEDS_CLEANUP);}
93 // Internal use only. Use IsIndirect() instead.
94 bool IsPtrData() const {return 0 != (flags & PTR_IS_DATA);}
96 void Init(const nsXPTCMiniVariant& mv, const nsXPTType& t, uint8_t f)
97 {
98 type = t;
99 flags = f;
101 if(f & PTR_IS_DATA)
102 {
103 ptr = mv.val.p;
104 val.p = nullptr;
105 }
106 else
107 {
108 ptr = nullptr;
109 val.p = nullptr; // make sure 'val.p' is always initialized
110 switch(t.TagPart()) {
111 case nsXPTType::T_I8: val.i8 = mv.val.i8; break;
112 case nsXPTType::T_I16: val.i16 = mv.val.i16; break;
113 case nsXPTType::T_I32: val.i32 = mv.val.i32; break;
114 case nsXPTType::T_I64: val.i64 = mv.val.i64; break;
115 case nsXPTType::T_U8: val.u8 = mv.val.u8; break;
116 case nsXPTType::T_U16: val.u16 = mv.val.u16; break;
117 case nsXPTType::T_U32: val.u32 = mv.val.u32; break;
118 case nsXPTType::T_U64: val.u64 = mv.val.u64; break;
119 case nsXPTType::T_FLOAT: val.f = mv.val.f; break;
120 case nsXPTType::T_DOUBLE: val.d = mv.val.d; break;
121 case nsXPTType::T_BOOL: val.b = mv.val.b; break;
122 case nsXPTType::T_CHAR: val.c = mv.val.c; break;
123 case nsXPTType::T_WCHAR: val.wc = mv.val.wc; break;
124 case nsXPTType::T_VOID: /* fall through */
125 case nsXPTType::T_IID: /* fall through */
126 case nsXPTType::T_DOMSTRING: /* fall through */
127 case nsXPTType::T_CHAR_STR: /* fall through */
128 case nsXPTType::T_WCHAR_STR: /* fall through */
129 case nsXPTType::T_INTERFACE: /* fall through */
130 case nsXPTType::T_INTERFACE_IS: /* fall through */
131 case nsXPTType::T_ARRAY: /* fall through */
132 case nsXPTType::T_PSTRING_SIZE_IS: /* fall through */
133 case nsXPTType::T_PWSTRING_SIZE_IS: /* fall through */
134 case nsXPTType::T_UTF8STRING: /* fall through */
135 case nsXPTType::T_CSTRING: /* fall through */
136 default: val.p = mv.val.p; break;
137 }
138 }
139 }
140 };
142 class nsIXPTCProxy : public nsISupports
143 {
144 public:
145 NS_IMETHOD CallMethod(uint16_t aMethodIndex,
146 const XPTMethodDescriptor *aInfo,
147 nsXPTCMiniVariant *aParams) = 0;
148 };
150 /**
151 * This is a typedef to avoid confusion between the canonical
152 * nsISupports* that provides object identity and an interface pointer
153 * for inheriting interfaces that aren't known at compile-time.
154 */
155 typedef nsISupports nsISomeInterface;
157 /**
158 * Get a proxy object to implement the specified interface.
159 *
160 * @param aIID The IID of the interface to implement.
161 * @param aOuter An object to receive method calls from the proxy object.
162 * The stub forwards QueryInterface/AddRef/Release to the
163 * outer object. The proxy object does not hold a reference to
164 * the outer object; it is the caller's responsibility to
165 * ensure that this pointer remains valid until the stub has
166 * been destroyed.
167 * @param aStub Out parameter for the new proxy object. The object is
168 * not addrefed. The object never destroys itself. It must be
169 * explicitly destroyed by calling
170 * NS_DestroyXPTCallStub when it is no longer needed.
171 */
172 XPCOM_API(nsresult)
173 NS_GetXPTCallStub(REFNSIID aIID, nsIXPTCProxy* aOuter,
174 nsISomeInterface* *aStub);
176 /**
177 * Destroys an XPTCall stub previously created with NS_GetXPTCallStub.
178 */
179 XPCOM_API(void)
180 NS_DestroyXPTCallStub(nsISomeInterface* aStub);
182 XPCOM_API(nsresult)
183 NS_InvokeByIndex(nsISupports* that, uint32_t methodIndex,
184 uint32_t paramCount, nsXPTCVariant* params);
186 #endif /* xptcall_h___ */
