1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/xpcom/reflect/xptcall/public/xptcall.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,186 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/* Public declarations for xptcall. */
1.10 +
1.11 +#ifndef xptcall_h___
1.12 +#define xptcall_h___
1.13 +
1.14 +#include "nscore.h"
1.15 +#include "nsISupports.h"
1.16 +#include "xpt_struct.h"
1.17 +#include "xptinfo.h"
1.18 +#include "js/Value.h"
1.19 +
1.20 +struct nsXPTCMiniVariant
1.21 +{
1.22 +// No ctors or dtors so that we can use arrays of these on the stack
1.23 +// with no penalty.
1.24 + union
1.25 + {
1.26 + int8_t i8;
1.27 + int16_t i16;
1.28 + int32_t i32;
1.29 + int64_t i64;
1.30 + uint8_t u8;
1.31 + uint16_t u16;
1.32 + uint32_t u32;
1.33 + uint64_t u64;
1.34 + float f;
1.35 + double d;
1.36 + bool b;
1.37 + char c;
1.38 + char16_t wc;
1.39 + void* p;
1.40 +
1.41 + // Types below here are unknown to the assembly implementations, and
1.42 + // therefore _must_ be passed with indirect semantics. We put them in
1.43 + // the union here for type safety, so that we can avoid void* tricks.
1.44 + JS::Value j;
1.45 + } val;
1.46 +};
1.47 +
1.48 +struct nsXPTCVariant : public nsXPTCMiniVariant
1.49 +{
1.50 +// No ctors or dtors so that we can use arrays of these on the stack
1.51 +// with no penalty.
1.52 +
1.53 + // inherits 'val' here
1.54 + void* ptr;
1.55 + nsXPTType type;
1.56 + uint8_t flags;
1.57 +
1.58 + enum
1.59 + {
1.60 + //
1.61 + // Bitflag definitions
1.62 + //
1.63 +
1.64 + // Indicates that ptr (above, and distinct from val.p) is the value that
1.65 + // should be passed on the stack.
1.66 + //
1.67 + // In theory, ptr could point anywhere. But in practice it always points
1.68 + // to &val. So this flag is used to pass 'val' by reference, letting us
1.69 + // avoid the extra allocation we would incur if we were to use val.p.
1.70 + //
1.71 + // Various parts of XPConnect assume that ptr==&val, so we enforce it
1.72 + // explicitly with SetIndirect() and IsIndirect().
1.73 + //
1.74 + // Since ptr always points to &val, the semantics of this flag are kind of
1.75 + // dumb, since the ptr field is unnecessary. But changing them would
1.76 + // require changing dozens of assembly files, so they're likely to stay
1.77 + // the way they are.
1.78 + PTR_IS_DATA = 0x1,
1.79 +
1.80 + // Indicates that the value we hold requires some sort of cleanup (memory
1.81 + // deallocation, interface release, JS::Value unrooting, etc). The precise
1.82 + // cleanup that is performed depends on the 'type' field above.
1.83 + // If the value is an array, this flag specifies whether the elements
1.84 + // within the array require cleanup (we always clean up the array itself,
1.85 + // so this flag would be redundant for that purpose).
1.86 + VAL_NEEDS_CLEANUP = 0x2
1.87 + };
1.88 +
1.89 + void ClearFlags() {flags = 0;}
1.90 + void SetIndirect() {ptr = &val; flags |= PTR_IS_DATA;}
1.91 + void SetValNeedsCleanup() {flags |= VAL_NEEDS_CLEANUP;}
1.92 +
1.93 + bool IsIndirect() const {return 0 != (flags & PTR_IS_DATA);}
1.94 + bool DoesValNeedCleanup() const {return 0 != (flags & VAL_NEEDS_CLEANUP);}
1.95 +
1.96 + // Internal use only. Use IsIndirect() instead.
1.97 + bool IsPtrData() const {return 0 != (flags & PTR_IS_DATA);}
1.98 +
1.99 + void Init(const nsXPTCMiniVariant& mv, const nsXPTType& t, uint8_t f)
1.100 + {
1.101 + type = t;
1.102 + flags = f;
1.103 +
1.104 + if(f & PTR_IS_DATA)
1.105 + {
1.106 + ptr = mv.val.p;
1.107 + val.p = nullptr;
1.108 + }
1.109 + else
1.110 + {
1.111 + ptr = nullptr;
1.112 + val.p = nullptr; // make sure 'val.p' is always initialized
1.113 + switch(t.TagPart()) {
1.114 + case nsXPTType::T_I8: val.i8 = mv.val.i8; break;
1.115 + case nsXPTType::T_I16: val.i16 = mv.val.i16; break;
1.116 + case nsXPTType::T_I32: val.i32 = mv.val.i32; break;
1.117 + case nsXPTType::T_I64: val.i64 = mv.val.i64; break;
1.118 + case nsXPTType::T_U8: val.u8 = mv.val.u8; break;
1.119 + case nsXPTType::T_U16: val.u16 = mv.val.u16; break;
1.120 + case nsXPTType::T_U32: val.u32 = mv.val.u32; break;
1.121 + case nsXPTType::T_U64: val.u64 = mv.val.u64; break;
1.122 + case nsXPTType::T_FLOAT: val.f = mv.val.f; break;
1.123 + case nsXPTType::T_DOUBLE: val.d = mv.val.d; break;
1.124 + case nsXPTType::T_BOOL: val.b = mv.val.b; break;
1.125 + case nsXPTType::T_CHAR: val.c = mv.val.c; break;
1.126 + case nsXPTType::T_WCHAR: val.wc = mv.val.wc; break;
1.127 + case nsXPTType::T_VOID: /* fall through */
1.128 + case nsXPTType::T_IID: /* fall through */
1.129 + case nsXPTType::T_DOMSTRING: /* fall through */
1.130 + case nsXPTType::T_CHAR_STR: /* fall through */
1.131 + case nsXPTType::T_WCHAR_STR: /* fall through */
1.132 + case nsXPTType::T_INTERFACE: /* fall through */
1.133 + case nsXPTType::T_INTERFACE_IS: /* fall through */
1.134 + case nsXPTType::T_ARRAY: /* fall through */
1.135 + case nsXPTType::T_PSTRING_SIZE_IS: /* fall through */
1.136 + case nsXPTType::T_PWSTRING_SIZE_IS: /* fall through */
1.137 + case nsXPTType::T_UTF8STRING: /* fall through */
1.138 + case nsXPTType::T_CSTRING: /* fall through */
1.139 + default: val.p = mv.val.p; break;
1.140 + }
1.141 + }
1.142 + }
1.143 +};
1.144 +
1.145 +class nsIXPTCProxy : public nsISupports
1.146 +{
1.147 +public:
1.148 + NS_IMETHOD CallMethod(uint16_t aMethodIndex,
1.149 + const XPTMethodDescriptor *aInfo,
1.150 + nsXPTCMiniVariant *aParams) = 0;
1.151 +};
1.152 +
1.153 +/**
1.154 + * This is a typedef to avoid confusion between the canonical
1.155 + * nsISupports* that provides object identity and an interface pointer
1.156 + * for inheriting interfaces that aren't known at compile-time.
1.157 + */
1.158 +typedef nsISupports nsISomeInterface;
1.159 +
1.160 +/**
1.161 + * Get a proxy object to implement the specified interface.
1.162 + *
1.163 + * @param aIID The IID of the interface to implement.
1.164 + * @param aOuter An object to receive method calls from the proxy object.
1.165 + * The stub forwards QueryInterface/AddRef/Release to the
1.166 + * outer object. The proxy object does not hold a reference to
1.167 + * the outer object; it is the caller's responsibility to
1.168 + * ensure that this pointer remains valid until the stub has
1.169 + * been destroyed.
1.170 + * @param aStub Out parameter for the new proxy object. The object is
1.171 + * not addrefed. The object never destroys itself. It must be
1.172 + * explicitly destroyed by calling
1.173 + * NS_DestroyXPTCallStub when it is no longer needed.
1.174 + */
1.175 +XPCOM_API(nsresult)
1.176 +NS_GetXPTCallStub(REFNSIID aIID, nsIXPTCProxy* aOuter,
1.177 + nsISomeInterface* *aStub);
1.178 +
1.179 +/**
1.180 + * Destroys an XPTCall stub previously created with NS_GetXPTCallStub.
1.181 + */
1.182 +XPCOM_API(void)
1.183 +NS_DestroyXPTCallStub(nsISomeInterface* aStub);
1.184 +
1.185 +XPCOM_API(nsresult)
1.186 +NS_InvokeByIndex(nsISupports* that, uint32_t methodIndex,
1.187 + uint32_t paramCount, nsXPTCVariant* params);
1.188 +
1.189 +#endif /* xptcall_h___ */
