/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ /* Public declarations for xptcall. */ #ifndef xptcall_h___ #define xptcall_h___ #include "nscore.h" #include "nsISupports.h" #include "xpt_struct.h" #include "xptinfo.h" #include "js/Value.h" #include "mozilla/MemoryReporting.h" struct nsXPTCMiniVariant { // No ctors or dtors so that we can use arrays of these on the stack // with no penalty. union { int8_t i8; int16_t i16; int32_t i32; int64_t i64; uint8_t u8; uint16_t u16; uint32_t u32; uint64_t u64; float f; double d; bool b; char c; char16_t wc; void* p; // Types below here are unknown to the assembly implementations, and // therefore _must_ be passed with indirect semantics. We put them in // the union here for type safety, so that we can avoid void* tricks. JS::Value j; } val; }; struct nsXPTCVariant : public nsXPTCMiniVariant { // No ctors or dtors so that we can use arrays of these on the stack // with no penalty. // inherits 'val' here void* ptr; nsXPTType type; uint8_t flags; enum { // // Bitflag definitions // // Indicates that ptr (above, and distinct from val.p) is the value that // should be passed on the stack. // // In theory, ptr could point anywhere. But in practice it always points // to &val. So this flag is used to pass 'val' by reference, letting us // avoid the extra allocation we would incur if we were to use val.p. // // Various parts of XPConnect assume that ptr==&val, so we enforce it // explicitly with SetIndirect() and IsIndirect(). // // Since ptr always points to &val, the semantics of this flag are kind of // dumb, since the ptr field is unnecessary. But changing them would // require changing dozens of assembly files, so they're likely to stay // the way they are. PTR_IS_DATA = 0x1, // Indicates that the value we hold requires some sort of cleanup (memory // deallocation, interface release, JS::Value unrooting, etc). The precise // cleanup that is performed depends on the 'type' field above. // If the value is an array, this flag specifies whether the elements // within the array require cleanup (we always clean up the array itself, // so this flag would be redundant for that purpose). VAL_NEEDS_CLEANUP = 0x2 }; void ClearFlags() {flags = 0;} void SetIndirect() {ptr = &val; flags |= PTR_IS_DATA;} void SetValNeedsCleanup() {flags |= VAL_NEEDS_CLEANUP;} bool IsIndirect() const {return 0 != (flags & PTR_IS_DATA);} bool DoesValNeedCleanup() const {return 0 != (flags & VAL_NEEDS_CLEANUP);} // Internal use only. Use IsIndirect() instead. bool IsPtrData() const {return 0 != (flags & PTR_IS_DATA);} void Init(const nsXPTCMiniVariant& mv, const nsXPTType& t, uint8_t f) { type = t; flags = f; if(f & PTR_IS_DATA) { ptr = mv.val.p; val.p = nullptr; } else { ptr = nullptr; val.p = nullptr; // make sure 'val.p' is always initialized switch(t.TagPart()) { case nsXPTType::T_I8: val.i8 = mv.val.i8; break; case nsXPTType::T_I16: val.i16 = mv.val.i16; break; case nsXPTType::T_I32: val.i32 = mv.val.i32; break; case nsXPTType::T_I64: val.i64 = mv.val.i64; break; case nsXPTType::T_U8: val.u8 = mv.val.u8; break; case nsXPTType::T_U16: val.u16 = mv.val.u16; break; case nsXPTType::T_U32: val.u32 = mv.val.u32; break; case nsXPTType::T_U64: val.u64 = mv.val.u64; break; case nsXPTType::T_FLOAT: val.f = mv.val.f; break; case nsXPTType::T_DOUBLE: val.d = mv.val.d; break; case nsXPTType::T_BOOL: val.b = mv.val.b; break; case nsXPTType::T_CHAR: val.c = mv.val.c; break; case nsXPTType::T_WCHAR: val.wc = mv.val.wc; break; case nsXPTType::T_VOID: /* fall through */ case nsXPTType::T_IID: /* fall through */ case nsXPTType::T_DOMSTRING: /* fall through */ case nsXPTType::T_CHAR_STR: /* fall through */ case nsXPTType::T_WCHAR_STR: /* fall through */ case nsXPTType::T_INTERFACE: /* fall through */ case nsXPTType::T_INTERFACE_IS: /* fall through */ case nsXPTType::T_ARRAY: /* fall through */ case nsXPTType::T_PSTRING_SIZE_IS: /* fall through */ case nsXPTType::T_PWSTRING_SIZE_IS: /* fall through */ case nsXPTType::T_UTF8STRING: /* fall through */ case nsXPTType::T_CSTRING: /* fall through */ default: val.p = mv.val.p; break; } } } }; class nsIXPTCProxy : public nsISupports { public: NS_IMETHOD CallMethod(uint16_t aMethodIndex, const XPTMethodDescriptor *aInfo, nsXPTCMiniVariant *aParams) = 0; }; /** * This is a typedef to avoid confusion between the canonical * nsISupports* that provides object identity and an interface pointer * for inheriting interfaces that aren't known at compile-time. */ typedef nsISupports nsISomeInterface; /** * Get a proxy object to implement the specified interface. * * @param aIID The IID of the interface to implement. * @param aOuter An object to receive method calls from the proxy object. * The stub forwards QueryInterface/AddRef/Release to the * outer object. The proxy object does not hold a reference to * the outer object; it is the caller's responsibility to * ensure that this pointer remains valid until the stub has * been destroyed. * @param aStub Out parameter for the new proxy object. The object is * not addrefed. The object never destroys itself. It must be * explicitly destroyed by calling * NS_DestroyXPTCallStub when it is no longer needed. */ XPCOM_API(nsresult) NS_GetXPTCallStub(REFNSIID aIID, nsIXPTCProxy* aOuter, nsISomeInterface* *aStub); /** * Destroys an XPTCall stub previously created with NS_GetXPTCallStub. */ XPCOM_API(void) NS_DestroyXPTCallStub(nsISomeInterface* aStub); /** * Measures the size of an XPTCall stub previously created with NS_GetXPTCallStub. */ XPCOM_API(size_t) NS_SizeOfIncludingThisXPTCallStub(const nsISomeInterface* aStub, mozilla::MallocSizeOf aMallocSizeOf); // this is extern "C" because on some platforms it is implemented in assembly extern "C" nsresult NS_InvokeByIndex(nsISupports* that, uint32_t methodIndex, uint32_t paramCount, nsXPTCVariant* params); #endif /* xptcall_h___ */