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Diffstat (limited to 'xpcom/reflect/xptcall/xptcall.h')
| -rw-r--r-- | xpcom/reflect/xptcall/xptcall.h | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/xpcom/reflect/xptcall/xptcall.h b/xpcom/reflect/xptcall/xptcall.h new file mode 100644 index 000000000..1f2367b5d --- /dev/null +++ b/xpcom/reflect/xptcall/xptcall.h @@ -0,0 +1,193 @@ +/* -*- 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); + +XPCOM_API(nsresult) +NS_InvokeByIndex(nsISupports* that, uint32_t methodIndex, + uint32_t paramCount, nsXPTCVariant* params); + +#endif /* xptcall_h___ */ |