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Diffstat (limited to 'portaudio/src/hostapi/asio/iasiothiscallresolver.cpp')
| -rw-r--r-- | portaudio/src/hostapi/asio/iasiothiscallresolver.cpp | 563 |
1 files changed, 563 insertions, 0 deletions
diff --git a/portaudio/src/hostapi/asio/iasiothiscallresolver.cpp b/portaudio/src/hostapi/asio/iasiothiscallresolver.cpp new file mode 100644 index 0000000..8dfefbd --- /dev/null +++ b/portaudio/src/hostapi/asio/iasiothiscallresolver.cpp @@ -0,0 +1,563 @@ +/* + IASIOThiscallResolver.cpp see the comments in iasiothiscallresolver.h for + the top level description - this comment describes the technical details of + the implementation. + + The latest version of this file is available from: + http://www.audiomulch.com/~rossb/code/calliasio + + please email comments to Ross Bencina <rossb@audiomulch.com> + + BACKGROUND + + The IASIO interface declared in the Steinberg ASIO 2 SDK declares + functions with no explicit calling convention. This causes MSVC++ to default + to using the thiscall convention, which is a proprietary convention not + implemented by some non-microsoft compilers - notably borland BCC, + C++Builder, and gcc. MSVC++ is the defacto standard compiler used by + Steinberg. As a result of this situation, the ASIO sdk will compile with + any compiler, however attempting to execute the compiled code will cause a + crash due to different default calling conventions on non-Microsoft + compilers. + + IASIOThiscallResolver solves the problem by providing an adapter class that + delegates to the IASIO interface using the correct calling convention + (thiscall). Due to the lack of support for thiscall in the Borland and GCC + compilers, the calls have been implemented in assembly language. + + A number of macros are defined for thiscall function calls with different + numbers of parameters, with and without return values - it may be possible + to modify the format of these macros to make them work with other inline + assemblers. + + + THISCALL DEFINITION + + A number of definitions of the thiscall calling convention are floating + around the internet. The following definition has been validated against + output from the MSVC++ compiler: + + For non-vararg functions, thiscall works as follows: the object (this) + pointer is passed in ECX. All arguments are passed on the stack in + right to left order. The return value is placed in EAX. The callee + clears the passed arguments from the stack. + + + FINDING FUNCTION POINTERS FROM AN IASIO POINTER + + The first field of a COM object is a pointer to its vtble. Thus a pointer + to an object implementing the IASIO interface also points to a pointer to + that object's vtbl. The vtble is a table of function pointers for all of + the virtual functions exposed by the implemented interfaces. + + If we consider a variable declared as a pointer to IASO: + + IASIO *theAsioDriver + + theAsioDriver points to: + + object implementing IASIO + { + IASIOvtbl *vtbl + other data + } + + in other words, theAsioDriver points to a pointer to an IASIOvtbl + + vtbl points to a table of function pointers: + + IASIOvtbl ( interface IASIO : public IUnknown ) + { + (IUnknown functions) + 0 virtual HRESULT STDMETHODCALLTYPE (*QueryInterface)(REFIID riid, void **ppv) = 0; + 4 virtual ULONG STDMETHODCALLTYPE (*AddRef)() = 0; + 8 virtual ULONG STDMETHODCALLTYPE (*Release)() = 0; + + (IASIO functions) + 12 virtual ASIOBool (*init)(void *sysHandle) = 0; + 16 virtual void (*getDriverName)(char *name) = 0; + 20 virtual long (*getDriverVersion)() = 0; + 24 virtual void (*getErrorMessage)(char *string) = 0; + 28 virtual ASIOError (*start)() = 0; + 32 virtual ASIOError (*stop)() = 0; + 36 virtual ASIOError (*getChannels)(long *numInputChannels, long *numOutputChannels) = 0; + 40 virtual ASIOError (*getLatencies)(long *inputLatency, long *outputLatency) = 0; + 44 virtual ASIOError (*getBufferSize)(long *minSize, long *maxSize, + long *preferredSize, long *granularity) = 0; + 48 virtual ASIOError (*canSampleRate)(ASIOSampleRate sampleRate) = 0; + 52 virtual ASIOError (*getSampleRate)(ASIOSampleRate *sampleRate) = 0; + 56 virtual ASIOError (*setSampleRate)(ASIOSampleRate sampleRate) = 0; + 60 virtual ASIOError (*getClockSources)(ASIOClockSource *clocks, long *numSources) = 0; + 64 virtual ASIOError (*setClockSource)(long reference) = 0; + 68 virtual ASIOError (*getSamplePosition)(ASIOSamples *sPos, ASIOTimeStamp *tStamp) = 0; + 72 virtual ASIOError (*getChannelInfo)(ASIOChannelInfo *info) = 0; + 76 virtual ASIOError (*createBuffers)(ASIOBufferInfo *bufferInfos, long numChannels, + long bufferSize, ASIOCallbacks *callbacks) = 0; + 80 virtual ASIOError (*disposeBuffers)() = 0; + 84 virtual ASIOError (*controlPanel)() = 0; + 88 virtual ASIOError (*future)(long selector,void *opt) = 0; + 92 virtual ASIOError (*outputReady)() = 0; + }; + + The numbers in the left column show the byte offset of each function ptr + from the beginning of the vtbl. These numbers are used in the code below + to select different functions. + + In order to find the address of a particular function, theAsioDriver + must first be dereferenced to find the value of the vtbl pointer: + + mov eax, theAsioDriver + mov edx, [theAsioDriver] // edx now points to vtbl[0] + + Then an offset must be added to the vtbl pointer to select a + particular function, for example vtbl+44 points to the slot containing + a pointer to the getBufferSize function. + + Finally vtbl+x must be dereferenced to obtain the value of the function + pointer stored in that address: + + call [edx+44] // call the function pointed to by + // the value in the getBufferSize field of the vtbl + + + SEE ALSO + + Martin Fay's OpenASIO DLL at http://www.martinfay.com solves the same + problem by providing a new COM interface which wraps IASIO with an + interface that uses portable calling conventions. OpenASIO must be compiled + with MSVC, and requires that you ship the OpenASIO DLL with your + application. + + + ACKNOWLEDGEMENTS + + Ross Bencina: worked out the thiscall details above, wrote the original + Borland asm macros, and a patch for asio.cpp (which is no longer needed). + Thanks to Martin Fay for introducing me to the issues discussed here, + and to Rene G. Ceballos for assisting with asm dumps from MSVC++. + + Antti Silvast: converted the original calliasio to work with gcc and NASM + by implementing the asm code in a separate file. + + Fraser Adams: modified the original calliasio containing the Borland inline + asm to add inline asm for gcc i.e. Intel syntax for Borland and AT&T syntax + for gcc. This seems a neater approach for gcc than to have a separate .asm + file and it means that we only need one version of the thiscall patch. + + Fraser Adams: rewrote the original calliasio patch in the form of the + IASIOThiscallResolver class in order to avoid modifications to files from + the Steinberg SDK, which may have had potential licence issues. + + Andrew Baldwin: contributed fixes for compatibility problems with more + recent versions of the gcc assembler. +*/ + + +// We only need IASIOThiscallResolver at all if we are on Win32. For other +// platforms we simply bypass the IASIOThiscallResolver definition to allow us +// to be safely #include'd whatever the platform to keep client code portable +#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) + + +// If microsoft compiler we can call IASIO directly so IASIOThiscallResolver +// is not used. +#if !defined(_MSC_VER) + + +#include <new> +#include <assert.h> + +// We have a mechanism in iasiothiscallresolver.h to ensure that asio.h is +// #include'd before it in client code, we do NOT want to do this test here. +#define iasiothiscallresolver_sourcefile 1 +#include "iasiothiscallresolver.h" +#undef iasiothiscallresolver_sourcefile + +// iasiothiscallresolver.h redefines ASIOInit for clients, but we don't want +// this macro defined in this translation unit. +#undef ASIOInit + + +// theAsioDriver is a global pointer to the current IASIO instance which the +// ASIO SDK uses to perform all actions on the IASIO interface. We substitute +// our own forwarding interface into this pointer. +extern IASIO* theAsioDriver; + + +// The following macros define the inline assembler for BORLAND first then gcc + +#if defined(__BCPLUSPLUS__) || defined(__BORLANDC__) + + +#define CALL_THISCALL_0( resultName, thisPtr, funcOffset )\ + void *this_ = (thisPtr); \ + __asm { \ + mov ecx, this_ ; \ + mov eax, [ecx] ; \ + call [eax+funcOffset] ; \ + mov resultName, eax ; \ + } + + +#define CALL_VOID_THISCALL_1( thisPtr, funcOffset, param1 )\ + void *this_ = (thisPtr); \ + __asm { \ + mov eax, param1 ; \ + push eax ; \ + mov ecx, this_ ; \ + mov eax, [ecx] ; \ + call [eax+funcOffset] ; \ + } + + +#define CALL_THISCALL_1( resultName, thisPtr, funcOffset, param1 )\ + void *this_ = (thisPtr); \ + __asm { \ + mov eax, param1 ; \ + push eax ; \ + mov ecx, this_ ; \ + mov eax, [ecx] ; \ + call [eax+funcOffset] ; \ + mov resultName, eax ; \ + } + + +#define CALL_THISCALL_1_DOUBLE( resultName, thisPtr, funcOffset, param1 )\ + void *this_ = (thisPtr); \ + void *doubleParamPtr_ (¶m1); \ + __asm { \ + mov eax, doubleParamPtr_ ; \ + push [eax+4] ; \ + push [eax] ; \ + mov ecx, this_ ; \ + mov eax, [ecx] ; \ + call [eax+funcOffset] ; \ + mov resultName, eax ; \ + } + + +#define CALL_THISCALL_2( resultName, thisPtr, funcOffset, param1, param2 )\ + void *this_ = (thisPtr); \ + __asm { \ + mov eax, param2 ; \ + push eax ; \ + mov eax, param1 ; \ + push eax ; \ + mov ecx, this_ ; \ + mov eax, [ecx] ; \ + call [eax+funcOffset] ; \ + mov resultName, eax ; \ + } + + +#define CALL_THISCALL_4( resultName, thisPtr, funcOffset, param1, param2, param3, param4 )\ + void *this_ = (thisPtr); \ + __asm { \ + mov eax, param4 ; \ + push eax ; \ + mov eax, param3 ; \ + push eax ; \ + mov eax, param2 ; \ + push eax ; \ + mov eax, param1 ; \ + push eax ; \ + mov ecx, this_ ; \ + mov eax, [ecx] ; \ + call [eax+funcOffset] ; \ + mov resultName, eax ; \ + } + + +#elif defined(__GNUC__) + + +#define CALL_THISCALL_0( resultName, thisPtr, funcOffset ) \ + __asm__ __volatile__ ("movl (%1), %%edx\n\t" \ + "call *"#funcOffset"(%%edx)\n\t" \ + :"=a"(resultName) /* Output Operands */ \ + :"c"(thisPtr) /* Input Operands */ \ + ); \ + + +#define CALL_VOID_THISCALL_1( thisPtr, funcOffset, param1 ) \ + __asm__ __volatile__ ("pushl %0\n\t" \ + "movl (%1), %%edx\n\t" \ + "call *"#funcOffset"(%%edx)\n\t" \ + : /* Output Operands */ \ + :"r"(param1), /* Input Operands */ \ + "c"(thisPtr) \ + ); \ + + +#define CALL_THISCALL_1( resultName, thisPtr, funcOffset, param1 ) \ + __asm__ __volatile__ ("pushl %1\n\t" \ + "movl (%2), %%edx\n\t" \ + "call *"#funcOffset"(%%edx)\n\t" \ + :"=a"(resultName) /* Output Operands */ \ + :"r"(param1), /* Input Operands */ \ + "c"(thisPtr) \ + ); \ + + +#define CALL_THISCALL_1_DOUBLE( resultName, thisPtr, funcOffset, param1 ) \ + __asm__ __volatile__ ("pushl 4(%1)\n\t" \ + "pushl (%1)\n\t" \ + "movl (%2), %%edx\n\t" \ + "call *"#funcOffset"(%%edx);\n\t" \ + :"=a"(resultName) /* Output Operands */ \ + :"a"(¶m1), /* Input Operands */ \ + /* Note: Using "r" above instead of "a" fails */ \ + /* when using GCC 3.3.3, and maybe later versions*/\ + "c"(thisPtr) \ + ); \ + + +#define CALL_THISCALL_2( resultName, thisPtr, funcOffset, param1, param2 ) \ + __asm__ __volatile__ ("pushl %1\n\t" \ + "pushl %2\n\t" \ + "movl (%3), %%edx\n\t" \ + "call *"#funcOffset"(%%edx)\n\t" \ + :"=a"(resultName) /* Output Operands */ \ + :"r"(param2), /* Input Operands */ \ + "r"(param1), \ + "c"(thisPtr) \ + ); \ + + +#define CALL_THISCALL_4( resultName, thisPtr, funcOffset, param1, param2, param3, param4 )\ + __asm__ __volatile__ ("pushl %1\n\t" \ + "pushl %2\n\t" \ + "pushl %3\n\t" \ + "pushl %4\n\t" \ + "movl (%5), %%edx\n\t" \ + "call *"#funcOffset"(%%edx)\n\t" \ + :"=a"(resultName) /* Output Operands */ \ + :"r"(param4), /* Input Operands */ \ + "r"(param3), \ + "r"(param2), \ + "r"(param1), \ + "c"(thisPtr) \ + ); \ + +#endif + + + +// Our static singleton instance. +IASIOThiscallResolver IASIOThiscallResolver::instance; + +// Constructor called to initialize static Singleton instance above. Note that +// it is important not to clear that_ incase it has already been set by the call +// to placement new in ASIOInit(). +IASIOThiscallResolver::IASIOThiscallResolver() +{ +} + +// Constructor called from ASIOInit() below +IASIOThiscallResolver::IASIOThiscallResolver(IASIO* that) +: that_( that ) +{ +} + +// Implement IUnknown methods as assert(false). IASIOThiscallResolver is not +// really a COM object, just a wrapper which will work with the ASIO SDK. +// If you wanted to use ASIO without the SDK you might want to implement COM +// aggregation in these methods. +HRESULT STDMETHODCALLTYPE IASIOThiscallResolver::QueryInterface(REFIID riid, void **ppv) +{ + (void)riid; // suppress unused variable warning + + assert( false ); // this function should never be called by the ASIO SDK. + + *ppv = NULL; + return E_NOINTERFACE; +} + +ULONG STDMETHODCALLTYPE IASIOThiscallResolver::AddRef() +{ + assert( false ); // this function should never be called by the ASIO SDK. + + return 1; +} + +ULONG STDMETHODCALLTYPE IASIOThiscallResolver::Release() +{ + assert( false ); // this function should never be called by the ASIO SDK. + + return 1; +} + + +// Implement the IASIO interface methods by performing the vptr manipulation +// described above then delegating to the real implementation. +ASIOBool IASIOThiscallResolver::init(void *sysHandle) +{ + ASIOBool result; + CALL_THISCALL_1( result, that_, 12, sysHandle ); + return result; +} + +void IASIOThiscallResolver::getDriverName(char *name) +{ + CALL_VOID_THISCALL_1( that_, 16, name ); +} + +long IASIOThiscallResolver::getDriverVersion() +{ + ASIOBool result; + CALL_THISCALL_0( result, that_, 20 ); + return result; +} + +void IASIOThiscallResolver::getErrorMessage(char *string) +{ + CALL_VOID_THISCALL_1( that_, 24, string ); +} + +ASIOError IASIOThiscallResolver::start() +{ + ASIOBool result; + CALL_THISCALL_0( result, that_, 28 ); + return result; +} + +ASIOError IASIOThiscallResolver::stop() +{ + ASIOBool result; + CALL_THISCALL_0( result, that_, 32 ); + return result; +} + +ASIOError IASIOThiscallResolver::getChannels(long *numInputChannels, long *numOutputChannels) +{ + ASIOBool result; + CALL_THISCALL_2( result, that_, 36, numInputChannels, numOutputChannels ); + return result; +} + +ASIOError IASIOThiscallResolver::getLatencies(long *inputLatency, long *outputLatency) +{ + ASIOBool result; + CALL_THISCALL_2( result, that_, 40, inputLatency, outputLatency ); + return result; +} + +ASIOError IASIOThiscallResolver::getBufferSize(long *minSize, long *maxSize, + long *preferredSize, long *granularity) +{ + ASIOBool result; + CALL_THISCALL_4( result, that_, 44, minSize, maxSize, preferredSize, granularity ); + return result; +} + +ASIOError IASIOThiscallResolver::canSampleRate(ASIOSampleRate sampleRate) +{ + ASIOBool result; + CALL_THISCALL_1_DOUBLE( result, that_, 48, sampleRate ); + return result; +} + +ASIOError IASIOThiscallResolver::getSampleRate(ASIOSampleRate *sampleRate) +{ + ASIOBool result; + CALL_THISCALL_1( result, that_, 52, sampleRate ); + return result; +} + +ASIOError IASIOThiscallResolver::setSampleRate(ASIOSampleRate sampleRate) +{ + ASIOBool result; + CALL_THISCALL_1_DOUBLE( result, that_, 56, sampleRate ); + return result; +} + +ASIOError IASIOThiscallResolver::getClockSources(ASIOClockSource *clocks, long *numSources) +{ + ASIOBool result; + CALL_THISCALL_2( result, that_, 60, clocks, numSources ); + return result; +} + +ASIOError IASIOThiscallResolver::setClockSource(long reference) +{ + ASIOBool result; + CALL_THISCALL_1( result, that_, 64, reference ); + return result; +} + +ASIOError IASIOThiscallResolver::getSamplePosition(ASIOSamples *sPos, ASIOTimeStamp *tStamp) +{ + ASIOBool result; + CALL_THISCALL_2( result, that_, 68, sPos, tStamp ); + return result; +} + +ASIOError IASIOThiscallResolver::getChannelInfo(ASIOChannelInfo *info) +{ + ASIOBool result; + CALL_THISCALL_1( result, that_, 72, info ); + return result; +} + +ASIOError IASIOThiscallResolver::createBuffers(ASIOBufferInfo *bufferInfos, + long numChannels, long bufferSize, ASIOCallbacks *callbacks) +{ + ASIOBool result; + CALL_THISCALL_4( result, that_, 76, bufferInfos, numChannels, bufferSize, callbacks ); + return result; +} + +ASIOError IASIOThiscallResolver::disposeBuffers() +{ + ASIOBool result; + CALL_THISCALL_0( result, that_, 80 ); + return result; +} + +ASIOError IASIOThiscallResolver::controlPanel() +{ + ASIOBool result; + CALL_THISCALL_0( result, that_, 84 ); + return result; +} + +ASIOError IASIOThiscallResolver::future(long selector,void *opt) +{ + ASIOBool result; + CALL_THISCALL_2( result, that_, 88, selector, opt ); + return result; +} + +ASIOError IASIOThiscallResolver::outputReady() +{ + ASIOBool result; + CALL_THISCALL_0( result, that_, 92 ); + return result; +} + + +// Implement our substitute ASIOInit() method +ASIOError IASIOThiscallResolver::ASIOInit(ASIODriverInfo *info) +{ + // To ensure that our instance's vptr is correctly constructed, even if + // ASIOInit is called prior to main(), we explicitly call its constructor + // (potentially over the top of an existing instance). Note that this is + // pretty ugly, and is only safe because IASIOThiscallResolver has no + // destructor and contains no objects with destructors. + new((void*)&instance) IASIOThiscallResolver( theAsioDriver ); + + // Interpose between ASIO client code and the real driver. + theAsioDriver = &instance; + + // Note that we never need to switch theAsioDriver back to point to the + // real driver because theAsioDriver is reset to zero in ASIOExit(). + + // Delegate to the real ASIOInit + return ::ASIOInit(info); +} + + +#endif /* !defined(_MSC_VER) */ + +#endif /* Win32 */ + |