bridges/source/cpp_uno/mingw_intel/callvirtualmethod.cxx

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  28
  29 #include "sal/config.h"
  30
  31 #include "cppu/macros.hxx"
  32 #include "osl/diagnose.h"
  33 #include "sal/types.h"
  34 #include "typelib/typeclass.h"
  35 #include "typelib/typedescription.h"
  36
  37 #include "callvirtualmethod.hxx"
  38 #include "share.hxx"
  39 #include "smallstruct.hxx"
  40
  41 // For some reason, callVirtualMethod needs to be in a source file of its own,
  42 // so that stack unwinding upon a thrown exception from within the asm block
  43 // call works, at least with GCC 4.7.0 and --enable-dbgutil.
  44
  45 // The call instruction within the asm section of callVirtualMethod may throw
  46 // exceptions.  So that the compiler handles this correctly, it is important
  47 // that (a) callVirtualMethod might call dummy_can_throw_anything (although this
  48 // never happens at runtime), which in turn can throw exceptions, and (b)
  49 // callVirtualMethod is not inlined at its call site (so that any exceptions are
  50 // caught which are thrown from the instruction calling callVirtualMethod).  [It
  51 // is unclear how much of this comment is still relevent -- see the above
  52 // comment.]
  53 void CPPU_CURRENT_NAMESPACE::callVirtualMethod(
  54     void * pAdjustedThisPtr, sal_Int32 nVtableIndex, void * pRegisterReturn,
  55     typelib_TypeDescription const * returnType, sal_Int32 * pStackLongs,
  56     sal_Int32 nStackLongs)
  57 {
  58     // parameter list is mixed list of * and values
  59     // reference parameters are pointers
  60
  61     OSL_ENSURE( pStackLongs && pAdjustedThisPtr, "### null ptr!" );
  62     OSL_ENSURE( (sizeof(void *) == 4) && (sizeof(sal_Int32) == 4), "### unexpected size of int!" );
  63     OSL_ENSURE( nStackLongs && pStackLongs, "### no stack in callVirtualMethod !" );
  64
  65     // never called
  66     if (! pAdjustedThisPtr) CPPU_CURRENT_NAMESPACE::dummy_can_throw_anything("xxx"); // address something
  67
  68     volatile long edx = 0, eax = 0; // for register returns
  69     void * stackptr;
  70     asm volatile (
  71         "mov   %%esp, %6\n\t"
  72         // copy values
  73         "mov   %0, %%eax\n\t"
  74         "mov   %%eax, %%edx\n\t"
  75         "dec   %%edx\n\t"
  76         "shl   $2, %%edx\n\t"
  77         "add   %1, %%edx\n"
  78         "Lcopy:\n\t"
  79         "pushl 0(%%edx)\n\t"
  80         "sub   $4, %%edx\n\t"
  81         "dec   %%eax\n\t"
  82         "jne   Lcopy\n\t"
  83         // do the actual call
  84         "mov   %2, %%edx\n\t"
  85         "mov   0(%%edx), %%edx\n\t"
  86         "mov   %3, %%eax\n\t"
  87         "shl   $2, %%eax\n\t"
  88         "add   %%eax, %%edx\n\t"
  89         "mov   0(%%edx), %%edx\n\t"
  90         "call  *%%edx\n\t"
  91         // save return registers
  92          "mov   %%eax, %4\n\t"
  93          "mov   %%edx, %5\n\t"
  94         // cleanup stack
  95         "mov   %6, %%esp\n\t"
  96         :
  97         : "m"(nStackLongs), "m"(pStackLongs), "m"(pAdjustedThisPtr),
  98           "m"(nVtableIndex), "m"(eax), "m"(edx), "m"(stackptr)
  99         : "eax", "ecx", "edx" );
 100     switch( returnType->eTypeClass )
 101     {
 102         case typelib_TypeClass_VOID:
 103             break;
 104         case typelib_TypeClass_HYPER:
 105         case typelib_TypeClass_UNSIGNED_HYPER:
 106             ((long*)pRegisterReturn)[1] = edx;
 107         case typelib_TypeClass_LONG:
 108         case typelib_TypeClass_UNSIGNED_LONG:
 109         case typelib_TypeClass_CHAR:
 110         case typelib_TypeClass_ENUM:
 111             ((long*)pRegisterReturn)[0] = eax;
 112             break;
 113         case typelib_TypeClass_SHORT:
 114         case typelib_TypeClass_UNSIGNED_SHORT:
 115             *(unsigned short*)pRegisterReturn = eax;
 116             break;
 117         case typelib_TypeClass_BOOLEAN:
 118         case typelib_TypeClass_BYTE:
 119             *(unsigned char*)pRegisterReturn = eax;
 120             break;
 121         case typelib_TypeClass_FLOAT:
 122             asm ( "fstps %0" : : "m"(*(char *)pRegisterReturn) );
 123             break;
 124         case typelib_TypeClass_DOUBLE:
 125             asm ( "fstpl %0\n\t" : : "m"(*(char *)pRegisterReturn) );
 126             break;
 127         case typelib_TypeClass_STRUCT:
 128             if (bridges::cpp_uno::shared::isSmallStruct(returnType)) {
 129                         if (returnType->nSize <= 1) {
 130                     *(unsigned char*)pRegisterReturn = eax;
 131                     }
 132                     else if (returnType->nSize <= 2) {
 133                     *(unsigned short*)pRegisterReturn = eax;
 134                     }
 135                         else if (returnType->nSize <= 8) {
 136                     ((long*)pRegisterReturn)[0] = eax;
 137                         if (returnType->nSize > 4) {
 138                         ((long*)pRegisterReturn)[1] = edx;
 139                     }
 140                            }
 141                 }
 142             break;
 143         default:
 144         break;
 145     }
 146 }
 147
 148 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */