IDiaSegment

Article
01/12/2024

Maps data from the section number to segments of address space.

Syntax

IDiaSegment : IUnknown

Methods in Vtable Order

The following table shows the methods of IDiaSegment.

Method	Description
IDiaSegment::get_frame	Retrieves the segment number.
IDiaSegment::get_offset	Retrieves the offset in segments where the section begins.
IDiaSegment::get_length	Retrieves the number of bytes in the segment.
IDiaSegment::get_read	Retrieves a flag that indicates whether the segment can be read.
IDiaSegment::get_write	Retrieves a flag that indicates whether the segment can be modified.
IDiaSegment::get_execute	Retrieves a flag that indicates whether the segment is executable.
IDiaSegment::get_addressSection	Retrieves the section number that maps to this segment.
IDiaSegment::get_relativeVirtualAddress	Retrieves the relative virtual address (RVA) of the beginning of the section.
IDiaSegment::get_virtualAddress	Retrieves the virtual address (VA) of the beginning of the section.

Remarks

Because the Debug Interface Access (DIA) SDK already performs translations from the section offset to relative virtual addresses, most applications will not make use of the information in the segment map.

Notes for Callers

Obtain this interface by calling the IDiaEnumSegments::Item or IDiaEnumSegments::Next methods. See the example for details.

Example

This function displays the address of all segments in a table and the nearest symbol.

void ShowSegments(IDiaTable *pTable, IDiaSession *pSession)
{
    CComPtr<IDiaEnumSegments> pSegments;
    if ( SUCCEEDED( pTable->QueryInterface(
                                _uuidof( IDiaEnumSegments ),
                               (void**)&pSegments )
                  )
       )
    {
        CComPtr<IDiaSegment> pSegment;
        while ( SUCCEEDED( hr = pSegments->Next( 1, &pSegment, &celt ) ) &&
                celt == 1 )
        {
            DWORD rva;
            DWORD seg;

            pSegment->get_addressSection( &seg );
            if ( pSegment->get_relativeVirtualAddress( &rva ) == S_OK )
            {
                printf( "Segment %i addr: 0x%.8X\n", seg, rva );
                pSegment = NULL;

                CComPtr<IDiaSymbol> pSym;
                if ( psession->findSymbolByRVA( rva, SymTagNull, &pSym ) == S_OK )
                {
                    CDiaBSTR name;
                    DWORD    tag;

                    pSym->get_symTag( &tag );
                    pSym->get_name( &name );
                    printf( "\tClosest symbol: %ws (%ws)\n",
                            name != NULL ? name : L"",
                            szTags[ tag ] );
                }
            }
        }
    }
}

Requirements

Header: Dia2.h

Library: diaguids.lib

DLL: msdia80.dll

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