void PE_Debug :: FindDebugInfo()
{
ClearDebugPtrs() ;
// Put everything into a try/catch in case the file has wrong fields
try
{
// Verify that fileBase is a valid pointer to a DOS header
if( fileBase->e_magic == IMAGE_DOS_SIGNATURE )
{
// Get a pointer to the PE header
NT_Header = BasedPtr( PIMAGE_NT_HEADERS, fileBase, fileBase->e_lfanew ) ;
// Verify that NT_Header is a valid pointer to a NT header
if( NT_Header->Signature == IMAGE_NT_SIGNATURE )
{
// Get a pointer to the debug header if any
COFFDebugInfo = GetDebugHeader() ;
// Get a pointer to the symbol table and retrieve the number of symbols
if( NT_Header->FileHeader.PointerToSymbolTable )
COFFSymbolTable =
BasedPtr( PIMAGE_SYMBOL, fileBase, NT_Header->FileHeader.PointerToSymbolTable ) ;
COFFSymbolCount = NT_Header->FileHeader.NumberOfSymbols ;
// The string table starts right after the symbol table
stringTable = (const char*)(COFFSymbolTable + COFFSymbolCount) ;
}
}
}
catch( ... )
{
// Header wrong, do nothing
}
}
void PE_Debug :: DumpLineNumber(std::ostream& dumpBuffer, DWORD relativeAddress )
{
PIMAGE_LINENUMBER line = BasedPtr( PIMAGE_LINENUMBER, COFFDebugInfo,
COFFDebugInfo->LvaToFirstLinenumber ) ;
DWORD lineCount = COFFDebugInfo->NumberOfLinenumbers ;
const DWORD none = (DWORD)-1 ;
DWORD maxAddr = 0 ;
DWORD lineNum = none ;
for( DWORD i=0; i < lineCount; i++ )
{
if( line->Linenumber != 0 ) // A regular line number
{
// look for line with bigger address <= relativeAddress
if( line->Type.VirtualAddress <= relativeAddress &&
line->Type.VirtualAddress > maxAddr )
{
maxAddr = line->Type.VirtualAddress ;
lineNum = line->Linenumber ;
}
}
line++ ;
}
if( lineNum != none ) {
dumpBuffer << " line " << lineNum << "\n";
}
}
void PE_Debug :: DumpLineNumber( DumpBuffer& dumpBuffer, DWORD relativeAddress )
{
PIMAGE_LINENUMBER line = BasedPtr( PIMAGE_LINENUMBER, COFFDebugInfo,
COFFDebugInfo->LvaToFirstLinenumber ) ;
DWORD lineCount = COFFDebugInfo->NumberOfLinenumbers ;
const DWORD none = (DWORD)-1 ;
DWORD maxAddr = 0 ;
DWORD lineNum = none ;
for( DWORD i=0; i < lineCount; i++ )
{
if( line->Linenumber != 0 ) // A regular line number
{
// look for line with bigger address <= relativeAddress
if( line->Type.VirtualAddress <= relativeAddress &&
line->Type.VirtualAddress > maxAddr )
{
maxAddr = line->Type.VirtualAddress ;
lineNum = line->Linenumber ;
}
}
line++ ;
}
if( lineNum != none ) {
dumpBuffer.Printf( " line %d\r\n", lineNum ) ;
if (Dump_to_log) {
mprintf(( " line %d\r\n", lineNum )) ;
}
}
// else
// dumpBuffer.Printf( " line <unknown>\r\n" ) ;
}
PIMAGE_COFF_SYMBOLS_HEADER PE_Debug :: GetDebugHeader()
{
// Some files have a wrong entry in the COFF header, so
// first check if the debug info exists at all
if( NT_Header->FileHeader.PointerToSymbolTable == 0 )
return( 0 ) ;
DWORD debugDirRVA = NT_Header->OptionalHeader.
DataDirectory[ IMAGE_DIRECTORY_ENTRY_DEBUG ].
VirtualAddress;
if( debugDirRVA == 0 )
return( 0 ) ;
// The following values must be calculated differently for MS/Borland files
PIMAGE_DEBUG_DIRECTORY debugDir ;
DWORD size ;
// Borland files have the debug directory at the beginning of a .debug section
PIMAGE_SECTION_HEADER debugHeader = SectionHeaderFromName( ".debug" ) ;
if( debugHeader && debugHeader->VirtualAddress == debugDirRVA )
{
debugDir = (PIMAGE_DEBUG_DIRECTORY)(debugHeader->PointerToRawData + (DWORD)fileBase) ;
size = NT_Header->OptionalHeader.
DataDirectory[ IMAGE_DIRECTORY_ENTRY_DEBUG ].Size *
sizeof( IMAGE_DEBUG_DIRECTORY ) ;
}
else
// Microsoft debug directory is in the .rdata section
{
debugHeader = SectionHeaderFromName( ".rdata" ) ;
if( debugHeader == 0 )
return( 0 ) ;
size = NT_Header->OptionalHeader.
DataDirectory[ IMAGE_DIRECTORY_ENTRY_DEBUG ].Size ;
DWORD offsetInto_rdata = debugDirRVA - debugHeader->VirtualAddress ;
debugDir = BasedPtr( PIMAGE_DEBUG_DIRECTORY, fileBase,
debugHeader->PointerToRawData + offsetInto_rdata ) ;
}
// look for COFF debug info
DWORD debugFormats = size / sizeof( IMAGE_DEBUG_DIRECTORY ) ;
for( DWORD i = 0; i < debugFormats; i++ )
{
if( debugDir->Type == IMAGE_DEBUG_TYPE_COFF )
return( (PIMAGE_COFF_SYMBOLS_HEADER)((DWORD)fileBase + debugDir->PointerToRawData) ) ;
else
debugDir++ ;
}
return( NULL ) ;
}
