On Tue, Mar 16, 2021 at 8:25 AM Alex White <alex.wh...@oarcorp.com> wrote:
>
> Occasionally the compiler will generate symbols that look similar to
> symbols defined in RTEMS code except that they contain some suffix.
> These symbol suffixes are only found in the ELF symbol table; the
> symbols appear to be normal in the DWARF info. This appears to be
> happening on all architectures.
>
> For example, the function _Message_queue_Create from rtems appears as
> "_Message_queue_Create.part.0". Other suffixes include ".isra.0",
> ".constprop.0", and ".0".
>
Do any non-compiler-generated symbols include "."?
Are there symbols that start with a "." that might be caught? I know
we do this in assembly programming often, e.g., ".vectors", although
probably it is unlikely to appear in C/asm I just want to be thorough.
> This looks to be related to compiler optimizations. Symbols with
> suffixes were being treated as unique. For our purposes, they should be
> mapped to the equivalent symbols in the DWARF info. This has been
> fixed.
> ---
> tester/covoar/ExecutableInfo.cc | 22 +++++++++++++++++++---
> tester/covoar/ObjdumpProcessor.cc | 6 ++++++
> tester/covoar/SymbolTable.cc | 12 +++++++++---
> 3 files changed, 34 insertions(+), 6 deletions(-)
>
> diff --git a/tester/covoar/ExecutableInfo.cc b/tester/covoar/ExecutableInfo.cc
> index c996d75..9384973 100644
> --- a/tester/covoar/ExecutableInfo.cc
> +++ b/tester/covoar/ExecutableInfo.cc
> @@ -118,8 +118,7 @@ namespace Coverage {
> // Obtain the coverage map containing the specified address.
> itsSymbol = theSymbolTable.getSymbol( address );
> if (itsSymbol != "") {
> - it = coverageMaps.find( itsSymbol );
> - aCoverageMap = (*it).second;
> + aCoverageMap = &findCoverageMap(itsSymbol);
> }
>
> return aCoverageMap;
> @@ -150,8 +149,25 @@ namespace Coverage {
> )
> {
> CoverageMaps::iterator cmi = coverageMaps.find( symbolName );
> - if ( cmi == coverageMaps.end() )
> + if ( cmi != coverageMaps.end() ) {
> + return *(cmi->second);
> + }
> +
> + size_t periodIndex = symbolName.find(".");
> +
> + if (periodIndex == std::string::npos) {
> + // Symbol name has no '.', can't do another lookup.
> throw CoverageMapNotFoundError(symbolName);
> + }
> +
> + cmi = coverageMaps.find(
> + symbolName.substr(0, periodIndex)
> + );
> +
> + if ( cmi == coverageMaps.end() ) {
> + throw CoverageMapNotFoundError(symbolName);
> + }
> +
> return *(cmi->second);
> }
>
> diff --git a/tester/covoar/ObjdumpProcessor.cc
> b/tester/covoar/ObjdumpProcessor.cc
> index fa9894d..544bfa1 100644
> --- a/tester/covoar/ObjdumpProcessor.cc
> +++ b/tester/covoar/ObjdumpProcessor.cc
> @@ -417,6 +417,12 @@ namespace Coverage {
> processSymbol = false;
> theInstructions.clear();
>
> + // Look for a '.' character and strip everything after it.
> + char *periodIndex = strstr(symbol, ".");
> + if (periodIndex != NULL) {
> + *periodIndex = 0;
> + }
> +
> // See if the new symbol is one that we care about.
> if (SymbolsToAnalyze->isDesired( symbol )) {
> currentSymbol = symbol;
> diff --git a/tester/covoar/SymbolTable.cc b/tester/covoar/SymbolTable.cc
> index 53bc8af..00062cc 100644
> --- a/tester/covoar/SymbolTable.cc
> +++ b/tester/covoar/SymbolTable.cc
> @@ -46,12 +46,18 @@ namespace Coverage {
> symbolData.startingAddress = start;
> symbolData.length = length;
>
> - if ( info[ symbol ].empty() == false ) {
> - if ( info[ symbol ].front().length != length ) {
> + for (auto& symData : info[ symbol ]) {
> + // The starting address could differ since we strip any suffixes
> beginning
> + // with a '.'
> + if (symData.startingAddress != start) {
> + continue;
> + }
> +
> + if (symData.length != length) {
> std::ostringstream what;
> what << "Different lengths for the symbol "
> << symbol
> - << " (" << info[ symbol ].front().length
> + << " (" << symData.length
> << " and " << length
> << ")";
> throw rld::error( what, "SymbolTable::addSymbol" );
> --
> 2.27.0
>
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