lar::debug Namespace Reference

Classes
struct	BacktracePrintOptions
	Backtrace printing options. More...
struct	CallInfo_t
	Structure with information about a single call, parsed. More...
class	CallInfoPrinter
	Class handling the output of information in a CallInfo_t object. More...

Functions
template<typename T >
std::string	demangle (T const *=nullptr)
	Outputs a demangled name for type T. More...
template<typename Stream >
Stream &	operator<< (Stream &&out, CallInfo_t const &info)
	Helper operator to insert a call information in a stream with default options. More...
template<typename Stream >
void	printBacktrace (Stream &&out, BacktracePrintOptions options)
	Prints the full backtrace into a stream. More...
template<typename Stream >
void	printBacktrace (Stream &&out)
	Prints the full backtrace into a stream with default options. More...
template<typename Stream >
void	printBacktrace (Stream &&out, unsigned int maxLines, std::string indent=" ", CallInfoPrinter::opt const *callInfoOptions=nullptr)
	Prints the full backtrace into a stream. More...

Function Documentation

template<typename T >

std::string lar::debug::demangle ( T const *  = nullptr )

inline

Outputs a demangled name for type T.

---

Template Parameters

T	type whose name must be demangled (optional)

Returns

a string with demangled name

It relies on cetlib. The type to be demangled can be specified either as template argument:

auto name = lar::debug::demangle<std::string>();

or via a argument pointer:

auto name = lar::debug::demangle(this);

Definition at line 56 of file DebugUtils.h.

      { return cet::demangle_symbol(typeid(std::decay_t<T>).name()); }

template<typename Stream >

Stream& lar::debug::operator<< ( Stream &&  out, CallInfo_t const &  info  )

inline

Helper operator to insert a call information in a stream with default options.

Definition at line 228 of file DebugUtils.h.

      {
        CallInfoPrinter print;
        print(std::forward<Stream>(out), info);
        return out;
      }

template<typename Stream >

void lar::debug::printBacktrace	(	Stream &&	out,
		BacktracePrintOptions	options
	)

Prints the full backtrace into a stream.

Template Parameters

Stream

type of output stream

Parameters

out	the output stream to insert output into
options	printing options (see BacktracePrintOptions)

Definition at line 262 of file DebugUtils.h.

References lar::debug::BacktracePrintOptions::callInfoOptions, lar::debug::BacktracePrintOptions::countOthers, lar::debug::BacktracePrintOptions::firstIndent, lar::debug::BacktracePrintOptions::indent, max, lar::debug::BacktracePrintOptions::maxLines, and lar::debug::BacktracePrintOptions::skipLines.

Referenced by printBacktrace().

                                                                     {
      unsigned int nSkip = std::max(options.skipLines, 0U);
      std::vector<void*> buffer
        (nSkip + std::max(options.maxLines, 200U), nullptr);
      
      unsigned int const nItems
        = (unsigned int) backtrace(buffer.data(), buffer.size());
      
      // convert the calls in the buffer into a vector of strings
      char** symbols = backtrace_symbols(buffer.data(), buffer.size());
      if (!symbols) {
        out << options.firstIndent << "<failed to get the call stack>\n"
          << std::flush;
        return;
      }
      std::vector<CallInfo_t> callStack;
      for (size_t i = 0; i < buffer.size(); ++i)
        callStack.push_back((const char*) symbols[i]);
      std::free(symbols);
      
      size_t lastItem = nSkip + options.maxLines;
      if (lastItem > nItems) lastItem = nItems;
      if (lastItem >= buffer.size()) --lastItem;
      
      CallInfoPrinter print(options.callInfoOptions);
      for (size_t i = nSkip; i < lastItem; ++i) {
        out << (i == 0? options.firstIndent: options.indent);
        print(std::forward<Stream>(out), callStack[i]);
        out << "\n";
      }
      if ((lastItem < nItems) && options.countOthers) {
        out << options.indent << " ... and other " << (nItems - lastItem);
        if (nItems == buffer.size()) out << " (or more)";
        out << " levels\n";
      }
      out << std::flush;
      
    } // printBacktrace()

template<typename Stream >

void lar::debug::printBacktrace

(

Stream &&

out

)

Prints the full backtrace into a stream with default options.

Template Parameters

Stream

type of output stream

Parameters

out	the output stream to insert output into

Definition at line 307 of file DebugUtils.h.

References printBacktrace().

      { printBacktrace(std::forward<Stream>(out), BacktracePrintOptions()); }

template<typename Stream >

void lar::debug::printBacktrace	(	Stream &&	out,
		unsigned int	maxLines,
		std::string	indent = "  ",
		CallInfoPrinter::opt const *	callInfoOptions = nullptr
	)

Prints the full backtrace into a stream.

Template Parameters

Stream

type of output stream

Parameters

out	the output stream to insert output into
maxLines	print at most this many lines in the output (default: 5)
indent	prepend a string in front of any new line (default: " ")
callInfoOptions	use these output options (default ones if null)

The call information output options are described in CallInfoPrinter::opt structure.

Definition at line 323 of file DebugUtils.h.

References lar::debug::BacktracePrintOptions::callInfoOptions, lar::debug::BacktracePrintOptions::firstIndent, art::detail::indent(), lar::debug::BacktracePrintOptions::indent, lar::debug::BacktracePrintOptions::maxLines, and printBacktrace().

    {
      BacktracePrintOptions options;
      options.maxLines = maxLines;
      options.indent = options.firstIndent = indent;
      if (callInfoOptions) options.callInfoOptions = *callInfoOptions;
      printBacktrace(std::forward<Stream>(out), options);
    }