lar::debug Namespace Reference

Namespaces
	details

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...
struct	static_assert_on
struct	static_assert_on< T, false >

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 348 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 394 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 403 of file DebugUtils.h.

                                                                   {
    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 236 of file DebugUtils.h.

    { 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 445 of file DebugUtils.h.

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