Backtrace Class Reference

A Backtrace represents a backtrace of the run-time stack. More...

#include <Backtrace.h>

List of all members.

Public Member Functions
	Backtrace (size_t maxdepth=32)
	Captures the backtrace at the point of construction.
	Backtrace (size_t bufsize, void **buffer)
	Captures the backtrace at the point of construction.
	~Backtrace ()
std::ostream &	print (std::ostream &) const
	Prints the backtrace in human readable form.
void	print (int fd) const
	Prints the backtrace to a unix file descriptor: for use when out of memory.
Static Public Member Functions
static void	writeDemangled (std::ostream &out, char const *pMangled)
	Attempts to demangle a C++ name and write it to an ostream.
Static Private Member Functions
static int	lookupLibraryBase (struct dl_phdr_info *, size_t, void *)
Private Attributes
size_t	depth
const bool	ownbuf
const size_t	bufsize
void **	addrbuf
Classes
struct	LibraryInfo

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Detailed Description

A Backtrace represents a backtrace of the run-time stack.

The constructor wraps up the backtrace of the current thread at the point of construction. A Backtrace object can be printed to an ostream.

Definition at line 46 of file Backtrace.h.

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Constructor & Destructor Documentation

Backtrace::Backtrace

(

size_t

maxdepth = 32

)

Captures the backtrace at the point of construction.

The Backtrace object allocates its own address buffer.

Parameters:

maxdepth

maximum depth of backtrace

Definition at line 46 of file Backtrace.cpp.

References addrbuf, bufsize, and depth.

    : ownbuf(true), bufsize(maxdepth + 1)
{
#ifndef __MSVC__
    addrbuf = new void * [bufsize];
    depth = backtrace(addrbuf, bufsize);
#endif
}

Backtrace::Backtrace	(	size_t	bufsize,
		void **	buffer
	)

Captures the backtrace at the point of construction.

The caller provides an address buffer, probably on the stack.

The buffer should contain an extra item to refer to the Backtrace constructor itself.

Parameters:

	bufsize	buffer size, in words (sizeof(void*) = 1 word)
	buffer	an array of BUFSIZE (void *) entries.

Definition at line 55 of file Backtrace.cpp.

References addrbuf, and depth.

    : ownbuf(false), bufsize(bufsize)
{
#ifndef __MSVC__
    addrbuf = buffer;
    depth = backtrace(addrbuf, bufsize);
#endif
}

Backtrace::~Backtrace

(

)

Definition at line 39 of file Backtrace.cpp.

References addrbuf, and ownbuf.

{
    if (ownbuf) {
        delete[] addrbuf;
    }
}

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Member Function Documentation

int Backtrace::lookupLibraryBase	(	struct dl_phdr_info *	,
		size_t	,
		void *
	)			[static, private]

Definition at line 78 of file Backtrace.cpp.

References Backtrace::LibraryInfo::pImageName.

{
    LibraryInfo *pLibInfo = reinterpret_cast<LibraryInfo *>(pData);
    if (strcmp(pLibInfo->pImageName, pInfo->dlpi_name) == 0) {
        pLibInfo->baseAddress = pInfo->dlpi_addr;
        return 1;
    }
    return 0;
}

std::ostream& Backtrace::print

(

std::ostream &

)

const

Prints the backtrace in human readable form.

Skips the Backtrace constructor.

Referenced by operator<<().

void Backtrace::print

(

int

fd

)

const

Prints the backtrace to a unix file descriptor: for use when out of memory.

Definition at line 67 of file Backtrace.cpp.

References addrbuf, and depth.

{
#ifndef __MSVC__
    // skip 1st stack frame (the Backtrace constructor)
    if (depth > 1) {
        backtrace_symbols_fd(addrbuf + 1, depth - 1, fd);
    }
#endif
}

void Backtrace::writeDemangled	(	std::ostream &	out,
		char const *	pMangled
	)			[static]

Attempts to demangle a C++ name and write it to an ostream.

Parameters:

	out	receives demangled name
	pMangled	name to be demangled

Definition at line 173 of file Backtrace.cpp.

References free().

Referenced by ExecStreamGraphImpl::DotVertexRenderer::operator()().

{
    int status = -3;
    char *pDemangled = NULL;
#ifndef __MSVC__
    pDemangled =
        abi::__cxa_demangle(pMangled, NULL, NULL, &status);
#endif
    if (status || !pDemangled) {
        // non-zero status means demangling failed;
        // use mangled name instead
        out << pMangled;
    } else {
        out << pDemangled;
        free(pDemangled);
    }
}

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Member Data Documentation

size_t Backtrace::depth [private]

Definition at line 48 of file Backtrace.h.

Referenced by Backtrace(), and print().

const bool Backtrace::ownbuf [private]

Definition at line 49 of file Backtrace.h.

Referenced by ~Backtrace().

const size_t Backtrace::bufsize [private]

Definition at line 50 of file Backtrace.h.

Referenced by Backtrace().

void** Backtrace::addrbuf [private]

Definition at line 51 of file Backtrace.h.

Referenced by Backtrace(), print(), and ~Backtrace().

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The documentation for this class was generated from the following files:

• /home/pub/open/dev/fennel/common/Backtrace.h
• /home/pub/open/dev/fennel/common/Backtrace.cpp

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