wxWidgets/interface/stackwalk.h

/////////////////////////////////////////////////////////////////////////////
// Name:        stackwalk.h
// Purpose:     documentation for wxStackWalker class
// Author:      wxWidgets team
// RCS-ID:      $Id$
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

/**
    @class wxStackWalker
    @wxheader{stackwalk.h}

    wxStackWalker allows an application to enumerate, or walk, the stack frames
    (the function callstack).
    It is mostly useful in only two situations:
    inside wxApp::OnFatalException function to
    programmatically get the location of the crash and, in debug builds, in
    wxApp::OnAssertFailure to report the caller of the failed
    assert.

    wxStackWalker works by repeatedly calling
    the wxStackWalker::OnStackFrame method for each frame in the
    stack, so to use it you must derive your own class from it and override this
    method.

    This class will not return anything except raw stack frame addresses if the
    debug information is not available. Under Win32 this means that the PDB file
    matching the program being executed should be present. Note that if you use
    Microsoft Visual C++ compiler, you can create PDB files even for the programs
    built in release mode and it doesn't affect the program size (at least if you
    don't forget to add @c /opt:ref option which is suppressed by using
    @c /debug linker option by default but should be always enabled for
    release builds). Under Unix, you need to compile your program with debugging
    information (usually using @c -g compiler and linker options) to get the
    file and line numbers information, however function names should be available
    even without it. Of course, all this is only @true if you build using a recent
    enough version of GNU libc which provides the @c backtrace() function
    needed to walk the stack.

    @ref overview_debuggingoverview "debugging overview" for how to make it
    available.

    @library{wxbase}
    @category{FIXME}

    @seealso
    wxStackFrame
*/
class wxStackWalker
{
public:
    /**
        Constructor does nothing, use Walk() to walk the
        stack.
    */
    wxStackWalker();

    /**
        Destructor does nothing neither but should be virtual as this class is used as
        a base one.
    */
    ~wxStackWalker();

    /**
        This function must be overrided to process the given frame.
    */
    void OnStackFrame(const wxStackFrame& frame);

    /**
        Enumerate stack frames from the current location, skipping the initial
        number of them (this can be useful when Walk() is called from some known
        location and you don't want to see the first few frames anyhow; also
        notice that Walk() frame itself is not included if skip = 1).
        Up to @a maxDepth frames are walked from the innermost to the outermost one.
    */
    void Walk(size_t skip = 1, size_t maxDepth = 200);

    /**
        Enumerate stack frames from the location of uncaught exception.
        This method can only be called from
        wxApp::OnFatalException.
        Up to @a maxDepth frames are walked from the innermost to the outermost one.
    */
    void WalkFromException(size_t maxDepth = 200);
};


/**
    @class wxStackFrame
    @wxheader{stackwalk.h}

    wxStackFrame represents a single stack frame, or a single function in the call
    stack, and is used exclusively together with
    wxStackWalker, see there for a more detailed
    discussion.

    @library{wxbase}
    @category{FIXME}

    @seealso
    wxStackWalker
*/
class wxStackFrame
{
public:
    /**
        Return the address of this frame.
    */
    void* GetAddress() const;

    /**
        Return the name of the file containing this frame, empty if
        unavailable (typically because debug info is missing).
        Use HasSourceLocation() to check whether
        the file name is available.
    */
    wxString GetFileName() const;

    /**
        Get the level of this frame (deepest/innermost one is 0).
    */
    size_t GetLevel() const;

    /**
        Return the line number of this frame, 0 if unavailable.
        
        @see GetFileName()
    */
    size_t GetLine() const;

    /**
        Get the module this function belongs to (empty if not available).
    */
    wxString GetModule() const;

    /**
        Return the unmangled (if possible) name of the function containing this
        frame.
    */
    wxString GetName() const;

    /**
        Return the return address of this frame.
    */
    size_t GetOffset() const;

    /**
        Get the name, type and value (in text form) of the given parameter.
        Any pointer may be @NULL if you're not interested in the corresponding
        value.
        Return @true if at least some values could be retrieved.
        This function currently is only implemented under Win32 and requires a PDB
        file.
    */
    bool GetParam(size_t n, wxString* type, wxString* name,
                  wxString* value) const;

    /**
        Return the number of parameters of this function (may return 0 if we
        can't retrieve the parameters info even although the function does have
        parameters).
    */
    size_t GetParamCount() const;

    /**
        Return @true if we have the file name and line number for this frame.
    */
    bool HasSourceLocation() const;
};