ContextErrorHandler Class Reference

A stackable ErrorHandler that prints context lines. More...

#include <error.hh>

Inheritance diagram for ContextErrorHandler:

Public Member Functions
	ContextErrorHandler (ErrorHandler *errh, const char *fmt,...)
	Construct a ContextErrorHandler.
bool	context_printed () const
	Return true iff the context has already been printed.
void	set_context_printed (bool x)
	Set whether the context has been printed.
void	set_context (const String &str)
	Set the context string to str.
void	set_indent (const String &str)
	Set the indent string to str.
void	set_context_landmark (const String &str)
	Set the context landmark to str.
String	decorate (const String &str)
	Decorate an error message.
Public Member Functions inherited from ErrorVeneer
	ErrorVeneer (ErrorHandler *errh)
	Construct an ErrorVeneer.
String	vformat (const char *fmt, va_list val)
	Format an error string.
String	decorate (const String &str)
	Decorate an error message.
void *	emit (const String &str, void *user_data, bool more)
	Output an error message line.
void	account (int level)
	Account for an error message at level level.
Public Member Functions inherited from ErrorHandler
	ErrorHandler ()
	Construct an ErrorHandler.
void	debug (const char *fmt,...)
	Print a debug message (level el_debug).
void	message (const char *fmt,...)
	Print an informational message (level el_info).
int	warning (const char *fmt,...)
	Print a warning message (level el_warning).
int	error (const char *fmt,...)
	Print an error message (level el_error).
int	fatal (const char *fmt,...)
	Print a fatal error message (level el_fatal).
void	ldebug (const String &landmark, const char *fmt,...)
	Print a debug message with a landmark annotation.
void	lmessage (const String &landmark, const char *fmt,...)
	Print an informational message with a landmark annotation.
int	lwarning (const String &landmark, const char *fmt,...)
	Print a warning message with a landmark annotation.
int	lerror (const String &landmark, const char *fmt,...)
	Print an error message with a landmark annotation.
int	lfatal (const String &landmark, const char *fmt,...)
	Print a fatal error message with a landmark annotation.
int	xmessage (const String &str)
	Print an annotated error message.
int	xmessage (const String &anno, const String &str)
	Print an error message, adding annotations.
int	xmessage (const String &anno, const char *fmt, va_list val)
	Format and print an error message, adding annotations.
int	xmessage (const String &landmark, const String &anno, const String &str)
	Print an error message, adding landmark and other annotations.
int	xmessage (const String &landmark, const String &anno, const char *fmt, va_list val)
	Format and print an error message, adding landmark and other annotations.
int	nerrors () const
	Return the number of errors reported via this handler.
String	format (const char *fmt,...)
	Format an error string.
virtual void	clear ()
	Clear accumulated error state.

Additional Inherited Members
Public Types inherited from ErrorHandler
enum	Level {   el_abort = -999 , el_fatal = -1 , el_emergency = 0 , el_alert = 1 ,   el_critical = 2 , el_error = 3 , el_warning = 4 , el_notice = 5 ,   el_info = 6 , el_debug = 7 }
	Error level constants. More...
enum	ConversionFlags {   cf_zero_pad = 1 , cf_plus_positive = 2 , cf_space_positive = 4 , cf_left_just = 8 ,   cf_alternate_form = 16 , cf_singlequote = 32 , cf_uppercase = 64 , cf_signed = 128 ,   cf_negative = 256 , cf_utf8 = 1024 }
typedef String(*	ConversionFunction) (int flags, VA_LIST_REF_T)
Static Public Member Functions inherited from ErrorHandler
static ErrorHandler *	static_initialize (ErrorHandler *errh)
	Initialize the ErrorHandler implementation.
static void	static_cleanup ()
	Tear down the ErrorHandler implementation.
static ErrorHandler *	default_handler ()
	Return the default ErrorHandler.
static void	set_default_handler (ErrorHandler *errh)
	Set the default ErrorHandler to errh.
static ErrorHandler *	silent_handler ()
	Return the global silent ErrorHandler.
static String	xformat (int default_flags, const char *fmt,...)
	Format an error string.
static String	vxformat (int default_flags, const char *fmt, va_list val)
static String	xformat (const char *fmt,...)
static String	vxformat (const char *fmt, va_list val)
static String	make_anno (const char *name, const String &value)
	Create an error annotation.
static String	combine_anno (const String &str, const String &anno)
	Apply annotations from anno to every line in str.
static const char *	parse_anno (const String &str, const char *begin, const char *end,...) ERRH_SENTINEL
	Parse error annotations from a string.
static const char *	skip_anno (const char *begin, const char *end)
	Skip a string's error annotations.
static String	make_landmark_anno (const String &x)
	Return a landmark annotation equal to x.
static String	clean_landmark (const String &landmark, bool colon=false)
	Clean the landmark.
static Conversion *	add_conversion (const String &name, ConversionFunction func)
static int	remove_conversion (Conversion *conversion)
Static Public Attributes inherited from ErrorHandler
static const char	e_abort [] = "<-999>"
	Error level indicators.
static const char	e_fatal [] = "<-1>"
static const char	e_emergency [] = "<0>"
static const char	e_alert [] = "<1>"
static const char	e_critical [] = "<2>"
static const char	e_error [] = "<3>"
static const char	e_warning [] = "<4>"
static const char	e_warning_annotated [] = "<4>warning: "
static const char	e_notice [] = "<5>"
static const char	e_info [] = "<6>"
static const char	e_debug [] = "<7>"
static const int	ok_result = 0
static const int	error_result = -EINVAL

Detailed Description

A stackable ErrorHandler that prints context lines.

The stackable ContextErrorHandler adds context to the first error message printed, and optionally indent error messages so that they appear grouped underneath the context.

FileErrorHandler errh1(stderr);
ContextErrorHandler errh2(&errh1, "While counting to 2:");
errh2.error("An error occurred.");
errh2.error("Another error occurred.");
    // prints "While counting to 2:\n"
    //        "  An error occurred.\n"
    //        "  Another error occurred.\n"

To prevent ContextErrorHandler from indenting or printing context for a message, add a "{context:no}" annotation to the message's first line. To turn off the indent but keep the context, add a "{context:noindent}" annotation.

FileErrorHandler errh1(stderr);
ContextErrorHandler errh2(&errh1, "While counting to 2:");
errh2.error("{context:no}An error occurred.");
errh2.error("Another error occurred.");
    // prints "An error occurred.\n"
    //        "While counting to 2:\n"
    //        "  Another error occurred.\n"
 
FileErrorHandler errh1(stderr);
PrefixErrorHandler noctx_errh(stderr, "{context:no}");
ContextErrorHandler errh2(&errh1, "While counting to 2:");
errh2.error("An error occurred.");
errh2.error("Another error occurred.");
    // prints "An error occurred.\n"
    //        "Another error occurred.\n"

ContextErrorHandler adds the "{context:context}" annotation to context lines.

Constructor & Destructor Documentation

ContextErrorHandler()

ContextErrorHandler::ContextErrorHandler	(	ErrorHandler *	errh,
		const char *	fmt,
			...
	)

Construct a ContextErrorHandler.

Parameters

errh	base ErrorHandler
fmt	format for context lines

The context message is formed by errh->format() using fmt and any additional arguments.

Member Function Documentation

context_printed()

bool ContextErrorHandler::context_printed ( ) const

inline

Return true iff the context has already been printed.

set_context_printed()

void ContextErrorHandler::set_context_printed ( bool  x )

inline

Set whether the context has been printed.

set_context()

void ContextErrorHandler::set_context ( const String &  str )

inline

Set the context string to str.

set_indent()

void ContextErrorHandler::set_indent ( const String &  str )

inline

Set the indent string to str.

The indent string is prepended to all non-context messages. It can contain landmarks as well as non-landmark text. The default indent string is " " (two spaces).

set_context_landmark()

void ContextErrorHandler::set_context_landmark ( const String &  str )

inline

Set the context landmark to str.

The context landmark is used to decorate the context, and also applied to any error messages that lack landmarks of their own. The default context landmark is empty.

Note

The input str is passed to ErrorHandler::make_landmark_anno().

decorate()

String ContextErrorHandler::decorate ( const String &  str )

virtual

Decorate an error message.

Parameters

str	error message, possibly with annotations

Returns

decorated error message

Warning

ErrorHandler users don't need to call this function directly; it is called implicitly by the error()/xmessage() functions.

This virtual function is called to decorate an error message before it is emitted. The input str is an error message string, possibly annotated. The default implementation returns str unchanged. Other ErrorHandlers might add context lines (ContextErrorHandler), prefixes (PrefixErrorHandler), or a default landmark (LandmarkErrorHandler).

Reimplemented from ErrorHandler.

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

• include/click/error.hh
• lib/error.cc