Imported from /home/lorry/working-area/delta_ntp/ntp-dev-4.2.7p482.tar.gz.ntp-dev-4.2.7p482

1 files changed, 131 insertions, 0 deletions

diff --git a/lib/isc/include/isc/backtrace.h b/lib/isc/include/isc/backtrace.h
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+/*
+ * Copyright (C) 2009  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: backtrace.h,v 1.2 2009/09/01 18:40:25 jinmei Exp $ */
+
+/*! \file isc/backtrace.h
+ * \brief provide a back trace of the running process to help debug problems.
+ *
+ * This module tries to get a back trace of the process using some platform
+ * dependent way when available.  It also manages an internal symbol table
+ * that maps function addresses used in the process to their textual symbols.
+ * This module is expected to be used to help debug when some fatal error
+ * happens.
+ *
+ * IMPORTANT NOTE: since the (major) intended use case of this module is
+ * dumping a back trace on a fatal error, normally followed by self termination,
+ * functions defined in this module generally doesn't employ assertion checks
+ * (if it did, a program bug could cause infinite recursive calls to a
+ * backtrace function).  These functions still perform minimal checks and return
+ * ISC_R_FAILURE if they detect an error, but the caller should therefore be
+ * very careful about the use of these functions, and generally discouraged to
+ * use them except in an exit path.  The exception is
+ * isc_backtrace_getsymbolfromindex(), which is expected to be used in a
+ * non-error-handling context and validates arguments with assertion checks.
+ */
+
+#ifndef ISC_BACKTRACE_H
+#define ISC_BACKTRACE_H 1
+
+/***
+ ***	Imports
+ ***/
+
+#include <isc/types.h>
+
+/***
+ *** Types
+ ***/
+struct isc_backtrace_symmap {
+	void		*addr;
+	const char	*symbol;
+};
+
+extern const int isc__backtrace_nsymbols;
+extern const isc_backtrace_symmap_t isc__backtrace_symtable[];
+
+/***
+ *** Functions
+ ***/
+
+ISC_LANG_BEGINDECLS
+isc_result_t
+isc_backtrace_gettrace(void **addrs, int maxaddrs, int *nframes);
+/*%<
+ * Get a back trace of the running process above this function itself.  On
+ * success, addrs[i] will store the address of the call point of the i-th
+ * stack frame (addrs[0] is the caller of this function).  *nframes will store
+ * the total number of frames.
+ *
+ * Requires (note that these are not ensured by assertion checks, see above):
+ *
+ *\li	'addrs' is a valid array containing at least 'maxaddrs' void * entries.
+ *
+ *\li	'nframes' must be non NULL.
+ *
+ * Returns:
+ *
+ *\li	#ISC_R_SUCCESS
+ *\li	#ISC_R_FAILURE
+ *\li	#ISC_R_NOTFOUND
+ *\li	#ISC_R_NOTIMPLEMENTED
+ */
+
+isc_result_t
+isc_backtrace_getsymbolfromindex(int index, const void **addrp,
+				 const char **symbolp);
+/*%<
+ * Returns the content of the internal symbol table of the given index.
+ * On success, *addrsp and *symbolp point to the address and the symbol of
+ * the 'index'th entry of the table, respectively.  If 'index' is not in the
+ * range of the symbol table, ISC_R_RANGE will be returned.
+ *
+ * Requires
+ *
+ *\li	'addrp' must be non NULL && '*addrp' == NULL.
+ *
+ *\li	'symbolp' must be non NULL && '*symbolp' == NULL.
+ *
+ * Returns:
+ *
+ *\li	#ISC_R_SUCCESS
+ *\li	#ISC_R_RANGE
+ */
+
+isc_result_t
+isc_backtrace_getsymbol(const void *addr, const char **symbolp,
+			unsigned long *offsetp);
+/*%<
+ * Searches the internal symbol table for the symbol that most matches the
+ * given 'addr'.  On success, '*symbolp' will point to the name of function
+ * to which the address 'addr' belong, and '*offsetp' will store the offset
+ * from the function's entry address to 'addr'.
+ *
+ * Requires (note that these are not ensured by assertion checks, see above):
+ *
+ *\li	'symbolp' must be non NULL && '*symbolp' == NULL.
+ *
+ *\li	'offsetp' must be non NULL.
+ *
+ * Returns:
+ *
+ *\li	#ISC_R_SUCCESS
+ *\li	#ISC_R_FAILURE
+ *\li	#ISC_R_NOTFOUND
+ */
+ISC_LANG_ENDDECLS
+
+#endif	/* ISC_BACKTRACE_H */