porting_aix.hpp revision 5969:666e6ce3976c 
1/*
2 * Copyright 2012, 2013 SAP AG. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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23 */
24
25#include <stddef.h>
26
27// Header file to contain porting-relevant code which does not have a
28// home anywhere else and which can not go into os_<platform>.h because
29// that header is included inside the os class definition, hence all
30// its content is part of the os class.
31
32// Aix' own version of dladdr().
33// This function tries to mimick dladdr(3) on Linux
34// (see http://linux.die.net/man/3/dladdr)
35// dladdr(3) is not POSIX but a GNU extension, and is not available on AIX.
36//
37// Differences between AIX dladdr and Linux dladdr:
38//
39// 1) Dl_info.dli_fbase: can never work, is disabled.
40//   A loaded image on AIX is divided in multiple segments, at least two
41//   (text and data) but potentially also far more. This is because the loader may
42//   load each member into an own segment, as for instance happens with the libC.a
43// 2) Dl_info.dli_sname: This only works for code symbols (functions); for data, a
44//   zero-length string is returned ("").
45// 3) Dl_info.dli_saddr: For code, this will return the entry point of the function,
46//   not the function descriptor.
47
48typedef struct {
49  const char *dli_fname; // file path of loaded library
50  // void *dli_fbase;
51  const char *dli_sname; // symbol name; "" if not known
52  void *dli_saddr;       // address of *entry* of function; not function descriptor;
53} Dl_info;
54
55// Note: we export this to use it inside J2se too
56#ifdef __cplusplus
57extern "C"
58#endif
59int dladdr(void *addr, Dl_info *info);
60
61
62// The semantics in this file are thus that codeptr_t is a *real code ptr*.
63// This means that any function taking codeptr_t as arguments will assume
64// a real codeptr and won't handle function descriptors (eg getFuncName),
65// whereas functions taking address as args will deal with function
66// descriptors (eg os::dll_address_to_library_name).
67typedef unsigned int* codeptr_t;
68
69// helper function - given a program counter, tries to locate the traceback table and
70// returns info from it (like, most importantly, function name, displacement of the
71// pc inside the function, and the traceback table itself.
72#ifdef __cplusplus
73extern "C"
74#endif
75int getFuncName(
76      codeptr_t pc,                    // [in] program counter
77      char* p_name, size_t namelen,    // [out] optional: user provided buffer for the function name
78      int* p_displacement,             // [out] optional: displacement
79      const struct tbtable** p_tb,     // [out] optional: ptr to traceback table to get further information
80      char* p_errmsg, size_t errmsglen // [out] optional: user provided buffer for error messages
81    );
82