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.
  22  *
  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 
  48 typedef 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
  57 extern "C"
  58 #endif
  59 int 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).
  67 typedef 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
  73 extern "C"
  74 #endif
  75 int 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     );