1/*--------------------------------------------------------------------*/
2/*--- ExeContexts: long-lived stack traces.  pub_tool_execontext.h ---*/
3/*--------------------------------------------------------------------*/
4
5/*
6   This file is part of Valgrind, a dynamic binary instrumentation
7   framework.
8
9   Copyright (C) 2000-2013 Julian Seward
10      jseward@acm.org
11
12   This program is free software; you can redistribute it and/or
13   modify it under the terms of the GNU General Public License as
14   published by the Free Software Foundation; either version 2 of the
15   License, or (at your option) any later version.
16
17   This program is distributed in the hope that it will be useful, but
18   WITHOUT ANY WARRANTY; without even the implied warranty of
19   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20   General Public License for more details.
21
22   You should have received a copy of the GNU General Public License
23   along with this program; if not, write to the Free Software
24   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
25   02111-1307, USA.
26
27   The GNU General Public License is contained in the file COPYING.
28*/
29
30#ifndef __PUB_TOOL_EXECONTEXT_H
31#define __PUB_TOOL_EXECONTEXT_H
32
33#include "pub_tool_basics.h"   // ThreadID
34
35// It's an abstract type.
36typedef
37   struct _ExeContext
38   ExeContext;
39
40// Resolution type used to decide how closely to compare two errors for
41// equality.
42typedef
43   enum { Vg_LowRes, Vg_MedRes, Vg_HighRes }
44   VgRes;
45
46// Take a snapshot of the client's stack.  Search our collection of
47// ExeContexts to see if we already have it, and if not, allocate a
48// new one.  Either way, return a pointer to the context.  Context size
49// controlled by --num-callers option.
50//
51// This should only be used for long-lived stack traces.  If you want a
52// short-lived stack trace, use VG_(get_StackTrace)().
53//
54// If called from generated code, use VG_(get_running_tid)() to get the
55// current ThreadId.  If called from non-generated code, the current
56// ThreadId should be passed in by the core.  The initial IP value to
57// use is adjusted by first_ip_delta before the stack is unwound.
58// A safe value to pass is zero.
59//
60// See comments in pub_tool_stacktrace.h for precise definition of
61// the meaning of the code addresses in the returned ExeContext.
62extern
63ExeContext* VG_(record_ExeContext) ( ThreadId tid, Word first_ip_delta );
64
65// Trivial version of VG_(record_ExeContext), which just records the
66// thread's current program counter but does not do any stack
67// unwinding.  This is useful in some rare cases when we suspect the
68// stack might be outside mapped storage, and so unwinding
69// might cause a segfault.  In this case we can at least safely
70// produce a one-element stack trace, which is better than nothing.
71extern
72ExeContext* VG_(record_depth_1_ExeContext)(ThreadId tid, Word first_ip_delta);
73
74// Apply a function to every element in the ExeContext.  The parameter 'n'
75// gives the index of the passed ip.  Doesn't go below main() unless
76// --show-below-main=yes is set.
77extern void VG_(apply_ExeContext)( void(*action)(UInt n, Addr ip),
78                                   ExeContext* ec, UInt n_ips );
79
80// Compare two ExeContexts.  Number of callers considered depends on `res':
81//   Vg_LowRes:  2
82//   Vg_MedRes:  4
83//   Vg_HighRes: all
84extern Bool VG_(eq_ExeContext) ( VgRes res, const ExeContext* e1,
85                                 const ExeContext* e2 );
86
87// Print an ExeContext.
88extern void VG_(pp_ExeContext) ( ExeContext* ec );
89
90// Get the 32-bit unique reference number for this ExeContext
91// (the "ExeContext Unique").  Guaranteed to be nonzero and to be a
92// multiple of four (iow, the lowest two bits are guaranteed to
93// be zero, so that callers can store other information there.
94extern UInt VG_(get_ECU_from_ExeContext)( const ExeContext* e );
95
96// How many entries (frames) in this ExeContext?
97extern Int VG_(get_ExeContext_n_ips)( const ExeContext* e );
98
99// Find the ExeContext that has the given ECU, if any.
100// NOTE: very slow.  Do not call often.
101extern ExeContext* VG_(get_ExeContext_from_ECU)( UInt uniq );
102
103// Make an ExeContext containing just 'a', and nothing else
104ExeContext* VG_(make_depth_1_ExeContext_from_Addr)( Addr a );
105
106// Is this a plausible-looking ECU ?  Catches some obvious stupid
107// cases, but does not guarantee that the ECU is really valid, that
108// is, has an associated ExeContext.
109static inline Bool VG_(is_plausible_ECU)( UInt ecu ) {
110   return (ecu > 0) && ((ecu & 3) == 0);
111}
112
113// Make an ExeContext containing exactly the specified stack frames.
114ExeContext* VG_(make_ExeContext_from_StackTrace)( const Addr* ips, UInt n_ips );
115
116// Returns the "null" exe context. The null execontext is an artificial
117// exe context, with a stack trace made of one Addr (the NULL address).
118extern
119ExeContext* VG_(null_ExeContext) (void);
120
121#endif   // __PUB_TOOL_EXECONTEXT_H
122
123/*--------------------------------------------------------------------*/
124/*--- end                                                          ---*/
125/*--------------------------------------------------------------------*/
126