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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) 2000-2012 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 // It's an abstract type.
34 typedef
35    struct _ExeContext
36    ExeContext;
37 
38 // Resolution type used to decide how closely to compare two errors for
39 // equality.
40 typedef
41    enum { Vg_LowRes, Vg_MedRes, Vg_HighRes }
42    VgRes;
43 
44 // Take a snapshot of the client's stack.  Search our collection of
45 // ExeContexts to see if we already have it, and if not, allocate a
46 // new one.  Either way, return a pointer to the context.  Context size
47 // controlled by --num-callers option.
48 //
49 // This should only be used for long-lived stack traces.  If you want a
50 // short-lived stack trace, use VG_(get_StackTrace)().
51 //
52 // If called from generated code, use VG_(get_running_tid)() to get the
53 // current ThreadId.  If called from non-generated code, the current
54 // ThreadId should be passed in by the core.  The initial IP value to
55 // use is adjusted by first_ip_delta before the stack is unwound.
56 // A safe value to pass is zero.
57 //
58 // See comments in pub_tool_stacktrace.h for precise definition of
59 // the meaning of the code addresses in the returned ExeContext.
60 extern
61 ExeContext* VG_(record_ExeContext) ( ThreadId tid, Word first_ip_delta );
62 
63 // Trivial version of VG_(record_ExeContext), which just records the
64 // thread's current program counter but does not do any stack
65 // unwinding.  This is useful in some rare cases when we suspect the
66 // stack might be outside mapped storage, and so unwinding
67 // might cause a segfault.  In this case we can at least safely
68 // produce a one-element stack trace, which is better than nothing.
69 extern
70 ExeContext* VG_(record_depth_1_ExeContext)(ThreadId tid, Word first_ip_delta);
71 
72 // Apply a function to every element in the ExeContext.  The parameter 'n'
73 // gives the index of the passed ip.  Doesn't go below main() unless
74 // --show-below-main=yes is set.
75 extern void VG_(apply_ExeContext)( void(*action)(UInt n, Addr ip),
76                                    ExeContext* ec, UInt n_ips );
77 
78 // Compare two ExeContexts.  Number of callers considered depends on `res':
79 //   Vg_LowRes:  2
80 //   Vg_MedRes:  4
81 //   Vg_HighRes: all
82 extern Bool VG_(eq_ExeContext) ( VgRes res, ExeContext* e1, ExeContext* e2 );
83 
84 // Print an ExeContext.
85 extern void VG_(pp_ExeContext) ( ExeContext* ec );
86 
87 // Get the 32-bit unique reference number for this ExeContext
88 // (the "ExeContext Unique").  Guaranteed to be nonzero and to be a
89 // multiple of four (iow, the lowest two bits are guaranteed to
90 // be zero, so that callers can store other information there.
91 extern UInt VG_(get_ECU_from_ExeContext)( ExeContext* e );
92 
93 // How many entries (frames) in this ExeContext?
94 extern Int VG_(get_ExeContext_n_ips)( ExeContext* e );
95 
96 // Find the ExeContext that has the given ECU, if any.
97 // NOTE: very slow.  Do not call often.
98 extern ExeContext* VG_(get_ExeContext_from_ECU)( UInt uniq );
99 
100 // Make an ExeContext containing just 'a', and nothing else
101 ExeContext* VG_(make_depth_1_ExeContext_from_Addr)( Addr a );
102 
103 // Is this a plausible-looking ECU ?  Catches some obvious stupid
104 // cases, but does not guarantee that the ECU is really valid, that
105 // is, has an associated ExeContext.
VG_(is_plausible_ECU)106 static inline Bool VG_(is_plausible_ECU)( UInt ecu ) {
107    return (ecu > 0) && ((ecu & 3) == 0);
108 }
109 
110 // Make an ExeContext containing exactly the specified stack frames.
111 ExeContext* VG_(make_ExeContext_from_StackTrace)( Addr* ips, UInt n_ips );
112 
113 #endif   // __PUB_TOOL_EXECONTEXT_H
114 
115 /*--------------------------------------------------------------------*/
116 /*--- end                                                          ---*/
117 /*--------------------------------------------------------------------*/
118