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) 2000-2017 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.
36 typedef
37 struct _ExeContext
38 ExeContext;
39
40 // Resolution type used to decide how closely to compare two errors for
41 // equality.
42 typedef
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.
62 extern
63 ExeContext* 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.
71 extern
72 ExeContext* 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.
77 extern 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
84 extern Bool VG_(eq_ExeContext) ( VgRes res, const ExeContext* e1,
85 const ExeContext* e2 );
86
87 // Print an ExeContext.
88 extern 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.
94 extern UInt VG_(get_ECU_from_ExeContext)( const ExeContext* e );
95
96 // How many entries (frames) in this ExeContext?
97 extern 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.
101 extern ExeContext* VG_(get_ExeContext_from_ECU)( UInt uniq );
102
103 // Make an ExeContext containing just 'a', and nothing else
104 ExeContext* 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.
VG_(is_plausible_ECU)109 static 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.
114 ExeContext* 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).
118 extern
119 ExeContext* VG_(null_ExeContext) (void);
120
121 #endif // __PUB_TOOL_EXECONTEXT_H
122
123 /*--------------------------------------------------------------------*/
124 /*--- end ---*/
125 /*--------------------------------------------------------------------*/
126