1 /*
2  *  Created by Phil on 27/12/2010.
3  *  Copyright 2010 Two Blue Cubes Ltd. All rights reserved.
4  *
5  *  Distributed under the Boost Software License, Version 1.0. (See accompanying
6  *  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7  *
8  */
9 
10 #include "catch_debugger.h"
11 #include "catch_errno_guard.h"
12 #include "catch_stream.h"
13 #include "catch_platform.h"
14 
15 #if defined(CATCH_PLATFORM_MAC) || defined(CATCH_PLATFORM_IPHONE)
16 
17 #  include <assert.h>
18 #  include <stdbool.h>
19 #  include <sys/types.h>
20 #  include <unistd.h>
21 #  include <cstddef>
22 #  include <ostream>
23 
24 #ifdef __apple_build_version__
25     // These headers will only compile with AppleClang (XCode)
26     // For other compilers (Clang, GCC, ... ) we need to exclude them
27 #  include <sys/sysctl.h>
28 #endif
29 
30     namespace Catch {
31         #ifdef __apple_build_version__
32         // The following function is taken directly from the following technical note:
33         // https://developer.apple.com/library/archive/qa/qa1361/_index.html
34 
35         // Returns true if the current process is being debugged (either
36         // running under the debugger or has a debugger attached post facto).
isDebuggerActive()37         bool isDebuggerActive(){
38             int                 mib[4];
39             struct kinfo_proc   info;
40             std::size_t         size;
41 
42             // Initialize the flags so that, if sysctl fails for some bizarre
43             // reason, we get a predictable result.
44 
45             info.kp_proc.p_flag = 0;
46 
47             // Initialize mib, which tells sysctl the info we want, in this case
48             // we're looking for information about a specific process ID.
49 
50             mib[0] = CTL_KERN;
51             mib[1] = KERN_PROC;
52             mib[2] = KERN_PROC_PID;
53             mib[3] = getpid();
54 
55             // Call sysctl.
56 
57             size = sizeof(info);
58             if( sysctl(mib, sizeof(mib) / sizeof(*mib), &info, &size, nullptr, 0) != 0 ) {
59                 Catch::cerr() << "\n** Call to sysctl failed - unable to determine if debugger is active **\n" << std::endl;
60                 return false;
61             }
62 
63             // We're being debugged if the P_TRACED flag is set.
64 
65             return ( (info.kp_proc.p_flag & P_TRACED) != 0 );
66         }
67         #else
68         bool isDebuggerActive() {
69             // We need to find another way to determine this for non-appleclang compilers on macOS
70             return false;
71         }
72         #endif
73     } // namespace Catch
74 
75 #elif defined(CATCH_PLATFORM_LINUX)
76     #include <fstream>
77     #include <string>
78 
79     namespace Catch{
80         // The standard POSIX way of detecting a debugger is to attempt to
81         // ptrace() the process, but this needs to be done from a child and not
82         // this process itself to still allow attaching to this process later
83         // if wanted, so is rather heavy. Under Linux we have the PID of the
84         // "debugger" (which doesn't need to be gdb, of course, it could also
85         // be strace, for example) in /proc/$PID/status, so just get it from
86         // there instead.
isDebuggerActive()87         bool isDebuggerActive(){
88             // Libstdc++ has a bug, where std::ifstream sets errno to 0
89             // This way our users can properly assert over errno values
90             ErrnoGuard guard;
91             std::ifstream in("/proc/self/status");
92             for( std::string line; std::getline(in, line); ) {
93                 static const int PREFIX_LEN = 11;
94                 if( line.compare(0, PREFIX_LEN, "TracerPid:\t") == 0 ) {
95                     // We're traced if the PID is not 0 and no other PID starts
96                     // with 0 digit, so it's enough to check for just a single
97                     // character.
98                     return line.length() > PREFIX_LEN && line[PREFIX_LEN] != '0';
99                 }
100             }
101 
102             return false;
103         }
104     } // namespace Catch
105 #elif defined(_MSC_VER)
106     extern "C" __declspec(dllimport) int __stdcall IsDebuggerPresent();
107     namespace Catch {
isDebuggerActive()108         bool isDebuggerActive() {
109             return IsDebuggerPresent() != 0;
110         }
111     }
112 #elif defined(__MINGW32__)
113     extern "C" __declspec(dllimport) int __stdcall IsDebuggerPresent();
114     namespace Catch {
isDebuggerActive()115         bool isDebuggerActive() {
116             return IsDebuggerPresent() != 0;
117         }
118     }
119 #else
120     namespace Catch {
isDebuggerActive()121        bool isDebuggerActive() { return false; }
122     }
123 #endif // Platform
124