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