1 #include "lldb/Core/Module.h"
2 #include "lldb/Symbol/Function.h"
3 #include "lldb/Symbol/SymbolContext.h"
4 #include "lldb/Target/Process.h"
5 #include "lldb/Target/StackFrameList.h"
6 #include "lldb/Target/Target.h"
7 #include "lldb/Target/Thread.h"
8 
9 #include "lldb/Utility/Log.h"
10 #include "lldb/Utility/Logging.h"
11 
12 #include "lldb/Target/AssertFrameRecognizer.h"
13 
14 using namespace llvm;
15 using namespace lldb;
16 using namespace lldb_private;
17 
18 namespace lldb_private {
19 
20 /// Stores a function module spec, symbol name and possibly an alternate symbol
21 /// name.
22 struct SymbolLocation {
23   FileSpec module_spec;
24   std::vector<ConstString> symbols;
25 };
26 
27 /// Fetches the abort frame location depending on the current platform.
28 ///
29 /// \param[in] os
30 ///    The target's os type.
31 /// \param[in,out] location
32 ///    The struct that will contain the abort module spec and symbol names.
33 /// \return
34 ///    \b true, if the platform is supported
35 ///    \b false, otherwise.
36 bool GetAbortLocation(llvm::Triple::OSType os, SymbolLocation &location) {
37   switch (os) {
38   case llvm::Triple::Darwin:
39   case llvm::Triple::MacOSX:
40     location.module_spec = FileSpec("libsystem_kernel.dylib");
41     location.symbols.push_back(ConstString("__pthread_kill"));
42     break;
43   case llvm::Triple::Linux:
44     location.module_spec = FileSpec("libc.so.6");
45     location.symbols.push_back(ConstString("raise"));
46     location.symbols.push_back(ConstString("__GI_raise"));
47     location.symbols.push_back(ConstString("gsignal"));
48     break;
49   default:
50     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND));
51     LLDB_LOG(log, "AssertFrameRecognizer::GetAbortLocation Unsupported OS");
52     return false;
53   }
54 
55   return true;
56 }
57 
58 /// Fetches the assert frame location depending on the current platform.
59 ///
60 /// \param[in] os
61 ///    The target's os type.
62 /// \param[in,out] location
63 ///    The struct that will contain the assert module spec and symbol names.
64 /// \return
65 ///    \b true, if the platform is supported
66 ///    \b false, otherwise.
67 bool GetAssertLocation(llvm::Triple::OSType os, SymbolLocation &location) {
68   switch (os) {
69   case llvm::Triple::Darwin:
70   case llvm::Triple::MacOSX:
71     location.module_spec = FileSpec("libsystem_c.dylib");
72     location.symbols.push_back(ConstString("__assert_rtn"));
73     break;
74   case llvm::Triple::Linux:
75     location.module_spec = FileSpec("libc.so.6");
76     location.symbols.push_back(ConstString("__assert_fail"));
77     location.symbols.push_back(ConstString("__GI___assert_fail"));
78     break;
79   default:
80     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND));
81     LLDB_LOG(log, "AssertFrameRecognizer::GetAssertLocation Unsupported OS");
82     return false;
83   }
84 
85   return true;
86 }
87 
88 void RegisterAssertFrameRecognizer(Process *process) {
89   static llvm::once_flag g_once_flag;
90   llvm::call_once(g_once_flag, [process]() {
91     Target &target = process->GetTarget();
92     llvm::Triple::OSType os = target.GetArchitecture().GetTriple().getOS();
93     SymbolLocation location;
94 
95     if (!GetAbortLocation(os, location))
96       return;
97 
98     StackFrameRecognizerManager::AddRecognizer(
99         StackFrameRecognizerSP(new AssertFrameRecognizer()),
100         location.module_spec.GetFilename(), location.symbols,
101         /*first_instruction_only*/ false);
102   });
103 }
104 
105 } // namespace lldb_private
106 
107 lldb::RecognizedStackFrameSP
108 AssertFrameRecognizer::RecognizeFrame(lldb::StackFrameSP frame_sp) {
109   ThreadSP thread_sp = frame_sp->GetThread();
110   ProcessSP process_sp = thread_sp->GetProcess();
111   Target &target = process_sp->GetTarget();
112   llvm::Triple::OSType os = target.GetArchitecture().GetTriple().getOS();
113   SymbolLocation location;
114 
115   if (!GetAssertLocation(os, location))
116     return RecognizedStackFrameSP();
117 
118   const uint32_t frames_to_fetch = 5;
119   const uint32_t last_frame_index = frames_to_fetch - 1;
120   StackFrameSP prev_frame_sp = nullptr;
121 
122   // Fetch most relevant frame
123   for (uint32_t frame_index = 0; frame_index < frames_to_fetch; frame_index++) {
124     prev_frame_sp = thread_sp->GetStackFrameAtIndex(frame_index);
125 
126     if (!prev_frame_sp) {
127       Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND));
128       LLDB_LOG(log, "Abort Recognizer: Hit unwinding bound ({1} frames)!",
129                frames_to_fetch);
130       break;
131     }
132 
133     SymbolContext sym_ctx =
134         prev_frame_sp->GetSymbolContext(eSymbolContextEverything);
135 
136     if (!sym_ctx.module_sp->GetFileSpec().FileEquals(location.module_spec))
137       continue;
138 
139     ConstString func_name = sym_ctx.GetFunctionName();
140 
141     if (llvm::is_contained(location.symbols, func_name)) {
142       // We go a frame beyond the assert location because the most relevant
143       // frame for the user is the one in which the assert function was called.
144       // If the assert location is the last frame fetched, then it is set as
145       // the most relevant frame.
146 
147       StackFrameSP most_relevant_frame_sp = thread_sp->GetStackFrameAtIndex(
148           std::min(frame_index + 1, last_frame_index));
149 
150       // Pass assert location to AbortRecognizedStackFrame to set as most
151       // relevant frame.
152       return lldb::RecognizedStackFrameSP(
153           new AssertRecognizedStackFrame(most_relevant_frame_sp));
154     }
155   }
156 
157   return RecognizedStackFrameSP();
158 }
159 
160 AssertRecognizedStackFrame::AssertRecognizedStackFrame(
161     StackFrameSP most_relevant_frame_sp)
162     : m_most_relevant_frame(most_relevant_frame_sp) {
163   m_stop_desc = "hit program assert";
164 }
165 
166 lldb::StackFrameSP AssertRecognizedStackFrame::GetMostRelevantFrame() {
167   return m_most_relevant_frame;
168 }
169