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   Target &target = process->GetTarget();
90   llvm::Triple::OSType os = target.GetArchitecture().GetTriple().getOS();
91   SymbolLocation location;
92 
93   if (!GetAbortLocation(os, location))
94     return;
95 
96   target.GetFrameRecognizerManager().AddRecognizer(
97       StackFrameRecognizerSP(new AssertFrameRecognizer()),
98       location.module_spec.GetFilename(), location.symbols,
99       /*first_instruction_only*/ false);
100 }
101 
102 } // namespace lldb_private
103 
104 lldb::RecognizedStackFrameSP
105 AssertFrameRecognizer::RecognizeFrame(lldb::StackFrameSP frame_sp) {
106   ThreadSP thread_sp = frame_sp->GetThread();
107   ProcessSP process_sp = thread_sp->GetProcess();
108   Target &target = process_sp->GetTarget();
109   llvm::Triple::OSType os = target.GetArchitecture().GetTriple().getOS();
110   SymbolLocation location;
111 
112   if (!GetAssertLocation(os, location))
113     return RecognizedStackFrameSP();
114 
115   const uint32_t frames_to_fetch = 5;
116   const uint32_t last_frame_index = frames_to_fetch - 1;
117   StackFrameSP prev_frame_sp = nullptr;
118 
119   // Fetch most relevant frame
120   for (uint32_t frame_index = 0; frame_index < frames_to_fetch; frame_index++) {
121     prev_frame_sp = thread_sp->GetStackFrameAtIndex(frame_index);
122 
123     if (!prev_frame_sp) {
124       Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND));
125       LLDB_LOG(log, "Abort Recognizer: Hit unwinding bound ({1} frames)!",
126                frames_to_fetch);
127       break;
128     }
129 
130     SymbolContext sym_ctx =
131         prev_frame_sp->GetSymbolContext(eSymbolContextEverything);
132 
133     if (!sym_ctx.module_sp ||
134         !sym_ctx.module_sp->GetFileSpec().FileEquals(location.module_spec))
135       continue;
136 
137     ConstString func_name = sym_ctx.GetFunctionName();
138 
139     if (llvm::is_contained(location.symbols, func_name)) {
140       // We go a frame beyond the assert location because the most relevant
141       // frame for the user is the one in which the assert function was called.
142       // If the assert location is the last frame fetched, then it is set as
143       // the most relevant frame.
144 
145       StackFrameSP most_relevant_frame_sp = thread_sp->GetStackFrameAtIndex(
146           std::min(frame_index + 1, last_frame_index));
147 
148       // Pass assert location to AbortRecognizedStackFrame to set as most
149       // relevant frame.
150       return lldb::RecognizedStackFrameSP(
151           new AssertRecognizedStackFrame(most_relevant_frame_sp));
152     }
153   }
154 
155   return RecognizedStackFrameSP();
156 }
157 
158 AssertRecognizedStackFrame::AssertRecognizedStackFrame(
159     StackFrameSP most_relevant_frame_sp)
160     : m_most_relevant_frame(most_relevant_frame_sp) {
161   m_stop_desc = "hit program assert";
162 }
163 
164 lldb::StackFrameSP AssertRecognizedStackFrame::GetMostRelevantFrame() {
165   return m_most_relevant_frame;
166 }
167