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   // The symbols are regular expressions. In such case all symbols are matched
27   // with their trailing @VER symbol version stripped.
28   bool symbols_are_regex = false;
29 };
30 
31 /// Fetches the abort frame location depending on the current platform.
32 ///
33 /// \param[in] os
34 ///    The target's os type.
35 /// \param[in,out] location
36 ///    The struct that will contain the abort module spec and symbol names.
37 /// \return
38 ///    \b true, if the platform is supported
39 ///    \b false, otherwise.
40 bool GetAbortLocation(llvm::Triple::OSType os, SymbolLocation &location) {
41   switch (os) {
42   case llvm::Triple::Darwin:
43   case llvm::Triple::MacOSX:
44     location.module_spec = FileSpec("libsystem_kernel.dylib");
45     location.symbols.push_back(ConstString("__pthread_kill"));
46     break;
47   case llvm::Triple::Linux:
48     location.module_spec = FileSpec("libc.so.6");
49     location.symbols.push_back(ConstString("raise"));
50     location.symbols.push_back(ConstString("__GI_raise"));
51     location.symbols.push_back(ConstString("gsignal"));
52     location.symbols.push_back(ConstString("pthread_kill"));
53     location.symbols_are_regex = true;
54     break;
55   default:
56     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND));
57     LLDB_LOG(log, "AssertFrameRecognizer::GetAbortLocation Unsupported OS");
58     return false;
59   }
60 
61   return true;
62 }
63 
64 /// Fetches the assert frame location depending on the current platform.
65 ///
66 /// \param[in] os
67 ///    The target's os type.
68 /// \param[in,out] location
69 ///    The struct that will contain the assert module spec and symbol names.
70 /// \return
71 ///    \b true, if the platform is supported
72 ///    \b false, otherwise.
73 bool GetAssertLocation(llvm::Triple::OSType os, SymbolLocation &location) {
74   switch (os) {
75   case llvm::Triple::Darwin:
76   case llvm::Triple::MacOSX:
77     location.module_spec = FileSpec("libsystem_c.dylib");
78     location.symbols.push_back(ConstString("__assert_rtn"));
79     break;
80   case llvm::Triple::Linux:
81     location.module_spec = FileSpec("libc.so.6");
82     location.symbols.push_back(ConstString("__assert_fail"));
83     location.symbols.push_back(ConstString("__GI___assert_fail"));
84     break;
85   default:
86     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND));
87     LLDB_LOG(log, "AssertFrameRecognizer::GetAssertLocation Unsupported OS");
88     return false;
89   }
90 
91   return true;
92 }
93 
94 void RegisterAssertFrameRecognizer(Process *process) {
95   Target &target = process->GetTarget();
96   llvm::Triple::OSType os = target.GetArchitecture().GetTriple().getOS();
97   SymbolLocation location;
98 
99   if (!GetAbortLocation(os, location))
100     return;
101 
102   if (!location.symbols_are_regex) {
103     target.GetFrameRecognizerManager().AddRecognizer(
104         std::make_shared<AssertFrameRecognizer>(),
105         location.module_spec.GetFilename(), location.symbols,
106         /*first_instruction_only*/ false);
107     return;
108   }
109   std::string module_re = "^";
110   for (char c : location.module_spec.GetFilename().GetStringRef()) {
111     if (c == '.')
112       module_re += '\\';
113     module_re += c;
114   }
115   module_re += '$';
116   std::string symbol_re = "^(";
117   for (auto it = location.symbols.cbegin(); it != location.symbols.cend();
118        ++it) {
119     if (it != location.symbols.cbegin())
120       symbol_re += '|';
121     symbol_re += it->GetStringRef();
122   }
123   // Strip the trailing @VER symbol version.
124   symbol_re += ")(@.*)?$";
125   target.GetFrameRecognizerManager().AddRecognizer(
126       std::make_shared<AssertFrameRecognizer>(),
127       std::make_shared<RegularExpression>(std::move(module_re)),
128       std::make_shared<RegularExpression>(std::move(symbol_re)),
129       /*first_instruction_only*/ false);
130 }
131 
132 } // namespace lldb_private
133 
134 lldb::RecognizedStackFrameSP
135 AssertFrameRecognizer::RecognizeFrame(lldb::StackFrameSP frame_sp) {
136   ThreadSP thread_sp = frame_sp->GetThread();
137   ProcessSP process_sp = thread_sp->GetProcess();
138   Target &target = process_sp->GetTarget();
139   llvm::Triple::OSType os = target.GetArchitecture().GetTriple().getOS();
140   SymbolLocation location;
141 
142   if (!GetAssertLocation(os, location))
143     return RecognizedStackFrameSP();
144 
145   const uint32_t frames_to_fetch = 6;
146   const uint32_t last_frame_index = frames_to_fetch - 1;
147   StackFrameSP prev_frame_sp = nullptr;
148 
149   // Fetch most relevant frame
150   for (uint32_t frame_index = 0; frame_index < frames_to_fetch; frame_index++) {
151     prev_frame_sp = thread_sp->GetStackFrameAtIndex(frame_index);
152 
153     if (!prev_frame_sp) {
154       Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND));
155       LLDB_LOG(log, "Abort Recognizer: Hit unwinding bound ({1} frames)!",
156                frames_to_fetch);
157       break;
158     }
159 
160     SymbolContext sym_ctx =
161         prev_frame_sp->GetSymbolContext(eSymbolContextEverything);
162 
163     if (!sym_ctx.module_sp ||
164         !sym_ctx.module_sp->GetFileSpec().FileEquals(location.module_spec))
165       continue;
166 
167     ConstString func_name = sym_ctx.GetFunctionName();
168 
169     if (llvm::is_contained(location.symbols, func_name)) {
170       // We go a frame beyond the assert location because the most relevant
171       // frame for the user is the one in which the assert function was called.
172       // If the assert location is the last frame fetched, then it is set as
173       // the most relevant frame.
174 
175       StackFrameSP most_relevant_frame_sp = thread_sp->GetStackFrameAtIndex(
176           std::min(frame_index + 1, last_frame_index));
177 
178       // Pass assert location to AbortRecognizedStackFrame to set as most
179       // relevant frame.
180       return lldb::RecognizedStackFrameSP(
181           new AssertRecognizedStackFrame(most_relevant_frame_sp));
182     }
183   }
184 
185   return RecognizedStackFrameSP();
186 }
187 
188 AssertRecognizedStackFrame::AssertRecognizedStackFrame(
189     StackFrameSP most_relevant_frame_sp)
190     : m_most_relevant_frame(most_relevant_frame_sp) {
191   m_stop_desc = "hit program assert";
192 }
193 
194 lldb::StackFrameSP AssertRecognizedStackFrame::GetMostRelevantFrame() {
195   return m_most_relevant_frame;
196 }
197