1 //===-- BreakpointResolverFileLine.cpp --------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Breakpoint/BreakpointResolverFileLine.h"
11 
12 // C Includes
13 // C++ Includes
14 // Other libraries and framework includes
15 // Project includes
16 #include "lldb/Breakpoint/BreakpointLocation.h"
17 #include "lldb/Core/Module.h"
18 #include "lldb/Symbol/CompileUnit.h"
19 #include "lldb/Symbol/Function.h"
20 #include "lldb/Utility/Log.h"
21 #include "lldb/Utility/StreamString.h"
22 
23 using namespace lldb;
24 using namespace lldb_private;
25 
26 //----------------------------------------------------------------------
27 // BreakpointResolverFileLine:
28 //----------------------------------------------------------------------
29 BreakpointResolverFileLine::BreakpointResolverFileLine(
30     Breakpoint *bkpt, const FileSpec &file_spec, uint32_t line_no,
31     lldb::addr_t offset, bool check_inlines, bool skip_prologue,
32     bool exact_match)
33     : BreakpointResolver(bkpt, BreakpointResolver::FileLineResolver, offset),
34       m_file_spec(file_spec), m_line_number(line_no), m_inlines(check_inlines),
35       m_skip_prologue(skip_prologue), m_exact_match(exact_match) {}
36 
37 BreakpointResolverFileLine::~BreakpointResolverFileLine() {}
38 
39 BreakpointResolver *BreakpointResolverFileLine::CreateFromStructuredData(
40     Breakpoint *bkpt, const StructuredData::Dictionary &options_dict,
41     Status &error) {
42   llvm::StringRef filename;
43   uint32_t line_no;
44   bool check_inlines;
45   bool skip_prologue;
46   bool exact_match;
47   bool success;
48 
49   lldb::addr_t offset = 0;
50 
51   success = options_dict.GetValueForKeyAsString(GetKey(OptionNames::FileName),
52                                                 filename);
53   if (!success) {
54     error.SetErrorString("BRFL::CFSD: Couldn't find filename entry.");
55     return nullptr;
56   }
57 
58   success = options_dict.GetValueForKeyAsInteger(
59       GetKey(OptionNames::LineNumber), line_no);
60   if (!success) {
61     error.SetErrorString("BRFL::CFSD: Couldn't find line number entry.");
62     return nullptr;
63   }
64 
65   success = options_dict.GetValueForKeyAsBoolean(GetKey(OptionNames::Inlines),
66                                                  check_inlines);
67   if (!success) {
68     error.SetErrorString("BRFL::CFSD: Couldn't find check inlines entry.");
69     return nullptr;
70   }
71 
72   success = options_dict.GetValueForKeyAsBoolean(
73       GetKey(OptionNames::SkipPrologue), skip_prologue);
74   if (!success) {
75     error.SetErrorString("BRFL::CFSD: Couldn't find skip prologue entry.");
76     return nullptr;
77   }
78 
79   success = options_dict.GetValueForKeyAsBoolean(
80       GetKey(OptionNames::ExactMatch), exact_match);
81   if (!success) {
82     error.SetErrorString("BRFL::CFSD: Couldn't find exact match entry.");
83     return nullptr;
84   }
85 
86   FileSpec file_spec(filename, false);
87 
88   return new BreakpointResolverFileLine(bkpt, file_spec, line_no, offset,
89                                         check_inlines, skip_prologue,
90                                         exact_match);
91 }
92 
93 StructuredData::ObjectSP
94 BreakpointResolverFileLine::SerializeToStructuredData() {
95   StructuredData::DictionarySP options_dict_sp(
96       new StructuredData::Dictionary());
97 
98   options_dict_sp->AddStringItem(GetKey(OptionNames::FileName),
99                                  m_file_spec.GetPath());
100   options_dict_sp->AddIntegerItem(GetKey(OptionNames::LineNumber),
101                                   m_line_number);
102   options_dict_sp->AddBooleanItem(GetKey(OptionNames::Inlines), m_inlines);
103   options_dict_sp->AddBooleanItem(GetKey(OptionNames::SkipPrologue),
104                                   m_skip_prologue);
105   options_dict_sp->AddBooleanItem(GetKey(OptionNames::ExactMatch),
106                                   m_exact_match);
107 
108   return WrapOptionsDict(options_dict_sp);
109 }
110 
111 // Filter the symbol context list to remove contexts where the line number was
112 // moved into a new function. We do this conservatively, so if e.g. we cannot
113 // resolve the function in the context (which can happen in case of
114 // line-table-only debug info), we leave the context as is. The trickiest part
115 // here is handling inlined functions -- in this case we need to make sure we
116 // look at the declaration line of the inlined function, NOT the function it was
117 // inlined into.
118 void BreakpointResolverFileLine::FilterContexts(SymbolContextList &sc_list) {
119   if (m_exact_match)
120     return; // Nothing to do. Contexts are precise.
121 
122   Log * log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_BREAKPOINTS);
123   for(uint32_t i = 0; i < sc_list.GetSize(); ++i) {
124     SymbolContext sc;
125     sc_list.GetContextAtIndex(i, sc);
126     if (! sc.block)
127       continue;
128 
129     FileSpec file;
130     uint32_t line;
131     const Block *inline_block = sc.block->GetContainingInlinedBlock();
132     if (inline_block) {
133       const Declaration &inline_declaration = inline_block->GetInlinedFunctionInfo()->GetDeclaration();
134       if (!inline_declaration.IsValid())
135         continue;
136       file = inline_declaration.GetFile();
137       line = inline_declaration.GetLine();
138     } else if (sc.function)
139       sc.function->GetStartLineSourceInfo(file, line);
140     else
141       continue;
142 
143     if (file != sc.line_entry.file) {
144       LLDB_LOG(log, "unexpected symbol context file {0}", sc.line_entry.file);
145       continue;
146     }
147 
148     // Compare the requested line number with the line of the function
149     // declaration. In case of a function declared as:
150     //
151     // int
152     // foo()
153     // {
154     //   ...
155     //
156     // the compiler will set the declaration line to the "foo" line, which is
157     // the reason why we have -1 here. This can fail in case of two inline
158     // functions defined back-to-back:
159     //
160     // inline int foo1() { ... }
161     // inline int foo2() { ... }
162     //
163     // but that's the best we can do for now.
164     const int decl_line_is_too_late_fudge = 1;
165     if (m_line_number < line - decl_line_is_too_late_fudge) {
166       LLDB_LOG(log, "removing symbol context at {0}:{1}", file, line);
167       sc_list.RemoveContextAtIndex(i);
168       --i;
169     }
170   }
171 }
172 
173 Searcher::CallbackReturn
174 BreakpointResolverFileLine::SearchCallback(SearchFilter &filter,
175                                            SymbolContext &context,
176                                            Address *addr, bool containing) {
177   SymbolContextList sc_list;
178 
179   assert(m_breakpoint != NULL);
180 
181   // There is a tricky bit here.  You can have two compilation units that
182   // #include the same file, and in one of them the function at m_line_number is
183   // used (and so code and a line entry for it is generated) but in the other it
184   // isn't.  If we considered the CU's independently, then in the second
185   // inclusion, we'd move the breakpoint to the next function that actually
186   // generated code in the header file.  That would end up being confusing.  So
187   // instead, we do the CU iterations by hand here, then scan through the
188   // complete list of matches, and figure out the closest line number match, and
189   // only set breakpoints on that match.
190 
191   // Note also that if file_spec only had a file name and not a directory, there
192   // may be many different file spec's in the resultant list.  The closest line
193   // match for one will not be right for some totally different file.  So we go
194   // through the match list and pull out the sets that have the same file spec
195   // in their line_entry and treat each set separately.
196 
197   const size_t num_comp_units = context.module_sp->GetNumCompileUnits();
198   for (size_t i = 0; i < num_comp_units; i++) {
199     CompUnitSP cu_sp(context.module_sp->GetCompileUnitAtIndex(i));
200     if (cu_sp) {
201       if (filter.CompUnitPasses(*cu_sp))
202         cu_sp->ResolveSymbolContext(m_file_spec, m_line_number, m_inlines,
203                                     m_exact_match, eSymbolContextEverything,
204                                     sc_list);
205     }
206   }
207 
208   FilterContexts(sc_list);
209 
210   StreamString s;
211   s.Printf("for %s:%d ", m_file_spec.GetFilename().AsCString("<Unknown>"),
212            m_line_number);
213 
214   SetSCMatchesByLine(filter, sc_list, m_skip_prologue, s.GetString());
215 
216   return Searcher::eCallbackReturnContinue;
217 }
218 
219 Searcher::Depth BreakpointResolverFileLine::GetDepth() {
220   return Searcher::eDepthModule;
221 }
222 
223 void BreakpointResolverFileLine::GetDescription(Stream *s) {
224   s->Printf("file = '%s', line = %u, exact_match = %d",
225             m_file_spec.GetPath().c_str(), m_line_number, m_exact_match);
226 }
227 
228 void BreakpointResolverFileLine::Dump(Stream *s) const {}
229 
230 lldb::BreakpointResolverSP
231 BreakpointResolverFileLine::CopyForBreakpoint(Breakpoint &breakpoint) {
232   lldb::BreakpointResolverSP ret_sp(new BreakpointResolverFileLine(
233       &breakpoint, m_file_spec, m_line_number, m_offset, m_inlines,
234       m_skip_prologue, m_exact_match));
235 
236   return ret_sp;
237 }
238