1 //===-- StackID.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/Target/StackID.h"
11 #include "lldb/Symbol/Block.h"
12 #include "lldb/Symbol/Symbol.h"
13 #include "lldb/Symbol/SymbolContext.h"
14 #include "lldb/Utility/Stream.h"
15 
16 using namespace lldb_private;
17 
18 void StackID::Dump(Stream *s) {
19   s->Printf("StackID (pc = 0x%16.16" PRIx64 ", cfa = 0x%16.16" PRIx64
20             ", symbol_scope = %p",
21             m_pc, m_cfa, static_cast<void *>(m_symbol_scope));
22   if (m_symbol_scope) {
23     SymbolContext sc;
24 
25     m_symbol_scope->CalculateSymbolContext(&sc);
26     if (sc.block)
27       s->Printf(" (Block {0x%8.8" PRIx64 "})", sc.block->GetID());
28     else if (sc.symbol)
29       s->Printf(" (Symbol{0x%8.8x})", sc.symbol->GetID());
30   }
31   s->PutCString(") ");
32 }
33 
34 bool lldb_private::operator==(const StackID &lhs, const StackID &rhs) {
35   if (lhs.GetCallFrameAddress() != rhs.GetCallFrameAddress())
36     return false;
37 
38   SymbolContextScope *lhs_scope = lhs.GetSymbolContextScope();
39   SymbolContextScope *rhs_scope = rhs.GetSymbolContextScope();
40 
41   // Only compare the PC values if both symbol context scopes are nullptr
42   if (lhs_scope == nullptr && rhs_scope == nullptr)
43     return lhs.GetPC() == rhs.GetPC();
44 
45   return lhs_scope == rhs_scope;
46 }
47 
48 bool lldb_private::operator!=(const StackID &lhs, const StackID &rhs) {
49   if (lhs.GetCallFrameAddress() != rhs.GetCallFrameAddress())
50     return true;
51 
52   SymbolContextScope *lhs_scope = lhs.GetSymbolContextScope();
53   SymbolContextScope *rhs_scope = rhs.GetSymbolContextScope();
54 
55   if (lhs_scope == nullptr && rhs_scope == nullptr)
56     return lhs.GetPC() != rhs.GetPC();
57 
58   return lhs_scope != rhs_scope;
59 }
60 
61 bool lldb_private::operator<(const StackID &lhs, const StackID &rhs) {
62   const lldb::addr_t lhs_cfa = lhs.GetCallFrameAddress();
63   const lldb::addr_t rhs_cfa = rhs.GetCallFrameAddress();
64 
65   // FIXME: We are assuming that the stacks grow downward in memory.  That's not
66   // necessary, but true on
67   // all the machines we care about at present.  If this changes, we'll have to
68   // deal with that.  The ABI is the agent who knows this ordering, but the
69   // StackID has no access to the ABI. The most straightforward way to handle
70   // this is to add a "m_grows_downward" bool to the StackID, and set it in the
71   // constructor. But I'm not going to waste a bool per StackID on this till we
72   // need it.
73 
74   if (lhs_cfa != rhs_cfa)
75     return lhs_cfa < rhs_cfa;
76 
77   SymbolContextScope *lhs_scope = lhs.GetSymbolContextScope();
78   SymbolContextScope *rhs_scope = rhs.GetSymbolContextScope();
79 
80   if (lhs_scope != nullptr && rhs_scope != nullptr) {
81     // Same exact scope, lhs is not less than (younger than rhs)
82     if (lhs_scope == rhs_scope)
83       return false;
84 
85     SymbolContext lhs_sc;
86     SymbolContext rhs_sc;
87     lhs_scope->CalculateSymbolContext(&lhs_sc);
88     rhs_scope->CalculateSymbolContext(&rhs_sc);
89 
90     // Items with the same function can only be compared
91     if (lhs_sc.function == rhs_sc.function && lhs_sc.function != nullptr &&
92         lhs_sc.block != nullptr && rhs_sc.function != nullptr &&
93         rhs_sc.block != nullptr) {
94       return rhs_sc.block->Contains(lhs_sc.block);
95     }
96   }
97   return false;
98 }
99