StackID.cpp revision 314564 
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// C Includes
11// C++ Includes
12// Other libraries and framework includes
13// Project includes
14#include "lldb/Target/StackID.h"
15#include "lldb/Core/Stream.h"
16#include "lldb/Symbol/Block.h"
17#include "lldb/Symbol/Symbol.h"
18#include "lldb/Symbol/SymbolContext.h"
19
20using namespace lldb_private;
21
22void StackID::Dump(Stream *s) {
23  s->Printf("StackID (pc = 0x%16.16" PRIx64 ", cfa = 0x%16.16" PRIx64
24            ", symbol_scope = %p",
25            m_pc, m_cfa, static_cast<void *>(m_symbol_scope));
26  if (m_symbol_scope) {
27    SymbolContext sc;
28
29    m_symbol_scope->CalculateSymbolContext(&sc);
30    if (sc.block)
31      s->Printf(" (Block {0x%8.8" PRIx64 "})", sc.block->GetID());
32    else if (sc.symbol)
33      s->Printf(" (Symbol{0x%8.8x})", sc.symbol->GetID());
34  }
35  s->PutCString(") ");
36}
37
38bool lldb_private::operator==(const StackID &lhs, const StackID &rhs) {
39  if (lhs.GetCallFrameAddress() != rhs.GetCallFrameAddress())
40    return false;
41
42  SymbolContextScope *lhs_scope = lhs.GetSymbolContextScope();
43  SymbolContextScope *rhs_scope = rhs.GetSymbolContextScope();
44
45  // Only compare the PC values if both symbol context scopes are nullptr
46  if (lhs_scope == nullptr && rhs_scope == nullptr)
47    return lhs.GetPC() == rhs.GetPC();
48
49  return lhs_scope == rhs_scope;
50}
51
52bool lldb_private::operator!=(const StackID &lhs, const StackID &rhs) {
53  if (lhs.GetCallFrameAddress() != rhs.GetCallFrameAddress())
54    return true;
55
56  SymbolContextScope *lhs_scope = lhs.GetSymbolContextScope();
57  SymbolContextScope *rhs_scope = rhs.GetSymbolContextScope();
58
59  if (lhs_scope == nullptr && rhs_scope == nullptr)
60    return lhs.GetPC() != rhs.GetPC();
61
62  return lhs_scope != rhs_scope;
63}
64
65bool lldb_private::operator<(const StackID &lhs, const StackID &rhs) {
66  const lldb::addr_t lhs_cfa = lhs.GetCallFrameAddress();
67  const lldb::addr_t rhs_cfa = rhs.GetCallFrameAddress();
68
69  // FIXME: We are assuming that the stacks grow downward in memory.  That's not
70  // necessary, but true on
71  // all the machines we care about at present.  If this changes, we'll have to
72  // deal with that.  The ABI is the
73  // agent who knows this ordering, but the StackID has no access to the ABI.
74  // The most straightforward way
75  // to handle this is to add a "m_grows_downward" bool to the StackID, and set
76  // it in the constructor.
77  // But I'm not going to waste a bool per StackID on this till we need it.
78
79  if (lhs_cfa != rhs_cfa)
80    return lhs_cfa < rhs_cfa;
81
82  SymbolContextScope *lhs_scope = lhs.GetSymbolContextScope();
83  SymbolContextScope *rhs_scope = rhs.GetSymbolContextScope();
84
85  if (lhs_scope != nullptr && rhs_scope != nullptr) {
86    // Same exact scope, lhs is not less than (younger than rhs)
87    if (lhs_scope == rhs_scope)
88      return false;
89
90    SymbolContext lhs_sc;
91    SymbolContext rhs_sc;
92    lhs_scope->CalculateSymbolContext(&lhs_sc);
93    rhs_scope->CalculateSymbolContext(&rhs_sc);
94
95    // Items with the same function can only be compared
96    if (lhs_sc.function == rhs_sc.function && lhs_sc.function != nullptr &&
97        lhs_sc.block != nullptr && rhs_sc.function != nullptr &&
98        rhs_sc.block != nullptr) {
99      return rhs_sc.block->Contains(lhs_sc.block);
100    }
101  }
102  return false;
103}
104