1//===-- StackID.cpp -------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "lldb/Target/StackID.h"
10#include "lldb/Symbol/Block.h"
11#include "lldb/Symbol/Symbol.h"
12#include "lldb/Symbol/SymbolContext.h"
13#include "lldb/Utility/Stream.h"
14
15using namespace lldb_private;
16
17void StackID::Dump(Stream *s) {
18  s->Printf("StackID (pc = 0x%16.16" PRIx64 ", cfa = 0x%16.16" PRIx64
19            ", symbol_scope = %p",
20            m_pc, m_cfa, static_cast<void *>(m_symbol_scope));
21  if (m_symbol_scope) {
22    SymbolContext sc;
23
24    m_symbol_scope->CalculateSymbolContext(&sc);
25    if (sc.block)
26      s->Printf(" (Block {0x%8.8" PRIx64 "})", sc.block->GetID());
27    else if (sc.symbol)
28      s->Printf(" (Symbol{0x%8.8x})", sc.symbol->GetID());
29  }
30  s->PutCString(") ");
31}
32
33bool lldb_private::operator==(const StackID &lhs, const StackID &rhs) {
34  if (lhs.GetCallFrameAddress() != rhs.GetCallFrameAddress())
35    return false;
36
37  SymbolContextScope *lhs_scope = lhs.GetSymbolContextScope();
38  SymbolContextScope *rhs_scope = rhs.GetSymbolContextScope();
39
40  // Only compare the PC values if both symbol context scopes are nullptr
41  if (lhs_scope == nullptr && rhs_scope == nullptr)
42    return lhs.GetPC() == rhs.GetPC();
43
44  return lhs_scope == rhs_scope;
45}
46
47bool lldb_private::operator!=(const StackID &lhs, const StackID &rhs) {
48  if (lhs.GetCallFrameAddress() != rhs.GetCallFrameAddress())
49    return true;
50
51  SymbolContextScope *lhs_scope = lhs.GetSymbolContextScope();
52  SymbolContextScope *rhs_scope = rhs.GetSymbolContextScope();
53
54  if (lhs_scope == nullptr && rhs_scope == nullptr)
55    return lhs.GetPC() != rhs.GetPC();
56
57  return lhs_scope != rhs_scope;
58}
59
60bool lldb_private::operator<(const StackID &lhs, const StackID &rhs) {
61  const lldb::addr_t lhs_cfa = lhs.GetCallFrameAddress();
62  const lldb::addr_t rhs_cfa = rhs.GetCallFrameAddress();
63
64  // FIXME: We are assuming that the stacks grow downward in memory.  That's not
65  // necessary, but true on
66  // all the machines we care about at present.  If this changes, we'll have to
67  // deal with that.  The ABI is the agent who knows this ordering, but the
68  // StackID has no access to the ABI. The most straightforward way to handle
69  // this is to add a "m_grows_downward" bool to the StackID, and set it in the
70  // constructor. But I'm not going to waste a bool per StackID on this till we
71  // need it.
72
73  if (lhs_cfa != rhs_cfa)
74    return lhs_cfa < rhs_cfa;
75
76  SymbolContextScope *lhs_scope = lhs.GetSymbolContextScope();
77  SymbolContextScope *rhs_scope = rhs.GetSymbolContextScope();
78
79  if (lhs_scope != nullptr && rhs_scope != nullptr) {
80    // Same exact scope, lhs is not less than (younger than rhs)
81    if (lhs_scope == rhs_scope)
82      return false;
83
84    SymbolContext lhs_sc;
85    SymbolContext rhs_sc;
86    lhs_scope->CalculateSymbolContext(&lhs_sc);
87    rhs_scope->CalculateSymbolContext(&rhs_sc);
88
89    // Items with the same function can only be compared
90    if (lhs_sc.function == rhs_sc.function && lhs_sc.function != nullptr &&
91        lhs_sc.block != nullptr && rhs_sc.function != nullptr &&
92        rhs_sc.block != nullptr) {
93      return rhs_sc.block->Contains(lhs_sc.block);
94    }
95  }
96  return false;
97}
98