summaryrefslogtreecommitdiff
path: root/Source/cmVariableWatchCommand.cxx
blob: 24394d96989921284f7316a3918520cc0d6acd16 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   file Copyright.txt or https://cmake.org/licensing for details.  */
#include "cmVariableWatchCommand.h"

#include <limits>
#include <memory>
#include <utility>

#include "cmExecutionStatus.h"
#include "cmListFileCache.h"
#include "cmMakefile.h"
#include "cmMessageType.h"
#include "cmStringAlgorithms.h"
#include "cmSystemTools.h"
#include "cmValue.h"
#include "cmVariableWatch.h"
#include "cmake.h"

class cmLocalGenerator;

namespace {
struct cmVariableWatchCallbackData
{
  bool InCallback;
  std::string Command;
};

void cmVariableWatchCommandVariableAccessed(const std::string& variable,
                                            int access_type, void* client_data,
                                            const char* newValue,
                                            const cmMakefile* mf)
{
  cmVariableWatchCallbackData* data =
    static_cast<cmVariableWatchCallbackData*>(client_data);

  if (data->InCallback) {
    return;
  }
  data->InCallback = true;

  auto accessString = cmVariableWatch::GetAccessAsString(access_type);

  /// Ultra bad!!
  cmMakefile* makefile = const_cast<cmMakefile*>(mf);

  std::string stack = *mf->GetProperty("LISTFILE_STACK");
  if (!data->Command.empty()) {
    cmValue const currentListFile =
      mf->GetDefinition("CMAKE_CURRENT_LIST_FILE");
    const auto fakeLineNo =
      std::numeric_limits<decltype(cmListFileArgument::Line)>::max();

    std::vector<cmListFileArgument> newLFFArgs{
      { variable, cmListFileArgument::Quoted, fakeLineNo },
      { accessString, cmListFileArgument::Quoted, fakeLineNo },
      { newValue ? newValue : "", cmListFileArgument::Quoted, fakeLineNo },
      { *currentListFile, cmListFileArgument::Quoted, fakeLineNo },
      { stack, cmListFileArgument::Quoted, fakeLineNo }
    };

    cmListFileFunction newLFF{ data->Command, fakeLineNo, fakeLineNo,
                               std::move(newLFFArgs) };
    cmExecutionStatus status(*makefile);
    if (!makefile->ExecuteCommand(newLFF, status)) {
      cmSystemTools::Error(
        cmStrCat("Error in cmake code at\nUnknown:0:\nA command failed "
                 "during the invocation of callback \"",
                 data->Command, "\"."));
    }
  } else {
    makefile->IssueMessage(
      MessageType::LOG,
      cmStrCat("Variable \"", variable, "\" was accessed using ", accessString,
               " with value \"", (newValue ? newValue : ""), "\"."));
  }

  data->InCallback = false;
}

void deleteVariableWatchCallbackData(void* client_data)
{
  cmVariableWatchCallbackData* data =
    static_cast<cmVariableWatchCallbackData*>(client_data);
  delete data;
}

/** This command does not really have a final pass but it needs to
    stay alive since it owns variable watch callback information. */
class FinalAction
{
public:
  /* NOLINTNEXTLINE(performance-unnecessary-value-param) */
  FinalAction(cmMakefile* makefile, std::string variable)
    : Action{ std::make_shared<Impl>(makefile, std::move(variable)) }
  {
  }

  void operator()(cmLocalGenerator&, const cmListFileBacktrace&) const {}

private:
  struct Impl
  {
    Impl(cmMakefile* makefile, std::string variable)
      : Makefile{ makefile }
      , Variable{ std::move(variable) }
    {
    }

    ~Impl()
    {
      this->Makefile->GetCMakeInstance()->GetVariableWatch()->RemoveWatch(
        this->Variable, cmVariableWatchCommandVariableAccessed);
    }

    cmMakefile* const Makefile;
    std::string const Variable;
  };

  std::shared_ptr<Impl const> Action;
};
} // anonymous namespace

bool cmVariableWatchCommand(std::vector<std::string> const& args,
                            cmExecutionStatus& status)
{
  if (args.empty()) {
    status.SetError("must be called with at least one argument.");
    return false;
  }
  std::string const& variable = args[0];
  std::string command;
  if (args.size() > 1) {
    command = args[1];
  }
  if (variable == "CMAKE_CURRENT_LIST_FILE") {
    status.SetError(cmStrCat("cannot be set on the variable: ", variable));
    return false;
  }

  auto* const data = new cmVariableWatchCallbackData;

  data->InCallback = false;
  data->Command = std::move(command);

  if (!status.GetMakefile().GetCMakeInstance()->GetVariableWatch()->AddWatch(
        variable, cmVariableWatchCommandVariableAccessed, data,
        deleteVariableWatchCallbackData)) {
    deleteVariableWatchCallbackData(data);
    return false;
  }

  status.GetMakefile().AddGeneratorAction(
    FinalAction{ &status.GetMakefile(), variable });
  return true;
}