1 files changed, 130 insertions, 0 deletions
diff --git a/Source/cmVariableWatchCommand.cxx b/Source/cmVariableWatchCommand.cxx
new file mode 100644
index 0000000..5fe55bd
--- /dev/null
+++ b/Source/cmVariableWatchCommand.cxx
@@ -0,0 +1,130 @@
+/* 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 <sstream>
+
+#include "cmExecutionStatus.h"
+#include "cmListFileCache.h"
+#include "cmMakefile.h"
+#include "cmMessageType.h"
+#include "cmSystemTools.h"
+#include "cmVariableWatch.h"
+#include "cmake.h"
+
+struct cmVariableWatchCallbackData
+{
+  bool InCallback;
+  std::string Command;
+};
+
+static 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;
+
+  cmListFileFunction newLFF;
+  cmListFileArgument arg;
+  bool processed = false;
+  const char* accessString = cmVariableWatch::GetAccessAsString(access_type);
+  const char* currentListFile = mf->GetDefinition("CMAKE_CURRENT_LIST_FILE");
+
+  /// Ultra bad!!
+  cmMakefile* makefile = const_cast<cmMakefile*>(mf);
+
+  std::string stack = makefile->GetProperty("LISTFILE_STACK");
+  if (!data->Command.empty()) {
+    newLFF.Arguments.clear();
+    newLFF.Arguments.emplace_back(variable, cmListFileArgument::Quoted, 9999);
+    newLFF.Arguments.emplace_back(accessString, cmListFileArgument::Quoted,
+                                  9999);
+    newLFF.Arguments.emplace_back(newValue ? newValue : "",
+                                  cmListFileArgument::Quoted, 9999);
+    newLFF.Arguments.emplace_back(currentListFile, cmListFileArgument::Quoted,
+                                  9999);
+    newLFF.Arguments.emplace_back(stack, cmListFileArgument::Quoted, 9999);
+    newLFF.Name = data->Command;
+    newLFF.Line = 9999;
+    cmExecutionStatus status;
+    if (!makefile->ExecuteCommand(newLFF, status)) {
+      std::ostringstream error;
+      error << "Error in cmake code at\nUnknown:0:\n"
+            << "A command failed during the invocation of callback \""
+            << data->Command << "\".";
+      cmSystemTools::Error(error.str());
+      data->InCallback = false;
+      return;
+    }
+    processed = true;
+  }
+  if (!processed) {
+    std::ostringstream msg;
+    msg << "Variable \"" << variable << "\" was accessed using "
+        << accessString << " with value \"" << (newValue ? newValue : "")
+        << "\".";
+    makefile->IssueMessage(MessageType::LOG, msg.str());
+  }
+
+  data->InCallback = false;
+}
+
+static void deleteVariableWatchCallbackData(void* client_data)
+{
+  cmVariableWatchCallbackData* data =
+    static_cast<cmVariableWatchCallbackData*>(client_data);
+  delete data;
+}
+
+cmVariableWatchCommand::cmVariableWatchCommand() = default;
+
+cmVariableWatchCommand::~cmVariableWatchCommand()
+{
+  for (std::string const& wv : this->WatchedVariables) {
+    this->Makefile->GetCMakeInstance()->GetVariableWatch()->RemoveWatch(
+      wv, cmVariableWatchCommandVariableAccessed);
+  }
+}
+
+bool cmVariableWatchCommand::InitialPass(std::vector<std::string> const& args,
+                                         cmExecutionStatus&)
+{
+  if (args.empty()) {
+    this->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") {
+    std::ostringstream ostr;
+    ostr << "cannot be set on the variable: " << variable;
+    this->SetError(ostr.str());
+    return false;
+  }
+
+  cmVariableWatchCallbackData* data = new cmVariableWatchCallbackData;
+
+  data->InCallback = false;
+  data->Command = command;
+
+  this->WatchedVariables.insert(variable);
+  if (!this->Makefile->GetCMakeInstance()->GetVariableWatch()->AddWatch(
+        variable, cmVariableWatchCommandVariableAccessed, data,
+        deleteVariableWatchCallbackData)) {
+    deleteVariableWatchCallbackData(data);
+    return false;
+  }
+
+  return true;
+}