1 files changed, 64 insertions, 0 deletions
diff --git a/Source/cmVariableRequiresCommand.cxx b/Source/cmVariableRequiresCommand.cxx
new file mode 100644
index 0000000..06ca53c
--- /dev/null
+++ b/Source/cmVariableRequiresCommand.cxx
@@ -0,0 +1,64 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#include "cmVariableRequiresCommand.h"
+
+#include "cmMakefile.h"
+#include "cmState.h"
+#include "cmSystemTools.h"
+
+class cmExecutionStatus;
+
+// cmLibraryCommand
+bool cmVariableRequiresCommand::InitialPass(
+  std::vector<std::string> const& args, cmExecutionStatus&)
+{
+  if (args.size() < 3) {
+    this->SetError("called with incorrect number of arguments");
+    return false;
+  }
+
+  std::string const& testVariable = args[0];
+  if (!this->Makefile->IsOn(testVariable)) {
+    return true;
+  }
+  std::string const& resultVariable = args[1];
+  bool requirementsMet = true;
+  std::string notSet;
+  bool hasAdvanced = false;
+  cmState* state = this->Makefile->GetState();
+  for (unsigned int i = 2; i < args.size(); ++i) {
+    if (!this->Makefile->IsOn(args[i])) {
+      requirementsMet = false;
+      notSet += args[i];
+      notSet += "\n";
+      if (state->GetCacheEntryValue(args[i]) &&
+          state->GetCacheEntryPropertyAsBool(args[i], "ADVANCED")) {
+        hasAdvanced = true;
+      }
+    }
+  }
+  const char* reqVar = this->Makefile->GetDefinition(resultVariable);
+  // if reqVar is unset, then set it to requirementsMet
+  // if reqVar is set to true, but requirementsMet is false , then
+  // set reqVar to false.
+  if (!reqVar || (!requirementsMet && this->Makefile->IsOn(reqVar))) {
+    this->Makefile->AddDefinition(resultVariable, requirementsMet);
+  }
+
+  if (!requirementsMet) {
+    std::string message = "Variable assertion failed:\n";
+    message +=
+      testVariable + " Requires that the following unset variables are set:\n";
+    message += notSet;
+    message += "\nPlease set them, or set ";
+    message += testVariable + " to false, and re-configure.\n";
+    if (hasAdvanced) {
+      message +=
+        "One or more of the required variables is advanced."
+        "  To set the variable, you must turn on advanced mode in cmake.";
+    }
+    cmSystemTools::Error(message.c_str());
+  }
+
+  return true;
+}