1 files changed, 56 insertions, 2 deletions

diff --git a/Source/cmMathCommand.cxx b/Source/cmMathCommand.cxx
index ab77dc3..5d1b099 100644
--- a/Source/cmMathCommand.cxx
+++ b/Source/cmMathCommand.cxx
@@ -28,16 +28,59 @@ bool cmMathCommand::InitialPass(std::vector<std::string> const& args,
 
 bool cmMathCommand::HandleExprCommand(std::vector<std::string> const& args)
 {
-  if (args.size() != 3) {
+  if ((args.size() != 3) && (args.size() != 5)) {
     this->SetError("EXPR called with incorrect arguments.");
     return false;
   }
 
+  enum class NumericFormat
+  {
+    UNINITIALIZED,
+    DECIMAL,
+    HEXADECIMAL,
+  };
+
   const std::string& outputVariable = args[1];
   const std::string& expression = args[2];
+  size_t argumentIndex = 3;
+  NumericFormat outputFormat = NumericFormat::UNINITIALIZED;
 
   this->Makefile->AddDefinition(outputVariable, "ERROR");
 
+  if (argumentIndex < args.size()) {
+    const std::string messageHint = "sub-command EXPR ";
+    const std::string option = args[argumentIndex++];
+    if (option == "OUTPUT_FORMAT") {
+      if (argumentIndex < args.size()) {
+        const std::string argument = args[argumentIndex++];
+        if (argument == "DECIMAL") {
+          outputFormat = NumericFormat::DECIMAL;
+        } else if (argument == "HEXADECIMAL") {
+          outputFormat = NumericFormat::HEXADECIMAL;
+        } else {
+          std::string error = messageHint + "value \"" + argument +
+            "\" for option \"" + option + "\" is invalid.";
+          this->SetError(error);
+          return false;
+        }
+      } else {
+        std::string error =
+          messageHint + "missing argument for option \"" + option + "\".";
+        this->SetError(error);
+        return false;
+      }
+    } else {
+      std::string error =
+        messageHint + "option \"" + option + "\" is unknown.";
+      this->SetError(error);
+      return false;
+    }
+  }
+
+  if (outputFormat == NumericFormat::UNINITIALIZED) {
+    outputFormat = NumericFormat::DECIMAL;
+  }
+
   cmExprParserHelper helper;
   if (!helper.ParseString(expression.c_str(), 0)) {
     this->SetError(helper.GetError());
@@ -45,7 +88,18 @@ bool cmMathCommand::HandleExprCommand(std::vector<std::string> const& args)
   }
 
   char buffer[1024];
-  sprintf(buffer, "%" KWIML_INT_PRId64, helper.GetResult());
+  const char* fmt;
+  switch (outputFormat) {
+    case NumericFormat::HEXADECIMAL:
+      fmt = "0x%" KWIML_INT_PRIx64;
+      break;
+    case NumericFormat::DECIMAL:
+      CM_FALLTHROUGH;
+    default:
+      fmt = "%" KWIML_INT_PRId64;
+      break;
+  }
+  sprintf(buffer, fmt, helper.GetResult());
 
   this->Makefile->AddDefinition(outputVariable, buffer);
   return true;