1 files changed, 42 insertions, 12 deletions
diff --git a/Source/cmExprParserHelper.cxx b/Source/cmExprParserHelper.cxx
index fe7159a..8d3dad7 100644
--- a/Source/cmExprParserHelper.cxx
+++ b/Source/cmExprParserHelper.cxx
@@ -6,6 +6,8 @@
 
 #include <iostream>
 #include <sstream>
+#include <stdexcept>
+#include <utility>
 
 int cmExpr_yyparse(yyscan_t yyscanner);
 //
@@ -13,11 +15,11 @@ cmExprParserHelper::cmExprParserHelper()
 {
   this->FileLine = -1;
   this->FileName = nullptr;
+  this->Result = 0;
 }
 
 cmExprParserHelper::~cmExprParserHelper()
 {
-  this->CleanupParser();
 }
 
 int cmExprParserHelper::ParseString(const char* str, int verb)
@@ -37,16 +39,34 @@ int cmExprParserHelper::ParseString(const char* str, int verb)
   yyscan_t yyscanner;
   cmExpr_yylex_init(&yyscanner);
   cmExpr_yyset_extra(this, yyscanner);
-  int res = cmExpr_yyparse(yyscanner);
+
+  try {
+    int res = cmExpr_yyparse(yyscanner);
+    if (res != 0) {
+      std::string e = "cannot parse the expression: \"" + InputBuffer + "\": ";
+      e += ErrorString;
+      e += ".";
+      this->SetError(std::move(e));
+    }
+  } catch (std::runtime_error const& fail) {
+    std::string e =
+      "cannot evaluate the expression: \"" + InputBuffer + "\": ";
+    e += fail.what();
+    e += ".";
+    this->SetError(std::move(e));
+  } catch (std::out_of_range const&) {
+    std::string e = "cannot evaluate the expression: \"" + InputBuffer +
+      "\": a numeric value is out of range.";
+    this->SetError(std::move(e));
+  } catch (...) {
+    std::string e = "cannot parse the expression: \"" + InputBuffer + "\".";
+    this->SetError(std::move(e));
+  }
   cmExpr_yylex_destroy(yyscanner);
-  if (res != 0) {
-    // str << "CAL_Parser returned: " << res << std::endl;
-    // std::cerr << "When parsing: [" << str << "]" << std::endl;
+  if (!this->ErrorString.empty()) {
     return 0;
   }
 
-  this->CleanupParser();
-
   if (Verbose) {
     std::cerr << "Expanding [" << str << "] produced: [" << this->Result << "]"
               << std::endl;
@@ -54,10 +74,6 @@ int cmExprParserHelper::ParseString(const char* str, int verb)
   return 1;
 }
 
-void cmExprParserHelper::CleanupParser()
-{
-}
-
 int cmExprParserHelper::LexInput(char* buf, int maxlen)
 {
   // std::cout << "JPLexInput ";
@@ -85,7 +101,21 @@ void cmExprParserHelper::Error(const char* str)
   this->ErrorString = ostr.str();
 }
 
-void cmExprParserHelper::SetResult(int value)
+void cmExprParserHelper::UnexpectedChar(char c)
+{
+  unsigned long pos = static_cast<unsigned long>(this->InputBufferPos);
+  std::ostringstream ostr;
+  ostr << "Unexpected character in expression at position " << pos << ": " << c
+       << "\n";
+  this->WarningString += ostr.str();
+}
+
+void cmExprParserHelper::SetResult(KWIML_INT_int64_t value)
 {
   this->Result = value;
 }
+
+void cmExprParserHelper::SetError(std::string errorString)
+{
+  this->ErrorString = std::move(errorString);
+}