Add invalid_source_file_exceptiont

This exception was added to indicate that one or more of the input files we have
has a problem that prevents us from working with it, such as being syntactically
invalid.

Author: hannes-steffenhagen-diffblue

src/util/exception_utils.cpp

@@ -86,3 +86,8 @@ std::string analysis_exceptiont::what() const
 {
   return reason;
 }
+
+std::string invalid_source_file_exceptiont::what() const
+{
+  return reason;
+}

src/util/exception_utils.h

@@ -120,4 +120,16 @@ class analysis_exceptiont : public cprover_exception_baset
   std::string reason;
 };
 
+/// Thrown when we can't handle something in an input source file.
+/// For example, if we get C source code that is not syntactically valid
+/// or that has type errors.
+class invalid_source_file_exceptiont : public cprover_exception_baset
+{
+public:
+  std::string what() const override;
+
+private:
+  std::string reason;
+};
+
 #endif // CPROVER_UTIL_EXCEPTION_UTILS_H