introduce error_exceptiont

src/util/exception_utils.h

@@ -9,11 +9,12 @@ Author: Fotis Koutoulakis, fotis.koutoulakis@diffblue.com
 #ifndef CPROVER_UTIL_EXCEPTION_UTILS_H
 #define CPROVER_UTIL_EXCEPTION_UTILS_H
 
-#include <string>
-
 #include "invariant.h"
 #include "source_location.h"
 
+#include <sstream>
+#include <string>
+
 /// Base class for exceptions thrown in the cprover project.
 /// Intended to be used as a convenient way to have a
 /// "catch all and report errors" from application entry points.
@@ -190,4 +191,64 @@ class invalid_source_file_exceptiont : public invalid_input_exceptiont
   source_locationt source_location;
 };
 
+/// an exception class with optional source_locationt and exit code
+class error_exceptiont
+{
+public:
+  error_exceptiont() = default;
+  error_exceptiont(const error_exceptiont &other)
+  {
+    // ostringstream does not have a copy constructor
+    message << other.message.str();
+    __exit_code = other.__exit_code;
+    __location = other.__location;
+  }
+  error_exceptiont(error_exceptiont &&) = default;
+
+  std::string what() const
+  {
+    return message.str();
+  }
+
+  std::ostringstream &message_ostream()
+  {
+    return message;
+  }
+
+  std::optional<int> exit_code() const
+  {
+    return __exit_code;
+  }
+
+  error_exceptiont with_exit_code(int exit_code) &&
+  {
+    __exit_code = exit_code;
+    return std::move(*this);
+  }
+
+  error_exceptiont with_location(source_locationt _location) &&
+  {
+    __location = std::move(_location);
+    return std::move(*this);
+  }
+
+  const source_locationt &location() const
+  {
+    return __location;
+  }
+
+protected:
+  std::ostringstream message;
+  std::optional<int> __exit_code = {};
+  source_locationt __location = source_locationt::nil();
+};
+
+/// add to the diagnostic information in the given error_exceptiont exception
+template <typename T>
+error_exceptiont operator<<(error_exceptiont &&e, const T &message)
+{
+  e.message_ostream() << message;
+  return std::move(e);
+}
+
 #endif // CPROVER_UTIL_EXCEPTION_UTILS_H

unit/Makefile

@@ -150,6 +150,7 @@ SRC += analyses/ai/ai.cpp \
        util/dense_integer_map.cpp \
        util/dstring.cpp \
        util/edit_distance.cpp \
+       util/exception_utils.cpp \
        util/expr_cast/expr_cast.cpp \
        util/expr_initializer.cpp \
        util/expr.cpp \

unit/util/exception_utils.cpp

@@ -0,0 +1,89 @@
+/*******************************************************************\
+
+Module: Unit tests for error_exceptiont
+
+Author: Daniel Kroening
+
+\*******************************************************************/
+
+#include <util/exception_utils.h>
+
+#include <testing-utils/use_catch.h>
+
+TEST_CASE(
+  "error_exceptiont default construction",
+  "[core][util][exception_utils]")
+{
+  error_exceptiont e;
+  CHECK(e.what().empty());
+  CHECK_FALSE(e.exit_code().has_value());
+  CHECK(e.location().is_nil());
+}
+
+TEST_CASE(
+  "error_exceptiont with message via operator<<",
+  "[core][util][exception_utils]")
+{
+  auto e = error_exceptiont{} << "something went wrong";
+  CHECK(e.what() == "something went wrong");
+}
+
+TEST_CASE(
+  "error_exceptiont streaming multiple values",
+  "[core][util][exception_utils]")
+{
+  auto e = error_exceptiont{} << "error " << 42 << " occurred";
+  CHECK(e.what() == "error 42 occurred");
+}
+
+TEST_CASE("error_exceptiont with exit code", "[core][util][exception_utils]")
+{
+  auto e = error_exceptiont{}.with_exit_code(1);
+  REQUIRE(e.exit_code().has_value());
+  CHECK(e.exit_code().value() == 1);
+}
+
+TEST_CASE("error_exceptiont with location", "[core][util][exception_utils]")
+{
+  source_locationt loc;
+  loc.set_file("test.c");
+  loc.set_line("10");
+
+  auto e = error_exceptiont{}.with_location(loc);
+  CHECK(e.location().get_file() == "test.c");
+  CHECK(e.location().get_line() == "10");
+}
+
+TEST_CASE(
+  "error_exceptiont chaining all features",
+  "[core][util][exception_utils]")
+{
+  source_locationt loc;
+  loc.set_file("main.c");
+  loc.set_line("5");
+
+  auto e = error_exceptiont{}.with_exit_code(2).with_location(loc)
+           << "parse error";
+
+  CHECK(e.what() == "parse error");
+  REQUIRE(e.exit_code().has_value());
+  CHECK(e.exit_code().value() == 2);
+  CHECK(e.location().get_file() == "main.c");
+  CHECK(e.location().get_line() == "5");
+}
+
+TEST_CASE("error_exceptiont copy constructor", "[core][util][exception_utils]")
+{
+  auto original = error_exceptiont{}.with_exit_code(3);
+  original.message_ostream() << "copy test";
+
+  error_exceptiont copy(original);
+  CHECK(copy.what() == "copy test");
+  REQUIRE(copy.exit_code().has_value());
+  CHECK(copy.exit_code().value() == 3);
+
+  // Modifying the copy doesn't affect the original
+  copy.message_ostream() << " extra";
+  CHECK(copy.what() == "copy test extra");
+  CHECK(original.what() == "copy test");
+}