SERVER-12770 Change stringification and casting of ErrorCodes::Error to improve round-tripping.

4 files changed, 21 insertions, 23 deletions

diff --git a/src/mongo/base/generate_error_codes.py b/src/mongo/base/generate_error_codes.py
index 19330d1ff57..eee41afce2a 100644
--- a/src/mongo/base/generate_error_codes.py
+++ b/src/mongo/base/generate_error_codes.py
@@ -158,6 +158,8 @@ header_template = '''// AUTO-GENERATED FILE DO NOT EDIT
 
 #pragma once
 
+#include <string>
+
 #include "mongo/base/string_data.h"
 #include "mongo/client/export_macros.h"
 
@@ -177,19 +179,19 @@ namespace mongo {
             MaxError
         };
 
-        static const char* errorString(Error err);
+        static std::string errorString(Error err);
 
         /**
-         * Parse an Error from its "name".  Returns UnknownError if "name" is unrecognized.
+         * Parses an Error from its "name".  Returns UnknownError if "name" is unrecognized.
          *
          * NOTE: Also returns UnknownError for the string "UnknownError".
          */
         static Error fromString(const StringData& name);
 
         /**
-         * Parse an Error from its "code".  Returns UnknownError if "code" is unrecognized.
-         *
-         * NOTE: Also returns UnknownError for the integer code for UnknownError.
+         * Casts an integer "code" to an Error.  Unrecognized codes are preserved, meaning
+         * that the result of a call to fromInt() may not be one of the values in the
+         * Error enumeration.
          */
         static Error fromInt(int code);
 
@@ -218,13 +220,16 @@ source_template = '''// AUTO-GENERATED FILE DO NOT EDIT
 
 #include "mongo/base/error_codes.h"
 
-#include <cstring>
+#include <boost/static_assert.hpp>
+
+#include "mongo/util/mongoutils/str.h"
 
 namespace mongo {
-    const char* ErrorCodes::errorString(Error err) {
+
+    std::string ErrorCodes::errorString(Error err) {
         switch (err) {
         %(symbol_to_string_cases)s;
-        default: return "Unknown error code";
+        default: return mongoutils::str::stream() << "Location" << err;
         }
     }
 
@@ -234,14 +239,14 @@ namespace mongo {
     }
 
     ErrorCodes::Error ErrorCodes::fromInt(int code) {
-        switch (code) {
-        %(int_to_symbol_cases)s;
-        default:
-            return UnknownError;
-        }
+        return static_cast<Error>(code);
     }
 
     %(error_code_class_predicate_definitions)s
+
+namespace {
+    BOOST_STATIC_ASSERT(sizeof(ErrorCodes::Error) == sizeof(int));
+}  // namespace
 }  // namespace mongo
 '''
 
diff --git a/src/mongo/base/status-inl.h b/src/mongo/base/status-inl.h
index 22679707b6c..add962e2369 100644
--- a/src/mongo/base/status-inl.h
+++ b/src/mongo/base/status-inl.h
@@ -45,7 +45,7 @@ namespace mongo {
         return _error ? _error->code : ErrorCodes::OK;
     }
 
-    inline const char* Status::codeString() const {
+    inline std::string Status::codeString() const {
         return ErrorCodes::errorString(code());
     }
 
diff --git a/src/mongo/base/status.h b/src/mongo/base/status.h
index 275cb767e55..ad301f8b008 100644
--- a/src/mongo/base/status.h
+++ b/src/mongo/base/status.h
@@ -89,7 +89,7 @@ namespace mongo {
 
         inline ErrorCodes::Error code() const;
 
-        inline const char* codeString() const;
+        inline std::string codeString() const;
 
         inline std::string reason() const;
 
diff --git a/src/mongo/base/status_test.cpp b/src/mongo/base/status_test.cpp
index f0cb473f22c..abda898c7f5 100644
--- a/src/mongo/base/status_test.cpp
+++ b/src/mongo/base/status_test.cpp
@@ -78,15 +78,8 @@ namespace {
     TEST(Parsing, CodeToEnum) {
         ASSERT_EQUALS(ErrorCodes::TypeMismatch, ErrorCodes::fromInt(ErrorCodes::TypeMismatch));
         ASSERT_EQUALS(ErrorCodes::UnknownError, ErrorCodes::fromInt(ErrorCodes::UnknownError));
-        ASSERT_EQUALS(ErrorCodes::UnknownError, ErrorCodes::fromInt(ErrorCodes::MaxError));
+        ASSERT_EQUALS(ErrorCodes::MaxError, ErrorCodes::fromInt(ErrorCodes::MaxError));
         ASSERT_EQUALS(ErrorCodes::OK, ErrorCodes::fromInt(0));
     }
 
-    TEST(Parsing, StringToEnum) {
-        ASSERT_EQUALS(ErrorCodes::TypeMismatch, ErrorCodes::fromString("TypeMismatch"));
-        ASSERT_EQUALS(ErrorCodes::UnknownError, ErrorCodes::fromString("UnknownError"));
-        ASSERT_EQUALS(ErrorCodes::UnknownError, ErrorCodes::fromString("Garbage"));
-        ASSERT_EQUALS(ErrorCodes::OK, ErrorCodes::fromString("OK"));
-    }
-
 } // unnamed namespace