pull request 88: thrift: clean up enum value assignment

GitHub user djwatson opened a pull request:

https://github.com/apache/thrift/pull/88

thrift: clean up enum value assignment

Summary:
Clean up how enum values are handled if an integer value is not
explicitly specified in the thrift file.

For example, the following used to be a compile error, but
works now:

enum MyEnum

{ SOMEVALUE }
struct MyStruct { 1: MyEnum e = SOMEVALUE }

This change also cleans up some of the error handling with out-of-range
values. Previously thrift simply issued a warning for enum values that
didn't fit in an i32, but serialized them as i32 anyway. Now
out-of-range enum values result in a compile failure.

Test Plan:
Included a new unit test to verify the assignment of enum values. I
also verified that g++ makes the same enum value assignments when
compiling these enums as C++ code.

You can merge this pull request into a Git repository by running:

$ git pull https://github.com/djwatson/thrift enum_parser

Alternatively you can review and apply these changes as the patch at:

https://github.com/apache/thrift/pull/88.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

This closes #88

----
commit 066cdfc0846dce8128263592efffa88084632a74
Author: Dave Watson <davejwatson@fb.com>
Date: 2014-03-25T18:51:47Z

thrift: clean up enum value assignment

Summary:
Clean up how enum values are handled if an integer value is not
explicitly specified in the thrift file.

For example, the following used to be a compile error, but
works now:

enum MyEnum { SOMEVALUE }

struct MyStruct

{ 1: MyEnum e = SOMEVALUE }

This change also cleans up some of the error handling with out-of-range
values. Previously thrift simply issued a warning for enum values that
didn't fit in an i32, but serialized them as i32 anyway. Now
out-of-range enum values result in a compile failure.

Test Plan:
Included a new unit test to verify the assignment of enum values. I
also verified that g++ makes the same enum value assignments when
compiling these enums as C++ code.