compiler: always sort interface parse methods

The exporter relies on sorting interface parse methods.  It would sort
them as it encountered interface types.  However, when an interface
type is an element of a struct or array type, the exporter might
encounter that interface type before sorting the parse methods.  If it
then encountered an identical interface type again, it could get
confused about whether the two types are identical or not.

Fix the problem by always sorting the parse methods in the
finalize_methods pass.

Also firm up the export type sorting to make sure we never have this
kind of confusion again.  Doing this revealed that we need to be more
careful about sorting in order to handle aliases correctly.

Also fix the interface type hash computation to use the right hash
value when looking at parse methods rather than all methods.

The test case for this is

Fixes golang/go#52841

Change-Id: I6243246148dbd96df8d2f2244516443d9bd6b114
Reviewed-by: Ian Lance Taylor <>
Reviewed-by: Than McIntosh <>
3 files changed
tree: 62af92392a31137c8f34a35d723ee1532f39cae4
  1. go/
  2. libgo/
  3. .gitignore
  5. codereview.cfg

A Go frontend

Ian Lance Taylor Last update 15 June 2014

This is a compiler frontend for the Go programming language. The frontend was originally developed at Google, and was released in November 2009. It was originally written by Ian Lance Taylor.

It was originally written for GCC. As of this writing it only supports GCC, but the GCC support has been separated from the rest of the frontend, so supporting another compiler is feasible.

The go subdirectory holds the frontend source code. This is mirrored to the gcc/go subdirectory in the GCC repository.

The libgo subdirectory holds the library source code. This is a copy of the main Go library with various changes appropriate for this compiler. The main Go library is hosted at, in the src directory. The libgo subdirectory is mirrored to the libgo subdirectory in the gcc repository.

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To contribute patches to the files in this directory, please see Contributing to the gccgo frontend.

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If the copyright holder for your code has already completed the agreement in connection with another Google open source project, it does not need to be completed again.

The authors of these files may be found in the AUTHORS and CONTRIBUTORS files.