These are some notes on contributing to the gccgo
frontend for GCC. For information on contributing to parts of Go other
than gccgo, see Contributing to
the Go project. For information on building gccgo
for yourself, see Setting up and using
gccgo.
The gccgo frontend is part of the GCC compiler, and it
follows the GCC
contribution rules. In particular, for substantial
patches—more than 10 lines—you must have a copyright
assignment with the Free Software Foundation.
The source code for the gccgo frontend may be found in
the directory gcc/go. The frontend is written in C++ and
as such the GNU coding standards do not entirely apply; in writing
code for the frontend, follow the formatting of the surrounding code.
Although the frontend is currently closely tied to the rest of the gcc
codebase, we plan to make it more independent. Any new code which
uses other parts of gcc should be segregated in an appropriate file,
such as gogo-tree.cc.
The runtime library for gccgo is mostly the same as the
library in the main Mercurial repository. The library code in the
Mercurial repository is periodically copied into
the gccgo repository. Accordingly, most library changes
should be made in Mercurial. Changes to the few gccgo
specific parts of the library should follow the process described
here. The gccgo specific parts of the library are
everything in the libgo directory except for
the libgo/go subdirectory.
All patches must be tested. There are two test suites. A patch that introduces new failures is not acceptable.
To run the compiler test suite, run make check-go in the
gcc subdirectory of your build directory. This will run
various tests underneath gcc/testsuite/go.*. This
includes a copy of the tests in the Mercurial repository, which are
run using the DejaGNU script found in
in gcc/testsuite/go.test/go-test.exp. Many of the
compiler tests may be run without the Go library, but some do require
the library to built first.
To run the library test suite, run make
check-target-libgo in the top level of your build directory.
Most new tests should be submitted to the Mercurial repository for
copying into the gccgo repository. If there is a need
for specific tests for gccgo, they should go in
the gcc/testsuite/go.go-torture
or gcc/testsuite/go.dg directories.
Proposing a patch should follow the standard GCC rules. That is, the
patch should be sent to the mailing
list gcc-patches@gcc.gnu.org as a diff—the output
of the diff program with the -c
or -u option. In the future we are likely to set up a
separate gccgo-specific mailing list, which should also be CC'ed; we
will update this document at that time. Patch emails should include a
ChangeLog entry, though the ChangeLog entry should not be in the diff
itself. ChangeLog files are a standard part of GNU programs; see
the
GNU coding standards.