environment variable when building the toolchain using make.bash,
or you can set the CC environment variable any time you run the go tool.

The CXX_FOR_TARGET, CXX_FOR_${GOOS}_${GOARCH}, and CXX
environment variables work in a similar way for C++ code.

# Go references to C

Within the Go file, C's struct field names that are keywords in Go
can be accessed by prefixing them with an underscore: if x points at a C

There are, however, times when we cannot maintain complete compatibility.
If code depends on buggy (including insecure) behavior,
then fixing the bug will break that code.
New features can also have similar impacts:
enabling the HTTP/2 use by the HTTP client broke programs
connecting to servers with buggy HTTP/2 implementations.
These kinds of changes are unavoidable and
[permitted by the Go 1 compatibility rules](/doc/go1compat).

act as synchronization operations.
The effect of these operations on the synchronized-before partial order
is documented in the “Synchronization” section below.
Individual packages are responsible for providing similar documentation
for their own operations.
</p>

<h2 id="restrictions">Implementation Restrictions for Programs Containing Data Races</h2>

<p>