handling, at some cost in run time, is available by setting
GOEXPERIMENT=cgocheck2 at build time.

It is possible to defeat this enforcement by using the unsafe package,
and of course there is nothing stopping the C code from doing anything
it likes. However, programs that break these rules are likely to fail
in unexpected and unpredictable ways.

The runtime/cgo.Handle type can be used to safely pass Go values

For the remaining programs,
we define a new GODEBUG setting that
allows individual programs to opt back in to the old behavior.
A GODEBUG setting may not be added if doing so is infeasible,
but that should be extremely rare.

GODEBUG settings added for compatibility will be maintained
for a minimum of two years (four Go releases).
Some, such as `http2client` and `http2server`,

	// The start index is inclusive and the end index is exclusive.
	type span struct {
		start int
		end   int
	}
	spans := make([]span, 0, 32)

	// Find the field start and end indices.
	// Doing this in a separate pass (rather than slicing the string s
	// and collecting the result substrings right away) is significantly
	// more efficient, possibly due to cache effects.
	start := -1 // valid span start if >= 0

It implements these forms as multiple instructions, often using the <code>R11</code> register
to hold temporary values.
Hand-written assembly can use <code>R11</code>, but doing so requires
being sure that the linker is not also using it to implement any of the other
instructions in the function.
</p>

<p>
When defining a <code>TEXT</code>, specifying frame size <code>$-4</code>

// into Go.
func testCallbackCallersSEH(t *testing.T) {
	testenv.SkipIfOptimizationOff(t) // This test requires inlining.
	if runtime.Compiler != "gc" {
		// The exact function names are not going to be the same.
		t.Skip("skipping for non-gc toolchain")
	}
	if runtime.GOARCH != "amd64" {
		// TODO: support SEH on other architectures.
		t.Skip("skipping on non-amd64")
	}

<!--
We should be able to simplify the rules for comparable or delegate some of them
elsewhere since we have a section that clearly defines how interfaces implement
other interfaces based on their type sets. But this should get us going for now.
-->

<p>
The <a href="#Predeclared_identifiers">predeclared</a>
<a href="#Interface_types">interface type</a> <code>comparable</code>
denotes the set of all non-interface types that are

			if err != nil {
				log.Fatalf("go list: invalid output: %v", err)
			}

			// - Package "unsafe" contains special signatures requiring
			//   extra care when printing them - ignore since it is not
			//   going to change w/o a language change.
			// - Internal and vendored packages do not contribute to our
			//   API surface. (If we are running within the "std" module,
			//   vendored dependencies appear as themselves instead of