//go:build goexperiment.arenas

/*
The arena package provides the ability to allocate memory for a collection
of Go values and free that space manually all at once, safely. The purpose
of this functionality is to improve efficiency: manually freeing memory
before a garbage collection delays that cycle. Less frequent cycles means
the CPU cost of the garbage collector is incurred less frequently.

		w := NewWalker(context, "testdata/src/issue21181")
		pkg, err := w.import_("p")
		if err != nil {
			t.Fatalf("%s: (%s-%s) %s %v", err, context.GOOS, context.GOARCH,
				pkg.Name(), w.imported)
		}
		w.export(pkg)
	}
}

func TestIssue29837(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping with -short")
	}
	if *flagCheck {
		// slow, not worth repeating in -check

// Save references to C.xxx for later processing.
func (f *File) saveRef(n *ast.Expr, context astContext) {
	sel := (*n).(*ast.SelectorExpr)
	// For now, assume that the only instance of capital C is when
	// used as the imported package identifier.
	// The parser should take care of scoping in the future, so
	// that we will be able to distinguish a "top-level C" from a
	// local C.
	if l, ok := sel.X.(*ast.Ident); !ok || l.Name != "C" {

	-V
		Print cgo version and exit.
	-debug-define
		Debugging option. Print #defines.
	-debug-gcc
		Debugging option. Trace C compiler execution and output.
	-dynimport file
		Write list of symbols imported by file. Write to
		-dynout argument or to standard output. Used by go
		build when building a cgo package.
	-dynlinker
		Write dynamic linker as part of -dynimport output.
	-dynout file

	} else if escaped {
		err = errors.New("unfinished escaping")
	}
	return args, err
}

// Translate rewrites f.AST, the original Go input, to remove
// references to the imported package C, replacing them with
// references to the equivalent Go types, functions, and variables.
func (p *Package) Translate(f *File) {
	for _, cref := range f.Ref {
		// Convert C.ulong to C.unsigned long, etc.

	context     *build.Context
	root        string
	scope       []string
	current     *apiPackage
	deprecated  map[token.Pos]bool
	features    map[string]bool              // set
	imported    map[string]*apiPackage       // packages already imported
	stdPackages []string                     // names, omitting "unsafe", internal, and vendored packages
	importMap   map[string]map[string]string // importer dir -> import path -> canonical path

	// #include <gmp.h>
	import "C"

is a signal to cgo.  The doc comment on the import of "C" provides
additional context for the C file.  Here it is just a single #include
but it could contain arbitrary C definitions to be imported and used.

Cgo recognizes any use of a qualified identifier C.xxx and uses gcc to
find the definition of xxx.  If xxx is a type, cgo replaces C.xxx with
a Go translation.  C arithmetic types translate to precisely-sized Go