compiler: Restore previous behavior of skipping unsafe import.

dmitshur · dmitshur · commit 853e795aa016 · 2017-08-25T14:23:37.000-04:00
If its code were to be generated, package unsafe ends up largely empty: $packages["unsafe"] = (function() { var $pkg = {}, $init; $init = function() { $pkg.$init = function() {}; ... }; $pkg.$init = $init; return $pkg; })(); It contains an empty (aside from goroutine/blocking bookkeeping code) init function, and that's the only thing that gets called by other packages. So, we don't want to start including it. This change restores the previous behavior (with Go 1.8) of skipping it. Helps gopherjs/gopherjs.github.io#67 (comment). Related to https://golang.org/cl/37694.
diff --git a/compiler/package.go b/compiler/package.go
@@ -217,6 +217,11 @@ func Compile(importPath string, files []*ast.File, fileSet *token.FileSet, impor
 	var importDecls []*Decl
 	var importedPaths []string
 	for _, importedPkg := range typesPkg.Imports() {
+		if importedPkg == types.Unsafe {
+			// Prior to Go 1.9, unsafe import was excluded by Imports() method,
+			// but now we do it here to maintain previous behavior.
+			continue
+		}
 		c.p.pkgVars[importedPkg.Path()] = c.newVariableWithLevel(importedPkg.Name(), true)
 		importedPaths = append(importedPaths, importedPkg.Path())
 	}
