Reworking typeCheck to check unreachable sources

Author: grantnelson-wf

compiler/package.go

@@ -237,9 +237,15 @@ func PrepareAllSources(rootSrcs *sources.Sources, allSources []*sources.Sources,
 		srcs.Sort()
 	}
 
-	// This will be performed recursively for all dependencies to get the packages for the sources.
-	if err := rootSrcs.TypeCheck(importer, sizes32, tContext); err != nil {
-		return err
+	// This will be performed recursively for all dependencies
+	// to get the packages for the sources.
+	// Since some packages might not be recursively reached via the root source,
+	// e.g. runtime, we need to try to TypeCheck them all here.
+	// Any package already that has already run TypeCheck will be a no-op.
+	for _, srcs := range allSources {
+		if err := srcs.TypeCheck(importer, sizes32, tContext); err != nil {
+			return err
+		}
 	}
 
 	// Extract all go:linkname compiler directives from the package source.
@@ -254,6 +260,7 @@ func PrepareAllSources(rootSrcs *sources.Sources, allSources []*sources.Sources,
 		srcs.Simplify()
 	}
 
+	// Collect all the generic type instances from all the packages.
 	instances := &typeparams.PackageInstanceSets{}
 	for _, srcs := range allSources {
 		srcs.CollectInstances(tContext, instances)

compiler/sources/sources.go

@@ -94,8 +94,15 @@ func (s *Sources) Simplify() {
 // type information for the supplied AST.
 // This will set the Package field on the Sources.
 //
+// If the Package field is not nil, e.g. this function has already been run,
+// this will be a no-op.
+//
 // This must be called prior to simplify to get the types.Info used by simplify.
 func (s *Sources) TypeCheck(importer Importer, sizes types.Sizes, tContext *types.Context) error {
+	if s.Package != nil {
+		return nil
+	}
+
 	const errLimit = 10 // Max number of type checking errors to return.
 
 	typesInfo := &types.Info{