internal/lsp/cache: remove type info trimming

This broke staticcheck and x/tools/refactor, most notably used for our
rename support. Doesn't look like a winner. Roll it back :(

Updates golang/go#45457.

Change-Id: I30d5aa160fd9319329d36b2a534ee3c756090726
Reviewed-on: https://go-review.googlesource.com/c/tools/+/311549
Trust: Heschi Kreinick <[email protected]>
Run-TryBot: Heschi Kreinick <[email protected]>
Reviewed-by: Robert Findley <[email protected]>
gopls-CI: kokoro <[email protected]>

Author: heschi

internal/lsp/cache/check.go

@@ -446,6 +446,7 @@ func typeCheck(ctx context.Context, snapshot *snapshot, m *metadata, mode source
 	typesinternal.SetUsesCgo(cfg)
 
 	check := types.NewChecker(cfg, fset, pkg.types, pkg.typesInfo)
+
 	// Type checking errors are handled via the config, so ignore them here.
 	_ = check.Files(files)
 	// If the context was cancelled, we may have returned a ton of transient
@@ -454,12 +455,6 @@ func typeCheck(ctx context.Context, snapshot *snapshot, m *metadata, mode source
 		return nil, ctx.Err()
 	}
 
-	// staticcheck requires full type information. Reduce memory usage for
-	// everyone else.
-	if !snapshot.view.Options().Staticcheck {
-		trimTypesInfo(files, pkg.typesInfo)
-	}
-
 	// We don't care about a package's errors unless we have parsed it in full.
 	if mode != source.ParseFull {
 		return pkg, nil
@@ -800,33 +795,3 @@ func isValidImport(pkgPath, importPkgPath packagePath) bool {
 type importerFunc func(path string) (*types.Package, error)
 
 func (f importerFunc) Import(path string) (*types.Package, error) { return f(path) }
-
-func trimTypesInfo(files []*ast.File, info *types.Info) {
-	for _, file := range files {
-		ast.Inspect(file, func(n ast.Node) bool {
-			if n == nil {
-				return false
-			}
-			cl, ok := n.(*ast.CompositeLit)
-			if !ok {
-				return true
-			}
-
-			// types.Info.Types for long slice/array literals are particularly
-			// expensive. Try to clear them out.
-			if _, ok := cl.Type.(*ast.ArrayType); !ok {
-				return true
-			}
-
-			for _, elt := range cl.Elts {
-				// Only delete information for basic literals; other elements,
-				// like constants and function calls, could still be relevant.
-				if _, ok := elt.(*ast.BasicLit); ok {
-					delete(info.Types, elt)
-				}
-			}
-
-			return true
-		})
-	}
-}