cmd/go: refactor load.LoadPackage into other functions

LoadPackage was used to load a *load.Package for a command line
argument, after pattern expansion. It provided two special cases on
top of LoadImport. First, it ensured that "cmd/" packages in GOROOT
were installed in "$GOROOT/bin" or "$GOROOT/pkg/tool". Second, it
translated absolute paths to packages in GOROOT and GOPATH into
regular import paths.

With this change, LoadImport now ensures "cmd/" packages have the
right Target (without the need for a special case) and
search.ImportPaths translates absolute paths.

LoadPackage no longer handles these special cases and has been renamed
to LoadImportWithFlags, since it's still useful for loading implicit
dependencies.

Updates #29758

Change-Id: I9d54036f90c3ccd9b3a0fe0eaddaa7749593cc91
Reviewed-on: https://go-review.googlesource.com/c/go/+/167748
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

1 files changed, 2 insertions, 7 deletions

diff --git a/src/cmd/go/internal/get/get.go b/src/cmd/go/internal/get/get.go
index a314c57160..fe15515efc 100644
--- a/src/cmd/go/internal/get/get.go
+++ b/src/cmd/go/internal/get/get.go
@@ -177,12 +177,6 @@ func runGet(cmd *base.Command, args []string) {
 	// everything.
 	load.ClearPackageCache()
 
-	// In order to rebuild packages information completely,
-	// we need to clear commands cache. Command packages are
-	// referring to evicted packages from the package cache.
-	// This leads to duplicated loads of the standard packages.
-	load.ClearCmdCache()
-
 	pkgs := load.PackagesForBuild(args)
 
 	// Phase 3. Install.
@@ -240,7 +234,8 @@ func download(arg string, parent *load.Package, stk *load.ImportStack, mode int)
 	}
 	load1 := func(path string, mode int) *load.Package {
 		if parent == nil {
-			return load.LoadPackageNoFlags(path, stk)
+			mode := 0 // don't do module or vendor resolution
+			return load.LoadImport(path, base.Cwd, nil, stk, nil, mode)
 		}
 		return load.LoadImport(path, parent.Dir, parent, stk, nil, mode|load.ResolveModule)
 	}