cmd/go/internal/modget: consolidate Load entrypoints

This change replaces ImportPaths, ImportPathsQuiet, LoadALL, and
LoadVendor with a single LoadPackages function, with a LoadOpts struct
that more clearly documents the variations in behavior.

It also eliminates the cmd/go/internal/load.ImportPaths function,
which was undocumented and had only one call site (within its own
package).

The modload.LoadTests global variable is subsumed by a field in the
new LoadOpts struct, and is no longer needed for callers that invoke
LoadPackages directly. It has been (temporarily) replaced with a
similar global variable, load.ModResolveTests, which can itself be
converted to an explicit, local argument.

For #37438
For #36460
Updates #40775
Fixes #26977

Change-Id: I4fb6086c01b04de829d98875db19cf0118d40f8c
Reviewed-on: https://go-review.googlesource.com/c/go/+/255938
Trust: Bryan C. Mills <bcmills@google.com>
Trust: Jay Conrod <jayconrod@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

1 files changed, 11 insertions, 4 deletions

diff --git a/src/cmd/go/internal/modget/get.go b/src/cmd/go/internal/modget/get.go
index f7b5cfaf2e..371ba8b690 100644
--- a/src/cmd/go/internal/modget/get.go
+++ b/src/cmd/go/internal/modget/get.go
@@ -284,7 +284,7 @@ func runGet(ctx context.Context, cmd *base.Command, args []string) {
 	if cfg.Insecure {
 		fmt.Fprintf(os.Stderr, "go get: -insecure flag is deprecated; see 'go help get' for details\n")
 	}
-	modload.LoadTests = *getT
+	load.ModResolveTests = *getT
 
 	// Do not allow any updating of go.mod until we've applied
 	// all the requested changes and checked that the result matches
@@ -314,7 +314,7 @@ func runGet(ctx context.Context, cmd *base.Command, args []string) {
 
 	// Add missing modules to the build list.
 	// We call SetBuildList here and elsewhere, since newUpgrader,
-	// ImportPathsQuiet, and other functions read the global build list.
+	// LoadPackages, and other functions read the global build list.
 	for _, q := range queries {
 		if _, ok := selectedVersion[q.m.Path]; !ok && q.m.Version != "none" {
 			buildList = append(buildList, q.m)
@@ -400,9 +400,16 @@ func runGet(ctx context.Context, cmd *base.Command, args []string) {
 
 		if len(pkgPatterns) > 0 {
 			// Don't load packages if pkgPatterns is empty. Both
-			// modload.ImportPathsQuiet and ModulePackages convert an empty list
+			// modload.LoadPackages and ModulePackages convert an empty list
 			// of patterns to []string{"."}, which is not what we want.
-			matches = modload.ImportPathsQuiet(ctx, pkgPatterns, imports.AnyTags())
+			loadOpts := modload.PackageOpts{
+				Tags:                     imports.AnyTags(),
+				ResolveMissingImports:    true, // dubious; see https://golang.org/issue/32567
+				LoadTests:                *getT,
+				AllowErrors:              true, // Errors may be fixed by subsequent upgrades or downgrades.
+				SilenceUnmatchedWarnings: true, // We will warn after iterating below.
+			}
+			matches, _ = modload.LoadPackages(ctx, loadOpts, pkgPatterns...)
 			seenPkgs = make(map[string]bool)
 			for i, match := range matches {
 				arg := pkgGets[i]