cmd/go/internal/modload: remove the Reqs function

The Reqs function returns an mvs.Reqs implemention for the global
build list. The API that it presents assumes that the build list is
globally consistent (problematic for #40775) and readily available
(problematic for #36460).

Fortunately, it is no longer used outside of the modload package.
We can instead use individual instances of the unexported mvsReqs
struct, making the dependency on the global build list more explicit.

For #36460
For #40775

Change-Id: I8674442f2a86416b0bf9c3395cb591c1e724c9d2
Reviewed-on: https://go-review.googlesource.com/c/go/+/272129
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

diff --git a/src/cmd/go/internal/modload/init.go b/src/cmd/go/internal/modload/init.go
index b9345acbce2dc740a2244579503f18522360006b..a9b77c82b353b97e50271cec0cbe20756950282b 100644 (file)
--- a/src/cmd/go/internal/modload/init.go
+++ b/src/cmd/go/internal/modload/init.go
@@ -853,7 +853,7 @@ func MinReqs() mvs.Reqs {
                        retain = append(retain, m.Path)
                }
        }
-       min, err := mvs.Req(Target, retain, Reqs())
+       min, err := mvs.Req(Target, retain, &mvsReqs{buildList: buildList})
        if err != nil {
                base.Fatalf("go: %v", err)
        }
@@ -985,7 +985,7 @@ func keepSums(addDirect bool) map[module.Version]bool {
        keep := make(map[module.Version]bool)
        var mu sync.Mutex
        reqs := &keepSumReqs{
-               Reqs: Reqs(),
+               Reqs: &mvsReqs{buildList: buildList},
                visit: func(m module.Version) {
                        // If we build using a replacement module, keep the sum for the replacement,
                        // since that's the code we'll actually use during a build.

diff --git a/src/cmd/go/internal/modload/load.go b/src/cmd/go/internal/modload/load.go
index 302330278eba273784aabdcedc5fdc983bc22642..732c4af92b57375129627d5c6c25c4ee75dacc5d 100644 (file)
--- a/src/cmd/go/internal/modload/load.go
+++ b/src/cmd/go/internal/modload/load.go
@@ -800,7 +800,7 @@ func loadFromRoots(params loaderParams) *loader {
        }
 
        var err error
-       reqs := Reqs()
+       reqs := &mvsReqs{buildList: buildList}
        buildList, err = mvs.BuildList(Target, reqs)
        if err != nil {
                base.Fatalf("go: %v", err)
@@ -842,7 +842,7 @@ func loadFromRoots(params loaderParams) *loader {
                }
 
                // Recompute buildList with all our additions.
-               reqs = Reqs()
+               reqs = &mvsReqs{buildList: buildList}
                buildList, err = mvs.BuildList(Target, reqs)
                if err != nil {
                        // If an error was found in a newly added module, report the package

diff --git a/src/cmd/go/internal/modload/mvs.go b/src/cmd/go/internal/modload/mvs.go
index db57b3ec5fe4c18abc26324d2406e83d1299edf2..167d6819b06ae51620dc01195eacc30d17116ae1 100644 (file)
--- a/src/cmd/go/internal/modload/mvs.go
+++ b/src/cmd/go/internal/modload/mvs.go
@@ -11,7 +11,6 @@ import (
        "sort"
 
        "cmd/go/internal/modfetch"
-       "cmd/go/internal/mvs"
 
        "golang.org/x/mod/module"
        "golang.org/x/mod/semver"
@@ -23,16 +22,6 @@ type mvsReqs struct {
        buildList []module.Version
 }
 
-// Reqs returns the current module requirement graph.
-// Future calls to EditBuildList do not affect the operation
-// of the returned Reqs.
-func Reqs() mvs.Reqs {
-       r := &mvsReqs{
-               buildList: buildList,
-       }
-       return r
-}
-
 func (r *mvsReqs) Required(mod module.Version) ([]module.Version, error) {
        if mod == Target {
                // Use the build list as it existed when r was constructed, not the current

diff --git a/src/cmd/go/internal/modload/mvs_test.go b/src/cmd/go/internal/modload/mvs_test.go
index 0cb376ec3c06fc124dabf56e91f1d38802fdde03..50e93c381fdd1d4fba4c99c939368c0e04f5a9d3 100644 (file)
--- a/src/cmd/go/internal/modload/mvs_test.go
+++ b/src/cmd/go/internal/modload/mvs_test.go
@@ -2,19 +2,17 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package modload_test
+package modload
 
 import (
        "testing"
-
-       "cmd/go/internal/modload"
 )
 
 func TestReqsMax(t *testing.T) {
        type testCase struct {
                a, b, want string
        }
-       reqs := modload.Reqs()
+       reqs := new(mvsReqs)
        for _, tc := range []testCase{
                {a: "v0.1.0", b: "v0.2.0", want: "v0.2.0"},
                {a: "v0.2.0", b: "v0.1.0", want: "v0.2.0"},
@@ -27,7 +25,7 @@ func TestReqsMax(t *testing.T) {
        } {
                max := reqs.Max(tc.a, tc.b)
                if max != tc.want {
-                       t.Errorf("Reqs().Max(%q, %q) = %q; want %q", tc.a, tc.b, max, tc.want)
+                       t.Errorf("(%T).Max(%q, %q) = %q; want %q", reqs, tc.a, tc.b, max, tc.want)
                }
        }
 }