diff options
Diffstat (limited to 'src/cmd/go/internal/modload/buildlist.go')
| -rw-r--r-- | src/cmd/go/internal/modload/buildlist.go | 68 |
1 files changed, 60 insertions, 8 deletions
diff --git a/src/cmd/go/internal/modload/buildlist.go b/src/cmd/go/internal/modload/buildlist.go index 777e29af10..da9e6406b1 100644 --- a/src/cmd/go/internal/modload/buildlist.go +++ b/src/cmd/go/internal/modload/buildlist.go @@ -591,7 +591,7 @@ func updateRoots(ctx context.Context, direct map[string]bool, rs *Requirements, // selected at the same version or is upgraded by the dependencies of a // root. // -// If any module that provided a package has been upgraded above its previous, +// If any module that provided a package has been upgraded above its previous // version, the caller may need to reload and recompute the package graph. // // To ensure that the loading process eventually converges, the caller should @@ -980,17 +980,37 @@ func spotCheckRoots(ctx context.Context, rs *Requirements, mods map[module.Versi return true } -// tidyUnprunedRoots returns a minimal set of root requirements that maintains the -// selected version of every module that provided a package in pkgs, and -// includes the selected version of every such module in direct as a root. +// tidyUnprunedRoots returns a minimal set of root requirements that maintains +// the selected version of every module that provided or lexically could have +// provided a package in pkgs, and includes the selected version of every such +// module in direct as a root. func tidyUnprunedRoots(ctx context.Context, mainModule module.Version, direct map[string]bool, pkgs []*loadPkg) (*Requirements, error) { var ( + // keep is a set of of modules that provide packages or are needed to + // disambiguate imports. keep []module.Version keptPath = map[string]bool{} - ) - var ( - rootPaths []string // module paths that should be included as roots + + // rootPaths is a list of module paths that provide packages directly + // imported from the main module. They should be included as roots. + rootPaths []string inRootPaths = map[string]bool{} + + // altMods is a set of paths of modules that lexically could have provided + // imported packages. It may be okay to remove these from the list of + // explicit requirements if that removes them from the module graph. If they + // are present in the module graph reachable from rootPaths, they must not + // be at a lower version. That could cause a missing sum error or a new + // import ambiguity. + // + // For example, suppose a developer rewrites imports from example.com/m to + // example.com/m/v2, then runs 'go mod tidy'. Tidy may delete the + // requirement on example.com/m if there is no other transitive requirement + // on it. However, if example.com/m were downgraded to a version not in + // go.sum, when package example.com/m/v2/p is loaded, we'd get an error + // trying to disambiguate the import, since we can't check example.com/m + // without its sum. See #47738. + altMods = map[string]string{} ) for _, pkg := range pkgs { if !pkg.fromExternalModule() { @@ -1004,12 +1024,44 @@ func tidyUnprunedRoots(ctx context.Context, mainModule module.Version, direct ma inRootPaths[m.Path] = true } } + for _, m := range pkg.altMods { + altMods[m.Path] = m.Version + } } - min, err := mvs.Req(mainModule, rootPaths, &mvsReqs{roots: keep}) + // Construct a build list with a minimal set of roots. + // This may remove or downgrade modules in altMods. + reqs := &mvsReqs{roots: keep} + min, err := mvs.Req(mainModule, rootPaths, reqs) + if err != nil { + return nil, err + } + buildList, err := mvs.BuildList([]module.Version{mainModule}, reqs) if err != nil { return nil, err } + + // Check if modules in altMods were downgraded but not removed. + // If so, add them to roots, which will retain an "// indirect" requirement + // in go.mod. See comment on altMods above. + keptAltMod := false + for _, m := range buildList { + if v, ok := altMods[m.Path]; ok && semver.Compare(m.Version, v) < 0 { + keep = append(keep, module.Version{Path: m.Path, Version: v}) + keptAltMod = true + } + } + if keptAltMod { + // We must run mvs.Req again instead of simply adding altMods to min. + // It's possible that a requirement in altMods makes some other + // explicit indirect requirement unnecessary. + reqs.roots = keep + min, err = mvs.Req(mainModule, rootPaths, reqs) + if err != nil { + return nil, err + } + } + return newRequirements(unpruned, min, direct), nil } |