cmd/go/internal/modload: fix sanity check in rawGoModSummary

m.Path is never empty for a module in the build list; this fixes a
typo from CL 334932.

Change-Id: I5328081ba3bcf5eeac9a1b21a03969ba82ab20ab
Reviewed-on: https://go-review.googlesource.com/c/go/+/489076
Auto-Submit: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
Run-TryBot: Bryan Mills <bcmills@google.com>

diff --git a/src/cmd/go/internal/modload/modfile.go b/src/cmd/go/internal/modload/modfile.go
index 59915792addff6293500eb71c6fba7192e77d23f..61dcabafb77aaed99837dc8bd37b459c58b09362 100644 (file)
--- a/src/cmd/go/internal/modload/modfile.go
+++ b/src/cmd/go/internal/modload/modfile.go
@@ -673,10 +673,15 @@ func goModSummary(m module.Version) (*modFileSummary, error) {
 // ignoring all replacements that may apply to m and excludes that may apply to
 // its dependencies.
 //
-// rawGoModSummary cannot be used on the Target module.
+// rawGoModSummary cannot be used on the main module outside of workspace mode.
 func rawGoModSummary(m module.Version) (*modFileSummary, error) {
-       if m.Path == "" && MainModules.Contains(m.Path) {
-               panic("internal error: rawGoModSummary called on the Target module")
+       if m.Version == "" && !inWorkspaceMode() && MainModules.Contains(m.Path) {
+               // Calling rawGoModSummary implies that we are treating m as a module whose
+               // requirements aren't the roots of the module graph and can't be modified.
+               //
+               // If we are not in workspace mode, then the requirements of the main module
+               // are the roots of the module graph and we expect them to be kept consistent.
+               panic("internal error: rawGoModSummary called on a main module")
        }
        return rawGoModSummaryCache.Do(m, func() (*modFileSummary, error) {
                summary := new(modFileSummary)
@@ -724,19 +729,18 @@ var rawGoModSummaryCache par.ErrCache[module.Version, *modFileSummary]
 // rawGoModData returns the content of the go.mod file for module m, ignoring
 // all replacements that may apply to m.
 //
-// rawGoModData cannot be used on the Target module.
+// rawGoModData cannot be used on the main module outside of workspace mode.
 //
 // Unlike rawGoModSummary, rawGoModData does not cache its results in memory.
 // Use rawGoModSummary instead unless you specifically need these bytes.
 func rawGoModData(m module.Version) (name string, data []byte, err error) {
        if m.Version == "" {
-               // m is a replacement module with only a file path.
-
                dir := m.Path
                if !filepath.IsAbs(dir) {
                        if inWorkspaceMode() && MainModules.Contains(m.Path) {
                                dir = MainModules.ModRoot(m)
                        } else {
+                               // m is a replacement module with only a file path.
                                dir = filepath.Join(replaceRelativeTo(), dir)
                        }
                }