cmd/go: force -coverpkg main packages to be built as libraries

Jay Conrod · Jay Conrod · commit 3b8c804164e2 · 2019-05-10T16:28:38.000Z
This fixes TestScript/cover_pkgall_multiple_mains, which started failing after CL 174657. When compiling main packages with coverage instrumentation (e.g., for -coverpkg all), we now pass -p with the full import path instead of '-p main'. This avoids link errors 'duplicate symbol main.main (types 1 and 1)'. Fixes #31946 Change-Id: Id147527b1dbdc14bb33ac133c30d50c250b4365c Reviewed-on: https://go-review.googlesource.com/c/go/+/176558 Run-TryBot: Jay Conrod <jayconrod@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Bryan C. Mills <bcmills@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/src/cmd/go/internal/load/test.go b/src/cmd/go/internal/load/test.go
@@ -353,9 +353,10 @@ Search:
 // preal, packages that import the package under test should get ptest instead
 // of preal. This is particularly important if pxtest depends on functionality
 // exposed in test sources in ptest. Second, if there is a main package
-// (other than pmain) anywhere, we need to clear p.Internal.BuildInfo in
-// the test copy to prevent link conflicts. This may happen if both -coverpkg
-// and the command line patterns include multiple main packages.
+// (other than pmain) anywhere, we need to set p.Internal.ForceLibrary and
+// clear p.Internal.BuildInfo in the test copy to prevent link conflicts.
+// This may happen if both -coverpkg and the command line patterns include
+// multiple main packages.
 func recompileForTest(pmain, preal, ptest, pxtest *Package) {
 	// The "test copy" of preal is ptest.
 	// For each package that depends on preal, make a "test copy"
@@ -386,6 +387,7 @@ func recompileForTest(pmain, preal, ptest, pxtest *Package) {
 			p = p1
 			p.Target = ""
 			p.Internal.BuildInfo = ""
+			p.Internal.ForceLibrary = true
 		}
 
 		// Update p.Internal.Imports to use test copies.
