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author | Robert Griesemer <gri@golang.org> | 2019-06-25 15:46:23 -0700 |
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committer | Robert Griesemer <gri@golang.org> | 2019-06-26 03:59:57 +0000 |
commit | adf888376deb749bc95a2717989eb0f2db001f8d (patch) | |
tree | 4820316c80546bb1094b7368017e101a6558095e | |
parent | 6d1aaf143c879ae7acbd20a1e60bf74681bf6055 (diff) | |
download | go-adf888376deb749bc95a2717989eb0f2db001f8d.tar.gz go-adf888376deb749bc95a2717989eb0f2db001f8d.zip |
go/types: avoid race condition with dot-imported objects
It would be nice to have a test, but it requires running
this under the race detector which is a bit complicated
to set up; yet the fix is trivial. Verified manually that
it doesn't trip the race detector.
Fixes #32154.
Change-Id: I20bd746a07945c802f0476a1d8b1dfd83c87dae8
Reviewed-on: https://go-review.googlesource.com/c/go/+/183849
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
-rw-r--r-- | src/go/types/resolver.go | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/src/go/types/resolver.go b/src/go/types/resolver.go index 41741e5882..417e4e79aa 100644 --- a/src/go/types/resolver.go +++ b/src/go/types/resolver.go @@ -301,15 +301,15 @@ func (check *Checker) collectObjects() { // A package scope may contain non-exported objects, // do not import them! if obj.Exported() { - // TODO(gri) When we import a package, we create - // a new local package object. We should do the - // same for each dot-imported object. That way - // they can have correct position information. - // (We must not modify their existing position - // information because the same package - found - // via Config.Packages - may be dot-imported in - // another package!) - check.declare(fileScope, nil, obj, token.NoPos) + // declare dot-imported object + // (Do not use check.declare because it modifies the object + // via Object.setScopePos, which leads to a race condition; + // the object may be imported into more than one file scope + // concurrently. See issue #32154.) + if alt := fileScope.Insert(obj); alt != nil { + check.errorf(s.Name.Pos(), "%s redeclared in this block", obj.Name()) + check.reportAltDecl(alt) + } } } // add position to set of dot-import positions for this file @@ -317,6 +317,7 @@ func (check *Checker) collectObjects() { check.addUnusedDotImport(fileScope, imp, s.Pos()) } else { // declare imported package object in file scope + // (no need to provide s.Name since we called check.recordDef earlier) check.declare(fileScope, nil, obj, token.NoPos) } |