diff --git a/src/cmd/link/internal/loader/loader.go b/src/cmd/link/internal/loader/loader.go index 32c342e545..3df84c5c94 100644 --- a/src/cmd/link/internal/loader/loader.go +++ b/src/cmd/link/internal/loader/loader.go @@ -434,7 +434,17 @@ func (l *Loader) AddSym(name string, ver int, r *oReader, li int, kind int, dupo if l.flags&FlagStrictDups != 0 { l.checkdup(name, r, li, oldi) } - return oldi, false + // Fix for issue #46656 -- given two dupok symbols with + // different sizes, favor symbol with larger size. + szdup := l.SymSize(oldi) + sz := int64(r.Sym(li).Siz()) + if szdup >= sz { + return oldi, false + } else { + // new symbol overwrites old symbol. + l.objSyms[oldi] = objSym{r, li} + return oldi, true + } } oldr, oldli := l.toLocal(oldi) oldsym := oldr.Sym(oldli) diff --git a/test/fixedbugs/issue46653.dir/bad/bad.go b/test/fixedbugs/issue46653.dir/bad/bad.go new file mode 100644 index 0000000000..c1611b8347 --- /dev/null +++ b/test/fixedbugs/issue46653.dir/bad/bad.go @@ -0,0 +1,64 @@ +// Copyright 2021 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package a + +func Bad() { + m := make(map[int64]A) + a := m[0] + if len(a.B.C1.D2.E2.F1) != 0 || + len(a.B.C1.D2.E2.F2) != 0 || + len(a.B.C1.D2.E2.F3) != 0 || + len(a.B.C1.D2.E2.F4) != 0 || + len(a.B.C1.D2.E2.F5) != 0 || + len(a.B.C1.D2.E2.F6) != 0 || + len(a.B.C1.D2.E2.F7) != 0 || + len(a.B.C1.D2.E2.F8) != 0 || + len(a.B.C1.D2.E2.F9) != 0 || + len(a.B.C1.D2.E2.F10) != 0 || + len(a.B.C1.D2.E2.F11) != 0 || + len(a.B.C1.D2.E2.F16) != 0 { + panic("bad") + } +} + +type A struct { + B +} + +type B struct { + C1 C + C2 C +} + +type C struct { + D1 D + D2 D +} + +type D struct { + E1 E + E2 E + E3 E + E4 E +} + +type E struct { + F1 string + F2 string + F3 string + F4 string + F5 string + F6 string + F7 string + F8 string + F9 string + F10 string + F11 string + F12 string + F13 string + F14 string + F15 string + F16 string +} diff --git a/test/fixedbugs/issue46653.dir/main.go b/test/fixedbugs/issue46653.dir/main.go new file mode 100644 index 0000000000..e2a96e54ec --- /dev/null +++ b/test/fixedbugs/issue46653.dir/main.go @@ -0,0 +1,27 @@ +// Copyright 2021 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package main + +import ( + bad "issue46653.dir/bad" +) + +func main() { + bad.Bad() +} + +func neverCalled() L { + m := make(map[string]L) + return m[""] +} + +type L struct { + A Data + B Data +} + +type Data struct { + F1 [22][]string +} diff --git a/test/fixedbugs/issue46653.go b/test/fixedbugs/issue46653.go new file mode 100644 index 0000000000..e6283b1de5 --- /dev/null +++ b/test/fixedbugs/issue46653.go @@ -0,0 +1,10 @@ +// runindir + +// Copyright 2021 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Test to verify compiler and linker handling of multiple +// competing map.zero symbol definitions. + +package ignored