diff options
| -rw-r--r-- | src/cmd/compile/internal/gc/dwinl.go | 3 | ||||
| -rw-r--r-- | test/fixedbugs/issue44378.go | 40 |
2 files changed, 42 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/gc/dwinl.go b/src/cmd/compile/internal/gc/dwinl.go index bb5ae61cbb..31d076814c 100644 --- a/src/cmd/compile/internal/gc/dwinl.go +++ b/src/cmd/compile/internal/gc/dwinl.go @@ -243,7 +243,8 @@ func makePreinlineDclMap(fnsym *obj.LSym) map[varPos]int { DeclCol: pos.Col(), } if _, found := m[vp]; found { - Fatalf("child dcl collision on symbol %s within %v\n", n.Sym.Name, fnsym.Name) + // We can see collisions (variables with the same name/file/line/col) in obfuscated or machine-generated code -- see issue 44378 for an example. Skip duplicates in such cases, since it is unlikely that a human will be debugging such code. + continue } m[vp] = i } diff --git a/test/fixedbugs/issue44378.go b/test/fixedbugs/issue44378.go new file mode 100644 index 0000000000..58c88d573f --- /dev/null +++ b/test/fixedbugs/issue44378.go @@ -0,0 +1,40 @@ +// compile + +// 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. + +// This test case caused a panic in the compiler's DWARF gen code. + +// Note to future maintainers of this code: +// +// ** Do NOT run gofmt when editing this file ** +// +// In order for the buggy behavior to be triggered in the compiler, +// we need to have a the function of interest all on one gigantic line. + +package a + +type O interface{} +type IO int +type OS int + +type A struct { + x int +} + +// original versions of the two function +func (p *A) UO(o O) { + p.r(o, o) +} +func (p *A) r(o1, o2 O) { + switch x := o1.(type) { + case *IO: + p.x = int(*x) + case *OS: + p.x = int(*x + 2) + } +} + +// see note above about the importance of all this code winding up on one line. +var myverylongname0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789 int ; func (p *A) UO2(o O) { p.r2(o, o); }; func (p *A) r2(o1, o2 O) { switch x := o1.(type) { case *IO: p.x = int(*x); case *OS: p.x = int(*x + 2); } } |