tree df058c589c99b24e278791c797cbf1e62b4c6dd0
parent f3c699f2ac08b9e45954bae7a4b4b2baf2457516
author Than McIntosh <thanm@google.com> 1613165712 -0500
committer Than McIntosh <thanm@google.com> 1613241780 +0000

gollvm: fix buglet in llvm-godumpspec

The code in llvm-godumpspec that inspects DWARF type information was
not allowing for the possibility of a benign "duplicate but identical"
typedef in C (allowed as a GNU extension). For example, it is possible
to see the following typedef

   typedef __gnuc_va_list va_list;

in both stdio.h and stdarg.h. Interestingly enough this can also
generated two DWARF entries (surprisingly), so to handle this scenario
in llvm-godumpspec, suppress the emission of a named type if we have
already emitted a type of the same name.

Updates golang/go#44223.

Change-Id: Idc3570c9905efa6c24f00c53a56645864218d1cd
Reviewed-on: https://go-review.googlesource.com/c/gollvm/+/291610
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: Than McIntosh <thanm@google.com>