On March 3, 2020 9:13:01 PM GMT+01:00, Jakub Jelinek <ja...@redhat.com> wrote:
>Hi!
>
>In the following testcase we emit wrong debug info for the karg
>parameter in the DW_TAG_inlined_subroutine into main.
>The problem is that the karg PARM_DECL is DECL_BY_REFERENCE and thus
>in the IL has const K & type, but in the source just const K.
>When the function is inlined, we create a VAR_DECL for it, but don't
>set DECL_BY_REFERENCE, so when emitting DW_AT_location, we treat it
>like
>a const K & typed variable, but it has DW_AT_abstract_origin which has
>just the const K type and thus the debugger thinks the variable has
>const K type.
>
>Fixed by copying the DECL_BY_REFERENCE flag. Not doing it in
>copy_decl_for_dup_finish, because copy_decl_no_change already copies
>that flag through copy_node and in copy_result_decl_to_var it is
>undesirable, as we handle DECL_BY_REFERENCE in that case instead
>by changing the type.
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok.
Richard.
>2020-03-03 Jakub Jelinek <ja...@redhat.com>
>
> PR debug/93888
> * tree-inline.c (copy_decl_to_var): Copy DECL_BY_REFERENCE flag.
>
> * g++.dg/guality/pr93888.C: New test.
>
>--- gcc/tree-inline.c.jj 2020-02-07 19:11:57.444981885 +0100
>+++ gcc/tree-inline.c 2020-03-03 13:27:57.811046011 +0100
>@@ -5929,6 +5929,7 @@ copy_decl_to_var (tree decl, copy_body_d
> TREE_READONLY (copy) = TREE_READONLY (decl);
> TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (decl);
> DECL_GIMPLE_REG_P (copy) = DECL_GIMPLE_REG_P (decl);
>+ DECL_BY_REFERENCE (copy) = DECL_BY_REFERENCE (decl);
>
> return copy_decl_for_dup_finish (id, decl, copy);
> }
>--- gcc/testsuite/g++.dg/guality/pr93888.C.jj 2020-03-03
>13:38:16.273935942 +0100
>+++ gcc/testsuite/g++.dg/guality/pr93888.C 2020-03-03
>13:40:15.890174469 +0100
>@@ -0,0 +1,24 @@
>+// PR debug/93888
>+// { dg-do run }
>+// { dg-options "-g -fvar-tracking -fno-inline" }
>+// { dg-skip-if "" { *-*-* } { "*" } { "-O0" } }
>+
>+struct K
>+{
>+ K () {}
>+ K (K const &rhs) { k[0] = 'C'; }
>+ char k[8] = {'B','B','B','B','B','B','B','B'};
>+};
>+
>+__attribute__((always_inline)) inline bool
>+foo (const K karg)
>+{
>+ return karg.k[0] != 'C'; // { dg-final { gdb-test 16 "karg.k[0]"
>"'C'" } }
>+} // { dg-final { gdb-test 16 "karg.k[1]" "'B'" }
>}
>+
>+int
>+main ()
>+{
>+ K x;
>+ return foo (x);
>+}
>
> Jakub
