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?
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
