| Message ID | 20200303201301.GC2156@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | inliner: Copy DECL_BY_REFERENCE in copy_decl_to_var [PR93888] | expand |
On March 3, 2020 9:13:01 PM GMT+01:00, Jakub Jelinek <jakub@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 <jakub@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
--- 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); +}