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author | Simon Marchi <simon.marchi@polymtl.ca> | 2023-01-20 11:41:08 -0500 |
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committer | Simon Marchi <simon.marchi@polymtl.ca> | 2023-01-20 11:41:08 -0500 |
commit | 173628ae6896d4cadddcb0c3034206d7cc9fb19a (patch) | |
tree | 873bd1ee441cbd1132a04bbbd522468c167f82f5 /gdb/dwarf2 | |
parent | ec15b12d0684b41f67b56623f6e9b5024bf08905 (diff) | |
download | gdb-173628ae6896d4cadddcb0c3034206d7cc9fb19a.zip gdb-173628ae6896d4cadddcb0c3034206d7cc9fb19a.tar.gz gdb-173628ae6896d4cadddcb0c3034206d7cc9fb19a.tar.bz2 |
gdb/testsuite: add test for negative subrange bounds with unsigned form
I am looking at this code [1]:
/* Normally, the DWARF producers are expected to use a signed
constant form (Eg. DW_FORM_sdata) to express negative bounds.
But this is unfortunately not always the case, as witnessed
with GCC, for instance, where the ambiguous DW_FORM_dataN form
is used instead. To work around that ambiguity, we treat
the bounds as signed, and thus sign-extend their values, when
the base type is signed. */
negative_mask =
-((ULONGEST) 1 << (base_type->length () * TARGET_CHAR_BIT - 1));
if (low.kind () == PROP_CONST
&& !base_type->is_unsigned () && (low.const_val () & negative_mask))
low.set_const_val (low.const_val () | negative_mask);
if (high.kind () == PROP_CONST
&& !base_type->is_unsigned () && (high.const_val () & negative_mask))
high.set_const_val (high.const_val () | negative_mask);
Nothing in the testsuite seems to exercise it, as when I remove it, all
of gdb.dwarf2 still passes. And tests in other directories would be
compiler-dependent, so would rely on having a buggy compiler.
Update gdb.dwarf2/subrange.exp to have a test for it. When removing the
code above, the new test fails with:
ptype array_with_buggy_negative_bounds_type^M
type = array [240..244] of signed_byte^M
(gdb) FAIL: gdb.dwarf2/subrange.exp: ptype array_with_buggy_negative_bounds_type
instead of the expected:
ptype array_with_buggy_negative_bounds_type^M
type = array [-16..-12] of signed_byte^M
(gdb) PASS: gdb.dwarf2/subrange.exp: ptype array_with_buggy_negative_bounds_type
[1] https://gitlab.com/gnutools/binutils-gdb/-/blob/5ea14aa4e53fa37f4ba4517497ed2c1e4c60dee2/gdb/dwarf2/read.c#L17681-17695
Change-Id: I1992a3ff0cb1e90fa8a9114dae6c591792f059c2
Diffstat (limited to 'gdb/dwarf2')
0 files changed, 0 insertions, 0 deletions