Avoid crash in Ada value printing with optimized-out array

The Ada value-printing code could crash when printing an array which
had been optimized out.

The crash is difficult to reproduce, but I did manage to write a test
that at least shows that the previous behavior was incorrect -- before
the patch, the array is printed as if it is valid and every value is 0.

gdb/ChangeLog
2021-04-15  Tom Tromey  <tromey@adacore.com>

	* ada-valprint.c (ada_value_print_array): Handle optimized-out
	arrays.

gdb/testsuite/ChangeLog
2021-04-15  Tom Tromey  <tromey@adacore.com>

	* gdb.dwarf2/arr-stride.exp: Add test.
This commit is contained in:
Tom Tromey 2021-04-15 10:14:11 -06:00
parent 644a2e75ac
commit a15a276b46
4 changed files with 45 additions and 2 deletions

View File

@ -1,3 +1,8 @@
2021-04-15 Tom Tromey <tromey@adacore.com>
* ada-valprint.c (ada_value_print_array): Handle optimized-out
arrays.
2021-04-15 Tom Tromey <tromey@adacore.com>
* printcmd.c (print_variable_and_value): Use

View File

@ -897,7 +897,10 @@ ada_value_print_array (struct value *val, struct ui_file *stream, int recurse,
fprintf_filtered (stream, "(");
print_optional_low_bound (stream, type, options);
if (TYPE_FIELD_BITSIZE (type, 0) > 0)
if (value_entirely_optimized_out (val))
val_print_optimized_out (val, stream);
else if (TYPE_FIELD_BITSIZE (type, 0) > 0)
{
const gdb_byte *valaddr = value_contents_for_printing (val);
int offset_aligned = ada_aligned_value_addr (type, valaddr) - valaddr;

View File

@ -1,3 +1,7 @@
2021-04-15 Tom Tromey <tromey@adacore.com>
* gdb.dwarf2/arr-stride.exp: Add test.
2021-04-15 Andrew Burgess <andrew.burgess@embecosm.com>
* gdb.base/startup-file.exp: Add more tests.

View File

@ -31,7 +31,7 @@ Dwarf::assemble $asm_file {
{DW_AT_comp_dir /tmp}
} {
declare_labels integer_label array_elt_label array_label \
big_array_label
big_array_label struct_label
integer_label: DW_TAG_base_type {
{DW_AT_byte_size 4 DW_FORM_sdata}
@ -79,6 +79,34 @@ Dwarf::assemble $asm_file {
{DW_AT_upper_bound 4 DW_FORM_data1}
}
}
struct_label: DW_TAG_structure_type {
{name struct_type}
{byte_size 16 DW_FORM_sdata}
} {
member {
{name intfield}
{type :$integer_label}
{data_member_location 0 DW_FORM_sdata}
}
member {
{name arrayfield}
{type :$array_label}
{data_member_location 4 DW_FORM_sdata}
}
}
DW_TAG_variable {
{name the_struct}
{external 1 DW_FORM_flag}
{location {
DW_OP_const1u 1
DW_OP_stack_value
DW_OP_piece 4
DW_OP_piece 12
} SPECIAL_expr}
{type :$struct_label}
}
}
}
}
@ -95,3 +123,6 @@ gdb_test "ptype pck.table" \
gdb_test "ptype pck.big_table" \
"type = array \\(0 \\.\\. 4\\) of pck\\.item <packed: 8-bit elements>"
gdb_test "print the_struct" \
"\\(intfield => 1, arrayfield => \\(0 => <optimized out>\\)\\)"