[v2,11/19] Add DWARF piece test cases for bit-field access
Commit Message
This verifies some of the previous fixes to the logic in
write_pieced_value when accessing bit-fields.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/var-access.exp: Add tests for accessing bit-fields
located in one or more DWARF pieces.
---
gdb/testsuite/gdb.dwarf2/var-access.exp | 81 ++++++++++++++++++++++++++++++++-
1 file changed, 80 insertions(+), 1 deletion(-)
Comments
Andreas Arnez <arnez@linux.vnet.ibm.com> writes:
> gdb/testsuite/ChangeLog:
>
> * gdb.dwarf2/var-access.exp: Add tests for accessing bit-fields
> located in one or more DWARF pieces.
LGTM.
@@ -62,7 +62,8 @@ Dwarf::assemble $asm_file {
} {
declare_labels char_type_label
declare_labels int_type_label short_type_label
- declare_labels array_a8_label struct_s_label
+ declare_labels array_a8_label struct_s_label struct_t_label
+ declare_labels struct_st_label
# char
char_type_label: base_type {
@@ -115,6 +116,51 @@ Dwarf::assemble $asm_file {
}
}
+ # struct t { int u, x:9, y:13, z:10; };
+ struct_t_label: structure_type {
+ {name "t"}
+ {byte_size 8 DW_FORM_sdata}
+ } {
+ member {
+ {name "u"}
+ {type :$int_type_label}
+ }
+ member {
+ {name "x"}
+ {type :$int_type_label}
+ {data_member_location 4 DW_FORM_udata}
+ {bit_size 9 DW_FORM_udata}
+ }
+ member {
+ {name "y"}
+ {type :$int_type_label}
+ {data_bit_offset 41 DW_FORM_udata}
+ {bit_size 13 DW_FORM_udata}
+ }
+ member {
+ {name "z"}
+ {type :$int_type_label}
+ {data_bit_offset 54 DW_FORM_udata}
+ {bit_size 10 DW_FORM_udata}
+ }
+ }
+
+ # struct st { struct s s; struct t t; };
+ struct_st_label: structure_type {
+ {name "st"}
+ {byte_size 12 DW_FORM_udata}
+ } {
+ member {
+ {name "s"}
+ {type :$struct_s_label}
+ }
+ member {
+ {name "t"}
+ {type :$struct_t_label}
+ {data_member_location 4 DW_FORM_udata}
+ }
+ }
+
DW_TAG_subprogram {
{MACRO_AT_func { main ${srcdir}/${subdir}/${srcfile} }}
{DW_AT_external 1 flag}
@@ -156,6 +202,19 @@ Dwarf::assemble $asm_file {
piece 1
} SPECIAL_expr}
}
+ # Memory pieces for bitfield access: 8 bytes optimized
+ # out, 3 bytes from &buf[3], and 1 byte from &buf[1].
+ DW_TAG_variable {
+ {name "st1"}
+ {type :$struct_st_label}
+ {location {
+ piece 8
+ addr "$buf_var + 3"
+ piece 3
+ addr "$buf_var + 1"
+ piece 1
+ } SPECIAL_expr}
+ }
}
}
}
@@ -170,6 +229,9 @@ if ![runto_main] {
return -1
}
+# Determine byte order.
+set endian [get_endianness]
+
# Byte-aligned memory pieces.
gdb_test "print/d s1" " = \\{a = 2, b = 3, c = 0, d = 1\\}" \
"s1 == re-ordered buf"
@@ -200,3 +262,20 @@ gdb_test_no_output "set var s2 = {191, 73, 231, 123}" \
"re-initialize s2"
gdb_test "print/d s2" " = \\{a = 191, b = 73, c = 231, d = 123\\}" \
"verify re-initialized s2"
+
+# Unaligned bitfield access through byte-aligned pieces.
+gdb_test_no_output "set var a = { 0 }"
+gdb_test_no_output "set var st1.t.x = -7"
+gdb_test_no_output "set var st1.t.z = 340"
+gdb_test_no_output "set var st1.t.y = 1234"
+gdb_test "print st1.t" " = \\{u = <optimized out>, x = -7, y = 1234, z = 340\\}" \
+ "verify st1.t"
+switch $endian {
+ little {set val "0x55, 0x0, 0xf9, 0xa5, 0x9"}
+ big {set val "0x54, 0x0, 0xfc, 0x93, 0x49"}
+}
+# | -- | z:2-9 | -- | x:0-7 | x:8 y:0-6 | y:7-12 z:0-1 | -- | -- |
+# \_______________________________________________/
+# val
+gdb_test "print/x a" " = \\{0x0, ${val}, 0x0, 0x0\\}" \
+ "verify st1 through a"