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| author | Tom Tromey <tom@tromey.com> | 2018-08-17 20:34:40 -0600 |
|---|---|---|
| committer | Tom Tromey <tom@tromey.com> | 2018-10-03 15:19:06 -0600 |
| commit | 1dffa580e7e083a43216fd7cbcadd72c760cf29d (patch) | |
| tree | 9bdaf55505d364a7e095dd10296552e58e820ff5 /gdb/expression.h | |
| parent | 5e70ee0905a848701bb929a66f84ff2e212cfa81 (diff) | |
| download | gdb-1dffa580e7e083a43216fd7cbcadd72c760cf29d.zip gdb-1dffa580e7e083a43216fd7cbcadd72c760cf29d.tar.gz gdb-1dffa580e7e083a43216fd7cbcadd72c760cf29d.tar.bz2 | |
Avoid undefined behavior in expression dumping
-fsanitize=undefined pointed out undefined behavior in
dump_raw_expression like:
runtime error: load of value 2887952, which is not a valid value for type 'exp_opcode'
dump_raw_expression will try to print the opcode for each element of
the expression, even when it is not valid. To allow this, but have it
avoid undefined behavior, this patch sets the underlying type of enum
exp_opcode, and arranges for op_name to handle invalid opcodes more
nicely.
Before this patch, debug-expr.exp shows:
Dump of expression @ 0x60f000007750, before conversion to prefix form:
Language c, 8 elements, 16 bytes each.
Index Opcode Hex Value String Value
0 OP_TYPE 89 Y...............
<unknown 3851920> 107820862850704 ..:..b..........
2 OP_TYPE 89 Y...............
3 OP_VAR_VALUE 40 (...............
4 <unknown 2807568> 107820861806352 ..*..b..........
5 <unknown 2806368> 107820861805152 `.*..b..........
6 OP_VAR_VALUE 40 (...............
7 UNOP_MEMVAL_TYPE 57 9...............
Afterward, the output is:
Dump of expression @ 0x4820f90, before conversion to prefix form:
Language c, 8 elements, 16 bytes each.
Index Opcode Hex Value String Value
0 OP_TYPE 89 Y...............
1 unknown opcode: 176 75444400 .0..............
2 OP_TYPE 89 Y...............
3 OP_VAR_VALUE 40 (...............
4 OP_BOOL 74616912 P.r.............
5 unknown opcode: 128 74615680 ..r.............
6 OP_VAR_VALUE 40 (...............
7 UNOP_MEMVAL_TYPE 57 9...............
gdb/ChangeLog
2018-10-03 Tom Tromey <tom@tromey.com>
* expression.h (enum exp_opcode): Use uint8_t as base type.
* expprint.c (op_name): Handle invalid opcodes.
Diffstat (limited to 'gdb/expression.h')
| -rw-r--r-- | gdb/expression.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/gdb/expression.h b/gdb/expression.h index bc7625f..a5cb4c6 100644 --- a/gdb/expression.h +++ b/gdb/expression.h @@ -39,7 +39,7 @@ and skip that many. Strings, like numbers, are indicated by the preceding opcode. */ -enum exp_opcode +enum exp_opcode : uint8_t { #define OP(name) name , |