mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2025-02-23 13:21:43 +08:00
6740f0cc3b
I have come across some uses cases where it would be desirable to treat
an enum that has duplicate values as a "flag enum". For example, this
one here [1]:
enum membarrier_cmd {
MEMBARRIER_CMD_QUERY = 0,
MEMBARRIER_CMD_GLOBAL = (1 << 0),
MEMBARRIER_CMD_GLOBAL_EXPEDITED = (1 << 1),
MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED = (1 << 2),
MEMBARRIER_CMD_PRIVATE_EXPEDITED = (1 << 3),
MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED = (1 << 4),
MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE = (1 << 5),
MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE = (1 << 6),
/* Alias for header backward compatibility. */
MEMBARRIER_CMD_SHARED = MEMBARRIER_CMD_GLOBAL,
};
The last enumerator is kept for backwards compatibility. Without this
patch, this enumeration wouldn't be considered a flag enum, because two
enumerators collide. With this patch, it would be considered a flag
enum, and the value 3 would be printed as:
MEMBARRIER_CMD_GLOBAL | MEMBARRIER_CMD_GLOBAL_EXPEDITED
Although if people prefer, we could display both MEMBARRIER_CMD_GLOBAL
and MEMBARRIER_CMD_SHARED in the result. It wouldn't be wrong, and
could perhaps be useful in case a bit may have multiple meanings
(depending on some other bit value).
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/membarrier.h?id=0bf999f9c5e74c7ecf9dafb527146601e5c848b9#n125
gdb/ChangeLog:
* dwarf2/read.c (update_enumeration_type_from_children): Allow
flag enums to contain duplicate enumerators.
* valprint.c (generic_val_print_enum_1): Update comment.
gdb/testsuite/ChangeLog:
* gdb.base/printcmds.c (enum flag_enum): Add FE_TWO_LEGACY
enumerator.
|
||
|---|---|---|
| .. | ||
| abbrev.c | ||
| abbrev.h | ||
| attribute.c | ||
| attribute.h | ||
| comp-unit.c | ||
| comp-unit.h | ||
| expr.c | ||
| expr.h | ||
| frame-tailcall.c | ||
| frame-tailcall.h | ||
| frame.c | ||
| frame.h | ||
| index-cache.c | ||
| index-cache.h | ||
| index-common.c | ||
| index-common.h | ||
| index-write.c | ||
| index-write.h | ||
| leb.c | ||
| leb.h | ||
| line-header.c | ||
| line-header.h | ||
| loc.c | ||
| loc.h | ||
| read.c | ||
| read.h | ||
| section.c | ||
| section.h | ||