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| author | Simon Marchi <simon.marchi@efficios.com> | 2020-02-18 17:29:23 -0500 |
|---|---|---|
| committer | Simon Marchi <simon.marchi@efficios.com> | 2020-02-18 17:32:57 -0500 |
| commit | 6740f0cc3bd1530e4aeefe856d9cfe5c0ba2098a (patch) | |
| tree | 479be063e13d06ad978b4c29772debda946c2d49 /gdb/dwarf2 | |
| parent | edd45eb06bfc4683922c6877589004632e6e6d29 (diff) | |
| download | gdb-6740f0cc3bd1530e4aeefe856d9cfe5c0ba2098a.zip gdb-6740f0cc3bd1530e4aeefe856d9cfe5c0ba2098a.tar.gz gdb-6740f0cc3bd1530e4aeefe856d9cfe5c0ba2098a.tar.bz2 | |
gdb: allow duplicate enumerators in flag enums
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.
Diffstat (limited to 'gdb/dwarf2')
| -rw-r--r-- | gdb/dwarf2/read.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index 5a77b62..ee220ab 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -15495,7 +15495,6 @@ update_enumeration_type_from_children (struct die_info *die, struct die_info *child_die; int unsigned_enum = 1; int flag_enum = 1; - ULONGEST mask = 0; auto_obstack obstack; @@ -15531,10 +15530,6 @@ update_enumeration_type_from_children (struct die_info *die, { if (count_one_bits_ll (value) >= 2) flag_enum = 0; - else if ((mask & value) != 0) - flag_enum = 0; - else - mask |= value; } /* If we already know that the enum type is neither unsigned, nor |