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| author | David Howells <dhowells@redhat.com> | 2018-09-06 12:19:24 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2018-10-17 23:56:54 +0300 |
| commit | 9607871f37dc3e717639694b8d0dc738f2a68efc (patch) | |
| tree | a794e8920d636d4ea86e2e9eb31b1b57f6c80167 | |
| parent | f110176633d74bbac1f80ab9b9c6b83ea3e1cc23 (diff) | |
| download | linux-9607871f37dc3e717639694b8d0dc738f2a68efc.tar.xz | |
UAPI: ndctl: Fix g++-unsupported initialisation in headers
The following code in the linux/ndctl header file:
static inline const char *nvdimm_bus_cmd_name(unsigned cmd)
{
static const char * const names[] = {
[ND_CMD_ARS_CAP] = "ars_cap",
[ND_CMD_ARS_START] = "ars_start",
[ND_CMD_ARS_STATUS] = "ars_status",
[ND_CMD_CLEAR_ERROR] = "clear_error",
[ND_CMD_CALL] = "cmd_call",
};
if (cmd < ARRAY_SIZE(names) && names[cmd])
return names[cmd];
return "unknown";
}
is broken in a number of ways:
(1) ARRAY_SIZE() is not generally defined.
(2) g++ does not support "non-trivial" array initialisers fully yet.
(3) Every file that calls this function will acquire a copy of names[].
The same goes for nvdimm_cmd_name().
Fix all three by converting to a switch statement where each case returns a
string. That way if cmd is a constant, the compiler can trivially reduce it
and, if not, the compiler can use a shared lookup table if it thinks that is
more efficient.
A better way would be to remove these functions and their arrays from the
header entirely.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| -rw-r--r-- | include/uapi/linux/ndctl.h | 48 |
1 files changed, 21 insertions, 27 deletions
diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h index 7e27070b9440..2f2c43d633c5 100644 --- a/include/uapi/linux/ndctl.h +++ b/include/uapi/linux/ndctl.h @@ -128,37 +128,31 @@ enum { static inline const char *nvdimm_bus_cmd_name(unsigned cmd) { - static const char * const names[] = { - [ND_CMD_ARS_CAP] = "ars_cap", - [ND_CMD_ARS_START] = "ars_start", - [ND_CMD_ARS_STATUS] = "ars_status", - [ND_CMD_CLEAR_ERROR] = "clear_error", - [ND_CMD_CALL] = "cmd_call", - }; - - if (cmd < ARRAY_SIZE(names) && names[cmd]) - return names[cmd]; - return "unknown"; + switch (cmd) { + case ND_CMD_ARS_CAP: return "ars_cap"; + case ND_CMD_ARS_START: return "ars_start"; + case ND_CMD_ARS_STATUS: return "ars_status"; + case ND_CMD_CLEAR_ERROR: return "clear_error"; + case ND_CMD_CALL: return "cmd_call"; + default: return "unknown"; + } } static inline const char *nvdimm_cmd_name(unsigned cmd) { - static const char * const names[] = { - [ND_CMD_SMART] = "smart", - [ND_CMD_SMART_THRESHOLD] = "smart_thresh", - [ND_CMD_DIMM_FLAGS] = "flags", - [ND_CMD_GET_CONFIG_SIZE] = "get_size", - [ND_CMD_GET_CONFIG_DATA] = "get_data", - [ND_CMD_SET_CONFIG_DATA] = "set_data", - [ND_CMD_VENDOR_EFFECT_LOG_SIZE] = "effect_size", - [ND_CMD_VENDOR_EFFECT_LOG] = "effect_log", - [ND_CMD_VENDOR] = "vendor", - [ND_CMD_CALL] = "cmd_call", - }; - - if (cmd < ARRAY_SIZE(names) && names[cmd]) - return names[cmd]; - return "unknown"; + switch (cmd) { + case ND_CMD_SMART: return "smart"; + case ND_CMD_SMART_THRESHOLD: return "smart_thresh"; + case ND_CMD_DIMM_FLAGS: return "flags"; + case ND_CMD_GET_CONFIG_SIZE: return "get_size"; + case ND_CMD_GET_CONFIG_DATA: return "get_data"; + case ND_CMD_SET_CONFIG_DATA: return "set_data"; + case ND_CMD_VENDOR_EFFECT_LOG_SIZE: return "effect_size"; + case ND_CMD_VENDOR_EFFECT_LOG: return "effect_log"; + case ND_CMD_VENDOR: return "vendor"; + case ND_CMD_CALL: return "cmd_call"; + default: return "unknown"; + } } #define ND_IOCTL 'N' |