From: "Steven Rostedt (Red Hat)" Use a cute little macro trick to keep the names of the trace flags file guaranteed to match the corresponding masks. The macro TRACE_FLAGS is defined as a serious of enum names followed by the string name of the file that matches it. For example: #define TRACE_FLAGS \ C(PRINT_PARENT, "print-parent"), \ C(SYM_OFFSET, "sym-offset"), \ C(SYM_ADDR, "sym-addr"), \ C(VERBOSE, "verbose"), Now we can define the following: #undef C #define C(a, b) TRACE_ITER_##a##_BIT enum trace_iterator_bits { TRACE_FLAGS }; The above creates: enum trace_iterator_bits { TRACE_ITER_PRINT_PARENT_BIT, TRACE_ITER_SYM_OFFSET_BIT, TRACE_ITER_SYM_ADDR_BIT, TRACE_ITER_VERBOSE_BIT, }; Then we can redefine C as: #undef C #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT) enum trace_iterator_flags { TRACE_FLAGS }; Which creates: enum trace_iterator_flags { TRACE_ITER_PRINT_PARENT = (1 << TRACE_ITER_PRINT_PARENT_BIT), TRACE_ITER_SYM_OFFSET = (1 << TRACE_ITER_SYM_OFFSET_BIT), TRACE_ITER_SYM_ADDR = (1 << TRACE_ITER_SYM_ADDR_BIT), TRACE_ITER_VERBOSE = (1 << TRACE_ITER_VERBOSE_BIT), }; Then finally we can create the list of file names: #undef C #define C(a, b) b static const char *trace_options[] = { TRACE_FLAGS NULL }; Which creates: static const char *trace_options[] = { "print-parent", "sym-offset", "sym-addr", "verbose", NULL }; The importance of this is that the strings match the bit index. trace_options[TRACE_ITER_SYM_ADDR_BIT] == "sym-addr" Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 36 +++++------------- kernel/trace/trace.h | 102 +++++++++++++++++++++++---------------------------- 2 files changed, 55 insertions(+), 83 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f2fbf610d20e..e80e380d0238 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -854,34 +854,18 @@ unsigned long nsecs_to_usecs(unsigned long nsecs) return nsecs / 1000; } +/* + * TRACE_FLAGS is defined as a tuple matching bit masks with strings. + * It uses C(a, b) where 'a' is the enum name and 'b' is the string that + * matches it. By defining "C(a, b) b", TRACE_FLAGS becomes a list + * of strings in the order that the enums were defined. + */ +#undef C +#define C(a, b) b + /* These must match the bit postions in trace_iterator_flags */ static const char *trace_options[] = { - "print-parent", - "sym-offset", - "sym-addr", - "verbose", - "raw", - "hex", - "bin", - "block", - "stacktrace", - "trace_printk", - "branch", - "annotate", - "userstacktrace", - "sym-userobj", - "printk-msg-only", - "context-info", - "latency-format", - "sleep-time", - "graph-time", - "record-cmd", - "overwrite", - "disable_on_free", - "irq-info", - "markers", - "function-trace", - "display-graph", + TRACE_FLAGS NULL }; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 31d8395c8dc5..d164845edddd 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -884,65 +884,53 @@ extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf, * positions into trace_flags that controls the output. * * NOTE: These bits must match the trace_options array in - * trace.c. + * trace.c (this macro guarantees it). */ -enum trace_iterator_bits { - TRACE_ITER_PRINT_PARENT_BIT = 0, - TRACE_ITER_SYM_OFFSET_BIT, - TRACE_ITER_SYM_ADDR_BIT, - TRACE_ITER_VERBOSE_BIT, - TRACE_ITER_RAW_BIT, - TRACE_ITER_HEX_BIT, - TRACE_ITER_BIN_BIT, - TRACE_ITER_BLOCK_BIT, - TRACE_ITER_STACKTRACE_BIT, - TRACE_ITER_PRINTK_BIT, - TRACE_ITER_BRANCH_BIT, - TRACE_ITER_ANNOTATE_BIT, - TRACE_ITER_USERSTACKTRACE_BIT, - TRACE_ITER_SYM_USEROBJ_BIT, - TRACE_ITER_PRINTK_MSGONLY_BIT, - TRACE_ITER_CONTEXT_INFO_BIT, /* Print pid/cpu/time */ - TRACE_ITER_LATENCY_FMT_BIT, - TRACE_ITER_SLEEP_TIME_BIT, - TRACE_ITER_GRAPH_TIME_BIT, - TRACE_ITER_RECORD_CMD_BIT, - TRACE_ITER_OVERWRITE_BIT, - TRACE_ITER_STOP_ON_FREE_BIT, - TRACE_ITER_IRQ_INFO_BIT, - TRACE_ITER_MARKERS_BIT, - TRACE_ITER_FUNCTION_BIT, - TRACE_ITER_DISPLAY_GRAPH_BIT, -}; +#define TRACE_FLAGS \ + C(PRINT_PARENT, "print-parent"), \ + C(SYM_OFFSET, "sym-offset"), \ + C(SYM_ADDR, "sym-addr"), \ + C(VERBOSE, "verbose"), \ + C(RAW, "raw"), \ + C(HEX, "hex"), \ + C(BIN, "bin"), \ + C(BLOCK, "block"), \ + C(STACKTRACE, "stacktrace"), \ + C(PRINTK, "trace_printk"), \ + C(BRANCH, "branch"), \ + C(ANNOTATE, "annotate"), \ + C(USERSTACKTRACE, "userstacktrace"), \ + C(SYM_USEROBJ, "sym-userobj"), \ + C(PRINTK_MSGONLY, "printk-msg-only"), \ + C(CONTEXT_INFO, "context-info"), /* Print pid/cpu/time */ \ + C(LATENCY_FMT, "latency-format"), \ + C(SLEEP_TIME, "sleep-time"), \ + C(GRAPH_TIME, "graph-time"), \ + C(RECORD_CMD, "record-cmd"), \ + C(OVERWRITE, "overwrite"), \ + C(STOP_ON_FREE, "disable_on_free"), \ + C(IRQ_INFO, "irq-info"), \ + C(MARKERS, "markers"), \ + C(FUNCTION, "function-trace"), \ + C(DISPLAY_GRAPH, "display-graph"), -enum trace_iterator_flags { - TRACE_ITER_PRINT_PARENT = (1 << TRACE_ITER_PRINT_PARENT_BIT), - TRACE_ITER_SYM_OFFSET = (1 << TRACE_ITER_SYM_OFFSET_BIT), - TRACE_ITER_SYM_ADDR = (1 << TRACE_ITER_SYM_ADDR_BIT), - TRACE_ITER_VERBOSE = (1 << TRACE_ITER_VERBOSE_BIT), - TRACE_ITER_RAW = (1 << TRACE_ITER_RAW_BIT), - TRACE_ITER_HEX = (1 << TRACE_ITER_HEX_BIT), - TRACE_ITER_BIN = (1 << TRACE_ITER_BIN_BIT), - TRACE_ITER_BLOCK = (1 << TRACE_ITER_BLOCK_BIT), - TRACE_ITER_STACKTRACE = (1 << TRACE_ITER_STACKTRACE_BIT), - TRACE_ITER_PRINTK = (1 << TRACE_ITER_PRINTK_BIT), - TRACE_ITER_BRANCH = (1 << TRACE_ITER_BRANCH_BIT), - TRACE_ITER_ANNOTATE = (1 << TRACE_ITER_ANNOTATE_BIT), - TRACE_ITER_USERSTACKTRACE = (1 << TRACE_ITER_USERSTACKTRACE_BIT), - TRACE_ITER_SYM_USEROBJ = (1 << TRACE_ITER_SYM_USEROBJ_BIT), - TRACE_ITER_PRINTK_MSGONLY = (1 << TRACE_ITER_PRINTK_MSGONLY_BIT), - TRACE_ITER_CONTEXT_INFO = (1 << TRACE_ITER_CONTEXT_INFO_BIT), - TRACE_ITER_LATENCY_FMT = (1 << TRACE_ITER_LATENCY_FMT_BIT), - TRACE_ITER_SLEEP_TIME = (1 << TRACE_ITER_SLEEP_TIME_BIT), - TRACE_ITER_GRAPH_TIME = (1 << TRACE_ITER_GRAPH_TIME_BIT), - TRACE_ITER_RECORD_CMD = (1 << TRACE_ITER_RECORD_CMD_BIT), - TRACE_ITER_OVERWRITE = (1 << TRACE_ITER_OVERWRITE_BIT), - TRACE_ITER_STOP_ON_FREE = (1 << TRACE_ITER_STOP_ON_FREE_BIT), - TRACE_ITER_IRQ_INFO = (1 << TRACE_ITER_IRQ_INFO_BIT), - TRACE_ITER_MARKERS = (1 << TRACE_ITER_MARKERS_BIT), - TRACE_ITER_FUNCTION = (1 << TRACE_ITER_FUNCTION_BIT), - TRACE_ITER_DISPLAY_GRAPH = (1 << TRACE_ITER_DISPLAY_GRAPH_BIT), -}; +/* + * By defining C, we can make TRACE_FLAGS a list of bit names + * that will define the bits for the flag masks. + */ +#undef C +#define C(a, b) TRACE_ITER_##a##_BIT + +enum trace_iterator_bits { TRACE_FLAGS }; + +/* + * By redefining C, we can make TRACE_FLAGS a list of masks that + * use the bits as defined above. + */ +#undef C +#define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT) + +enum trace_iterator_flags { TRACE_FLAGS }; /* * TRACE_ITER_SYM_MASK masks the options in trace_flags that -- 2.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/