From 0febf0188de9401f656cc5963cd5893b2f0169a4 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 30 May 2016 18:47:50 +0200 Subject: [PATCH] Fix: don't generate 0-len array in tracepoint probes It is forbidden by C99, and gcc/g++ in pedantic mode generates errors for e.g. field-less events. Signed-off-by: Mathieu Desnoyers --- include/lttng/ust-tracepoint-event.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/include/lttng/ust-tracepoint-event.h b/include/lttng/ust-tracepoint-event.h index 48085670..1e75d613 100644 --- a/include/lttng/ust-tracepoint-event.h +++ b/include/lttng/ust-tracepoint-event.h @@ -208,6 +208,7 @@ static const char \ #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields) \ static const struct lttng_event_field __event_fields___##_provider##___##_name[] = { \ _fields \ + ctf_integer(int, dummy, 0) /* Dummy, C99 forbids 0-len array. */ \ }; #include TRACEPOINT_INCLUDE @@ -618,8 +619,8 @@ void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args)) \ size_t __event_len, __event_align; \ size_t __dynamic_len_idx = 0; \ union { \ - size_t __dynamic_len[_TP_ARRAY_SIZE(__event_fields___##_provider##___##_name)]; \ - char __filter_stack_data[2 * sizeof(unsigned long) * _TP_ARRAY_SIZE(__event_fields___##_provider##___##_name)]; \ + size_t __dynamic_len[_TP_ARRAY_SIZE(__event_fields___##_provider##___##_name) - 1]; \ + char __filter_stack_data[2 * sizeof(unsigned long) * (_TP_ARRAY_SIZE(__event_fields___##_provider##___##_name) - 1)]; \ } __stackvar; \ int __ret; \ \ @@ -748,7 +749,7 @@ const struct lttng_event_desc __event_desc___##_provider##_##_name = { \ .probe_callback = (void (*)(void)) &__event_probe__##_provider##___##_template,\ .ctx = NULL, \ .fields = __event_fields___##_provider##___##_template, \ - .nr_fields = _TP_ARRAY_SIZE(__event_fields___##_provider##___##_template), \ + .nr_fields = _TP_ARRAY_SIZE(__event_fields___##_provider##___##_template) - 1, \ .loglevel = &__ref_loglevel___##_provider##___##_name, \ .signature = __tp_event_signature___##_provider##___##_template, \ .u = { .ext = { .model_emf_uri = &__ref_model_emf_uri___##_provider##___##_name } }, \ @@ -771,6 +772,7 @@ const struct lttng_event_desc __event_desc___##_provider##_##_name = { \ static const struct lttng_event_desc *_TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER)[] = { #include TRACEPOINT_INCLUDE + NULL, /* Dummy, C99 forbids 0-len array. */ }; @@ -784,7 +786,7 @@ static const struct lttng_event_desc *_TP_COMBINE_TOKENS(__event_desc___, TRACEP static struct lttng_probe_desc _TP_COMBINE_TOKENS(__probe_desc___, TRACEPOINT_PROVIDER) = { .provider = __tp_stringify(TRACEPOINT_PROVIDER), .event_desc = _TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER), - .nr_events = _TP_ARRAY_SIZE(_TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER)), + .nr_events = _TP_ARRAY_SIZE(_TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER)) - 1, .head = { NULL, NULL }, .lazy_init_head = { NULL, NULL }, .lazy = 0, -- 2.34.1