From 1c80c9098052ff7a07bb43df084c0f9d2b2e278c 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 | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/include/lttng/ust-tracepoint-event.h b/include/lttng/ust-tracepoint-event.h index 645c566b..d9801a8f 100644 --- a/include/lttng/ust-tracepoint-event.h +++ b/include/lttng/ust-tracepoint-event.h @@ -169,6 +169,7 @@ static const char \ #define TRACEPOINT_ENUM(_provider, _name, _values) \ const struct lttng_enum_entry __enum_values__##_provider##_##_name[] = { \ _values \ + ctf_enum_value("", 0) /* Dummy, 0-len array forbidden by C99. */ \ }; #include TRACEPOINT_INCLUDE @@ -290,6 +291,7 @@ 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. */ \ }; #undef TRACEPOINT_ENUM @@ -297,7 +299,7 @@ static const char \ static const struct lttng_enum_desc __enum_##_provider##_##_name = { \ .name = #_provider "_" #_name, \ .entries = __enum_values__##_provider##_##_name, \ - .nr_entries = _TP_ARRAY_SIZE(__enum_values__##_provider##_##_name), \ + .nr_entries = _TP_ARRAY_SIZE(__enum_values__##_provider##_##_name) - 1, \ }; #include TRACEPOINT_INCLUDE @@ -735,8 +737,8 @@ 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; \ \ @@ -869,7 +871,7 @@ static 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 = { \ @@ -896,6 +898,7 @@ static 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. */ }; @@ -909,7 +912,7 @@ 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