Add basic support of Cgroup Array

src/cc/export/helpers.h

@@ -103,6 +103,17 @@ struct _name##_table_t { \
 __attribute__((section("maps/perf_array"))) \
 struct _name##_table_t _name = { .max_entries = (_max_entries) }
 
+// Table for cgroup file descriptors
+#define BPF_CGROUP_ARRAY(_name, _max_entries) \
+struct _name##_table_t { \
+  int key; \
+  u32 leaf; \
+  int (*check_current_task) (int); \
+  u32 max_entries; \
+}; \
+__attribute__((section("maps/cgroup_array"))) \
+struct _name##_table_t _name = { .max_entries = (_max_entries) }
+
 #define BPF_HASH1(_name) \
   BPF_TABLE("hash", u64, u64, _name, 10240)
 #define BPF_HASH2(_name, _key_type) \

src/cc/frontends/clang/b_frontend_action.cc

@@ -459,6 +459,9 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
           } else if (memb_name == "perf_counter_value") {
             prefix = "bpf_perf_event_read_value";
             suffix = ")";
+          } else if (memb_name == "check_current_task") {
+            prefix = "bpf_current_task_under_cgroup";
+            suffix = ")";
           } else {
             error(Call->getLocStart(), "invalid bpf_table operation %0") << memb_name;
             return false;
@@ -762,6 +765,8 @@ bool BTypeVisitor::VisitVarDecl(VarDecl *Decl) {
       table.max_entries = numcpu;
     } else if (A->getName() == "maps/perf_array") {
       map_type = BPF_MAP_TYPE_PERF_EVENT_ARRAY;
+    } else if (A->getName() == "maps/cgroup_array") {
+      map_type = BPF_MAP_TYPE_CGROUP_ARRAY;
     } else if (A->getName() == "maps/stacktrace") {
       map_type = BPF_MAP_TYPE_STACK_TRACE;
     } else if (A->getName() == "maps/extern") {