[CP] fix T_OP_STACK_OVERFLOW_CHECK reset child ptr leads core

src/sql/code_generator/ob_static_engine_expr_cg.cpp

@@ -1260,28 +1260,6 @@ int ObStaticEngineExprCG::alloc_so_check_exprs(const ObIArray<ObRawExpr *> &raw_
     if (OB_SUCC(ret) && stack_check_expr_cnt > 0) {
       LOG_TRACE("stack check expr needed",
                 K(exprs.count()), K(stack_check_expr_cnt), K(max_call_depth));
-      ObExpr *ori_base = exprs.get_data();
-      OZ(exprs.reserve(exprs.count() + stack_check_expr_cnt));
-      ObExpr *base = exprs.get_data();
-      // relocate expr ptr
-      if (OB_SUCC(ret) && ori_base != base) {
-        const int64_t offset = reinterpret_cast<char *>(base) - reinterpret_cast<char *>(ori_base);
-        FOREACH_CNT(e, raw_exprs) {
-          (*e)->set_rt_expr(reinterpret_cast<ObExpr *>(
-                  reinterpret_cast<char *>(get_rt_expr(**e)) + offset));
-        }
-        FOREACH_CNT(e, exprs_call_depth) {
-          *reinterpret_cast<char **>(&e->expr_) += offset;
-        }
-        FOREACH_CNT(e, exprs) {
-          for (int64_t i = 0; i < e->parent_cnt_; i++) {
-            *reinterpret_cast<char **>(&e->parents_[i]) += offset;
-          }
-          for (int64_t i = 0; i < e->arg_cnt_; i++) {
-            *reinterpret_cast<char **>(&e->args_[i]) += offset;
-          }
-        }
-      }
 
       FOREACH_CNT_X(ecd, exprs_call_depth, OB_SUCC(ret)) {
         if (ecd->need_stack_check_) {
@@ -1295,7 +1273,7 @@ int ObStaticEngineExprCG::alloc_so_check_exprs(const ObIArray<ObRawExpr *> &raw_
             }
           }
           if (OB_SUCC(ret) && e->parent_cnt_ > 0) {
-            OZ(add_so_check_expr_above(exprs, e));
+            e->need_stack_check_ = true;
           }
         }
       } // END FOREACH_CNT_X
@@ -1304,52 +1282,6 @@ int ObStaticEngineExprCG::alloc_so_check_exprs(const ObIArray<ObRawExpr *> &raw_
   return ret;
 }
 
-int ObStaticEngineExprCG::add_so_check_expr_above(ObIArray<ObExpr> &exprs, ObExpr *e)
-{
-  int ret = OB_SUCCESS;
-  ObExpr *base = exprs.get_data();
-  CK(NULL != e);
-  CK(e->parent_cnt_ > 0 && e->arg_cnt_ > 0);
-  OZ(exprs.push_back(*e));
-  CK(base == exprs.get_data());
-  if (OB_SUCC(ret)) {
-    // stack overflow check expr point to the same ObDatum of child.
-    ObExpr *so = &exprs.at(exprs.count() - 1);
-    so->type_ = T_OP_STACK_OVERFLOW_CHECK;
-    so->extra_ = 0;
-    so->inner_functions_ = 0;
-    so->inner_func_cnt_ = 0;
-    ObExpr **parents = static_cast<ObExpr **>(allocator_.alloc(sizeof(ObExpr *) * 2));
-    if (NULL == parents) {
-      ret = OB_ALLOCATE_MEMORY_FAILED;
-      LOG_WARN("allocate memory failed", K(ret));
-    } else {
-      ObExpr **args = parents + 1;
-
-      parents[0] = so;
-      args[0] = e;
-
-      e->parents_ = parents;
-      e->parent_cnt_ = 1;
-      so->args_ = args;
-      so->arg_cnt_ = 1;
-
-      for (int64_t i = 0; i < so->parent_cnt_; i++) {
-        ObExpr *p = so->parents_[i];
-        for (int64_t j = 0; j < p->arg_cnt_; j++) {
-          if (p->args_[j] == e) {
-            p->args_[j] = so;
-          }
-        }
-      }
-
-      so->eval_func_ = ObExprUtil::eval_stack_overflow_check;
-      so->eval_batch_func_ = ObExprUtil::eval_batch_stack_overflow_check;
-    }
-  }
-  return ret;
-}
-
 int ObStaticEngineExprCG::calc_exprs_res_buf_len(const ObIArray<ObRawExpr *> &raw_exprs)
 {
   int ret = OB_SUCCESS;

src/sql/code_generator/ob_static_engine_expr_cg.h

@@ -196,9 +196,6 @@ private:
   // alloc stack overflow check exprs.
   int alloc_so_check_exprs(const common::ObIArray<ObRawExpr *> &raw_exprs,
                            ObExprFrameInfo &expr_info);
-  // add stack overflow check expr above %e
-  int add_so_check_expr_above(common::ObIArray<ObExpr> &exprs,
-                              ObExpr *e);
 
   // calculate res_buf_len_ for exprs' datums
   int calc_exprs_res_buf_len(const common::ObIArray<ObRawExpr *> &raw_exprs);

src/sql/engine/expr/ob_expr.cpp

@@ -609,16 +609,20 @@ int ObExpr::eval_one_datum_of_batch(ObEvalCtx &ctx, common::ObDatum *&datum) con
   }
   datum = reinterpret_cast<ObDatum *>(frame + datum_off_) + ctx.get_batch_idx();
   if (need_evaluate) {
-    reset_datum_ptr(frame, ctx.get_batch_size(), ctx.get_batch_idx());
-    ret = eval_func_(*this, ctx, *datum);
-    if (OB_SUCC(ret)) {
-      ObBitVector *evaluated_flags = to_bit_vector(frame + eval_flags_off_);
-      evaluated_flags->set(ctx.get_batch_idx());
+    if (OB_UNLIKELY(need_stack_check_) && OB_FAIL(check_stack_overflow())) {
+      SQL_LOG(WARN, "failed to check stack overflow", K(ret));
     } else {
-      datum->set_null();
-    }
-    if (datum->is_null()) {
-      info->notnull_ = false;
+      reset_datum_ptr(frame, ctx.get_batch_size(), ctx.get_batch_idx());
+      ret = eval_func_(*this, ctx, *datum);
+      if (OB_SUCC(ret)) {
+        ObBitVector *evaluated_flags = to_bit_vector(frame + eval_flags_off_);
+        evaluated_flags->set(ctx.get_batch_idx());
+      } else {
+        datum->set_null();
+      }
+      if (datum->is_null()) {
+        info->notnull_ = false;
+      }
     }
   }
 
@@ -655,17 +659,21 @@ int ObExpr::do_eval_batch(ObEvalCtx &ctx,
       info->notnull_ = false;
       info->point_to_frame_ = true;
     }
-    ret = (*eval_batch_func_)(*this, ctx, skip, size);
-    if (OB_SUCC(ret)) {
-      if (!info->evaluated_) {
-        info->cnt_ = size;
-        info->evaluated_ = true;
-      }
+    if (OB_UNLIKELY(need_stack_check_) && OB_FAIL(check_stack_overflow())) {
+      SQL_LOG(WARN, "failed to check stack overflow", K(ret));
     } else {
-      ObDatum *datum = reinterpret_cast<ObDatum *>(frame + datum_off_);
-      ObDatum *datum_end = datum + size;
-      for (; datum < datum_end; datum += 1) {
-        datum->set_null();
+      ret = (*eval_batch_func_)(*this, ctx, skip, size);
+      if (OB_SUCC(ret)) {
+        if (!info->evaluated_) {
+          info->cnt_ = size;
+          info->evaluated_ = true;
+        }
+      } else {
+        ObDatum *datum = reinterpret_cast<ObDatum *>(frame + datum_off_);
+        ObDatum *datum_end = datum + size;
+        for (; datum < datum_end; datum += 1) {
+          datum->set_null();
+        }
       }
     }
   }

src/sql/engine/expr/ob_expr.h

@@ -20,6 +20,7 @@
 #include "sql/engine/ob_serializable_function.h"
 #include "objit/common/ob_item_type.h"
 #include "sql/engine/ob_bit_vector.h"
+#include "common/ob_common_utility.h"
 
 namespace oceanbase
 {
@@ -610,6 +611,7 @@ public:
       uint64_t is_static_const_:1; // is const during the whole execution
       uint64_t is_boolean_:1; // to distinguish result of this expr between and int tc
       uint64_t is_dynamic_const_:1; // is const during the subplan execution, including exec param
+      uint64_t need_stack_check_:1; // the expression tree depth needs to check whether the stack overflows
     };
     uint64_t flag_;
   };
@@ -976,7 +978,6 @@ OB_INLINE int ObExpr::eval(ObEvalCtx &ctx, common::ObDatum *&datum) const
   OB_ASSERT(NULL != frame);
 	datum = (ObDatum *)(frame + datum_off_);
   ObEvalInfo *eval_info = (ObEvalInfo *)(frame + eval_info_off_);
-
   if (is_batch_result()) {
     if (NULL == eval_func_ || eval_info->projected_) {
       datum = datum + ctx.get_batch_idx();
@@ -985,14 +986,18 @@ OB_INLINE int ObExpr::eval(ObEvalCtx &ctx, common::ObDatum *&datum) const
     }
   } else if (NULL != eval_func_ && !eval_info->evaluated_) {
 	// do nothing for const/column reference expr or already evaluated expr
-		if (datum->ptr_ != frame + res_buf_off_) {
-			datum->ptr_ = frame + res_buf_off_;
-		}
-		ret = eval_func_(*this, ctx, *datum);
-    if (OB_LIKELY(common::OB_SUCCESS == ret)) {
-      eval_info->evaluated_ = true;
+    if (OB_UNLIKELY(need_stack_check_) && OB_FAIL(check_stack_overflow())) {
+      SQL_LOG(WARN, "failed to check stack overflow", K(ret));
     } else {
-      datum->set_null();
+      if (datum->ptr_ != frame + res_buf_off_) {
+        datum->ptr_ = frame + res_buf_off_;
+      }
+      ret = eval_func_(*this, ctx, *datum);
+      if (OB_LIKELY(common::OB_SUCCESS == ret)) {
+        eval_info->evaluated_ = true;
+      } else {
+        datum->set_null();
+      }
     }
 	}
 	return ret;