From 74d36eb759d7e60e9aed15430f4f5225707975c1 Mon Sep 17 00:00:00 2001
From: Vern Paxson <vern@corelight.com>
Date: Sat, 2 Mar 2024 14:21:22 -0800
Subject: [PATCH] script optimization support for clearing tables/vectors using
 "delete"

---
 src/script_opt/CPP/Stmts.cc   |  9 +++++++++
 src/script_opt/ProfileFunc.cc |  7 +++++--
 src/script_opt/Stmt.cc        |  6 +-----
 src/script_opt/ZAM/Expr.cc    |  2 +-
 src/script_opt/ZAM/Ops.in     | 11 +++++++++++
 src/script_opt/ZAM/Stmt.cc    | 10 ++++++++++
 6 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/src/script_opt/CPP/Stmts.cc b/src/script_opt/CPP/Stmts.cc
index ff80428849..40d9c0376f 100644
--- a/src/script_opt/CPP/Stmts.cc
+++ b/src/script_opt/CPP/Stmts.cc
@@ -159,6 +159,15 @@ void CPPCompile::GenAddStmt(const ExprStmt* es) {
 
 void CPPCompile::GenDeleteStmt(const ExprStmt* es) {
     auto op = es->StmtExpr();
+
+    if ( op->Tag() == EXPR_NAME ) {
+        if ( op->GetType()->Tag() == TYPE_TABLE )
+            Emit("%s->RemoveAll();", GenExpr(op, GEN_VAL_PTR));
+        else
+            Emit("%s->Resize(0);", GenExpr(op, GEN_VAL_PTR));
+        return;
+    }
+
     auto aggr = op->GetOp1();
     auto aggr_gen = GenExpr(aggr, GEN_VAL_PTR);
 
diff --git a/src/script_opt/ProfileFunc.cc b/src/script_opt/ProfileFunc.cc
index df83fe1dd8..901ca70429 100644
--- a/src/script_opt/ProfileFunc.cc
+++ b/src/script_opt/ProfileFunc.cc
@@ -161,8 +161,11 @@ TraversalCode ProfileFunc::PreStmt(const Stmt* s) {
         case STMT_DELETE: {
             auto ad_stmt = static_cast<const AddDelStmt*>(s);
             auto ad_e = ad_stmt->StmtExpr();
-            auto& lhs_t = ad_e->GetOp1()->GetType();
-            aggr_mods.insert(lhs_t.get());
+            auto lhs = ad_e->GetOp1();
+            if ( lhs )
+                aggr_mods.insert(lhs->GetType().get());
+            else
+                aggr_mods.insert(ad_e->GetType().get());
         } break;
 
         default: break;
diff --git a/src/script_opt/Stmt.cc b/src/script_opt/Stmt.cc
index 78605e78d0..9e8945037f 100644
--- a/src/script_opt/Stmt.cc
+++ b/src/script_opt/Stmt.cc
@@ -255,7 +255,7 @@ StmtPtr IfStmt::DoReduce(Reducer* c) {
         sl = make_intrusive<StmtList>(red_e_stmt, ThisPtr());
 
     if ( sl )
-        return TransformMe(sl, c);
+        return TransformMe(std::move(sl), c);
 
     return ThisPtr();
 }
@@ -418,14 +418,10 @@ StmtPtr AddDelStmt::DoReduce(Reducer* c) {
         return ThisPtr();
     }
 
-    if ( e->Tag() != EXPR_INDEX && e->Tag() != EXPR_FIELD )
-        Internal("bad \"add\"/\"delete\"");
-
     auto red_e_stmt = e->ReduceToSingletons(c);
 
     if ( red_e_stmt )
         return TransformMe(make_intrusive<StmtList>(red_e_stmt, ThisPtr()), c);
-
     else
         return ThisPtr();
 }
diff --git a/src/script_opt/ZAM/Expr.cc b/src/script_opt/ZAM/Expr.cc
index 7f81b10ee1..cf74cccc4c 100644
--- a/src/script_opt/ZAM/Expr.cc
+++ b/src/script_opt/ZAM/Expr.cc
@@ -874,7 +874,7 @@ const ZAMStmt ZAMCompiler::Call(const ExprStmt* e) {
 
     if ( IsZAM_BuiltIn(c.get()) ) {
         auto ret = LastInst();
-        insts1.back()->call_expr = c;
+        insts1.back()->call_expr = std::move(c);
         return ret;
     }
 
diff --git a/src/script_opt/ZAM/Ops.in b/src/script_opt/ZAM/Ops.in
index a4b2130d58..d8c60b7d65 100644
--- a/src/script_opt/ZAM/Ops.in
+++ b/src/script_opt/ZAM/Ops.in
@@ -2087,6 +2087,17 @@ type VC
 eval	EvalAddStmt(z.c.ToVal(z.t))
 
 
+op ClearTable
+op1-read
+type V
+eval	frame[z.v1].table_val->RemoveAll();
+
+op ClearVector
+op1-read
+type V
+eval	frame[z.v1].vector_val->Resize(0);
+
+
 op DelTable
 op1-read
 type VO
diff --git a/src/script_opt/ZAM/Stmt.cc b/src/script_opt/ZAM/Stmt.cc
index 9c802afb54..413fbcbc91 100644
--- a/src/script_opt/ZAM/Stmt.cc
+++ b/src/script_opt/ZAM/Stmt.cc
@@ -591,6 +591,16 @@ const ZAMStmt ZAMCompiler::CompileAdd(const AddStmt* as) {
 
 const ZAMStmt ZAMCompiler::CompileDel(const DelStmt* ds) {
     auto e = ds->StmtExprPtr();
+
+    if ( e->Tag() == EXPR_NAME ) {
+        auto n = e->AsNameExpr();
+
+        if ( n->GetType()->Tag() == TYPE_TABLE )
+            return ClearTableV(n);
+        else
+            return ClearVectorV(n);
+    }
+
     auto aggr = e->GetOp1()->AsNameExpr();
 
     if ( e->Tag() == EXPR_FIELD ) {