From a4cddfbacd50d71ef104b6606755db9755307777 Mon Sep 17 00:00:00 2001
From: Tim Wojtulewicz <tim@corelight.com>
Date: Tue, 7 Oct 2025 21:44:40 -0700
Subject: [PATCH] Add versions of IfStmt and StmtList for use in debugger

---
 src/Stmt.cc | 57 +++++++++++++++++++++++++++++++++++++++--------------
 src/Stmt.h  | 19 +++++++++++++++++-
 src/parse.y | 21 +++++++++++++++++---
 3 files changed, 78 insertions(+), 19 deletions(-)

diff --git a/src/Stmt.cc b/src/Stmt.cc
index 9efda21df1..4585190066 100644
--- a/src/Stmt.cc
+++ b/src/Stmt.cc
@@ -436,15 +436,7 @@ ValPtr IfStmt::DoExec(Frame* f, Val* v, StmtFlowType& flow) {
 
     f->SetNextStmt(do_stmt);
 
-    if ( ! pre_execute_stmt(do_stmt, f) ) { // ### Abort or something
-    }
-
-    auto result = do_stmt->Exec(f, flow);
-
-    if ( ! post_execute_stmt(do_stmt, f, result.get(), &flow) ) { // ### Abort or something
-    }
-
-    return result;
+    return do_stmt->Exec(f, flow);
 }
 
 bool IfStmt::IsPure() const { return e->IsPure() && s1->IsPure() && s2->IsPure(); }
@@ -488,6 +480,23 @@ TraversalCode IfStmt::Traverse(TraversalCallback* cb) const {
     HANDLE_TC_STMT_POST(tc);
 }
 
+ValPtr DebugIfStmt::DoExec(Frame* f, Val* v, StmtFlowType& flow) {
+    // Treat 0 as false, but don't require 1 for true.
+    Stmt* do_stmt = v->IsZero() ? s2.get() : s1.get();
+
+    f->SetNextStmt(do_stmt);
+
+    if ( ! pre_execute_stmt(do_stmt, f) ) { // ### Abort or something
+    }
+
+    auto result = do_stmt->Exec(f, flow);
+
+    if ( ! post_execute_stmt(do_stmt, f, result.get(), &flow) ) { // ### Abort or something
+    }
+
+    return result;
+}
+
 static StmtTag get_last_stmt_tag(const Stmt* stmt) {
     if ( ! stmt )
         return STMT_NULL;
@@ -1409,14 +1418,8 @@ ValPtr StmtList::Exec(Frame* f, StmtFlowType& flow) {
 
         f->SetNextStmt(stmt);
 
-        if ( ! pre_execute_stmt(stmt, f) ) { // ### Abort or something
-        }
-
         auto result = stmt->Exec(f, flow);
 
-        if ( ! post_execute_stmt(stmt, f, result.get(), &flow) ) { // ### Abort or something
-        }
-
         if ( flow != FLOW_NEXT || result || f->HasDelayed() )
             return result;
     }
@@ -1469,6 +1472,30 @@ TraversalCode StmtList::Traverse(TraversalCallback* cb) const {
     HANDLE_TC_STMT_POST(tc);
 }
 
+ValPtr DebugStmtList::Exec(Frame* f, StmtFlowType& flow) {
+    RegisterAccess();
+    flow = FLOW_NEXT;
+
+    for ( const auto& stmt_ptr : stmts ) {
+        auto stmt = stmt_ptr.get();
+
+        f->SetNextStmt(stmt);
+
+        if ( ! pre_execute_stmt(stmt, f) ) { // ### Abort or something
+        }
+
+        auto result = stmt->Exec(f, flow);
+
+        if ( ! post_execute_stmt(stmt, f, result.get(), &flow) ) { // ### Abort or something
+        }
+
+        if ( flow != FLOW_NEXT || result || f->HasDelayed() )
+            return result;
+    }
+
+    return nullptr;
+}
+
 InitStmt::InitStmt(std::vector<IDPtr> arg_inits) : Stmt(STMT_INIT) {
     inits = std::move(arg_inits);
 
diff --git a/src/Stmt.h b/src/Stmt.h
index 1e16803328..16b3488e75 100644
--- a/src/Stmt.h
+++ b/src/Stmt.h
@@ -102,7 +102,7 @@ protected:
     ExprPtr e;
 };
 
-class IfStmt final : public ExprStmt {
+class IfStmt : public ExprStmt {
 public:
     IfStmt(ExprPtr test, StmtPtr s1, StmtPtr s2);
     ~IfStmt() override;
@@ -135,6 +135,15 @@ protected:
     StmtPtr s2;
 };
 
+class DebugIfStmt final : public IfStmt {
+public:
+    DebugIfStmt(ExprPtr test, StmtPtr s1, StmtPtr s2) : IfStmt(test, s1, s2) {}
+    ~DebugIfStmt() override = default;
+
+protected:
+    ValPtr DoExec(Frame* f, Val* v, StmtFlowType& flow) override;
+};
+
 class Case final : public Obj {
 public:
     Case(ListExprPtr c, IDPList* types, StmtPtr arg_s);
@@ -452,6 +461,14 @@ protected:
     void ResetStmts(std::vector<StmtPtr> new_stmts) { stmts = std::move(new_stmts); }
 };
 
+class DebugStmtList : public StmtList {
+public:
+    DebugStmtList() = default;
+    ~DebugStmtList() override = default;
+
+    ValPtr Exec(Frame* f, StmtFlowType& flow) override;
+};
+
 class InitStmt final : public Stmt {
 public:
     explicit InitStmt(std::vector<IDPtr> arg_inits);
diff --git a/src/parse.y b/src/parse.y
index be4ad5c1d4..e2afae078c 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -163,6 +163,10 @@ static int func_hdr_cond_epoch = 0;
 EnumType* cur_enum_type = nullptr;
 static ID* cur_decl_type_id = nullptr;
 
+namespace zeek::detail {
+extern bool g_policy_debug;
+}
+
 static void parse_new_enum(void) {
     // Starting a new enum definition.
     assert(cur_enum_type == nullptr);
@@ -1843,7 +1847,10 @@ stmt:
 			{
 			reject_directive($5);
 			set_location(@1, @4);
-			$$ = new IfStmt({AdoptRef{}, $3}, {AdoptRef{}, $5}, make_intrusive<NullStmt>());
+			if ( g_policy_debug )
+				$$ = new DebugIfStmt({AdoptRef{}, $3}, {AdoptRef{}, $5}, make_intrusive<NullStmt>());
+			else
+				$$ = new IfStmt({AdoptRef{}, $3}, {AdoptRef{}, $5}, make_intrusive<NullStmt>());
 			script_coverage_mgr.AddStmt($$);
 			}
 
@@ -1852,7 +1859,10 @@ stmt:
 			reject_directive($5);
 			reject_directive($7);
 			set_location(@1, @4);
-			$$ = new IfStmt({AdoptRef{}, $3}, {AdoptRef{}, $5}, {AdoptRef{}, $7});
+			if ( g_policy_debug )
+				$$ = new DebugIfStmt({AdoptRef{}, $3}, {AdoptRef{}, $5}, {AdoptRef{}, $7});
+			else
+				$$ = new IfStmt({AdoptRef{}, $3}, {AdoptRef{}, $5}, {AdoptRef{}, $7});
 			script_coverage_mgr.AddStmt($$);
 			}
 
@@ -1976,7 +1986,12 @@ stmt_list:
 			$1->UpdateLocationEndInfo(@2);
 			}
 	|
-			{ $$ = new StmtList(); }
+			{
+			if ( g_policy_debug )
+				$$ = new DebugStmtList();
+			else
+				$$ = new StmtList();
+			}
 	;
 
 event: