From 3312e19d5b0d73194d41ebbe7981c9e7ab588daa Mon Sep 17 00:00:00 2001
From: AmazingPP <1620535041@qq.com>
Date: Mon, 18 Jul 2022 20:31:21 +0800
Subject: [PATCH 1/2] Fix local const variables can be modified via loops

---
 src/parse.y | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/parse.y b/src/parse.y
index 252b7390e2..fcea106758 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -1911,6 +1911,9 @@ for_head:
 				{
 				if ( loop_var->IsGlobal() )
 					loop_var->Error("global variable used in for loop");
+
+				if ( loop_var->IsConst() )
+					loop_var->Error("constant used in for loop");
 				}
 
 			else
@@ -1945,6 +1948,9 @@ for_head:
 				{
 				if ( key_var->IsGlobal() )
 					key_var->Error("global variable used in for loop");
+
+				if ( key_var->IsConst() )
+					key_var->Error("constant used in for loop");
 				}
 			else
 				key_var = install_ID($3, module, false, false);
@@ -1953,6 +1959,9 @@ for_head:
 				{
 				if ( val_var->IsGlobal() )
 					val_var->Error("global variable used in for loop");
+
+				if ( val_var->IsConst() )
+					val_var->Error("constant used in for loop");
 				}
 			else
 				val_var = install_ID($5, module, false, false);
@@ -1975,6 +1984,9 @@ for_head:
 				{
 				if ( val_var->IsGlobal() )
 					val_var->Error("global variable used in for loop");
+
+				if ( val_var->IsConst() )
+					val_var->Error("constant used in for loop");
 				}
 			else
 				val_var = install_ID($7, module, false, false);
@@ -2004,6 +2016,9 @@ local_id:
 				{
 				if ( $$->IsGlobal() )
 					$$->Error("already a global identifier");
+				
+				if ( $$->IsConst() )
+					$$->Error("already a const identifier");
 				delete [] $1;
 				}
 

From f5f489ba106994bae3d2c310a2d0856a625e92c7 Mon Sep 17 00:00:00 2001
From: AmazingPP <1620535041@qq.com>
Date: Tue, 19 Jul 2022 09:08:42 +0800
Subject: [PATCH 2/2] Add help function to check loop variable

---
 src/parse.y | 48 ++++++++++++++----------------------------------
 1 file changed, 14 insertions(+), 34 deletions(-)

diff --git a/src/parse.y b/src/parse.y
index fcea106758..7e8828b418 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -247,6 +247,15 @@ static bool expr_is_table_type_name(const Expr* expr)
 	return false;
 	}
 
+static void check_loop_var(ID* var)
+	{
+	if ( var->IsGlobal() )
+ 		var->Error("global variable used in for loop");
+
+ 	if ( var->IsConst() )
+ 		var->Error("constant used in for loop");
+	}
+
 static void build_global(ID* id, Type* t, InitClass ic, Expr* e,
                          std::vector<AttrPtr>* attrs, DeclType dt)
 	{
@@ -1908,14 +1917,7 @@ for_head:
 			auto loop_var = lookup_ID($3, current_module.c_str());
 
 			if ( loop_var )
-				{
-				if ( loop_var->IsGlobal() )
-					loop_var->Error("global variable used in for loop");
-
-				if ( loop_var->IsConst() )
-					loop_var->Error("constant used in for loop");
-				}
-
+				check_loop_var(loop_var.get());
 			else
 				{
 				loop_var = install_ID($3, current_module.c_str(),
@@ -1945,24 +1947,12 @@ for_head:
 
 			// Validate previous definitions as needed.
 			if ( key_var )
-				{
-				if ( key_var->IsGlobal() )
-					key_var->Error("global variable used in for loop");
-
-				if ( key_var->IsConst() )
-					key_var->Error("constant used in for loop");
-				}
+				check_loop_var(key_var.get());
 			else
 				key_var = install_ID($3, module, false, false);
 
 			if ( val_var )
-				{
-				if ( val_var->IsGlobal() )
-					val_var->Error("global variable used in for loop");
-
-				if ( val_var->IsConst() )
-					val_var->Error("constant used in for loop");
-				}
+				check_loop_var(val_var.get());
 			else
 				val_var = install_ID($5, module, false, false);
 
@@ -1981,13 +1971,7 @@ for_head:
 			auto val_var = lookup_ID($7, module);
 
 			if ( val_var )
-				{
-				if ( val_var->IsGlobal() )
-					val_var->Error("global variable used in for loop");
-
-				if ( val_var->IsConst() )
-					val_var->Error("constant used in for loop");
-				}
+				check_loop_var(val_var.get());
 			else
 				val_var = install_ID($7, module, false, false);
 
@@ -2014,11 +1998,7 @@ local_id:
 
 			if ( $$ )
 				{
-				if ( $$->IsGlobal() )
-					$$->Error("already a global identifier");
-				
-				if ( $$->IsConst() )
-					$$->Error("already a const identifier");
+				check_loop_var($$);
 				delete [] $1;
 				}