Compile error when outputting to const vars in for() loops

OpenDreamProject · Dec 7, 2024 · 85efc53 · 85efc53
1 parent e638422
commit 85efc53
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diff --git a/... Tests/Statements/For/reuse_decl_const.dm → .../Tests/Statements/For/reuse_decl_const.dm b/... Tests/Statements/For/reuse_decl_const.dm → .../Tests/Statements/For/reuse_decl_const.dm
@@ -1,4 +1,4 @@
-// COMPILE ERROR
+// COMPILE ERROR OD0501
 
 /datum
 	var/const/idx = 0

diff --git a/DMCompiler/DM/Builders/DMProcBuilder.cs b/DMCompiler/DM/Builders/DMProcBuilder.cs
@@ -487,6 +487,11 @@ public void ProcessStatementFor(DMASTProcStatementFor statementFor) {
                                 outputExpr = exprRange.Value;
                             }
 
+                            if (outputExpr is DMASTIdentifier identifier &&
+                                dmObject.GetVariable(identifier.Identifier) is { IsConst: true }) {
+                                compiler.Emit(WarningCode.WriteToConstant, outputExpr.Location, "Cannot change constant value");
+                            }
+
                             var outputVar = _exprBuilder.Create(outputExpr);
 
                             var start = _exprBuilder.Create(exprRange.StartRange);