Fixed issue #42

Author: nspyrop03

compiler/ast.hpp

@@ -3028,6 +3028,14 @@ class VarDef : public AST
     {
         for (char *id : ids)
         {
+            std::string varName(id);
+            if (st.getCurrentScope().isThereNameInLocals(varName)) 
+            {
+                std::ostringstream oss;
+                oss << "Duplicate variable definition: variable \"" << varName << "\" is already defined in the current scope.";
+                semantic_error(line, column, oss.str());
+            }
+            
             STEntry *entry = new STEntry();
             if (!type->getParenthesisList().empty())
             {

compiler/symbol.hpp

@@ -165,6 +165,10 @@ class Scope {
             return locals;
         }
 
+        bool isThereNameInLocals(const std::string& name) const {
+            return locals.find(name) != locals.end();
+        }
+
         STEntry* searchPreviousDeclaration(const std::string& name) const {
             if(locals.find(name) == locals.end())
                 return nullptr;

llvm/ast.hpp

@@ -2983,6 +2983,14 @@ class VarDef : public AST
     {
         for (char *id : ids)
         {
+            std::string varName(id);
+            if (st.getCurrentScope().isThereNameInLocals(varName)) 
+            {
+                std::ostringstream oss;
+                oss << "Duplicate variable definition: variable \"" << varName << "\" is already defined in the current scope.";
+                semantic_error(line, column, oss.str());
+            }
+            
             STEntry *entry = new STEntry();
             if (!type->getParenthesisList().empty())
             {

llvm/symbol.hpp

@@ -131,6 +131,10 @@ class Scope {
             locals[name] = entry;
         }
 
+        bool isThereNameInLocals(const std::string& name) const {
+            return locals.find(name) != locals.end();
+        }
+
         STEntry* lookup(const std::string& name) {
             if (locals.find(name) == locals.end()) {
                 return nullptr;

semantic/ast.hpp

@@ -1684,6 +1684,14 @@ class VarDef : public AST
     {
         for (char *id : ids)
         {
+            std::string varName(id);
+            if (st.getCurrentScope().isThereNameInLocals(varName)) 
+            {
+                std::ostringstream oss;
+                oss << "Duplicate variable definition: variable \"" << varName << "\" is already defined in the current scope.";
+                semantic_error(line, column, oss.str());
+            }
+            
             STEntry *entry = new STEntry();
             if (!type->getParenthesisList().empty())
             {

semantic/symbol.hpp

@@ -131,6 +131,10 @@ class Scope {
             locals[name] = entry;
         }
 
+        bool isThereNameInLocals(const std::string& name) const {
+            return locals.find(name) != locals.end();
+        }
+
         STEntry* lookup(const std::string& name) {
             if (locals.find(name) == locals.end()) {
                 return nullptr;

testing/issues/dup_var.dana

@@ -0,0 +1,7 @@
+def main
+   var a b a is int
+begin
+   a := 1
+   writeInteger: a
+   writeString: "\nthis program is wrong!!!\n"
+end