symbol table for generating unique variable names during code generation

tools/lcd/idl/include/symbol_table.h

+#ifndef SYMBOL_TABLE_H
+#define SYMBOL_TABLE_H
+
+#include <vector>
+#include <string>
+
+class SymbolTable 
+{
+  unsigned int last_tmp_;
+  vector<const char*> symbols_;
+ public:
+  SymbolTable();
+  const char* unique_tmp();
+  bool contains();
+  void insert(const char *symbol);
+  void insert(std::vector<const char*> symbols);
+};
+
+#endif

tools/lcd/idl/symbol_table.cpp

+#include "symbol_table.h"
+
+SymbolTable::SymbolTable()
+{
+  // init symbols
+}
+
+SymbolTable::SymbolTable(std::vector<const char*> symbols)
+{
+  this->symbols_ = symbols;
+}
+
+/*
+ * returns a unique const char* that begins with tmp 
+ * that is not already in symbol table
+ * adds to symbol table
+ */
+const char* SymbolTable::unique_tmp()
+{
+  std::string str_tmp = "tmp" + std::to_string(this->last_tmp_ + 1);
+  char *tmp = (char*) malloc(sizof(char)*(str_tmp.length()+1));
+  std::strcpy(tmp, str_tmp.c_str());
+  if(!contains(tmp)) {
+    this->last_tmp_ += 1;
+    this->insert(tmp);
+    return tmp;
+  } else {
+    this->last_tmp_ += 1;
+    return unique_tmp();
+  }
+}
+
+/*
+ * returns true if symbol table contains symbol
+ */
+bool SymbolTable::contains(const char *symbol)
+{
+  for(std::vector<const char*>::iterator it = this->symbols_.begin(); it != this->symbols_.end(); it ++) {
+    const char *str = (const char*) *it;
+    if( strcmp(str, symbol) == 0) {
+      return true;
+    }
+  }
+  return false;
+}
+
+/*
+ * inserts symbol into symbol table
+ * if symbol is already in table returns -1
+ * returns 0 on success
+ */
+int SymbolTable::insert(const char *symbol)
+{
+  if(contains(symbol))
+    return -1;
+  
+  this->symbols_.push_back(symbol);
+  return 0;
+}
+
+/*
+ * inserts a list of symbols into the symbol table
+ * if any of these symbols are already in the table it fails
+ * and returns -1
+ * returns 0 on success
+ */
+int SymbolTable::insert(std::vector<const char*> symbols)
+{
+  for(std::vector<const char*>::iterator it = symbols.begin(); it != symbols.end(); it ++) {
+    const char *str = (const char*) *it;
+    if(contains(str))
+      return -1;
+  }
+  
+  this->symbols_.insert(this->symbols_.end(), symbols.begin(), symbols.end());
+  return 0;
+}