From 5b307fe7379cb1e47d4df1f735b8c8a5fc5263f3 Mon Sep 17 00:00:00 2001
From: Austin Sun <austinsunc@yahoo.com>
Date: Mon, 16 May 2016 17:34:15 -0700
Subject: [PATCH] ummm not sure

---
 ast.cc | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 ast.h  | 19 ++++++++++++++++++-
 2 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/ast.cc b/ast.cc
index 146c42f..d93cd01 100644
--- a/ast.cc
+++ b/ast.cc
@@ -9,6 +9,7 @@
 #include <string.h> // strdup
 #include <stdio.h>  // printf
 
+
 Node::Node(yyltype loc) {
     location = new yyltype(loc);
     parent = NULL;
@@ -46,3 +47,51 @@ Identifier::Identifier(yyltype loc, const char *n) : Node(loc) {
 void Identifier::PrintChildren(int indentLevel) {
     printf("%s", name);
 }
+
+/*------------------------------------------------------------------------------------
+ * Symbol Table Information
+ *----------------------------------------------------------------------------------*/
+SymbolTable symbols;
+
+pair<Decl*,llvm::Value *> findSymbol(string s) {
+    for(int i = symbols.size() - 1; i >= 0; i--) {
+        if(symbols[i].count(s) > 0) return symbols[i][s];
+    }
+    return make_pair<Decl*,llvm::Value *>(NULL,NULL);
+}
+
+pair<Decl*,llvm::Value *> findSymbol(Decl* d) {
+    string s(d->GetIdentifier()->GetName());
+    return findSymbol(s);
+}
+
+bool isInCurrentScope(string s) {
+    if(symbols.size() == 0) return false;
+    return symbols[symbols.size()-1].count(s);
+}
+
+bool isInCurrentScope(Decl* d) {
+    string s(d->GetIdentifier()->GetName());
+    return isInCurrentScope(s);
+}
+
+bool isInScope(string s) {
+    pair<Decl*,llvm::Value *> tmp = findSymbol(s);
+    return tmp.first != NULL;
+}
+
+bool isInScope(Decl* d) {
+    string s(d->GetIdentifier()->GetName());
+    return isInScope(s);
+}
+
+void pushScope() {
+    symbols.push_back(map<string,pair<Decl*,llvm::Value *> >());
+}
+void popScope() {
+    symbols.pop_back();
+}
+
+void addToScope(string s, Decl* d, Type* t) {
+    symbols[symbols.size()-1][s] = make_pair(d, t);
+}
diff --git a/ast.h b/ast.h
index 88562cd..b92d2f7 100644
--- a/ast.h
+++ b/ast.h
@@ -41,12 +41,16 @@
 #include "irgen.h"
 #include "location.h"
 #include <iostream>
+#include <vector>
+#include <map>
+#include <algorithm>
 
 using namespace std;
 
 class SymbolTable;
 class MyStack;
 class FnDecl;
+class Decl;
 
 class Node  {
   protected:
@@ -98,7 +102,20 @@ class Error : public Node
     Error() : Node() {}
     const char *GetPrintNameForNode()   { return "Error"; }
 };
-
+/*------------------------------------------------------------------------------------
+ * Symbol Table Information
+ *----------------------------------------------------------------------------------*/
+typedef vector<map<string,pair<Decl*,llvm::Value *> > > SymbolTable;
+pair<Decl*,llvm::Value * v> findSymbol(string s);
+pair<Decl*,llvm::Value * v> findSymbol(Decl* d);
+bool isInCurrentScope(string s);
+bool isInCurrentScope(Decl* d);
+bool isInScope(string s);
+bool isInScope(Decl* d);
+void pushScope();
+void popScope();
+void addToScope(string s, Decl* d, llvm::Value * v t);
+extern SymbolTable symbols;
 
 
 #endif
-- 
1.9.1