some changes to cminus for symtab

src/symtab.h

@@ -1,9 +1,7 @@
 /****************************************************/
 /* File: symtab.h                                   */
-/* Symbol table interface for the TINY compiler     */
-/* (allows only one symbol table)                   */
-/* Compiler Construction: Principles and Practice   */
-/* Kenneth C. Louden                                */
+/* Symbol table interface for the CMINUS COMPILER   */
+/* Modified by Yenru0                               */
 /****************************************************/
 
 #ifndef _SYMTAB_H_
@@ -11,22 +9,116 @@
 
 #include "globals.h"
 
-/* Procedure st_insert inserts line numbers and
- * memory locations into the symbol table
- * loc = memory location is inserted only the
- * first time, otherwise ignored
- */
-void st_insert( char * name, int lineno, int loc );
+/* SYMTAB_SIZE is the size of the hash table */
+#define SYMTAB_SIZE 211
 
-/* Function st_lookup returns the memory 
- * location of a variable or -1 if not found
+/* the list of line numbers of the source 
+ * code in which a variable is referenced
  */
-int st_lookup ( char * name );
+typedef struct LineListRec {
+    int lineno;
+    struct LineListRec *next;
+} *LineList;
 
-/* Procedure printSymTab prints a formatted 
+/* The record in the bucket lists for
+ * each variable, including name, 
+ * assigned memory location, and
+ * the list of line numbers in which
+ * it appears in the source code
+ */
+typedef struct BucketListRec {
+    char *name;
+    TreeNode *treeNode;
+    LineList lines;
+    ExpType type;
+    int memloc; /* memory location for variable */
+    struct BucketListRec *next;
+} *BucketList;
+
+typedef struct ScopeListRec {
+    char *name;
+    int depth;
+    struct ScopeListRec *parent;
+    BucketList hashTable[SYMTAB_SIZE];
+} *Scope;
+
+Scope scope_global;
+
+static Scope scope_list[SYMTAB_SIZE];
+static int size_list = 0;
+
+static Scope scope_stack[SYMTAB_SIZE];
+static int top_stack = -1;
+
+/**
+ * create a new scope with given name
+ * @param scope_name: name of the scope
+ * @return the created scope
+ */
+Scope scope_new(char *scope_name);
+/**
+ * pop the current scope from the scope stack 
+ */
+void pop_scope(void);
+/**
+ * push a scope into the scope stack
+ * @param scope: the scope to be pushed
+ */
+void push_scope(Scope scope);
+/**
+ * insert a scope into the scope list
+ */
+void insert_scope_to_list(Scope scope);
+/**
+ * get the top of the scope stack
+ * @return the current scope or NULL if the stack is empty
+ */
+Scope curr_scope(void);
+
+/**
+ * insert a variable into the symbol table
+ * or update a variable if it already exists
+ * @param scope_name name of the scope
+ * @param name name of the variable
+ * @param type type of the variable
+ * @param treeNode syntax tree node
+ * @param lineno line number of the variable
+ * @param loc memory location of the variable
+ * @return 0 if success, -1 if failure
+ */
+int st_try_insert(
+        char *scope_name,
+        char *name,
+        ExpType type,
+        TreeNode *treeNode,
+        int loc);
+
+/**
+ * lookup a variable in the current scope
+ * @param name name of the variable to lookup
+ * @return the bucket list entry of the variable or NULL if not found
+ */
+BucketList st_lookup_current(char *name);
+
+/**
+ * lookup a variable from the given scope
+ * @param name name of the variable to lookup
+ * @return the bucket list entry of the variable or NULL if not found
+ */
+BucketList st_lookup(char *name);
+
+/**
+ * find a scope from the scope list
+ * @param scope_name name of the scope to find
+ * @return the scope or NULL if not found
+ */
+Scope find_scope(char *scope_name);
+
+/** 
+ * Procedure printSymTab prints a formatted 
  * listing of the symbol table contents 
  * to the listing file
  */
-void printSymTab(FILE * listing);
+void printSymTab(FILE *listing);
 
 #endif