Fix defines involving both literals and other defined macros.

We now store a list of tokens in our hash-table rather than a single
string. This lets us replace each macro in the value as necessary.

This code adds a link dependency on talloc which does exactly what we
want in terms of memory management for a parser.

The 3 tests added in the previous commit now pass.

glcpp.h

@@ -26,22 +26,31 @@
 
 #include "hash_table.h"
 
-#define YYSTYPE char *
 #define yyscan_t void*
 
-typedef struct {
-	yyscan_t scanner;
-	struct hash_table *defines;
-} glcpp_parser_t;
+/* Some data types used for parser value. */
 
-void
-glcpp_parser_init (glcpp_parser_t *parser);
+
+typedef struct node {
+	const char *str;
+	struct node *next;
+} node_t;
+
+typedef struct list {
+	node_t *head;
+	node_t *tail;
+} list_t;
+
+typedef struct glcpp_parser glcpp_parser_t;
+
+glcpp_parser_t *
+glcpp_parser_create (void);
 
 int
 glcpp_parser_parse (glcpp_parser_t *parser);
 
 void
-glcpp_parser_fini (glcpp_parser_t *parser);
+glcpp_parser_destroy (glcpp_parser_t *parser);
 
 /* Generated by glcpp-lex.l to glcpp-lex.c */