Basic #include functionality imported

M2libc

@@ -1 +1 @@
-Subproject commit 222726e4f8d6b3898da41e6052a95b6599e1c864
+Subproject commit c684e9275ff4b8ef45a970990e0a2959cef9a8c5

cc_macro.c

@@ -568,7 +568,12 @@ void handle_define()
 			return;
 		}
 
-		require(NULL != hold, "#define got something it can't handle\n");
+		if(NULL == hold)
+		{
+			fputs("#define got something it can't handle\n", stderr);
+			line_error_token(macro_token);
+			exit(EXIT_FAILURE);
+		}
 
 		expansion_end = macro_token;
 

cc_reader.c

@@ -17,12 +17,40 @@
  */
 
 #include "cc.h"
+char* env_lookup(char* variable);
+char* int2str(int x, int base, int signed_p);
+
+struct visited
+{
+	struct visited* prev;
+	char* name;
+};
 
 /* Globals */
 FILE* input;
 struct token_list* token;
 int line;
 char* file;
+struct visited* vision;
+
+int previously_seen(char* s)
+{
+	struct visited* v = vision;
+	while(NULL != v)
+	{
+		if(match(v->name, s)) return TRUE;
+		v = v->prev;
+	}
+	return FALSE;
+}
+
+void just_seen(char* s)
+{
+	struct visited* hold = calloc(1, sizeof(struct visited));
+	hold->prev = vision;
+	hold->name = s;
+	vision = hold;
+}
 
 int grab_byte()
 {
@@ -93,7 +121,7 @@ int preserve_keyword(int c, char* S)
 void reset_hold_string()
 {
 	int i = string_index + 2;
-	while(0 != i)
+	while(0 <= i)
 	{
 		hold_string[i] = 0;
 		i = i - 1;
@@ -207,17 +235,30 @@ struct token_list* remove_preprocessor_directives(struct token_list* head)
 	return first;
 }
 
-int get_token(int c)
+void new_token(char* s, int size)
 {
 	struct token_list* current = calloc(1, sizeof(struct token_list));
 	require(NULL != current, "Exhausted memory while getting token\n");
 
+	/* More efficiently allocate memory for string */
+	current->s = calloc(size, sizeof(char));
+	require(NULL != current->s, "Exhausted memory while trying to copy a token\n");
+	copy_string(current->s, s, MAX_STRING);
+
+	current->prev = token;
+	current->next = token;
+	current->linenumber = line;
+	current->filename = file;
+	token = current;
+}
+
+int get_token(int c)
+{
 	reset_hold_string();
 	string_index = 0;
 
 	if(c == EOF)
 	{
-		free(current);
 		return c;
 	}
 	else if((32 == c) || (9 == c) || (c == '\n'))
@@ -314,16 +355,7 @@ int get_token(int c)
 		c = consume_byte(c);
 	}
 
-	/* More efficiently allocate memory for string */
-	current->s = calloc(string_index + 2, sizeof(char));
-	require(NULL != current->s, "Exhausted memory while trying to copy a token\n");
-	copy_string(current->s, hold_string, MAX_STRING);
-
-	current->prev = token;
-	current->next = token;
-	current->linenumber = line;
-	current->filename = file;
-	token = current;
+	new_token(hold_string, string_index + 2);
 	return c;
 }
 
@@ -341,6 +373,131 @@ struct token_list* reverse_list(struct token_list* head)
 	return root;
 }
 
+int read_include(int c)
+{
+	reset_hold_string();
+	string_index = 0;
+	int done = FALSE;
+	int ch;
+
+	while(!done)
+	{
+		if(c == EOF)
+		{
+			fputs("we don't support EOF as a filename in #include statements\n", stderr);
+			exit(EXIT_FAILURE);
+		}
+		else if((32 == c) || (9 == c) || (c == '\n'))
+		{
+			c = grab_byte();
+		}
+		else if(('"' == c) || ('<' == c))
+		{
+			if('<' == c) c = '>';
+			ch = c;
+			do
+			{
+				c = consume_byte(c);
+				require(EOF != c, "Unterminated filename in #include\n");
+			} while(c != ch);
+			if('>' == ch) hold_string[0] = '<';
+			done = TRUE;
+		}
+	}
+
+	/* with just a little extra to put in the matching at the end */
+	new_token(hold_string, string_index + 3);
+	return c;
+}
+
+struct token_list* read_all_tokens(FILE* a, struct token_list* current, char* filename);
+int include_file(int ch)
+{
+	/* The old state to restore to */
+	char* hold_filename = file;
+	FILE* hold_input = input;
+	char* hold_line;
+	int hold_number;
+
+	/* The new file to load */
+	char* new_filename;
+	FILE* new_file;
+
+	require(EOF != ch, "#include failed to receive filename\n");
+	/* Remove the #include */
+	token = token->next;
+
+	/* Get new filename */
+	read_include(ch);
+	ch = ' ';
+	new_filename = token->s;
+	/* Remove name from stream */
+	token = token->next;
+
+	/* Try to open the file */
+	if('<' == new_filename[0])
+	{
+		char* path = env_lookup("M2LIBC_PATH");
+		if(NULL == path) path = "./M2libc";
+		reset_hold_string();
+		strcat(hold_string, path);
+		strcat(hold_string, "/");
+		strcat(hold_string, new_filename + 1);
+		strcat(new_filename, ">");
+		new_file = fopen(hold_string, "r");
+	}
+	else
+	{
+		new_file = fopen(new_filename+1, "r");
+		strcat(new_filename, "\"");
+	}
+
+	/* prevent multiple visits */
+	if(previously_seen(new_filename)) return ch;
+	just_seen(new_filename);
+
+	/* special case this compatibility crap */
+	if(match("\"../gcc_req.h\"", new_filename) || match("\"gcc_req.h\"", new_filename)) return ch;
+
+	fputs("reading file: ", stderr);
+	fputs(new_filename, stderr);
+	fputc('\n', stderr);
+
+	/* catch garbage input */
+	if(NULL == new_file)
+	{
+		fputs("unable to read file: ", stderr);
+		fputs(new_filename, stderr);
+		fputs("\nAborting hard!\n", stderr);
+		exit(EXIT_FAILURE);
+	}
+
+
+	/* Replace token */
+	new_token("//", 4);
+	new_token(" // #FILENAME", 11);
+	new_token(new_filename, strlen(new_filename) + 2);
+	new_token("1", 3);
+	new_token("\n", 3);
+	/* make sure to store return line number right after include */
+	hold_line = int2str(line + 1, 10, FALSE);
+	hold_number = line + 1;
+	read_all_tokens(new_file, token, new_filename);
+
+	/* put back old file info */
+	new_token("//", 4);
+	new_token(" // #FILENAME", 11);
+	new_token(hold_filename, strlen(hold_filename)+2);
+	new_token(hold_line, strlen(hold_line)+2);
+	new_token("\n", 3);
+
+	/* resume reading old file */
+	input = hold_input;
+	line = hold_number;
+	file = hold_filename;
+	return ch;
+}
+
 struct token_list* read_all_tokens(FILE* a, struct token_list* current, char* filename)
 {
 	input  = a;
@@ -348,7 +505,11 @@ struct token_list* read_all_tokens(FILE* a, struct token_list* current, char* fi
 	file = filename;
 	token = current;
 	int ch = grab_byte();
-	while(EOF != ch) ch = get_token(ch);
+	while(EOF != ch)
+	{
+		ch = get_token(ch);
+		if(match("#include", token->s)) ch = include_file(ch);
+	}
 
 	return token;
 }