--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwasm/input.c	Wed Jan 19 22:27:17 2011 -0700
@@ -0,0 +1,413 @@
+/*
+input.c
+
+Copyright © 2010 William Astle
+
+This file is part of LWTOOLS.
+
+LWTOOLS is free software: you can redistribute it and/or modify it under the
+terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later
+version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+more details.
+
+You should have received a copy of the GNU General Public License along with
+this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+This file is used to handle reading input files. It serves to encapsulate
+the entire input system to make porting to different media and systems
+less difficult.
+*/
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <lw_alloc.h>
+#include <lw_stringlist.h>
+#include <lw_string.h>
+#include "lwasm.h"
+
+/*
+Data type for storing input buffers
+*/
+
+enum input_types_e
+{
+	input_type_file,			// regular file, no search path
+	input_type_include,			// include path, start from "local"
+	input_type_string,			// input from a string
+
+	input_type_error			// invalid input type
+};
+
+struct input_stack
+{
+	struct input_stack *next;
+	int type;
+	void *data;
+	int data2;
+	char *filespec;
+};
+
+#define IS	((struct input_stack *)(as -> input_data))
+
+void input_init(asmstate_t *as)
+{
+	struct input_stack *t;
+
+	if (as -> file_dir)
+		lw_stack_destroy(as -> file_dir);
+	as -> file_dir = lw_stack_create(lw_free);
+	as -> includelist = lw_stack_create(lw_free);
+	lw_stringlist_reset(as -> input_files);
+	while (IS)
+	{
+		t = IS;
+		as -> input_data = IS -> next;
+		lw_free(t);
+	}
+}
+
+void input_pushpath(asmstate_t *as, char *fn)
+{
+	/* take apart fn into path and filename then push the path */
+	/* onto the current file path stack */
+	
+	/* also add it to the list of files included */
+	char *dn, *dp;
+	int o;
+
+	dn = lw_strdup(fn);
+	lw_stack_push(as -> includelist, dn);
+
+	dn = lw_strdup(fn);
+	dp = dn + strlen(dn);
+	
+	while (--dp != dn)
+	{
+		if (*dp == '/')
+			break;
+	}
+	if (*dp == '/')
+		*dp = '\0';
+	
+	if (dp == dn)
+	{
+		lw_free(dn);
+		dn = lw_strdup(".");
+		lw_stack_push(as -> file_dir, dn);
+		return;
+	}
+	dp = lw_strdup(dn);
+	lw_free(dn);
+	lw_stack_push(as -> file_dir, dp);
+}
+
+void input_openstring(asmstate_t *as, char *s, char *str)
+{
+	struct input_stack *t;
+	
+	t = lw_alloc(sizeof(struct input_stack));
+	t -> filespec = lw_strdup(s);
+
+	t -> type = input_type_string;
+	t -> data = lw_strdup(str);
+	t -> data2 = 0;
+	t -> next = IS;
+	as -> input_data = t;
+	t -> filespec = lw_strdup(s);
+}
+
+void input_open(asmstate_t *as, char *s)
+{
+	struct input_stack *t;
+	char *s2;
+	char *p, *p2;
+
+	t = lw_alloc(sizeof(struct input_stack));
+	t -> filespec = lw_strdup(s);
+
+	for (s2 = s; *s2 && (*s2 != ':'); s2++)
+		/* do nothing */ ;
+	if (!*s2)
+	{
+		t -> type = input_type_file;
+	}
+	else
+	{
+		char *ts;
+		
+		ts = lw_strndup(s, s2 - s);
+		s = s2 + 1;
+		if (!strcmp(ts, "include"))
+			t -> type = input_type_include;
+		else if (!strcmp(ts, "file"))
+			t -> type = input_type_file;
+		else
+			t -> type = input_type_error;
+		
+		lw_free(ts);
+	}
+	t -> next = as -> input_data;
+	as -> input_data = t;
+	
+	switch (IS -> type)
+	{
+	case input_type_include:
+		/* first check for absolute path and if so, skip path */
+		if (*s == '/')
+		{
+			/* absolute path */
+			IS -> data = fopen(s, "rb");
+			debug_message(as, 1, "Opening (abs) %s", s);
+			if (!IS -> data)
+			{
+				lw_error("Cannot open file '%s': %s", s, strerror(errno));
+			}
+			input_pushpath(as, s);
+			return;
+		}
+		
+		/* relative path, check relative to "current file" directory */
+		p = lw_stack_top(as -> file_dir);
+		0 == asprintf(&p2, "%s/%s", p, s);
+		debug_message(as, 1, "Open: (cd) %s\n", p2);
+		IS -> data = fopen(p2, "rb");
+		if (IS -> data)
+		{
+			input_pushpath(as, p2);
+			lw_free(p2);
+			return;
+		}
+		debug_message(as, 2, "Failed to open: (cd) %s (%s)\n", p2, strerror(errno));
+		lw_free(p2);
+
+		/* now check relative to entries in the search path */
+		lw_stringlist_reset(as -> include_list);
+		while (p = lw_stringlist_current(as -> include_list))
+		{
+			0 == asprintf(&p2, "%s/%s", p, s);
+		debug_message(as, 1, "Open (sp): %s\n", p2);
+			IS -> data = fopen(p2, "rb");
+			if (IS -> data)
+			{
+				input_pushpath(as, p2);
+				lw_free(p2);
+				return;
+			}
+		debug_message(as, 2, "Failed to open: (sp) %s (%s)\n", p2, strerror(errno));
+			lw_free(p2);
+			lw_stringlist_next(as -> include_list);
+		}
+		lw_error("Cannot open include file '%s': %s", s, strerror(errno));
+		break;
+		
+	case input_type_file:
+		debug_message(as, 1, "Opening (reg): %s\n", s);
+		IS -> data = fopen(s, "rb");
+
+		if (!IS -> data)
+		{
+			lw_error("Cannot open file '%s': %s", s, strerror(errno));
+		}
+		input_pushpath(as, s);
+		return;
+	}
+
+	lw_error("Cannot figure out how to open '%s'.", t -> filespec);
+}
+
+FILE *input_open_standalone(asmstate_t *as, char *s)
+{
+	char *s2;
+	FILE *fp;
+	char *p, *p2;
+
+	/* first check for absolute path and if so, skip path */
+	if (*s == '/')
+	{
+		/* absolute path */
+		debug_message(as, 2, "Open file (st abs) %s", s);
+		fp = fopen(s, "rb");
+		if (!fp)
+		{
+			return NULL;
+		}
+		return fp;
+	}
+
+	/* relative path, check relative to "current file" directory */
+	p = lw_stack_top(as -> file_dir);
+	0 == asprintf(&p2, "%s/%s", p, s);
+	debug_message(as, 2, "Open file (st cd) %s", p2);
+	fp = fopen(p2, "rb");
+	if (fp)
+	{
+		lw_free(p2);
+		return fp;
+	}
+	lw_free(p2);
+
+	/* now check relative to entries in the search path */
+	lw_stringlist_reset(as -> include_list);
+	while (p = lw_stringlist_current(as -> include_list))
+	{
+		0 == asprintf(&p2, "%s/%s", p, s);
+		debug_message(as, 2, "Open file (st ip) %s", p2);
+		fp = fopen(p2, "rb");
+		if (fp)
+		{
+			lw_free(p2);
+			return fp;
+		}
+		lw_free(p2);
+		lw_stringlist_next(as -> include_list);
+	}
+	
+	return NULL;
+}
+
+char *input_readline(asmstate_t *as)
+{
+	char *s;
+	char linebuff[2049];
+	int lbloc;
+	int eol = 0;
+	
+	/* if no file is open, open one */
+nextfile:
+	if (!IS) {
+		s = lw_stringlist_current(as -> input_files);
+		if (!s)
+			return NULL;
+		lw_stringlist_next(as -> input_files);
+		input_open(as, s);
+	}
+	
+	switch (IS -> type)
+	{
+	case input_type_file:
+	case input_type_include:
+		/* read from a file */
+		lbloc = 0;
+		for (;;)
+		{
+			int c, c2;
+			c = fgetc(IS -> data);
+			if (c == EOF)
+			{
+				if (lbloc == 0)
+				{
+					struct input_stack *t;
+					fclose(IS -> data);
+					lw_free(lw_stack_pop(as -> file_dir));
+					lw_free(IS -> filespec);
+					t = IS -> next;
+					lw_free(IS);
+					as -> input_data = t;
+					goto nextfile;
+				}
+				linebuff[lbloc] = '\0';
+				eol = 1;
+			}
+			else if (c == '\r')
+			{
+				linebuff[lbloc] = '\0';
+				eol = 1;
+				c2 = fgetc(IS -> data);
+				if (c2 == EOF)
+					c = EOF;  
+				else if (c2 != '\n')
+					ungetc(c2, IS -> data);  
+			}
+			else if (c == '\n')
+			{
+				linebuff[lbloc] = '\0';
+				eol = 1;
+				c2 = fgetc(IS -> data);
+				if (c2 == EOF)
+					c = EOF;  
+				else if (c2 != '\r')
+					ungetc(c2, IS -> data);  
+			}
+			else
+			{
+				if (lbloc < 2048)
+					linebuff[lbloc++] = c;
+			}
+			if (eol)
+			{
+				s = lw_strdup(linebuff);
+				return s;
+			}
+		}
+
+	case input_type_string:
+		/* read from a string */
+		if (((char *)(IS -> data))[IS -> data2] == '\0')
+		{
+			struct input_stack *t;
+			lw_free(IS -> data);
+			lw_free(IS -> filespec);
+			t = IS -> next;
+			lw_free(IS);
+			as -> input_data = t;
+			goto nextfile;
+		}
+		s = (char *)(IS -> data);
+		lbloc = 0;
+		for (;;)
+		{
+			int c;
+			c = s[IS -> data2];
+			if (c)
+				IS -> data2++;
+			if (c == '\0')
+			{
+				linebuff[lbloc] = '\0';
+				eol = 1;
+			}
+			else if (c == '\r')
+			{
+				linebuff[lbloc] = '\0';
+				eol = 1;
+				if (s[IS -> data2] == '\n')
+					IS -> data2++;
+			}
+			else if (c == '\n')
+			{
+				linebuff[lbloc] = '\0';
+				eol = 1;
+				if (s[IS -> data2] == '\r')
+					IS -> data2++;
+			}
+			else
+			{
+				if (lbloc < 2048)
+					linebuff[lbloc++] = c;
+			}
+			if (eol)
+			{
+				s = lw_strdup(linebuff);
+				return s;
+			}
+		}
+	
+	default:
+		lw_error("Problem reading from unknown input type");
+	}
+}
+
+char *input_curspec(asmstate_t *as)
+{
+	if (IS)
+		return IS -> filespec;
+	return NULL;
+}