diff old-trunk/lwasm/old/output.c @ 339:eb230fa7d28e

Prepare for migration to hg
author lost
date Fri, 19 Mar 2010 02:54:14 +0000
parents
children
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/old-trunk/lwasm/old/output.c	Fri Mar 19 02:54:14 2010 +0000
@@ -0,0 +1,458 @@
+/*
+output.c
+Copyright © 2009 William Astle
+
+This file is part of LWASM.
+
+LWASM 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/>.
+
+
+Contains the code for actually outputting the assembled code
+*/
+#include <config.h>
+//#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+//#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#define __output_c_seen__
+//#include "instab.h"
+#include "lwasm.h"
+#include "util.h"
+
+void write_code_raw(asmstate_t *as, FILE *of);
+void write_code_decb(asmstate_t *as, FILE *of);
+void write_code_rawrel(asmstate_t *as, FILE *of);
+void write_code_obj(asmstate_t *as, FILE *of);
+void write_code_os9(asmstate_t *as, FILE *of);
+
+// this prevents warnings about not using the return value of fwrite()
+#define writebytes(s, l, c, f)	do { int r; r = fwrite((s), (l), (c), (f)); } while (0)
+
+void lwasm_output(asmstate_t *as)
+{
+	FILE *of;
+	
+	if (as -> errorcount > 0)
+	{
+		fprintf(stderr, "Not doing output due to assembly errors.\n");
+		return;
+	}
+	
+	of = fopen(as -> outfile, "wb");
+	if (!of)
+	{
+		fprintf(stderr, "Cannot open '%s' for output", as -> outfile);
+		perror("");
+		return;
+	}
+
+	switch (as -> outformat)
+	{
+	case OUTPUT_RAW:
+		write_code_raw(as, of);
+		break;
+		
+	case OUTPUT_DECB:
+		write_code_decb(as, of);
+		break;
+		
+	case OUTPUT_RAWREL:
+		write_code_rawrel(as, of);
+		break;
+	
+	case OUTPUT_OBJ:
+		write_code_obj(as, of);
+		break;
+
+	case OUTPUT_OS9:
+		write_code_os9(as, of);
+		break;
+
+	default:
+		fprintf(stderr, "BUG: unrecognized output format when generating output file\n");
+		fclose(of);
+		unlink(as -> outfile);
+		return;
+	}
+
+	fclose(of);
+}
+
+/*
+rawrel output treats an ORG directive as an offset from the start of the
+file. Undefined results will occur if an ORG directive moves the output
+pointer backward. This particular implementation uses "fseek" to handle
+ORG requests and to skip over RMBs.
+
+This simple brain damanged method simply does an fseek before outputting
+each instruction.
+*/
+void write_code_rawrel(asmstate_t *as, FILE *of)
+{
+	lwasm_line_t *cl;
+	
+	for (cl = as -> lineshead; cl; cl = cl -> next)
+	{
+		if (cl -> codelen == 0)
+			continue;
+		
+		fseek(of, cl -> codeaddr, SEEK_SET);
+		writebytes(cl -> bytes, cl -> codelen, 1, of);
+	}
+}
+
+/*
+raw merely writes all the bytes directly to the file as is. ORG is just a
+reference for the assembler to handle absolute references. Multiple ORG
+statements will produce mostly useless results
+*/
+void write_code_raw(asmstate_t *as, FILE *of)
+{
+	lwasm_line_t *cl;
+	
+	for (cl = as -> lineshead; cl; cl = cl -> next)
+	{
+		if (cl -> nocodelen)
+		{
+			int i;
+			for (i = 0; i < cl -> nocodelen; i++)
+				writebytes("\0", 1, 1, of);
+			continue;
+		}
+		writebytes(cl -> bytes, cl -> codelen, 1, of);
+	}
+}
+
+
+/*
+OS9 target also just writes all the bytes in order. No need for anything
+else.
+*/
+void write_code_os9(asmstate_t *as, FILE *of)
+{
+	lwasm_line_t *cl;
+	
+	for (cl = as -> lineshead; cl; cl = cl -> next)
+	{
+		if (cl -> inmod == 0)
+			continue;
+		if (cl -> nocodelen)
+		{
+			int i;
+			for (i = 0; i < cl -> nocodelen; i++)
+				writebytes("\0", 1, 1, of);
+			continue;
+		}
+		writebytes(cl -> bytes, cl -> codelen, 1, of);
+	}
+}
+
+void write_code_decb(asmstate_t *as, FILE *of)
+{
+	long preambloc;
+	lwasm_line_t *cl;
+	int blocklen = -1;
+	int nextcalc = -1;
+	unsigned char outbuf[5];
+	
+	for (cl = as -> lineshead; cl; cl = cl -> next)
+	{
+		if (cl -> nocodelen)
+			continue;
+		if (cl -> codeaddr != nextcalc && cl -> codelen > 0)
+		{
+			// need preamble here
+			if (blocklen > 0)
+			{
+				// update previous preamble if needed
+				fseek(of, preambloc, SEEK_SET);
+				outbuf[0] = (blocklen >> 8) & 0xFF;
+				outbuf[1] = blocklen & 0xFF;
+				writebytes(outbuf, 2, 1, of);
+				fseek(of, 0, SEEK_END);
+			}
+			blocklen = 0;
+			nextcalc = cl -> codeaddr;
+			outbuf[0] = 0x00;
+			outbuf[1] = 0x00;
+			outbuf[2] = 0x00;
+			outbuf[3] = (nextcalc >> 8) & 0xFF;
+			outbuf[4] = nextcalc & 0xFF;
+			preambloc = ftell(of) + 1;
+			writebytes(outbuf, 5, 1, of);
+		}
+		nextcalc += cl -> codelen;
+		writebytes(cl -> bytes, cl -> codelen, 1, of);
+		blocklen += cl -> codelen;
+	}
+	if (blocklen > 0)
+	{
+		fseek(of, preambloc, SEEK_SET);
+		outbuf[0] = (blocklen >> 8) & 0xFF;
+		outbuf[1] = blocklen & 0xFF;
+		writebytes(outbuf, 2, 1, of);
+		fseek(of, 0, SEEK_END);
+	}
+	
+	// now write postamble
+	outbuf[0] = 0xFF;
+	outbuf[1] = 0x00;
+	outbuf[2] = 0x00;
+	outbuf[3] = (as -> execaddr >> 8) & 0xFF;
+	outbuf[4] = (as -> execaddr) & 0xFF;
+	writebytes(outbuf, 5, 1, of);
+}
+
+void write_code_obj_sbadd(sectiontab_t *s, unsigned char b)
+{
+	if (s -> oblen >= s -> obsize)
+	{
+		s -> obytes = lwasm_realloc(s -> obytes, s -> obsize + 128);
+		s -> obsize += 128;
+	}
+	s -> obytes[s -> oblen] = b;
+	s -> oblen += 1;
+}
+
+void write_code_obj(asmstate_t *as, FILE *of)
+{
+	lwasm_line_t *l;
+	sectiontab_t *s;
+	lwasm_symbol_ent_t *se;
+	export_list_t *ex;
+	section_reloc_list_t *re;
+	lwasm_expr_stack_node_t *sn;			
+	
+	int i;
+	unsigned char buf[16];
+
+	// output the magic number and file header
+	// the 8 is NOT an error
+	writebytes("LWOBJ16", 8, 1, of);
+	
+	// run through the entire system and build the byte streams for each
+	// section; at the same time, generate a list of "local" symbols to
+	// output for each section
+	// NOTE: for "local" symbols, we will append \x01 and the ascii string
+	// of the context identifier (so sym in context 1 would be "sym\x011"
+	// we can do this because the linker can handle symbols with any
+	// character other than NUL.
+	// also we will generate a list of incomplete references for each
+	// section along with the actual definition that will be output
+	
+	// once all this information is generated, we will output each section
+	// to the file
+	
+	// NOTE: we build everything in memory then output it because the
+	// assembler accepts multiple instances of the same section but the
+	// linker expects only one instance of each section in the object file
+	// so we need to collect all the various pieces of a section together
+	// (also, the assembler treated multiple instances of the same section
+	// as continuations of previous sections so we would need to collect
+	// them together anyway.
+	
+	for (l = as -> lineshead; l; l = l -> next)
+	{
+		if (l -> sect)
+		{
+			// we're in a section - need to output some bytes
+			for (i = 0; i < l -> codelen; i++)
+				write_code_obj_sbadd(l -> sect, l -> bytes[i]);
+			for (i = 0; i < l -> nocodelen; i++)
+				write_code_obj_sbadd(l -> sect, 0);
+			
+			// do we have a "relocation"? If so, add a reference to the
+			// relocation table
+			if (l -> relocoff >= 0)
+			{
+				// build the relocation reference for the linker
+				re = lwasm_alloc(sizeof(section_reloc_list_t));
+				re -> next = l -> sect -> rl;
+				l -> sect -> rl = re;
+				
+				re -> offset = l -> codeaddr + l -> relocoff;
+				re -> expr = l -> exprs[0];
+				re -> context = l -> context;
+				re -> relocsize = 2;
+				if (l -> reloc8bit)
+					re -> relocsize = 1;
+			}
+		}
+	}
+	
+	// run through the sections
+	for (s = as -> sections; s; s = s -> next)
+	{
+		// write the name
+		writebytes(s -> name, strlen(s -> name) + 1, 1, of);
+		
+		// write the flags
+		if (s -> flags & SECTION_BSS)
+			writebytes("\x01", 1, 1, of);
+		
+		// indicate end of flags - the "" is NOT an error
+		writebytes("", 1, 1, of);
+		
+		
+		// now the local symbols
+		for (se = as -> symhead; se; se = se -> next)
+		{
+			// ignore symbols not in this section
+			if (se -> sect != s)
+				continue;
+			
+			if (se -> flags & SYMBOL_SET)
+				continue;
+			
+			if (se -> flags & SYMBOL_EXTERN)
+				continue;
+			
+			writebytes(se -> sym, strlen(se -> sym), 1, of);
+			if (se -> context >= 0)
+			{
+				writebytes("\x01", 1, 1, of);
+				sprintf(buf, "%d", se -> context);
+				writebytes(buf, strlen(buf), 1, of);
+			}
+			// the "" is NOT an error
+			writebytes("", 1, 1, of);
+			
+			// write the address
+			buf[0] = (se -> value >> 8) & 0xff;
+			buf[1] = se -> value & 0xff;
+			writebytes(buf, 2, 1, of);
+		}	
+		// flag end of local symbol table - "" is NOT an error
+		writebytes("", 1, 1, of);
+		
+		// now the exports
+		for (ex = s -> exports; ex; ex = ex -> next)
+		{
+			writebytes(ex -> sym, strlen(ex -> sym) + 1, 1, of);
+			buf[0] = (ex -> offset >> 8) & 0xff;
+			buf[1] = ex -> offset & 0xff;
+			writebytes(buf, 2, 1, of);
+		}
+		
+		// flag end of exported symbols - "" is NOT an error
+		writebytes("", 1, 1, of);
+		
+		// now output the "incomplete references"
+		// this being the most complex bit
+		for (re = s -> rl; re; re = re -> next)
+		{
+			if (re -> expr == NULL)
+			{
+				// this is an error but we'll simply ignore it
+				// and not output this expression
+				continue;
+			}
+			
+			// work through each term in the expression and output
+			// the proper equivalent to the object file
+			if (re -> relocsize == 1)
+			{
+				// flag an 8 bit relocation (low 8 bits will be used)
+				buf[0] = 0xFF;
+				buf[1] = 0x01;
+				writebytes(buf, 2, 1, of);
+			}
+			for (sn = re -> expr -> head; sn; sn = sn -> next)
+			{
+				switch (sn -> term -> term_type)
+				{
+				case LWASM_TERM_OPER:
+					buf[0] =  0x04;
+					buf[1] = sn -> term -> value;
+					writebytes(buf, 2, 1, of);
+					break;
+					
+				case LWASM_TERM_INT:
+					buf[0] = 0x01;
+					buf[1] = (sn -> term -> value >> 8) & 0xff;
+					buf[2] = sn -> term -> value & 0xff;
+					writebytes(buf, 3, 1, of);
+					break;
+				
+				case LWASM_TERM_SECBASE:
+					writebytes("\x05", 1, 1, of);
+					break;
+
+				case LWASM_TERM_SYM:
+					// now for the ugly part - resolve a symbol reference
+					// and determine whether it's internal, external, or
+					// a section base
+					se = lwasm_find_symbol(as, sn -> term -> symbol, re -> context);
+					if (!se)
+						se = lwasm_find_symbol(as, sn -> term -> symbol, -1);
+					if (!se || se -> flags & SYMBOL_EXTERN)
+					{
+						// not found - assume external reference
+						// found but flagged external - handle it
+						writebytes("\x02", 1, 1, of);
+						writebytes(se -> sym, strlen(se -> sym) + 1, 1, of);
+						break;
+					}
+					// a local symbol reference here
+					writebytes("\x03", 1, 1, of);
+					writebytes(se -> sym, strlen(se -> sym), 1, of);
+					if (se -> context >= 0)
+					{
+						writebytes("\x01", 1, 1, of);
+						sprintf(buf, "%d", se -> context);
+						writebytes(buf, strlen(buf), 1, of);
+					}
+					writebytes("", 1, 1, of);
+					break;
+
+				default:
+					// unrecognized term type - replace with integer 0
+					buf[0] = 0x01;
+					buf[1] = 0x00;
+					buf[2] = 0x00;
+					writebytes(buf, 3, 1, of);
+					break;
+				}
+			}
+			
+			// flag end of expressions
+			writebytes("", 1, 1, of);
+			
+			// write the offset
+			buf[0] = (re -> offset >> 8) & 0xff;
+			buf[1] = re -> offset & 0xff;
+			writebytes(buf, 2, 1, of);
+		}
+		// flag end of incomplete references list
+		writebytes("", 1, 1, of);
+		
+		// now blast out the code
+		
+		// length
+		buf[0] = s -> oblen >> 8 & 0xff;
+		buf[1] = s -> oblen & 0xff;
+		writebytes(buf, 2, 1, of);
+		
+		if (!(s -> flags & SECTION_BSS))
+		{
+			writebytes(s -> obytes, s -> oblen, 1, of);
+		}
+	}
+	
+	// flag no more sections
+	// the "" is NOT an error
+	writebytes("", 1, 1, of);
+}