--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwasm/pragma.c	Fri Jan 30 04:01:55 2009 +0000
@@ -0,0 +1,123 @@
+/*
+pragma.c
+Copyright © 2008 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/>.
+
+
+This file contains stuff associated with lwasm specific strangeness
+*/
+
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include "lwasm.h"
+#include "instab.h"
+
+/*
+A pragma is a means of controlling code generation.
+
+The pseudo op "*pragma" which will be treated as a comment by an assembler
+that doesn't recognize it and thus will not cause assembly errors. This is
+the preferred way of flagging a pragma if it will not cause incorrect
+execution of the program.
+
+The pseudo op "pragma" which will cause an error on an assembler that does
+not understand it.
+
+In the case of "*pragma", unrecognized pragmas MUST be silently ignored. In
+the case of "pragma", unrecognized pragmas should raise an error.
+
+LWASM understands the following pragmas:
+
+index0tonone
+noindex0tonone
+
+When set (index0tonone), an expression that evaluates to 0, other than a
+bare constant, in a <offset>,r operand will cause the code for ",r" to be
+emitted rather than "0,r". If not set (noindex0tonone), the "0,r" output
+will be emitted. The default is to perform the optimization.
+
+This particular optimization will save a cycle for a direct operation. For
+an indirect operation, however, it will save several cycles and a program byte
+which may be very useful.
+*/
+
+void pseudo_pragma_real(asmstate_t *as, lwasm_line_t *cl, char **optr, int error)
+{
+	char pragma[128];
+	int c = 0;
+	
+	while (isspace(**optr))
+		(*optr)++;
+	
+	while (c < 127 && **optr && !isspace(**optr))
+	{
+		pragma[c++] = **optr;
+		(*optr)++;
+	}
+	
+	if (c == 0 || (**optr && !isspace(**optr)))
+	{
+		if (error)
+		{
+			register_error(as, cl, 1, "Unrecognized pragma");
+		}
+		if (error == 2)
+		{
+			*optr = NULL;
+		}
+		return;
+	}
+	pragma[c] = 0;
+	if (!strcasecmp(pragma, "noindex0tonone"))
+	{
+		as -> pragmas |= PRAGMA_NOINDEX0TONONE;
+	}
+	else if (!strcasecmp(pragma, "index0tonone"))
+	{
+		as -> pragmas &= ~PRAGMA_NOINDEX0TONONE;
+	}
+	else if (!strcasecmp(pragma, "undefextern"))
+	{
+		as -> pragmas |= PRAGMA_UNDEFEXTERN;
+	}
+	else if (!strcasecmp(pragma, "noundefextern"))
+	{
+		as -> pragmas &= ~PRAGMA_UNDEFEXTERN;
+	}
+	else
+	{
+		if (error)
+		{
+			register_error(as, cl, 1, "Unrecognized pragma");
+			if (error == 2)
+			{
+				*optr = NULL;
+			}
+		}
+	}
+}
+
+OPFUNC(pseudo_pragma)
+{
+	pseudo_pragma_real(as, l, p, 1);
+}
+
+OPFUNC(pseudo_starpragma)
+{
+	pseudo_pragma_real(as, l, p, 0);
+}