Initial revision

1 files changed, 128 insertions, 0 deletions

diff --git a/gas/cond.c b/gas/cond.c
new file mode 100644
index 0000000..38aec6f
--- /dev/null
+++ b/gas/cond.c
@@ -0,0 +1,128 @@
+/* cond.c - conditional assembly pseudo-ops, and .include
+   Copyright (C) 1990, 1991 Free Software Foundation, Inc.
+
+This file is part of GAS, the GNU Assembler.
+
+GAS 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 1, or (at your option)
+any later version.
+
+GAS 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 GAS; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* static const char rcsid[] = "$Id$"; */
+
+#include "as.h"
+
+#include "obstack.h"
+
+void s_ifdef(arg)
+int arg;
+{
+/*	register char c; */
+	register char *name;	/* points to name of symbol */
+	register struct symbol *	symbolP; /* Points to symbol */
+	
+	SKIP_WHITESPACE();		/* Leading whitespace is part of operand. */
+	name = input_line_pointer;
+	if (!is_name_beginner(*name)) {
+		as_bad("invalid identifier for .ifdef");
+		obstack_1grow (&cond_obstack, 0);
+	} else {
+		get_symbol_end();
+		++input_line_pointer;
+		symbolP = symbol_find(name);
+		
+		/* ??? Should we try to optimize such that if we hit a .endif
+		   before a .else, we don't need to push state?  */
+		obstack_1grow(&cond_obstack, (symbolP != 0) ^ arg);
+	}
+} /* s_ifdef() */
+
+/* This is allocated to grow and shrink as .ifdef/.endif pairs
+   are scanned.  When the top element is nonzero, it means
+   we should accept input.  Otherwise, we should ignore input.  */
+struct obstack cond_obstack;
+
+void s_if(arg)
+int arg;
+{
+	expressionS operand;
+	
+	SKIP_WHITESPACE();		/* Leading whitespace is part of operand. */
+	expr(0, &operand);
+	
+	if (operand.X_add_symbol != NULL
+	    || operand.X_subtract_symbol != NULL)
+	    as_bad("non-constant expression in .if statement");
+	
+	/* If the above error is signaled, this will dispatch
+	   using an undefined result.  No big deal.  */
+	obstack_1grow(&cond_obstack, (operand.X_add_number != 0) ^ arg);
+} /* s_if() */
+
+void s_endif(arg)
+int arg;
+{
+	char *base = obstack_base(&cond_obstack);
+	char *ptr = obstack_next_free(&cond_obstack);
+	
+	if (ptr-1 == base) {
+		as_bad("unbalanced .endif");
+	} else {
+		obstack_free(&cond_obstack, ptr-1);
+		cond_obstack.object_base = base;
+	}
+} /* s_endif() */
+
+void s_else(arg)
+int arg;
+{
+	char *ptr = obstack_next_free(&cond_obstack);
+	if (ptr-1 == obstack_base(&cond_obstack)) {
+		as_bad(".else without matching .if");
+	} else {
+		ptr[-1] = !ptr[-1];
+	}
+} /* s_else() */
+
+void s_ifeqs(arg)
+int arg;
+{
+	as_bad("ifeqs not implemented.");
+} /* s_ifeqs() */
+
+void s_end(arg)
+int arg;
+{
+	;
+} /* s_end() */
+
+int ignore_input() {
+  char *ptr = obstack_next_free (&cond_obstack);
+
+  /* We cannot ignore certain pseudo ops.  */
+  if (input_line_pointer[-1] == '.')
+    {
+      if (input_line_pointer[0] == 'i'
+	  && (!strncmp (input_line_pointer, "if", 2)
+	      || !strncmp (input_line_pointer, "ifdef", 5)
+	      || !strncmp (input_line_pointer, "ifndef", 6)))
+	return 0;
+      if (input_line_pointer[0] == 'e'
+	  && (!strncmp (input_line_pointer, "else", 4)
+	      || !strncmp (input_line_pointer, "endif", 5)))
+	return 0;
+    }
+
+  return (ptr[-1] == 0);
+} /* ignore_input() */
+
+/* end of cond.c */