1 files changed, 170 insertions, 63 deletions

diff --git a/gas/cond.c b/gas/cond.c
index 38aec6f..a87b4bc 100644
--- a/gas/cond.c
+++ b/gas/cond.c
@@ -1,128 +1,235 @@
 /* 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 2, 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.  */
 
-This file is part of GAS, the GNU Assembler.
+#include "as.h"
 
-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.
+#include "obstack.h"
 
-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.
+/* This is allocated to grow and shrink as .ifdef/.endif pairs are scanned. */
+struct obstack cond_obstack;
 
-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.  */
+struct file_line {
+	char *logical_file;
+	int logical_line;
+	char *physical_file;
+	int physical_line;
+}; /* file_line */
 
-/* static const char rcsid[] = "$Id$"; */
+/* This is what we push and pop. */
+struct conditional_frame {
+	struct file_line if_file_line;	/* the source file & line number of the "if" */
+	struct file_line else_file_line; /* the source file & line of the "else" */
+	struct conditional_frame *previous_cframe;
+	int else_seen; /* have we seen an else yet? */
+	int ignoring;	     /* if we are currently ignoring input. */
+	int dead_tree;	     /* if a conditional at a higher level is ignoring input. */
+}; /* conditional_frame */
 
-#include "as.h"
+#ifdef __STDC__
 
-#include "obstack.h"
+static void get_file_line(struct file_line *into);
+static void initialize_cframe(struct conditional_frame *cframe);
+static void set_file_line(struct file_line *from);
+
+#else
+
+static void get_file_line();
+static void initialize_cframe();
+static void set_file_line();
+
+#endif
+
+static struct conditional_frame *current_cframe = NULL;
 
 void s_ifdef(arg)
 int arg;
 {
-/*	register char c; */
-	register char *name;	/* points to name of symbol */
-	register struct symbol *	symbolP; /* Points to symbol */
+	register char *name; /* points to name of symbol */
+	register struct symbol *symbolP; /* Points to symbol */
+	struct conditional_frame cframe;
 	
 	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);
+		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);
-	}
+		initialize_cframe(&cframe);
+		cframe.ignoring = cframe.dead_tree && !((symbolP != 0) ^ arg);
+		current_cframe = (struct conditional_frame *) obstack_copy(&cond_obstack, &cframe, sizeof(cframe));
+	} /* if a valid identifyer name */
+	
+	return;
 } /* 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;
+	struct conditional_frame cframe;
 	
-	SKIP_WHITESPACE();		/* Leading whitespace is part of 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");
+	    || operand.X_subtract_symbol != NULL) {
+		as_bad("non-constant expression in \".if\" statement");
+	} /* bad condition */
 	
 	/* 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);
+	initialize_cframe(&cframe);
+	cframe.ignoring = cframe.dead_tree || !((operand.X_add_number != 0) ^ arg);
+	current_cframe = (struct conditional_frame *) obstack_copy(&cond_obstack, &cframe, sizeof(cframe));
+	return;
 } /* s_if() */
 
 void s_endif(arg)
 int arg;
 {
-	char *base = obstack_base(&cond_obstack);
-	char *ptr = obstack_next_free(&cond_obstack);
+	struct conditional_frame *hold;
 	
-	if (ptr-1 == base) {
-		as_bad("unbalanced .endif");
+	if (current_cframe == NULL) {
+		as_bad("\".endif\" without \".if\"");
 	} else {
-		obstack_free(&cond_obstack, ptr-1);
-		cond_obstack.object_base = base;
-	}
+		hold = current_cframe;
+		current_cframe = current_cframe->previous_cframe;
+		obstack_free(&cond_obstack, hold);
+	} /* if one pop too many */
+	
+	return;
 } /* 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");
+	if (current_cframe == NULL) {
+		as_bad(".else without matching .if - ignored");
+		
+	} else if (current_cframe->else_seen) {
+		struct file_line hold;
+		as_bad("duplicate \"else\" - ignored");
+		
+		get_file_line(&hold);
+		set_file_line(&current_cframe->else_file_line);
+		as_bad("here is the previous \"else\".");
+		set_file_line(&current_cframe->if_file_line);
+		as_bad("here is the matching \".if\".");
+		set_file_line(&hold);
+		
 	} else {
-		ptr[-1] = !ptr[-1];
-	}
+		get_file_line(&current_cframe->else_file_line);
+		
+		if (!current_cframe->dead_tree) {
+			current_cframe->ignoring = !current_cframe->ignoring;
+		} /* if not a dead tree */
+		
+		current_cframe->else_seen = 1;
+	} /* if error else do it */
+	
+	return;
 } /* s_else() */
 
 void s_ifeqs(arg)
 int arg;
 {
 	as_bad("ifeqs not implemented.");
+	
+	return;
 } /* s_ifeqs() */
 
 void s_end(arg)
 int arg;
 {
-	;
+	return;
 } /* 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);
+	char *ptr = obstack_next_free (&cond_obstack);
+	
+	/* We cannot ignore certain pseudo ops.  */
+	if (input_line_pointer[-1] == '.'
+	    && ((input_line_pointer[0] == 'i'
+		 && (!strncmp (input_line_pointer, "if", 2)
+		     || !strncmp (input_line_pointer, "ifdef", 5)
+		     || !strncmp (input_line_pointer, "ifndef", 6)))
+		|| (input_line_pointer[0] == 'e'
+		    && (!strncmp (input_line_pointer, "else", 4)
+			|| !strncmp (input_line_pointer, "endif", 5))))) {
+		return 0;
+	}
+	
+	return((current_cframe != NULL) && (current_cframe->ignoring));
 } /* ignore_input() */
 
+static void initialize_cframe(cframe)
+struct conditional_frame *cframe;
+{
+	memset(cframe, 0, sizeof(*cframe));
+	get_file_line(&(cframe->if_file_line));
+	cframe->previous_cframe = current_cframe;
+	cframe->dead_tree = current_cframe != NULL && current_cframe->ignoring;
+	
+	return;
+} /* initialize_cframe() */
+
+static void get_file_line(into)
+struct file_line *into;
+{
+	extern char *logical_input_file;
+	extern char *physical_input_file;
+	extern int logical_input_line;
+	extern int physical_input_line;
+	
+	into->logical_file = logical_input_file;
+	into->logical_line = logical_input_line;
+	into->physical_file = physical_input_file;
+	into->physical_line = physical_input_line;
+	
+	return;
+} /* get_file_line() */
+
+static void set_file_line(from)
+struct file_line *from;
+{
+	extern char *logical_input_file;
+	extern char *physical_input_file;
+	extern int logical_input_line;
+	extern int physical_input_line;
+	
+	logical_input_file = from->logical_file;
+	logical_input_line = from->logical_line;
+	physical_input_file = from->physical_file;
+	physical_input_line = from->physical_line;
+	return;
+} /* set_file_line() */
+
+/*
+ * Local Variables:
+ * fill-column: 131
+ * comment-column: 0
+ * End:
+ */
+
 /* end of cond.c */