X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/665f0c2454e4d935a2bb1f869f917a7e58003d28..108df813c466663f80ed3cd5c74ec114369863d7:/src/system.h?ds=sidebyside
diff --git a/src/system.h b/src/system.h
index 985bbbee..bd94c837 100644
--- a/src/system.h
+++ b/src/system.h
@@ -1,12 +1,11 @@
/* System-dependent definitions for Bison.
- Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free
- Software Foundation, Inc.
+ Copyright (C) 2000-2007, 2009-2012 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ This program 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.
+ 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
@@ -14,8 +13,7 @@
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, write to the Free Software Foundation,
- Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+ along with this program. If not, see . */
#ifndef BISON_SYSTEM_H
#define BISON_SYSTEM_H
@@ -68,13 +66,19 @@ typedef size_t uintptr_t;
| GCC extensions. |
`-----------------*/
-/* Use this to suppress gcc's `...may be used before initialized'
- warnings. */
-#ifdef lint
-# define IF_LINT(Code) Code
-#else
-# define IF_LINT(Code) /* empty */
-#endif
+/* Use PACIFY_CC to indicate that Code is unimportant to the logic of Bison
+ but that it is necessary for suppressing compiler warnings. For example,
+ Code might be a variable initializer that's always overwritten before the
+ variable is used.
+
+ PACIFY_CC is intended to be useful only as a comment as it does not alter
+ Code. It is tempting to redefine PACIFY_CC so that it will suppress Code
+ when configuring without --enable-gcc-warnings. However, that would mean
+ that, for maintainers, Bison would compile with potentially less warnings
+ and safer logic than it would for users. Due to the overhead of M4,
+ suppressing Code is unlikely to offer any significant improvement in
+ Bison's performance anyway. */
+#define PACIFY_CC(Code) Code
#ifndef __attribute__
/* This feature is available in gcc versions 2.5 and later. */
@@ -124,14 +128,26 @@ typedef size_t uintptr_t;
| Assertions. |
`-------------*/
-/* 's assertions are too heavyweight, and can be disabled
- too easily, so use aver rather than assert. */
-static inline void
-aver (bool assertion)
-{
- if (! assertion)
- abort ();
-}
+/* In the past, Bison defined aver to simply invoke abort in the case of
+ a failed assertion. The rationale was that 's assertions
+ were too heavyweight and could be disabled too easily. See
+ discussions at
+
+ .
+
+ However, normal assert output can be helpful during development and
+ in bug reports from users. Moreover, it's not clear now that
+ 's assertions are significantly heavyweight. Finally, if
+ users want to experiment with disabling assertions, it's debatable
+ whether it's our responsibility to stop them. See discussion
+ starting at
+ .
+
+ For now, we use assert but we call it aver throughout Bison in case
+ we later wish to try another scheme.
+*/
+#include
+#define aver assert
/*-----------.
@@ -145,32 +161,32 @@ aver (bool assertion)
#define obstack_sgrow(Obs, Str) \
obstack_grow (Obs, Str, strlen (Str))
-#define obstack_fgrow1(Obs, Format, Arg1) \
-do { \
- char buf[4096]; \
- sprintf (buf, Format, Arg1); \
- obstack_grow (Obs, buf, strlen (buf)); \
+#define obstack_fgrow1(Obs, Format, Arg1) \
+do { \
+ char buf[4096]; \
+ sprintf (buf, Format, Arg1); \
+ obstack_grow (Obs, buf, strlen (buf)); \
} while (0)
-#define obstack_fgrow2(Obs, Format, Arg1, Arg2) \
-do { \
- char buf[4096]; \
- sprintf (buf, Format, Arg1, Arg2); \
- obstack_grow (Obs, buf, strlen (buf)); \
+#define obstack_fgrow2(Obs, Format, Arg1, Arg2) \
+do { \
+ char buf[4096]; \
+ sprintf (buf, Format, Arg1, Arg2); \
+ obstack_grow (Obs, buf, strlen (buf)); \
} while (0)
-#define obstack_fgrow3(Obs, Format, Arg1, Arg2, Arg3) \
-do { \
- char buf[4096]; \
- sprintf (buf, Format, Arg1, Arg2, Arg3); \
- obstack_grow (Obs, buf, strlen (buf)); \
+#define obstack_fgrow3(Obs, Format, Arg1, Arg2, Arg3) \
+do { \
+ char buf[4096]; \
+ sprintf (buf, Format, Arg1, Arg2, Arg3); \
+ obstack_grow (Obs, buf, strlen (buf)); \
} while (0)
-#define obstack_fgrow4(Obs, Format, Arg1, Arg2, Arg3, Arg4) \
-do { \
- char buf[4096]; \
- sprintf (buf, Format, Arg1, Arg2, Arg3, Arg4); \
- obstack_grow (Obs, buf, strlen (buf)); \
+#define obstack_fgrow4(Obs, Format, Arg1, Arg2, Arg3, Arg4) \
+do { \
+ char buf[4096]; \
+ sprintf (buf, Format, Arg1, Arg2, Arg3, Arg4); \
+ obstack_grow (Obs, buf, strlen (buf)); \
} while (0)
@@ -197,14 +213,14 @@ do { \
| Free a linked list. |
`---------------------*/
-#define LIST_FREE(Type, List) \
-do { \
- Type *_node, *_next; \
- for (_node = List; _node; _node = _next) \
- { \
- _next = _node->next; \
- free (_node); \
- } \
+#define LIST_FREE(Type, List) \
+do { \
+ Type *_node, *_next; \
+ for (_node = List; _node; _node = _next) \
+ { \
+ _next = _node->next; \
+ free (_node); \
+ } \
} while (0)