From: Jan Djärv <jan.h.d@swipnet.se>
Date: Thu, 7 Feb 2008 12:47:00 +0000 (+0000)
Subject: Use "do...while (0)", not "if (1)..else" in macro definitions.
X-Git-Tag: emacs-pretest-23.0.90~8118
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=92413ef3a119c29af24901e66b393d3c69cc83b5;p=emacs.git

Use "do...while (0)", not "if (1)..else" in macro definitions.
---

diff --git a/src/ChangeLog b/src/ChangeLog
index 9fcc90c2391..396ce321f72 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,13 @@
+2008-02-07  Jim Meyering  <meyering@redhat.com>
+
+        Use "do...while (0)", not "if (1)..else" in macro definitions.
+        The latter provokes a warning from gcc about the empty else, when
+        followed by ";".  Also, without that trailing semicolon, it would
+        silently swallow up any following statement.
+        * syntax.h (SETUP_SYNTAX_TABLE):
+        (SETUP_SYNTAX_TABLE_FOR_OBJECT): Likewise.
+        * buffer.h (DECODE_POSITION): Likewise.
+
 2008-02-07  Jim Meyering  <meyering@redhat.com>
 
 	* lread.c [lint]: Don't include <sys/inode.h>.
diff --git a/src/buffer.h b/src/buffer.h
index 87d646f35fe..8345c8fa06f 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -266,7 +266,7 @@ extern void enlarge_buffer_text P_ ((struct buffer *, int));
    and store the charpos in CHARPOS and the bytepos in BYTEPOS.  */
 
 #define DECODE_POSITION(charpos, bytepos, pos)			\
-if (1)								\
+do								\
   {								\
     Lisp_Object __pos = (pos);					\
     if (NUMBERP (__pos))					\
@@ -282,7 +282,7 @@ if (1)								\
     else							\
       wrong_type_argument (Qinteger_or_marker_p, __pos);	\
   }								\
-else
+while (0)
 
 /* Return the address of byte position N in current buffer.  */
 
diff --git a/src/syntax.h b/src/syntax.h
index 5a5a8a96da3..1138dca9887 100644
--- a/src/syntax.h
+++ b/src/syntax.h
@@ -256,7 +256,7 @@ extern char syntax_code_spec[16];
  */
 
 #define SETUP_SYNTAX_TABLE(FROM, COUNT)					\
-if (1)									\
+do									\
   {									\
     gl_state.b_property = BEGV;						\
     gl_state.e_property = ZV + 1;					\
@@ -269,7 +269,7 @@ if (1)									\
         update_syntax_table ((COUNT) > 0 ? (FROM) : (FROM) - 1, (COUNT),\
 			     1, Qnil);					\
   }									\
-else
+while (0)
 
 /* Same as above, but in OBJECT.  If OBJECT is nil, use current buffer.
    If it is t, ignore properties altogether.
@@ -279,7 +279,7 @@ else
    So if it is a buffer, we set the offset field to BEGV.  */
 
 #define SETUP_SYNTAX_TABLE_FOR_OBJECT(OBJECT, FROM, COUNT)		\
-if (1)									\
+do									\
   {									\
     gl_state.object = (OBJECT);						\
     if (BUFFERP (gl_state.object))					\
@@ -314,7 +314,7 @@ if (1)									\
 			    + (COUNT > 0 ? 0 :  -1)),			\
 			   COUNT, 1, gl_state.object);			\
   }									\
-else
+while (0)
 
 struct gl_state_s
 {