Changes to m4/doc/m4.texinfo,v [branch-1_4]

[Eric Blake]

CVSROOT:        /sources/m4
Module name:    m4
Branch:         branch-1_4
Changes by:     Eric Blake <ericb>      07/05/25 17:27:37

Index: doc/m4.texinfo
===================================================================
RCS file: /sources/m4/m4/doc/m4.texinfo,v
retrieving revision 1.1.1.1.2.124
retrieving revision 1.1.1.1.2.125
diff -u -b -r1.1.1.1.2.124 -r1.1.1.1.2.125
--- doc/m4.texinfo      25 May 2007 12:58:50 -0000      1.1.1.1.2.124
+++ doc/m4.texinfo      25 May 2007 17:27:36 -0000      1.1.1.1.2.125
@@ -664,7 +664,8 @@
 Synchronization directives are always given on complete lines by
 themselves.  When a synchronization discrepancy occurs in the middle of
 an output line, the associated synchronization directive is delayed
-until the beginning of the next generated line.
+until the next newline that does not occur in the middle of a quoted
+string or comment.
 
 @comment options: -s
 @example
@@ -672,15 +673,31 @@
 2')
 @result{}#line 2 "stdin"
 @result{}
+changecom(`/*', `*/')
address@hidden
+define(`comment', `/*1
+2*/')
address@hidden 5
address@hidden
 dnl no line
 hello
address@hidden 4
address@hidden 7
 @result{}hello
 twoline
 @result{}1
address@hidden 5
address@hidden 8
 @result{}2
+comment
address@hidden/*1
address@hidden/
+one comment `two
+three'
address@hidden 10
address@hidden /*1
address@hidden/ two
address@hidden
 goodbye
address@hidden 12
 @result{}goodbye
 @end example
 
@@ -6151,7 +6168,29 @@
 The sync line option is used mostly when using @code{m4} as
 a front end to a compiler.  If a diverted line causes a compiler error,
 the error messages should most probably refer to the place where the
-diversion were made, and not where it was inserted again.
+diversion was made, and not where it was inserted again.
+
address@hidden options: -s
address@hidden
+divert(2)2
+divert(1)1
+divert`'0
address@hidden 3 "stdin"
address@hidden
+^D
address@hidden 2 "stdin"
address@hidden
address@hidden 1 "stdin"
address@hidden
address@hidden example
+
+The current @code{m4} implementation has a limitation that the syncline
+output at the start of each diversion occurs no matter what, even if the
+previous diversion did not end with a newline.  This goes contrary to
+the claim that synclines appear on a line by themselves, so this
+limitation may be corrected in a future version of @code{m4}.  In the
+meantime, when using @option{-s}, it is wisest to make sure all
+diversions end with newline.
 
 @item
 @acronym{GNU} @code{m4} makes no attempt at prohibiting self-referential