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Small proj-cpplib.html update
- To: gcc-patches at gcc dot gnu dot org
- Subject: Small proj-cpplib.html update
- From: Neil Booth <NeilB at earthling dot net>
- Date: Tue, 19 Sep 2000 20:14:52 +0100
Covers recent work.
* htdocs/proj-cpplib.html: Update.
RCS file: /cvs/gcc/wwwdocs/htdocs/proj-cpplib.html,v
retrieving revision 1.9
diff -u -p -r1.9 proj-cpplib.html
--- proj-cpplib.html 2000/09/12 17:10:35 1.9
+++ proj-cpplib.html 2000/09/19 18:49:50
@@ -64,6 +64,23 @@ please read the rest of this document fi
standard conforming C/C++. Traditional mode is implemented by a
separate program, not by cpplib.
+<h2>Work recently completed</h2>
+ <li>We decided recently to make backslash, whitespace, newline a
+ line continuation (with a warning). This is almost always an
+ editing mistake, and causes floods of errors if rejected. The
+ new behaviour works everywhere - within comments, between
+ tokens, and within tokens.
+ <li>The lexical analyzer has been rehashed again. It is quite clean
+ now, still single-pass, and only steps backwards in the input
+ stream in one place - when handling trigraphs and escaped
+ newlines. This too should be fixable if necessary, and means
+ multibyte character and UCN escape support within cpplib should
+ now be fairly straight-forward.
@@ -98,15 +115,6 @@ separate program, not by cpplib.
a global limit on the number of files mapped into memory. I am
not aware of any system with this problem, it is purely
- <li>We decided recently to make backslash, whitespace, newline a
- line continuation (with a warning). This is almost always an
- editing mistake, and causes floods of errors if rejected. This
- has been implemented as a ten-line hack and the semantics are
- not quite right. It doesn't work in comments, and in running
- text a block comment can appear between the backslash and the
- newline, which is not intended. However, since this is only an
- error-recovery issue, fixing it is not critical.
<h2>Missing User-visible Features</h2>
@@ -144,10 +152,7 @@ separate program, not by cpplib.
implementation is extremely clever and could probably benefit
- <li>The lexical analyzer has been rewritten to be one-pass. Again,
- the new implementation is extremely clever and should be
- simplified. Also, it has not been tuned, and is usually in the
- top ten in profiles.
+ <li>The lexical analyzer needs to be profiled and tuned.
<li>We allocate lots of itty bitty items with malloc. Some work has
been done on aggregating these into big blocks, using obstacks,
@@ -288,10 +293,6 @@ sets.
<p>The Single Unix specification, and possibly also POSIX, provide the
<code>nl_langinfo</code> and <code>iconv</code> interfaces which
-mostly circumvent these limitations. There are still difficulties;
-for example, cpplib in several places wishes to walk backward through
-a string, which is not possible with <code>iconv</code>. It is,
+mostly circumvent these limitations.