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| author | Neil Booth <neilb@earthling.net> | 2000-07-11 13:39:09 +0000 |
|---|---|---|
| committer | Neil Booth <neil@gcc.gnu.org> | 2000-07-11 13:39:09 +0000 |
| commit | 745ef6d6ec2c9a2ad6ff6876587dc4ad122c117a (patch) | |
| tree | 27fe1cb190ef955be8859810e58dc63872164bde /gcc/cpp.texi | |
| parent | 9b55f29a8432a6e841ad1e842585666562c6eca3 (diff) | |
| download | gcc-745ef6d6ec2c9a2ad6ff6876587dc4ad122c117a.zip gcc-745ef6d6ec2c9a2ad6ff6876587dc4ad122c117a.tar.gz gcc-745ef6d6ec2c9a2ad6ff6876587dc4ad122c117a.tar.bz2 | |
cpp.texi: Update.
* cpp.texi: Update.
* gcc.dg/cpp/cmdlne-C.c: New test.
From-SVN: r34957
Diffstat (limited to 'gcc/cpp.texi')
| -rw-r--r-- | gcc/cpp.texi | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/gcc/cpp.texi b/gcc/cpp.texi index 74270d0..0e30e1d 100644 --- a/gcc/cpp.texi +++ b/gcc/cpp.texi @@ -83,9 +83,9 @@ It is called a macro processor because it allows you to define The C preprocessor is intended only for macro processing of C, C++ and Objective C source files. For macro processing of other files, you are strongly encouraged to use alternatives like M4, which will likely give -you better results and avoid many problems. For example, the C -preprocessor sometimes outputs extra white space to avoid inadvertent C -token concatenation, and this may cause problems with other languages. +you better results and avoid many problems. For example, normally the C +preprocessor does not preserve arbitrary whitespace verbatim, but +instead replaces each sequence with a single space. For use on C-like source files, the C preprocessor provides four separate facilities that you can use as you see fit: @@ -2908,11 +2908,14 @@ and will be sent to a program which might be confused by the @item -C @findex -C -Do not discard comments: pass them through to the output file. -Comments appearing in arguments of a macro call will be copied to the -output before the expansion of the macro call. - -You should be prepared for unwanted side effects when using -C. For +Do not discard comments. All comments are passed through to the output +file, except for comments in processed directives, which are deleted +along with the directive. Comments appearing in the expansion list of a +macro will be preserved, and appear in place wherever the macro is +invoked. + +You should be prepared for side effects when using -C; it causes the +preprocessor to treat comments as tokens in their own right. For example, macro redefinitions that were trivial when comments were replaced by a single space might become significant when comments are retained. Also, comments appearing at the start of what would be a |