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[RFA] -no-integrated-cpp documentation

Message ID 4F5CB6C3.7010208@codesourcery.com
State New
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Commit Message

Sandra Loosemore March 11, 2012, 2:29 p.m. UTC 
While I've been cleaning up invoke.texi I noticed that the blurb about 
-no-integrated-cpp needed some copy-editing and markup changes.  Then I 
noticed that the description didn't make a whole lot of sense, and that 
it talked about what might happen in the hypothetical case that 
cc1/cc1plus/cc1obj are merged, which I think only further confused 
things.  And, I further noticed that this option was documented with the 
C Dialect Options instead of the Preprocessor Options, which is where 
users might be most likely to look for it.

I dug up the original discussion that led to this option being added 
back in 2003 -- it's here:

http://gcc.gnu.org/ml/gcc/2002-12/msg01163.html

Based on that and reading the code, I've tried to rewrite the 
documentation so it makes more sense.  Did I get this right?  If I'm 
understanding the intended purpose of this option correctly, it sounds 
like a really convoluted hack and maybe not what the manual ought to 
recommend.  (If you really want to do stuff with the preprocessed code 
before compiling it, why not just write a makefile rule or a shell 
script to use as your $(CC)?)  But, I think we have a gazillion other 
useless options too, and it's probably more trouble to remove than it's 
worth....

Anyway, I'd appreciate another pair of eyes looking at this, and 
suggestions on what better to do here if this rewrite isn't adequate.

-Sandra


2012-03-11  Sandra Loosemore  <sandra@codesourcery.com>

	gcc/
	* doc/invoke.texi (Option Summary): Move -no-integrated-cpp
	from C Language Options to Preprocessor Options.
	(C Dialect Options): Move -no-integrated-cpp documentation
	from here...
	(Preprocessor Options): ...to here.  Rewrite the description
	so it makes more sense, and remove discussion of merging
	front ends.

Comments

Joseph Myers March 12, 2012, 1:10 a.m. UTC | #1 
On Sun, 11 Mar 2012, Sandra Loosemore wrote:

> 2012-03-11  Sandra Loosemore  <sandra@codesourcery.com>
> 
> 	gcc/
> 	* doc/invoke.texi (Option Summary): Move -no-integrated-cpp
> 	from C Language Options to Preprocessor Options.
> 	(C Dialect Options): Move -no-integrated-cpp documentation
> 	from here...
> 	(Preprocessor Options): ...to here.  Rewrite the description
> 	so it makes more sense, and remove discussion of merging
> 	front ends.

OK.
diff mbox

Patch

Index: gcc/doc/invoke.texi
===================================================================
--- gcc/doc/invoke.texi	(revision 185168)
+++ gcc/doc/invoke.texi	(working copy)
@@ -174,7 +174,7 @@  in the following sections.
 -aux-info @var{filename} -fallow-parameterless-variadic-functions @gol
 -fno-asm  -fno-builtin  -fno-builtin-@var{function} @gol
 -fhosted  -ffreestanding -fopenmp -fms-extensions -fplan9-extensions @gol
--trigraphs  -no-integrated-cpp  -traditional  -traditional-cpp @gol
+-trigraphs  -traditional  -traditional-cpp @gol
 -fallow-single-precision  -fcond-mismatch -flax-vector-conversions @gol
 -fsigned-bitfields  -fsigned-char @gol
 -funsigned-bitfields  -funsigned-char}
@@ -433,7 +433,7 @@  Objective-C and Objective-C++ Dialects}.
 -M  -MM  -MF  -MG  -MP  -MQ  -MT  -nostdinc  @gol
 -P  -fdebug-cpp -ftrack-macro-expansion -fworking-directory @gol
 -remap -trigraphs  -undef  -U@var{macro}  @gol
--Wp,@var{option} -Xpreprocessor @var{option}}
+-Wp,@var{option} -Xpreprocessor @var{option} -no-integrated-cpp}
 
 @item Assembler Option
 @xref{Assembler Options,,Passing Options to the Assembler}.
@@ -1794,17 +1794,6 @@  supported for C, not C++.
 Support ISO C trigraphs.  The @option{-ansi} option (and @option{-std}
 options for strict ISO C conformance) implies @option{-trigraphs}.
 
-@item -no-integrated-cpp
-@opindex no-integrated-cpp
-Performs a compilation in two passes: preprocessing and compiling.  This
-option allows a user supplied "cc1", "cc1plus", or "cc1obj" via the
-@option{-B} option.  The user supplied compilation step can then add in
-an additional preprocessing step after normal preprocessing but before
-compiling.  The default is to use the integrated cpp (internal cpp)
-
-The semantics of this option will change if "cc1", "cc1plus", and
-"cc1obj" are merged.
-
 @cindex traditional C language
 @cindex C language, traditional
 @item -traditional
@@ -9300,6 +9289,21 @@  recognize.
 
 If you want to pass an option that takes an argument, you must use
 @option{-Xpreprocessor} twice, once for the option and once for the argument.
+
+@item -no-integrated-cpp
+@opindex no-integrated-cpp
+Perform preprocessing as a separate pass before compilation.
+By default, GCC performs preprocessing as an integrated part of
+input tokenization and parsing.
+If this option is provided, the appropriate language front end
+(@command{cc1}, @command{cc1plus}, or @command{cc1obj} for C, C++,
+and Objective-C, respectively) is instead invoked twice,
+once for preprocessing only and once for actual compilation
+of the preprocessed input.
+This option may be useful in conjunction with the @option{-B} or
+@option{-wrapper} options to specify an alternate preprocessor or
+perform additional processing of the program source between
+normal preprocessing and compilation.
 @end table
 
 @include cppopts.texi