部分preprocess C或C ++源文件？ [英] Partially preprocess a C or C++ source file?

问题描述

是否有部分pre-过程中的 C 或C ++源文件的方法吗？所谓部分preprocess我的意思是扩大一些，但不是所有的#include指令。例如，我想扩大＃包括指着我的头的项目，而不是指向其他库头文件的#includes。

Is there a way to partially pre-process a C or C++ source file? By "partially preprocess" I mean expanding some but not all of the #include directives. For example, I would like to expand #includes pointing to my project headers, but not #includes pointing to other libraries' headers.

我试图做到这一点通过运行的gcc -E 仅在 -I 标记为我的项目标题和不是 -I 标志库，但是，这并不工作，因为gcc时遇到的#include它不能扩展提供了一个错误。

I tried to do this by running gcc -E with only the -I flags for my project headers and not the -I flags for the libraries, but that doesn't work because gcc gives an error when it encounters an #include it cannot expand.

修改：我真的不关心preprocessor的相对于宏扩展行为

EDIT: I do not really care about the preprocessor's behaviour with respect to macro expansion.

推荐答案

的C preprocessor是不是足够聪明，这样做对自己。如果你只在的#include 感兴趣的话，你应该推出自己的工具（在譬如Perl）来处理的源文件，扩大了的#include 行你感兴趣，而忽略休息。

The C preprocessor isn't smart enough to do this on its own. If you're only interested in #include, you should just roll your own tool (in, say, Perl) to process the source files, expanding #include lines that interest you and ignoring the rest.

本脚本prefixes无趣标题行与 //忽略：

This script prefixes uninteresting header lines with // Ignored:

#!/usr/bin/perl

use warnings;
use strict;

my @uninteresting = qw(iostream vector map);
my $uninteresting = join '|', @uninteresting;

while (<>) {
    s%(#include <(?:$uninteresting)>)%// Ignored $1%;
    print;
}

现在你可以这样做：

cat sourcefile.cpp | perl ignore-meh.pl | g++ -E

如果你想获得真正看中的：

And if you want to get really fancy:

#!/usr/bin/perl

use warnings;
use strict;

while (<>) {
    s%// Ignored (#include <[^>]+>)%$1%;
    print;
}

现在你可以这样做：

cat sourcefile.cpp | perl ignore-meh.pl | g++ -E | perl restore-meh.pl

这篇关于部分preprocess C或C ++源文件？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！