确定找到头文件的位置

Question

当我使用gcc -v hello.c^*编译时,输出显示以下搜索路径#include:

$ gcc -v hello.c
Apple LLVM version 9.1.0 (clang-902.0.39.2)
Target: x86_64-apple-darwin17.7.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
...
clang -cc1 version 9.1.0 (clang-902.0.39.2) default target x86_64-apple-darwin17.7.0
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /Library/Developer/CommandLineTools/usr/lib/clang/9.1.0/include
 /Library/Developer/CommandLineTools/usr/include
 /usr/include
 /System/Library/Frameworks (framework directory)
 /Library/Frameworks (framework directory)
End of search list.

有没有办法确定使用哪些位置？ 例如,说hello.c包含#include <stdio.h>.我可以手动看到有stdio.h多个位置的版本,大概可以使用不同的功能构造:

$ find /usr/local/include -name "stdio.h"
/usr/local/include/c++/5.5.0/tr1/stdio.h

$ find /Library/Developer/CommandLineTools/usr/include -name "stdio.h"
/Library/Developer/CommandLineTools/usr/include/c++/v1/stdio.h

$ find /usr/include -name "stdio.h"
/usr/include/c++/4.2.1/tr1/stdio.h
/usr/include/sys/stdio.h
/usr/include/stdio.h

在Python中,这看起来像:

>>> import math
>>> math.__file__
'/Users/brad/miniconda3/lib/python3.6/lib-dynload/math.cpython-36m-darwin.so'

---

_{*我在Macbook上,所以gcc实际上似乎是路由clang,虽然它似乎是一个真正的可执行文件而不是符号链接.}

Answer 1

来自gcc手册页:

-H

除了其他正常活动之外,还打印所使用的每个头文件的名称.每个名称都缩进以显示#include堆栈的深度.即使发现它们无效,也会打印预编译的头文件; 一个无效的预编译头文件打印有... x和一个有效的... .