How to make GCC search for headers in a directory before the current source file's directory?

Question

I am using GCC precompiled headers in my project with multi-architecture build, but things break down when I try to place it in a directory different from current source\'s dire

Answer 1

I have found a workaround.

1. Build a precompiled header under a different name. For example is the header is a.h, original precompiled header is pchdir.i686/a.h.gch, build it as

   gcc a.h -o pchdir.i686/a-precompiled.h.gch
   

2. Use GCC's -include switch to make sure the renamed header is included before anything else (even before the original a.h), e.g.

   gcc -Ipchdir.i686 -include a-precompiled.h <other arguments> <source>
   

3. Final inclusion order in the source file will be: a-precompiled.h.gch, a.h, which I've checked with -H. Original header is included, but is not actually processed because precompiled header has identical include guards (verified as well by inserting an #error in the original header after building the precompiled one).