Menu
Is there a way for the preprocessor to detect if the code in current
translation unit uses(or is creating) precompiled headers?
---
The actual problem I'm facing right now is that I'm on a project that is
abusing PCH by precompiling virtually all header files.
That means there is none of
the clear dependency management you can get from #includes and the compile times is awful.
Practically every change will trigger a full rebuild.
The application is way to big to just fix it in one go, and some of the old guys refuses
to belive that precompiling everyting is bad in any way. I will have to prove it first.
So I must do it step by step and make sure my changes does not affect
code that is compiled the old PCH way.
My plan is to do ifdef out the PCH.h and work on the non PCH version whenever I have some time to spare.
#ifdef USES_PCH
#include "PCH.h"
#elif
// include only whats needed
#endif
I would like to avoid defining USES_PCH at command line and manually keep it in sync with /Y that, besides from not being very elegant, would be a pain. There is a lot of configurations and modules to juggle with and a lot of files that don't follow project defaults.
923
In the project property pages, the options are located under Configuration Properties > C/C++ > Precompiled Headers.
Usage of precompiled headers may significantly reduce compilation time, especially when applied to large header files, header files that include many other header files, or header files that are included in many translation units.
To turn off precompiled headersSelect the Configuration properties > C/C++ > Precompiled Headers property page. In the property list, select the drop-down for the Precompiled Header property, and then choose Not Using Precompiled Headers.
To make builds faster, GCC allows users to `precompile' a header file; then, if builds can use the precompiled header file they will be much faster. To create a precompiled header file, simply compile it as you would any other file, if necessary using the -x option to make the driver treat it as a C or C++ header file.
If Visual C++ defined a constant to indicate whether precompiled headers were in use, it would probably be listed in Predefined Macros. And it's not documented there, so it probably doesn't exist. (If it does exist, it's probably undocumented and may change in a future version.)
154
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
