[Scons-users] update dependency and signatures.dblite after biilding

[Mats Wichmann]

On 6/6/25 09:46, 于 wrote:
> 
> ‍‍My problem:
> ‍
> 
>     In my project, there are those code in some source files,
> 
>     #defineFOO_HEADER "foo.h"
>     #includeFOO_HEADER
> 
> ‍‍
> 
>     and the files are independent module, I can't modify them.
> 
>     the scons-user.pdf said, scons the built-in C scanner is unable to
>     extract the implicit dependency on a header file.
>     So I create .d file for every source file, and parse dependencies
>     from .d, and then add dependency by Depends function.
> 
>     ‍‍And then, there is a new problem, when there are no .d, (for
>     example the first building or dependencies are changed), I need to
>     build project with two times, and then I can push all the
>     dependencies into signature.

yes, this isn't ideal - if the dependencies can't be automatically 
determined, you have both a first-run problem and no detection of changes.

> 
>     ‍‍
>     So I consider that whether could I update all the dependencies into
>     signature with just one building.
>     that is my problem.
> 
Well, this is why Bill advised trying the C Conditional Scanner, which 
*does* know how to handle preprocessor instructions of this sort.  It's 
still a bit of a work in progress (there are some questions about 
recursion, in particular), which is why it's not the default.  Were you 
able to try that out?