Rajs123 Rajs123 - 2 months ago 18
C++ Question

#define in Boost Jamfiles

This is my project structure:

MainFolder
- Jamroot.jam
- AnotherFolder
- libFolder
- Jamfile.jam
- cpp files


I have an #ifdef in one of the cpp files.
Example:

#ifdef SOMEVALUE
Code
#endif


I need to compile the cpp files with #define in Jamfile. Since, I am having two types of executables (one with #define and one without) I need to do this in Jamfile itself and not cpp code.

I have tried the following, which does not work (unable to find definitions inside #ifdef #endif block):

lib libname : [ glob *.cpp ] : <link>static : <define>SOMEVALUE ;

Answer

Adding a preprocessor definition uses the "define" feature as you've seen given your example. But the feature needs to be specified as a requirement of the target definition. The requirements are specified as the third argument of the target definition not the fourth as in your use case. Hence instead of:

lib
  libname # main-target-name
  : [ glob *.cpp ] # sources
  : <link>static # requirements
  : <define>SOMEVALUE # usage-requirements
  ;

You need to move the "" from the usage requirements to the target requirements:

lib
  libname # main-target-name
  : [ glob *.cpp ] # sources
  : <link>static <define>SOMEVALUE # requirements
  : # usage-requirements
  ;

You can find what all the arguments to the target definition are here.