Skip to content

GitLab

Merged
Created by Ben Avison@bavisonDeveloper

Change detail of `C_EXP_HDR` for CModule clients

This macro is used to define the root directory for exported C header files. Previously, when native-compiling, the default setting, if not otherwise overridden by the master makefile, was <cexport$dir>.Interface.h. This is at odds with the cross-compiling case, which defaults to the equivalent string, but without the h subdirectory, for obvious reasons.

Only one component, DHCP, currently overrides C_EXP_HDR, although more will be joining it in the near future. The macro is used internally within rules defined by CModule, but a few components also use it within rules in their master makefiles.

We hereby change the default value to omit the h subdirectory, and permit master makefiles to specify an override value which also omits it (in future it wil be deprecated to include it, and its use will be phased out). There are two reasons for this:

  1. It assists with cross-compilation, since the override can then be expressed identically for both native and cross builds.

  2. It permits the .exphdr.h suffix rule to be re-used when one or more headers need to be exported to a subdirectory of C_EXP_HDR, so long as the headers are present at an equivalent subdirectory in the component source tree, and that subdirectory is on VPATH. This is because $< is set up to include the element of VPATH that matched the rule - but this needs to go before the .h, not after it.

To prepare for this MR, the following must all be merged: