Data symbols exported from a library come under different linker
logic in the Windows GCC port, as they are not auto-exported from
DLLs like code symbols are. This gives build warnings for all of
the tools using pmDebug/pmProgname (i.e. all of the tools). This
can be avoided by decorating these symbols with the __declspec()
directive. Unfortunately a different header directive is needed
when linking than when compiling the DLL.
This patch removes these warnings by decorating these symbols in
the appropriate way depending on which part of the build is in
progress (using INTERN/EXTERN macros for just the handful of data
symbols exported by libpcp).
Data symbols exported from a library come under different linker
logic in the Windows GCC port, as they are not auto-exported from
DLLs like code symbols are. This gives build warnings for all of
the tools using pmDebug/pmProgname (i.e. all of the tools). This
can be avoided by decorating these symbols with the __declspec()
directive. Unfortunately a different header directive is needed
when linking than when compiling the DLL.
This patch removes these warnings by decorating these symbols in
the appropriate way depending on which part of the build is in
progress (using INTERN/EXTERN macros for just the handful of data
symbols exported by libpcp).
A good reference covering the behaviour of GNU ld on Windows:
http://sourceware.org/binutils/docs-2.17/ld/WIN32.html