• Simon Marlow's avatar
    Generate the C main() function when linking a binary (fixes #5373) · 1df28a80
    Simon Marlow authored
    Rather than have main() be statically compiled as part of the RTS, we
    now generate it into the tiny C file that we compile when linking a
    binary.
    
    The main motivation is that we want to pass the settings for the
    -rtsotps and -with-rtsopts flags into the RTS, rather than relying on
    fragile linking semantics to override the defaults, which don't work
    with DLLs on Windows (#5373).  In order to do this, we need to extend
    the API for initialising the RTS, so now we have:
    
    void hs_init_ghc (int *argc, char **argv[],   // program arguments
                      RtsConfig rts_config);      // RTS configuration
    
    hs_init_ghc() can optionally be used instead of hs_init(), and allows
    passing in configuration options for the RTS.  RtsConfig is a struct,
    which currently has two fields:
    
    typedef struct {
        RtsOptsEnabledEnum rts_opts_enabled;
        const char *rts_opts;
    } RtsConfig;
    
    but might have more in the future.  There is a default value for the
    struct, defaultRtsConfig, the idea being that you start with this and
    override individual fields as necessary.
    
    In fact, main() was in a separate static library, libHSrtsmain.a.
    That's now gone.
    1df28a80
Rts.h 7.93 KB