Generate the C main() function when linking a binary (fixes #5373)

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.

1 files changed, 0 insertions, 24 deletions

diff --git a/rts/Main.c b/rts/Main.c
deleted file mode 100644
index c7a559fc14..0000000000
--- a/rts/Main.c
+++ /dev/null
@@ -1,24 +0,0 @@
-/* -----------------------------------------------------------------------------
- *
- * (c) The GHC Team 2009
- *
- * The C main() function for a standalone Haskell program.
- *
- * Note that this is not part of the RTS. It calls into the RTS to get things
- * going. It is compiled to a separate Main.o which is linked into every
- * standalone Haskell program that uses a Haskell Main.main function
- * (as opposed to a mixed Haskell C program using a C main function).
- *
- * ---------------------------------------------------------------------------*/
-
-#include "PosixSource.h"
-#include "Rts.h"
-#include "RtsMain.h"
-
-/* Similarly, we can refer to the ZCMain_main_closure here */
-extern StgClosure ZCMain_main_closure;
-
-int main(int argc, char *argv[])
-{
-    return hs_main(argc, argv, &ZCMain_main_closure);
-}