Missing braces in Updates.h macro

[Donald Bruce Stewart]

dons:
> Hey,
> 
> As you might have seen, last night's head on OpenBSD failed with:
> 
>         ../../ghc/compiler/ghc-inplace -optc-O -optc-Wall -optc-W -optc-Wstrict-prototypes -optc-Wmissing-prototypes -optc-Wmissing-declarations -optc-Winline -optc-Waggregate-return -optc-Wbad-function-cast -optc-I../includes -optc-I. -optc-Iparallel -optc-DCOMPILING_RTS -optc-fomit-frame-pointer -H16m -O  -O2 -static -#include Prelude.h -#include Rts.h -#include RtsFlags.h -#include RtsUtils.h -#include StgRun.h -#include Schedule.h -#include Printer.h -#include Sanity.h -#include Storage.h -#include SchedAPI.h -#include Timer.h -#include Itimer.h -#include ProfHeap.h -#include LdvProfile.h -#include Profiling.h -#include Apply.h -fvia-C -dcmm-lint     -c Interpreter.c -o Interpreter.o
>         Interpreter.c: In function `interpretBCO':
>         Interpreter.c:405: syntax error before `const'
>         Interpreter.c:405: `info' undeclared (first use in this function)
>         Interpreter.c:405: (Each undeclared identifier is reported only once
>         Interpreter.c:405: for each function it appears in.)
>         gmake: *** [Interpreter.o] Error 1
> 
> I tracked this down, and it looks like it is barfing on the occurence of
> DECLARE_IPTR(info) in UPD_REAL_IND. A similar situation occurs in
> Schedule.c:3218: "syntax error before `const'". Looks like it is because
> of the decl not appearing at the start of a block. 
> 
> It is still a bit mysterious -- as the head is building fine on linux
> each night. Any gcc hackers know why this could be? I'm using 2.95.3
> here.
> 
> The following patch makes these cases compile.
> 
> -- Don
>         
> ------------------------------------------------------------------------
> --- Updates.h.orig	Thu Sep  2 11:25:31 2004
> +++ Updates.h	Thu Sep  2 11:25:36 2004
> @@ -57,13 +57,15 @@
>     if you *really* need an IND use UPD_REAL_IND
>   */
>  #define UPD_REAL_IND(updclosure, ind_info, heapptr, and_then)		\
> +	{ 								\
>         DECLARE_IPTR(info);						\
>         info = GET_INFO(updclosure);					\
>          AWAKEN_BQ(info,updclosure);					\
>         updateWithIndirection(GET_INFO(updclosure), ind_info,		\
>                               updclosure,				\
>                               heapptr,					\
> -			      and_then);
> +			      and_then); 				\
> +	}

Ah, but it looks like adding braces to the macro then breaks its use Cmm code:

        ../../ghc/compiler/ghc-inplace -H16m -O  -O2 -static -#include Prelude.h -#include Rts.h -#include RtsFlags.h -#include RtsUtils.h -#include StgRun.h -#include Schedule.h -#include Printer.h -#include Sanity.h -#include Storage.h -#include SchedAPI.h -#include Timer.h -#include Itimer.h -#include ProfHeap.h -#include LdvProfile.h -#include Profiling.h -#include Apply.h -fvia-C -dcmm-lint     -c Updates.cmm -keep-tmp-files -o Updates.o
        Updates.cmm:61:160: parse error on input `{'

This is occuring in the use of UPD_REAL_IND, by UPD_SPEC_IND in
UPD_FRAME_ENTRY_TEMPLATE, in Updates.cmm. 

Maybe Simon has a better idea what is going on here?

-- Don