Re: [PATCH] Remove possibly unused lines from Makefile

[Rich Felker <dalias@libc.org>]

On Thu, Dec 07, 2017 at 03:55:52PM +0000, Nicholas Wilson wrote:
> Hi,
> 
> There are a couple of lines I've had to hack out of the Makefile to
> get Wasm to build. In WebAssembly, we can't use crti.s/crtn.s,
> because the compiler doesn't support raw assembly chunks like that.
> 
> That should be OK, since there are default empty files in
> "crt/{crti,crtn}.c". Those empty files are currently unused, as all
> archs provide the assembly versions. For WebAssembly, I'm happy for
> those empty C files to be used.
> 
> There's some clever stuff at the top of the Makefile to construct
> BASE_SRCS and ARCH_SRCS, and it works fine for WebAssembly: we just
> compile the dummy .c files if the .s files aren't provided by the
> arch.
> 
> The problem is further down the Makefile, where an apparently
> unnecessary dependency is placed on the assembly files. I can't work
> out why these two lines are there, and they need to be removed in
> one way or another for the Wasm build to succeed. Getting rid of
> them doesn't seem to have any negative consequences for the standard
> x86 build.
> 
> Patch below.
> 
> Thanks,
> Nick
> 
> ============
> diff --git a/Makefile b/Makefile
> index d2e89979..308ddaae 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -113,10 +113,6 @@ obj/crt/rcrt1.o: $(srcdir)/ldso/dlstart.c
>  
>  obj/crt/Scrt1.o obj/crt/rcrt1.o: CFLAGS_ALL += -fPIC
>  
> -obj/crt/$(ARCH)/crti.o: $(srcdir)/crt/$(ARCH)/crti.s
> -
> -obj/crt/$(ARCH)/crtn.o: $(srcdir)/crt/$(ARCH)/crtn.s
> -
>  OPTIMIZE_SRCS = $(wildcard $(OPTIMIZE_GLOBS:%=$(srcdir)/src/%))
>  $(OPTIMIZE_SRCS:$(srcdir)/%.c=obj/%.o) $(OPTIMIZE_SRCS:$(srcdir)/%.c=obj/%.lo): CFLAGS += -O3
>  

Looks good. I'm committing this with a message explaining the
historical reasons these lines appeared and why it makes sense to
remove them.

Rich