Date: Tue, 12 Jun 2012 20:11:56 +0200 (CEST) From: Juergen Lock <nox@jelal.kn-bremen.de> To: bfalk_bsd@brandonfa.lk Cc: freebsd-emulation@freebsd.org Subject: Re: Building QEMU with clang Message-ID: <201206121811.q5CIBugV088678@triton8.kn-bremen.de> In-Reply-To: <4FD67192.2010001@brandonfa.lk>
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In article <4FD67192.2010001@brandonfa.lk> you write:
>Greetings,
Hi!
>
>I could go on a rant, but I'll keep it short and sweet. I'm wondering if
>there are any efforts to get QEMU building with clang. I know this
>should go on the QEMU mailing lists, but I wanted to post it here as
>well as I'd be using FreeBSD as the host.
>
>When working with qemu-devel (with --enable-tcg-interpreter), I get:
>
>multiboot.S:31:8: error: .code16 not supported yet
>
>multiboot.S:123:17: error: unexpected token in argument list
> data32 lgdt %gs:6
> ^
>multiboot.S:131:15: error: unknown token in expression
> data32 ljmp *%gs:0
>
>Now, code16 is a pretty big deal, and that's obviously a feature that
>clang needs to add. However what is it with the complaints of the other
>two (I'm an Intel syntax guy, not AT&T :P)?
>
I don't know about those but I do know clang can be told to call (g)as
instead of using its internal assembler by passing -no-integrated-as.
>Semi-sidenote:
>Since clang does not support global registers, --enable-tcg-interpreter
>has to be specified to ./configure. This should be added to the port as
>an option.
Heh I didn't know about --enable-tcg-interpreter... The following
patch makes the port build, but the result is much slower than with
gcc. (and without --enable-tcg-interpreter.) And also halt -p in a
FreeBSD guest causes qemu-system-x86_64 to fail with a tcg error.
I'm not sure it makes much sense to commit this nevertheless...?
Index: Makefile
===================================================================
RCS file: /home/pcvs/ports/emulators/qemu-devel/Makefile,v
retrieving revision 1.140
diff -u -p -r1.140 Makefile
--- Makefile 9 Jun 2012 16:19:05 -0000 1.140
+++ Makefile 12 Jun 2012 17:57:16 -0000
@@ -48,11 +48,19 @@ ADD_AUDIO_DESC= "Emulate more audio har
ALL_TARGETS_DESC= "Also build bsd-user targets (for testing)"
OPTIONS_DEFAULT=SDL OPENGL GNUTLS SASL JPEG PNG CURL CDROM_DMA PCAP
-.include <bsd.port.options.mk>
+.include <bsd.port.pre.mk>
CONFIGURE_ARGS+= --extra-ldflags=-L${LOCALBASE}/lib
PORTDOCS= docs qemu-doc.html qemu-tech.html
+# XXX this fixes build with clang but --enable-tcg-interpreter that's
+# needed to avoid global register usage that clang doesn't support
+# causes the result to be slow.
+.if ${CC:T:Mclang} == "clang"
+CONFIGURE_ARGS+= --enable-tcg-interpreter
+CLANG_CFLAGS_AS+= -no-integrated-as
+.endif
+
.if empty(PORT_OPTIONS:MALL_TARGETS)
CONFIGURE_ARGS+= --disable-bsd-user
PLIST_SUB+= ALLTARGETS="@comment "
@@ -191,6 +199,9 @@ post-patch:
-e "s|^(LDFLAGS=).*|\1${LDFLAGS}|" \
${WRKSRC}/Makefile
@${REINPLACE_CMD} -E \
+ -e "s|^(CFLAGS[ ]*:=.*)|\1 ${CLANG_CFLAGS_AS}|" \
+ ${WRKSRC}/pc-bios/optionrom/Makefile
+ @${REINPLACE_CMD} -E \
-e "1s|^(#! )/usr/bin/perl|\1${PERL}|" \
${WRKSRC}/scripts/texi2pod.pl
@@ -217,4 +228,4 @@ post-install:
fi
@${CAT} ${PKGMESSAGE}
-.include <bsd.port.mk>
+.include <bsd.port.post.mk>
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