From a306f8107af7960259dda1a756224d71a338bba9 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Thu, 10 Mar 2016 16:45:55 +0100 Subject: [PATCH] tools/foreign: avoid using alignment directives when not appropriate The foreign header generation blindly replaces 'uint64_t' with '__align8__ uint64_t', to get correct alignment when built as 32bit. This is correct in most circumstances, but Clang objects to two specific uses. * Inside a sizeof() expression * As part of a typecast An example error looks like: /local/xen.git/tools/libxc/../../tools/include/xen/foreign/x86_64.h:204:44: error: 'aligned' attribute ignored when parsing type [-Werror,-Wignored-attributes] __align8__ uint64_t evtchn_mask[sizeof(__align8__ uint64_t) * 8]; ^~~~~~~~~~ /local/xen.git/tools/libxc/../../tools/include/xen/foreign/x86_64.h:13:36: note: expanded from macro '__align8__' ^~~~~~~~~~~ This sedary is sufficient to fix all the bad examples without touching any of the legitimate uses, and is more simple than teaching mkheader.py how to parse C. Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich Acked-by: Wei Liu --- tools/include/xen-foreign/Makefile | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/include/xen-foreign/Makefile b/tools/include/xen-foreign/Makefile index 80a446a527..bb09c93915 100644 --- a/tools/include/xen-foreign/Makefile +++ b/tools/include/xen-foreign/Makefile @@ -34,7 +34,10 @@ x86_32.h: mkheader.py structs.py $(ROOT)/arch-x86/xen-x86_32.h $(ROOT)/arch-x86/ $(PYTHON) $< $* $@ $(filter %.h,$^) x86_64.h: mkheader.py structs.py $(ROOT)/arch-x86/xen-x86_64.h $(ROOT)/arch-x86/xen.h $(ROOT)/xen.h - $(PYTHON) $< $* $@ $(filter %.h,$^) + $(PYTHON) $< $* $@.tmp $(filter %.h,$^) + #Avoid mixing an alignment directive with a uint64_t cast or sizeof expression + sed 's/(__align8__ \(u\?int64_t\))/(\1)/g' -i $@.tmp + $(call move-if-changed,$@.tmp,$@) checker.c: mkchecker.py structs.py $(PYTHON) $< $@ $(architectures) -- 2.30.2